JPH07164506A - Flexible flat die for extrusion molding - Google Patents

Abstract

PURPOSE:To increase the thickness adjusting quantity of a sheet by adjusting the gap between lips, to enhance gap adjusting accuracy and to facilitate the assembling work of a gap adjusting device. CONSTITUTION:In a flexible flat die for extrusion molding displacing a flexible lip 2 toward a gap 4 by the axial movement of the adjusting screw of a connector 9 due to the left and right rotation of the adjusting screw 8 attached to a non-flexible block part 6, the hook 12 integrally fixed to the flexible lip 2 by a stop screw 11 is attached at the axial position of the adjusting screw of the flexible lip 2 in the state hooked with the flexible lip 2 and the connector 9 is integrally attached to the hook 12 by screws 13, 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible flat die for extrusion molding capable of extruding a heat-melted thermoplastic resin into a sheet shape and adjusting the thickness of the sheet.

[0002]

2. Description of the Related Art Conventionally, a heat-melted thermoplastic resin is extruded into a sheet shape from a gap formed between lips of a flat die of an extruder, and a gap between the lips is adjusted so that a sheet thickness can be adjusted. An example of a flexible flat die for extrusion molding is disclosed in Japanese Utility Model Publication No. 3-77623. This will be described with reference to FIGS. 4 and 5. By combining the die body 101 and the die body 102 so as to face each other, a resin flow path 120 is formed, and a flexible lip 101 ′ at the tip of the die body 101 is formed. Die body 10
The resin discharge port 121 is formed by the front end portion of 2.
A holding block 103 for holding the adjustment bolt 110 is fixed to the side portion of the die body 101 with a bolt 119. The holding block 103 may be integrally formed on the die body 101. Further, the tip of the stud bolt 105 is screwed onto the surface of the die body 101 opposite to the flow path surface of the flexible lip 101 ′, and is fixed by the lock nut 106. Further, at the base end of the stud bolt 105, a collar portion 124 and a screw 126 for holding the disc spring 108 are provided.
The base end side of the stud bolt 105 is a holding block 103.
It is installed in a state in which it is inserted into the screw hole 125 formed in the. A disc spring 108 is inserted into the lower surface of the collar portion 124, and the screw seat 10 is provided to apply a spring force to the disc spring 108.
7 is screwed into the screw hole 125 of the holding block 103.

On the outside of the holding block 103, there is provided an adjusting bolt 110 into which a screw 126 at the base end of the stud bolt 105 is screwed, and an outer diameter side screw of the adjusting bolt 110 (to the stud bolt). A fixing nut 111 is screwed to the screwing side screw (which has a different pitch), and the fixing nut 111 is appropriately attached to the holding block 103 by a bolt (not shown) via a holding plate 112. It is fixed in position and attached. In addition, the holding plate 11
As shown in FIG. 5, two fixed nuts 111 are adjacent to each other.
It is divided so that it can be pressed across. The adjusting bolt 1
10 and fixing nut 111 are combined, and stud bolt 1
The locking pin 113 is locked to the collar 124 of No. 05 so as to prevent the stud bolt 105 from rotating with respect to the holding block 103, and the fixing nut 111 is fixed to the holding block 103 so as not to rotate. , A differential screw type adjustment bolt, and by loosening the screw seat 107 with respect to the holding block 103, the disc spring 10
After freeing 8, the adjustment bolt 110 is rotated to finely adjust the tip position of the stud bolt 105, and then the screw seat 107 is tightened to apply a required spring force to the disc spring 108. Allows lip adjustment with no play on the screw. In addition, 117 is a heat retention cover.

Further, the heater 104 for heating the stud bolt 105 is formed in a tubular shape, and the tubular heater 10 is also provided.
The inner diameter of 4 is processed so as to fit the outer circumference of the stud bolt 105, and the heater 104 is connected to the stud bolt 105.
It is installed on the outer circumference of. The heat transfer between the heater 104 and the die body 101 is minimized via a heat insulating material 118. In addition, the heat-retaining cover 117
Is the flexible lip 101 ′ and the collar portion 12 of the die body 101.
The air gap 123 surrounded by 2 is substantially sealed and plays a role of heat retention to prevent heat radiation from the stud bolt 105 and the like. Reference numeral 114 denotes an air supply / exhaust jacket, which is provided to form an air supply passage for cooling the heater 104 for heating the stud bolt 105 and to shield the heater 104 from outside air. Is provided so as to cover the entire width of the die and supplies air uniformly over the entire width. Further, air is supplied from the air supply port 115 for cooling, passes through a hole 115-1 that is appropriately formed over the entire width, passes through a ventilation path 115-2, and extends from the lower ventilation hole 115-3 to the outer periphery of the heater 104. Air is supplied and is discharged from the exhaust port 116 while cooling the heater 104 through the ventilation passage 115-4. Thus, the heater 10
By cooling 4, the stud bolt 105 is also cooled. The stud bolts 105 and the adjusting bolts 110 have appropriate shapes, and the stud bolts 105 and the flexible lips 10 are used.
Heat insulating materials (ceramic or stainless steel) 134 and 135 are provided in the connecting portion 1'to prevent heat or cooling heat for the stud bolt 105 from being transmitted to the flexible lip.

In the conventional example, the adjusting bolt device is provided with a stud bolt 105 by means of a disc spring 108.
Since a force in the pulling direction (a force in the direction pulling the flexible lip 101 ') is constantly applied to the adjustment bolt 110, the adjustment bolt 110 receives a force in the direction to push the stud bolt 105, and the adjustment bolt 110 is pulled in the pulling direction. When the screw rotates, the force on the pulling side due to the screw cannot be applied while the screw has backlash, but the force of the disc spring 108 causes the stud bolt 105 to rotate.
The pulling force is applied to. The force and adjustment amount of the disc springs 108 can be appropriately adjusted by increasing or decreasing the number of disc springs in parallel and the number of disc springs in series. Therefore, the required number may be selected and installed. As described above, since the adjusting bolt 110 is constantly applied with the force in the same direction by the disc spring 108, there is no play of the screw at the time of switching between push and pull.

Further, in the case of automatic adjustment by heating and cooling the stud bolt 105, when the stud bolt 105 is heated and expanded, the upper end of the stud bolt 105 is pressed by the adjusting bolt 110. The extension directly acts as a force to push the flexible lip 101 ', while when the stud bolt 105 is cooled and contracted, the proximal end screw of the stud bolt 105 moves in the playing direction, but it is pushed upward by the force of the disc spring 108. Since the force is applied, the force acts in the direction of pulling the flexible lip 101 ', and it is possible to perform both push and pull. Since the adjusting bolt 110 is always applied with a force in the same direction by the disc spring 108, there is no play of the screw at the time of switching between push and pull. Further, since the screw has a structure with no play, the amount of expansion and contraction of the stud bolt 105 is small, and even if only one heater is disconnected and the stud bolt 105 contracts, the disc spring 108 has a sufficient amount of flexure. Since it is absorbed, a force greater than the reaction force of the disc spring 108 is not applied, and the stud bolt 10 at the time of heater disconnection, which is the greatest problem in the case of dual push and pull,
5 can be prevented from being damaged.

[0007]

However, in the above-mentioned conventional flexible flat die, the adjusting bolt 110 is rotated, or the stud bolt 105 is heated and cooled to displace the flexible lip 101 'back and forth, which causes the resin to move. Although the sheet thickness is adjusted by adjusting the gap of the discharge port 121, as a practical matter, as shown in FIG. 4, the mounting pitch of the stud bolt 105 to the flexible lip 101 'is made as small as possible. Flexible lip 10
If the thickness of 1'is thick, the rigidity becomes large, and as shown in FIG. 5, the larger the displacement amount with respect to the flexible lip 101 'between the mounting pitches between the stud bolts 105 adjacent to each other, the smaller the error. However, there is a drawback that the extrusion thickness in the width direction is not constant due to a difference, and as a result, the effective thickness adjustment amount of the sheet becomes small. The stud bolt 105 fixed to the flexible lip 101 ′ with the lock nut 106 is formed by the rotation stop pin 113 so as not to rotate with respect to the holding block 103. However, when the lock nut 106 is actually tightened and the slit position of the stud bolt 105 is to be aligned with the anti-rotation pin 113 position, it is necessary to prevent the stud bolt 105 from rotating along with the final tightening. However, there are drawbacks such that the tightening is easy and the work requires considerable skill. In addition, the flexible lip 10
The use of the elongated stud bolt 105 for pushing and pulling 1'has a drawback in that the stud bolt 105 itself may be distorted and the adjustment may be unstable, particularly when pushing. Therefore, the present invention solves the above-mentioned conventional problems, increases the amount of sheet thickness adjustment by adjusting the gap between lips, and rotates the adjusting screw to the left and right to facilitate the assembly work of the gap adjusting device. The present invention is intended to provide a flexible flat die for extrusion molding which can be manufactured.

[0008]

Therefore, according to the present invention, a thermoplastic resin which has been heated and melted is extruded into a sheet form from a gap formed between lips of a flat die of an extruder, and the gap between lips is adjusted. In order to make the thickness of the sheet adjustable, one of the two facing lips is formed as a flexible lip in which a groove is formed outside the tip of the lip to bend the tip of the lip in the gap adjusting direction, and the lip is separated by the groove. Between the non-flexible block portion and the flexible lip of the flat die, the flexibility is provided by the axial movement of the adjustment screw of the connecting body due to the left-right rotation of the adjustment screw attached to the non-flexible block portion. In a flexible flat die for extrusion molding that displaces the lip in the gap direction, a flexible lip is formed by a set screw in a hook-shaped engagement with the flexible lip at the axial center position of the adjustment screw of the flexible lip. Together A flexible flat die for extrusion molding in which the hook is fixed to the hook, and the connecting body is integrally attached to the hook by a screw, and a screw for integrally fixing the connecting body and the hook is It serves as a set screw that is integrally fixed to the flexible lip, and serves as a means for solving the problem.

[0009]

With the flexible flat die for extrusion molding of the present invention having the above-described structure, even if the hook is formed with a screw hole for a set screw, the flexible lip does not have a screw hole, so that the flexible lip is flexible. The thickness of the sex lip can be considerably reduced as compared with the conventional one. Therefore, even if the adjustment screw is rotated to increase the displacement amount of the flexible lip, the flexible lip can be uniformly displaced in the width direction. And you can get enough. Also, even if the connecting body is locked in the block so that the connecting body can move in the axial direction of the adjusting screw by rotating the adjusting screw to the left and right, the connecting body and the hook can be screwed together with the hook. Since they are separated so as not to be associated with the screw fixing to the flexible lip, they can be assembled in a sufficiently screwed state without requiring skill. Also, since the screw for attaching the hook to the flexible lip is separate from the connecting body, the connecting body can be formed with sufficient rigidity even if it is long in the axial direction of the adjusting screw. It is possible to obtain stable adjustment of the sheet thickness against pushing and pulling of the connected body by the screw.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. A gap 4 is formed between the lips 2 and 3 of the flat die 1 of the extruder for extruding the heat-melted thermoplastic resin into a sheet. In order to make it possible to adjust the gap 4 between the lips 2 and 3 to adjust the thickness of the sheet, one of the two lips 2 and 3 facing each other has a groove 5 on the outside of its tip.
Is formed, and the tip of the lip 2 is formed as a displaceable flexible lip 2 that bends in the gap adjusting direction. Between the non-flexible block portion 6 and the flexible lip 2 of the flat die 1 separated by the groove 5, left and right of the adjusting screw 8 attached to the fixing nut 7 on the non-flexible block portion 6. The flexible lip 2 is slightly displaced in the gap direction by the axial movement of the adjusting screw 8 of the differential screw type of the connecting body (in the case of this embodiment, the connecting rod 9 having threads formed at both ends) by rotation. A gap adjusting device 10 is attached.

That is, at a position on the axial center of the adjusting screw 8 for adjusting and displacing with the flexible lip 2, a flexible screw is provided by a set screw 11 in a hooked state with the groove 2a of the flexible lip 2. The hook 12 is attached in a state of being fixed integrally with the hook 2, and the tip of the connecting rod 9 is screwed to the hook 12 while being screwed into the same screw hole 13 as when the set screw 11 is attached,
Also, the screw hole 13 that is double-tightened by the nut 14, that is, the screw hole 13 that integrally fixes the connecting body 9 and the hook 12 is a set screw hole 13 that integrally fixes the hook 12 to the flexible lip 2. Has been done. Reference numeral 15 is fitted with a slit 17 formed in a large-diameter portion 16 of the connecting rod 9 and attached to a holding block 21 fixed with a non-flexible block portion 6 and a bolt 20 so that the connecting rod 9 can be prevented from rotating. A plurality of disc springs are provided between the stepped portion of the large diameter portion 16 of the connecting rod 9 and the screw seat 22 screwed to the holding block 21 to prevent backlash of the screw. Is.

The operation of the embodiment configured as described above will be described. In the gap adjusting device 10 of the flexible flat die 1 for extrusion molding, the hook 12 is formed with the screw hole 13 for the set screw 11. However, since the groove 2a for hook engagement is only formed in the flexible lip 2 and the screw hole is not formed, the thickness of the flexible lip 2 in the adjusting direction is made considerably thinner than the conventional one. Therefore, the effective adjustment amount can be increased. As a result, even if the amount of displacement of the flexible lip 2 due to the rotation of the adjusting screw 8 increases, the flexible lip 2 is uniformly displaced in the width direction, so that the extrusion thickness at each lip portion in the width direction is increased. Can be made constant, and the amount of adjustment of the effective thickness of the sheet can be sufficiently obtained as compared with the conventional case.

Further, even if the main body of the connecting rod 9 is prevented from rotating by the non-flexible block portion 6 so that the connecting rod 9 can be moved in the axial direction of the adjusting screw 8 by the left-right rotation of the adjusting screw 8, 9 and hook 12 is screwed,
Since the set screw 11 is a separate body from the connecting rod 9 and is separated so as not to be related to the screw fixing of the hook 12 and the flexible lip 2, it does not require any skill and is sufficient for each. The gap adjusting device 10 can be assembled in a state where the gap adjusting device 10 is screwed to. Further, a set screw 11 for attaching the hook 12 to the flexible lip 2 and a connecting rod 9
Since it is a separate body from the adjusting screw 8, it can be formed with sufficient rigidity even if the connecting rod 9 is long in the axial direction of the adjusting screw 8. Therefore, it is possible to stably adjust the sheet thickness.
Needless to say, the thickness of the sheet can be automatically adjusted by the expansion and contraction of the connecting rod 9 by the heater 23 and the cooling air.

Next, a second embodiment of the present invention will be described with reference to FIG. 3. In the second embodiment, instead of the connecting rod 9 of the first embodiment, a quadrangular cross section having a heater (not shown) built in is connected. Implant bolts 25 and 26 are screwed to both ends of the rod 19 and tightened with nuts 27 and 28, and the tip of the front implant bolt 25 is screwed into the screw hole 13 of the hook 12 and tightened with the nut 14. As a result, the structure, action and effect are almost the same as those of the first embodiment except that the gap adjusting device is formed by combining short parts. Book second
In the case of the embodiment, connecting rods 19 are made by combining short parts.
As a result, the flexibility in dimensional design is increased, and the flexibility in adjustment responsiveness is increased by selecting the thickness of the connecting rod that is the main component and the material with an appropriate coefficient of thermal expansion. be able to.

[0015]

As described in detail above, according to the present invention, the amount of sheet thickness adjustment by adjusting the gap between the lips is increased, and the adjusting screw is rotated left and right to improve the gap change accuracy. In the state, and without requiring skill,
There is an effect that the assembling work of the gap adjusting device can be facilitated.

[Brief description of drawings]

FIG. 1 is a side sectional view of a gap adjusting device in a flat die showing a first embodiment of the present invention.

FIG. 2 is an enlarged detailed view of a main part of FIG.

FIG. 3 is a side sectional view of a gap adjusting device in a flat die according to a second embodiment of the present invention.

FIG. 4 is a side sectional view of a gap adjusting device in a conventional flat die.

5 is a view on arrow A in FIG. 4. FIG.

[Explanation of symbols]

 1 Flat Die 2 Flexible Lip 2a Groove 3 Lip 4 Gap 5 Groove 6 Non-Flexible Block 7 Fixing Nut 8 Adjusting Screw 9 Connecting Rod 10 Gap Adjusting Device 11 Set Screw 12 Hook 13 Screw Hole 14 Nut 15 Rotating Screw 16 Large Diameter Part 17 Slit 18 Disc Spring 19 Connecting Rod 25, 26 Implant Bolt 27, 28 Nut 29 Gap Adjusting Device

Claims (2)

[Claims] 1. A heat-melted thermoplastic resin is extruded into a sheet shape from a gap formed between lips of a flat die of an extruder, and a gap between lips is adjusted so that a thickness of a sheet can be adjusted. One of the two facing lips,
A groove is formed on the outside of the tip portion to form a flexible lip whose tip portion bends in the gap adjusting direction, and between the non-flexible block portion and the flexible lip in the flat die separated by the groove, A flexible flat die for extrusion molding in which the flexible lip is displaced in the gap direction by the axial movement of the adjusting screw of the connecting body by the left-right rotation of the adjusting screw attached to the non-flexible block. A hook fixed integrally with the flexible lip by a set screw is attached at a position on the axial center of the adjusting screw in a hook shape with the flexible lip, and the connecting body is integrally integrated with the hook by the screw. Flexible flat die for extrusion characterized by being attached. 2. The extrusion molding flexible according to claim 1, wherein the screw hole for integrally fixing the connecting body and the hook is a set screw hole for integrally fixing the hook to the flexible lip. Shaped flat die.