JPH0615012Y2 - Extrusion die lip adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an unstretched film (or sheet) manufacturing apparatus and an extrusion molding die lip adjusting apparatus that can be used in a stretched film manufacturing apparatus.

(Prior Art) Conventionally, the tip of an adjusting bolt is fixed to or brought into contact with a flexible lip, and a thermal displacement unit fixed to a die body via a heat insulating material is adiabatically connected to the bolt to heat and
There is known a thermal displacement type lip adjusting device which automatically pushes and pulls a flexible lip to adjust a lip gap by utilizing a difference in thermal displacement amount between a thermal displacement unit and an adjusting bolt during cooling.

However, many problems remain to be solved in the above-mentioned device, for example, one of them has a problem of difficulty in fine adjustment by manual operation due to backlash of the screw portion, and further, the adjustment bolt itself is a thermal displacement unit. Since it is heated / cooled indirectly via the, the relative movement due to the difference in thermal displacement between the two becomes slower, and it is difficult to expect proper lip adjustment.In addition, the space for installing the thermal displacement unit makes it possible to adjust the spacing between adjacent adjustment bolts. There was a problem such as having to increase the size.

As a result of diligent research to overcome these problems, the present inventors have developed a new lip adjusting device that solves not only the above problems but also other problems (Japanese Patent Application No.
36020).

FIG. 3 shows a cross section of the same apparatus. To explain the configuration, a resin flow path 120 is formed by combining the upper die body 101 and the lower die body 102, and the upper die body 1 is formed.
01 The resin discharge port 121 is formed by the flexible lip 101 'at the tip and the tip of the lower die body 102. A holding block 103 for holding the adjustment bolt is fixed to the outside of the upper die body 101 by a bolt 119.

On the other hand, a large number of stud bolts 105 are screwed through the heat insulating material 134 (ceramic screw part or stainless steel helisert) over the entire width of the die on the surface opposite to the flow path surface of the flexible lip 101 ′ at the tip of the upper die body 101. With
It is fixed via a heat insulating material 135 by a lock nut 106. At the other end of the stud bolt 105, a flange portion 124 for installing the disc spring 108 is provided.
Is installed in a screw hole 125 formed in the holding block 103. A disc spring 108 is provided on the lower surface of the collar portion 124.
Is inserted, and the screw seat 107 is screwed into the screw hole 125 of the holding block 103 in order to apply a spring force to the disc spring 108.

Further, on the outside of the holding block 103, a large-diameter adjustment bolt 110 in which a small-diameter adjustment bolt 109 is screwed into the inner diameter side is provided, and an outer diameter side screw of the same large-diameter adjustment bolt 110 (a pitch different from that of the inner screw is provided. ) Is screwed with the fixing nut 111,
The fixing nut 111 is fixedly attached to the holding block 103 by a bolt (not shown) via a holding plate 112.
The pressing plate 112 is divided so as to press over the fixing nuts 1112 as shown in FIG. The adjusting bolt
109, 110 and fixing nut 111 combined, small diameter adjustment bolt 10
Holding block for 9 is provided with anti-rotation pin 113
It is installed so that it does not rotate with respect to 103, and the fixed nut 111 is also fixedly installed on the holding block 103 so that it does not rotate.
After loosening 7 with respect to the holding block 103 and freeing the disc spring 108, the large diameter adjustment bolt 110 is turned to finely adjust the tip of the small diameter adjustment bolt 109 to finely adjust the tip position of the stud bolt 105. After that, the screw seat 107 is tightened to apply a required spring force to the disc spring 108, thereby performing manual adjustment.

On the other hand, a heater 104 for heating the stud bolt 105 is formed in a tubular shape, and an inner diameter is processed so as to fit the outer periphery of the stud bolt 105, and the heater 104 is installed on the outer periphery of the stud bolt 105. In addition, a heat insulating material is provided between the heater 104 and the die body 101.
118 is provided to minimize the heat exchange between the two. In the figure, 117 is a heat insulating plate, which is a flexible lip 101 '.
And the space 123 surrounded by the collar portion 122 of the die body 101 is substantially sealed, and at the same time, it plays a role of heat retention for preventing heat radiation from the stud bolt 105 and the like. Further, 114 is an exhaust jacket, which is a heater 104 for heating the stud bolt 105.
In addition to providing an air supply passage for cooling the, the heater 104 is provided to shut off from the outside air,
It is provided so as to cover the entire width of the die, supplies air from an air supply port 115 for supplying air uniformly over the entire width, passes through a hole 115-1 that is appropriately opened over the entire width, and passes through a ventilation path 115-2 to a lower portion. Pore 115-
Air is supplied to the outer periphery of the heater 104 from 3 and is exhausted from the exhaust port 116 while cooling the heater 104 through the ventilation passage 115-4. By cooling the heater 104 in this way, the stud bolt 105 is also cooled.

Further, in the case of automatic adjustment by heating / cooling the stud bolt 105, if the stud bolt 105 is heated and expanded,
Since the upper end of the stud bolt 105 is pressed by the small diameter adjustment bolt 109, the expansion of the stud bolt 105 directly acts as a force to push the flexible lip 101 ′, and when the stud bolt 105 is cooled and contracted, the upper end of the stud bolt 105 is removed from the adjustment bolt 109. Although it moves in the away direction, the pushing force is applied upward by the force of the disc spring 108. Therefore, the force acts in the pulling direction of the flexible lip 101 ', and the push-pull can be used for both. Since the adjusting bolts 109 and 110 are constantly applied with force by the disc spring 108 in the same direction, there is no screw play at the time of conversion of push and pull.

In addition, the stud bolt 105 and the adjustment bolt 109,1
Since 10 parts are separated, even if only one heater is disconnected and the stud bolt 105 contracts a large amount, it is absorbed by the margin of the flexing amount of the disc spring 108.
Therefore, it is possible to prevent the adjustment bolts 109 and 110 from being damaged when the heater is disconnected, which is the greatest problem in the case of both push and pull. Further, in the adjusting bolt device, since the stud bolt 105 and the adjusting bolts 109 and 110 are separated, the pulling side force by the screw cannot be applied, but the disc spring 108 is provided to apply the pulling direction force. , Turn the adjusting bolts 109, 110 in the direction to loosen them, and the disc spring 108
The pulling force is applied to the stud bolt 105 by the force of. 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 (two in FIG. 3). It shows a case where two sets in which are stacked in parallel are combined in parallel.

(Problems to be Solved by the Invention) As a result of further studies on the above-mentioned device having such an excellent function, the following points remained as problems. That is,
The above-mentioned device also has the function of adjusting the lip opening in the width direction of the extrusion die by heating and cooling the stud bolt, but the adjustment time is the response speed of expansion and contraction due to heating and cooling of the stud bolt. It was found that it is important to increase the cooling rate as one of the points for increasing the response speed.

Therefore, the object of the present invention is to improve the parts other than the gist of the extrusion molding die lip adjusting device (Japanese Patent Application No. 1-36020) already proposed, and to further improve the adjustment time by this kind of thermal displacement type die lip adjusting device. It is about shortening.

(Means for Solving the Problems) In order to achieve this object, the present invention is provided with a plurality of molten resin sheets or film extrusion molding dies in the die lip width direction, and utilizes thermal expansion and thermal contraction of stud bolts. In the thermal displacement type lip adjusting device that adjusts the lip gap,
A cylindrical heater that is fitted onto each of the stud bolts and directly heats the stud bolts. A small gap is provided between the heater and the die body, and a gap is provided between the heater and the die body. And a cooling jacket disposed on the outside air side of the heater and fixed to the die body with a minute gap communicating with the heater between the heater and the outside air. A configuration is adopted in which cooling air passages that communicate with individual minute gaps formed on the outer periphery of each heater are provided.

That is, the present invention is such that a cylindrical heater is attached to each stud bolt, and the following improvements are made in order to increase the cooling capacity on the outside of the heater.

(1) Increase the cooling capacity by reducing the gap between the outer periphery of each heater and increasing the flow velocity of cooling air.

(2) An inlet for each air is provided for each heater to ensure that the cooling air reaches each heater.

(3) A heat insulating material is provided between the heater and the die body. To further improve the heat insulating effect, a space is provided between the heat insulating material and the die body to interpose an air layer.

(Operation) In the present invention, since the stud bolt is directly heated by the heater, the temperature rising rate is high, and accordingly, the adjustment time for narrowing the lip interval is naturally shortened. The problem is to increase the cooling speed of the stud bolts. Therefore, in the present invention, the cooling means described above is adopted to increase the cooling capacity of the stud bolts by increasing the cooling capacity on the outer side of the tubular heater. The response of expansion and contraction is improved, the lip opening in the width direction of the die lip is easily adjusted, and the time for adjusting the thickness of the final plastic sheet or film is shortened.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show a typical embodiment of the present invention. FIG. 1 is a side sectional view of a die lip adjusting device, and FIG. 2 is a sectional view taken along line B of FIG.

The present invention has been improved based on the previous proposal (Japanese Patent Application No. 1-36020) made by the present inventors as described above, and the third embodiment has already been described in detail in the embodiment apparatus shown in FIG. The device shown in the figure and most of it are substantially the same, and in FIG.
Other parts that are the same as corresponding parts in FIG. 3 are not labeled.

Therefore, in the following description, the description will be focused on the parts denoted by the reference numerals in FIGS. 1 and 2, and detailed description of the other parts will be omitted.

The tip of the stud bolt 5 is screwed into the upper surface side of the flexible lip 1 ′ located at the frontmost part of the upper die body 1 via a heat insulating material and fixed by a lock nut. Further, a flange portion is provided at the base end of the stud bolt 5, a countersink is interposed between the flange portion and the screw seat, and the screw seat is provided with a holding block fixed to the upper part of the upper die body 1 by a bolt. It is screwed into the screw hole.

On the other hand, a large-diameter adjustment bolt in which a small-diameter adjustment bolt is screwed into the inner diameter portion is inserted into the hole of the holding block, and the end surface of the small-diameter adjustment bolt is brought into contact with the surface of the flange portion of the stud bolt 5. The large diameter adjustment bolt is fixed to the holding block by a fixing nut.

The above is the same as the above-mentioned proposal example by the present inventors shown in FIG.

In addition to the above-mentioned configuration, the apparatus of this embodiment has the configuration shown in FIGS.
As clearly shown in the drawing, a large number of cylindrical heaters 4 in which a large number of stud bolts 5 are densely inserted are arranged side by side in the width direction of the die body 1, and between the heaters 4 and the die body 1, respectively. A heat insulating material that forms the air passages 15-4 and the voids 19.
18 are inserted. Further, an exhaust jacket 14 is installed on the entire width of the die body 1 on the side of the heater 4 which is in contact with the outside air, leaving a minute gap to serve as an air passage 15-4. An air supply port 15 extending over the entire length is provided, and the air supply from the air supply port 15 is performed by the jacket 14
Through each of the air passages 15-1 to 15-3 and an air passage 15-4 provided on the outer peripheral surface of each of the heaters 4, 4, ... Then, the outer peripheral surface of each heater 4, 4 ... and the jacket 14
And the air passage formed between the heat insulating material 18 and the heat insulating material 18 is an exhaust port.
It leads to 16.

Here, in the present embodiment, the gap of the air passage 15-4 formed on the outer periphery of the heater 4 among the above air passages is made as small as possible, and the cooling air in the exhaust jacket 14 is adjusted by each heater.
Air passages 15-3 are respectively formed toward the individual heaters 4, 4 so that they can reach the heaters 4, 4.

Next, its operation will be described. Since the point of manually operating the large and small diameter adjusting bolts to push and pull the flexible lip has been described above, the description thereof will be omitted here, and the heating / heating of the stud bolt 5 will be omitted. The expansion and contraction action by cooling will be mainly described.

When the stud bolt 5 is heated, it expands due to thermal expansion and pushes the flexible lip 1'according to the amount of displacement thereof, and the resin discharge port 21
Narrow the lip gap of. Also, when the stud bolt 5 is cooled, it shrinks, and the flexible lip 1'is pulled up by the amount of displacement,
Increase the lip gap of the resin discharge port 21.

Also in the present invention, the automatic adjusting action of the flexible lip 1'is based on the above operation.

However, the present inventors have confirmed that the adjustment time required for this automatic adjustment depends on the cooling rate of the stud bolt 5.

That is, if the stud bolt 5 is cooled quickly,
The time required to adjust the lip gap can be reduced accordingly.

Therefore, in the illustrated embodiment, in order to enhance the cooling capacity on the outer peripheral side of the tubular heater 4 attached to each stud bolt 5, the gap between the outer peripheral surface air passages 15-4 of each heater 4, 4, ... Is made as small as possible. The cooling air velocity on the outer peripheral surface of the heater 4 is increased, and the cooling air from the exhaust jacket 14 is passed through the air passages 15-3 directed to the individual heaters 4, 4, ...
I'm trying to make sure it hits. A heat insulating material 18 is interposed between the die body 1 and the heater 4 to block heat conduction from the die body 1 to the heater 4 to adjust the lip gap.
Although the heat transfer by the die is avoided, an air layer (gap 19) is provided especially between the heat insulating material 18 and the die body 1 to influence the heat conduction from the die body 1 when the stud bolt 5 is cooled. To prevent it.

(Effect of the Invention) As described in detail above, in the present invention, since the stud bolt for lip adjustment is directly heated by the tubular heater,
The heating speed, that is, the extension displacement speed of the stud bolt is significantly increased as compared with the conventional thermal displacement type lip adjusting device. Further, according to the present invention, when the stud bolt is cooled, the cooling air speed at the outer peripheral surface of each heater is increased. In addition, since the heat effect with the die body is completely cut off by the heat insulating material and the air layer, the cooling rate of the tubular heater, that is, the cooling rate of the stud bolt is increased, and the stud is cooled. The contraction displacement speed of the bolt is also increased, and as a result, the lip adjustment response speed is generally improved, and the lip adjustment time can be shortened differently.

[Brief description of drawings]

FIG. 1 is a side sectional view of a die lip adjusting device for extrusion molding according to a typical embodiment of the present invention, FIG. 2 is a detailed sectional view of B section of FIG. 1, and FIG. 3 is a previously developed extrusion molding. FIG. 4 is a side sectional view of the die lip adjusting device, and FIG. 4 is a detailed view of FIG. Description of main parts of the drawing 1,2… Die body 1 ′… Flexible lip 4… Cylindrical heater 5… Stud bolt 14… Exhaust jacket 15-1,15-2,15-3,15-4… Cooling air passage 21 ... Resin discharge port

Claims (1)

[Scope of utility model registration request] 1. A thermal displacement type lip adjusting device, wherein a plurality of molten resin sheets or film extrusion molding dies are provided in the die lip width direction and the lip gap is adjusted by utilizing thermal expansion and thermal contraction of stud bolts. A cylindrical heater that is fitted onto each of the stud bolts and directly heats the stud bolt; and a minute gap between the heater and the die body, and a space between the heater and the die body. And a cooling jacket which is arranged on the outside air side of the heater and is fixedly mounted on the die body with a minute gap communicating with the heater to the minute gap. A die lip adjusting device for extrusion molding, wherein a cooling air passage communicating with each minute gap formed on the outer periphery of each heater is provided.