JP3536371B2 - Apparatus and method for manufacturing extruded molded products with variable cross-section - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for producing a profile extrusion molded article having a variable cross sectional shape.

[0002]

2. Description of the Related Art Generally, profile extrusion molding is for obtaining a continuous molded product having the same cross-sectional shape. For example, automobile window moldings, side protect moldings, belt moldings, etc. are manufactured by this method. However, the same cross-sectional shape is not preferable for some products. For example, a windmill for automobiles is provided with a rain garter on the wind side so that the water droplets scattered by the wiper do not splash to the side glass, and on the upper part of the wind there is no rain garter so that the water droplets can be easily discharged to the outside. .

As a method for continuously obtaining such a product whose cross-sectional shape changes, there is a method described in Japanese Patent Laid-Open No. 4 338523. FIG. 7 is a schematic sectional view of extrusion molding showing this method. This is a conventional example of extrusion molding of an automobile window molding as shown in FIG. 8, which includes a main body portion 31 mounted in a gap between the vehicle body panel for fixing the automobile window to the vehicle body panel, and rainwater as described above. The shape change part 32 is partially formed in the main body 31 to prevent discharge or splashing. In FIG. 7, reference numeral 4
Reference numeral 1 is a die, and 42 is a resin outlet of the die, and a main body portion outlet 43 and a shape changing portion outlet 44 are integrally formed. Further, reference numeral 45 is a resin flow path of the resin material A forming the main body portion 31, and 46 is a resin material B forming the shape changing portion 32.
Resin flow path 47, a bypass flow path 47 for the excess resin material B1 formed in the flow path 46 of the resin material B forming the shape change portion 32, and a discharge port 49. Reference numeral 50 is an opening / closing member for opening / closing the shape changing portion outlet 44 of the resin outlet 42 of the die. Reference numeral 61 is an extruder for the resin material A forming the main body portion 31, and 62 is an extruder for the resin material B forming the shape changing portion 32.
It is supplied to the respective resin outlets 43 and 44 of the die outlet 42 via the nozzles 5 and 46.

An opening / closing member 50 provided at the outlet 44 of the shape changing portion
When the valve 44 moves forward and closes the outlet 44, the opening / closing member 50 simultaneously opens the discharge port 49 of the excess resin material and opens the bypass 4
Since 7 is opened, the surplus resin material B1 of the resin material B flowing through the flow path 46 is discharged to the outside from the discharge port 49 via the bypass flow path 47.

As described above, in the conventional method for manufacturing a profile extrusion molded product having a changed cross-sectional shape, the cross-sectional shape is changed by opening and closing the opening / closing member, and the surplus resin generated due to the change in the cross-sectional shape is bypassed. It was discharged from the channel.

[0006]

However, when it is attempted to manufacture a profile extrusion molded product whose cross-sectional shape changes by the above-mentioned method, a surplus resin is always generated, and this resin must be discarded. For this reason, the yield of the material was poor and the cost was high.

Therefore, it is a technical object of the present invention to improve the material yield and to reduce the cost by manufacturing a profile extrusion molded product whose cross-sectional shape changes by a method that does not generate excess resin. It is a thing.

[0008]

The technical means (hereinafter referred to as the first technical means) taken in the invention of claim 1 to solve the above-mentioned problems are molded with the same sectional shape.
Has a main body part and a shape changing part whose cross-sectional shape changes.
An apparatus for manufacturing a profile extrusion molded article, the manufacturing apparatus comprising:
A first extruder for extruding the resin forming the body;
Second Extruder for Extruding Resin Forming Condition Change Portion
And an extrusion die with a main body outlet and a shape change portion outlet formed
And an opening / closing means for opening / closing a part of the outlet flow path of the extrusion die, a driving means for driving the opening / closing means, and driving the driving means and controlling the screw rotation speed of the second extruder. And a control means, wherein the control means is
When molding a portion where the cross-section of the extrusion-molded product is gradually reduced, the closing operation of the opening / closing means is started by driving the driving means, and a part of the outlet flow path of the extrusion die is gradually increased. When the screw speed of the second extruder is gradually decreased while closing, the screw speed of the second extruder is set to a constant low speed or at the time of molding a portion having a small cross section of the extrusion-molded product. When the section of the extrusion-molded product whose cross-section is gradually increased is to be stopped, the opening operation of the opening / closing means is started by driving the driving means to start the exit flow path of the extrusion die. The screw rotation speed of the second extruder is gradually increased, and the screw rotation speed of the second extruder is kept constant when molding a portion of the extrusion-molded product having a large cross section. high speed Controlled so as to rolling, and extrusion
The cross section of the extruded product gradually increases from the large cross section of the molded product.
When moving to the area where the
For a certain period after starting the operation to reduce the screw speed of the engine
After a gap, start the closing operation of the opening / closing means,
Extrusion molding from the part where the cross section of the molded product gradually decreases
When moving to a portion where the cross section of the shaped product is small, the second push
For a certain period after the completion of the operation to reduce the screw speed of the engine
After leaving a gap, complete the closing operation of the opening / closing means, and push
The cross section of the extruded product gradually increases from the small cross section of the molded product.
When moving to larger becomes not rather portion, the second press
For a certain period after the start of the operation of increasing the screw speed of the engine
After opening a gap, start the opening operation of the opening and closing means, and push
Extrusion molding from the part where the cross section of the molded product gradually increases
When moving to a portion with a large cross section of the shaped article, the second push
For a certain period after the completion of the operation to increase the screw speed of the engine
After leaving a gap, complete the opening operation of the opening / closing means.
The apparatus for producing a profile extrusion molding is characterized in that

[0009]

The invention of claim 2 (hereinafter, referred to as the second technique)
(Referred to as "expensive means"), the constant intervals are extrusion molding conditions,
It can be changed sequentially depending on the resin material and the shape of the extruded product.
It has a feature.

[0011]

In order to solve the above technical problem, a third aspect of the present invention is provided.
The technical means taken in the invention (hereinafter referred to as the third technical means) is an opening / closing means for opening / closing a part of the outlet flow path of the extrusion die, a driving means for driving the opening / closing means, and the driving means. It has a control means for driving the means and controlling the screw rotation speed of the extruder, and a detection means for detecting the screw rotation speed of the extruder, wherein the control means is such that the cross section of the extrusion-molded product becomes gradually smaller. The screw rotation speed of the extruder is gradually reduced when molding the moving part, and the driving means is driven when the screw rotation speed detected by the detection means reaches the closing start set rotation speed. When the closing operation of the opening / closing means is started, and the screw speed of the extruder is rotated at a constant low speed or stopped when molding a portion of the extrusion molded product having a small cross section, the cross section of the extrusion molded product is gradually changed. When molding the increasing part, gradually increase the screw rotation speed of the extruder, and drive the driving means when the screw rotation speed detected by the detection means reaches the opening start set rotation speed. The opening operation of the opening / closing means is started to control the screw rotation speed of the extruder to a constant high speed when molding a portion of the extrusion molded article having a large cross section. This is an apparatus for producing a profile extrusion molded article.

In order to solve the above technical problem, a fourth aspect is provided.
The technical means taken in the invention (hereinafter, referred to as a fourth technical means) is an opening / closing means for opening / closing a part of an outlet flow path of an extrusion die, a driving means for driving the opening / closing means, and the driving means. It has a control means for driving the means and controlling the screw rotation speed of the extruder, and a detection means for detecting the screw rotation speed of the extruder, wherein the control means is such that the cross section of the extrusion-molded product becomes gradually smaller. The screw rotation speed of the extruder is gradually reduced when molding the moving part, and the driving means is driven when the screw rotation speed detected by the detection means reaches the closing start set rotation speed. When the closing operation of the opening / closing means is started, and the screw speed of the extruder is rotated at a constant low speed or stopped when molding a portion of the extrusion molded product having a small cross section, the cross section of the extrusion molded product is gradually changed. When molding the increasing part, gradually increase the screw rotation speed of the extruder, and drive the driving means when the screw rotation speed detected by the detection means reaches the opening start set rotation speed. The opening operation of the opening / closing means is started to control the screw rotation speed of the extruder to a constant high speed when molding a portion of the extrusion molded article having a large cross section. The method for producing a profile extrusion molded article is as follows.

[0014]

According to the first technical means, the screw rotation speed of the extruder is controlled according to the movement of the opening / closing means to close or open, and when the portion having a small cross section of the extrusion molded product is molded. The resin is extruded at a high screw rotation speed when the screw rotation speed is low or stopped and a portion having a large cross section of the extruded product is being molded.
Therefore, it is possible to always supply the resin in an amount commensurate with the size of the cross-section of the extrusion-molded product, and no excess resin is generated as in the conventional case. Therefore, the yield of the resin material can be improved and the cost can be reduced. Further, the control means is
The cross section of the extruded product gradually increases from the large cross section of the molded product.
When moving to the smaller part, the extruder screen
After starting the deceleration operation of Liu rotation speed,
After that, the closing operation of the opening / closing means is started and the extruded product is disconnected.
Cross section of extruded product from the part where the surface gradually becomes smaller
Screw rotation of the extruder when moving to a smaller area
After a certain number of deceleration operations are completed
The closing operation of the closing means is completed, and the cross section of the extruded product is small.
The part where the cross section of the extruded product gradually increases from the part
When moving to the minute, the screw speed of the extruder is increased.
Opening of the opening / closing means after a certain interval after starting the work
As the extrusion started, the cross section of the extruded product gradually increased.
When moving from a hollow part to a part with a large cross section of the extrusion
In addition, there is a mark that the screw speed increase operation of the extruder is completed.
After a certain time interval, bureaucrats should open the opening / closing means.
I made it possible. As a result, the cross-sectional shape of the extruded product
As it changes, the viscoelastic properties of the resin and the screw and die
Due to the delay in resin response caused by the distance from the outlet
Prevents the product surface from rising and becoming defective.
To do.

[0015]

According to the second technical means, the first
The constant intervals in the above technical means are sequentially changed depending on the extrusion molding condition, the resin material, and the shape of the extrusion molded product. As a result, the method and apparatus according to the present invention can be used under various resin materials and molding conditions, and the material yield can be improved and the cost can be reduced for more products.

According to the third and fourth technical means, when molding the portion where the extrusion cross section changes, first, the screw rotation control means reduces or increases the screw rotation. Although the screw rotation speed is always detected by the detection means, when the screw rotation speed reaches the closing or opening set rotation speed, the control means drives the driving means to start closing or opening of the opening / closing means. this is,
In the first technical means, instead of driving the driving means after a certain period of time from the start of the screw increasing / decreasing operation, when the screw rotation speed reaches a certain number of rotations after the screw increasing / decreasing operation starts, the driving means Is to drive. As a result, when the cross-sectional shape of the extrusion-molded product changes, swelling occurs on the product surface due to the resin's viscoelastic characteristics and the response delay of the resin caused by the distance between the screw and the die outlet, resulting in a defective product. Prevent.

[0018]

EXAMPLES The present invention will be described below with reference to examples.

FIG. 1 and FIG. 2 are cross-sectional shapes of extruded products molded in the embodiment of the present invention. The molded product includes a body portion 23 and a shape changing portion 24. The body portion 23 is always formed with the same cross-sectional shape, but the shape changing portion 24 changes the cross-sectional shape. 1 shows the case where the cross section of the shape changing portion 24 is large, and FIG. 2 shows the state when the cross section of the shape changing portion 24 is small.

FIG. 3 is a schematic sectional view of extrusion molding showing an embodiment of the present invention. In FIG. 3, reference numeral 1 is a die, 2
Is an outlet of the die, and the body portion outlet 3 and the shape changing portion outlet 4 are integrally formed. Reference numeral 5 is a resin flow path of the resin material A forming the body portion 23 in FIG. 1 or 2, and 6 is a resin flow path of the resin material B forming the shape changing portion 24 in FIG. 1 or 2. Reference numeral 7 is an opening / closing member that opens / closes the shape changing portion outlet 4 of the resin outlet 2 of the die. The opening / closing member 7 is rotatably held by a holding plate 10 that holds the opening / closing member, and the holding plate 10 is fixed to the die 1 by bolts 11. Reference numeral 8 is an extruder for the resin material A forming the main body portion 23, and 9 is an extruder for the resin material B forming the shape changing portion 24, which passes through the respective resin flow paths 5 and 6 and then exits the die. 2 is supplied to each of the resin outlets 3 and 4. The driving device 25 for opening and closing the opening / closing member 7 is electrically connected to the control device 26, and the driving device is driven by a signal from the control device 26 to open / close the opening / closing member. The control device 26 is also electrically connected to the drive motor 27 of the extruder 9, and the screw rotation speed of the extruder 9 is controlled to be low rotation or high rotation by a signal from the control device 26. In addition, the control device 2
6 can simultaneously control the drive device 26 and the drive motor 27 of the extruder 9. For example, a signal can be sent to the drive device 25 to open the opening / closing member, or at the same time or after a predetermined time, a signal can be sent to the drive motor 27 of the extruder 9 to control the screw rotation speed to a high rotation speed. In the embodiment, an air cylinder is used as a driving device.

4 and 5 are views of the extrusion die as viewed from the front. A lever pin 12 is projectingly provided on the opening / closing member 7. Reference numeral 13 is a lever having a lever pin insertion hole 18 formed in the upper portion thereof, and the lever pin 1 is inserted into the lever pin insertion hole 18.
2 is rotatably inserted. A screw hole 19 is provided in the lower portion of the lever 13, and the rod 14 of the cylinder 15 is screwed into the screw hole 19 by screwing the tip thereof. Further, the cylinder 15 has a support member 2 at a lower portion thereof.
It is supported by 0 so as to be rotatable around the pin 21 of the supporting member 20. The support member is connected to the holding plate 10 via the intermediate member 22, and supports the cylinder 15 so that the cylinder 15 does not move up and down. In such a structure, when the rod 14 and the lever 13 are raised, the opening / closing member 7 moves in a direction of closing the shape changing portion outlet 4 of the die outlet 2. Then, the stopper pin 16 provided on the opening / closing member 7 contacts the stopper block 17 to complete the closing operation. The state at this time is shown in FIG.
Is indicated by. When the lever 13 and the rod 14 descend, the opening / closing member 7 moves in the direction of opening the shape changing portion outlet 4. Then, after completely opening the shape change portion outlet 4,
Depending on the stroke of the cylinder, lever 13 and rod 14
Stops falling and completes the opening operation. The state at this time is shown in FIG.

In the embodiment of the present invention having such a configuration, when the cross section (the cross section shown in FIG. 1) in which the shape changing portion 24 is large, the opening / closing member 7 is opened and the shape changing portion is formed. The screw rotation speed of the extruder 9 for the resin material B for molding is high. The opening / closing member 7 is gradually closed for the portion where the shape change portion is gradually reduced, and the screw rotation speed of the extruder 9 is also gradually reduced. When the cross-section (the cross-section shown in FIG. 2) when the shape change portion is small is formed, the opening / closing member 7 has completed the closing operation and the screw rotation speed is low. For the part where the shape change part gradually increases,
The opening / closing member 7 is gradually opened, and the screw rotation speed is gradually increased. The opening operation of the opening / closing member 7 is completed,
When the screw rotation speed also becomes high, a portion with a large shape change portion is molded again. By repeating the above-mentioned operation, it is possible to continuously obtain a profile extrusion-molded product whose cross-sectional shape changes.

Next, a method of controlling the opening / closing member and the screw rotation speed at the portion where the cross section gradually changes will be described.

In FIG. 6, the horizontal axis represents time, the upper half of the vertical axis represents the screw rotation speed of the extruder of the resin material B forming the shape change portion, and the lower half of the vertical axis represents the opening / closing ratio of the opening / closing member. The bird
6 is a graph showing changes in screw rotation speed and opening / closing member. In this example, the screw rotation speed of the extruder was 9 rpm when the cross section of the shape change portion was large, and the screw rotation speed of the extruder was 1 rpm when the cross section of the shape change portion was small. Further, the method of determining the opening / closing ratio of the opening / closing member is as follows: a is the length of the portion of the rod 16 discharged from the cylinder when the opening / closing member has completed the opening operation (the state of FIG. 1), and the closing operation of the opening / closing member. B is the length of the portion of the rod 16 discharged from the cylinder in the state in which is completed (state of FIG. 2).
If the length of the portion of the rod 16 discharged from the cylinder at that time is c, then it is determined by (ac) / (ab). Therefore, when the open / close member is completely open, the open / close ratio is 1, when the open / close member is completely closed, the open / close ratio is 0, and when the open / close member is operating, the open / close ratio is 0 to 1.
It is a numerical value between. In the graph, the portion A has a large cross section of the shape change portion, the portion B has a gradually smaller cross section, the portion C has a smaller cross section, and the portion D has a larger cross section. The open / close ratio of the open / close member is shown. When the state where the cross section of the shape change portion is large A is changed to the state B where the cross section is gradually reduced, if the start of deceleration of the screw rotation speed and the start of the closing operation of the opening / closing member are simultaneously performed, the resin pressure increases, The surface rises and becomes a defective product. This takes a certain amount of time until the amount of resin corresponding to the screw rotation speed of the extruder is discharged from the outlet of the die due to the distance from the tip of the screw to the outlet of the die and the viscoelastic property of the resin. Therefore, on the display, even if the screw rotation speed is decreased, there is a time delay in actually discharging the resin amount corresponding to the screw rotation speed from the die outlet. From this, it is expected that during the deceleration operation of the screw of the extruder, more resin is discharged from the die outlet than the resin amount corresponding to the screw rotation speed on the display.

On the other hand, the opening / closing member gradually closes the outlet simultaneously with the start of the closing operation. Therefore, during the closing operation of the opening / closing member, the amount of resin with respect to the cross-sectional area of the outlet increases, and the resin that is forcibly extruded to a high pressure releases the pressure at the moment when it exits from the die, causing swelling. Therefore, in order to obtain a better product, the closing operation of the opening / closing member is controlled after a short time interval (hereinafter referred to as a lap time a) after the deceleration of the screw rotation speed is started. There is a need. In addition, when the state where the cross section is gradually reduced is changed from the state B where the cross section is small to the state where the cross section is small, when the screw rotation speed reaches the set low rotation speed and the closing operation of the opening / closing member is completed at the same time, Similarly, the product surface rises and becomes a defective product. As with the above-mentioned cause, it takes a little time for the resin flow rate according to the screw rotation speed to be discharged from the die outlet, and until then, more resin than the screw rotation speed has been discharged from the die outlet. The discharge amount of the resin when the closing operation of the opening / closing member is completed is larger than the discharge amount according to the screw rotation speed on the display. For this reason, the amount of resin with respect to the cross-sectional area of the outlet increases, and the product surface is raised, resulting in a defective product. Therefore, after the screw rotation speed reaches the set low rotation speed, a certain time interval (hereinafter, referred to as a lap time b) is set, and then the closing operation of the opening / closing member is controlled to be completed, so that the product surface rises. It can be prevented. Due to the same reason, when the state C where the cross section is small is changed to the state D where the cross section is gradually increased, and when the state D is changed from the state D where the cross section is gradually increased to the state A where the cross section is large The amount is delayed until it reaches the discharge amount according to the screw rotation speed on the display.
In this case, since the screw is in the accelerating operation, the increase in the discharge amount of the resin is delayed, and the product surface is deficient. Therefore,
When shifting from the state C to the state D, a certain time interval (hereinafter, referred to as a lap time c) is required between the start of the screw rotation speed increase and the start of the opening operation of the opening / closing member,
Also during the transition from the state D to the state A, there is a time interval (hereinafter referred to as a lap time d) between when the screw rotation speed reaches the set high rotation speed and when the opening / closing member completes the opening operation. It is necessary to provide.

By controlling the lap times a, b, c and d as described above, it is possible to obtain a good-profile extrusion-molded product whose cross-sectional shape changes. For the lap times a and c, a timer that operates from the moment of deceleration and acceleration of the screw rotation speed is provided, and after the set time has elapsed, the closing and opening operations of the opening / closing member may be started. However, the lap times b and d are
In addition to the lap times a and c set by the above-described method, the screw rotation speed, the time required from the start of the closing and opening operations of the opening / closing member to the completion thereof, and the deceleration of the screw rotation speed and the completion of the acceleration operation are completed. The time required to do so is necessary.

In this example, various conditions were changed and experiments were conducted to search for conditions for obtaining an optimum product. As a result, the optimum lap time is as follows: lap time a: 2.0 to 2.5 seconds lap time b: 1.5 to 2.5 seconds lap time c: 1.0 to 2.0 seconds lap The result of time d: 0.5 to 1.5 seconds was obtained. However, this result shows that the screw rotation speed when forming a large cross section is 9 rpm, the screw rotation speed when forming a small cross section is 1 rpm, and the line speed is 1.5 m / min. Is the case. Further, the lap time seems to affect the resin material, the shape of the molded product, and the extrusion molding condition, so it should be sequentially set for a certain material, a certain product, and a certain condition. However, by setting the wrap time by this method, it was possible to obtain a good quality product, so it is possible to manufacture a profile extrusion molded product whose cross-sectional shape changes without discarding excess resin, and to improve the material yield. It is possible to improve the cost and reduce the cost.

[0028]

The invention of claim 1 has the following effects.

In the production of a profile extrusion molding with a variable cross section, the screw rotation speed of the extruder is controlled according to the movement of the opening / closing means to close or open, and a small cross section of the extrusion molding is being molded. Has a low screw rotation speed or is stopped, and when molding a portion of the extrusion-molded article having a large cross section, the resin is extruded at a high screw rotation speed. Therefore, it is possible to reduce the waste resin, improve the yield of the resin material, and reduce the product cost by eliminating the discharge of the excess resin from the bypass as in the conventional case. In addition, the section gradually increases from the large section.
When moving to a smaller section, disconnect from a section with a smaller cross section.
When moving to a part where the surface gradually increases,
At the start of deceleration and acceleration of the screw speed of the extruder
After a certain period of time from
Changes from a small part to a part where the cross-section gradually increases
The cross section gradually decreases from the large cross section
When moving to the
-Opening and closing after a certain period of time from the completion of deceleration and acceleration
Control was performed to complete the opening / closing operation of the member. this
Causes the distance between the screw and the die outlet and the viscosity of the resin.
Product table generated due to delayed response of resin due to elastic characteristics
Good quality products that prevent surface swells and defects such as lack of meat
Can be provided.

[0030]

[0031]

The invention of claim 2 has the following effects.

The fixed time in the first aspect of the invention is influenced by the resin material, molding conditions, and the shape of the product.
Therefore, the present invention can be used in a wide variety of products by sequentially changing this fixed time and setting a fixed time suitable for each resin material, molding condition, and product shape, further improving the material yield and reducing the product cost. Be promoted.

The inventions of claims 3 and 4 have the following effects.

Instead of the fixed time in the first aspect of the present invention, the drive means is driven when the screw rotation speed reaches a certain rotation speed after the increase / decrease of the screw rotation is started.

By adopting such a structure, it is possible to manufacture a profile extrusion molded product in which the cross-sectional shape is changed without discharging the excess resin from the bypass and causing no bulge on the product surface. Therefore, the amount of waste resin can be reduced, the material yield can be improved, and a high quality product can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional shape in the case where the shape-changed portion of the extrusion-molded product according to the present embodiment has a large cross-section.

FIG. 2 is a cross-sectional shape in the case where the cross-section of the shape-changed portion of the extrusion-molded product according to the present embodiment is small.

FIG. 3 is a schematic view of extrusion molding according to the present embodiment.

FIG. 4 is a front view of the vicinity of a die of an extrusion molding apparatus when a cross section of a shape change portion of an extrusion molded article according to the present embodiment is large when forming the cross section.

FIG. 5 is a front view of the vicinity of a die of an extrusion molding apparatus when a cross section of a shape change portion of an extrusion molded article according to this example is small.

FIG. 6 is a diagram showing a method for controlling an opening / closing member for extrusion molding and a screw rotation speed of an extruder according to the present embodiment.

FIG. 7 is a schematic view of extrusion molding according to the prior art.

FIG. 8 is a cross-sectional shape of an extrusion molded article according to the related art.

[Explanation of symbols]

1 die 2 dice exit 3 Dice body section exit 4 Die shape change section exit 5 Body resin flow path 6 Shape change part resin flow path 7 Opening / closing member 8 Extruder for resin material forming main body 9 Extruder for resin material forming shape change part 10 holding plate 11 Volts 12 lever pins 13 lever 14 rod 15 cylinders 16 Stopper pin 17 Stopper block 18 Lever pin insertion hole 19 screw holes 20 Support member 21 pin 22 Intermediate member 23 Body 24 Shape change part 25 Drive 26 Control device 27 drive motor

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-6-71730 (JP, A) International publication 95/006557 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (4)

(57) [Claims] 1. A main body formed with the same cross-sectional shape and a cut
Profile-extruded product having a shape-changed portion whose surface shape changes
A manufacturing apparatus, the manufacturing apparatus, first for extruding a resin for forming the body portion
1 extruder and for extruding the resin forming the shape change part
2nd extruder, main body outlet and shape change portion outlet are formed
Extrusion die, opening / closing means for opening / closing a part of the outlet flow path of the extrusion die, driving means for driving the opening / closing means, and screw rotation speed of the second extruder for driving the driving means. And a control unit for controlling the closing operation of the opening / closing unit by driving the driving unit when molding a portion where the cross-section of the extrusion-molded product is gradually reduced. wherein with starting to gradually close the part of the outlet channel of the extrusion die second
The extruder gradually reducing the screw rotation speed of, when forming a small cross-section portion of the extrudate first
The screw rotation speed of the extruder No. 2 is kept at a constant low rotation speed or stopped, and the opening / closing means is driven by driving the driving means when molding a portion where the cross section of the extrusion molded product gradually increases. To gradually open a part of the outlet flow path of the extrusion die and gradually increase the screw rotation speed of the second extruder to form a large cross section of the extrusion molded product. said when the first
The screw rotation speed of the extruder of No. 2 is controlled to a constant high-speed rotation, and the cross section of the extrusion molded product is changed from the large cross section of the extrusion molded product.
When shifting to a gradually decreasing part, the second
After starting the operation of decreasing the screw speed of the extruder of
After a certain interval, the closing operation of the opening / closing means is started, and the extrusion molded article is pushed from a portion where the cross section gradually becomes smaller.
When the molded article moves to a small cross section, the second
After the screw speed reduction of the extruder is completed,
After a certain interval, the closing operation of the opening / closing means is completed, and the cross section of the extrusion molded product starts from the small cross section of the extrusion molded product.
When shifting to the gradually increasing part, the second
After the start of the operation of increasing the screw speed of the extruder
The opening operation of the opening / closing means is started after a certain interval, and the extruded product is pushed from a portion where the cross section gradually increases.
When the molded article moves to a large section, the second
After the operation of increasing the screw speed of the extruder is completed,
The opening operation of the opening / closing means is completed after a fixed interval.
An apparatus for manufacturing a profile extrusion molded article, which is characterized by being controlled as described above . 2. The manufacturing apparatus according to claim 1, wherein the fixed interval is sequentially changed according to extrusion molding conditions, resin material, and extrusion molded product shape. 3. An opening / closing means for opening / closing a part of the outlet flow path of the extrusion die, a driving means for driving the opening / closing means, and a control means for driving the driving means and controlling the screw rotation speed of the extruder. The detecting means for detecting the screw rotation speed of the extruder is provided, and the control means gradually changes the screw rotation speed of the extruder when forming a portion where the cross section of the extrusion-molded product is gradually reduced. When the screw rotation speed detected by the detection means reaches the closing start set rotation speed, the driving means is driven to start the closing operation of the opening / closing means, and the portion of the extrusion-molded product having a small cross section When molding the extruder, the screw speed of the extruder should be kept at a constant low speed or stopped, and when molding the part where the cross section of the extruded product gradually increases, the screw of the extruder The rotation speed is gradually increased, and when the screw rotation speed detected by the detection means reaches the opening start setting rotation speed, the driving means is driven to start the opening operation of the opening / closing means to An apparatus for producing a profile extrusion molded product having a variable cross section, which is characterized by controlling the screw rotation speed of an extruder to a constant high speed when molding a portion having a large cross section. 4. An opening / closing means for opening / closing a part of the outlet flow path of the extrusion die, a driving means for driving the opening / closing means, and a control means for driving the driving means and controlling the screw rotation speed of the extruder. The detecting means for detecting the screw rotation speed of the extruder is provided, and the control means gradually changes the screw rotation speed of the extruder when forming a portion where the cross section of the extrusion-molded product is gradually reduced. When the screw rotation speed detected by the detection means reaches the closing start set rotation speed, the driving means is driven to start the closing operation of the opening / closing means, and the portion of the extrusion-molded product having a small cross section When molding the extruder, the screw speed of the extruder should be kept at a constant low speed or stopped, and when molding the part where the cross section of the extruded product gradually increases, the screw of the extruder The rotation speed is gradually increased, and when the screw rotation speed detected by the detection means reaches the opening start setting rotation speed, the driving means is driven to start the opening operation of the opening / closing means to A method for producing a profile extrusion-molded article having a variable cross section, which comprises controlling a screw rotation speed of an extruder so as to keep a constant high speed when molding a portion having a large cross section.