JP3119077B2 - Extrusion molding method of weather strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weather strip having a lip portion having a width different depending on a portion, and more particularly to an extrusion molding method for molding the weather strip.

[0002]

2. Description of the Related Art Conventionally, a weather strip is mounted on the periphery of an opening of a vehicle main body of an automobile to seal a space between the opening and a mating member such as a door. As shown in FIG.
The weather strip 31 is formed in a long shape by a known extrusion molding method, and has a sectional shape as shown in FIG.
That is, the weather strip 31 extends to the outside of the vehicle (right side in the figure) from the trim portion 32 attached to the vehicle body and extends from the trim portion 32 to cover a joint portion of the vehicle body. Lip portion 33 for design. The lip portion 33 has a tapered portion 33a that protrudes toward the vehicle inside (the lower side in the figure) at the tip. And
When the weather strip 31 is mounted on the vehicle body,
The tapered portion 33a of the lip portion 33 is in contact with the vehicle body.

Meanwhile, the shape and the like of the mounting portion on the vehicle body side differ depending on the part. For this reason, in recent years, there has been an increasing demand for changing the width W of the lip portion 33 depending on the mounting portion. Therefore, as a technique for responding to this demand, for example, Japanese Patent Laid-Open No. 59-114040
Japanese Unexamined Patent Publication (Kokai) No. H10-26095.

In this technique, unvulcanized rubber is extruded from an extrusion orifice. Then, for example, as described above, when it is desired to partially shorten the width W of the lip portion 33, the shutter is moved to close a part of the extrusion orifice. Due to this partial blockage, the lip 33
Can be shortened at a certain portion. Moreover, according to the above technique, unlike the case where the width of the lip portion 33 is changed by cutting with a cutter,
The generation of excess waste meat (unvulcanized rubber) can be suppressed.

[0005]

By the way, in the above prior art, the shutter on the front face of the extrusion orifice is generally composed of a fixed orifice plate and a movable orifice plate (substantially shutter). .
That is, the movable orifice plate having a predetermined shape moves while sliding with respect to the fixed orifice plate (not shown). Due to this movement, the width W of the lip 33
Is changed.

However, in this case, there is a possibility that unvulcanized rubber may enter a boundary portion (a so-called PL portion) between the movable orifice plate and the fixed orifice plate. In such a case, as shown in FIG. 13, a burr 34 made of unvulcanized rubber is attached to the end of the lip 33.
Is formed, and as a result, the function as the lip portion 33 may not be sufficiently exhibited. In addition, as shown in the drawing, when the burr 34 is located on the design surface side at the time of mounting, there is a possibility that the appearance quality may be significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a lip portion having a different width depending on a portion and a tapered portion at the tip of the lip portion. When molding the weather strip,
It is an object of the present invention to provide a method for extruding a weatherstrip which can sufficiently exert the function of a lip portion and can improve appearance quality.

[0008]

In order to achieve the above-mentioned object, the present invention provides a weather strip having a lip portion having a different width depending on the portion and having a tapered portion at the tip of the lip portion. An extrusion molding method for molding, wherein a portion other than the lip portion is molded by a step of extruding unvulcanized rubber forward from a head and an opening of a main die plate disposed on a front side of the head. Forming a portion corresponding to the lip portion equal to or wider than a maximum width, a fixed orifice plate provided on the front side of the opening, and the fixed orifice also on the front side of the opening. The lip portion is disposed so as to be movable in the width direction of the lip portion so as to slide with respect to the plate, and a boundary portion with the fixed orifice plate is The lip portion is formed by a movable orifice plate having at least a concave portion for substantially forming the tapered portion, the movable lip portion being formed by moving the movable orifice plate. A step of changing the width of the lip portion by causing the trimming plate to be movable in the width direction of the lip portion in a state where the lip portion is in contact with the front surfaces of the fixed orifice plate and the movable orifice plate. Forming a leading edge of the tapered portion into a curved shape by a cutout portion of the trimming plate.

[0009]

According to the above arrangement, the unvulcanized rubber is pushed forward from the head. The unvulcanized rubber is discharged from the opening of the main die plate arranged on the front side of the head, so that the portion other than the lip portion of the weather strip is molded, and the portion corresponding to the lip portion has the maximum width. , Or wider than the maximum width. Next, the concave portion of the movable orifice plate provided on the front side of the opening substantially forms a lip portion having at least a tapered portion, and the movable orifice plate is moved in the width direction of the lip portion, The width of the lip can be changed. The leading edge of the tapered portion is formed into a curved shape by the cutout portion of the trimming plate which is arranged so as to be movable in the width direction of the lip portion in a state where the fixed orifice plate and the movable orifice plate abut on each other. Is done.

Here, when the unvulcanized rubber passes between the movable orifice plate and the fixed orifice plate, there is a possibility that the unvulcanized rubber may enter the boundary between the fixed orifice plate and the movable orifice plate. is there. In such a case, there is a possibility that burrs due to the unvulcanized rubber may be formed on at least the design surface side on the leading edge side of the tapered portion. However, according to the present invention, immediately after that, the notch of the trimming plate causes the leading edge of the tapered portion to be formed into a curved shape, and at this time, the burr disappears at the same time. Therefore, no burr is formed on at least the design surface side of the obtained weather strip.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will now be described with reference to FIGS.
11 will be described. As shown in FIG. 2, a long weather strip 2 is attached to the periphery of the door opening of the vehicle body 1. This weather strip 2 is formed by EPDM (ethylene-propylene-
Diene copolymer rubber) and has almost the same cross-sectional shape except for a part. That is, as shown in FIG. 3, the weather strip 2 has a trim portion 3 having a substantially inverted U-shaped cross section which is fitted to a flange (not shown) of the vehicle body 1.
And a lip portion 4 extending from one end edge of the trim portion 3 to the vehicle outside (the right side in FIG. 3). At the tip of the lip portion 4, a tapered portion 4a protruding toward the inside of the vehicle (the lower side in FIG. 3).
Are integrally formed. When the weather strip 2 is mounted on the vehicle body 1, the thickened portion 4 a of the lip portion 4 comes into contact with the vehicle body 1, and the lip portion 4 covers the joint portion of the vehicle body 1. Has become. In addition, the coating improves the appearance quality when viewed from the outside of the vehicle.

As shown in FIG. 1, in this embodiment, the width W of the lip portion 4 of the weather strip 2 differs depending on the position. This is because the shape of the mounting portion of the vehicle body 1 differs depending on the part. However, in the present embodiment, the tapered portion 4a has a substantially constant width w1 at any part and has substantially the same shape.

Next, a description will be given of an extruder used for manufacturing the weather strip 2 described above. As shown in FIGS. 1 and 8, unvulcanized EPDM (unvulcanized rubber)
Is extruded forward (to the left in FIG. 8) through an extrusion molding device, and is formed into a predetermined shape. That is, the molding device includes a head 5 for pushing out the unvulcanized rubber forward, a main die plate 6 disposed in contact with the front surface of the head 5, and a fixing device disposed in contact with the front surface of the main die plate 6. An orifice plate 7 and a movable orifice plate 8 are provided, and a trimming plate 9 is provided in contact with the front surface of the orifice plate 7 and the movable orifice plate 8. Describing in more detail, the main die plate 6 has an opening 10 for forming a schematic shape of the weather strip 2. The opening 10 has the same shape as the trim portion 3 at a position corresponding to the trim portion 3. The opening 10 is formed so that a lip 4 having a substantially maximum width can be formed at a location corresponding to the lip 4.

The fixed orifice plate 7 is fixed in contact with the front surface of the main die plate 6 and is arranged above the portion of the opening 10 for forming the lip 4. More precisely, the lower surface of the fixed orifice plate 7 is flush with the upper end surface of the portion of the opening 10 for forming the lip 4.

Further, the movable orifice plate 8 is disposed below the fixed orifice plate 7 in a state of contacting the front surface of the main die plate 6. The movable orifice plate 8 is formed along the shape of the lower surface (inside of the vehicle) of the lip portion 4,
A concave portion 11 for forming the tapered portion 4a is formed. The movable orifice plate 8 is arranged in contact with the lower surface of the fixed orifice plate 7 and is slidable in the width direction of the lip portion 4 (the left-right direction in FIG. 1).

At the same time, a trimming plate 9 is arranged in front of the fixed orifice plate 7 and the movable orifice plate 8. As shown in FIG. 4, the trimming plate 9 is provided with the movable orifice plate 8.
Similarly to the above, the lip 4 can be slid in the width direction (the left-right direction in FIG. 1). A curved notch 9a is formed at the tip of the trimming plate 9 so as to form an arc shape at the tip of the tapered portion 4a.

In this embodiment, the head 5 of the molding apparatus is provided with a mechanism for securing a required discharge amount that fluctuates with the movement of the movable orifice plate 8. That is, as shown in FIG. 8, extruders 18 and 19 having screws 16 and 17 for pushing unvulcanized rubber forward are provided on the rear end side (right end side in the figure) of the head 5. . The extruder 1 is provided in the head 5.
A normal part material flow path 20 and a variable part material flow path 21 for leading the unvulcanized rubber from 8 and 19 to the front are formed, and both merge at a tip end (left end in the figure). ing. That is, the normal part material flow path 20 is a flow path mainly for extracting unvulcanized rubber for forming the trim part 3, and the variable part material flow path 21 is mainly a lip part 4.
This is a flow path for molding the. Further, the variable part material flow path 21 is once branched into a steady part material flow path 22 and a branch part material flow path 23 on the way.

In the middle of the material flow passage 23, there is provided a means for adjusting the discharge amount to reliably absorb the fluctuation in the flow rate of the unvulcanized rubber. That is, a cylinder 24 has an opening formed in the flow channel material passage 23, and a piston 25 is provided in the cylinder 24. For this reason, the unvulcanized rubber flowing in the branch part material flow path 23 can be accommodated in the cylinder 24,
The capacity is adjusted according to the movement of the piston 25.

As shown in FIG. 1, in the present embodiment, a driving device 26 for moving the movable orifice plate 8, the trimming plate 9, and the piston 25,
27 and 28 are provided. These driving devices 26-2
Reference numeral 8 is constituted by, for example, a servomotor or the like. Further, in this embodiment, a controller 29 for controlling these driving devices 26 to 28 is provided. The driving of each of the driving devices 26 to 28 is controlled by the controller 29, and the moving amounts of the movable orifice plate 8, the trimming plate 99, the piston 25, and the like are adjusted. However, in the present embodiment, for convenience of explanation, the movable orifice plate 8 and the trimming plate 9 are configured to move substantially integrally.

In this embodiment, one weather strip 2
The relationship between the capacity in the cylinder 24 and the amount of discharge from the opening 10 with respect to the time in one cycle in the case of manufacturing is as shown in FIG. 11, for example. That is, the supply amount of the unvulcanized rubber to the normal part material flow path 20, the steady part material flow path 22, and the branch part material flow path 23 is substantially constant. When the movable orifice plate 8 is moved inward and the opening area for forming the lip portion 4 is reduced, the unvulcanized rubber mainly in the flow path material flow path 23 may become excessive. Therefore, to suppress this, it is necessary to reduce the ejection amount. In such a case, by lowering the piston 25, the capacity in the cylinder 24 increases. When the capacity in the cylinder 24 is increased, the unvulcanized rubber flowing in the branch part material flow path 23 is stored in the cylinder 24, and the amount discharged from the branch part material flow path 23 is reduced. Decrease. Therefore, the opening 1
The discharge amount from 0 will decrease. Therefore, a desired shape can be obtained for the lip portion 4 extruded from the orifice.

On the other hand, when the movable orifice plate 8 is moved outward and the opening area for forming the lip portion 4 is increased, the unvulcanized rubber supplied to the orifice may be insufficient. . To suppress this, it is necessary to increase the discharge amount. In such a case, pushing up the piston 25 reduces the capacity in the cylinder 24.
When the capacity in the cylinder 24 is reduced, in addition to the unvulcanized rubber flowing in the flow dividing material passage 23, the unvulcanized rubber stored in the cylinder 24 is also distributed in the flow dividing material passage. 23. Therefore, the amount discharged from the branch part material flow path 23 increases, and the discharge amount from the opening 10 increases. Accordingly, a desired shape can be obtained for the lip portion 4 extruded from the orifice. However, there is a slight time lag in the change in the discharge amount from the opening 10 with respect to the change in the capacity in the cylinder 24. In this regard, the drive timing of the drive devices 26 to 28 by the controller 29 can be appropriately adjusted.

In this embodiment, as shown in FIG.
At least once per cycle, the setting is made so that the internal capacity of the head 5 is minimized. With this setting, all of the unvulcanized rubber in the cylinder 24 flows out into the branch flow channel 23 at least once in one cycle.

Further, in this embodiment, a manufacturing apparatus for finally manufacturing the weather strip 2 is provided. That is, the manufacturing apparatus is, outside of the molding apparatus,
A vulcanizing device (not shown) for vulcanizing the extruded unvulcanized rubber, a cooling device (not shown) for cooling the vulcanized EPDM, and cutting the EPDM to a predetermined length. A cutting device (not shown) for finally obtaining the weather strip 2 is provided. However, in the present embodiment, since each of these devices uses a known technique, the detailed description thereof is omitted.

Next, the operation (mainly, the molding method) in the production of the weather strip 2 using the production apparatus including the above-described molding apparatus will be described. First, the extruders 18 and 19 are driven to draw out the unvulcanized rubber to the front. Then, the unvulcanized rubber flows in the normal part material flow path 20 and the variable part material flow path 21. The unvulcanized rubber flowing in the normal part material flow path 20 is directly guided to the opening 10 of the main die plate 6. On the other hand, the unvulcanized rubber flowing in the variable part material flow path 21 is in the stationary part material flow path 2
2 and the flow is divided into the material flow passage 23. The unvulcanized rubber diverted to the stationary part material flow path 22 is directly guided to the opening of the main die plate 6. The unvulcanized rubber diverted to the diverter material flow path 23 is supplied to the cylinder 24
Is led to the opening of the main die plate 6.

Here, initially, as shown in FIG. 5, the movable orifice plate 8 and the trimming plate 9 are located at the outermost (rightmost in the figure). The unvulcanized rubber that has flowed through each of the channels 20, 22, and 23 from this state is removed from the opening 10 of the main die plate 6.
Is derived from Then, the unvulcanized rubber extruded from the opening 10 of the main die plate 6 is substantially formed in the approximate shape of the weather strip 2. That is, by this extrusion, the shape of the trim portion 3 is formed, and the lip portion 4 is roughly formed.

Subsequently, the unvulcanized rubber passes between the fixed orifice plate 7 and the movable orifice plate 8 arranged on the front surface of the opening 10 at a portion corresponding to the lip portion 4. With this passage, as shown in FIG. 7 (for convenience, the fixed orifice plate 7 and the movable orifice plate 8 are separated from the trimming plate 9), and the shape of the tapered portion 4a is substantially formed. And the lip width W is determined. At this time, unvulcanized rubber may enter the boundary between the fixed orifice plate 7 and the movable orifice plate 8. In such a case, the burr B of unvulcanized rubber may be formed on the design surface side of the tip edge side of the tapered portion 4a for a moment. However, according to the present embodiment, thereafter, the notch 9a at the tip of the trimming plate 9 forms the tip edge of the tapered portion 4a into a curved shape, and at this time, the burr B disappears at the same time. Therefore, burrs B are not formed on at least the design surface side of the obtained weather strip 2.

During the above-described extrusion, when the controller 29 determines that the timing for changing the width W of the lip portion 4 to a short time has come, the controller 29 operates the driving devices 26 to 28 appropriately. That is, as shown in FIG. 9, the piston 25 is pulled down by the driving device 28. This lowering increases the capacity in the cylinder 24. In such a case, the unvulcanized rubber flowing in the branch part material flow path 23 is stored in the cylinder 24, and the amount of rubber discharged from the branch part material flow path 23 is reduced. Therefore, the discharge amount from the opening 10 decreases. Here, as the retraction speed of the piston 24 increases, the amount of unvulcanized rubber guided into the cylinder 24 per unit time increases, and the flow path 2
The discharge amount (discharge speed) of the rubber from No. 3 decreases.

Then, with a slight time lag, as shown in FIGS. 6 and 9, the movable orifice plate 8 and the trimming plate 9 are moved inward (left in FIG. 6, upward in FIG. 9) by the driving devices 26 and 27. And move. Then, since the movable orifice plate 8 moves inward, the concave portion 11 for forming the tapered portion 4a also moves. For this reason, the position of the portion corresponding to the thickened portion 4a of the unvulcanized rubber moves inward. In addition, since the trimming plate 9 moves inward, the outer portion of the unvulcanized rubber extruded from the opening 10, that is, the lip portion 4.
The molding site corresponding to the leading end of the member also moves inward. At this time, since the movable orifice plate 8 and the trimming plate 9 move continuously in a series of movements, the lip portion 4 is smoothly and continuously narrowed along the length direction. Further, at this time, although the area of the opening between the fixed orifice plate 7 and the movable orifice plate 8 decreases, the discharge amount from the opening 10 also decreases as described above. Therefore, the flow rate of the unvulcanized rubber to be discharged is kept substantially constant.

Conversely, when the controller 29 determines that it is time to change the width W of the lip portion 4 to a longer width so as to return to the original width, the operation reverse to the above is performed. That is, as shown in FIG. 10, the piston 25 is pushed up by the driving device 28. Due to this pushing up, the capacity in the cylinder 24 decreases. In such a case, the unvulcanized rubber in the cylinder 24 flows out into the branch part material flow path 23 in addition to the unvulcanized rubber flowing in the branch part material flow path 23. The amount discharged from the passage 23 increases. Therefore, the discharge amount from the opening 10 increases. Here, as the lifting speed of the piston 24 increases, the amount of plus alpha unvulcanized rubber flowing out of the cylinder 24 per unit time increases, and the rubber is discharged from the branch part material flow path 23 per unit time. The amount (discharge speed) increases.

When the driving devices 26 and 27 are driven with a slight time lag, the movable orifice plate 8 and the trimming plate 9 move outward (to the right in the figure) as a unit, and the lip 4 Are widened smoothly and continuously along the length direction. As described above, the movable orifice plate 8 and the trimming plate 9 integrally move inward or outward, so that the edge portion of the lip portion 4 is appropriately changed inward or outward. The width W of the corresponding portion varies. Then, the unvulcanized rubber is formed into the shape of the weather strip 2.

Thereafter, the unvulcanized rubber molded as described above is supplied to a manufacturing device such as a vulcanizing device, a cooling device, a cutting device and the like. And after the unvulcanized rubber is vulcanized and cooled,
The weatherstrip precursor (weatherstrip 2 before cutting) is cut to a predetermined length. As a result, as described above, the width W differs depending on the region, and the tapered portion 4a at the tip end of both the changing portion and the linear portion always has substantially the same length and shape (appearance). The weather strip 2 is obtained.

As described above, according to this embodiment,
As the unvulcanized rubber passes between the fixed orifice plate 7 and the movable orifice plate 8, the unvulcanized rubber enters the boundary between the two orifices 7 and 8, and the burr B may be formed for a moment. . However, thereafter, the distal end edge of the tapered portion 4a is formed into a curved shape by the peripheral surfaces of the pair of upper and lower trimming plates 9, and at this time, the burrs B disappear at the same time. For this reason, the obtained weather strip 2
Is not formed at least on the design surface side. As a result, the function of the lip portion 4 can be sufficiently exhibited, and the appearance quality can be improved.

In the present embodiment, the width W of the lip is adjusted by moving the movable orifice plate 8. Therefore, unlike the case where the width of the lip portion is changed by cutting with a cutter, the generation of excess waste meat (unvulcanized rubber) can be suppressed.

Further, in the present embodiment, the head 5 is designed to suppress the fluctuation of the internal pressure of the orifice and the like caused by the movement of the movable orifice plate 8 and to adjust the internal volume of the head 5 to suppress the fluctuation of the flow velocity. Mechanism is provided. That is, first, various material flow paths 20, 22, and 23 are provided in the head 5. For this reason, even if there is a slight change in the internal pressure when the movable orifice plate 8 is moved, the pressure change can be absorbed particularly in the flow path material flow path 23.

In this embodiment, the material flow path 23 of the branching section
Is provided with a cylinder 24 and a piston 25 in the middle, and when it is determined that the timing to change the width W of the lip portion 4 has arrived, the position of the piston 25 is appropriately adjusted and controlled by the controller 29. For this reason, the capacity of the head 5 is adjusted, and even if the area of the opening between the fixed orifice plate 7 and the movable orifice plate 8 fluctuates, the discharge amount is appropriately changed, and the unvulcanized rubber is removed. The flow rate can be kept almost constant. Therefore, it is possible to prevent a problem that the lip portion 4 is deformed due to a sudden and large fluctuation of the flow velocity.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above embodiment, the movable orifice plate 8 and the trimming plate 9 are driven integrally. However, the two 8, 9 are slightly different, for example, a slight time lag is provided in the movement of the two. It is good also as composition which makes a motion.

(2) In the above embodiment, the weather strip 2 is formed by EPDM, but other rubber may be used. Further, in the above-described embodiment, the weather strip 2 attached to the periphery of the door opening of the vehicle body 1 is embodied. However, the weather strip 2 may be embodied in other places. Therefore, the weather strip may have any shape as long as it has a lip portion, and may have, for example, a hollow seal lip.

(3) In the above embodiment, two extruders 1
Although the configuration using 8 and 19 is adopted, one extruder may be used. (4) In the above-described embodiment, a configuration is adopted in which a mechanism for suppressing the pressure fluctuation and suppressing the flow velocity fluctuation by adjusting the internal capacity of the head 5 is adopted. In the case where there is no such mechanism, a configuration without the above-described mechanism may be adopted.

[0039]

[Appendix] The technical ideas which are not described in each claim of the claims but can be grasped from the above embodiments are described below together with their effects.

(A) The extrusion molding method according to claim 1, wherein the movable orifice plate (8) is moved to form a weatherstrip (2) having a different cross-sectional shape depending on a portion every cycle. Wherein the unvulcanized rubber flows inside the plurality of flow paths (20, 22, 23) inside the head (5) and almost merges at the opening (10). In addition, at least one of the flow paths (23) can directly receive a pressure fluctuation due to the movement of the movable orifice plate (8). With such a configuration, when the movable orifice plate moves and the opening area of the unvulcanized rubber fluctuates, at least one of the flow paths may receive a pressure fluctuation in the head. The pressure fluctuation propagates to the base end of the flow path. Therefore, if the pressure fluctuation is minute, the pressure fluctuation is sufficiently attenuated during the propagation, and the pressure fluctuation is substantially suppressed. For this reason, the flow rate of the unvulcanized rubber at the time of discharge does not fluctuate so much. As a result, the shape is further stabilized, so that a weather strip having a desired shape can be reliably obtained.

(B) The method for extruding a weather strip according to the above (a), wherein the head (5)
In the middle of the flow path (23) of the unvulcanized rubber formed in the inside,
A head capacity adjusting mechanism (24, 25) for adjusting the capacity of the unvulcanized rubber in the head (5) is provided, and the opening (10) is controlled by the head capacity adjusting mechanism (24, 25). The discharge amount of unvulcanized rubber is adjusted every cycle. With this configuration, even if the opening area of the discharge portion fluctuates due to the movement of the movable orifice plate, it is possible to adjust the internal capacity of the head and thus the discharge amount in accordance with the fluctuation. Therefore, it is possible to substantially suppress the fluctuation of the pressure in the head and the fluctuation of the flow velocity of the unvulcanized rubber at the time of discharge. (C) In the method for extruding a weatherstrip described in the above supplementary note (b), the head capacity adjusting mechanism may include a cylinder (24) and a piston (slidably disposed in the cylinder (24)). 25). With such a configuration, the capacity of the unvulcanized rubber in the head can be easily adjusted by sliding the piston in the cylinder.

[0042]

As described above in detail, according to the method for extruding a weather strip of the present invention, a lip portion having a different width depending on a portion is provided, and a tip portion of the lip portion has a tapered portion. When forming a weather strip, the function of the lip portion can be sufficiently exerted, and furthermore, an excellent effect that the appearance quality can be improved can be achieved.

[Brief description of the drawings]

FIG. 1 is a partial perspective view showing a main part of a molding apparatus in a method for extruding a weather strip according to an embodiment of the present invention.

FIG. 2 is a side view of the vehicle body showing a mounting position of a weather strip in one embodiment.

FIG. 3 is a partial perspective view showing a weather strip in one embodiment.

FIG. 4 is a front view showing a main part of an apparatus for extruding a weather strip in one embodiment.

FIG. 5 is a partial front sectional view showing an extrusion molding apparatus according to one embodiment.

FIG. 6 is a partial front sectional view showing a moving state of a movable orifice plate and a trimming plate of the extrusion molding apparatus in one embodiment.

FIG. 7 is a partial perspective view illustrating an operation when forming a weather strip in the extrusion forming method according to one embodiment.

FIG. 8 is a system diagram showing a mechanism or the like for adjusting a capacity in a head in the extrusion molding method in one embodiment.

FIG. 9 is a system diagram showing a mechanism and the like for adjusting the capacity in the head in the extrusion molding method in one embodiment.

FIG. 10 is a system diagram showing an operation of a mechanism or the like for adjusting a capacity in a head in the extrusion molding method in one embodiment.

FIG. 11 is a timing chart showing a relationship between a capacity in a cylinder and a discharge amount from an opening with respect to time in one cycle in one embodiment.

FIG. 12 is a cross-sectional view showing a weather strip according to the related art.

FIG. 13 is a cross-sectional view of a weather strip illustrating a problem in the related art.

[Explanation of symbols]

2 ... weather strip, 4 ... lip part, 4a ... taper part, 5 ... head, 6 ... main die plate, 7 ... fixed orifice plate, 8 ... movable orifice plate, 9 ...
Trimming plate, 10 ... opening, 11 ... recess, W ...
width.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-128721 (JP, A) JP-A-2-34450 (JP, A) JP-A-52-4456 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B29C 47/00-47/96 B60R 13/06

Claims (1)

(57) [Claims] 1. A weatherstrip (2) having a lip portion (4) having a width (W) that differs depending on a portion and having a tapered portion (4a) at the tip of the lip portion (4). Extruding unvulcanized rubber forward from a head (5); and an opening (10) in a main die plate (6) disposed in front of the head (5). Forming a portion other than the lip portion (4), and forming a portion corresponding to the lip portion (4) equal to or wider than a maximum width; and a front side of the opening (10). And the lip portion (4) in the width (W) direction so as to slide with respect to the fixed orifice plate (7) at the front side of the opening (10). Moveable to And a boundary portion between the fixed orifice plate (7) and the fixed orifice plate (7) is located at least on a design surface side of a front end side of the tapered portion (4a), and substantially forms at least the tapered portion (4a). The lip portion (4) is formed by a movable orifice plate (8) having a concave portion (11), and the lip portion (4) is formed by moving the movable orifice plate.
Changing the width of the lip portion (4) in the width (W) direction of the lip portion (4) in a state of contacting the front surfaces of the fixed orifice plate (7) and the movable orifice plate (8). Using the trimming plate (9), the notch (9a) of the trimming plate (9) allows the tapered portion (4) to be formed.
a) forming the tip edge into a curved shape according to (a).