JPH0442175B2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an extruder head.

Conventionally, the cross-sectional shape of a molded material extruded from an extruder, such as tread rubber, is changed depending on the type of tire, and this cross-sectional shape is changed by replacing the mouthpiece of the die of the extruder. In order to replace this cap in a short time, various devices have been proposed in the past.
The one described in Japanese Patent No. 139527 is known. However, in all of these devices, when replacing the die, the operation of the heating roll and extruder must be stopped. For this reason, when the operation is restarted, the operating conditions such as the temperature, hardness, and extrusion speed of the rubber in the extruder become unstable, and as a result, the molded material extruded during the period until the operating conditions stabilize to steady values There are problems with quality such as dimensional accuracy, and there are cases where the product has no choice but to be discarded.

This invention was made in view of the above-mentioned problems, and its purpose is to provide an extruder head that can extrude a molded material continuously and with a constant cross-sectional shape regardless of the change of the nozzle. There is.

This purpose consists of a head body, a fixing block provided in the head body and having a bypass recess formed on one side, and a fixing block that is replaceably attached to the head body on one side of the fixing block and has a bypass recess formed on one side of the fixing block. a base having a molding recess formed thereon on the other side that contacts the bypass recess and having the same cross-sectional shape as the cross-sectional shape of the molded material; A shutter is slidably engaged with the back surface of the shutter and has an opening formed therein to guide the molding material into the bypass recess or the molding recess. Along with communicating,
When the shutter is moved to one side to a position where the bypass recess is closed by the shutter and the cap is replaced, the opening and the bypass recess communicate with each other, and the molded recess is closed by the shutter. This can be achieved by providing a moving means for moving the shutter to the other side to a position where the shutter is moved.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes an opposed type extruder, from which a molded material such as tread rubber 2 is extruded. The extruder 1 has a head 3 in the center, and a die 4 below the head 3 that defines the cross-sectional shape of the tread rubber 2.
is attached, and the tread rubber 2 extruded through the die 4 is conveyed to the next process by a conveyor 5. The extruder 1 includes a treaded rubber 2.
An A passage 6 for sending the A type rubber forming the width direction both ends of the tread rubber 2 to the die 4, and a B passage 7 for sending the B type rubber constituting the width direction central part of the tread rubber 2 to the die 4 are formed. Class A and B rubbers kneaded by heating rolls (not shown) are supplied to the passages 6 and 7, respectively. The die 4 extends in the front-rear direction and has a holder 8 serving as a substantially prismatic head body as shown in FIG. A horizontal rectangular hole 9 is formed in the center of the holder 8, and a rectangular discharge hole 10 is formed between the rectangular hole 9 and the lower surface of the holder 8. There is a step 1 at the upper part of the inner surface of one side of this discharge hole 10.
1 is formed, and a step 11 is formed on the upper part of the inner surface of the other side.
A bypass protrusion 12 is formed as a fixed block that protrudes toward the front. As shown in FIG. 4, a bypass recess 14 is formed on one side 13 of the bypass protrusion 12, that is, the tip end surface, and the bypass recess 14 has a shape that is almost the same as the cross-sectional shape of the widest tread rubber. At the same time, it extends in the longitudinal direction of the die 4. A step 11 of the holder 8 located on one side of the bypass protrusion 12
A flat plate-shaped cap 15 parallel to the die 4 is attached so as to be slidable in the longitudinal direction shown by arrow C, and this cap 15 can be replaced with a different type of cap by sliding in the longitudinal direction and pulling it out from the holder 8. It is.
A molding recess 17 is formed on the other side surface 16 of this mouthpiece 15, facing the bypass recess 14 and having the same cross-sectional shape as the tread rubber 2 to be extruded, and this molding recess 17 penetrates in the vertical direction. It also extends in the longitudinal direction of the die 4. Further, the other side surface 16 of the cap 15 is in contact with one side surface 13 of the bypass protrusion 12, and as a result, the bypass recess 14 and the molded recess 17 are in communication with each other at their open ends. Referring again to FIG. 1, a support frame 18 is attached to the front surface of the head 3, and a cylinder 19 located on an extension of the die 4 is attached to the support frame 18. The front end of the mouthpiece 15 is detachably connected to the tip of the piston rod 20 of the cylinder 19. Again, in FIGS. 3 and 4, the rectangular hole 9 has a pair of first and second sliders 21 and 2 parallel to the die 4.
2 is slidably housed, and these first and second sliders 21, 22 as a whole are connected to the bypass protrusion 12.
A shutter 23 is provided upstream of the mouthpiece 15 and slidably engages with the bypass protrusion 12 and the back surface of the mouthpiece 15. Inside this shutter 23, there are first and second sliders 2.
A rectangular opening 24 extending parallel to the die 4 is formed between 1 and 22, and this opening 24 penetrates in the vertical direction to bypass the rubber passing through the recess 1.
4 or into the molding recess 17. The width of this opening 24 is larger than both the depth of the bypass recess 14 and the depth of the molding recess 17. Again, in Figures 1 and 2, 25 and 26 are head 3.
The cylinders 25 and 26 are two pairs of moving means attached to the cylinders 25 and 26, and each cylinder 25 and 26 extends perpendicularly to one side surface 13 of the bypass protrusion 12. piston rods 27 of cylinders 25, 26;
The tips of 28 are connected to one end and the other end of the first and second sliders 21 and 22, respectively, as shown in FIG. As a result, cylinders 25, 26
When the sliders 2 and 2 operate synchronously, the first and second sliders 2
1, 22, that is, the shutter 23 is connected to the base 15.
and move integrally on the bypass protrusion 12 perpendicularly to one side 13 of the bypass protrusion 12. Again, in FIG. 3, reference numeral 29 denotes a central slot extending in the longitudinal direction of the die 4 and communicating the upper surface of the holder 8 with the opening 24 of the shutter 23. As shown in FIG. A central insert 30 located upstream of the shutter 23 is slidably housed. Note that since the upper half of FIG. 5 is omitted, only one center insert 30 is shown, but in reality, this center insert 30 is shown in the omitted upper half.
0 and the other central insert is provided at the same distance from the longitudinal center of the die 4.
These pairs of central inserts 30 are spaced apart from each other, so that these central inserts 30
A passage 31 through which the Class B rubber passes is formed between them. Again, in FIG. 1, a support frame 32 is also attached to the rear surface of the head 3, and cylinders 33, 34 parallel to the die 4 are attached to the support frame 18 and this support frame 32. The tips of the piston rods 35, 36 of these cylinders 33, 34 are connected to the one center insert 30 and the other center insert 30, respectively, via connecting plates 37 as shown in FIG. 35,
By protruding or retracting 36 by an equal amount, both central inserts 30 are moved toward and away from each other by an equal amount, and the length of the passageway 31 is changed. center slot 2
An insert recess 38 parallel to the central slot 29 is formed on one side of the insert recess 3.
One end insert 39 is slidably housed in 8 . Note that, like the central insert 30, the other end insert (not shown) is accommodated in this insert recess 38. Each end insert 39 is formed with an inclined recess 40;
Each inclined recess 40 is located on the outer side in the longitudinal direction from the distal end surface of the central insert 30. Also, 41
is a communication port that communicates the inclined recess 40 with the opening 24, and the type A rubber supplied to the inclined recess 40 is guided to the opening 24 through the communication port 41, and then to the opening 24 through the passage 31. B was scared
It joins both ends of the seed rubber. Again, in FIG. 1, the support frames 18, 32 have the cylinders 3
Cylinders 42 and 43 parallel to the cylinders 3 and 34 are attached, and the tips of the piston rods 44 and 45 of these cylinders 42 and 43 are connected to the one and other end inserts 39 through connection plates 46, respectively. The end inserts 39 are attached to the cylinder 4 by an equal amount to the central insert 30.
It moves by the operation of 2 and 43. In FIGS. 3 and 6, reference numeral 47 denotes a supply plate fixed to the upper surface of the holder 8, and this supply plate 47 has an end supply port 48 through which the A-type rubber in the A passage 6 is supplied to the inclined recess 40. A penetrating central supply port 49 for supplying the B-type rubber in the B passage 7 to the passage 31 is formed, and these ends and the central supply port 48,
49 is the end insert 39 and the center insert 30
It extends in the longitudinal direction of the die 4 so that even if it moves, the A and B type rubbers are supplied to the inclined recess 40 and the passage 31.

Next, the operation of one embodiment of the present invention will be explained.

It is now assumed that a treaded rubber 2 having a predetermined cross-sectional shape is being extruded from the extruder 1. At this time, the shutter 23 is moved to one side by the cylinders 25 and 26, and the other end 50 of the opening 24, that is, one end of the second slider 22, is moved to the third and fourth sides.
As shown in the figure, it is located approximately on the other side surface 16 of the base 15. Therefore, the molding recess 17 is formed at the opening 2.
4, the bypass recess 14 is closed by a shutter 23, that is, a second slider 22. As a result, the A and B type rubbers supplied from the heating roll to the A and B passages 6 and 7, respectively, pass through the end supply port 48, the inclined recess 40, the communication port 41, the central supply port 49, and the passage 31. After being led to the opening 24 and meeting here,
It is extruded through the molding recess 17. At this time,
The cross-sectional shape of the tread rubber 2 is defined by the other end 50 of the opening 24 and the shape of the molded recess 17. Next, if the cross-sectional shape of the tread rubber 2 changes due to a change in tire size,
Perform the conversion. In this case, first, the piston rods 27 and 28 of the cylinders 25 and 26 are operated synchronously to move the shutter 23 to the other side. This movement is caused by one side end 5 of the opening 24.
1, that is, the other end of the first slider 21, stops when it is approximately located on one side 13 of the bypass protrusion 12. As a result, the bypass recess 14 comes to communicate with the opening 24, and the molded recess 17 is connected to the shutter 23, that is, the first slider 21,
Closed by. As a result, the A and B types of rubber in the opening 24 are pushed out through the bypass recess 14, and the A and B types of rubber do not come into contact with the molding recess 17 at all. At this time, the cross-sectional shape of the tread rubber 2 is defined by the shape of the one side end 51 of the opening 24 and the bypass recess 14. here,
Since the bypass recess 14 and the molded recess 17 communicate with each other as described above, the movement stroke of the shutter 23 may be small, and as a result, the cylinder 2
5 and 26 can be made smaller and the manufacturing cost can be reduced. Next, the piston rod 20 of the cylinder 19 is retracted, the mouthpiece 15 is moved in the direction of arrow C, and it is pulled out from the holder 8. Next, insert the molded concave base corresponding to the size you want to change,
Exchange funds. Even during this replacement work, the operation of the heating roll and extruder 1 is not stopped and the treaded rubber 2 is continuously extruded, so the operating conditions at this time, such as the temperature, hardness, extrusion speed, etc. There is almost no difference from the operating conditions during operation, and they are almost the same. At this time, if the amount of change in the width of the tread rubber 2 exceeds a predetermined range, the piston rods 35, 36, 44, 45 of the cylinders 33, 34, 42, 43 will synchronously protrude or retract by the same amount. It will be done. As a result, the pair of center and end inserts 30 and 39 move toward and away from each other centering on the center in the longitudinal direction of the die 4, and the boundary between the A and B type rubbers is well set.
In this way, the inserts 30 and 39 located upstream from the shutter 23 are each divided into two parts in the longitudinal direction, and these parts are made to approach and separate from each other, so that while continuously extruding the tread rubber 2, the A and B type rubbers can be Boundaries can be adjusted. When the exchange of the cap is completed in this way, the cylinder 25,
26 are operated synchronously to move the shutter 23 to one side to the initial position and return it. As a result, the A and B type rubbers are again extruded through the molding recess 17, and the tread rubber 2 having the desired cross-sectional shape can be obtained. Here, when the shutter 23 is moved as described above, since the bypass recess 14 and the molded recess 17 communicate with each other as described above, the communication area between the opening 24 and the bypass recess 14 gradually decreases. On the other hand, the communication area between the opening 24 and the molded recess 17 gradually increases, and the opening 24 is never even partially closed. As a result, the rubber pressure inside the extruder 1 does not fluctuate, and the treaded rubber 2 with a constant cross-sectional shape, that is, with good dimensional accuracy, is produced from the initial stage of restarting extrusion to steady operating conditions. It can be pushed out.

As explained above, according to the present invention, the molded material can be continuously extruded regardless of whether the nozzle is replaced, and as a result, the quality of the molded material can be improved by being able to extrude under steady operating conditions even immediately after the nozzle is replaced. do. Furthermore, the device can be made smaller and cheaper.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a front view thereof, FIG. 3 is a sectional view of the die, and FIG.
The figure is a perspective view of the main parts near the cap, Figure 5 is a cross-sectional view taken in the - arrow direction of Figure 3, and Figure 6 is a cross-sectional view taken in the - arrow direction of Figure 3. The upper half of both Figures 5 and 6 is omitted. has been done. 1... Extruder, 2... Molding material (treaded rubber),
3...Head, 8...Head body (holder),
12... Fixed block (bypass protrusion), 13...
...One side, 14... Bypass recess, 15... Base, 16... Other side, 17... Molding recess, 23...
... Shutter, 25, 26 ... Moving means (cylinder), 24 ... Opening, 50 ... Other side end, 51 ...
...one end.

Claims (1)

[Claims] 1. A head body, a fixing block provided in the head body and having a bypass recess formed on one side thereof, and a fixing block that is replaceably attached to the head body on one side of the fixing block and that is attached to the other side that abuts one side of the fixing block. a base in which a molding recess is formed that faces the bypass recess and has the same cross-sectional shape as the cross-sectional shape of the molded material; possible to engage;
The shutter has a bypass recess or an opening that guides the molding material into the molding recess, and when extruding the molding material through the molding recess, the opening and the molding recess communicate with each other, and the bypass recess is moved by the shutter. When replacing the cap by moving the shutter to one side until it is closed, move the shutter to the other side until the opening and bypass recess are in communication and the molded recess is closed by the shutter. A head for an extruder, comprising a moving means for moving the head laterally.