JP5088818B2 - Resin multiple pipe extrusion molding equipment - Google Patents

Description

  The present invention relates to a resin multi-tube extrusion apparatus in which each resin extruded from a plurality of screw-type extruders is sent to a multi-tube forming die through a positive displacement pump.

  Conventionally, there is an apparatus for extruding a resin multi-pipe shown in Patent Document 1 below. According to this publication, the extrusion molding apparatus forms a multiple tube by passing a plurality of screw-type extruders that are made by hot-melting and extruding a resin, and each resin extruded from each of the extruders. And a positive displacement pump that is interposed between the extruders and the dies and introduces the resins extruded from the extruders, and discharges the resins to feed the dies. I have.

  For example, during the operation of the extrusion molding apparatus in the case of forming a highly accurate multi-pipe having a very small cross-sectional dimension, such as a catheter (conduit) in the medical field, first, the extrusion is performed by driving the extruders. The molten resin is extruded from the machine. Next, these resins pass through the pumps and are fed into the die. And when the resin passes through this die, the multiple tube is continuously formed forward.

  Here, the extruder is a screw type and has the ability to extrude the resin at a high pressure, but due to its structure, an error occurs in the extrusion amount of the resin per unit time with respect to the rotational speed of the extruder. easy. On the other hand, since the pump is a positive displacement type, higher accuracy is ensured in the discharge amount per unit time with respect to the rotational speed of the pump.

For this reason, if the rotational speed of each of the pumps is set to a desired value, each pump can obtain a desired discharge amount with high accuracy corresponding to the rotational speed. Therefore, as the resin passes through each of these pumps, a highly accurate amount of resin is fed from each of these pumps toward the die. As a result, a multiple tube having a high cross-sectional dimension such as the catheter is formed. It is supposed to be obtained.
JP 2002-331562 A

  By the way, the above conventional technique has the following problems.

  That is, firstly, the pumps are dispersedly arranged on the left, right side, and upper surface of the die, and the extruders are arranged around the die in the same manner as the pump. Distributed. For this reason, the extrusion molding apparatus tends to be large as a whole, and a large occupied space is required for installation of the extrusion molding apparatus.

  Second, the die and the pump are connected to each other by a pipe projecting from the die and the pump, and a pair of outward flanges for connecting the protruding ends of the pipes to each other. As the pipes and flanges are present as described above, the volume of the resin flow passage that connects the insides of the die and the pump to each other increases. As a result, the volume of the resin in the resin flow passage increases.

  For this reason, when controlling to change the rotational speed of the pump, the rotational speed may be increased to increase the discharge amount, or the rotational speed may be decreased to decrease the discharge amount. When a pressure change occurs in the resin, the volume change amount of the compression amount or the expansion amount of the resin having a large volume in the resin flow passage as described above tends to be large.

  Therefore, when the discharge amount is changed to a desired value by controlling the rotational speed of the pump described above, the change from the start of the change until the discharge amount of the changed desired value reaches the inside of the die. As described above, since the volume change amount of the resin is large, it is necessary to absorb the change amount, and time is required. In other words, the control of the rotation speed of the pump tends to decrease the responsiveness with respect to the discharge amount of a desired value discharged from the controlled pump reaching the inside of the die. There remains room for improvement in obtaining a multiple tube with high dimensional accuracy that meets the above requirements.

  The present invention has been made paying attention to the above-described circumstances, and an object of the present invention is to make the extrusion molding apparatus compact so that the occupied space can be reduced.

  Another object of the present invention is to obtain a multiple tube with higher dimensional accuracy when the multiple tube is extruded by an extrusion molding apparatus.

The invention of claim 1 is directed to three or more screw-type extruders 6 to 8 which are extruded by melting and melting the resins 3 to 5 and the resins 3 to 5 extruded from the extruders 6 to 8. A die 15 for forming the multi-pipe 2 by passing through, and each of the resins 3 to 5 interposed between the extruders 6 to 8 and the die 15 and extruded from the extruders 6 to 8 are introduced. On the other hand, in a resin multi-pipe extrusion molding apparatus equipped with positive displacement pumps 28 to 30 for discharging the resins 3 to 5 so as to send them to the die 15
The pumps 28 to 30 are concentratedly arranged near the outside of any one of the left, right side surfaces 31 and 32, and the upper and lower surfaces 33 and 34 of the die 15, and the extruders 6 to 8 are arranged. Is provided with a screw extruder main body 9 and an electric motor 10 which is attached to one axial end portion 9b of the shaft center 9a of the screw extruder main body 9 and drives the screw extruder main body 9. The other end 9c of the main body 9 is fastened to each of the pumps 28 to 30, respectively, and the extruders 6 to 8 are arranged radially around the pumps 28 to 30 group,
The resin multi-pipe extrusion molding apparatus is characterized in that the pump cases 37 of the pumps 28 to 30 are integrally molded to form an integral case 40 .

The invention of claim 2 is characterized in that the pump case 37 of each of the pumps 28 to 30 is directly attached to the one surface of the die 15 so that the rotational speed of the pumps 28 to 30 can be controlled. Item 2. An apparatus for extruding a resin multiple tube according to Item 1 .

  In addition, in this section, the reference numerals and drawing numbers appended to the above terms are not intended to limit the technical scope of the present invention to the “Example” section and the contents of the drawings described later.

  The effects of the present invention are as follows.

The invention of claim 1 includes three or more screw-type extruders that melt and extrude a resin, a die that forms a multi-pipe by passing each resin extruded from each extruder forward, and Resin multiple pipe provided with a positive displacement pump that is interposed between each extruder and a die and introduces each resin extruded from each of the extruders and discharges each resin to be fed to the die In the extrusion molding apparatus,
Each of the pumps is concentrated in the vicinity of the outside of any one of the left, right side, top, and bottom surfaces of the die.

  Therefore, compared to the conventional technology in which each pump or extruder is distributed around the die, the above pump groups are arranged in a compact manner, and the extruder groups related to these pumps are also It is arranged compactly as a whole. Therefore, the extrusion molding apparatus becomes compact as a whole, and the occupied space can be reduced.

Each of the extruders includes a screw extruder main body and an electric motor that is attached to one axial end of the axial center of the screw extruder main body and drives the screw extruder main body. The other end of the main body is fastened to each of the pumps, and the extruders are arranged radially around the pump group.

For this reason, although each said extruder is arrange | positioned compactly as mentioned above, the space | interval of the motors of each adjacent extruder can be enlarged, and the wiring, maintenance, and inspection work with respect to these can be performed easily. Convenient.

Also a unitary housing formed integrally with each other pump case of the respective pumps.

  For this reason, each said pump group becomes further compact, an extrusion molding apparatus becomes more compact, and the structure of an extrusion molding apparatus can be simplified more by the reduction of the number of parts in each said pump group.

According to a second aspect of the present invention, the pump case of each pump is directly attached to the one surface of the die so that the rotational speed of each pump can be controlled.

  For this reason, the resin flow passage for communicating the interiors of the die and the pump with each other can be made extremely small, and the volume thereof can be made extremely small.

  Therefore, when controlling to change the rotation speed of the pump, the rotation speed is increased to increase the discharge amount, or the rotation speed is decreased to decrease the discharge amount. When a pressure change occurs in the resin, the volume change amount of the compression amount and the expansion amount of the resin having a small volume in the resin flow passage having a small volume as described above is suppressed to be small.

As a result, when the discharge amount is changed to a desired value by controlling the rotation speed of the pump described above, from the start of this change until the changed discharge amount of the desired value reaches the inside of the die, Since the volume change amount of the resin is small as described above, it takes no time to absorb the change amount. In other words, the control of the rotational speed of the pump improves the responsiveness with respect to the amount of discharge of a desired value discharged from the controlled pump reaching the inside of the die, and thus matches the control. A multiple tube with high dimensional accuracy can be obtained .

  The best mode for carrying out the present invention is as follows, in order to realize the object of making the extrusion molding apparatus compact and reducing the space occupied by the extrusion molding apparatus for resin multiple pipes of the present invention. It is like this.

  That is, the resin multi-tube extrusion molding apparatus includes a plurality of screw-type extruders that melt and extrude the resin, and a die that molds the multi-tube by passing each resin extruded from each of the extruders forward. And a positive displacement pump interposed between each of the extruders and a die for introducing each resin extruded from each of the extruders and discharging the resins so as to be fed into the die. . Each of the pumps is concentrated in the vicinity of the outside of any one of the left, right side, top, and bottom surfaces of the die.

Each of the extruders includes a screw extruder main body and an electric motor that is attached to one axial end of the axial center of the screw extruder main body and drives the screw extruder main body. The other end of each screw extruder body is fastened to each pump, and the extruders are arranged radially with the pump group as a center.

The pump cases of the pumps are integrally formed with each other to form an integrated case.

  In order to explain the present invention in more detail, an embodiment thereof will be described with reference to the accompanying drawings.

  In the figure, reference numeral 1 denotes an extrusion molding apparatus for continuous molding of the resin multi-tube 2. An arrow Fr indicates the front which is the extrusion direction of the multiple pipe 2. The multiple tube 2 is typically a catheter, but is not limited thereto.

  The extrusion molding apparatus 1 includes a plurality (three units) of screw-type first to third extruders 6 to 8 which can extrude thermoplastic resins 3 to 5 which are different in hardness from each other by heat melting with a heater. ing. Each of these extruders 6 to 8 is attached to a screw extruder main body 9 having an axial center 9a extending in the horizontal direction and to one end portion 9b of each screw extruder main body 9 in the axial direction. And a variable speed electric motor 10 to be driven. The screw extruder main bodies 9 of the extruders 6 to 8 are individually supported on the base 12 by the support columns 11.

  The extrusion apparatus 1 includes a die 15 that is supported by the base 12. This die 15 allows the resins 3 to 5 extruded from the other end 9c of the screw extruder main body 9 of each of the extruders 6 to 8 to pass forward to form the multiple tube 2. The die 15 has a rectangular parallelepiped shape, and an inner tube forming passage 16 for forming the inner tube of the multiple tube 2 by allowing the resin 3 extruded from the first extruder 6 to pass therethrough, and a second one. An outer tube forming passage 17 for forming the outer tube of the multiple tube 2 through the resin 4 extruded from the extruder 7 and a resin 5 extruded from the third extruder 8 are passed through the outer tube of the multiple tube 2. An intermediate tube forming passage 18 for forming an intermediate tube between the inner and outer tubes is formed. Each of the tube forming passages 16 to 18 is disposed on a common axis 19 extending in the front-rear direction, and has a conical cylinder shape that is tapered forward.

  First to third resin passages 20 to 22 are formed in the die 15 so that the upstream ends of the pipe forming passages 16 to 18 communicate with the outside of the die 15. These resin passages 20 to 22 are close to each other and extend in parallel to the left and right, and their upstream ends open to the outer surface of the die 15.

  An on-off valve 23 is provided that can open and close a middle portion of each of the resin passages 20 to 22. The on-off valve 23 includes a circular hole 24 formed in the die 15 and a shaft-shaped valve body 25 that is fitted into the circular hole 24 so as to be rotatable about an axis. In FIG. 3, the solid line indicates the open state of the on-off valve 23, and the alternate long and short dash line indicates the closed state of the on-off valve 23.

  The extrusion molding apparatus 1 introduces the resins 3 to 5 that are interposed between the extruders 6 to 8 and the die 15 and are extruded from the extruders 6 to 8, respectively. Are provided with first to third pumps 28 to 30 which are positive displacement gear pumps for discharging so as to feed -5 to the die 15. Each of these pumps 28 to 30 is concentratedly arranged in the vicinity of the outside of the right side 32 which is one of the left and right sides 31 and 32 and the upper and lower sides 33 and 34 of the die 15.

  Each of the pumps 28 to 30 includes a pump case 37, a rotor 38 that is a pair of gears that are housed in the pump case 37 and mesh with each other, and a variable electric motor 39 that drives the rotor 38. Yes. The pump cases 37 are integrally formed with each other to form an integrated case 40. The integrated case 40 is in direct surface contact with the right side surface 32 of the die 15 by a fastener 41, which is a bolt, and uses a piping material. There is no direct conclusion. The other end 9c of each screw extruder body 9 is directly fastened to the die 15. The integral case 40 may be integrally formed with the die 15 and attached integrally to one surface of the die 15.

  The upstream ends of the resin passages 20 to 22 are open to the right side surface 32 of the die 15. In each pump case 37, an introduction passage 44 for communicating the inside of the other end portion 9c of each screw extruder main body 9 with the resin introduction side of each rotor 38, and the resin discharge side of each rotor 38 are respectively described above. A discharge passage 45 communicating with each upstream end of each resin passage 20 to 22 is formed.

  The introduction passages 44 and the discharge passages 45 are disposed on the axis 9 a of the screw extruder body 9. Further, the extruders 6 to 8 are respectively arranged on the right side of the die 15 and are radially arranged around the pumps 28 to 30 in the plan view of the extrusion apparatus 1.

  The extrusion molding apparatus 1 is disposed in front of the die 15, passes through the die 15, cools the multiple pipe 2 that is pushed forward from the die 15, and the cooling device 47 A take-out machine 48 that draws the cooled and hardened multi-pipe 2 forward, a cutting machine 49 that cuts the multi-pipe 2 fed forward from the take-off machine 48 to a desired length, and each of the above extrusions The motor 10 of the machines 6-8, the actuator of each on-off valve 23, the motor 39 of each pump 28-30, the take-up machine 48, and the control apparatus (not shown) which electronically controls the cutting machine 49 are provided.

  When the extrusion molding apparatus 1 is in operation, first, the molten resins 3 to 5 are respectively extruded from the extruders 6 to 8 by driving the extruders 6 to 8. Then, these resins 3 to 5 pass through the pumps 28 to 30 and are fed into the die 15. And when the said resins 3-5 pass through this die | dye 15, the multiple tube 2 is shape | molded continuously toward the front.

  Here, if each rotation speed is set to a desired value by controlling each pump 28-30, each pump 28-30 is a positive displacement type, so that each pump 28-30 corresponds to the rotation speed. A desired discharge amount can be obtained. Therefore, when the resins 3 to 5 pass through the pumps 28 to 30, the amount of the resin 3 to 5 with high accuracy is sent from the pumps 28 to 30 toward the die 15. A multi-tube 2 having a high size can be obtained.

  According to the above configuration, the pumps 28 to 30 are concentratedly arranged in the vicinity of the outer side of any one of the left and right side surfaces 31 and 32 and the upper and lower surfaces 33 and 34 of the die 15.

  For this reason, the pumps 28 to 30 are generally arranged in a compact manner as compared with the conventional technology in which the pumps and the extruders are distributed around the die, and are related to the pumps 28 to 30. Each of the extruders 6 to 8 is arranged compactly as a whole. Therefore, the extrusion molding apparatus 1 becomes compact as a whole, and the occupied space can be reduced.

  Further, as described above, the pump cases 37 of the pumps 28 to 30 are integrally formed with each other to form an integrated case 40.

  For this reason, each said pump 28-30 group becomes still more compact, the extrusion molding apparatus 1 becomes more compact, and the structure of the extrusion molding apparatus 1 becomes more by the reduction in the number of parts in each said pump 28-30 group. Easy to do.

  As described above, the pump cases 37 of the pumps 28 to 30 are directly attached to the one surface of the die 15 so that the rotational speeds of the pumps 28 to 30 can be controlled.

  For this reason, the resin flow passage which makes each inside of the above-mentioned die 15 and pumps 28-30 mutually communicate can be made infinitely small, and the volume can be made very small.

  Therefore, when controlling to change the rotation speed of the pumps 28 to 30, the pump 28 is changed to increase the rotation speed to increase the discharge amount or to decrease the rotation speed to decrease the discharge amount. When the pressure change occurs in the resins 3-5, the resin 3-5 having a small volume in the resin flow passage having a small volume as described above has a small volume change amount of the compression amount and the expansion amount. It is suppressed.

  As a result, when the discharge amount is changed to a desired value by controlling the rotational speed of the pumps 28 to 30, the changed discharge amount of the desired value reaches the inside of the die 15 from the start of the change. By the time, since the volume change amount of the resin is small as described above, it does not take time to absorb the change amount. That is, with respect to the control of the rotational speed of the pumps 28 to 30, the responsiveness with respect to the discharge amount of the desired value discharged from the controlled pumps 28 to 30 reaching the inside of the die 15 is improved. Therefore, it is possible to obtain a multiple tube 2 with high dimensional accuracy that matches the above control.

  Further, as described above, each of the extruders 6 to 8 is attached to the screw extruder main body 9 and one end portion 9b of the axial center 9a of the screw extruder main body 9 in the axial direction. An electric motor 10 to be driven, the other end 9c of each screw extruder main body 9 is fastened to each of the pumps 28-30, and each of the extruders 6-8 is radially centered around the pumps 28-30 group. Is arranged.

  For this reason, although each said extruder 6-8 is arrange | positioned compactly as mentioned above, the space | interval of the electric motors 10 and 10 of each adjacent extruder 6-8 can be enlarged, wiring with respect to these, Maintenance and inspection work is easy and convenient.

The above is due to the illustrated example, the above extruder 6-8 and pump 28-30 may be respectively be four or more. Moreover, you may arrange | position each said extruder 6-8 radially centering | focusing on the pumps 28-30 group by the front (back) view and side view of the extrusion molding apparatus 1. FIG.

1 is an overall plan view of an extrusion molding apparatus. It is a rear view of an extrusion molding apparatus. It is a partial expanded sectional view of what was shown in FIG.

DESCRIPTION OF SYMBOLS 1 Extrusion molding apparatus 2 Multiple pipe 3 Resin 4 Resin 5 Resin 6 Extruder 7 Extruder 8 Extruder 9 Screw extruder main body 9a Axis 9b One end 9c Other end 10 Electric motor 15 Die 16 Inner pipe forming passage 17 Outer pipe forming Passage 18 Intermediate pipe forming passage 20 Resin passage 21 Resin passage 22 Resin passage 28 Pump 29 Pump 30 Pump 31 Side surface 32 Side surface 33 Upper surface 34 Lower surface 37 Pump case 38 Rotor 39 Electric motor 40 Integrated case 41 Fastener

Claims (2)

Three or more screw-type extruders that melt and extrude the resin, a die that forms a multi-pipe by passing each resin extruded from each of the extruders forward, and each of the extruder and the die In the resin multi-tube extrusion apparatus provided with a positive displacement pump that introduces each resin interposed between and extruded from each of the extruders, and discharges each resin to the die,
The pumps are concentratedly arranged near the outside of any one of the left, right side, and upper and lower sides of the die, and the extruders are screw extruder bodies and the screw extruder bodies. And an electric motor for driving the screw extruder main body, the other end of each screw extruder main body is fastened to each pump, and the pump group is centered. As above, each extruder is arranged radially,
An apparatus for extruding a resin multi-pipe, wherein the pump cases of the pumps are integrally molded with each other to form an integral case . 2. The resin multi-pipe extrusion molding apparatus according to claim 1, wherein a pump case of each pump is directly attached to the one surface of the die so that a rotation speed of each pump can be controlled .

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