JP2014218028A - Corrugate tube manufacturing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrugate tube manufacturing apparatus and method which can reduce the length of a thickness changing part.SOLUTION: At the time of shifting between thin molding operation of molding a corrugate tube C into thin thickness and thick molding operation of molding the corrugate tube C into thick thickness, the rotation number of a roller 33 is controlled to make the moving speed of a mold 31 arranged on transportation means 32 lower than that during the thin molding operation and during the thick molding operation, and a gear pump 24 is controlled to perform low speed operation of making the discharge amount of a resin material smaller than that during the thin molding operation and during the thick molding operation, whereby the molding speed of the corrugate tube C is decreased at the time of changing the thickness thereof to reduce the length of a thickness changing part.

Description

  The present invention relates to a corrugated tube manufacturing apparatus and a corrugated tube manufacturing method for manufacturing a corrugated tube using a mold.

  Conventionally, as a corrugated tube manufacturing device, an extruder for discharging a resin material and a molding machine for pressing with a plurality of molds provided on a pair of annular conveying means, and the moving speed of the mold can be changed. (See, for example, Patent Document 1). The corrugated tube manufacturing apparatus described in Patent Document 1 can manufacture a corrugated tube having an arbitrary thickness by increasing the moving speed of the mold to decrease the thickness and decreasing the thickness to increase the thickness. It is like that.

JP 2010-260241 A

  However, in the corrugated tube manufacturing apparatus described in Patent Document 1, when changing the wall thickness of the corrugated tube, the corrugated tube is formed while the moving speed of the mold is changed. There is a disadvantage that a portion (thickness changing portion) that gradually changes along the direction (longitudinal direction of the tube) is formed. In addition, if the speed is changed suddenly, a large load is applied to the device, and when the device is enlarged, the inertial force increases and a greater force is required to change the speed. It was difficult to reduce the size.

  The objective of this invention is providing the corrugated tube manufacturing apparatus and corrugated tube manufacturing method which can make the length dimension of a thickness change part small.

  The corrugated tube manufacturing apparatus of the present invention includes an extruder for discharging a molten resin material, a molding machine for pressing and molding the resin material while feeding the resin material in an axial direction, and a control for controlling the extruder and the molding machine. A corrugated tube manufacturing apparatus comprising: a pair of annular conveying means provided to face each other; and the pair of conveying means to rotate the opposing surfaces to each other in the axial direction. And a plurality of dies arranged side by side on the conveying means, and the resin is disposed on the outlet side of the extruder by changing the passage amount of the resin material. A restricting portion for adjusting the discharge amount of the material is provided, and the control means controls the moving means and the restricting portion to change the moving speed of the mold and the discharge amount of the resin material. Thickness Switching between a thin molding operation for thin molding and a thick molding operation for molding the thick wall, and during the thin molding operation, the moving speed of the mold is increased to a thin molding speed, and the thick wall molding operation is performed. During the molding operation, the mold moving speed is reduced to a thick molding speed, and during the transition between the thin molding operation and the thick molding operation, the mold moving speed is made lower than the thick molding speed, A low-speed operation is performed in which the discharge amount of the resin material is less than that during the thin-wall molding operation and during the thick-wall molding operation.

  According to the present invention as described above, the wall thickness is changed by performing low-speed operation that lowers the moving speed of the mold at the time of transition between the thin-wall molding operation and the thick-wall molding operation and reduces the discharge amount of the resin material The forming speed of the corrugated tube at the time becomes low. Here, the length dimension of the thickness change part is a value obtained by integrating the molding speed of the corrugated tube with the time required to change the thickness, and since the molding speed of the corrugated tube is lowered, the moving speed of the mold is shortened. The length dimension of the thickness changing portion can be reduced without changing with time. Further, since the mold is controlled so as to move at a low speed only in the low-speed operation, it is possible to suppress a decrease in manufacturing efficiency.

  At this time, in the corrugated tube manufacturing apparatus of the present invention, the control means is configured such that the ratio between the moving speed of the mold and the discharge amount of the resin material is the ratio at the time of transition between the thin wall molding operation and the thick wall molding operation. Switching between a first transition operation equal to that during thin-wall molding operation, a second transition operation including the low-speed operation while the ratio changes, and a third transition operation where the ratio is equal to that during the thick-wall molding operation. preferable. According to such a configuration, the wall thickness does not change from the thin molding operation during the first transition operation, and the wall thickness does not change from the thick molding operation during the third transition operation. By changing the wall thickness only in the second transition operation, the time for changing the wall thickness can be shortened and the forming speed of the corrugated tube when changing the wall thickness can be minimized. Further, the length dimension of the thickness changing portion can be further reduced.

  Furthermore, in the corrugated tube manufacturing apparatus of the present invention, it is preferable that at least one of the plurality of molds is provided with a marker that indicates a start position of thickness change, and includes a marker detection unit that detects the marker. . According to such a configuration, the start position of the thickness change can be accurately determined by detecting the marker provided on the mold. Here, the marker may be provided in one mold, may be provided in a plurality of two or more molds, may be provided in all molds, and each type is identified. If the marker is provided so that it can be done, the thickness can be accurately changed at an arbitrary position.

  On the other hand, the corrugated tube manufacturing method of the present invention is a corrugated tube manufacturing method in which a molten resin material is discharged and the resin material is pressed while being fed in the axial direction. By rotating the annular conveying means so that the opposing surfaces move in the axial direction, pressing is performed by a plurality of molds arranged in parallel on the conveying means, and the discharge amount of the resin material is adjusted, A thin-wall molding process for forming the corrugated tube thinly by moving the mold at a high speed, a thick-wall molding process for forming the thick wall by moving the mold at a low speed, and the thin-wall molding process Between the thick molding process, the moving speed of the mold is made lower than that in the thick molding process, and the discharge amount of the resin material is made lower than in the thin molding process and the thick molding process. Characterized in that it comprises a low speed step.

  According to the present invention as described above, similarly to the corrugated tube manufacturing apparatus described above, it is possible to manufacture a corrugated tube in which the length dimension of the thickness changing portion is reduced without reducing the manufacturing efficiency.

  According to the corrugated tube manufacturing apparatus and the corrugated tube manufacturing method of the present invention as described above, the low speed operation (low speed process) is performed between the thin wall molding operation (thin wall molding process) and the thick wall molding operation (thick wall molding process). By being performed, the length dimension of the thickness change part of a corrugated tube can be made small.

1 is an overall view showing a corrugated tube manufacturing apparatus according to an embodiment of the present invention. It is a timing chart which shows the procedure of the control at the time of corrugated tube manufacture by the said corrugated tube manufacturing apparatus. It is sectional drawing which shows the said corrugated tube. It is sectional drawing which shows the corrugated tube which concerns on the modification of this invention. It is a timing chart which shows the procedure of control at the time of corrugated tube manufacture by the corrugated tube manufacturing apparatus of a prior art.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a corrugated tube manufacturing apparatus 1 according to this embodiment includes an extruder 2 that is supplied with a thermoplastic resin material and discharges the resin material, and a plurality of molds 31 that use the discharged resin material as a plurality of molds. And a forming machine 3 for forming the corrugated tube C by pressing and an identification sensor 4 as marker detecting means for identifying the plurality of molds 31. In the present embodiment, the left-right direction in FIG. 1 is the X direction, the front-rear direction with respect to the page is the Y direction, the up-down direction is the Z direction, and the front-rear, up-down, left-right is based on FIG.

  The extruder 2 includes a supply unit 21 into which a resin material is charged, a screw 22 that has a spiral ridge, extends in the X direction, rotates by a motor (not shown), and melts while feeding the resin material to the right in the X direction; A cylinder 23 that accommodates the screw 22 and forms a passage for resin material; a gear pump 24 that is provided on the right side in the X direction as an outlet of the cylinder 23 and adjusts the passage amount of the resin material; and a gear pump 24 And a nozzle 25 provided on the right side in the X direction, which is the outlet side of the resin, and discharges the resin material to the right side in the X direction.

  The gear pump 24 includes a pair of gears 241 arranged in parallel in the Z direction and having a rotation shaft in the Y direction. The number of rotations of the gear 241 is controlled by a computer (not shown) as control means, and the amount of resin material passing therethrough changes. To do. In the present embodiment, it is assumed that the screw 22 rotates at a constant speed during operation of the extruder 2, that is, the discharge amount of the resin material is determined by the passage amount in the gear pump 24. Here, the computer calculates the arrival time Δt from when the resin material is discharged until it is pressed based on the distance from the outlet of the gear pump 24 to the position where the resin material is pressed and the number of rotations of the screw 22. .

  The molding machine 3 has a pair of conveying means 32 arranged in parallel in the Z direction and having an opposing surface 32a, and a plurality of carrier bases arranged in an annular shape, and a rotating shaft in the Y direction arranged inside the conveying means 32. And a plurality of dies 31 provided on each carrier base. The pulley 33 is disposed inside the conveying means 32 and has a pulley 34 having a rotation axis in the Y direction. The roller 33 is rotated by a motor (not shown) to move the conveying means 32, and the pulley 34 is rotated according to the movement of the conveying means 32, so that the motor, the roller 33, and the pulley 34 function as moving means. The plurality of molds 31 are provided with different markers (not shown) (not shown), for example.

  The roller 33 on the upper side in the Z direction rotates counterclockwise, and the roller 33 on the lower side in the Z direction rotates clockwise, so that the facing surface 32a moves to the right in the X direction. Here, the plurality of molds 31 starts pressing the resin material at the left end in the X direction of the facing surface 32a, and sends the molded corrugated tube C to the right side in the X direction. The number of rotations of the roller 33 is controlled by a computer, and the mold 31 is provided with a variable moving speed. Here, since the rotation of the roller 33 is directly transmitted to the conveying means 32, it is assumed that there is no time difference between the rotation of the roller 33 (rotation of the motor) and the movement of the conveying means 32.

  The identification sensor 4 detects the marker of the mold 31 immediately before pressing and transmits a detection signal to the computer. The computer that has received the detection signal in this way calculates the time from the detection of each die 31 to the start of pressing based on the number of rotations of the roller 33 (that is, the moving speed of the die 31). To do.

  Hereinafter, the operation procedure of the corrugated tube manufacturing apparatus 1 and the manufacturing method of the corrugated tube C will be described with reference to FIG. The forming speed of the corrugated tube C is equal to the moving speed V of the mold 31, and the thickness D of the corrugated tube C is determined by the ratio R between the moving speed V and the discharge amount Q of the resin material. The dimension L in the X direction of the portion where the thickness changes (thickness changing portion) is given by the time integral VT of the molding speed at the time T required for the change in the ratio R. In the present embodiment, a first process for changing the thickness from thin D1 to a thick D2 and a second process for changing from D2 to D1 will be described as an example. In the present embodiment, as shown in FIG. 3, the first step and the second step are performed near the boundary between the corrugated portion C1 where unevenness is formed and the straight portion C2 where unevenness is not formed.

  In the first step, first, the thin wall thickness is set to D1, where the moving speed of the mold 31 is the thin molding speed Vh1, the discharge amount of the resin material is the steady discharge amount Qh (the rotation speed of the gear pump 24 is the steady rotation speed Fh). Molding operation is performed (thin-wall molding process). Next, in order to reduce the molding speed of the corrugated tube C while maintaining the thickness at D1 (first transition operation), when the identification sensor 4 detects the mold 31 for starting the thickness change, the rotational speed of the gear pump 24 Is set to the minimum rotational speed Fl (the discharge amount of the resin material is the minimum discharge amount Ql), and after the arrival time Δt has elapsed, the set value of the moving speed of the mold 31 is reduced to the thin minimum speed Vl1. Let it begin. Here, the ratio Rh1 between Vh1 and Qh is equal to the ratio Rl1 between Vl1 and Ql, and the rotation speed F of the gear pump 24 (the discharge amount Q of the resin material) and the gold so as to keep the wall thickness D1 during the change. The moving speed V of the mold 31 is linearly changed at substantially the same time (T1). Further, the total time of the arrival time Δt and T1 is controlled to be equal to the time from the detection of the mold 31 to the start of pressing.

  Next, in order to change the ratio R to change from the thickness D1 to D2 (second transition operation), the reduction is started with the set value of the moving speed as the thickness minimum speed V12 (low speed process). At this time, the moving speed of the mold 31 is between the thin-wall minimum speed Vl1 and the thick-wall minimum speed Vl2, and the discharge amount of the resin material is the minimum discharge amount Ql, and the low-speed operation is performed. Here, the dimension L in the X direction of the thickness changing portion is proportional to the area of the trapezoid VT with the time T2 required for the change as the height and Vl1 and Vl2 as the upper and lower bases.

  Next, in order to increase the molding speed of the corrugated tube C while maintaining the thickness at D2 (third transition operation), the set value of the moving speed of the mold 31 is set to the thick molding speed Vh2 to start the increase. At this time, the set value of the rotation speed of the gear pump 24 is set to the steady rotation speed Fh (the discharge amount of the resin material is steady) before the arrival time Δt before the moving speed of the mold 31 becomes Vl2 and the second transition operation ends. The discharge amount Qh) starts to rise. Here, the ratio Rl2 between Vl2 and Ql is equal to the ratio Rh2 between Vh2 and Qh, and the rotational speed F of the gear pump 24 and the moving speed V of the mold 31 (resin so as to keep the wall thickness D2 during the change. The material discharge amount Q) is linearly changed at substantially the same time (T3). After T3 has elapsed, a thick molding operation is performed (thick molding process).

  In the second step, the thickness D is changed in the reverse procedure of the first step. When the mold 31 is detected during the thick molding operation, the reduction is started with the set value of the rotation speed of the gear pump 24 as Fl (the discharge amount of the resin material is the minimum discharge amount Ql). The set value of the moving speed of the mold 31 is set to the thick minimum speed Vl2 to start the decrease (third transition operation). Next, the set value of the moving speed of the mold 31 is set to the thin minimum speed Vl1 to start the increase, and the thickness is changed from D2 to D1 (second transition operation and low speed operation). Next, an increase is started with the set value of the rotation speed of the gear pump 24 as the steady rotation speed Fh (the discharge amount of the resin material is the steady discharge quantity Qh) earlier than the end of the second transition operation by the arrival time Δt. After the transition operation is completed, the moving speed of the mold 31 is set as the thin molding speed Vh1 to start the increase (first transition operation). After T1 has elapsed, the process returns to the thin-wall molding operation again.

  According to this embodiment, there are the following effects. That is, when the thickness D is changed during low-speed operation, the area of the trapezoid VT is reduced as compared with the conventional corrugated tube manufacturing method as shown in FIG. The dimension L in the X direction can be reduced. In this way, the area of the trapezoid VT can be reduced without reducing the time (T2) required for the change in the moving speed V of the mold 31, and a load on the molding machine 3 due to a sudden speed change is prevented. be able to.

  Further, since the low speed operation is performed only when the thickness D is changed, the corrugated tube C can be formed by moving the mold 31 at the thin molding speed Vh1 or the thick molding speed Vh2 when the thickness D is not changed. It is possible to prevent the manufacturing efficiency from being lowered.

  Further, by starting the change of the rotational speed F of the gear pump 24 before the change of the moving speed V of the mold 31 by the arrival time Δt, the change of the discharge amount Q of the resin material is changed to the moving speed V of the mold 31. Can start at the same time as the change.

  Further, the identification sensor 4 identifies the mold 31 provided with different markers, so that the thickness can be changed at an arbitrary position.

  In addition, this invention is not limited to the said embodiment, Including other structures etc. which can achieve the objective of this invention, the deformation | transformation etc. which are shown below are also contained in this invention. For example, in the embodiment, the first transition operation and the third transition operation in which the molding speed of the corrugated tube C is increased and decreased while maintaining the ratio R between the moving speed of the mold 31 and the discharge amount Q of the resin material before and after the low speed operation. However, the ratio R (thickness D) does not have to be maintained before and after the low-speed operation as long as the thickness D is changed during the low-speed operation. If the control for maintaining the ratio R, that is, the control for synchronizing the rotational speed F of the gear pump 24 (the discharge amount Q of the resin material) and the moving speed V of the mold 31 is omitted, the control can be simplified.

  In the above embodiment, the plurality of molds 31 are provided with different markers and detected by the identification sensor 4. However, at least one mold 31 is provided with a marker and the period of the conveying means 32 is determined. Accordingly, the thickness D may be changed. If the number of markers is reduced, the configuration of the identification sensor 4 can be simplified. Further, the marker and the identification sensor 4 may be omitted. For example, if the computer determines the change position of the thickness D by calculating the moving distance of the conveying means 32 based on the rotation speed and diameter of the roller 33, The thickness D can be changed at an arbitrary position, and the marker and the identification sensor 4 can be omitted to simplify the configuration.

  In the embodiment, the change in the rotation speed F of the gear pump 24 is started earlier than the change in the moving speed V of the mold 31 by the arrival time Δt of the resin material. The change with the moving speed V of the mold 31 may be started at the same time, and if the control does not take the arrival time Δt into consideration, the control can be simplified.

  In the above embodiment, the thickness D is changed by changing only the moving speed V of the mold 31 during low-speed operation. However, the moving speed V of the mold 31 and the discharge amount Q of the resin material are set as follows. The thickness D may be changed by changing the ratio R between the two. If the control for changing both is performed, the time required for changing the ratio R can be shortened, and the dimension L in the X direction of the thickness changing portion can be further reduced.

  In the above-described embodiment, the rotation speed of the screw 22 is constant. However, the rotation speed is changed simultaneously with the gear pump 24, and the discharge amount Q of the resin material is determined by the screw 22 and the gear pump 24. It is good also as control. With such control, the time required for changing the discharge amount Q of the resin material can be shortened.

  Moreover, in the said embodiment, although the resin material of the thermoplastic resin and the metal mold | die 31 were illustrated, the appropriate material for shape | molding the corrugated tube C should just be used, and if the appropriate mold | type suitable for material is used. Good.

  Moreover, in the said embodiment, although the 1st process and 2nd process which change the thickness D between two types of thickness D1 and D2 were illustrated, a change is performed between three or more types of thickness. May be. Further, not only the control timing exemplified as the first step or the second step, but also if the ratio R is changed during low-speed operation, each parameter may start to change at an arbitrary timing.

  In the embodiment, the thickness D is changed between the corrugated portion C1 and the straight portion C2. However, as shown in FIG. 4, the thickness change is performed in the corrugated portion C1. Alternatively, it may be performed in the straight portion C2.

  In addition, the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations. Therefore, the description limiting the shape, material, etc. disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which remove | excluded the limitation of one part or all of such is included in this invention.

DESCRIPTION OF SYMBOLS 1 Corrugated tube manufacturing apparatus 2 Extruder 3 Molding machine 4 Identification sensor (marker detection means)
24 Gear pump (throttle means)
31 Mold
32 Conveying means 32a Opposing surface 33 Roller (moving means)
34 Pulley (moving means)

Claims (4)

Corrugated tube manufacturing comprising: an extruder that discharges a molten resin material; a molding machine that presses and molds the resin material while feeding the resin material in an axial direction; and a control unit that controls the extruder and the molding machine. A device,
The molding machine includes a pair of annular conveying means provided opposite to each other, a moving means for rotating the pair of conveying means to move the opposing surfaces in the axial direction, and a parallel arrangement on the conveying means. A plurality of molds configured, and
On the outlet side of the extruder, there is provided a throttle portion that adjusts the discharge amount of the resin material by changing the passage amount of the resin material,
The control means controls the moving means and the throttle part to change the moving speed of the mold and the discharge amount of the resin material, thereby reducing the thickness of the corrugated tube and reducing the thickness of the corrugated tube. Switching between a thick-wall molding operation for forming a thick thickness, and during the thin-wall molding operation, the mold moving speed is increased to a thin-wall molding speed, and during the thick-wall molding operation, the mold moving speed is decreased. Then, when moving between the thin wall molding operation and the thick wall molding operation, the moving speed of the mold is made lower than the thick wall molding speed, and the discharge amount of the resin material is set to the thin wall molding speed. A corrugated tube manufacturing apparatus that performs low-speed operation that is less than during operation and during the thick-wall molding operation.   The control means, at the time of transition between the thin-wall molding operation and the thick-wall molding operation, a first transition operation in which the ratio between the moving speed of the mold and the discharge amount of the resin material is equal to the thin-wall molding operation, The corrugated tube manufacturing according to claim 1, wherein the second transition operation including the low speed operation and the third transition operation in which the ratio is equal to that in the thick molding operation are switched while the ratio is changed. apparatus. At least one of the plurality of molds is provided with a marker indicating a start position of thickness change,
The corrugated tube manufacturing apparatus according to claim 1, further comprising marker detection means for detecting the marker. A corrugated tube manufacturing method in which molten resin material is discharged, and the resin material is pressed while being fed in the axial direction.
By rotating a pair of annular conveying means provided opposite to each other so that their opposing surfaces move in the axial direction, pressing is performed by a plurality of molds arranged in parallel on the conveying means,
A thin-wall molding process in which the mold is moved at a high speed to form a thin corrugated tube;
A thick-wall molding step in which the mold is moved at a low speed to thicken the wall thickness;
Between the thin-wall molding step and the thick-wall molding step, the movement speed of the mold is made lower than that in the thick-wall molding step, and the discharge amount of the resin material is lower than those in the thin-wall molding step and the thick-wall molding step. A corrugated tube manufacturing method comprising: a low-speed process.

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