JP2005212153A - Cylindrical molded product manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical molded product manufacturing apparatus suitable for manufacturing a small-sized cylindrical molded product by a blow molding method. <P>SOLUTION: A resin material is softened by an extrusion molding machine 10 to be molded into a cylindrical shape and the cylindrical extruded member PT is extruded toward a blow molding machine 20. In the blow molding machine 20, compressed air is injected in the cylindrical extruded member PT from a blow pipe 16 by a pressing machine such as a compressor or the like to press the cylindrical extruded member to the molding surface 23 of a molding unit 21 to mold the cylindrical extruded member PT into a bellows shape. The molded cylindrical extruded member PT is cooled to become a corrugated tube P and slits S are formed to the corrugated tube P by the cutter 50 of a slitter 40. The airtight plug 60 capable of approaching or coming into contact with the inner peripheral surface of the corrugated tube P is held to the cutter 50, and the blow pipe 16 and the cylindrical extrusion member PT are arranged to a mutual contact or approach state to hold the internal space I of the corrugated tube P to an almost airtight state. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an apparatus for manufacturing a cylindrical molded product.

2. Description of the Related Art Conventionally, a blow molding method described in Patent Document 1 below is known as a method for producing a corrugated tube which is a kind of cylindrical molded product. In this blow molding method, as shown in FIG. 10, the soft cylindrical extrusion member 2 extruded from the extrusion molding machine 1 is fed into the blow molding machine 3, and the inside thereof is kept almost airtight and pressurized air is supplied thereto. By feeding in, the extrusion member 2 is pressed against the molding part 4 of the blow molding machine 3 so as to be molded into a predetermined bellows shape.
JP 2000-176997 A

However, this blow molding method requires an airtight plug 5 for keeping the internal space of the extrusion member 2 almost airtight, and a support bar 6 for supporting the airtight plug 5 at a predetermined position in the blow molding machine 3. Therefore, it is difficult to say that it is suitable for manufacturing a small corrugated tube.
The present invention has been completed based on the above circumstances, and an object thereof is to provide an apparatus suitable for manufacturing a small tubular molded article by a blow molding method.

  As means for achieving the above object, the invention of claim 1 is characterized in that the resin material is softened and molded into a cylindrical shape, and an extrusion molding machine for extruding the cylindrical extruded member, and the interior of the cylindrical extruded member. A pressurizing machine that pressurizes the air in the space, an airtight stopper that keeps the internal space of the cylindrical pushing member almost airtight, and a molding part that can mold the cylindrical pushing member pressed by the pressurized air into a predetermined shape. A blow molding machine and a cutter capable of cutting and forming slits in a cylindrical molded product molded by the blow molding machine, wherein the cutter is arranged outside the blow molding machine In addition, the air-tight plug is held by the cutter.

According to a second aspect of the present invention, there is provided the feeder according to the first aspect, wherein the feeder includes a pair of belts which can move the cylindrical molded product by sandwiching the cylindrical molded product and circulatingly running in a caterpillar shape. The cutter is characterized in that it is attached to a slitter provided separately from the feeder.
The invention of claim 3 is characterized in that, in the invention of claim 2, the slitter and the cutter are provided with positioning means capable of positioning the cutter at a predetermined position.

<Invention of Claim 1>
A cylindrical extruded member obtained by molding the softened resin material into a cylindrical shape is extruded. When air is pressurized with a pressurizing machine while keeping the internal space of the cylindrical extrusion member almost airtight with an airtight stopper, the cylindrical extrusion member is pressed against the molding part of the blow molding machine by the pressurized air and molded into a predetermined shape. The Thereafter, a slit is cut and formed by a cutter in the molded cylindrical molded product.
According to the present invention, since the hermetic stopper is held by the cutter disposed outside the blow molding machine, there is no need to arrange the hermetic stopper in the blow molding machine as in the prior art, and a support bar is not required. It is suitable for manufacturing a small cylindrical molded product by the molding method.

<Invention of Claim 2>
For example, in order to place the cutter in the feeder, it is necessary to insert the cutter from the side between a pair of belts sandwiching the cylindrical molded product, but considering the width of the belt, the cutter is much longer. Thus, since sufficient support strength cannot be obtained, a mounting bracket is required separately from the cutter.
On the other hand, in the present invention, a slitter is provided separately from the feeder, and a cutter holding an airtight plug is attached to the slitter, so that the above-described mounting bracket is not necessary.

<Invention of Claim 3>
By positioning the cutter with respect to the slitter by the positioning means, the airtight stopper can also be positioned.

  An embodiment of the present invention will be described with reference to FIGS. In this embodiment, the manufacturing apparatus for manufacturing the corrugated tube P for protecting the wire bundle of the wire harness of a motor vehicle is illustrated. As shown in FIG. 1, the manufacturing apparatus includes an extrusion molding machine 10, a blow molding machine 20, a slitter 40 including a cutter 50, and a feeder 30 in order from the upstream side. In the following description, the downstream side (the left side in FIGS. 1 and 2 and the right side in FIGS. 4 and 5) in the manufacturing apparatus is defined as the front and the opposite upstream side is defined as the rear in the front-back direction.

  As shown in FIGS. 1 and 2, the extruder 10 roughly includes a main body 11, a hopper 12 provided on the upper surface of the rear end of the main body 11, a screw cylinder (not shown) provided in the main body 11, And a nozzle 13 provided at the front end of the main body 11. The hopper 12 can store a pellet-shaped resin material charged into the main body 11. A screw cylinder sends the resin material thrown in into the main body 11 from the hopper 12 ahead. The heater heats the resin material sent by the screw cylinder to a predetermined temperature to bring it into a molten state. The resin material sent in a molten state is molded into a cylindrical shape while passing through the cylindrical path 14 in the nozzle 13 to form a cylindrical extruded member PT, and remains in a softened state from the front end of the cylindrical path 14. Pushed out.

  The cylindrical path 14 is formed between an inner peripheral surface of a die 15 having a circular cross-section hollow space fixed to the main body 11 and an outer peripheral surface of a cylindrical blow pipe 16 provided concentrically in the die 15. Configured. The blow pipe 16 has a front end surface opened forward, and a rear end side connected to a pressurizer such as a compressor (not shown). Therefore, the opening part of the front end in the blow pipe 16 becomes the jet outlet 16a of pressurized air, and the front end part is set to project to the blow molding machine 20 side. The blow tube 16 is held in a positioning state with respect to the die 15 by a predetermined holding structure (not shown). The outer peripheral surface of the blow tube 16 is arranged in contact with or close to the inner peripheral surface of the cylindrical push-out member PT, so that the inner space I of the cylindrical push-out member PT (corrugated tube P) in front of it is arranged. It is almost completely restricted that the air leaks between the two peripheral surfaces, or is difficult to leak.

  The blow molding machine 20 includes the blow pipe 16 described above and a pair of upper and lower molding units 21. The molding unit 21 is configured such that a plurality of molding blocks 22 are connected in a circular shape in a caterpillar shape so as to circulate. The inner circumferential surface of each molding block 22 has a semicircular shape and a circumferential shape. A molding surface 23 having ridges 23a extending in the direction is formed. The upper and lower molding blocks 22 form a substantially circular molding space 24 by facing the molding surfaces 23 in the process of circulation.

  As illustrated in FIG. 1, the feeder 30 includes a pair of belts 31 that sandwich a molded corrugated tube P from above and below. The belt 31 circulates in a caterpillar shape so that the corrugated tube P can be moved from the upstream side to the downstream side.

  Next, the slitter 40, the cutter 50, and the airtight plug 60 will be described in detail. As shown in FIG. 1, the base of the slitter 40 is the same as that of the feeder 30, and is installed immediately behind the feeder 30. As shown in FIG. 3, the slitter 40 is made of metal and has a configuration in which a cutter mounting portion 41 to which the cutter 50 is mounted and an introduction portion 42 for the corrugated tube P are connected back and forth. A substantially circular insertion hole 43 through which the corrugated tube P can be inserted is formed through the entire length in the front-rear direction. As shown in FIG. 4, the introduction portion 42 has a substantially cylindrical shape, and a tapered guide surface 43 a continuous to the insertion hole 43 is formed on the rear surface thereof, so that the corrugated tube P is inserted into the insertion hole. It is possible to guide entry into 43.

  As shown in FIG. 3, the cutter mounting portion 41 has a substantially rectangular parallelepiped shape and a shape in which the upper left portion shown in FIG. 3 is cut out by about ¼, and has a substantially inverted L shape when viewed from the front. ing. A side surface of the cutout portion of the cutter mounting portion 41 serves as a mounting surface 44 for the cutter 50, and on this mounting surface 44, a positioning pin 45 capable of positioning the cutter 50 at a regular mounting position in the height direction and the front-rear direction. A pair of screw holes 46 capable of screwing the cutter holding member 48 for holding the cutter 50 are formed on the left and right sides of the positioning pin 45. An attachment groove 47 in which the cutter 50 can be attached is formed continuously in the attachment surface 44 in the cutter attachment portion 41. The attachment groove 47 opens forward in the cutter attachment portion 41 and also opens in the insertion hole 43 and is connected to each other. The rear edge of the mounting groove 47 is a positioning surface 47a inclined so as to form a downward slope toward the rear. Since the gradient of the positioning surface 47a is set to be substantially the same as the inclination angle of the cutter 50 in the normal mounting posture, the cutter 50 can be positioned in the normal mounting posture (mounting angle).

  As shown in FIGS. 7 and 8, the cutter holding member 48 is made of a long and narrow metal plate, and is attached to the attachment surface 44 so that the cutter 50 can be connected to the attachment surface 44. It can be held as if sandwiched. A pair of screw insertion holes 48a into which the screws 49 can be inserted are formed in the cutter holding member 48. By screwing the screws 49 passed through the screws 49 into the screw holes 46, the cutter holding member 48 is cut into the cutter. The mounting portion 41 can be fixed. The cutter holding member 48 is formed with a notch 48b for releasing the positioning pin 45.

  As shown in FIGS. 4 and 5, the cutter 50 has a sharp notch 51 at the rear edge, and the notch 51 with respect to the cutter mounting portion 41 is in the moving direction of the corrugated tube P. It is attached in a posture inclined at a predetermined angle (for example, about 60 degrees) to form an acute angle. The slits 51 for expanding the corrugated tube P when the electric wire (not shown) is accommodated in the corrugated tube P can be formed by cutting the cut portion 51. The notch 51 is positioned at a regular mounting angle by being abutted against the positioning surface 47a when the cutter 50 is attached to the cutter attachment 41. A positioning hole 52 into which the positioning pin 45 of the cutter mounting portion 41 can be fitted is formed in the upper end portion of the cutter 50. A pair of pin insertion holes 53 into which pins 54 for holding the airtight plug 60 described below can be inserted are formed in the lower end portion of the cutter 50 so as to open sideways.

  The hermetic plug 60 is made of metal, has a generally cylindrical shape that is elongated in the front-rear direction, and a rear end portion that is tapered. A cutter mounting groove 61 penetrating along the vertical direction is formed in a front portion of the airtight plug 60, and a lower end portion of the cutter 50 can be inserted therein. A pair of pin insertion holes 62 into which the pins 54 can be inserted are formed in the airtight plug 60 where the cutter mounting groove 61 is formed. Is formed. The airtight plug 60 can be fixed to the cutter 50 by inserting the pin 54 into the pin insertion holes 53 and 62 aligned with each other from the side. In the fixed state, the hermetic plug 60 is arranged so that the rear side thereof protrudes to the upstream side of the cutter 50, and the axis thereof is substantially horizontal. When the cutter 50 is properly attached to the cutter attachment portion 41, the hermetic plug 60 has an axis substantially parallel (almost horizontal) to the moving direction of the corrugated tube P, as shown in FIG. It is arranged at a position that is concentric with the insertion hole 43 and the corrugated tube P inserted therethrough. Therefore, when the cutter 50 is positioned at the time of attachment to the slitter 40, the airtight plug 60 fixed to the cutter 50 is also positioned at the normal position described above. When exchanging the cutter 50, the pin 54 may be punched and removed with a jig thinner than the pin 54 or the like.

  As shown in FIG. 2, the airtight plug 60 is set so that its outer diameter is substantially the same as or slightly smaller than the inner diameter of the small diameter portion Pa in the corrugated tube P. Accordingly, the outer peripheral surface 60a of the portion of the airtight plug 60 that protrudes upstream from the cutter 50 is disposed in contact with or close to the inner peripheral surface of the small diameter portion Pa of the corrugated tube P. The leakage of the air in the internal space I from between both peripheral surfaces is almost completely restricted or difficult to leak. Accordingly, the internal space I of the corrugated tube P and the cylindrical push-out member PT is maintained as an almost airtight sealed space, coupled with the fact that the blow tube 16 is arranged in contact with or close to the tubular push-out member PT on the upstream side. It has come to droop. Further, since the rear end portion of the hermetic plug 60 is formed in a tapered shape, the entry into the corrugated tube P can be guided.

  The present embodiment has the above-described structure, and the assembly work related to the slitter 40 will be described. First, the operation | work which integrates the cutter 50 and the airtight stopper 60 from the state shown in FIG. 5 is performed. The lower end portion of the cutter 50 is inserted into the cutter mounting groove 61 of the airtight plug 60 from above, and the pins 54 are respectively inserted into the press fitting holes 53 and 62 while being aligned with each other. Thus, as shown in FIG. 4, the airtight plug 60 can be held with respect to the cutter 50.

  Next, an operation of attaching the cutter 50 to the slitter 40 is performed. With the notch 51 of the cutter 50 facing backward, the airtight plug 60 is inserted into the insertion hole 43 and the cutter 50 is inserted into the mounting groove 47. Then, the positioning pin 45 is fitted into the positioning hole 52 of the cutter 50 and the notch 51 is abutted against the positioning surface 47a, thereby positioning the cutter 50 and the airtight plug 60 as shown in FIGS. Is made. While maintaining this state, the cutter holding member 48 is disposed so as to sandwich the cutter 50 with the mounting surface 44, and the screw 49 is screwed into the screw hole 46 aligned with the screw insertion hole 48a. Thereby, as shown in FIGS. 8 and 9, the cutter 50 is fixed in a state of being sandwiched between the cutter holding member 48 and the mounting surface 44. In this state, the cutter 50 and the airtight plug 60 are held in a regular mounting posture.

  Next, the manufacturing process of the corrugated tube P will be described. When a resin material is put into the extrusion molding machine 10 from the hopper 12, the resin material is fed forward by a screw cylinder and heated by a heater to be in a molten state, and as shown in FIG. By passing, it is formed into a cylindrical shape. The tubular extruding member PT is extruded into the molding space 24 of the blow molding machine 20 while remaining in a soft state. In the blow molding machine 20, the cylindrical extrusion member PT is pressed against the molding surface 23 of the molding block 22 by the pressurized air ejected from the jet outlet 16 a of the blow pipe 16 and is brought into close contact therewith. Then, the cylindrical extruding member PT passes through the blow molding machine 20 while being formed into a bellows shape by the ridges 23a.

  By the time it reaches the slitter 40 from the blow molding machine 20, the molded tubular extruded member PT is solidified by being cooled to be a corrugated tube P that is a molded product. The cylindrical extruded member PT and the corrugated tube P are softer at a higher temperature on the upstream side and harder at a lower temperature on the downstream side. The corrugated tube P is smoothly introduced into the insertion hole 43 by the guide surface 43 a of the slitter 40. For the corrugated tube P that has entered the insertion hole 43, the slit S along the axial direction is cut and formed by the notch 51 of the cutter 50 disposed on the moving path in the process of moving to the downstream side. . In the corrugated tube P, the outer peripheral surface 60a of the airtight plug 60 protruding rearward from the cutter 50 is in contact with or close to the inner peripheral surface of the small diameter portion Pa upstream of the rear end position of the slit S. Therefore, the inner space I of the corrugated tube P can be kept almost air-tight regardless of the slit S. The corrugated tube P that has passed through the slitter 40 is wound up by a winder (not shown) after passing through the feeder 30 or a measuring machine (not shown).

  As described above, according to the present embodiment, since the airtight plug 60 is held by the cutter 50 disposed outside the blow molding machine 20, there is no need to arrange the airtight plug in the blow molding machine as in the prior art. Since a support bar is not required, it is suitable for manufacturing a small corrugated tube P by a blow molding method.

  In addition, in this embodiment, a slitter 40 is provided separately from the feeder 30, and a cutter 50 holding an airtight plug 60 is attached to the slitter 40. Therefore, for example, when the cutter is arranged in the feeder 30, it is necessary to insert and arrange the cutter from the side between the pair of belts 31 sandwiching the corrugated tube P. In consideration of this, the cutter becomes much longer and sufficient support strength cannot be obtained, so that a mounting bracket is required separately from the cutter. On the other hand, in this embodiment, the above mounting brackets can be dispensed with. Moreover, the freedom degree of arrangement | positioning of the cutter 50 regarding the circumferential direction in the slitter 40 is also comparatively high.

  Further, the positioning pin 45 of the slitter 40 is fitted into the positioning hole 52 of the cutter 50 and the notch 51 of the cutter 50 is abutted against the positioning surface 47a of the slitter 40, so that the cutter 50 is placed in the normal mounting position.・ It can be positioned in the mounting position.

By the way, as a manufacturing method of the corrugated tube other than the blow molding method as in the present embodiment, there is a vacuum molding method. In this vacuum molding method, a cylindrical extrusion member is fed from an extrusion molding machine to a vacuum molding machine, and air between the cylindrical extrusion member and the molding part of the vacuum molding machine is sucked through a slit formed in the molding part. This is a method of forming a cylindrical extruding member into a predetermined bellows shape by attracting the cylindrical extruding member to the inner peripheral surface of the forming portion. This vacuum forming method eliminates the need for an airtight plug and the like, so that it is suitable for manufacturing a small corrugated tube, but has a demerit that the equipment becomes large, such as a vacuum pump or a forming part with a slit.
Since this embodiment employs the blow molding method, the equipment is simpler than that of the vacuum molding method, and as described above, it is also suitable for manufacturing a small corrugated tube.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) The structure for holding the airtight stopper with respect to the cutter can be arbitrarily changed. Also, the cutter holding structure with respect to the slitter can be arbitrarily changed.

(2) The shape of the cutter, the airtight stopper, and the slitter can be arbitrarily changed.
(3) The feeder may be arranged upstream of the slitter. Further, the slitter may be omitted and the cutter may be attached to the feeder.
(4) The present invention can also be applied to a corrugated tube formed into a shape other than the bellows.
(5) The present invention can also be applied to manufacturing a cylindrical molded product other than a corrugated tube.

Schematic of a corrugated tube manufacturing apparatus according to an embodiment of the present invention. Partially enlarged side sectional view of an extrusion molding machine, blow molding machine and slitter Slitter perspective view Side sectional view showing the state before attaching the cutter to the slitter Side view showing the state before the airtight stopper is attached to the cutter Side sectional view showing a state where the cutter is attached to the slitter Rear view showing the slitter attached to the cutter Side sectional view showing a state in which the cutter holding member is attached Rear view showing a state in which the cutter holding member is attached Cross section of conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Extrusion molding machine 20 ... Blow molding machine 21 ... Molding unit (molding part)
DESCRIPTION OF SYMBOLS 30 ... Feeder 31 ... Belt 40 ... Slitter 45 ... Positioning pin (positioning means)
47a ... Positioning surface (positioning means)
50 ... Cutter 51 ... Cutting part (positioning means)
52 ... Positioning hole (positioning means)
60 ... Airtight plug I ... Internal space P ... Corrugated tube (cylindrical molded product)
PT ... Cylindrical extrusion member S ... Slit

Claims (3)

While extruding the cylindrical material by softening the resin material, and extruding the cylindrical extrusion member,
A pressurizing machine for pressurizing the air in the internal space of the tubular extruding member;
An airtight stopper that keeps the internal space of the cylindrical pushing member almost airtight;
A blow molding machine provided with a molding part capable of molding the cylindrical pushing member pressed by pressurized air into a predetermined shape;
It is equipped with a cutter that can cut and form a slit for a cylindrical molded product molded by the blow molding machine,
The cutter is disposed outside the blow molding machine, and the airtight stopper is held by the cutter. It comprises a feeder having a pair of belts that can move the cylindrical molded product by sandwiching the cylindrical molded product and circulating and running in a caterpillar shape,
The said cutter is attached to the slitter provided separately from the said feeder, The manufacturing apparatus of the cylindrical molded product of Claim 1 characterized by the above-mentioned. The apparatus for manufacturing a cylindrical molded article according to claim 2, wherein the slitter and the cutter are provided with positioning means capable of positioning the cutter at a predetermined position.

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