JPH08132499A - Spiral pipe for cooling core of injection mold, and manufacture thereof - Google Patents

Abstract

PURPOSE: To surely hold the pipe in the hole without slating, render the flow of cooling water uniform, and reduce the adherence of fur so as to reduce the necessity of cleaning by allowing the core-cooling spiral pipe to form ridged projection in a double-spiral form in the periphery of the cylinder. CONSTITUTION: In the core-cooling device, a spiral pipe 3 is formed of a pipe cylinder 3a and double spiral ridged projection 3b made on the peripheral surface, and the diameter of which outer periphery is predetermined so that it can be inserted into the cooling hole 2b. Also, the end of the spiral pipe 3 is secured to a backing plate 2d and the part having the ridged projection 3b of the pipe 3 formed thereon is fitted and arranged within the cooling hole 2b. Then, the cooling flow path 4 of the core 2 is constituted of an inlet flow path 4a, inner flow path of the spiral pipe 3, cooling water spouting part 4c opposite to the gate, spiral flow path formed between the pipe 3 and the cooling hole 2d, and an outlet flow path 4e of a mold plate 2c, thus allowing cooling water to flow in the arrow direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core cooling device for an injection mold.

[0002]

2. Description of the Related Art In a mold core cooling device of an injection molding machine, heat is conventionally exchanged with a resin by using a cooling medium such as water, and various methods and devices are known as a mold core cooling method. Has been. For cooling a small diameter elongated core pin,
The jet method using a pipe has been conventionally used.
This method first cools the hottest gate corresponding point and makes the temperature of the core uniform by parallel flow around the pipe. There is a problem that the flow passages are likely to be non-uniform, and there is a problem that the horizontal mold apparatus is affected by gravity and the cooling water does not flow evenly.

In order to solve these problems, as shown in FIG. 3, a wire 3c is spirally wound around the outer periphery of the pipe to support the pipe concentrically with the cooling hole and form a spiral flow path to make the flow uniform. Conventionally, a method of controlling so as to be set has been proposed.

Further, a cooling cylinder having a thread groove on the periphery and an opening at the center is fitted into the core cooling hole, cooling water is ejected from the central opening to cool the gate corresponding point, and then the screw. A screw-type core cooling method that swirls and flows in a groove has been conventionally known.

[0005]

However, the above wire winding pipe has a problem in that it is difficult to accurately wind the wire at a constant interval and insert it into the cooling hole, and the flow path is not uniform. It was Further, when the core pin has a small diameter, water stains tend to be formed, and the water stains tend to accumulate between the wire and the pipe or the core hole, which often requires cleaning. At that time, there is a problem that it is difficult to remove the wire, and the wire is deformed, so that the wire needs to be rewound when the mold is maintained.

Further, in the screw type cooling method, since it is threaded, it can be used for a core having a relatively large diameter, but it is difficult to apply it to a core having a small diameter. There was a problem that the cooling was not uniform in the circumferential direction. SUMMARY OF THE INVENTION The present invention provides a technical object to solve these problems, improves a pipe used in a jet cooling method to form a spiral pipe, and provides a mold cooling device and a cooling method using the same. And a manufacturing apparatus and a manufacturing method for easily forming a spiral pipe.

[0007]

In order to achieve the above object, the core cooling pipe of the present invention is a core cooling spiral pipe having a chevron projection formed in a double spiral shape on a cylindrical peripheral surface, or a cross section. A spiral pipe for core cooling is used, which is formed by forming a diamond-shaped cylinder into a spiral shape with a certain twist angle.

Regarding the core cooling method, a spiral pipe for core cooling, in which a mountain-shaped ridge is formed in a double spiral shape on the cylindrical peripheral surface, is fitted into the cooling hole of the mold core, and cooling water is ejected from the inside of the pipe. Cooling the gate corresponding point, then adopting the mold core cooling method, characterized in that the cooling fluid is divided into two and swirled and flowed by the double spiral flow path to cool the core. An injection-molding die core cooling device characterized in that a core-cooling spiral pipe, in which a mountain-shaped ridge is formed in a double spiral shape on a circumferential surface of a cylinder, is inserted into a cooling hole of a die core.

Regarding the manufacturing method of the spiral pipe,
It is a split die that has a forming groove with a predetermined twist angle, compresses a predetermined part of the material pipe from above and below and molds it, and feed it while rotating the material pipe with the necessary leads to form the twist angle. The spiral pipe manufacturing method is characterized in that the spiral pipe is molded by pulling out in the direction.

Regarding the manufacturing apparatus, a split die held on a fixed base of a machine base, a feed base provided with a feed shaft, a lead adjustment base supported on an end of the feed base, and the lead adjustment In a spiral pipe manufacturing apparatus including a scroll chuck supported on a table, the split die has a molding surface provided with a molding groove having a predetermined twist angle, and the lead adjustment table has the scroll chuck at an end thereof. A main shaft to which a worm wheel is attached, a worm shaft to which a worm that meshes with the worm wheel is attached, and a transmission shaft that is linked to the worm shaft by a gear mechanism. A spiral pipe manufacturing apparatus is adopted in which a feed shaft and a transmission shaft of the lead adjusting base are linked by a gear train. Further, in the above-mentioned split die, a notch portion is formed on the die facing surface side of a predetermined range of the die forming groove so that the projection to be compression-molded does not become an undercut.

[0011]

Since the mountain-shaped convex strip is formed in a double spiral shape on the cylindrical peripheral surface of the pipe and is fitted into the cooling hole, the pipe is reliably supported in the hole. Further, since the intervals between the ridges are constant, the cooling water flow paths are uniform, and the mountain-shaped ridges allow the cooling water to flow without stagnation.

Since the spiral pipe is inserted into the cooling hole of the mold core and the cooling water is ejected from the inside of the pipe, the hottest gate corresponding point is cooled first like the conventional pipe jet type. Then, the cooling water is divided into two equal parts and swirls along the double spiral flow path, so that the cooling becomes uniform in the circumferential direction.

Since the material pipe is compressed and modeled with a split die having a molding groove having a predetermined twist angle, and the material pipe is rotated by a necessary lead and pulled out in the feed direction, the spiral pipe is formed. Can be easily manufactured.

[0014]

Next, an embodiment of the present invention will be described with reference to the drawings. First, the core cooling device will be described.
In FIG. 1, reference numeral 1 denotes a male mold of an injection molding die, which has a gate portion 1a connected to a nozzle of an injection molding machine. Reference numeral 2 is a male mold, which has a core 2a, a template 2c, and a receiving plate 2d. A cooling hole 2b is provided at the center of the core 2a,
The receiving plate 2d is provided with a cooling water inlet passage 4a, and the template 2c is provided with an outlet passage 4e.

Reference numeral 3 is a spiral pipe, which is composed of a pipe cylindrical portion 3a and a double spiral chevron 3b formed on the peripheral surface thereof, and the diameter of the outer periphery thereof is fitted into the cooling hole 2b. Is formed to have a predetermined diameter.
The end portion of the spiral pipe 3 is attached to the receiving plate 2d, and the portion of the pipe on which the chevron projection is formed is fitted and disposed in the cooling hole 2b. An inlet channel 4a provided in the receiving plate 2d, an internal channel 4b of the spiral pipe 3,
Cooling water jetting part 4c facing the gate, pipe and cooling hole 2
spiral flow path 4d formed between the inner peripheral surface of d,
The core cooling channel is formed from the outlet channel 4e provided in the template 2c, and the cooling water flows in the direction shown by the arrow.

In cooling the molded product, the cooling water is jetted from the internal passage 4b of the pipe as shown by the arrow, first cooling the hottest gate corresponding point of the core, and then halving the cooling water. Swirling and flowing along the spiral flow path 4d. The cooling water can be uniformly cooled in the circumferential direction by swirling and flowing in the double spiral flow path 4d. Further, since the flow path is formed in a convex shape, the cooling water flows without stagnation. Becomes Further, the cross-sectional area of the internal flow path 4b of the pipe is formed to be equal to or slightly larger than the cross-sectional area of the flow path 4d, so that the flow velocity at the outer peripheral portion is increased and the cooling effect is improved.

Next, a modified embodiment of the spiral pipe will be described. FIG. 4 (a) shows a spiral pipe formed by a tubular body 6 having a rhombic cross-section, and the opposing ridgelines on the long and distant sides of the rhomboidal tubular body are formed in a spiral shape having a constant twist angle. Has been done. Further, (b) shows a spiral pipe formed of a tubular body 7 having an elliptical cross section, and the facing surface on the major axis side is formed in a spiral shape. All of which are spiral pipes 3 provided with ridges 3b
Similarly to the above, while being surely held in the cooling hole, the double spiral flow path is formed, and the cooling water flows uniformly, and the same purpose and effect as those of the above-described embodiment can be achieved.

Next, the method for forming the spiral pipe and the forming apparatus will be described. The basic feature of the molding method of the present invention is a two-piece die provided with a molding groove having a predetermined twist angle, and a predetermined position of the material pipe is compressed from above and below to form a mold to form the twist angle. Forming is performed by pulling in the feed direction while rotating the material pipe with the necessary lead.

Hereinafter, the molding method will be described in detail together with the molding apparatus. As shown in FIG. 5, the molding apparatus includes a machine base 10 and a split die 20 supported by a holding base 11 fixed to the machine base via a scroll chuck.
A feed base 30 slidably mounted on the machine base, a lead adjustment base 40 provided at the end of the feed base, and a scroll chuck 50 attached to the lead adjustment base. There is.

As shown in FIG. 9, the machine base 10 is fixed to a machine pillar 16 having a base 17 at the bottom, and a die holding table 11 is fixed to the upper surface thereof. The holding table 1
A two-way scroll chuck 13 is attached to the support frame 12 above 1. In the figure, 14 is a sliding groove, 15
Is a handle insertion port, and an interlocking gear having a spiral groove is mounted inside the chuck 13, and a member engaged with the spiral groove and guided in the sliding groove 14 is a split die 20.
It is fixed to the upper mold 21 and the lower mold 22 (not shown). By inserting the handle into the handle insertion port 15 and rotating the interlocking gear, the upper mold and the lower mold are interlocked and move oppositely.

As shown in FIGS. 6 and 7, the die 20 is
It is composed of an upper mold 21 and a lower mold 22, each of which has a molding surface 23 forming an hourglass shape integrally and a molding groove 24 having a twist angle for forming a spiral chevron shape. ing. The upper mold 21 has screws 21a, 2
The guide pin 25 is attached by 5a and is inserted into the guide hole 22a provided in the lower die 22.

As shown in FIG. 7, the die molding surface has a diameter of the end face 23a of the molding surface 23 which is the same as that of the material pipe in the cross section AA, and the molding groove 24 is horizontal. In the cross section BB, the molding groove 24 is twisted by 45 degrees from the cross section AA, and in the vicinity thereof, the notch portion 27 is formed on the die facing surface side of the molding groove 24 so that the ridge to be molded does not become an undercut. Are formed. In the cross section CC, the molding surface 23c and the molding groove 24 have the same shape and size as the pipe to be molded.
4 is located 90 degrees twisted from the cross section AA,
The total length of the circumference of No. 4 and the circumference of the molding surface is equal to the circumference of the material pipe. In the above embodiment, the twist angle is 90 degrees, but if the twist angle is less than 90 degrees, the spiral can be formed in accordance with the twist angle, and the inclination angle of the molding groove 24 in the cross section AA or CC can be appropriately selected.

Next, the shape of the die for the spiral pipe shown as a modified embodiment in FIG. 4 will be described.
FIG. 8 shows a molding surface 26 for a spiral pipe having a rhombic cross section, and (a), (b), and (c) show the shapes of the portions corresponding to the cross sections AA, BB, and CC of FIG. There is. The cross-sectional shapes of the dies on the cross-sections AA, BB, CC are basically similar shapes, and the cross-sections are successively reduced, and the dice are positioned with a predetermined twist angle. In the AA cross section, a molding surface 2 large enough to enclose the material pipe
6a is formed, and in the vicinity of the cross section BB, a notch portion 27 is formed on the die facing surface side of the mold surface so that the opposing ridge lines of the cylindrical body are not undercut. In the cross section CC, the molding surface 26c has the same shape and size as the cross section of the spiral pipe to be finally molded.
The die for the spiral pipe having an elliptical cross section is not shown and described, but it is the same as the above except that the shape of the mold surface is changed.

In molding, the material pipe is clamped by a scroll chuck and then clamped from above and below with a split die. At that time, the material pipe is pressed from above and below, and the material pipe is not deformed in the cross section AA, but in the vicinity of the cross section BB, the notch portion is formed on the die facing surface side of the die forming groove 24 so that the convex strip does not become an undercut portion. Since 27 is formed, the peripheral surface is compressed as it goes to the cross sections BB and CC, and the portion corresponding to the molding groove 24 is expanded into the groove. In the cross section CC, there is no notch 27, and the raw material pipe is compressed and molded into the final cross sectional shape.

Next, when the raw material pipe is rotated in the Y direction and fed in the X direction so as to generate the same twist as the twist of the shaping groove (detailed later), the cross section A of the raw material pipe is obtained.
The portion at A shifts to the cross sections BB and CC of the die, the peripheral surface is compressed, and the portion corresponding to the mold forming groove bulges to form a spiral pipe. Since the length of the peripheral surface of the raw material pipe is substantially equal to the length of the peripheral surface after molding, the pipe is only compressed and shaped by the upper and lower dies, and is not drawn by drawing. Therefore, it is easy to form, and stainless steel can be easily processed.

Next, the lead adjustment will be described. The lead adjusting mechanism is composed of a feed base, a lead adjusting base, and a gear train that links them. The feed table 30 includes a feed table 31 slidably supported on the machine base, and a feed shaft support piece 32 of the feed table 31 has a feed shaft 33 provided with a feed screw pivotally attached thereto. In FIG. 8, 34 is a guide engaged with the dovetail groove of the machine base, and 35 is a feed handle. The feed shaft 33 is engaged with a female screw (not shown) attached to the machine base 10, and the feed table can be moved by rotating the feed shaft 35 with the feed handle 35. A gear 36a is attached to the tip of the feed shaft 33 via a bush 37, and the rotation is transmitted to a gear 36c attached to a transmission shaft 45 of the lead adjusting base via an intermediate gear 36b.

A lead adjusting table 40 is attached to the end of the feed table 31. The lead adjusting base of the present invention is one to which the technique of the indexing base is applied, and its structure will be described with reference to FIGS. 8 to 10. 41 is a rotary spindle, 42 is a worm wheel attached to the rotary spindle, 43 is a worm, 44
Is a worm shaft, 46a is a bevel gear attached to the worm shaft, 46b is a bevel gear attached to the intermediate shaft 47, 48a,
Reference numeral b is a spur gear, and 45 is a transmission shaft, the end of which is projected to the outside so that the swing arm 38 and the gear can be attached. The bevel gears 46a and 46b and the spur gears 48a and 48b are the same, and the worm shaft 44 and the transmission shaft 45 are rotated at the same rotation speed.

The gears 36a, 36b, 36c constitute a gear train, and a gear having an appropriate number of teeth is selected according to the needs of the leads. The lead of the spiral pipe depends on the size of the mold core and its length, but it is usually 120 m.
Since the pitch of the feed screw of the feed shaft is 6 mm, in this case, the rotation of the feed shaft 33 causes the spindle 4 to rotate.
It is necessary to reduce the rotation of 1 to 1/20. In this case, it is difficult to slow down the rotation between the feed shaft and the main shaft of the lead adjusting table only by the spur gear train, and it is necessary to adjust the rotation by the worm and the worm wheel. If the twist angle is small, scroll chuck 5
When 0 is allowed to rotate freely, the pipe is rotated by the twist angle of the die-forming groove, and a gear wheel may not be used.

Next, the scroll chuck 50 will be described. A three-way scroll chuck 50 for attaching a material pipe is attached to the projecting end of the main shaft 41. In the figure, 51 is a claw, 52 is a sliding groove, and 53 is a handle insertion port. An interlocking gear having a spiral groove inside is mounted on the chuck 50, and a spiral tooth provided on the back surface of the claw 51 is guided in the sliding groove 52 by engaging with the spiral groove (illustration). do not do). When the handle is inserted into the handle insertion port 53 and the interlocking gear is rotated, the pawl 51 can be moved in the same manner. When attaching the pipe material, insert the core into the pipe and firmly clamp it with a chuck.

Next, the operation of the manufacturing apparatus of the present invention will be briefly described. When the feed shaft of the feed base 30 is rotated by the feed handle, the feed base moves, and at the same time, the gear attached to one end of the feed shaft becomes a gear attached to the transmission shaft of the lead adjusting base via the intermediate gear. The rotation is transmitted, and the main shaft is rotated by the worm and the worm wheel of the lead adjusting table, and the material pipe is fed to the die and at the same time, the necessary rotation is given.

In the above embodiment, the feeding is carried out manually, but it is also possible to mount a motor on the feeding table and rotate the feeding shaft by the motor, or fix the feeding table to fix the die holding table. May be moved.

[0032]

Since the present invention is constructed as described above, the following effects are brought about.

As the cooling pipe, a spiral pipe in which a mountain-shaped ridge is formed in a double spiral shape on the circumferential surface of the cylinder is adopted and is fitted into the cooling hole, so that the pipe is securely supported in the hole and inclined. Never. In addition, since the interval between the ridges is constant, the cooling water flow path is uniform, the cross-sectional area of the flow path is uniform, and the cooling water flows uniformly. Since the convex shape is a mountain-shaped convex line, the cooling water flows without stagnation, so that the adhesion of scale is reduced and the need for cleaning can be reduced.

Since the cooling water is jetted from the inside of the pipe, the hottest gate corresponding point can be cooled first like the conventional pipe jet type. Then, the cooling fluid is divided into two equal parts and swirled by the double spiral flow path to cool the core, so that the cooling is uniform in the circumferential direction and the core as a whole can be uniformly cooled.

Since the material pipe is compressed and modeled by a split die having a molding groove having a predetermined twist angle, and the material pipe is rotated by a necessary lead and pulled out in the feed direction, the spiral pipe is used. Can be easily manufactured.

Further, since the lead adjusting base provided with the worm and the worm wheel and the replacement gear train are used, it is possible to easily adjust the necessary lead by replacing the replacement gear.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mold cooling device of the present invention.

FIG. 2 is an explanatory view showing the shape of a spiral pipe in the AA sectional view of FIG.

FIG. 3 is a sectional view of a conventional core cooling device.

FIG. 4 is a sectional view of a modification of the spiral pipe.

FIG. 5 is a perspective view of a pipe forming apparatus.

FIG. 6 is a vertical sectional view of a die.

FIG. 7 is a sectional view taken along lines AA, BB and CC in FIG.

FIG. 8 is an explanatory view of a die cross section of a modified example.

FIG. 9 is a front view of the pipe forming apparatus.

FIG. 10 is a side view of the pipe forming apparatus.

FIG. 11 is an internal perspective view of the lead adjusting base.

[Explanation of symbols]

 1 Male Type 2 Female Type 2a Core 2b Cooling Hole 3 Spiral Pipe 3a Pipe Cylindrical Part 3b Yamagata Projection 4 Cooling Water Flow Path 6 Rhombic Cylindrical Pipe 7 Elliptical Cylindrical Pipe 10 Machine Stand 11 Die Support Fixture 13 Scroll Chuck 20 Split Dice 21 Upper mold 22 Lower mold 23 Molding surface 24 Molding groove 27 Notch 30 Feed bar 33 Feed shaft 36 Gear 40 Lead adjusting base 41 Spindle 42 Worm wheel 43 Worm 44 Worm shaft 45 Transmission shaft 50 Scroll chuck

Claims (7)

[Claims] 1. A spiral pipe for cooling a core, wherein a mountain-shaped ridge is formed in a double spiral shape on a peripheral surface of a cylinder. 2. A spiral pipe for cooling a core, wherein a cylindrical body having a rhombic cross section is formed into a spiral shape with a constant twist angle. 3. A core cooling spiral pipe, in which a mountain-shaped ridge is formed in a double spiral shape on a cylindrical peripheral surface, is fitted into a cooling hole of a mold core, and cooling water is jetted from the inside of the pipe to form a gate corresponding point. A method for cooling an injection mold core, comprising cooling, and then cooling fluid is divided into two and swirled and flowed by a double spiral flow path to cool the core. 4. An injection-molding die core cooling device, characterized in that a spiral pipe having a mountain-shaped convex strip formed in a double spiral shape on a circumferential surface of a cylinder is inserted into a cooling hole of the die core. 5. A halving die provided with a forming groove having a predetermined twist angle, compresses a predetermined portion of the raw material pipe from above and below and molds the raw material pipe, and forms the raw material pipe with necessary leads for forming the twist angle. A method for manufacturing a spiral pipe, characterized in that the spiral pipe is molded by pulling it out in the feed direction while rotating. 6. A split die held on a fixed base of a machine base, a feed base provided with a feed shaft, a lead adjustment base supported at an end of the feed base, and a lead adjustment base supported by the lead adjustment base. In the manufacturing apparatus of the spiral pipe including the scroll chuck, the split die has a molding surface provided with a molding groove having a predetermined twist angle, and the lead adjusting base mounts the scroll chuck at an end portion. A main shaft having a worm wheel attached thereto, a worm shaft having a worm engaged with the worm wheel attached thereto, and a transmission shaft linked to the worm shaft by a gear mechanism, and a feed shaft of the feed table, An apparatus for manufacturing a spiral pipe, wherein the transmission shaft of the lead adjusting base is linked by a gear train. 7. The split die according to claim 5, wherein a notch is formed on the die facing surface side of the die forming groove in a predetermined range so that the projection to be compression-molded does not become an undercut.