JPH0375116A - Injection molding device with positioning flange - Google Patents

Abstract

PURPOSE: To reduce the loss of the heat transmitted to a low temp. cavity plate through a positioning flange by providing a large number of openings to the outwardly extending positioning flange so as to pierce the flange laterally according to a definite shape. CONSTITUTION: A manifold 18 made of copper has a circumferential positioning flange 20 which extends outwardly to be seated on the circumferential shoulder part 22 formed by the inner surface 23 of the deep bore of a cavity plate 26. By this constitution, the manifold 18 fixed at a predetermined position and a nozzle 14 are accurately positioned and, at this position, the nozzle is received in the center of a deep bore 24 through the heat insulating air space 28 extending to the gap between the high temp. nozzle 14 and the peripheral low temp. cavity plate 24. The positioning flange 20 has a ring of laterally drilled bores 30 and, by these bores, the loss of the heat reaching the low temp. cavity plate 26 from the high temp. manifold 18 and the high temp. nozzle 14 through the positioning flange 20 is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates generally to injection molding, and more particularly, a circumferential locating flange extends outwardly across an air gap from a hot nozzle or manifold to connect the nozzle to a cold cavity plate. This invention relates to an injection molding device that positions in deep holes.

BACKGROUND OF THE INVENTION Injection molding apparatus having a hot nozzle extending from a hot manifold to a cold cavity plate and transporting high pressure melt through a melt passage to a gate leading to the cavity are known in the art. To minimize heat loss from the hot nozzle to the cold cavity plate, an insulating air gap is provided between them. However, this air gap must be bridged by a device that accurately positions the nozzle within the deep hole of the cavity plate and supports the nozzle pressure. Typically, seals and positioning devices are provided near the forward end of the nozzle and positioning devices are formed toward the rear end of the nozzle to maintain accurate alignment of the nozzle within the deep bore. For example, Applicant's U.S. Pat. Disclosed. Patent No. 4゜768.
No. 283 and No. 4.7 patented on the 20th of the same month of the same year.
No. 71,534 and No. 4,588.367, issued to Shutt on May 13, 1986, disclose a nozzle having an insulating flange extending across an insulating air gap and contacting a surrounding cavity plate. has been done.

A nozzle having an insulating ring or hoop with circumferentially extending grooves or protrusions is disclosed in my U.S. Pat. Canadian Patent Application No. 56 filed in Japan
No. 9,756. A device for providing additional insulation for hot nozzles is shown in U.S. Pat. No. 4,795,338, issued January 3, 1989.

No. 4.705.473, issued Oct. 10, 1987 to Schmidt, shows a valve pin bushing having a locating flange mounted between each nozzle and manifold. Thus, nozzles with positioning flanges are known and are satisfactory for many applications.

[Problem to be solved by the invention]

However, in injection material molding equipment with a strict temperature window, the heat losses from the hot nozzle and manifold through the locating flange to the cold cavity have become increasingly severe due to the unsatisfactory operation of this type of equipment.

It is therefore an object of the present invention to at least partially overcome the disadvantages of the prior art by reducing the heat loss through the locating flange to the cold cavity plate.

[Means and effects for solving the problem] Therefore, the present invention provides a high temperature launch injection molding apparatus with a valve gate, which comprises:
The device has a hot nozzle with a rear face fixed to a hot manifold, the hot nozzle being received in a deep hole having an inner surface in a cold cavity plate, and an insulating air gap between the nozzle and the surrounding cavity plate. the manifold and the nozzle having a melt passageway extending therethrough for transporting high pressure melt to a gate leading to the cavity, the nozzle extending in contact with a surrounding cavity plate from the melt passageway to an insulating air gap. It has a seal and a positioning member to prevent leakage of the melt. Further, one of the hot nozzle and manifold has an outwardly extending circumferential positioning flange that extends across the insulating air gap and contacts a deep hole inner surface of a surrounding cavity plate at a predetermined location; In particular, the present invention provides a valve gated hot launch injection molding apparatus as described above, wherein the locating flange seats on a rearwardly facing circumferential shoulder formed by the inner surface of the deep hole to position the nozzle within the deep hole. The locating flange extends into a valve gated hot launch injection molding apparatus having a plurality of openings laterally extending therethrough according to a constant shape.

Further objects and advantages of the invention will become apparent from the following description based on the drawings.

〔Example〕

Referring first to FIG. 1, the valve member 10 of the illustrated central entry valve gated injection molding apparatus is received in the central bore 12 of a nozzle 14, which is secured to a manifold 18 by bolts 16.

The steel manifold 18 has a circumferential locating flange 20 extending outwardly to a circumferential shoulder 22 formed by the inner surface 23 of the deep hole 24 in the cavity plate 26.
is seated. This precisely positions the manifold 18 and nozzle 14 to be fixed in place, in which the nozzle is inserted into the deep hole 24 through an insulating air gap 28 extending between the hot nozzle 14 and the surrounding cold cavity plate 24. accepted at the center of As shown in FIG. 3, in this embodiment, the locating flange 20 has a ring of laterally drilled holes 30 that pass through the locating flange 20 from the hot manifold 18 and nozzles 14 to the cold cavity plate 26. Reducing heat loss. In this embodiment of the invention, a single cavity plate 2
Although 6 is shown, various other plate arrangements may be provided, such as a support plate provided between the cavity plate 26 and the back plate 32. Nozzle 14 and manifold 18 are also laterally positioned by a forward nose portion 34 of nozzle 14, with nozzle 14 being received through cavity plate 26 and into a corresponding cylindrical opening 36 by rear end 38 of manifold 18; Rear end 38 of manifold 18
are received into corresponding openings in the locating collar 40;
and retained. The locating collar 40 is secured in place by bolts 42 that extend through the back plate 32 and into the cavity plate 26.

A central hole 12 through the nozzle 14 extends through a rear portion 44 and a nose portion 34 of the nozzle, with a larger diameter forward portion 46 forming a gate 48 with a forward opening 50.
has. Valve member 10 has a forward portion 52 , a central portion 54 extending through rearward portion 44 of central bore 12 , and a rearward portion 56 extending into central opening 58 of manifold 18 . As shown, the forward portion 52 of the valve member 10 is smaller in diameter than the forward portion 46 surrounding the central nozzle aperture 12 such that the nozzle aperture 12 forms a melt flow gap therebetween; has an enlarged forward end 62 that seats in the opening 50 of the gate 48 in the retracted closed position. The enlarged end 62 of the valve member 10 has a flat front surface 64 that has the same operating temperature in the closed position as the same side 66 of the cavity 68. The central portion 54 of the valve member 10 has a number of spaced protrusions 7.
0, and the protrusion 70 has a central nozzle hole 1 passing through the nozzle 14.
2 to prevent leakage of high pressure melt around the reciprocating valve member 10.

In this embodiment, nozzle 14 is heated by a heating plate 72 fixed on the opposite side as shown in FIG. Manifold 18 is heated by electrical heating elements 74 that are threaded or cast together.

Cavity plate 26 is cooled by pumping cooling water through cooling conduit 76 . In large volume configurations with the front face 64 of the valve member extending into this cavity 68, it is desirable to further cool the enlarged end of the valve member 10. Thus, a torsion bulkhead 78 is mounted within the hollow valve member 10 and circulation of cooling water is provided through inlet and outlet tubes extending laterally from the rear portion 56 of the valve member 10 through the lateral openings 84, 86 of the manifold 18. 80.82.

The cooling fluid then enters the valve member 10 and enters the inlet pipe 80.
, along one side of the torsional septum 78 to the enlarged end 62 , across which it flows rearwardly along the other side of the torsional septum 78 and out through the outlet tube 82 . In other embodiments, the cooling fluid that passes from the artificial tube 8o through the hollow valve member 10 to the outlet tube 82 may be air rather than water.

As shown in FIG. 1, a melt passageway 88 extends from a central port 90 at the rear end 38 of the manifold 18 to the gate 48 for transporting high pressure melt. The passage 88 is a bifurcated pipe 92
which extend around an opening 58 in the manifold;
It opens into a gap 60 around the front part 52 of the valve member 1o. Although the forward portion 52 of the valve member 1° is shown to be smaller in diameter than the central portion 54 in this embodiment, this is not necessary. What is important is that the central nozzle hole 12
The forward portion 46 of the valve member 10 is sufficiently larger than the forward portion 52 of the valve member 10 to form a gap with a cross-sectional area sufficient to transport melt received through the branch tube 92 of the melt passageway 88. That's true. The injection pressure of the melt is applied to the valve member 1.
0 to the forward open position, the melt flows through the gate 48
through and outwardly around the enlarged head 62 of the valve member 10.

Valve member 10 extending within central opening 58 of manifold 18
The rear portion 56 has a smaller diameter neck 94 that joins a rearwardly extending larger diameter portion 96 at a shoulder 98 . Cervical 9
4 extends between this outwardly extending rearward shoulder 98 and an outwardly extending forward shoulder 100 where it joins the central portion 54 of the valve member 10 . A split ring 102 is longitudinally engaged with the valve member 10 and is mounted around the neck 94 of the valve member 10 and extends through the central opening 5 of the manifold 18.
8 so that it can reciprocate. Split ring 102
has a notch 104 for receiving an inner end 106 of the pivoting lever member. Lever member 108 is biased by a compression spring 110 seated in a cylindrical opening 112 in manifold 18 .

In use, the device is assembled as shown by inserting the valve member 10 through the central bore 12 of the nozzle 14 and then attaching the two segments of the split ring 102 around the neck 94. As shown, there is sufficient clearance to effectuate assembly when the valve member 10 is in the retracted, closed position. Spring 110 and lever member 108 are installed in place and nozzle 14 is bolted to manifold 18. Power is supplied to nozzle 14 and manifold 18
is supplied to terminals 114 of heating plate 72 and heating element 74 in order to heat it to a constant working temperature. High pressure melt from a melting machine (not shown) is introduced into melt passageway 88 through the central passageway according to a scheduled cycle. When injection pressure is applied, the force of the melt on the enlarged end 62 of the valve member 10 overcomes the force of the spring 110 and drives the valve member 10 to the forward open position. The melt flows through melt passageway 88 and gate 48 until cavity 68 is filled. When the cavity 68 is filled, the forward facing surface 6 of the valve member
4 and the back pressure of the melt in the cavity 68 against the spring 11
0 forces cooperate to drive valve member 10 to the retracted, closed position, and enlarged front end 62 closes corresponding opening 50 of gate 48.
sit down. The force of spring 110 is applied by lever member 108 to split ring 102, which transmits the force to valve member 10 by contacting outwardly extending rearward shoulder 98. The reception of the split ring 102 in the central opening 58 of the manifold 18 contacts the valve member 102 to hold it in place as the split ring reciprocates between open and closed positions. The injection pressure is then released and, after a short cooling period, the mold is opened to eject the molded product. After evacuation, the mold is closed, injection pressure is reapplied, and gate 48 is reopened. This cycle is continuously repeated at a frequency depending on the size of the cavity and the type of material being molded. As shown, the movement of the valve member 10 is relatively short, but the large cavity forms the enlarged end 62 of the valve member and the opening 50 of the gate 48.
Fills quickly due to its large diameter. The shape of the enlarged end 62 and opening 50 causes the high pressure melt to expand outwardly as it enters the cavity 68. This results in a radial molecular alignment of the melt, which is advantageous for increasing the strength of products with certain shapes. In order for the equipment to work well when forming a material, heat lost from the hot manifold 18 and nozzles 14 to the surrounding cavity plate 26 should be minimized, and accurate positioning of the nozzles 14 in the cavity plate deep holes 24 should be ensured. Must be strictly maintained.

This means that (nose portion 34 and positioning collar 40
Accurate positioning is achieved by the positioning flange 20, while the through ring-shaped hole 30 limits heat losses by limiting the effective cross-sectional area.

4 and 5 show an injection molding apparatus with a valve gate according to another embodiment of the invention. In this case, the common long manifolds 12 each seat in deep holes 122 in the cavity plate 124.
A number of hot nozzles 120 are provided to receive the melt from 6. A high temperature circular manifold 128 connects each nozzle 1
20 and the long manifold 126 by bolts 130. Each nozzle 120 has a circumferential positioning flange 132 extending outwardly into the deep bore 120.
It seats on a circumferential shoulder 134 formed by an inner surface 136. This allows the nozzle 120 to be heated by an integral electric heating element 140 and the cooling conduit 1
The deep hole 122 is precisely positioned with an insulating air gap 138 between it and the surrounding cavity plate 124 which is cooled by feeding cooling water through the cavity plate 42 . In this embodiment of the invention, the locating flange 132, which is placed on the nozzle 120 rather than the circular manifold 128, has two rings of holes 144 drilled therethrough to reduce heat loss. Other shaped lateral openings through the locating flange 132 also reduce heat loss from the hot nozzle 120 to the cold cavity plate 124.

Each nozzle 120 has a central bore that receives a hollow valve member 148 as before. However, in this embodiment, the valve member 148 has a tip 15 that seats in a tapered gate 152 formed by a nose portion 154 of the nozzle.
has 0. Therefore, in this embodiment, the valve member 1
48 is driven forward to the closed position rather than as described with respect to the first embodiment. Valve member 148 is driven forward to a closed position by a pivoting actuation mechanism (not shown) that includes a lever member mounted between an air piston and a split ring that engages the valve member. Cooling water or air passes through the hollow valve member 148 and into the torsion bulkhead 15.
6 from the inlet pipe to the outlet pipe as described above.

The long manifold 126 has a back plate 162 and a cavity plate 1.
24 by a central locating ring 164 and a titanium pressure pad 166.

The elongated manifold 126 is heated by an integral electrical heating element 168, which is described in my U.S. Pat. No. 4,688.622, issued Aug. 25, 1987.
As stated in the issue, it will be cast into it. Positioning ring 164 forms another insulating air gap 170 between hot manifold 126 and cavity plate 124 .

Melt passages 172 extend from inlet 174 and branch at long manifolds 126 into respective circular manifolds 128 where two
It branches into two branch pipes 176 that extend around the valve member actuation mechanism and join the central bore 146 of each nozzle 120 . As mentioned above, the central hole 146 is sufficiently larger in diameter than the valve member to transport the melt forward to the gate 152 leading to the cavity 178.

In use, the apparatus of the present invention is assembled as shown and high pressure melt is injected by a melting machine (not shown) into melt passageway 172 through central port 174 according to a constant cycle. The pressure of the melt retracts the valve member to the open position and high pressure melt flows through melt passageway 172 and gate 152 until cavity 178 is filled.

Once the cavity is filled, air pressure is applied to drive valve member 148 forward to the closed position where valve member 14
The tip 150 of the 8 is seated on the gate 152. The injection pressure is then released and, after a short cooling period, the mold is opened for evacuation. After evacuation, the mold is closed, injection pressure is reapplied, gate 148 is reopened, and the cycle is repeated continuously.

Although the description of an injection molding apparatus with a thermally positioned flange has been made in terms of a preferred embodiment, it should not be considered in a limiting sense. Various modifications and variations will occur to those skilled in the art.

〔Effect of the invention〕

The present invention provides a valve-gated hot runner injection molding apparatus in which an outwardly extending locating flange is provided with a number of laterally extending openings according to a certain shape, thereby reducing heat loss through the locating flange and reaching the cold cavity plate. can be reduced.

FIG. 3 is a perspective view of a portion of the nozzle shown.

DESCRIPTION OF SYMBOLS 10... Valve, 14... Nozzle, 20... Positioning flange, 22... Circumferential shoulder, 24... Deep hole,
26... Cavity plate, 30... Hole, 40... Collar, 48... Gate, 72... Heating plate, 76...
- Cooling conduit, 120... Nozzle, 132... Positioning flange, 144... Hole, 148... Valve member.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a portion of an injection molding apparatus according to an embodiment of the invention; FIG. 2 is a first sectional view showing a valve member in open and closed positions;
3 is a perspective view of the manifold and nozzle shown in FIGS. 1 and 2; FIG. 4 is a sectional view of an injection molding apparatus according to another embodiment of the present invention;

Claims (1)

Claims: 1. An injection molding apparatus with a positioning flange, the apparatus having a hot nozzle with a rear surface fixed to a hot manifold, the hot nozzle having a deep hole having an inner surface in a cold cavity plate. an insulated air gap extends between the nozzle and a surrounding cavity plate, the manifold and the nozzle having a melt passageway extending therethrough for transporting high pressure melt to a gate communicating with the cavity; has a seal and locating member extending in contact with the surrounding cavity plate to prevent leakage of melt from the melt passage into the insulating air gap; one of the hot nozzle and the manifold has an outwardly extending circumferential locating member; a flange, the flange extending across the insulating air gap and contacting the deep hole inner surface of the surrounding cavity plate at a predetermined location, the locating flange extending in a rearwardly facing circle formed by the deep hole inner surface; In an injection molding device with a locating flange that seats on a circumferential shoulder and positions a nozzle in a deep hole, the outwardly extending locating flange has a plurality of openings extending laterally therethrough according to a predetermined shape. Injection molding equipment. 2. The injection molding apparatus of claim 1, wherein the hot nozzle has an outwardly extending locating flange. 3. The injection molding apparatus of claim 1, wherein the aperture extending laterally through the circumferential locating flange forms a first ring of spaced holes extending around the locating flange. 4. The injection molding apparatus of claim 2, wherein the aperture extending laterally through the circumferential locating flange forms a second ring of spaced holes extending around the locating flange. 5. The injection molding apparatus of claim 1, wherein at least a portion of the manifold extends into a deep hole in a cold cavity plate, an insulating air gap is formed between the manifold and the surrounding cavity plate, and the manifold has an outwardly extending locating flange. 6. The injection molding apparatus of claim 5, wherein the aperture extending laterally through the circumferential locating flange forms a first ring of spaced holes extending around the locating flange. 7. The injection molding apparatus of claim 5, wherein the aperture extending laterally through the circumferential locating flange forms a second ring of spaced holes extending around the locating flange.