JPH02125709A - Molding device, molding method and transfer jig for plastic - Google Patents

Abstract

PURPOSE:To manufacture a plastic molded product of high accuracy and high quality without distortion by putting molten resin into a cavity of a first molding die, inserting later a projected section of a second molding die into said cavity and applying given pressure. CONSTITUTION:As a heating cylinder 23 is heated to a proper temperature by a heater 15, a material pellet 18 transferred is plasticized. The plasticized resin preformed in a preforming cavity 6 with low pressure and without offsetting through a nozzle section 16. Simultaneously, a finished molded product 9 molded in the foregoing cycle is ejected into a molded product receiving section 7 by operating an ejection section 13. When both actions are completed, the molding resin is slid with a transfer jig 5 by a slider cylinder 11, and the preforming cavity 6 is transferred to the center of a bottom force 4, and the molded product receiving section 7 is transferred to a molded product delivery section on a guide 10 outside a rest 2. Then, a blank 8 in the preforming cavity 6 is supplied forcibly into the cavity of the bottom force 4 by operating the ejection section 13 after lowering a top force 3 to a certain extent.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to plastic molding, and in particular to a molding apparatus and a molding method suitable for precision molding and supply assembly of small plastic parts, and a transport jig suitable for the same. Regarding ingredients.

[Conventional technology]

Conventionally, a method is known in which a molten resin is poured into a molding die for the cylinder 1, and a second molding die is combined with the first molding die under pressure to easily obtain a resin molded product.

What is described in Japanese Patent Application Laid-Open No. 60-162614 is also
Similar to this technology.

This publication describes a molding machine that moves a nozzle in a complicated manner to match the cavity of a first mold, fills the cavity with molten resin, and then performs pressure molding.

[Problem to be solved by the invention]

In the conventional technology, it is necessary to move the nozzle in a complicated manner, resulting in an expensive device, and since the flow path is long from the plastic part to the nozzle, it is necessary to avoid excessive cooling and hardening of the resin. consideration will be required.

For example, in the injection molding method, an injection pressure higher than necessary must be applied to the resin in order to compensate for the injection pressure loss that inevitably occurs due to flowing through a narrow and long flow path. As a result, the internal strain of the resin increases, reducing the precision of the molded product, and at the same time, the specifications and size of the molding machine become unnecessarily large. Since the flow direction is unidirectional, the flow direction is also strong.

The purpose of the present invention is to incorporate a molding method that does not apply unnecessary stress during the molding process in order to obtain high-precision molded products with low distortion, and to provide a molding machine suitable for molding and assembly. There is a particular thing.

Particularly, in addition to the above-mentioned problems, it is an object of the present invention to provide an unprecedented small-sized molding device that is highly versatile and optimal for directly linking the molding process and assembly of plastic parts.

[Means to solve the problem]

The purpose of the above is to shorten and uniform the flow distance during pressure molding of the resin, by introducing the plasticized material into the preforming cavity in the open state at low pressure without shifting, and creating a blank that resembles the finished product. preform and quickly and reliably feed it into the mold cavity. Immediately after processing and forming with a mold, or during preforming, flow distance, direction,
This can be achieved by setting the amount etc. arbitrarily.

In addition, regarding miniaturization, the pressure forming part and the plasticizing part, which have a long structure, should be arranged close to each other in the vertical direction, and these units should be integrated by a transfer unit for the blank and the molded product. This is achieved by configuring forming and discharging in a straight line.

To explain in more detail, the present invention involves putting a molten resin into a cavity of a first molding die, later inserting a protrusion of a second molding die into this cavity, applying a predetermined pressure, In a method for obtaining a resin molded product having a predetermined shape determined by the above-mentioned two molds, a plasticizing section (I) constituted by linearly arranging a hopper, a heater, a nozzle, etc., and a plasticizing section (I) parallel to or parallel to this plasticizing section (I). a pressure molding section (II) that is placed substantially parallel to each other and in which a molding cylinder and a second molding die are linearly arranged; a preforming section that can come into contact with the nozzle of the plasticizing section (I); A first molding die to be combined with the second molding die of the pressure molding section (II) is provided on the base, and the preformed product preformed in the preforming section is transferred to the first molding die. Transfer unit (III) conveying to the mold cavity
The molten resin is moved perpendicularly or almost perpendicularly to the plasticizing part (I) and the pressure molding part (II), and the molten resin is put into the cavity of the first molding die, and then , the protrusion of the second molding die is inserted into this cavity and a predetermined pressure is applied to obtain a resin molded product with a predetermined shape determined by the two molds, which comprises a hopper, a heater, a nozzle, etc. plasticized part (I
), a pressure molding section (II) consisting of a molding cylinder and a second molding die, a preforming section capable of contacting the nozzle of the plasticizing section (I), and a pressure molding section ( A first molding die to be combined with the second molding die of (ii) is provided on the base, and the preformed product preformed in the preforming section is conveyed to the cavity of the first molding die. A transfer unit (III) is provided, and this transfer unit (III) performs the preforming process and the ejection of the molded finished product by interacting with the other preforming section (I) and the pressure molding section (II).
Alternatively, the process of transporting the preform above the first mold and the process of transporting the ejected finished molded product to the outside, or the process of dropping the preform into the cavity of the first mold and the process of transporting the ejected finished molded product to the outside. It is a plastic molding method in which the extraction step is performed at the same time, and the molten resin is preformed in a preforming section CI),
The preformed product is transferred to the first part of the pressure forming section (II).
into the cavity of the second molding die, and later insert the protrusion of the second molding die into this cavity and apply a predetermined pressure to obtain a resin molded product with a predetermined shape determined by the two molds. A transfer jig for a transfer unit (III) that transfers a preform formed in a preforming section (I) to a pressure forming section (II), which is used for The method is characterized in that a preforming cavity and a molded product receiving part are provided to match the spacing between the part (I) and the pressure molding part (II), and the transfer jig is moved with a stroke of the said spacing. It is used as a transport jig.

[Effect]

The internal strain in the resin of the preform, which is preformed without deviation under low pressure, is small and stable.

In addition, since it is preformed to approximate the finished product, the flow distance during pressure molding is short and uniform.

Therefore, the processing distortion of the molded product is small and uniform, and high-precision molding is possible.

Regarding miniaturization, the pressure forming section and the plasticizing section are placed close to each other in the vertical direction, and the preform and finished molded product are transferred linearly using a transfer jig for each unit, making the device extremely compact. Miniaturized.

Then, preforming of the plasticization/blank, ejection of the pressure molded finished product, transportation of the preform, removal of the molded product, insertion of the preform and removal of the molded product, and pressure molding are performed organically. Therefore, it is an optimal molding device with automatic molding and one supply and one assembly.

Furthermore, since the transfer jig is provided with a preforming cavity and a molded product receiving portion, it becomes a transfer jig suitable for this type of molding apparatus that involves preforming.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

First, in FIG. 1, a guide 10 is placed on the top surface of the base 1.
．． Lower mold 4, which is the first molding die. Slider cylinder 1
1. An iron frame 2 is assembled. The slider cylinder 11 is provided with a preformed cavity 6 via a mounting plate 22.
A transfer jig 5 having a molded product receiving portion 7 is slidably assembled.

2 is a transfer unit including this transfer jig 5.

The pedestal 2 has an upper mold 3° molding cylinder 12. which is a second molding mold. Pressure molding section consisting of eject section 13■
and a nozzle portion 16 that is in contact with the upper surface of the transfer jig 5. Heating cylinder 23. Heater 15. A plasticizing section I including a hopper 19 is assembled.

At the center of the hopper 19 is a stirring rod 17. which is rotated by a motor 2o. A screw 14 is installed. The transfer section 5 shown in FIG. 2 includes a preformed cavity 6,
Molded product receiving part7. The escape holes 21 of the upper die 3 are arranged at appropriate pitches.

Incidentally, the distance between the preforming cavity 6 and the molded product receiving portion 7 is made to match the distance between the plasticized portion (3) and the pressure molded portion (H).

Next, the operation will be explained.

The material 18 in the hopper 19 is stirred by a stirring rod 17 that is rotated by a motor 20, and is sent into a heating cylinder 23 by a screw 14. Since the heating cylinder 23 is heated to an appropriate temperature by the heater 15, the fed material pellets 18 are plasticized.

As shown in FIG. 3, the plasticized resin is
6 into the preforming cavity 6 under low pressure without any deviation.

This preforming also serves as an accurate calculation.

At the same time, the ejection section 13 is operated to eject the molded finished product 9 that has been molded in the previous cycle into the molded product receiving section 7. When both operations are completed, the transfer jig 5 is slid by the slider cylinder 11 as shown in FIG.
The preform cavity 6 is transferred to the center of the lower mold 4, and the molded product receiver 7 is transferred to the molded product transfer portion on the guide 10 outside the pedestal 2.

Here, the blank 8 in the preforming cavity 6 is forcibly fed into the cavity of the lower mold 4 by operating the ejector 13 after lowering the upper mold 3 a little. At the same time, the molded finished product 9 in the molded product transfer section is taken out and carried out to the next process.

Next, as shown in FIG. 5, the transfer jig 5 is slid and retreated by the slider cylinder 11 until the escape hole 21 of the mold is aligned with the mold position. Then, due to the mold clamping operation of the forming cylinder 12, the blank 8 that was supplied into the lower mold 4 in the previous process is
Press and form.

After the molding and cooling time has elapsed, the molding cylinder 12 rises and the upper die 3 rises. At this time, the molded product rises along with the upper mold 3.6 After the mold is opened, the transfer jig 5 retreats to its original position (the right end in FIG. 1) and moves on to the next cycle. When the transfer jig 5 is at a position other than the origin, the top surface of the transfer jig 5 and the tip of the nozzle section 16 are always in contact, preventing the plasticized resin from leaking from the tip of the nozzle section 16. It is designed to prevent Upper mold 3, lower mold 4. A cooling or heating flow path may be provided above the preforming cavity 6 and the heating cylinder 23 of the transfer jig 5.

Next, another embodiment will be described with reference to FIG. A blank supply unit 29 is installed in the center of the preforming unit 27 and the pressure forming unit 28, and the pressure forming unit 2
A molded product take-out unit 30 is arranged in a straight line on the opposite side of 8. A preforming cavity 6 is attached to the hand 33 of the blank supply unit 29, and receives resin flowing from the nozzle 16 to preform a blank. Next, the blank is pressed into the pressure forming unit 2 by sliding and rotating motion.
8 to the lower mold 4. The blank is inserted into the mold by the ejecting operation of the upper mold 3, returns to its original position, and moves on to the next process. When the molding of the pressure molding unit 28 is completed, the hand 33 of the molded product take-out unit 30 comes to receive the molded product between the molds.

A molded product receiving portion is attached to the tip of the hand 33.

When the molded product 9 ejected from the upper mold 3 is received, it is taken out from the mold through a sliding and rotational motion, and the molded product 9 is moved to the next process.

In this way, each unit operates organically in this embodiment as well.

Next, referring to FIG. 7, still another embodiment will be described. A preforming unit 27 and a pressure molding unit 28 are incorporated into the pedestal 2. The preforming unit 27 includes
There is a heater 15 for melting the resin, and the heat is transferred to the surroundings. By providing the slit portion 26 in the pedestal 2, thermal deformation of the device and deterioration in accuracy due to heat conduction were prevented.

First, another embodiment of the transfer jig will be described with reference to FIG. A plurality of preform cavities 6 and molded product receivers 7 are attached to a rotatably incorporated endless chain 31 or a belt, and the preformed blanks are supplied and molded products are taken out by transporting them.

Next, referring to FIG. 9, two other embodiments of the transfer jig will be described. Inside the heating cylinder 23, there is a screw 14 for feeding the resin while kneading it, and the outside cylinder is connected to the heater 1.
5 is wrapped around it. The tip of the nozzle portion 16 is in slidable contact with the upper surface of the transfer jig 5. The resin in the heating wJ23 is heated and melted by the heater 15, and the screw 1
4, the transfer jig 5 passes through the nozzle part 16.
into the preforming cavity 6 and is preformed. The transfer jig 5 then slides into the preform cavity 6 to the lower mold, and the blank 8 is inserted into the mold.

The preform cavity 6 is provided with a taper 32 to facilitate detachment of the preform blank from the piece.

Further, the tip of the nozzle portion 16 is in contact with the upper surface of the transfer jig 5 to prevent resin from leaking.

Next, the last embodiment will be explained with reference to FIG. Preforming unit 27. Pressure molding unit 28. The molded product removal unit 30 was arranged linearly. In this example,
The process from material supply, plasticization, preforming, molding, and finished product discharge is carried out in a straight line, making it advantageous for incorporation into narrow automated equipment.

According to the various embodiments described above, the following effects are achieved by the configuration of one embodiment.

(I) Since the pressure molding part and the plasticizing part are arranged close to each other in the vertical direction, it is possible to construct an apparatus with a small planar projected area. Therefore, it can be installed and used in a narrow space, especially on a desk.

(2) By combining it with a transfer unit, a robot, etc., it is possible to configure an automatic molding device that operates organically.

(3) By providing a slit portion in the frame, unnecessary heat transfer can be prevented.

(4) By using an endless transfer unit, the speed can be increased.

(5) Trolling from the nozzle tip is prevented by using a tapered preformed cavity.

This is advantageous for detaching the blank from the preformed piece.

(6) Since each unit is arranged linearly, it is advantageous as an automated element equipment.

There are effects such as

〔Effect of the invention〕

As described above, the present invention firstly puts the molten resin into the cavity of the first molding die, and later inserts the protrusion of the second molding die into this cavity and applies a predetermined pressure. grant,
In a method for obtaining a resin molded product having a predetermined shape determined by the above-mentioned two molds, a plasticizing section (I) constituted by linearly arranging a hopper, a heater, a nozzle, etc., and a plasticizing section (I) parallel to or parallel to this plasticizing section (I). and a pressure molding section (II) which is placed almost parallel to each other and has a molding cylinder and a second molding die arranged linearly.

A preforming part that can come into contact with the nozzle of the plasticizing part (I) and a first molding mold that is combined with the second molding mold of the pressure molding part (II) are provided on the base, a transfer unit (III) that transports the preformed product preformed in the preforming section to the cavity of the first molding die;
Since it is configured to move perpendicularly or almost perpendicularly to the plasticizing section (I) and the pressure forming section (U), it is compact, and the installation area is particularly small, so it can be placed on a desk as a small article forming machine. becomes possible to use. Furthermore, since the product is preformed into a shape close to the finished product and then pressure molded quickly, it is possible to obtain a high-precision, high-quality plastic molded product without distortion.

Second, the molten resin is put into the cavity of the first molding die, and later, the protrusion of the second molding die is inserted into this cavity, and a predetermined pressure is applied, so that the two molds are When obtaining a resin molded product with a predetermined shape determined by a mold, a plasticizing section (I
)and.

a pressure molding section (II) comprising a molding cylinder and a second molding die; a preforming section capable of contacting the nozzle of the plasticizing section (I); A transfer unit that provides a first molding die combined with a second molding die on a base and transports a preformed product preformed in a preforming section to a cavity of the first molding die. (III)
The transfer unit (III) performs the preforming process and ejects the formed finished product, or transfers the preformed product to the second stage through mutual action with the other preforming section (I) and the pressure forming section (II). A method in which the process of transporting the preformed product above the first mold and the process of transporting the ejected finished molded product to the outside, or the process of dropping the preformed product into the cavity of the first mold and the process of taking out the finished molded product are performed simultaneously. Therefore, two steps can be performed at the same time, speeding up the work.

Thirdly, the molten resin is preformed in the preforming section (I), the preformed product is put into the cavity of the first molding die of the pressure forming section (II), and later, The protrusion of the second molding die is inserted into this cavity and a predetermined pressure is applied to obtain a resin molded product with a predetermined shape determined by the two molds. A transfer jig for a transfer unit (III) that transfers a molded preform to a pressure forming section (II). The above-mentioned molding apparatus and molding method can be simplified by using a transfer jig that is provided with a preforming cavity and a molded product receiving part in accordance with the spacing, and moves this transfer jig with a stroke of the above-mentioned spacing. This has the effect that it can be provided.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a small molding machine according to the first embodiment of the present invention, Fig. 2 is a plan view of a transfer jig, and Figs. 3 to 5 show operating states of the transfer jig. 6 is a partially sectional side view of another embodiment, FIG. 7 is a perspective view of another embodiment, and FIG. 8 is a side view showing another embodiment of the transfer jig. FIG. 9 is a partially sectional side view of another embodiment, and FIG. 10 is a side view of another embodiment. DESCRIPTION OF SYMBOLS 1... Base, 2... Frame, 3... Second molding mold (upper mold), 4... First molding mold (lower mold), 5
... Transfer jig, 6. Preformed cavity, 7.
- Molded product receiving part, 8... Blank, 9... Molded finished product, 1o... Guide, 11... Slider cylinder, 1
2... Molding cylinder, 13... Eject part, 14
... Screw, 15 ... Heater, 16 ... Nozzle part, 17 ... Stirring bar, 18 ... Material (pellet), 1
9...Hopper, 20...Motor, 21...Escape hole,
22... Mounting plate, 23... Heating tube, 24... Member,
25... Supply port, 26... Slit part, 27...
Preforming unit, 28... Pressure forming unit, 29
...Blank supply unit, 30 Molded product take-out unit, 31... Chain, 32... Taper part, 33...
hand. Direction number 2. Zuyaku 6 Nikkei] Mouth

Claims (1)

[Claims] 1. Putting the molten resin into the cavity of the first molding die,
Later, the protrusion of the second molding die is inserted into this cavity and a predetermined pressure is applied to obtain a resin molded product with a predetermined shape determined by the two molds. A plasticizing section (I) consisting of linearly arranged plasticizing section (I), and a forming cylinder and a second forming mold placed parallel or almost parallel to this plasticizing section (I), arranged linearly. a pressure molding section (II); a preforming section that can contact the nozzle of the plasticizing section (I); and a first molding unit that is combined with the second molding die of the pressure molding section (II). A mold is provided on the base, and a transfer unit (III) for conveying the preform preformed in the preforming part to the cavity of the first molding mold is pressed with the plasticizing part (I). A plastic molding device characterized in that it is provided so as to move at a right angle or approximately at a right angle to the molding section (II). 2. In claim 1, the plasticizing section (I) and the pressure forming section (II) are arranged vertically or almost vertically, and the transfer unit (III) is arranged horizontally or almost horizontally. Characteristic plastic molding equipment. 3. Put the molten resin into the cavity of the first mold,
Later, the protrusion of the second molding die is inserted into this cavity and a predetermined pressure is applied to obtain a resin molded product with a predetermined shape determined by the two molds. The plasticizing part (
I), a pressure molding section (II) consisting of a molding cylinder and a second molding die, a preforming section capable of contacting the nozzle of the plasticizing section (I), and the pressure molding section A first molding mold to be combined with the second molding mold of (II) is provided on the base, and the preformed product preformed in the preforming section is placed in the cavity of the first molding mold. A transfer unit (III) for conveying is provided, and this transfer unit (III) performs the preforming process and the ejection of the molded finished product by interacting with the other preforming section (I) and the pressure molding section (II). , or a step of transporting the preform above the first mold and a step of transporting the ejected finished molded product to the outside, or a step of dropping the preform into the cavity of the first mold and the finished molded product. A plastic molding method that performs the extraction process at the same time. 4. In claim 1, the preformed part (I) and the pressure-formed part (II) are provided on one metal pedestal, and the space between the preformed part (I) and the pressure-formed part (II) of this pedestal is provided. Plastic molding equipment equipped with a heat shield. 5. The plastic molding apparatus according to claim 4, wherein the heat shielding portion is formed by a slit. 6. Preform the molten resin in the preforming part (I), put the preformed product into the cavity of the first molding die in the pressure molding part (II), and later add a second mold to this cavity. Insert the protrusion of the mold for molding No. 2, apply a predetermined pressure,
A transfer unit (III) is used to obtain a resin molded product with a predetermined shape determined by the two molds, and transfers the preform molded in the preforming section (I) to the pressure molding section (II). The transfer jig is provided with a preform cavity and a molded product receiving part in accordance with the distance L between the preform part (I) and the pressure forming part (II), A transfer jig characterized in that the jig is moved with a stroke of the interval L. 7. According to claim 6, the transfer jig is formed from a flat plate, and an escape hole is provided between the preforming cavity and the molded product receiving part to allow insertion of the second molding die. Transfer jig. 8. The transfer jig according to claim 6, characterized in that the transfer jig is composed of an endless chain or belt, and preform cavities and molded product receivers are provided alternately at each interval L. . 9. The transfer jig according to claim 6, wherein the nozzle side end of the preforming cavity has a smaller diameter than the other end. 10. In claim 6, the transfer jig is movable while being guided by the outer peripheral upper surface of a cylinder horizontally arranged on the base, and the lower opening of the preforming cavity is closed with the upper surface of this cylinder, so that the preforming is possible. Preforming or transfer jig characterized by: 11. The preforming or transfer jig according to claim 10, wherein the upper surface of the cylinder is flat.