JPH07329101A - Method of injection molding and apparatus therefor - Google Patents

Abstract

PURPOSE:To reduce mold cost and a storage space for molds by using commonly a part of the molds in an injection molding machine in a fore step and an injection molding machine in an aft step. CONSTITUTION:In an injection molding method wherein molding is repeated to obtain a single molded product by using two vertical type injection molding machines A, B to successively carry out injection molding, and in the case where a shape of a cavity of a part of molds 300 necessary for the vertical type injection molding machine B in an aft step is equal to a shape of a cavity of a part of molds 30 in the vertical type injection molding machine A in a fore step, a fixed side template 37 which is a part of the molds 30 is removed from other parts of molds 30 after finishing injection molding by the vertical type injection molding machine A in the fore step and transferred to the vertical type injection molding machine B in the aft step to be coupled thereto, thus using the same template at the time of injection molding in the aft step. In this way, by using commonly a part of the molds, mold cost and a storage spece for the molds can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding method for obtaining a single molded product by stacking a plurality of moldings by sequentially performing injection molding using a plurality of injection molding machines each having an injection device and a mold. , And its device.

[0002]

2. Description of the Related Art Conventionally, for example, in a two-material injection molding apparatus of this type, a molded product is first injection-molded by an injection molding machine at a first stage, and this primary molded product is then used as a mold part of an injection molding machine at a second stage. After being transferred, secondary injection molding is carried out here, and molding is repeated to obtain a molded product as a final product. This molding apparatus, for example, obtains a molded product having a two-layer structure. Therefore, in the former stage injection molding machine and the latter stage injection molding, even if some cavities of the mold have the same structure, They did not share a part of the mold and each had a set of molds. This is because part of the mold has a structure that cannot be removed from other members (parts).

[0003]

SUMMARY OF THE INVENTION The above-mentioned prior art is characterized in that a front-stage injection molding machine and a rear-stage injection molding machine are
Even though some cavities of the mold have the same structure, each mold has one set of molds, so the cost is increased by the expensive mold and a large storage space is required. However, there is a problem that it is uneconomical.

The present invention has been made in view of the above-mentioned problems of the prior art, and a part of the mold is shared by the injection molding machine of the first stage and the injection molding machine of the second stage, thereby making the mold An object of the present invention is to provide an injection molding method and an injection molding device that reduce costs and storage space.

[0005]

A method of the present invention for achieving the above object is to perform a single injection molding by successively performing injection molding using a plurality of injection molding machines. In the injection molding method for obtaining, if the shape of a part of the cavity of the mold required for the subsequent injection molding is the same as the shape of a part of the cavity of the mold of the former injection molding machine, After the completion of injection molding, a part of the mold is transferred to the latter-stage injection molding machine and incorporated therein, and injection molding is performed by the latter-stage injection molding machine.

Further, an injection molding apparatus for carrying out the above method is equipped with a plurality of injection molding machines, and injection molding is sequentially carried out by each injection molding machine, so that a plurality of moldings are overlapped to form a single molded product. In the injection molding apparatus for obtaining the above, a part of the mold forming the cavity space of the mold of each injection molding machine is attachable to and detachable from other members of the mold. Positioning means for positioning a part of the mold forming the cavity space of the mold with respect to other members of the mold, and a cavity shape of a part of the mold required for a subsequent injection molding machine Is equal to the cavity shape of a part of the mold of the former injection molding machine, a part of the mold of the former injection molding machine is removed from the other members of the mold, and the mold of the latter injection molding machine is removed. And a mold transfer means for transferring and assembling to the mold part. The one in which the features. Also,
The mold transfer means removes a part of the mold of the subsequent injection molding machine from the other members of the mold and transfers it to the mold part of the injection molding machine of the previous stage to be assembled, or each injection molding machine. Is a vertical injection molding machine. Further, the positioning means is a pin projectingly provided on another member of the mold, and the mold transferring means is a cylinder for protruding a part of the mold to separate from the other member, and an elevating means. And a slide mechanism provided on the table for mounting and sliding a part of the mold separated by the cylinder. And
A two-material molding machine in which two injection molding machines are arranged side by side, each mold is a mold with a three-plate structure, and an intermediate plate as a part of the mold is the other one. In order to attach a molded product or a runner portion to a part of the mold at the time of mold opening of the mold or a mold that is detachable from the member of the former stage, The ejector mechanism may be provided.

[0007]

In the method of the present invention constructed as described above,
First, a primary molded product is injection-molded by a mold of an injection molding machine in the preceding stage, and then the mold is opened. After that, a part of the mold (cavity block) that can be shared with the mold of the subsequent stage and holds the primary molded product is removed from other members by the mold transfer means, and the part of the injection molding machine of the subsequent stage is removed. It is transferred to the mold and used as a part of the latter mold. Then, after the die of the latter stage is clamped, the first molded product is subjected to the second injection molding by the latter injection molding machine to obtain the final molded product.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings, taking a two-material injection molding apparatus equipped with two injection molding machines as an example. First, a vertical injection molding machine to which the present invention is applied will be described. 1 is a front view of a vertical injection molding machine A to which the present invention is applied, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a top view of FIG.

As shown in FIGS. 1 to 3, reference numeral 1 is a machine frame having a substantially box-like shape with a rectangular cross section. The machine frame 1 has upper horizontal frames 2 and lower horizontal frames. The center of the frame 2 is divided vertically by a pair of support frames 3. A mold clamping side plate 5 is fixed to the upper part of the machine frame 4a above the machine frame 1 which is divided, and a mold clamping cylinder 6 driven by air pressure is fixed to the upper surface of the mold clamping side plate 5. The mold clamping side plate 5 and the fixed platen (fixed platen) 8 including the fixed side mold 7 are connected to each other.
Each of them is connected by a book tie rod 9. Also,
A movable platen (movable platen) 12 supported by four tie rods 9 so as to be vertically movable is provided between the mold clamping side plate 5 and the fixed platen 8. The movable platen 12 has a mold clamping side plate. A cylinder rod 10 of a mold clamping cylinder 6 penetrating through the center of 5 is connected, and a movable side mold 11 is provided. With these, mold clamping device X
Is configured. Through holes 13 and 14 are formed in the centers of the stationary mold 7 and the stationary platen 8, respectively. The fixed mold 7 and the movable mold 11 constitute a mold 30 (see FIG. 4).

Reference numeral Y is an injection device, and the fixed platen 8 and the lower machine frame 4b are connected by four guide support rods 15. Between the fixed platen 8 and the machine frame 4b, an arrangement plate 18 and a motor plate 2 which will be described later are supported by the four guide support rods 15 so as to be vertically movable.
3 is provided. Two nozzle touch cylinder 16
Are fixed to both ends of the arrangement plate 18, and each cylinder rod 17 of each nozzle touch cylinder 16 is fixed to both ends of the fixed platen 8. On the other hand, the heating cylinder 20 having the injection nozzle 19 at the center is installed on the arrangement plate 18, and the injection nozzle 19 of the heating cylinder 20 is located toward the through hole 14 of the fixed platen 8. By the vertical movement of the cylinder rod 10 of the mold clamping cylinder 6 described above, the movable mold 11 of the movable platen 12 is brought into pressure contact with the fixed mold 7 of the fixed platen 8 and the fixed mold provided on the fixed platen 8. Through hole 13 that penetrates 7
Then, the injection nozzle 19 of the heating cylinder 20 containing the molten resin therein is press-contacted and inserted by the nozzle touch cylinder 16, and the mold clamping and the injection can be performed from above and below.

An injection cylinder 21 is fixed to both sides of the lower surface of the arrangement plate 18, and each cylinder rod 22 of the injection cylinder 21 is fixed to an upper surface of a motor plate 23. A screw drive motor 24 is installed on the lower surface of the motor plate 23, and a rotary shaft 25 of the screw drive motor 24 is mounted on a screw (not shown) in the heating cylinder 20.
Are linked to. That is, the four guide support rods 1
5, the arrangement plate 18, the motor plate 23, and the support plate 26 that are vertically movable are fixed to the fixed platen 8 by fixing the cylinder rod 17 of the nozzle touch cylinder 16 attached to the arrangement plate 18, and the cylinder rod 17 is extended. As a result, they will move up and down together.
Reference numeral 27 is a hopper for supplying the resin material to the heating cylinder 20, reference numeral 28 is a control panel for setting conditions and control of injection molding, and reference numeral 29 is for setting the pressure of compressed air supplied to the mold clamping cylinder 6. This is a pneumatic valve. Although not shown, this injection molding machine is equipped with a product take-out robot.

Next, the detailed structure of the mold 30 will be described. As shown in FIG. 4, the mold 30 has a known three-plate structure, and includes a fixed mold plate 37 as a lower mold and a movable mold 11 as an upper mold. Fixed side mold 7
Is a fixed side mounting plate 35 fixed to the fixed platen 8,
Stripper plate 36 and one cavity 45
And a fixed side template (intermediate plate) 37 as a cavity block in which the movable side mold 11 is fixed to the movable platen 12, a spacer block 40, a receiving plate. 39, and the movable side mold plate 37 in which the other cavity 46 is formed.

Each of the cavities 45 and 46 constitutes a cavity space for forming the primary molded product 47, and the fixed side mold plate 3 is formed.
7 and the movable mold plate 38 form a cavity block.
The fixed-side mold plate 37, which is a part of the mold 30, is detachable from the stripper plate 36, and is also used as a part of a mold at a later stage, which will be described later. The reference numeral 31 indicates a parting line of the mold 30.

The sprue bush 34 is provided in the injection nozzle 19
The nozzle touch portion 33 (see FIG. 1) is in pressure contact with the sprue 32a, and the sprue 32a communicates with the cavity space via a sprue 32b formed on the stationary mold plate 38. Upper and lower ejector plates 42, 43 driven by driving means (not shown)
Includes a plurality of ejector pins 44 for ejecting the molded product.
Are provided so as to form an ejector mechanism. Among the items described above, the fixed side mold plate 37 which is a part of the mold 30 is detachable from the stripper plate 36, and is not used as a part of the mold in the subsequent stage. , Is a known technique.

FIG. 5 is a view showing the detailed structure of the mold of the injection molding machine at the latter stage, showing the cavity 460 of the movable side mold plate 380.
4 has the same structure except that the shape is different from that of FIG. 4, and the fixed-side mold plate 37 used is the mold 30 (see FIG. 4) of the preceding stage.

Next, the features of the present invention will be described in detail. FIG. 6 is a front view of a mold part of a two-material injection molding apparatus of the present invention, FIG. 7 is a side view of a mold part of an injection molding machine in a front stage, and FIG. 8 is a side view of a mold part of an injection molding machine in a rear stage. Is.

First, as shown in FIG. 6, in the two-material injection molding apparatus of the present embodiment, a front vertical injection molding machine A and a rear vertical injection molding machine B are installed side by side, and in between, the front vertical injection molding machine A is installed. After the injection molding by the vertical injection molding machine A, the mold transfer device 50 for transferring the fixed side mold plate 37, which is a part of the cavity block, to the mold part of the vertical injection molding machine B in the subsequent stage and incorporating it. It is provided. In the case of this embodiment, the fixed-side mold plate 37 is a common part for the front and rear molds. The die transfer device 5
0 is the direction of arrow X and arrow Z due to the lifting cylinder 51.
Table 52 that is moved up and down in the direction, and a slide for mounting the fixed-side mold plate 37 provided on the table 52 and sliding the fixed-side mold plate 37 in the horizontal plane arrow Y direction and the counter arrow Y direction. It is composed of a mechanism 56 and a die ejection cylinder 53 (see FIG. 8) described later.

As shown in FIG. 7, in the mold of the vertical injection molding machine A in the preceding stage, the fixed-side mold plate 37 is positioned in the horizontal plane by a plurality of positioning pins (not shown) described later. These configurations are also adopted in the mold of the vertical injection molding machine A in the preceding stage.

As shown in FIG. 8, when the mold of the vertical injection molding machine B at the subsequent stage is clamped, the fixed mold plate 370, which is a part of the cavity block, is projected on the movable mold 110. The positioning pin 55 and the positioning pin 54 projecting from the movable side mounting plate 350 are positioned in the horizontal plane. Then, after the mold 300 is opened, a plurality of mold ejecting cylinders 53 provided on the fixed platen 80.
Thus, the fixed-side mold plate 370 can be lifted and separated from other mold parts. These configurations are also adopted in the mold of the vertical injection molding machine A in the preceding stage.

Next, the operation of the two-material injection molding apparatus of this embodiment, that is, the injection molding method will be described. As shown in FIGS. 4 and 7, first, the vertical injection molding machine A in the preceding stage is used.
The mold 30 is used to mold a primary molded product 47 as a gear body, and the mold 30 is opened as shown in FIG. At the time of this mold opening, the plurality of ejector pins 44 are driven, so that the primary molded product 47 and its runner portion are pressed against the fixed-side mold plate 37 and adhere thereto.

Then, the die ejection cylinder 53 (see FIG. 8)
The fixed-side mold plate 37 holding the primary molded product 47 is lifted by driving (see FIG. 4), and thereafter, the lifting cylinder 51 is driven, so that the table 52 in the standby position is indicated by the arrow X in advance. Thus, it is joined below the fixed-side template 37. Here, the lifting cylinder 51
When the table 52 is further driven, the fixed side template 37 is supported by the slide mechanism 56. Here, the slide mechanism 56 transfers the fixed-side mold 37 to the mold part in the subsequent stage as shown by the arrow Y, and positions it above the rod tip of the mold ejecting cylinder 53 (see FIG. 8).

Thereafter, the table 52 is lowered by the lifting cylinder 51, so that the fixed mold 37 is mounted on the tip of the rod of the mold ejecting cylinder 53 (see FIG. 8). Thereafter, the rod of the die ejecting cylinder 53 (see FIG. 8) is contracted, so that the fixed die 37 is guided by the positioning pin 54 and descends as shown by an arrow Z, and is set on the spacer block 360. . During this time, the table 52 is moved to the reference numeral 52a by the lifting cylinder 51.
Come to the standby position indicated by. After that, the mold 300 in the latter stage is clamped and the secondary injection molding is sequentially performed to obtain a secondary molded product 470 (see FIGS. 5 and 8) having a flange portion. When the mold 300 of the latter stage is closed, the positioning pin 55
Is inserted into the fixed-side template 37. During the secondary injection molding, the table 52 moves to the standby position. Of course, if necessary, the fixed side mold 37 is moved from the vertical injection molding machine B to the preceding vertical injection molding machine A by performing the reverse operation to the above.
Can be transferred to.

In the above embodiment, the vertical injection molding machine A,
Needless to say, B functions as a single molding, that is, a single-material injection molding machine other than the multi-stage molding. In the above embodiment, the two-material injection molding apparatus provided with two injection molding machines has been described as an example, but the present invention is not limited to this, and the present invention may be applied to a horizontal injection molding machine. The number of injection molding machines is not limited to two. Further, although a gear is shown as an example of the molded product, a molded product having a two-layer structure, a flange-shaped molded product and the like are also available.

[0024]

Since the present invention is configured as described above, it has the following effects. In the invention of the method, the mold cost and the storage space are significantly reduced by sharing a part of the mold between the injection molding machine of the first stage and the injection molding machine of the second stage. Since the invention of the apparatus can surely perform the above method and is suitable for automation, productivity is improved.

[Brief description of drawings]

FIG. 1 is a front view of a vertical injection molding machine to which the present invention is applied.

FIG. 2 is a side view of FIG.

FIG. 3 is a top view of FIG.

FIG. 4 shows a detailed structure of the former die in a clamped state,
It is the figure which made most part the cross section.

FIG. 5 shows a detailed structure of a die at a latter stage in a clamped state,
It is the figure which made most part the cross section.

FIG. 6 is a front view of a mold part of the two-material injection molding apparatus of the present invention.

FIG. 7 is a side view of a mold part of the injection molding machine in the first stage.

FIG. 8 is a side view of a mold part of a subsequent injection molding machine.

[Explanation of symbols]

 A Vertical injection molding machine in the first stage B Vertical injection molding machine in the second stage X Clamping device Y Injection device 1 Machine frame 2 Both horizontal frames 3 Support frame 4a Upper machine frame 4b Lower machine frame 5 Clamping side plate 6 Clamping cylinder 7 Fixed Side Mold 8 Fixed Platen 9 Tie Rod 10 Cylinder Rod 11 Movable Side Mold 12 Movable Platen 13, 14 Through Hole 15 Guide Support Rod 16 Nozzle Touch Cylinder 17 Cylinder Rod 18 Arrangement Plate 19 Injection Nozzle 20 Heating Cylinder 21 Injection Cylinder 22 Cylinder rod 23 Motor plate 24 Screw drive motor 25 Rotating shaft 26 Support plate 27 Hopper 28 Control panel 29 Pneumatic valve 30 Mold of injection molding machine in the previous stage 31 Parting line 32a, 32b Sprue 33 Nozzle touch part 34 Sprue bush 35 Fixed Mounting plate 36 Stripper plate 37,370 Fixed-side mold plate 38 Movable-side mold plate 39 Receiving plate 40 Spacer block 41 Movable-side mounting plate 42 Upper ejector plate 43 Lower ejector plate 44 Ejector pin 45, 46 Cavity 47 Primary molding 50 Gold Mold transfer device 51 Lifting cylinder 52 Table 53 Mold ejection cylinder 54, 55 Positioning pin 56 Sliding mechanism 300 Mold of injection molding machine in the latter stage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Furukawa 6-18-12 Wakamiya, Ichihara City, Chiba Prefecture

Claims (8)

[Claims] 1. An injection molding method for obtaining a single molded product by stacking a plurality of moldings by sequentially performing injection moldings by using a plurality of injection molding machines. If the shape of a part of the cavity of the mold is equal to the shape of the cavity of a part of the mold of the injection molding machine of the former stage, after completion of injection molding by the injection molding machine of the former stage, part of the mold is An injection molding method, characterized in that it is transferred to an injection molding machine and incorporated therein, and injection molding is performed by an injection molding machine at a subsequent stage. 2. An injection molding apparatus comprising a plurality of injection molding machines, wherein each injection molding machine sequentially performs injection molding to obtain a single molded article by stacking a plurality of moldings. A part of the mold forming the cavity space of the mold is detachable from the other members of the mold, and one of the molds forming the cavity space of the mold of each injection molding machine. The positioning means for positioning the part with respect to the other members of the mold, and the cavity shape of a part of the mold required for the injection molding machine of the latter stage is one of the molds of the injection molding machine of the former stage. Mold for removing the part of the mold of the former stage injection molding machine from the other members of the mold, and transferring and assembling it to the mold part of the latter stage injection molding machine when the cavity shape of the second part may be the same. An injection molding apparatus comprising: a transfer unit. 3. The mold transfer means removes a part of a mold of a subsequent injection molding machine from other members of the mold, transfers the mold to a mold part of the front injection molding machine, and incorporates it. Claim 2
The injection molding apparatus according to. 4. The injection molding apparatus according to claim 2, wherein each injection molding machine is a vertical injection molding machine. 5. The positioning means is a pin projecting from another member of the mold, and the mold transferring means projects a part of the mold to separate it from the other member. And a table driven up and down by the lifting means,
5. A slide mechanism provided on the table for mounting and sliding a part of the mold separated by the cylinder.
The injection molding apparatus according to any one of 1. 6. The injection molding apparatus according to claim 2, wherein the injection molding apparatus is a two-material injection molding apparatus in which two injection molding machines are arranged side by side. 7. The mold according to claim 2, wherein the mold has a three-plate structure, and the intermediate plate as a part of the mold is detachable from other members. The injection molding apparatus according to. 8. A mold of an injection molding machine at a first stage is provided with an ejector mechanism for attaching a molded product or a runner portion to a part of the mold when the mold is opened. The injection molding apparatus according to any one of 2 to 7.