JPH07227875A - Injection molding machine - Google Patents

Abstract

PURPOSE:To provide an injection molding machine for molding a material of different quality (or different color) in which the replacement of a mold is easy and also the setting of a versatile release device is easy. CONSTITUTION:A nozzle 111 is bonded with a mold 20 in the horizontal direction in a main injection unit 11. A nozzle 121 of an injection unit 12 is bonded with a sprue of a mold 20 by the oblique angle theta of 25 deg. or smaller in the mold opening direction P. A nozzle touch face of the sprue with which the nozzle 121 of the injection unit 12 is inclined to the perpendicular line by the same oblique angle theta as that of the nozzle 121, and disposed on a protruding section 23 of a fixed main mold 22. The oblique angle is preferably set at 5 deg.-15 deg., and a runner for transferring a sub-material is preferably a hot runner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding machine for injection-molding products composed of resins of different colors and materials, and particularly to use a large number of general-purpose members without taking up much space. The present invention relates to an injection molding machine capable of performing.

[0002]

2. Description of the Related Art An injection molding machine for products composed of resins of different colors and materials requires a plurality of injection units and a resin passage of a mold, which makes the structure complicated and cannot use general-purpose members. In addition, there are many restrictions on the efficiency of production.
The injection molding machine 90 for molding the different materials (or different colors, the same applies hereinafter) includes a main injection unit 91 as shown in FIG.
And a sub-injection unit 92, a mold having a fixed main mold 931 and a movable main mold 932, and a mold clamping device 95.

The fixed main mold 931 and the movable main mold 932
Are attached to the fixed die plate 951 and the movable die plate 952, respectively. Then, the main injection unit 91 supplies the main material by adhering the nozzle 911 to a sprue (not shown) of the mold in a direction parallel to the mold opening direction P, as shown by the arrow in the figure, and joining them. On the other hand, the sub-injection unit 92 is arranged right above the mold and has the nozzle 9
21 is brought close to and joined to a sprue (not shown) of a mold from an L direction perpendicular to the mold opening direction P, and a sub material is supplied.

Further, as another example of the injection molding machine 90, there is one in which a sub injection unit 94 is arranged obliquely upward as shown in FIG. The sub-injection unit 94 starts from its stop position in the direction M parallel to the mold opening direction P.
1 is extended, and then the nozzle 941 is rotated in the R direction shown in the figure to join the nozzle to the sprue of the mold. Therefore, the tip portion of the nozzle 941 has a bent shape.

The reference numeral 942 in the figure indicates a nozzle 941.
Is a cylinder for rotating the R in the R direction. The nozzle 941 has a flat nozzle (a nozzle having a flat joint surface) because a spherical nozzle cannot be used because of its structure.

[0006]

[Problems to be Solved] However, the conventional injection molding machine for molding different materials has the following problems. In the injection molding machine of the first type shown in FIG. 3, since the sub-injection unit 92 occupies the upper space of the mold, the mold cannot be exchanged (setup change) from above using a crane. Therefore, it is necessary to replace the mold from the lateral direction, which requires time and effort for setup.

Further, since the sub-injection unit 92 is provided on the upper side, there is a problem that the unloader cannot be set on the upper part and the unloader must be a special one having no versatility. On the other hand, in the second type of injection molding machine shown in FIG. 4, the sub-injection unit 94 when not in operation is positioned in the diagonal direction of the mold (after rotating the nozzle 941 in the R direction in FIG. 4). , In a position retracted in the M direction), it is possible to replace the mold from above using a crane.

However, since the auxiliary injection unit 94 operates as described above, the space occupied by the movement (the range of movement in the R direction and the M direction in FIG. 4) is wide, and is similar to that of the first type injection molding machine. In addition, it is difficult to install a normally used unloader. Further, since the nozzle 941 of the second injection molding machine is a flat nozzle, there is a problem that resin leakage easily occurs in the state of being joined with the sprue.

Further, the sub-injection unit 94 needs to control the transverse movement in the M direction and the rotational movement in the R direction with high accuracy. This is because if the control accuracy is poor, it will not bond properly to the nozzle touch surface of the sprue, resulting in resin leakage from the nozzle. Further, the cylinder 942 is required for the operation in the R direction, and the nozzle 941 also has a special shape, and the entire structure is complicated, delicate and expensive.

In view of the above problems of the conventional injection molding machine, the present invention makes it easy to set up the mold, install a general-purpose take-out machine, and inexpensively for different materials (or An object is to provide an injection molding machine for (different color) molding.

[0011]

The present invention is an injection molding machine for injection-molding products composed of resins of different colors and materials, in which the main injection unit for injecting the main material is a mold. The sprue is configured so that the nozzle is brought close to and joined to the sprue in a direction parallel to the mold opening direction. The nozzle touch surface of the sprue that receives the sub-material from the sub-injection unit is configured so that the nozzle is brought into close proximity to the sprue and is joined to the sprue. Injection molding for dissimilar materials, characterized in that it is formed on the projection and is inclined with respect to the vertical line by the same angle θ as the inclination angle θ of the nozzle of the sub-injection unit. Located in the molding machine.

What is most noticeable in the present invention is that the sub-injection unit brings the nozzle close to and joins the sprue at an inclination angle θ of 25 ° or less with respect to the mold opening direction, and fixes the nozzle touch surface of the sprue. The main feature is that it is formed on the upper projection of the mold and is arranged so as to be inclined by the same angle θ as the above-mentioned inclination angle θ.

The inclination angle θ and the angle θ of the nozzle touch surface are preferably 5 ° to 15 °. This is because if the inclination angle θ is smaller than 5 °, the horizontal component force (force in the mold opening direction) acting on the protrusion of the fixed main mold becomes large, and the fixed main mold is deformed. On the other hand, when the inclination angle θ exceeds 15 °, the height of the sub-injection unit (diagonally upward height)
Is large, it occupies a lot of space above and considerably restricts the degree of freedom in designing the installation of the unloader.

The mold runner for transferring the auxiliary material is
A hot runner is preferred. This is because a hot runner can prevent burrs from the parting line.

In the above description, the inclination angle θ of the nozzle is the angle formed by the axis of the nozzle (injection direction) with respect to the horizontal plane. The nozzle touch surface is a surface of the sprue that is joined to the nozzle and is formed in a direction perpendicular to the resin inflow direction. The nozzle touch surface that is close to the horizontal direction is generally vertical, and this state is referred to as a zero tilt angle in the present application.

[0016]

In the injection molding machine according to the present invention, the nozzle touch surface is formed on the protrusion which is provided above the fixed main mold (in the direction perpendicular to the mold opening direction P). Therefore, the sub-injection unit can extend the nozzle obliquely from above and join the nozzle close to the nozzle touch surface (see FIG. 1).

Since the inclination angle θ (FIG. 2) for bringing the nozzle close to the nozzle touch surface and the inclination angle θ ′ (FIG. 2) of the nozzle touch surface are equal (θ = θ ′), the two are exactly joined. (See FIG. 2). Therefore,
Unlike the conventional second type injection molding machine, resin leakage does not occur from the end of the nozzle.

Further, since the nozzles come close to each other with a small inclination angle of 25 ° or less, the space above the die occupied by the operation of the nozzle can be stopped within a narrow range (as described above). In addition, the inclination angle is more preferably 15 ° or less). Therefore, the mounting machine or the like can be installed above the mold without receiving a large restriction.

By retracting the nozzle of the sub-injection unit, the space above the mold is opened, so that the mounting machine installed above the mold can be operated without any trouble. In addition, the molds can be exchanged from above using a crane, which facilitates setup change.

Further, it is easy to provide the above-mentioned projection above the fixed main mold, and it is similarly easy to form the sprue (including the nozzle touch surface) on the projection. Therefore, the mold can be manufactured at a low cost by slightly changing the general-purpose mold, and can correspond to many types and shapes of molds.

The sub-injection unit may be a normal injection unit that expands and contracts the nozzle in only one direction, and is simply installed at an inclination angle θ. Therefore, the injection molding machine of the first type (FIG. 3). And the cost is substantially the same as that of the injection molding machine of the second type (FIG. 4). As described above, according to the present invention, it is possible to provide an injection molding machine for molding different materials (or different colors), in which the setup of the mold can be easily changed, a general-purpose take-out machine can be easily installed, and the cost is low. can do.

[0022]

EXAMPLE An injection molding machine according to an example of the present invention
This will be described with reference to FIGS. This example is an injection molding machine 1 for injection-molding a product composed of resins of different colors and materials as shown in FIG. In the injection device 10, the main injection unit 11 that injects the main material is provided with a mold 20.
The nozzles 111 are arranged close to and joined to a sprue (not shown) in a direction parallel to the mold opening direction P.

On the other hand, a sub injection unit 1 for injecting a sub material
As shown in FIG. 2, the nozzle 2 is configured so that the nozzle 121 is brought close to the sprue 24 and joined to the sprue 24 at an inclination angle θ of 25 ° or less with respect to the die opening direction P of the die 20.

The nozzle touch surface 241 of the sprue 24 that receives the auxiliary material from the auxiliary injection unit 12 has the protrusion 2 of the fixed main mold 22 protruding in the direction perpendicular to the mold opening direction P.
3 and is disposed on the projection 23 with an inclination angle θ ′ of the nozzle 121 of the auxiliary injection unit 12 and the same angle θ ′ with respect to the vertical line. The inclination angles θ and θ ′ are 15 °. Further, the runner 2 of the fixed main mold 22 for transferring the auxiliary material injected from the auxiliary injection unit 12
5 is a hot runner.

A supplementary explanation will be added to the injection molding machine 1. The main injection unit 11 has a base 4 as shown in FIG.
It is installed horizontally on top of the No. 1 and softens the main material charged from the hopper 112 to an appropriate state and injects it from the nozzle 111 into the sprue of the mold. The nozzle 111 is driven by an actuator (not shown), extends in the horizontal direction (= mold opening direction P), and is joined to the nozzle touch surface of the sprue.

On the other hand, the sub-injection unit 12 includes the mold clamping device 3
It is installed on the inclined plate 42 fixed to the fixed die plate 31 of 0. The inclined plate 42 forms an angle θ with respect to the horizontal plane.
Only the nozzle 121
Is expanded and contracted in the direction parallel to the inclined plate 42.

The die 20 has a fixed main die 22 fixed to the fixed die plate 31 and a movable main die 21 fixed to the movable die plate 32. In FIG. 1, reference numerals 311 and 321 are mounting plates for the main molds 21 and 22. The fixed main mold 22 has a protrusion 23 protruding above the fixed die plate 31, and the protrusion 23 has
As shown in FIG. 2, a sprue 24 and a nozzle touch surface 241 that are joined to the nozzle 121 of the sub injection unit 12 are formed.

On the nozzle touch surface 241, the nozzle 121
A concave portion having substantially the same shape and size as the circular convex portion is formed. The nozzle touch surface 241 is formed on the side surface of the protrusion 23 so as to have the same angle θ ′ as the above-mentioned inclination angle θ with respect to the vertical line, and the sprue 24 has the same inclination angle θ as the nozzle 121. There is. The sprue 24 and the runner 25 following it are formed on a hot runner block 26, and the protrusion 23 is an extension of the hot runner block 26.

Next, the function and effect of this example will be described.
The sub-injection unit 12 of the injection molding machine 1 of this example includes a mold 20.
The nozzle 121 is extended from the side of the
It can be joined exactly to 41. Then, when the nozzle 121 is retracted, an upper space of the mold 20 becomes an open space, so that a normal take-out machine or the like can be freely set here.

Further, if the nozzle 121 is retracted, the mold 20 can be replaced from above, so that a crane or the like can be used, which is extremely easy. Further, since the runner 25 is a hot runner, the auxiliary material can be transferred into the cavity even if the injection pressure of the auxiliary injection unit 12 is low. Moreover, since the injection pressure may be low, the force in the mold opening direction is not excessively applied to the fixed main mold 22.

The nozzle touch surface 241 is the nozzle 12
1 is directed in the direction in which they are close to each other, and the concave portion thereof is formed to have substantially the same shape and size so that the concave portion can be closely joined to the convex portion of the nozzle 121. Therefore, resin leakage is unlikely to occur. The sub-injection unit 12 is an inexpensive injection unit in which a normal injection unit is installed on the inclined plate 42.

Further, the projections 23 and the like provided on the fixed main mold 22 are merely simple design changes to the normal mold,
It does not cost much more than general-purpose dies, and can be applied to most dies. Therefore, the injection molding machine 1 of this example can significantly reduce the cost as compared with the conventional second type injection molding machine (FIG. 4).

As described above, according to this embodiment, it is easy to set up the mold, the general-purpose take-out machine can be easily installed, and the injection molding for different materials (or different colors) is inexpensive. Machine can be provided.

[Brief description of drawings]

FIG. 1 is a front view of an injection molding machine according to an embodiment.

FIG. 2 is an enlarged cross-sectional view of a main part when the nozzle of the auxiliary injection unit is sprue-joined in the example.

FIG. 3 is a front view of a conventional injection molding machine for molding different materials.

FIG. 4 is a front view of another conventional injection molding machine for molding different materials.

[Explanation of symbols]

 1. ． ． Injection molding machine, 11. ． ． Main injection unit, 111, 121. ． ． Nozzle, 12. ． ． Secondary injection unit, 20. ． ． Mold, 22. ． ． Fixed main type,

Claims (3)

[Claims] 1. An injection molding machine for injection-molding products composed of resins of different colors and materials, wherein in the injection device, the main injection unit for injecting the main material is parallel to the mold opening direction of the mold. The nozzles are arranged so that the nozzles are brought close to the sprue from different directions and joined. On the other hand, the sub-injection unit that injects the sub-materials has the nozzles in the sprue with an inclination angle θ of 25 ° or less with respect to the die opening direction. The nozzle touch surface of the sprue configured to be brought into close contact with each other and to receive the sub-material from the sub-injection unit is formed on the protrusion of the fixed main die protruding in the direction perpendicular to the die opening direction. At the same time, the injection molding machine is arranged so as to be inclined to the vertical line by the same angle θ as the inclination angle θ of the nozzle of the sub injection unit. 2. The injection molding machine according to claim 1, wherein an inclination angle θ at which the sub injection unit joins the nozzle to the sprue and the angle θ of the nozzle touch surface are 5 to 15 °. 3. The injection molding machine according to claim 1 or 2, wherein the mold runner for transferring the auxiliary material injected from the auxiliary injection unit is a hot runner.