JPH0216845Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a mold fixing structure in a horizontal clamping, vertical injection type injection molding apparatus.

[Prior art]

Traditionally, many injection molding machines, such as die casting machines and plastic injection molding machines, had the mold clamping direction and the injection direction in the same direction, but in recent years, injection molding machines such as molds clamped horizontally into the cavity of the mold from below have been introduced. Horizontal mold clamping and vertical casting type injection molding equipment that injects molten metal or resin has been developed.

For example, in the case of a die-casting machine, this type of injection molding equipment has a short length of molten metal in the casting sleeve before injection, which reduces the temperature drop of the molten metal, and a small contact area between the molten metal and air. The amount of cavities caused by gas inside the sleeve is small.
Although this method has many advantages, such as effective pressure transmission because the injection plunger faces the cavity when filling is completed, there were problems with fixing the mold.

In other words, when a fixed mold mounted on a fixed plate and a movable mold mounted on a movable plate are clamped and molten metal is poured into the cavity, the casting force is perpendicular to the direction of action of the clamping force. Since this force acts from below, it may overcome the frictional force between the plate and the mold and between the two molds, causing the mold to shift in the forward direction of the injection plunger.

FIG. 1 is a sectional view of the mold and the casting sleeve showing such a misaligned state, and shows that the fixed mold 3 and the movable mold 4 are separated after the injection plunger 2 has moved forward inside the casting sleeve 1. Molten metal 5 into cavities 3a and 4a
The movable mold 4 is shown displaced upward by the casting force as a result of the casting. This misalignment creates a gap 7 between the casting sleeve 1 and the fixed sleeve 6 on the movable mold 4 side, and there is a risk that the molten metal 5 will spout from this gap, which is extremely dangerous. This has disadvantages in that burrs are formed at the gap 7 and the product is deviated from the dividing plane, resulting in a deterioration in the quality of the product.

[Summary of the idea]

The present invention was developed in view of the above points, and is designed to be used in horizontal mold clamping and vertical casting mold injection molding equipment.
The injection force can be reduced by controlling the upward movement of the base and the movable platen that moves above the base plate from the mold opening position to the mold clamping position by engaging the protrusions and grooves at least in the mold clamping position. The purpose of the present invention is to provide a mold fixing structure for an injection molding device that prevents displacement of a movable mold due to mechanical problems and improves work stability and product quality. Embodiments of the present invention will be described in detail below with reference to the drawings.

〔Example〕

This embodiment shows an example in which the mold fixing structure according to the present invention is implemented in a horizontal mold clamping and vertical casting type die casting machine. 2 is a sectional view taken along the line AA in FIG. 2. In the figure, a die casting machine 11 is equipped with a horizontal mold clamping unit 12 and a vertical casting unit 13. A fixed platen 15 and a fixed platen (not shown) movably fixed to the other end of the machine base 14 are provided. Reference numeral 16 denotes a column that connects the four corners of both fixed plates and is fixed with a nut 17, and this column 16 has a movable plate 18 connected to the fixed plate 1.
The movable platen 18 is supported so as to be movable forward and backward in the direction of distance relative to the movable platen 5, and a toggle mechanism 19 connects the movable platen 18 with a mold clamping cylinder (not shown) on the fixed platen side. 20 is a fixed mold that is mounted on the fixed platen 15 and whose movement in the vertical direction is regulated by a key 21; 22 is a fixed mold that is mounted on the movable platen 18 and has a key 22;
The molds 20 and 22 are movable molds whose movement in the vertical direction is regulated by the movable molds 20 and 22, and the molds 20 and 22 are joined with a dividing surface 23 as a boundary so as to be openable and closable in the horizontal direction.
Both molds 20 and 22 have a cavity 24, a constriction 25 below the cavity 24, and a constriction 25.
Subsequently, a vertical hole 26 opening downward is divided by the dividing surface 23, and the vertical hole 26 is divided by the dividing surface 23.
A fixing sleeve 27, which also has a half-split shape, is fitted into the. 28 is a product extrusion device that extrudes the cast product from inside the cavity 24.

In such a horizontal mold clamping unit 12, by moving a piston rod of a mold clamping cylinder fixed to a fixed platen (not shown) back and forth, the movable platen 18 moves back and forth via a toggle mechanism 19, and both molds 2
0 and 22 mold clamping and mold opening are performed. After the mold is clamped, the molten metal is poured into the cavity 23 by the vertical casting unit 13, which will be described later.
A mold fixing structure is provided to restrict upward movement of the mold. That is, protrusions 18a projecting horizontally are provided on both sides of the lower part of the movable platen 18, while these protrusions 18a are slidably engaged with both sides of the machine base 14 to which the fixed platen 15 is integrally fixed. A matching groove 14a is provided, and the upper surface of the protrusion 18a and the upper surface of the groove 14a are in contact with each other at least at the mold clamping position. This, together with the provision of the keys 21 and 22, restricts the upward movement of the movable platen 18 and both molds 20 and 22 at the mold clamping position. In addition,
With the mold opening operation of the mold clamp, the protrusion 18a moves into the groove 14.
If a enters or exits from the rear end, protrusion 1
Tapered portions are provided on the upper surface and side surfaces of the tip of the protrusion 18a and on the upper surface and side surfaces of the rear end of the groove 14a so that the groove 8a can easily enter the groove 14a. Of course, even when the mold is opened, the protrusion 18
If the groove 14a is provided long enough so that a does not come out of the groove 14a, there is no need to provide this tapered portion.

On the other hand, the frame 29 of the vertical casting unit 13 is
It is erected in a pit 30 provided below the mold clamp to support the end of the machine base 14, and inside this frame 29, four support rods are installed between it and the lower column 16. A cast frame 32 connected at 31 is provided near the bottom of the pit 30. 33 is an injection cylinder rotatably supported on the cast frame 32, and an injection plunger 35 is connected to the piston rod 34 of the injection cylinder 33.
6, and is configured such that the injection plunger 35 is moved up and down by the hydraulic pressure of the injection cylinder 33. Further, the casting sleeve 3 is slidably engaged with the head 35c of the injection plunger 35, which is a plunger tip consisting of a large-diameter cylindrical portion 35a and a tapered or small-diameter cylindrical portion 35b above the large-diameter cylindrical portion 35a.
7 is fixed to the upper end surface, the block 38 has a hole at the lower end engaged with the piston rod 34, and a pair of rams 39 implanted on the upper surface of the injection cylinder 33.
The block 38 is supported by fitting into a ram hole, and the block 38 is moved up and down by pressure oil introduced into a cylinder 40 provided in the block 38 and by the lowering of the piston rod 34. When the block 38 moves up, the casting sleeve 37 and the fixed sleeve 27 are concentrically pressed together, and when the block 38 moves down, both the sleeves 3
7 and 27 are separated. Reference numeral 41 denotes a tilting cylinder pivotally supported on the frame 29 side, and the working end of its piston rod is pivotally connected to the injection cylinder 33. When the block 38 is lowered, both sleeves 37,
By operating the tilting cylinder 41 with 27 spaced apart, the entire vertical casting unit 13 is configured to stand up and tilt between the casting position shown in the figure and the inclined pouring position. ing. 42
is an adjustable stopper that abuts the injection cylinder 33 and restricts the limit of its rotation toward the casting position.

The operation of the die casting machine configured as above will be explained. When the fixed mold 20 and the movable mold 22 are attached to the fixed platen 15 and the movable platen 18, respectively, and the piston rod of the mold clamping cylinder (not shown) is advanced, the movable platen 18, which is in the mold opening position, moves to the toggle mechanism 19. The mold is moved horizontally to the mold clamping position shown in the figure, and mold clamping is performed. At this time, the cavity 24 is accurately joined, and at the same time, the movable platen 1
The protrusion 18a of 8 and the groove 14a of the machine base 14 fit together, and the movable platen 18 is fixed so as not to move in the vertical direction. During this mold clamping, the piston rod 34 of the injection cylinder 33 has been lowered to the position shown in the figure, and the block 38 has been lowered further than the position shown in the figure, and both sleeves 27, 37 are separated, so that the tilting cylinder 41 When the piston rod is moved forward, the entire vertical casting unit 13 is tilted.
After pouring the molten metal into the casting sleeve 37, when the piston rod of the tilting cylinder 41 is moved back, the vertical casting unit 13 stands up as shown in the figure, so that pressure oil is introduced into the cavity 40 of the block 38. Then, the block 38 is raised and the casting cylinder 37 is concentrically pressed against the fixed cylinder 27. After this, when the piston rod 34 of the injection cylinder 33 is advanced, the injection plunger 35
rises, and the molten metal in the casting sleeve 37 is injected into the cavity 24 through the fixed sleeve 27 and the constriction 25. In this case, a large casting force acts on both the molds 20 and 22, but the protrusion 18 of the movable platen 18
a fits into the groove 14a of the machine base 14, and in particular, the upper surface of the protrusion 18a and the upper surface of the groove 14a are in contact with each other, and the keys 21 and 22a are provided, so that the movable platen 18 is moved upward. Therefore, the fixed mold 20 and the movable mold 22 do not become misaligned.

After casting, when the molten metal solidifies and cools, the piston rod 14 and block 38 are lowered, the movable platen 18 is moved to open the mold, and the product is extruded from the movable mold 22 by the product extrusion device 28. Extrusion completes the casting cycle.

Although this embodiment shows an example in which the mold fixing structure according to the present invention is applied to a die-casting machine, it can be similarly applied to a horizontal clamping type or a vertical casting type plastic injection molding machine. Further, in the embodiment described above, the key 21 was provided to prevent the fixed mold 20 from moving upward with respect to the fixed platen 15, but this key 21 was provided with a slightly protruding portion on the upper surface of the fixed mold 20. It may be provided integrally with the fixed platen 15 so that the lower surface of this protrusion presses the upper surface of the fixed mold 20. Furthermore, the protrusion or key may be provided between the movable mold 22 and the movable platen 18.

[Effect of idea]

As is clear from the above explanation, according to the present invention, in an injection molding apparatus of horizontal mold clamping and vertical casting mold,
Protrusions protruding horizontally on both sides of the lower part of the movable platen are provided, and members with grooves in which these protrusions are slidably engaged are provided on both sides of the machine base, and at least in the mold clamping position, the upper surface of the protrusions and the grooves are provided. By forming the mold so that they are in contact with the side surfaces, even if injection is performed from below into the mold cavity after the mold is closed and the injection force acts on the movable mold, the movable mold and the fixed mold will not come into contact with each other. Since there is no misalignment, there is no occurrence of burrs on the mold dividing surface, no spouting of molten injection material, etc., and the quality of the molded product is improved, and work safety can be ensured.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a mold and a casting sleeve of a conventional die-casting machine, and FIGS. 2 and 3 show an embodiment of the mold fixing structure of an injection molding apparatus according to the present invention. FIG. 3 is a vertical cross-sectional view of a die-casting machine that carried out this process, and FIG. 3 is a cross-sectional view along AA of FIG. 2. 11... Die casting machine, 12... Horizontal mold clamping unit, 13... Vertical casting unit, 14... Machine base, 14a... Groove, 15... Fixed plate, 18
...Movable plate, 18a...Protrusion, 20...Fixed mold, 22...Movable mold.

Claims (1)

[Scope of utility model registration request] In a horizontal mold clamping, vertical casting type injection molding device, projections 1 projecting horizontally on both sides of the lower part of the movable platen 18.
8a, and members having grooves 14a that are slidably engaged with the projections 18a are provided on both sides of the machine base 14, so that the upper surface of the projection 18a and the upper surface of the groove 14a are in contact with each other at least in the mold clamping position. A mold fixing structure for an injection molding device, characterized in that the mold fixing structure is formed so as to be in contact with each other.