JPS63140747A - Vertical injection device - Google Patents

Abstract

PURPOSE:To prevent the generation of a blowhole on a forged product by making the passage of a melting body between an injection sleeve insertion hole and the cavity of a die in a smaller diameter at the cavity side and providing a pin having slightly smaller diameter than this small diameter part freely insertably. CONSTITUTION:The runner where a molten metal passes with the advance of a plunger chip 48 is provided between the inner holes 33a, 47a of injection sleeves 33, 37 and a die cavity 8, and the part close to the die cavity is formed in a smaller diameter. The pin 63 slightly smaller diameter than a freely inserting small diameter part by the work of a cylinder 61 is provided at this small diameter part. The plunger chip 48 is advanced with this composition and the molten metal is filled up by injecting it inside the cavity 8 via the runner. The pin 63 is descended by advancing the piston rod 62 of the cylinder 61 with an oil pressure and when the molten metal inside a gate 49a is plunged, the molten metal is spread over up to the corners of the cavity 8 by the feeding effect of the pin 63. The generation of blow holes on a forged product is thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vertical injection device that injects a molten material into a mold cavity from directly below.

[Conventional technology]

For example, vertical die-casting machines are often used to cast aluminum-covered automobile disc foils because there is little gas entrainment during injection of molten metal. FIG. 6 is a schematic longitudinal cross-sectional view of the mold and injection device of this type of conventional die-casting machine, and this will be explained based on the same figure. A lower mold 2 having a cylindrical convex portion is attached to the movable platen 3, which is supported by a mold clamping cylinder (not shown) and moves up and down, and an upper mold 4 having a low convex portion at the center. is installed. A plurality of cores 5 are inserted into the molds 2 and 4 so as to be movable horizontally from a position dividing the circumferential direction into two equal parts, and a piston of a cylinder 6 supported on the movable platen 3 side. It is configured to move forward and backward in the υ horizontal direction by moving the rod 7 forward and backward. Then, the cavity 8 is formed by both molds 2.4 and the closed core 5.
is formed. An injection sleeve 9 is inserted into the sleeve hole formed in the fixed platen 1 and the lower mold 2 from below so that it can be inserted and removed from below, and a plunger tip 10 that moves forward and backward by an injection cylinder (not shown) is inserted into the injection sleeve 9. are fitted so that they can move forward and backward. 11 is the molten metal injected with the injection sleeve 9 pulled out from the sleeve hole.

With the structure described above, when the molten metal 11 is injected into the injection sleeve and inserted into the sleeve hole, and then the plunger tip 10t is advanced, the molten metal 11 is injected into the cavity 8. After the molten metal 11 has solidified and cooled, the movable platen 3 is raised to open the mold, and the core 5 is opened laterally, and the solidified product in the cavity is extruded by a product extrusion device (not shown) and then machined. Take it outside.

In order to explain the flow of the molten metal 11 in the cavity in such an injection operation, a disk portion 8at of the cavity 8, which corresponds to the disk of the disk foil in FIG.
-When expressed schematically, the rim portion 8bt of the cavity 8 is disk-shaped as shown in FIG. 7 and corresponds to the rim.
When expressed schematically, it has a cylindrical shape as shown in FIG.

The molten metal 11 pushed up by the plunger tip 10 flows radially through the disk portion 8a as shown by the arrows in FIG. 7, and then hangs down the rim portion 8b by its own weight as shown by the arrows in FIG. FIG. 9 is a perspective view showing the state of the molten metal flowing in this manner, and as the molten metal 11 flowing in the above manner hangs down on the rim portion 8b, the temperature unevenness of the mold 24 is reduced. Uneven adhesion of the mold release agent, scratches on the surfaces of the molds 2 and 4, etc. may cause irregularities in the flowability of the metal, and gas may be trapped in the molten metal 11 as shown by reference numeral 12 in FIG. Once this is completed, the molten metal 11 will entrain gas and create cavities in the molded product.

In this way, if injection is performed in the cavity 8 with the disk portion 8a positioned above, gas may be drawn in as described above.To avoid this, the cavity 8 is placed so that the disk portion 8a It would be better to make the rim part 8b stand up from the bottom side, but in this case, the hub decorative surface of the product becomes the injection sleeve 9 side, and unnecessary molten metal solidified material called biscuit is attached to this surface. Since cutting this after molding would impair the aesthetic appearance of the decorative surface, conventionally molding has been unavoidably carried out with the disk portion 8a facing upward.

[Problem that the invention seeks to solve]

In this way, in the past, molding was performed with the disk portion 8a facing upward, so in order to avoid the entrainment of the gas, injection had to be performed at a relatively low speed.
The above reason is that the flow form of the bath water 11 in the cavity 8 must be controlled by the speed of the plunger tip 10 in order to stabilize the quality of the product, rather than being a fool's errand that reduces productivity. There were problems in that the output could not be said to be controllable and the stability of quality could not be measured. However, if the injection speed is controlled by the speed of the plunger tip 10, the injection speed becomes faster and the entrainment of the gas increases.

[Means for solving problems]

In order to solve these problems, in the present invention, at least the part of the melt passage between the injection sleeve insertion hole of the lower mold and the mold cavity is made smaller than the inner diameter of the injection sleeve. The pin is also formed to have a small diameter, and the pin is inserted into and removed from the small diameter part of the melt passage, and the diameter of the fitted part is slightly smaller than the diameter of the small diameter part, so that it can be moved up and down to the upper mold side. was supported.

[Effect]

When the plunger tip is raised by the injection cylinder, the melt in the injection sleeve is injected into the mold cavity through the melt passage. Immediately before or after the end of injection, when the pin is lowered and protruded downward from the upper mold while applying upward force to the plunger tip, the protruding tip of this pin is installed in the small diameter part of the melt passage. When the molten material solidifies in this state, the solidified material in the small diameter portion becomes a thin cylindrical shape that is formed in the swivel of the pin. Then, when the product is solidified and then opened, the product rises with respect to the upper mold, and the attached solidified product is cut from the thin-walled cylindrical portion, leaving the biscuit in the injection sleeve. When the pin is lowered, the pin removes the molten material in the small diameter portion, thereby acting as a riser.

〔Example〕

This embodiment shows an example in which the present invention is implemented in a mold opening/closing unit of a rotary die-casting machine. Fig. 1 is a longitudinal cross-sectional view of the mold opening/closing unit in which the present invention is implemented, and Fig. 2 is a partial view of the same with the top plate removed. FIG. 3 is an enlarged longitudinal cross-sectional view of the main part, and FIG. 4 is an explanatory diagram of the operation of the runner extrusion device. In these figures, the rotary die-casting machine is equipped with a rotary table and three sets of mold opening/closing units mounted at positions that divide the outer periphery of the rotary table into three equal parts in the circumferential direction. Three work stations are arranged on the orbit of the surrounding mold opening/closing unit at positions dividing the circumferential direction into three equal parts. Each opening/closing unit is equipped with a mold, and each of the three stations performs mold clamping and injection, weight and product removal, mold cleaning, and mold release agent spraying. The table stops every 120° rotation to perform these operations, and one rotation completes one cycle. The figure shows the mold opening/closing unit stopped at the mold clamping and injection station.
A mold clamping device and an injection device (not shown) are provided above and below in FIG.

In the figure, the mold opening/closing unit 20 includes a mounting plate 21 detachably fixed on a rotating table (not shown), and a pair of mold opening/closing cylinders 22 erected on both left and right sides of the mounting plate 21. Piston rod 23 that moves up and down with hydraulic pressure
A horizontal plate-like top plate 24 is fixedly supported at the working end of the holder.

As the piston rod 23 advances and retreats, the top plate 24 and an upper mold, etc., which will be described later, are guided by four guide rods (not shown) and are moved up and down to perform spreading and alignment. ing. The entire mounting plate 21 is designated by the symbol 2.
A sleeve support plate 26 of the lower mold plate 5 is fixed, and the lower mold 25 has an annular core retaining ring 2 fixed to this sleeve support plate 26 and a plurality of bolts 27.
8, an annular metal holder 30 supported by a plurality of guide pins 29 implanted in the sleeve support plate 26 so as to be movable up and down with a small stroke, and a ring-shaped metal holder 30 that is fitted onto the inner circumferential surface of the mold holder 30. It is formed by a mold body 32 which is fitted together and fixed with bolts 31. 33 is a fixed sleeve formed in a stepped cylindrical shape, and is connected to the three members 26, 30, and 32 of the lower mold.
The ring 34 is inserted into the sleeve hole formed in the sleeve support plate 26, and is prevented from coming off from the sleeve hole by a ring 34 screwed to the sleeve support plate 26.

On the other hand, on the bottom surface of the top frame 24, there is a symbol 35 as a whole.
The substrate 36 of the upper mold shown in is fixed, and the upper mold 35
This substrate 36, a support plate 38 which is approximately octagonal in plan view and which is integrally fixed thereto with a plurality of bolts 3T, and a mold holder which is fitted and fixed in a recessed hole 38a of this support plate 38. 3
9, and a mold body 41 fitted into the recessed hole 39a of the mold holder 39 and fixed with bolts 40.

In the lower end flange portion of the support plate 38, which is formed into an octagonal shape, grooves 38b are formed at the center of every other four sides, and the end faces of each side provided with the grooves 38b are provided with grooves 38b. , the cylinder support plate 42 engages the bulge in the recess #38b and the bolt 4
It is fixed at 3. A core cylinder 44 has a flange fixed to four bulges, is connected to a pressure oil source, and is equipped with a limit switch 44a for stroke regulation. At the end,
Cores 46 are each fixed. The movement of each core 46 is restricted by the core retaining ring 28 in the state shown in FIG. , piste/
The rods 45 are configured to open simultaneously in the radial direction by retreating the rods 45. Further, when the four cores are closed as shown in FIG. 1, a perfect circle is formed by the four inner peripheral surfaces.

Then, the upper and lower mold bodies 41.32 are matched,
Together with the four closed cores 46, a cavity 8 shown with the same reference numerals as in FIG. 6 is formed. As is clear from a comparison between FIG. 1 and FIG. 6, in this device, the cavity 8 is inverted upside down compared to the conventional one, and the disk portion 8a is positioned at the lower level of the entire height of the cavity 8. are doing. A cylindrical injection sleeve 47 supported on the upper end surface of an injection cylinder (not shown) via a block is inserted into and removed from the inner hole of the fixed sleeve 33, and is inserted into the inner hole by the hydraulic pressure of the injection cylinder. A plunger tip 48a serving as the head of the plunger 48 that moves forward and backward is fitted.

Inner holes 33a of both sleeves 33.47 have the same diameter
, 47a and the cavity 8 is provided with a runner 49 as a passage for the molten metal injected into the inner hole 33a and injected into the cavity 8 by the advancement of the plunger tip 48&. This runner 49 is formed by a gate 49a as a cylindrical hole with a smaller diameter than the inner holes 33a and 47a formed at the side of the cavity 8, and a tapered hole 49b formed at the inner hole 33a@D. 49
The lower end surface of the disk portion 8m following point a becomes the decorative surface of the product solidified within the cavity 8.

Outside the upper end of the annular rim portion 8b of the cavity 8, a runner 50 formed in an annular shape concentric with the rim portion 8b is provided on the lower end surface of the mold holder 39. are communicated through a plurality of radially formed gates 51. What is generally designated by the reference numeral 52 is a gas venting device for removing the gas in the cavity 8 to the outside of the machine during injection, and as shown in FIG. This degassing device 52 is disposed between the lower mold 25 and the lower mold 25, and is divided into a valve seat portion 53 and a cylinder portion 54. The valve seat part 53 is divided into a front side and a paper back side in FIG. 1, and each core 4 on both sides
6, and the cylinder portion 54 is movable in the axial direction via links 57 and 58 to the piston rod 56 of the degassing cylinder 55 which is pivotally connected to the support plate 38. is formed. This gas venting device 52 is a conventionally known cylinder type gas venting device,
The gas passage 59 communicates with the runner 50, and the valve 60 opens and closes the valve seat at the end of the gas passage 59.
is opened and the gas is discharged by the pressure of the molten metal or a vacuum device, and the valve 60 is closed by the inertia of the molten metal or an electric signal to block the discharge of the molten metal to the outside of the valve seat. Further, the cylinder portion 54 functions to ensure that the valve is closed and to hold the valve 60 in each open and closed position, and when the upper mold 35 is opened, the valve seat portion 54
3 to allow its opening and closing, and rise together with the upper mold 35.

Next, we will explain mold clamping and opening. Mold clamping is performed by lowering the top plate 24 from the mold matching state shown in FIG. 1 by a mold clamping cylinder (not shown) against the hydraulic pressure of the opening/closing cylinder 22, and the mold opening is performed after the mold clamping cylinder is withdrawn. This is done by moving the piston rod 23 of the mold opening/closing cylinder 22 forward from the illustrated state, and the top plate 24, upper mold 35, gas venting device 52, etc. rise together. Then, the product solidified in the cavity 8 at ℃ reaches the υ upper mold 351111 and rises.

Next, the gate 49 & cutting device and runner 5 when opening the mold.
0 cutting device and product extrusion device will be explained.

A pin extrusion cylinder 61 is fixed to the center of the top plate 24), and its piston rod 62 passes through a round hole in the top plate 24 and projects downward. Reference numeral 63 denotes a round bar-shaped pin which extends downward by having a threaded hole screwed into the protruding threaded portion of the piston rod 62, and is divided into three upper and lower stages and then joined, and the diameter of the lower stage is equal to the diameter of the above-mentioned game. It is formed to have a slightly smaller diameter than the diameter of 49a. This pin 63 is supported by a bearing 64 which is clamped and fixed to the base plate 36 and the support plate 3B. Support plate 38. A bearing 65, which is clamped and fixed to the support plate 38 and the mold body 41, and the mold body 41. and a cartridge 66 fixed to the mold body 41.
The υ pin 63 is configured to move up and down between the solid line position and the chain line position in FIG. 3 by moving the piston rod 62 forward and backward with the hydraulic pressure of the pin extrusion cylinder 61.

That is, before the molten metal 6T in the cavity 8 solidifies, the pin 6
3 descends to the chain line position, the pin 63 removes the molten metal 6T and acts as a feeder, and the hole is inserted through the hole leaving a thin solidified molten metal 6B in the gate 49a. There is. Then, as will be described later, the product and the biscuit 69 are separated by cutting the solidified molten material 68 when the mold is opened. Note that the pin 63 is provided with a cooling device having holes 71 for cooling water, etc., and is configured in four ways so as to cool the pin 63 heated with molten metal.

Further, a plurality of product extrusion cylinders 72 are fixed to the upper surface of the top plate 24, and an ejector plate 74 parallel to the top plate 24 is fixedly supported at the upper end of the piston rod 73. The plurality of pins 75 fixed to the plate pass through the holes in the top plate 24 and the base plate 36 and protrude downward, and then the screws of the extrusion plate T6 provided in the space of the support plate 38 so as to be movable up and down. It is screwed into the hole. Each of the plurality of extrusion pins 77 and 78 hanging down with their heads held by the extrusion plate T6 divided into two upper and lower parts is a hub extrusion plate provided vertically movably within the space of the mold holder 39. T9 and the upper end of the rim portion 8b are respectively brought into contact with the lower ends thereof, and when the product ejection cylinder T2 is operated after the mold is opened and the ejector plate 74 is lowered, the pin 75. Extrusion plate 76, extrusion pin 77.7B, hub extrusion plate T9, and hub extrusion plate 79
The push-out pin 80' (i
- configured to force the product downwardly out of the cavity 8 through. Note that the hub extrusion plate 79 is connected to the guide pin 8
1 and moves up and down, and is rebounded by a compression coil spring 82 to return to the raised position.

Furthermore, a plurality of cylindrical stoppers 83 are provided in round holes disposed at positions dividing the lower end outer circumferential portion of the mold holder 39 into a plurality of equal parts in the circumferential direction. The tapered ends of the rods 85, which are suspended by their own weight from the extrusion plate T6, are respectively engaged in the tapered holes 83& provided in each stopper 83. Then, when the push-out plate T6 descends by the stroke indicated by the symbol a in FIG.
are configured to move all at once in the direction of the arrow.

Further, the lower ends of each of the extrusion pins 86, which are supported and suspended at positions dividing the outer circumference of the extrusion plate 76 into a plurality of equal parts in the circumferential direction, are in contact with the runner 50, and the concave holes of the second runner 50 are A circular projection 83b provided on the stopper 83 is removably inserted and seals the solidified molten metal in the runner 50, and then the stopper 83 moves and the projection 83. The push-out pin 86 is configured so that when the push-out plate 76 further descends after the stroke b is removed and descends by a stroke indicated by the reference numeral 2a in FIG. 1, the push-out pin 86 begins to descend. When the extrusion plate 76 starts to descend while the protrusion 83b of the stopper 83 is inserted, the product is first extruded by the extrusion pins 78 and 80 and cut by the gate 51, and an annular solidified substance is formed inside the runner 50. remains held by the protrusion 83b. After this, the stopper 83 moves with the above-mentioned cyst lobe a, and the solidified material in the runner 50 is pushed out with the stroke 2a.

1 is a cylinder fixed to the upper surface of the top plate 24 for regulating extrusion timing, and between the piston rod 88 at the upper limit and the ejector plate 74, the rod 85 stroke a
The same gap a is provided for the ejector grate 7.
When the piston rod 4 descends and comes into contact with the piston rod 88, the lowering of the piston rod 88 is temporarily stopped by control of an electromagnetic valve and the like, and then the piston rod 88 descends again. That is, this stopping position is the position where the rod 85 starts to descend and the product is pushed out by a distance a, and by doing this, the lower runner 50 of the υ product is rotated and pushed out. This eliminates the need for difficult runner removal work and avoids damage to the product during removal. In addition, the reference numeral 89 is shown in FIG.
The one shown with is a cylinder 90 fixed to the mounting plate 21 side.
It is a push-up cylinder consisting of a piston 91 fixed to the lower platen side, and in the event of a mistake in the joint, the push-up cylinder 49a
It is configured to operate when the mold holder 30 and the mold body 32 are not cut to avoid an accident.

The operation of the vertical injection device configured as above will be explained based on the explanation of the operation in each of the above figures and FIG. 5. The mold opening/closing unit 21, which has been sprayed with a mold release agent and matched at the upstream work station, is rotated by the rotation of the rotary table to the mold clamping and injection station and stopped, so that the top plate 24 is closed by the mold clamping cylinder. P mold clamping is performed by pressing downward. Simultaneously with mold clamping, the injection sleeve 4T into which the molten metal 69 has been injected is inserted into the inner hole of the fixed sleeve 33 and joined, and when the plunger tip 48 is advanced, the molten metal 69 is injected into the cavity 8 and filled. FIG. 5 (&) shows the injection completed.

When the piston rod 62 of the pin extrusion cylinder 61 is hydraulically advanced just before or after the end of this injection, that is, before the molten metal 69 begins to solidify, the pin 63 descends and protrudes from the cartridge 66, as shown in FIG. As shown in b), the molten metal 69 in the gate 49a is pushed into the molten metal 69, and at this time, the molten metal 69 in the gate 49a is removed by the pin 63 and flows into the cavity 8, acting as a riser.
is distributed to every corner of cavity 8. In this state, molten metal 6
9 begins to solidify, and after a predetermined period of time, the assimilation is completed and the product becomes a product.Then, when the rotary table rotates 120' and the mold opening/closing unit 21 stops at the product removal station, the piston rod 23 is moved by the hydraulic pressure of the mold opening/closing cylinder 22. moves forward and the top plate 24 rises, so the entire upper mold 35 integrated therewith rises and the mold is opened as shown in FIG. 5(c).In this case, as described above, the gate 49a
Since the diameter difference between the pin 63 and the pin 49a is small, a thin cylindrical solidified molten metal is formed in the rotation of the pin 63. The product 100 in the capacity that arrives and rises is biscuit 1.
01 remains in the fixed sleeve 33 and the tapered hole 49b, and is easily cut from the thin cylindrical portion and rises together with the upper mold 35. After the mold is opened in this manner, when the piston rod T3 is retreated by the hydraulic pressure of the product extrusion cylinder 72, the top plate 24 begins to descend. As a result, the push-out pins 77 and 78, which are integral with the push-out plate γ6, descend first, and the product 100 with which their tips come into contact begins to be pushed out from the cavity 8. At this time, as shown in FIG. 4(a), the protrusion 83b of the stopper 83 is engaged with the concave hole of the runner 50, so even if the product 100 is pushed out and lowered, the launch 50 remains as it is and the product 100 The runner 50 is separated from the gate 51. FIG. 5(d) shows a state where only the product has been extruded and the lunch 50 remains. When the top plate 24 descends by stroke a, the cylinder 8
Since the piston rod 88 comes into contact with the upper end of the piston rod 88 of No. 7, the downward movement is temporarily stopped, and after a predetermined timing, the downward movement starts again.

When restarting this downward movement, the push-out plate 76
Since the and rod 85 are integrated, the rod 85 also descends. As the rod 85 descends, its lower end pushes the tapered hole 83at of the stopper 83, and the taper action moves the υ stopper 83 in the direction of the arrow, so that the protrusion 83b comes out of the concave hole of the runner 50. When the top plate 24 continues to descend and further descends by a stroke a, descending by a total of 21 steps, the push-out plate 76 and the push-out pin 80 become integrated, so the push-out pin 86 also begins to move down to form an annular shape with the lower end of the seventh abutting the top plate 24. runner 50 is extruded. FIG. 5(e) shows this state. Then, as shown in FIG. 5(f),
When the extrusion device 102 is moved between the two opened molds and the piston rod 103 is advanced, the biscuit 104 is extruded.

In the case of a disc foil, the product 100 taken out from the mold with such markings has a decorative surface on the lower side of the hub in the figure, but this is because only a thin cylindrical solidified material is attached thereto. , it is easy to remove, and the aesthetic appearance is not impaired even after removal.

Although this embodiment shows an example in which the present invention is applied to a rotary die-casting machine, it goes without saying that the present invention can be similarly applied to a stationary die-casting machine. It can also be applied to injection molding machines for plastics.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, in the vertical injection device, at least the mold cavity approach of the melt passage between the injection tube IJ-tub insertion hole of the lower mold and the mold cavity is provided. 9, the diameter of the inner hole of the injection sleeve is also smaller than that of the injection sleeve, and the diameter of the fitting part that is fitted into the small diameter part of the melt passage so as to be freely inserted and removed is slightly smaller than the diameter of the small diameter part. By supporting the pin on the upper mold side so that it can move up and down, even if a part with a diameter smaller than the diameter of the injection sleeve is provided in the molten material passage, only a thin solidified material will be there due to the action of the pin. The product and biscuit can be easily separated when the mold is opened, and as a result, it is possible to mold a disc foil with a low hub without compromising the aesthetic appearance of the cosmetic surface. Product quality is greatly improved as there is no entrainment, and there is no need to reduce the injection speed to avoid gas entrainment, improving productivity. Furthermore, the pin removes the molten metal in the small diameter portion, which acts as a feeder action and spreads the molten metal to every corner of the cavity, improving the quality of the product.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the vertical injection device according to the present invention, FIG. 1 is a vertical cross-sectional view of a rotary die-casting machine dose opening/closing unit in which this is implemented, and FIG. 2 is the same with the top plate removed. FIG. 3 is an enlarged vertical cross-sectional view of the main part, FIGS. 4(a) and (b) are explanatory diagrams of the operation of the runner extrusion device, and FIGS. 5(a) to (f) is an explanatory diagram of injection, product, runner, and extrusion operation of biscuits; Figures 6 to 9 show a conventional vertical injection device; Figure 6 is a schematic vertical cross-sectional view of the mold and injection device; Figure 7 8 is a schematic diagram of the disk portion, FIG. 8 is a schematic diagram of the rim portion, and FIG. 9 is an explanatory diagram showing the flow state of the molten metal. 8...Cavity, 25...Lower mold, 4γ...
O, injection sleeve, 49.9, runner, 49a, fist,
Gate, 61... Pin extrusion cylinder, 62...
-Piston rod, 63...pin.

Claims (1)

[Claims] At least the part of the melt passage between the injection sleeve insertion hole of the lower mold and the mold cavity is formed to have a smaller diameter than the inner hole diameter of the injection sleeve, and 1. A vertical injection device characterized in that a pin that is fitted in a manner that can be freely inserted and removed and whose fitting portion has a slightly smaller diameter than the diameter of the small diameter portion is supported on an upper mold side so as to be able to move up and down.