JPH02229658A - Injection device for die casting machine - Google Patents

Abstract

PURPOSE:To manufacture an injection product having high quality by arranging plural penetrating holes at right angle to axial direction of an injection plunger, setting a hydraulic cylinder having a piston rod, which penetrates this hole and fits into a lock hole of a block, and arranging a magnetic scale and a detector at head side of the hydraulic cylinder. CONSTITUTION:An injection sleeve 4 is connected with lower part of a die 2 with a plunger tip 5 at bottom part of the injection sleeve 4 and the injection plunger 7. Plural penetrating holes 21 are arranged at right angle to the axial direction of the injection plunger 7. The hydraulic cylinder 21 arranged with the piston rod 20a penetrating the above hole 21 and fitting and reaching into the lock hole 22 in inner face of the block 6, is set in the block 6. The magnetic scale 30 and the detector 31a for detecting position of the injection plunger 7 are arranged at the head side of the hydraulic cylinder 20. By this method, insufficient running of molten metal in the die can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an injection device for a die-casting machine, and in particular,
The relative position of the plunger tip with respect to the injection sleeve is changed so that the amount of molten metal poured into the injection sleeve can be changed arbitrarily, and the injection sleeve is moved into the mold while maintaining this relative position. This relates to an injection device that is docked (inserted) in a predetermined position. [Prior art] In die-casting machines, whether or not the molten metal can be cast into the mold cavity while minimizing the temperature drop in the high-temperature state has a significant impact on the quality of the molded product. ．． This is because as the temperature of the molten metal decreases, the viscosity of the molten metal increases, causing poor flow of the molten metal within the mold cavity. Therefore, it is necessary to inject the molten metal into the mold cavity in the shortest possible time, so die casting machines are required to have a high injection speed. However, as the injection speed increases, the surface of the molten metal in the injection sleeve or mold cavity becomes disturbed and scatters, which entrains the atmosphere and creates bubbles during the molding process. Therefore, voids other than the substance in the molten metal, that is, cavities, often occur in the molded product, which often causes problems in terms of the strength, pressure resistance, and liquid resistance (non-leakage) of the molded product. ．． As is clear from the above explanation, in order to obtain a good die-cast molded product, it is necessary to cast at a low speed without disturbing the molten metal surface, and by shortening the time it takes for the molten metal in the injection sleeve to move into the mold cavity. That would be a good thing. [Problem to be solved by the invention] In order to shorten the travel time of the molten metal, it is sufficient to minimize the travel distance of the molten metal from the injection sleeve to the mold cavity, but depending on the shape of the molded product, the body structure may Since the corresponding amount of molten metal differs, an injection device in which the relative positions of the injection sleeve and plunger tip are set in a single manner and are linked cannot handle the variable amount of molten metal, and when the amount of molten metal is small, the injection sleeve This creates a large drop between the top surface of the molten metal stored inside the injection sleeve and the top end of the injection sleeve, resulting in unnecessary travel distance. Also, because the drop is large, surrounding air is likely to be drawn in when falling. [Means for Solving the Problems] Therefore, in the injection device of the present invention, after the tilted injection sleeve is supplied with hot water, the tilted and tilted back is raised to form a block supporting the injection sleeve and a bottom surface of the injection sleeve. In a die casting machine having an injection device that docks the injection sleeve to the lower part of the mold by interlocking the plunger tip and the injection plunger, through holes are provided at multiple locations in the axial direction of the injection plunger at right angles to the axial direction, and the through holes are arranged at right angles to the axial direction. A hydraulic cylinder having a piston rod that passes through the block and fits into and reaches a lock six bored on the inner surface of the block is disposed in the block, and a magnetic scale and a detector for detecting the position of the injection plunger are installed on the head side of the hydraulic cylinder. The configuration is as follows. [Function] Since the present invention is configured as described above, it becomes necessary to stop the casting of the molded product that has been operated up to that point and to cast a different type of molded product, and accordingly, the amount of molten metal in one shot decreases. If the amount of molten metal changes from the previous amount, it is necessary to change the relative position of the plunger tip to the injection sleeve. In other words, when molten metal is supplied to the injection sleeve,
Select a through-hole for the plunger from among multiple holes so that the top surface of the molten metal is close to the top of the injection sleeve to the extent that the amount of molten metal for one batch does not overflow the injection sleeve, and install it on the hydraulic cylinder head side or use a magnetic scale and detector. , operate the injection cylinder and move the plunger so that the axis of the selected through hole matches the axis of the piston rod of the hydraulic cylinder installed in the block. Then, move the piston rod of the hydraulic cylinder forward, pass it through this through hole, and set the tip of the piston rod in the lock hole drilled on the inner surface of the other end of the block. In this way, the block and plunger are temporarily engaged and integrated. After that, the hydraulic pressure at the inlet and outlet of the injection cylinder is turned off●load, and when the block is raised, the plunger tip rises in conjunction with the block, and the injection sleeve is docked at a predetermined position in the mold. After that, the above-mentioned lock is released (the piston rod of the hydraulic cylinder is retracted to the retraction limit), and the injection cylinder is moved forward to inject and fill the mold cavity with molten metal. [Embodiments] Hereinafter, embodiments of the present invention will be described in detail in relation to conventional examples based on the drawings. FIG. 1 is a longitudinal sectional view of an injection device showing an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view of FIG. 1. 3 and 4 are longitudinal sectional views showing the conventional embodiment, with FIG. 3 showing the sleeve when it is tilted, and FIG. 4 when the sleeve is tilted and raised. In the figure, 1 is a movable mold, 2 is a fixed mold, 3 is a cavity of the mold, 4 is an injection sleeve, 5 is a plunger tip slidably provided in the injection sleeve 4, and 6 is integrated with the injection sleeve 4. 7 is a plunger having a plunger tip 5 attached to its tip; 8 is an injection cylinder; 9 is a shaft for tilting the injection cylinder 8;
1 is a molten metal, 11 is a ladle, and 12 is a convex portion such as a collar provided at the connection between the piston rod 13 of the injection cylinder 8 and the plunger 7. Plunger tip 7 and plunger 7 form an injection plunger. Block 6 is formed into a hollow conical shape. A flange-like engaging portion l4 is formed inside the lower end of this block 6, and the upper surface of this engaging portion 14 is provided with a coupling that connects the piston rod 13 and the plunger 7, and a collar at the bottom thereof. Convex portion 12 formed using etc.
It engages with the outer periphery of the lower surface. When the block 6 rises, the engagement part l4 holds the protrusion l2, and the protrusion 12 also rises together, so that the plunger tip 5 and the injection sleeve 4 can always rise at the same time. ing. A cylinder 15 is formed in the vertical direction within the block 6, and the tip of a ram 16 fixed to the rod end side of the injection cylinder 8 is slidably fitted into the cylinder 15, not shown. The block 6 can be raised by supplying hydraulic oil from a hydraulic source to the cylinder 15 through the ram 16 via the bow C. In addition to the above configuration, the present invention has other features. As shown in FIG. 2, through holes 21 are provided at multiple locations in the axial direction of the injection plunger 7 at approximately equal intervals in a direction perpendicular to the axis, as shown in FIG. A hydraulic cylinder for a positioning lock was fixed with a bolt, and a lock hole 22 into which the tip of a piston rod 20a fit was provided at the other end of the block. It is desirable that the tips of the through hole 21, lock hole 22, and piston rod 20a are all chamfered. Further, as shown in FIG. 1, a magnetic scale 30 is attached to the head side of the injection cylinder 8 via a support.
A column 31 that slides through the injection cylinder is fixed to the piston 8a of the injection cylinder 8, and a detector 31a is disposed at the tip of the column 31, facing the magnetic scale 30. Next, the operation of the device will be explained. FIG. 3 shows a state in which the entire injection device is tilted by a tilting device (not shown), and molten metal 10 is poured into the injection sleeve 4 from the ladle 11. After pouring is completed,
Next, the entire injection device is tilted back up, that is, the entire injection device is rotated around axis 9 to return to its original upright position. This is the situation shown in Figure 4. Thereafter, by introducing hydraulic pressure into the cylinder 15 through the boat C, the block 6 is raised, and the injection sleeve 4 is fitted into the fixed mold 2. At this time, the plunger 7 is pulled up by the convex portion l2 due to the rise of the block 6, so
There is no change in the relative position of the injection sleeve 4 and the plunger tip 5, they rise together, and there is no shaking of the molten metal. Next, hydraulic pressure is introduced into the bow }a, pressure is built up on the head side of the injection cylinder 8, and the injection plunger 7 and plunger tip 5 start to rise. Fill cavity 3 to be formed. The above are the basic operating conditions of the conventional device and the device of the present invention, but the liquid level in the injection sleeve after pouring as shown in FIG. 4 is much lower than the upper end of the injection sleeve. Therefore, as mentioned above, the distance traveled when filling the cavity with molten metal is large, which means that each injection operation involves a wasted forward and backward movement, and cooling is also rapid. Also, when pouring hot water. Since the falling distance is long, it has the disadvantage that surrounding gas is easily drawn into the molten metal. In the present invention, if for some reason it is necessary to change the mold and manufacture a different type of small molded product, and the amount of hot water supplied at one time decreases, the hot water supply to the injection sleeve is performed as shown in Fig. 1. The optimum through hole is selected so that the plunger tip can be positioned near the top of the injection sleeve (the LO position shown in the figure) so that the surface of the subsequent molten metal does not overflow from the injection sleeve, and the magnetic scale 30 and The injection plunger 7 is moved by the detector 31a to a position where the axis of the piston rod 20a of the hydraulic cylinder 20 disposed in the block 6 coincides with the selected through hole, and after stopping, the piston rod 20a is advanced. , through this through hole, and the tip of the piston rod 20a is fitted into the lock hole 22 bored at the other end. After that, after performing the operations of tilting, pouring, and tilting back, the hydraulic pressure of the injection cylinder is turned off ● load, and the block is raised as described above. At this time, the convex portion l2 and the engaging portion l4 of the injection plunger 7 are not in contact with each other, and the injection plunger 7 is caused by the engagement between the through hole 2l and the piston rod 20a.
The injection sleeve 4 and plunger tip 5 move up in conjunction with each other. After the mold is docked, release the lock to the through hole (retract the piston rod 20a of the hydraulic cylinder 20)
Then, the plunger tip 7 is advanced by the injection cylinder 8 to fill the mold cavity with molten metal. Furthermore, if temperature conditions permit, the magnetic scale and detector can be installed inside the block. Furthermore, when the injection sleeve and the plunger tip are moved up in conjunction with each other using the convex portion 12 and the engaging portion 14, it is necessary to provide an electrical interlock to hold the piston rod of the hydraulic cylinder 20 at the retraction limit. There is. In addition, the convex portion l2 and the engaging portion 1
4 is used during operations that require the largest amount of hot water to be supplied to the molded parts of the die-casting machine.In this case as well, after the supply of hot water to the injection sleeve is completed, the convex portion is used so that the surface of the molten metal is near the top of the injection sleeve. It is desirable to set 12 to plunger 7. Furthermore, the convex portion l2 and the engaging portion l4 may be eliminated. As explained above, in the present invention, even if the molded product of the die-casting machine is changed and the amount of hot water supplied changes, the relative position of the plunger tip with respect to the injection sleeve is adjusted accordingly by the operation of the hydraulic cylinder. The injection plunger can be locked by passing the piston rod through the hole, so the injection sleeve and plunger tip can be linked together to dock into the mold. By combining the magnetic scale and detector, the plunger position can be automatically adjusted to any through hole position. [Effects of the Invention] In the present invention, the position of the plunger tip can be automatically set appropriately according to the amount of hot water supplied, and the surface of the molten metal in the injection plunger can always be maintained near the upper end of the injection sleeve, thereby reducing unnecessary travel distance. Therefore, there is less cooling and solidification of the molten metal, ensuring optimal injection conditions. Therefore, it is possible to prevent the temperature of the molten metal from decreasing, increasing the viscosity of the molten metal, and improperly circulating the molten metal in the mold as much as possible, and there is also little air entrainment during pouring, resulting in high strength, pressure resistance, and liquid resistance. You can easily obtain high-quality injection molded products.

[Brief explanation of the drawing]

1 and 2 show an embodiment according to the present invention, with FIG. 1 being an overall vertical sectional view of the injection device, and FIG. 2 being a partially enlarged sectional view. Figures 3 and 4 are longitudinal sectional views showing conventional embodiments. 1... Fixed mold, 2... Movable mold, 3... Cavity 4. 4...
- Injection sleeve, 5... Plunger chip, 6... Block, 7... Injection plunger, 8... Injection cylinder, 12...
...Convex part, 4...Engagement part, 15...
...Cylinder, 6...Ram, 2
0...Hydraulic cylinder, Oa...Piston rod, 1...Through hole, 22...Lock hole, 0...Magnetic scale, 31... ...column, la...detector. Patent applicant: Ube Industries, Ltd.

Claims (1)

[Scope of Claims] After supplying hot water to the tilted injection sleeve, the tilted back is caused to interlock the block supporting the injection sleeve, the plunger tip and the injection plunger forming the bottom surface of the injection sleeve, and the injection sleeve is In a die casting machine having an injection device that docks the injection plunger to the lower part of the mold, through holes are provided at multiple locations in the axial direction of the injection plunger perpendicular to the axial direction, and a lock is inserted through the through holes and drilled on the inner surface of the block. An injection die casting machine characterized in that a hydraulic cylinder having a piston rod that fits into and reaches the hole is disposed in the block, and a magnetic scale and a detector for detecting the position of the injection plunger are provided on the head side of the hydraulic cylinder. Device.