US2094080A - Die casting machine - Google Patents

Description

DIE CASTING MACHINE Filed Oct. 6. 1934 3 I I I 2.94 fl FR 2; 2a 57 w H625: INV T0.

56.6. mafliw 772% ATTORNEYS.

Patented Sept. 28, 1937 PATENT OFFICE DIE CASTING MACHINE William A. Parker, Erie, Pa.

Application October 6, 1934, Serial No. 747,244

2 Claims.

The present invention is designed to improve die casting machines and has particular reference to the manner of charging and discharging the mold and involves preferably providingone of the mold parts with engaging surfaces so that the casting may be uniformly retained in one of the mold parts as the mold is opened so that the mold discharge means may be readily applied to the casting after the mold is suitably opened. The invention also involves the provision of a charging system in which one end of the charging passage is chilled and the opposite end heated so that the separation of the .molten metal from the chilled metal of the casting may be localized.

In this way the chilled plug of the metal in the passage may be withdrawn with the casting as the mold is opened and the molten metal may be returned to the supply. The invention also involves an automatically actuated die casting machine which is continuous in its operation and automatic in charging and discharging the mold. Features and details of the invention will appear more fully from the specification and claims.

A preferred embodiment of the invention is illustrated in the accompanying drawing as follows:-

Fig. 1 shows a side elevation of the machine, partly in section.

Fig. 2 a section on the line 2-2 in Fig. 1. Fig. 3 an enlarged view of the mold charging tube.

Fig. 4 a schematic view of the'driving mechanism.

Fig. 5 a section of the mold with the parts in closed position.

Fig. 6 a section on the line 6-6 in Fig. 5.

I marks the machine frame and 2 legs supporting the frame.

er 4, the burner being adapted to heat the molten metal receptacle 5. A charging cylinder 6 is supported by the receptacle and communicates with the receptacle through a port I. A plunger 8 operates in the cylinder, closing the port 'I in its downward stroke so as to force the-molten metal to the mold. A piston rod 9 extends from.

A heating chamber 3 is provided with a burn (01.22 10) discharge opening I'Ia. A connection I8 also extends to the valve I5 and leads to the lower end of the cylinder I I. This passage is also alternately connected by the ports I! with the inlet passage I6 and the discharge passage Ila so that 5 as the valve is operated in proper timing with relation to the other operations of the machine by the mechanism hereinafter described the piston Ill is forced downwardly carrying with it the plunger 8 and expelling a charge for the mold. 10 At the proper interval the piston 8 is returned with an initial suction action in its return movement to 'facilitate the separation of the molten metal from he chilled metal of the mold and to uncover the port so as to permit an inflow of 15 molten metal. In the initial movement of the piston, the piston is retarded by the extension I2 which restricts the incoming air so that the filling of the air above the piston I0 is comparatively slow. This is desirable in that the plunger ,20 does not violently expel the molten metal from the port I and gives a gradual start to the flow in the passage. A communicating port I9 extends from the lower end of the cylinder 6 up to the charging tube 20. The charging tube is fixed 25 on the walls of the receptacle at the discharge end of the port I9. The charging tube has a restriction 2I formed by the taper 22 which has its smaller end at the restriction. This charging tube is arranged in an opening 23am the mold supporting plate 23. A mold member 24 as shown has a mold cavity 25 and has a seat 24w adapted to seat on a seat 20a at the end of the charging tube. This connection permits of the ready charging of the mold. The mold member is provided with chambers 26 adapted to receive cooling liquid through connections (not shown). The mold supporting plate 23 is mounted on brackets 21 extending from the burner chamber 3. The hot gases from the burner are discharged through an opening 30. and deflected into the opening 23a. As a result the charging tube is subjected at one end to the heat of the hot gases and at the opposite end to the chilling effect of 45 the cooling liquids in the chamber 26. There is,

- therefore; a chilling of the metal in the one end 25a of the mold member is also tapered so as to readily facilitate the removal of the charging plug of metal which may be attached to the casting.

By this structure a fixed relation is maintained through the charging passage to the mold, the mold end of this passage being tapered to permit the direct axial removal of the solidified plug of metal attached to the casting. The remaining portion of the passage returns through the passage to that part of the passage within the receptacle so as to acquire and maintain the desired temperature. This is accomplished without any intervening valves, without the breaking.

of the connection between castings, and affords a very definite uniformity of product. Lower guide rods 28 extend from the plate 23 to a cross member 30a. The cross member is fixed on a gear case 30 which case is mounted on the frame I. Guide rods 28 extend beyond the cross member 39a and into a rear pressure head 3| to which they are secured. An upper guide rod 29 is secured to and extends between the supporting plate 23 and the head 3|. A reciprocating head 32 has bearings 33 which are slidingly mounted on the rods 28 and 29. A toggle lever has members 34 and 35 pivotally connected by pins 36. The forward end of the lever is pivotally connected at 31 with the reciprocating head 32. The rear member 35 is pivotally connected with the head 3| by a pin 38. A link 39 is connected by a pin 49 with the lever 34 adjacent to the pivotal connection at 36. The link is connected by a crank pin 4| with a crank 42. The crank 42 is fixed on a drive shaft 43. As indicated in Fig. 2, the toggle lever mechanism and crank are duplicated at each side of the machine, there being a crank at each end of the shaft 43. A worm gear 45 is fixed on the shaft 43 and meshes with a worm 46. The worm is arranged on a worm shaft 41 and the shaft 41 is journaled in bearings 48 in the case 30. A driving pulley 49 is fixed on the worm shaft and is driven from a belt 50 from a pulley The pulley 5| is fixed on a rotor shaft 52 of a motor 53. Through this mechanism it will'readily be seen that the crank is rotated and through its rotation reciprocates the link 39 swinging the toggle lever so as to open and close the mold. This toggle lever mechanism is brought to a position to close the mold with the members 34 and 35 in substantial alinement. As indicated in Fig. 4, the crank is at the points a and b when the parts 34 and 35 are in exact alinement. They are brought from slightly below that point in the travel of the crank represented at c. In actual operation the mold is maintained in closed position from the point 11 to the point e, the spring of the included mechanism permitting the very slight variation in this interval. In other words, while there is a continuous motion of the crank and While the toggle lever in its straightened position positively holds the molds under pressure and in closed position a dwell in this closed position is accomplished by making the closed position in the part of the crank travel where the movement from the crank to the toggle levers and the movement of the toggle levers results in very little variation in the straight line arrangement of the toggle levers. Thus a simple, powerful driving connection is provided, comparatively fast during the. opening and closing movements and with a dwell of suflicient length over a sufficient period to procure the chilling of the casting in the mold.

A movable member 54 of the mold has complementary mold parts completing the mold with of the molding surfaces.

the cavity 25. This is provided with water cooling chambers 55 connected with a source of cooling liquid (not shown) The movable mold member is provided with a socket 56a which, with the mold closed, is directly opposite the charging passage 25a. This socket is connected by a lead 56 which connects the charging passage with the mold cavity. The socket 56a has its walls shaped to so engage the metal of the plug formed in the socket as to assist in withdrawing the casting from the stationary mold member. The mold member 54 is connected by straps, or plates 51 with a block 58 secured on the head 32 so that the mold member 54 reciprocates with the head. A knock-out block 59 is slidingly mounted in the space between the member 54 and the block 58 on pins 60 which extend from the member 54 to the block 58. Knock-out pins 6| and 62 extend from the knock-out block 59 through the mold member into position to engage the casting and discharge it from the mold. One of these pins 62 operates on the end of the plug formed in the socket 56a. Push rods 63 are slidingly mounted in perforations 64 in the head 32 and extend from the knock-out block 59. An abutment 65 issecured on the rod 29 preferably adjustable by means of a securing screw 66. A thrust pin 61 ex -ends from the knock-out block 59 through the mold member 54 and is positioned to engage the face of the mold member 24 as the head 32 with the mold member 54 is advanced.

The molding operation is as follows: The movable member 54 is moved forward, closing the mold. With this forward movement, the pin 61 engages the mold member 24 and arrests the knock-out block 59 so as to retract the knock-out pins 6| and 62 and bring them back to the faces After the mold is charged and the metal chilled the member 54 is retracted opening the mold and in this rearward movement the push rods 63 come into engagement with the abutment 65, thus arresting the knockout block 59 prior to the completion of the rearward movement of the mold member. With the continued movement of the mold member the push-out pins 6| and 62 are projected through the mold member 54, thus disengaging the casting from the mold after which the operation of closing the mold is. repeated.

The air on the cylinder is automatically controlled. A rock arm 68 is connected with the valve plug l5a. A rod 69 connects the arm 68 with a bell crank lever pivotally mounted or. a pin 1| in the frame. A rod 12 extends from the bell crank lever to a rock arm 13. The rock arm is mounted on a pin 14 mounted on the gear case 30. Rock arms and 16 are fixed with the rock arm 13 and provided with rollers 11 at their ends. A cam 18 is arranged on the end of the cran 1 42 and the rollers 11 are in the path of the cam 16 as the crank is rotated. As the mold is closed the crank reaches the arm 15 and throws, through the connecting mechanism, the valve plug l5 to connect the upper end of the cylinder with the air supply. The immediate downward movement of the piston and with it the plunger 8 charges the mold. After the mold is charged and at the completion of the dwell the cam 18 reaches the roller on the arm 16 and reverses the valve |5 so as to exhaust the upper end of the cylinder and connect the lower end of the cylinder with the air supply. The plunger 8 is then withdrawn and this withdraws the molten metal making the break somewhere in the charging tube 20, the exact position of the break depending somewhat The piston I is considerably larger than the plunger 8 so that there is a very decided pressure diflerential.- This may be made as much as desired depending on the available air pressure for operating the piston and the proper pressure to be exerted on the molten metal in the mold. This pressure is increased by the fact that after the extension I2 leaves the socket I3 the air flow on the piston is rapid and there is a very great acceleration of the piston so that it reaches the point where the mold is filled at a very considerable velocity and this gives to the metal as it fills the mold an added and final pressure shock through the inertia of the plunger and piston. In this way the mold is filled rapidly and with a very high final pressure.

It will be noted in the present structure that the mold has a fixed member and a movable member and that the knock-out action on the formed casting is'accomplished through a single reciprocating mechanism. Thus the operating mechanism is very much simplified.

This application is in part a continuation of application, Serial Number 627,195, filed by me Aug. 1, 1932.

What I claim as new is:

1. In a die casting machine, the combination of a mold; a molten metal supply receptacle; a fixed connection between the receptacle and the mold; a plunger cylinder in the receptacle having an inlet port for molten metal; a plunger in the cylinder operating over the port; a. power cylinder above the plunger cylinder; apiston operating in the power cylinder connected with the plunger; a cylinder extension of smaller diameter than the power cylinder; a piston extension operating in the cylinder extension and effecting the initial movement of the plunger, the piston completing the movement of the plunger, and forcing the molten charge into the mold; and means reversing the plunger to reverse the pressure on the connection to sever the molten metal from the metal of the mold.

2. In a die casting machine, the combination of a mold; a molten metal supply receptacle; a connection between the receptacle and the mold; means for forcing molten metal through said connection into the mold comprising a cylinder having a supply port leading from the receptacle and a plunger in the cylinder operating to force the metal from the cylinder through the connection into the mold; and means retarding the acceleration of the plunger during the closing of the port.

W. A. PARKER.

Images