US1950568A - Die casting machine - Google Patents

Description

March 13, 1934. D. RICHARDS DIE CASTING MACHINE Filed Oct. 2, 1933 5 Sheets-Sheet 1 NEE INVEN 7'0/7 March 13, 1934. D RICHARDs 1,950,568

DIE CASTING MACHINE Filed Oct. 2, 1933 5 Sheets-Sheet 2 March 13, 1934. o. RICHARDS DIE CASTING MACHINE Filed Oct. 2, 1933 5 Sheets-Sheet 3 5 Sheets-Sheet 4 HYVEHTOH March 13, 1934. o. RICHARDS DIE CASTING MACHINE Filed Oct. 2, 1933 Mam}?! H934}- n. RICHARDS 95495 1 DIE CASTING MACHINE Filed Oct. 2, 1935 5 Sheets-Shet 5 Patented Mar 13, 1934 Uhiiil Application Dctober 2, 1933, Serial No. 691,857 In Great Britain December 29, 193i 6 Claims.

This invention relates to die casting machines in which a carrier is used to transfer molten metal from the furnace and particularly to electrically operated die casting machines, and has for its object to introduce an improved construction of machine suitable for pressure die casting in metals of low or high melting point, and particularly designed for speedy and accurate production of castings, and for elirmnating or reducing to a minimum the amount of surplus metal which has to be re-melted, and the use of tie rods between the die carriers.

According to this invention the metal in the metal carrier is completely sealed in its passage from the furnace to the die. For this purpose the lower portion of the metal in the furnace is transferred directly to a metal carrier that is provided with a movable cover plate and conveys a measured quantity of metal in a sealed condition from the furnace opening to a plunger for ejecting the metal into the die.

The machine when actuated electrically co1nprises a framework or bed having two raised ends of which one serves as a support for a solenoid actuated plunger and a stationary die carrier plate which is adjustable for different lengths of metal carriers and may be water circulated for cooling purposes through a passage formed in the die carrier plate, and the other serves as a support for a traversing die carrier plate and a solenoid that is used for closing its die against the die in the stationary die carrier plate. The body of the bed accommodates a solenoid for withdrawing the plunger from the die moving a metal carrier to the discharge orifice of an electrically heated furnace for receiving a charge of molten metal which is subsequently interposed between the die in the stationary die carrier and the end of the plunger and is completely sealed in its passage from the furnace to the die so that oxidation of the metal is prevented. The machine is constructed in such manner that it will perform one cycle of operations, and then stop, or run u continuously at will. If desired compressed air 0 cylinders, or hydraulic power can be substituted for the solenoids.

In the accompanying drawings:

Fig. 1 is a side elevation of the furnace end of an electrically actuated die casting machine constructed in accordance with this invention, and with the front side of the machine removed.

Fig. 1 is a detached View showing a telescopically arranged plunger.

55 Fig. 2 is a section, partly in elevation, of the movable die end of the machine substantially on line 2--2 of Fig. 3.

Figs. 3 and 4 are sections looking in the direction of the arrows 3 and 4 in Fig. 1.

Fig. 5 is a plan of the furnace end of the machine.

Fig. 6 is a plan of part of Fig. 5 with the furnace and solenoid removed.

Fig. '5 is a plan of he movable die end of the machine.

Fig. 8 is a section showing an enlarged view of the metal carrier and its cover plates, and

Figs. 9 and 1c are detached views of a trip mechanism for locating and releasing the metal carrier plate.

A indicates the traversing die carrier plate, B the stationary die carrier plate, C the plunger that is actuated by the solenoid (1 D the solenoid for closing the die in the plate A against the die in the plate B, E the solenoid for withdrawing the plate A from the plate B, F the metal carrier, and G the furnace.

Pivoted to a casting a that is attached to the movable die carrier plate A is a pair of links a that are hinged by pins a to one pair of arms a of two bell crank levers that are pivotally mounted on lugs a on the casing of the die closing solenoid D. The other pair of arms a of the bell crank levers are connected by links a and pins a, levers a a that are rigidly fixed on a shaft H that extends transversely across the machine and is free to turn in bearings on the machine frame. Pivoted on the pins a are two rods a the'free ends of which pass through holes in collars a on the pins a and enter holes in the latter. Screwed into these holes are screw plugs 0, which form adjustable abutments for the rods a to abut against just before the links a and arms a of the bell crank levers, in which position the rods a bring the links a and arms a into a straight line and give a final lock to the toggle joint made by the links a and the arms a of the bell crank levers. Formed in a piece with the arm a is another arm 6 that is attached by a rod 6 to one end of the core of the solenoid E that retracts the movable die carrier plate A from the stationary one B. Extending from the solenoid core at its other end is a rod 0 that is connected by a link 0 and pin 0 which is formed with an extension 0 to a lever c fulcrumed on a shaft 0 that extends transversely across the machine framework. The upper end of the aforesaid lever is forked and carries a pawl c that engages a snail cam c" that is secured to the aforesaid shaft 0 upon which is also secured a lever 0 The end of this lever is connected by a link 0 to a lever c which is fulcrumed at e and is connected at its other end by a pair of links 0 to the moving core of the plunger operating solenoid C The pawl c is provided with a tail piece 0 for engagement with an adjustable stop 0 which is carried in a bracket 0 in the machine framework. The pawl c is provided with a tail piece e for engagement with an adjustable stop 0 which is carried in a bracket 0 in the machine framework. The pawl c is tripped at the end of the first half of the stroke of the solenoid E by engagement of the tail piece 0 with the stop 0 during the opening operation of the die just prior to the raising of the metal carrier F. Situated parallel with the link 0 is a rod 1 slidably mounted in bearings f on the machine frame and provided with adjustable stops or collars f f that engage with the extension 0 of the pin 0 The slidably mounted rod 1 is coupled by a link i to one arm of a bell crank lever, the other arm I of which is connected by a link I to a plate i to which the metal carrier F, Fig. 8 is attached. The metal plate f is free to slide in guides f fixed to or forming part of a plate I that comes flush with the delivery outlet of the furnace G. The metal plate i is formed with an aperture i corresponding in size to the furnace delivery outlet and adapted to be moved into and out of line with the latter. Attached to the metal plate f by screws f is the metal carrier F which comprises a flanged tubular fitting, the bore of which corresponds in size to the aperture and registers with it. Attached to or forming part of the metal carrier F are guiding surfaces i in which a cover plate i is slidably mounted and retained in intimate contact with the end of the metal carrier by strong blade springs f mounted in recesses in the plate f. A tight joint is made between the working faces of the plates i F by means of spring pressed rollers I" which bear against the metal carrier or plate f When the parts are in the position shown in Fig. 81 the metal carrier F is charged with metal from the furnace G.

In operating the machine a switch (not shown) is first actuated tobring the solenoid D into action for traversing the movable die carrier A and closing the die (not shown). This movement of the movable die carrier pulls out the core of the solenoid E and causes the rod 0 and link 0 to turn the lever 0 until its pawl 0 passes the step of the snail cam c and the extension 0 of the pin 0 on the lever c engages the stop f on the rod 1 and retracts the latter thereby operating the connections f to f and the plate to lower the latter and metal carrier F to bring a charge of molten metal opposite to the plunger C. During this movement the lower edge of the cover plate f strikes against the top of a tubular fitting b that is fixed in the stationary die carrier plate B with its bore in line with the end of the plunger C. The movement of the cover plate is therefore arrested and the metal carrier continues to descend until it comes to rest in a pocket b in the tubular fitting b. The final alignment of the metal carrier F with the tubular fitting b and plunger C is effected just before the die is closed and before the plunger C is actuated. This is effected by an adjustable stop J on the movable die carrier plate coming into contact with one end of a rod 7' that is slidably mounted in the die carrier plate B and framework. The rod 7' then receives an endwise movement and turns a twoarmed lever 9' to lift a catch 1' thereon out of engagement with one arm 7' of a two-armed lever, the arm 9' of which is forked to embrace a spring controlled locating pin 9' that is formed with a tapered end to enter a tapered hole 7' in the plate f and thereby correctly align the metal carrier with the plunger C and tubular fitting b. Another switch (not shown) is now operated to cause the plunger C to force the charge of molten metal through the carrier F into the dies. Towards the end of the plunger movement a projection 7 (Fig. l) on the lever 0 comes in contact with a projection 7' (Fig. 9) on the arm 7' forcing the latter under the catch 7 and withdrawing the locating pin 7 from the tapered hole 7' in the plate i A third switch (not shown) is now actuated to bring the die opening solenoid E into action to open the discs. The core rod 0, link 0 are moved out to turn the pawl carrying lever c to turn the shaft 0 to retract the plunger C until the tail piece 0 of the pawl 0 comes against the adjustable stop 0 to disengage the pawl from the snail cam 0''. Further outward movement of the core rod 0 causes the pin extension 0 to engage the collar 1 on the slidable rod 7 and actuate the latter to raise the metal carrier plate f to the furnace orifice ready for the next cycle of operations through the connections f to 1. During the upward movement of the metal carrier F the plate I comes into contact with a pin b and is moved back to close the end of the metal carrier F. The die closing solenoid D is adjustable along the machine framework to suit various lengths, or thicknesses of dies. This adjustment is effected by a centrally disposed screw (1 (Fig. '7) rotatable in the framework and engaging a tapped lug d on the solenoid casing. Other screws (2 pass through tapped bosses in the framework and are set up against lugs d on the solenoid casing in any of its adjusted positions to receive the end thrust that is exerted during the die casting operation, the position of the screws being maintained by lock nuts d Abutments b (Fig. 4) on the carrier plate B are provided to abut against similar abutments on the raised portion of the framework to prevent the plate B from being forced backward by the pressure in the die. A hand control may be provided for traversing the movable die carrier plate A in either direction by hand. In the example shown this is effected by fixing a toothed sector K on the shaft H and mounting a pinion k on a shaft k that is rotatable in bearings on the machine frame and provided with a squared or other suitably shaped end for turning purposes. If desired the shaft may be slidably mounted for taking the pinion 7c out of gear with the sector K. Instead of the plunger C being made in one piece it may comprise two telescopic portions C C Fig. 1

normally held apart by springs C which keep their ends flush. When the solenoid is started to force the metal from the metal carrier F into the tubular fitting b the outer member C is arrested by such fitting. The inner telescopic member C continues to move forwards, and compresses the springs C and forces the molten metal through the tubular fitting b into the dies to apply the final pressure. By the use of a telescopic plunger a solenoid of smaller power can be used to apply the same amount of pressure to the molten metal in the die, a larger quantity of metal can be carried in the metal carrier by increasing its bore without altering the length. Instead of the die carrier and cover plate moving with a straight line motion they may be mounted on pivoted arms and move through an arc of a circle. The switches for operating the solenoids may be actuated separately by hand, or they may be controlled by cams to start and stop the solenoids in sequence during the cycle of operations and to cause the machine to run intermittently, or continuously. The dies may be secured to their respective plates by clamping blocks arranged somewhat in the manner of the jaws of a chuck. The metal carrier may be electrically heated to keep the charge of metal hot during its transference from the furnace orifice to the die.

By constructing a machine in the manner described a clear working space is provided for manipulating the dies and tie rods which cross the opening between the two die carrier plates are dispensed with.

What I claim as my invention and desire to secure by Letters Patent in the United States 1. In a die casting machine a plunger for ejecting molten metal into a die, said plunger comprising two telescopic portions so arranged that when the end of one telescopic portion comes to rest against a stop, the other telescopic portion continues its movement and applies the final pressure.

2. In an electrically operated die casting machine, a solenoid actuated plunger, a stationary die carrier plate, a traversing die carrier plate, a solenoid for closing the die in the latter against the die in the stationary die carrier plate, a solenoid for retracting the traversing die carrier plate from the stationary one, the said solenoid also withdrawing the plunger from the die and moving a metal carrier to the discharge orifice of an electrically heated furnace for receiving a charge of molten metal which is subsequently interposed between the die in the stationary die carrier and the end of the plunger.

3. In a die casting machine, a die carrier plate, a melting furnace, a carrierfor molten metal movable between said furnace and die carrier plate for registry with the furnace outlet in one position and with the die carrier plate inlet in another position, and means on said carrier for closing the furnace outlet when the carrier moves to the die carrier plate inlet.

4. In a die casting machine, a melting furnace, a carrier for molten metal movable into registry with the furnace outlet to receive a charge therefrom, a die carrier plate having an inlet, a movable closure on said metal carrier, means for moving said metal carrier into registry with said die carrier plate inlet, and means for opening said movable closure as the metal carrier moves into registry with the die carrier plate inlet.

5. In a die casting machine, a melting furnace, a carrier for molten metal movable into registry with the furnace outlet to receive a charge, a closure for said carrier, a die carrier plate having an inlet, means for moving said metal carrier into registry with the die carrier plate inlet, and means on said die carrier plate for opening the metal carrier closure as the metal carrier moves into registry with the die carrier plate inlet.

6. In a die casting machine, melting means,

charge transfer movement, and said closing 11;:

means being operable to open position by contact with said die holder means.

DANIEL RICHARDS.

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