US3165796A

US3165796A - Large angular core locking mechanism for die casting

Info

Publication number: US3165796A
Application number: US171715A
Authority: US
Inventors: John W Mcdonald
Original assignee: Nat Lead Co
Current assignee: NL Industries Inc
Priority date: 1962-02-07
Filing date: 1962-02-07
Publication date: 1965-01-19
Anticipated expiration: 1982-01-19
Also published as: CH395438A; GB956546A; LU42717A1

Description

Jan. 19, 1965 J. w. MCDONALD 3,165,796

LARGE ANGULAR com: LOCKING MECHANISM FOR DIE CASTING Filed Feb. 7, 1962 2 Sheets-Sheet 1 INVENTOR. JOHN W MCDONALD QQQK ATTORNEYS Jan. 19, 1965 J. w. MCDONALD LARGE ANGULAR CORE LOCKING MECHANISM FOR DIE CASTING 2 Sheets-Sheet 2 Filed Feb. 7, 1962 INVENTOR. JOHN W. MCDONALD AT TORNEYS United States Patent- O 3,165,796- LARGE ANGULAR CORE LOCKING MECHANISM FOR DE CASTING .lohn W. McDonald, Toledo, Ohio, assignor to National Lead Company, New York, N.Y., a corporation of New Jersey Filed Feb. 7, 1962, Ser. No. 171,715 Claims. ((11. 22-93) This invention relates to a core locking mechanism for a die casting machine and in particular to a means of constraining large angularly-disposed core members or slides which means utilizes the casting machine toggle linkage as a part of the locking mechanism.

Large movable die cores and slides must be held against the very high metal pressures of modern die casting machines or they will be moved out of position, resulting in an imperfect casting. Forces in the order of 500,000 to 1,000,000 pounds on such large members are not unusual. Heretofore, a simple wedge, or modification thereof, mounted on the cover die has been satisfactory for locking cores and slides operating in the die parting plane (i.e., a plane at right angles to the principal direction of movement of the ejector die and sliding plate) or at small angles thereto. In some instances, this wedge has been used to supply the force which reciprocated the core or slide, while in other instances the wedge has been used to do only the locking of the core or slide with the reciprocating motion supplied by a separate hydraulic cylinder. On small cores or slides the hydraulic cylinder often has sufiicient force to hold the member against the impact of the molten metal without employing any auxilia1y mechanical lock.

With cores or slides disposed at a relatively large angle to the parting plane, a wedge extending from the cover half of the die (stationary half) has been recognized as inadequate as the core or slide has an appreciable me chanicaladvantage against the wedge. Hence, it has been the practice to hold movable angular members in the ejector die half by-additional mechanisms, not a part of the machine. Additional hydraulic cylinders had to be provided to impart the necessary reciprocating motion to the added holding mechanisms.

The present invention provides a new mechanism in which the movable core members are reciprocated by a hydraulic cylinder and locked mechanically directly by the machine linkages without the necessity of employing any auxiliary mechanism. The mechanical locking is accomplished as the die closes to render the over-all operation as simple and rapid as possible.

It is, therefore, a principal object of the invention to provide .a die casting machine with improved operating mechanism for moving the ejector die into position and for locking large angularly disposed core members securely in place simultaneously in one operation.

Other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawing, in which:

FIG. 1 is a somewhat schematic view with parts broken away and with parts in vertical cross section of a die casting machine embodying the principles of the invention,

the dies of the machine being shown in an open position;

FIG. 2 is a view similar to FIG. 1 but with the dies of the machine in a closed and locked position, ready to receive a shot of molten metal; and

FIG. 3 is a detailed, fragmentary view taken along the line 33 of FIG. 2.

Referring to the drawings and more panticularly to FIG. 1, a die casting machine indicated at 18 includes rails 12 which support a stationary front plate 14 and slidably support a rear plate 16, through which machine 7 Bihfifldh Patented Jan. 19, 1965 "ice tie bars 18 extend to serve dually as guides therefor. The front plate 14 supports a cover die holding block 20 on which is mounted a cover die 22. The rear plate 16 supports an ejector die holding block 24, in which is positioned an ejector die 26- which, in cooperation with the cover die 22, forms a die cavity 28 (FIG. 2) when moved into registry therewith.

Movement of the ejector die 26, the ejector die holding block 24, and the sliding plate 16 is effected by mechanism located to the rear of the plate 16, which mechanism is mounted on a crab 30. The crab 30 is held in fixed relationship with respect to the front plate 14 by being adjustably afiixed to the machine bars 18. A bydraulic closing cylinder 32 is supported by the crab 30 parallel to the rails 12 and includes a piston 34 and a Trains of linkages are pivotally connected to the crosshead 38, to ears'40 of the crab 30, and to the sliding plate 16 to effect movement of the latter when the crosshead 38 is moved by the hydraulic closing cylinder 32. The trains of linkages include crosshead links 42 which are pivotally connected to the crosshead 38 by pivot pins 43 at portions thereof spaced apart in a direction laterally of the movement of the crosshead'38. The opposite ends of the links 42 are pivotally connected by pivot pins 44 to inwardly extending portions 45 of intermediate links 46, which are pivotedby pins 47 at their opposite ends to the cars 40 of the crab 30. The trains of linkages also include sliding plate links 48, intermediate points of which are pivotally attached by pins 49 to the sliding plate 16. Rear end portions of the links 48 are pivotally attached by pins 50 to the intermediate links 46, at or near the pivot pins 44 for the crosshead links 42 and spaced substantially from the pivot pins 47 at the ears 40. In accordance with the invention, the plate links 48 have extensions 51 which constitute portions elfective to move and to lock core members for the die cavity 28.

The die cavity 28 may take any suitable form, but for purposes of illustrating the present invention, a die for forming a multi-cylinder V engine block has been shown. For this purpose, the cavityhas core members 52, one for each combustion engine cylinder bank, which extend into the die cavity in pairs, at angles to one an-. other when the die isclosed and which are withdrawn following an opening movement of the die. The core members 52 extend outwardly beyond the cavity 28 and the ejector die holding block 24 to connecting plates 54 which are located to the rear and on each side of the holding block 24. Behind the connecting plates 54 are core cylinders 56 containing pistons 58 and piston rods 6%} which are aflixed to the plates 54 on the side opposite the core members'52. The cylinders 56 can be connected through lines 62 to a suitable source 64 of fluid under pressure ,to supply fluid to. the cylinders and to move the pistons 58 rearwardly therein. If the cylinders are made double acting and are supplied'with suitable conventional valving, the cylinders can be used both to seat the core members 52 in the die and to remove the core members after a shot has been made.

On each side of the cylinders 56, and fixed to the plates 54, are lock rods 66 (see upper part of FIG. 1 and FIG. 3) which are moved into abutting relationship with the link extensions 51 to lock the core members 52 into the die cavity 28 when the ejector die 26 is in closed position with respect to the cover die 22. This is accomplished as follows: Assuming the casting machine 18 is in the open position, as shown in FIG. 1, hydraulic fiuid is supplied to the blind end of cylinders 56 which advance the lock rods 66, the plates 54 and the core members 52 'until the core members 52 reach their proper position in die cavity 28 and the plates. 54 are in contact with crosshead bar or piston rod 36 connected to a crosshead the ejector die holding block 24 (FIG. 2). With all cores and slides in the casting position, hydraulic fiuid can be supplied to the blind end of the cylinder 32 to move the piston 34 out of the cylinder and to move the crosshead 38 toward the front plate '14. As this movement begins, the crosshead links 42 begin to move outwardly, the upper one in a clockwise direction and the lower one in a counterclockwise direction, as viewed in FIG. 1. The intermediate links 46 also begin to pivot about the pins 47 at the cars 40, the upper one in clockwise direction and the lower one in a counterclockwise direction, and the sliding plate 16 begins to move toward the front plate 14. During the initial part of the plate movement, the plate links 48 do not rotate at all. However, as pivoting of the intermediate links 46 continues, the plate links 4-8 begin to pivot about the pins 49, the upper link 48 moving counterclockwise and the lower link moving clockwise. This causes the core-actuating extensions 51 to move toward the lock rods 66. The actions of these various components continue until the ejector die 26 moves into registry with the cover die 22. At this time, the core-actuating extensions 51 of the links 48 have moved into grooves 68 in the rear plate 16 to lock the core members 52 properly within the cavity 28. The crosshead links 4-2 also have moved into vertical alignment, and the crosshead 3S abuts a stop 70.

Thus, it will be seen that the core members 52 and the ejector die 26 are all locked and constrained in one simultaneous operation and single movement of the crosshead38; With the crosshead links 42 in vertical alignment, the link trains are positivelylocked against further movement until the crosshead 33 is again moved outwardly. This assures that the ejector die 26 is locked against movement away from the cover die 22 due to the high pressure of molten metal in the die cavity 28 and also assures that the core members 52 cannot possibly move out or" the die cavity 28 under the casting pressure because the core-actuating portions 51 of the links 48 bear positively against the lock rods 66.

Although not constituting part of the invention, the die cavity components also include outer core components 72 which are moved into and out of position by hydraulic cylinders 74, the components 72 being locked in place when in position by conventional wedge locks 76 in the cover die holding block 29 which cooperate with recesses '78 in the components '72. A conventional locking arrangement is thus available for the core components '72 so that additional locking linkages are not necessary for them.

Whenthe core members '52 and the components 72.

are in position, and the ejector die-26 is in register with the cover die 22, metal is forced into the die cavity 23 from a shot sleeve 80 by a shot plunger 82 operated by a hydraulic shot cylinder 84, the molten metal being introduced into the shot sleeve 82 through a suitable pour opening 86.

After the metal is cast, the sliding plate 16, the ejector die holding block 24,;and the ejector die 26 are retracted from the cover die 22 and the cover die holding block 2% by the crosshead 38. This is accomplished by supplying hydraulic fiuid to the rod end of the piston 34 to retract the crosshead 38 and thereupon move the various link trains from the positions of FIG. 2 to the positions of FIG. 1. At this time, hydraulic fluid is supplied to the rod end of the

cylinders

56 and 74 to move the core members 52 and the components 72 outwardly once again. The completed engine block die casting is then ejected from the ejector die by suitable ejector pins (not shown) controlled by means of an ejector box 88 and an ejector drive 9%, as is known in the art.

Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art for accomplishing the same objectives. It is to be understood that such modifications can be made without departing from the scope of the invention it such modifications are within the spirit and tenor of the accompanying claims.

I claim:

1. In a die casting machine, a stationary plate, a cover die supported by said plate, a sliding plate, an ejector die supported by said sliding plate, said cover die and said ejector die forming a die cavity when said ejector die is moved into register with said cover die by said sliding plate, a core member adapted to extend into said cavity, means for moving said core member out of said die cavity, and means for locking said core member in said die cavity, said locking means comprising a pivotal link, means for pivotally supporting said link on said sliding plate in predetermined relationship with respect to said core member, said link having a portion effective to lock said core member in said die cavity, a crosshead, means for moving said crosshead toward and away from said stationary plate, and means connecting said crosshead and said link to push said sliding plate toward said stationary plate, to cause said link to pivot as said crosshead and said sliding plate move toward said stationary plate, and to cause said link to lock said core member in said cavity as said sliding plate moves toward said stationary plate.

2. In a die casting machine, a stationary plate, a cover die supported by said plate, a sliding plate, an ejector die supported by said sliding plate, said cover die and said ejector die forming a die cavity. when said ejector die is moved into register with said cover die by said sliding plate, a pair of core members adapted to extend into said cavity, means for moving said core members out of said die cavity, and means for locking said core member in said die cavity, said locking means comprising a pair of plate links, means for pivotally supporting said links on said sliding plate in predetermined relationship with respect to said core members, said plate links having portions effective to lock said core members in said die cavity, a crosshead, means for moving said crosshead toward and away from said stationary plate, and means connecting said crosshead and said plate links to cause said links to pivot as said crosshead and said links move said sliding plate toward said stationary plate and to cause said links to lock said core members in said cavity as saidsliding plate moves toward said stationary plate.

3. In a die casting machine, a stationary plate, a cover die supported by said plate, a sliding plate, an ejector die supported by said sliding plate, said cover die and said ejector die forming a die cavity when said ejector die is moved into register with said cover die by said sliding plate, a pair of angularly-disposed core members adapted to extend into said cavity, means for moving said core members out of said die cavity along angularly disposed paths, and means for locking said core members in said die cavity, said locking means comprising a pair of plate links pivotally attached to said sliding plate in predetermined relationship with respect to said core members, said plate links having portions effective to lock said core members when said portions intersect the paths of said core members, a crosshead, means for moving said crosshead toward and away from said stationary plate, and link means connecting said crosshead and said plate links to cause said plate links to pivot as said crosshead and said plate links move said sliding plate toward said stationary plate whereby said portions of said plate links move into the paths of said core members to lock said members into said cavity as said sliding plate is moved toward said stationary plate.

4. In a die casting machine, a stationary plate, a cover die supported by said plate, a sliding plate, an ejector die supported by said sliding plate, said cover die and said ejector die forming a die cavity whensaid ejector die is moved into register with said cover die by said sliding, plate, a pair of angularly disposed core members adapted to extend into said cavity, connecting plates attached to outer ends of said core members, hydraulic cylinder means connected to said plates between said core members for moving said core members from said cavity, lock rods extending outwardly from said connecting plate on each side of said cylinder means, and means for locking said core members in said cavity comprising a pair of links, means for pivotally supporting said links in predetermined relationship with respect to said lock rods, said links having portions eliective to contact said lock rods, 2. crosshead, means for moving said crosshead and said sliding plate toward and away from said stationary plate, and means connecting said crosshead and said links to cause said links to pivot as said crosshead and said sliding plate move toward said stationary plate and to cause said links to contact said lock rods and to lock said core members in said cavity when said sliding plate is moved toward said stationary plate.

5. In a die casting machine, a stationary plate, a cover die supported by said plate, a sliding plate, an ejector die supported by said sliding plate, said cover die and said ejector die forming a die cavity when said ejector die is moved into register with said cover die by said sliding plate, two groups of angularly-disposed core members adapted to extend into said cavity, a connecting plate attached to outer ends of said core members of each of said groups, hydraulic cylinder means including pistons and piston rods, means connecting said piston rods to said connecting plates between said core members and means supplying hydraulic fluid to said cylinder means to move said core members into said die cavity and to withdraw said core members from said die cavity along angularlydisposed paths, and means for locking said core members in said die cavity, said locking means comprisinga pair of plate links, means for pivotally supporting said plate links on said sliding plate in predetermined relationship with respect to said core members, said plate links having portions eifective to engage and to lock said core members in said die cavity, irrespective of any force derived from said hydraulic cylinder means, a crosshead, means for moving said crosshead toward and away from said stationary plate, and link means connecting said crosshead and said plate links to cause said plate links to pivot as said crosshead and said plate links move said sliding plate toward said stationary plate and to cause said plate links to contact said connecting plates and to lock said core members in said cavity as said sliding plate moves toward said stationary plate when said crosshead and said link means have moved substantially into alignment.

References Cited by the Examiner UNITED STATES PATENTS 1,579,938 4/26 Hotter 22-93 1,595,316 8/26 Sampson 22-93 1,607,677 11/26 Korsmo 22--93 1,974,822 9/ 34 Lannert 22-93 2,172,798 9/39 Littman 2293 2,214,638 9/40 Kux 2293 MICHAEL V. BRINDISI, Primary Examiner.

MARCUS U. LYONS, Examiner.

Claims

1. IN A DIE CASTING MACHINE, A STATIONARY PLATE, A COVER DIE SUPPORTED BY SAID PLATE, A SLIDING PLATE, AN EJECTOR DIE SUPPORTED BY SAID SLIDING PLATE, SAID COVER DIE AND SAID EJECTOR DIE FORMING A DIE CAVITY WHEN SAID EJECTOR DIE IS MOVED INTO REGISTER WITH SAID COVER DIE BY SAID SLIDING PLATE, A CORE MEMBER ADAPTED TO EXTEND INTO SAID CAVITY MEANS FOR MOVING SAID CORE MEMBER OUT OF SAID DIE CAVITY, AND MEANS FOR LOCKING SAID CORE MEMBER IN SAID DIE CAVITY, SAID LOCKING MEANS COMPRISING A PIVOTAL LINK, MEANS FOR PIVOTALLY SUPPORTING SAID LINK ON SAID SLIDING PLATE IN PREDETERMINED RELATIONSHIP WITH RESPECT TO SAID CORE MEMBER, SAID LINK HAVING A PORTION EFFECTIVE TO LOCK SAID CORE MEMBER IN SAID DIE CAVITY, A CROSSHEAD, MEANS FOR MOVING SAID CROSSHEAD TOWARD AND AWAY FROM SAID STATIONARY PLATE, AND MEANS CONNECTING SAID CROSSHEAD AND SAID LINK TO PUSH SAID SLIDING PLATE TOWARD SAID STATIONARY PLATE, TO CAUSE SAID LINK TO PIVOT AS SAID CROSSHEAD AND SAID SLIDING PLATE MOVE UPWARD SAID STATIONARY PLATE, AND TO CAUSE SAID LIJK TO LOCK SAID CORE MEMBER IN SAID CAVITY AS SAID SLIDING PLATE MOVES TOWARD SAID STATIONARY PLATE.