US2912730A - Positioning or locking guides for dies - Google Patents

Description

A. F. BAUER POSITIONING OR LOCKING GUIDES FOR DIES 2 Sheets-Sheet 1 7 INVENTOR Alfred F. Bauer 1%? Nov. 17, 1959 I Filed Nov. 1, 1956 Maw?? n mm 5 mm (m ww wm Nov. 17, 1959 A. F. BAUER POSITIONING OR LOCKING GUIDES FOR DIES Filed Nov. 1, 1956 2 Sheets-Sheet 2 N am INVENTOR Alfred P. Bauer ORNEY United States Patent O POSITIONING oR LOCKING GUIDES FOR mus Alfred F. Bauer, Toledo, Ohio, assignor to National Lead Company, New York, N .Y., a corporation of New Jersey Application November 1, 1956, Serial No. 619,754

2 Claims. (Cl. 22-153) This invention relates to a device for positioning the two sections of a casting die. More specifically, this invention relates to a device for positioning and correctly aligning the two sections of a die block or permanent mold for producing castings from various materials.

In the production of castings from molten metal by the process of pressure die casting, two separable sections of a permanent metal die or mold containing the correct impression are used to impart the desired configuration to the finished casting. To obtain the proper configuration of the die cavity, some means must be employed to insure the correct alignment of the two separable sections of the die or mold. In order to maintain this alignment, some form of dowell or pin is generally used to locate one section in its proper position relative to the other section. Standard practice in the industry has been to incorporate round dowel pins in one section of the die or mold and a round opening usually fitted with a bushing in the mating section. When the metal has been injected the heat flows into the die halves and may heat them unevenly according to the shape of the cavity. The different heat conditions between both die halves are often corrected by adding water cooling systems. However, even the best cooling system does not guarantee uniform heat and temperature conditions in the two die halves. Therefore, they expand differently. On smaller dies this variation from one half to the other is taken care of by the clearance between dowel pin and bushing. On larger dies, however, this clearance would have to be so large that too much of a mismatch between one half of the cavity and the other would be encountered.

An attempt to compensate for this unequal expansion between the two sections has been made by positioning the dowels near the center of the die block. This posi tion for the dowels is undesirable inasmuch as it permits misalignment of the sections more readily than would positioning the dowels near the periphery of the die block. The proper positioning of round dowels presents an especially difficult problem when the longitudinal dimension of the die block greatly exceeds the transverse dimension or vice versa.

An object of this invention is to provide a type of positioning device which will assure alignment of die sections even when accompanied by the natural though unequal expansion of the sections. Another object of this invention is to provide a type of positioning device which will not be subject to excessive wear when placed near the periphery of large die blocks. A further object of this invention is to provide a type of positioning device which, in order to assure proper alignment, may be positioned near the periphery of die blocks whose longitudinal dimension greatly exceeds the transverse dimension and whose configuration will not cause binding, difiiculty of opening or uneven wear of the positioning device when the segments of the die block are subject to unequal expansion.

These and other objects of this invention will become apparent from the following more complete description and the drawings in which:

Fig. 1 is a face view of a typical holding block for one of the separable die halves having the guide blocks located at the corners.

Fig. 2 is a perspective view of a portion of two mating die sections partially separated.

Fig. 3 is a cross-sectional View of a portion of two mating die sections in the closed position.

Fig. 4 is a face view of another holding block for a die, in which the longitudinal dimension greatly exceeds the lateral, showing an alternate positioning of the guide members.

The guide members are indicated by the reference numeral 20 in Figs. 1, 2 and 3. These guide members have the general shape of right-angled parallelepipeds and are removably mounted in the body of the die or holding block 10 through mounting holes 16 by fastening screws 18 or by other suitable means. A portion of guide member 20 is recessed into the die body in cavity 12 such that bottom face 27, side faces 26, and back face 28 of the guide member are in juxtaposition respectively to end face 13, side faces 14 and front face 15 of die cavity 12. The projecting portion of guide member 20 is provided with mating faces 24 which are parallel to each other as well as being parallel to the longitudinal axis of the guide member and perpendicular to die face 11. The preferred form of guide member 20 has front face '21 parallel to die face 11 and has a taper surface provided at 22 for ease of mating of the guide memberand guide socket as the die halves are being closed.

The mating portion or guide socket 40 is shown in Figs. 2 and 3 as it is formed in the other die half 60. The sides of guide socket 40 consist of wear plates 44 which are removably attached into recess 49 by fastening bolts 50 or other suitable means in such a manner that side face 47 and back face 42 are in juxtaposition respectively to side face 54 and front face 56 of the recess. Clearance space 51 which permits the movement of guide member 20 relative to wear plate 44 is formed by the extension of wear plate 44 into guide cavity 41 beyond inner face 52 of the guide cavity. Guide cavity 41 is formed deep enough into die body 60 that clearance is provided between back face 43 of the guide socket 40 and front face 21 of the projecting guide member when the die assembly is in the closed position. Wear plates 44 are placed so that their inner faces 46 are parallel to each other and to the longitudinal axis of the guide socket 40 as well as being perpendicular to die face 61. Enough space is allowed between faces 46 of the wear plates so as to provide a snug fit between the wear faces 46' and mating faces 24 of the projecting guide member 20 when the die halves are in closed position.

The projecting guide members are normally affixed to that half of the die which is subject to the greater expansion and are arranged in paired relationship the two members of any one pair being located on opposite sides of the die cavity in such manner that an extension of the centerline of the two guide members forms a straight line. In a preferred embodiment the guide members are positioned on the die face at or near the periphery of the die section.

The guide sockets, also in paired relationship, are formed in the other die section being placed in corresponding locations such that when the die halves are closed to form the enclosed die cavity, the guide members match with and fit into the guide sockets. A snug fit is provided between the side faces 24 of the projecting equal to the lateral dimension between wear faces 46 of the guide socket. The longitudinal dimension of the guide socket, i.e. the dimension along the center line previously mentioned, however, is larger than is that of the projecting guide member and thus a clearance is provided between bottom face 27 of the guide member and the bottom of guide socket 40 so as to permit longitudinal movement of the projecting guide member relative to the socket. The term lateral movement refers to movement in a plane parallel to the parting line face of the die sections and in a direction radially from the center of the die face.

The preferred number of projecting guide members and corresponding guide sockets is four, arranged in two pairs. These guide members may be located at the four corners as shown in Fig. 1 or intermediate of the corners as shown in Fig. 4. The latter arrangement is the preferred form only when the length of the die greatly exceeds the width or vice versa. With either method of locating the guide members, the operation is the same. The snug fit between the sides of the projecting guide member and the sides of the mating socket prevents lateral or sideways movement of the guide member with respect to the guide socket and vice versa. As a result, movement of one die half with respect to the other half in any direction other than radially from the center of the die face is prevented. At the same time, since clearance is provided along the longitudinal axis of the guide members, i.e. between the ends of the projecting guide member and its mating socket, movement of any of the guide members relative to its mating socket is possible in a radial direction from the center of the die face, therefore, permitting expansion of one die half to be greater than that of the other.

Expansion of a die, caused by heating, is outward from the center in all directions. By positioning the guide as shown in Figs. 1 or 4, movement of one die relative to the other, which may be caused by the unequal expansion of the two die halves, is permitted in all directions radially from the center. At the same time, the configuration of the guide members will permit no tangential movement. As a result, the two halves of the die cavity are kept in perfect alignment and the guide members are not subject to the excessive strain and Wear which would be encountered if these guide members were the customary round dowels and round holes.

It is understood that the apparatus shown for the accomplishment of locating or locking two separable die sections in proper alignment with respect to each other is susceptible to considerable modification. Therefore, the form of the invention described above should be considered as illustrative and not limiting the scope of the following claims.

I claim:

1.1m combination a die assembly comprising two separable die sections forming therebetween, when closed, a die cavity, each of the two separable die sections being subject to a different degree of heat with a resultant diiferent amount of radial expansion, and means for maintaining said sections in accurate alignment during closing and when closed, said means including at least two projecting guide members of substantially rectangular cross-section positioned in the body of one of said die sections and projecting laterally from the face of said section, the projecting guide members being located on opposite sides of the die cavity in such a manner that an extension of the centerlines of two opposing guide members forms a straight line passing through the center of the face of the die section, and at least two matching guide sockets of substantially rectangular cross-section positioned in the body of the other die section and extending below the face thereof, the lateral dimensions normal to said center line of both the projecting guide members and the guide sockets being substantially identical, the longitudinal dimension along said center line of the guide socket being greater than that of the matching projecting guide member such that a substantial clearance is provided between the guide member and socket along the center line, the guide members fitting into the guide sockets when the die sections are closed.

2. Apparatus according to claim 1 wherein two pairs each of projecting guide members and guide sockets are employed.

References Cited in the file of this patent UNIT ED STATES PATENTS 237,619 Smith Feb. 8, 1881 1,082,120 Hanstein Dec. 23, 1913 2,214,998 Hogemeyer Sept. 17, 1940 2,218,195 Garrett Oct. 15, 1940 2,319,479 Ryder May 18, 1943 2,456,113 Dorner Dec. 14, 1948 2,530,760 Coulthard Nov. 21, 1950 2,572,984 Byers Oct. 30, 1951 FOREIGN PATENTS 4,598 Great Britain Mar. 4, 1 901

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