Patent GB-751379-A (GB)
Title: Improvements in or relating to casting of v-type internal combustion engine cylinderblocks
IPC: B22D15/02
Filed: 1954-02-10
Abstract: 751.379. Cores. GENERAL MOTORS CORPORATION. Feb. 10, 1954 [Feb. 26, 1953], No. 3876/54. Class 83 (1). A core-assembly for casting a V-type internal-combustion engine cylinder - block comprises a sand-core having a number of angularly-disposed cylinderdefining portions and water-jacket sand cores having for each cylinder-defining portion a bore that surrounds the portion and forms an annular space therewith. For a sixcylinder engine the core-assembly consists of three cylinder-bulkhead cores 76, 78, 80, each respectively comprising a triangular-section bulkhead-portion 86, 88, 90, and a pair of cylinder-defining portions 92, 94, and two water-jacket cores 82, 84, each. having three bores 96, 98 respectively therein adapted, preferably with the use of metal spacerrings 114, to coaxially surround the cylinder-portions 92, 94 The cores are assembled in the lower half of a transfer-fixture, Fig. 6, the bulkhead cores being held in abutting relationship by having their lower ends positioned in a recess 112 formed by a frame 110 on the base-plate 100 of the transfer-fixture. The cylinder portions 92, 94 are of sufficient length to extend through the respective bores in the water-jacket cores 82, 84. The upper half 115 of the transfer-fixture, which includes a frame 116 having apertures 118 for dowels 108 projecting from the lower half of the fixture, is then placed in position over the lower-half and the core-assembly, which is temporarily secured to the upper-half 115 by retractible-pins 126, 128, 142 (not shown) which slide in blocks 124, 120, 140 attached to the upper-half, and engage holes 152, 150, 154 respectively in the cores. The upper-half and core-assembly are removed from the lower-half of the base-fixture and transferred to the draghalf 159, Fig. 10, of a metal flask, the apertures 118 in the upper-half 115 fitting over dowels 180 on the drag-half. The bases of the cylinderbulkhead-cores 76, 78, 80 rest on the bottom of the mould-cavity in the sand in the drag-half, and core-projections 162 on the water-jacket cores are supported by core prints 160. A sprue-core 168 is inserted in the drag-half and a vertical groove 173 co-operates with a similar groove in the end-wall of the mould-cavity to form a sprue for the molten metal. After the retractible pins 126, 128, 142 are withdrawn from their holes in the cores, the fixture upperhalf 115 is removed to leave the core-assembly in the drag-half as shown in Fig. 10. The spacer-sleeves 114 are then withdrawn and the cope-half 188, Fig. 11, of the flask is positioned over the drag-half 159, being aligned therewith by dowels 180. The mould and core is then ready for casting, a sprue formed in the sand in the cope connecting with the sprue in the draghalf. The water-jacket cores 82, 84, and the cam-shaft gallery defining portions 196 of the bulkhead-cores are positioned by core-locators 192, 194, 198, respectively. Vertical vents 216 in the cope communicate with the openings 150 communicating via passages 218 with a longitudinal lower-vent 220. Longitudinally-extending gates 224 are formed in the bottom portions of the cores 76, 78, 80.