Casting die with changeable male and female die cores

[0001] 1. Field of the Invention

[0002] The present invention relates to a press casting die, and especially to a brand new structure of a press casting die with changeable male and female die cores.

[0003] 2. Description of the Prior Art

[0004] The technique of press casting with a die is a conventionally used technique in manufacturing industry, e.g., using zinc magnesium alloy to produce an electronic housing with high quality, needs only to have a die well designed, the alloy can be injected with high pressure into the die to produce an article very fast. A conventional press casting die generally has a die seat at a stationary side and a die seat at a movable side thereof; the die seat at the stationary side is fixed, while the die seat at the movable side can be assembled in a movable mode, the movable side can move closer to or away from the stationary side along its moving direction to do the processes of die closing, injection and die releasing etc.

[0005] FIG. 1 shows a conventional press casting die, in which a die seat 91 at a stationary side is composed of a stationary-side fixed plate 911 and a female die core 912, the female die core 912 is locked with screws 913 in a female-die recess 914 in the stationary-side fixed plate 911; and the stationary-side fixed plate 911 is provided thereon with a material injection opening 915.

[0006] A die seat 92 at a movable side of the press casting die has a movable-side fixed plate 921 and a male die core 922 provided in opposition to the stationary-side fixed plate 911, the male die core 922 is locked with screws 923 in a male-die recess 924; and a guiding protrusion 925 is provided on the movable-side fixed plate 921 and in opposition to the material injection opening 915, the guiding protrusion 925 is provided on its lower bottom side with a guiding recess 925a in order that injected alloy can be injected therein and through a material injecting channel 922a of the male die core 922 into a die cavity between the male die core 922 and the female die core 912 to form a shaped article.

[0007] The die seat 92 at a movable side further is provided with a top plate set 926 which is limited to move between a pair of die-foot blocks 928; in releasing the die, the top plate set 926 gets close to the movable-side fixed plate 921, a plurality of pushing-out pins 927 on the movable-side fixed plate 921 will be extended through a plurality of through holes 929 of to the movable-side fixed plate 921 to push the shaped article out of the male die core 922 for collection.

[0008] In such a structure of the conventional press casting die, the average times of use before necessary changing of the male die core 922 and the female die core 912 is about 50˜80 thousands, otherwise, the surfaces of the die cavity between the die cores 922 and 912 when being used for about 80 thousand times will crack, and their outer edges will generate a phenomenon of having extreme serious rough edges; thus its material spilling area gets larger to affect the quality of the injected material, in this case, the entire die must be changed for a new one.

[0009] In the structure of the die seat 92 at the movable side, by virtue that the movable-side fixed plate 921 and the male die core 922 shall be drilled to have the through holes 929 and the drill holes, when the male die core 922 is to be changed, the movable-side fixed plate 921 must be changed too at the same time, this will increase the cost, the cost is awfully increased especially in the present days with material's prices going up to such high levels; and this further induces environmental problems, in view of these, improvement is wanted.

[0010] And more, in manufacturing some other article, with such a conventional structure of die, the whole set of die often needs to be changed. The reason of this is resided in that, when the female die core 912 and the male die core 922 respectively in the die seat 91 at a stationary side and in the die seat 92 at the movable side must be drilled to get a plurality of new screw holes to release the die; these new screw holes will overlap with the old screw holes, thus the die seat 92 at the movable side and the die seat 91 at a stationary side will be damaged and not suitable for use. In view of this, the conventional die is unable to change for a new male die core and a new female die core, and this is a problem that the present invention is to clear up.

[0011] In view of the above defect that the conventional press casting die is unable to change for a new male die core and a new female die core, the present invention provides a press casting die able to change its die cores for a new male die core and a new female die core, in which mainly a movable-side fixed plate of a die seat is provided behind a male-die recess with a plate receiving recess of a larger area, the plate receiving recess can be mounted therein with a changeable pressure bearing plate having thereon a plurality of holes for insertion of pushing-out pins, the pressure bearing plate is abutted against by a pair of die-foot blocks in its rear to thereby have sufficient bearing capability to assure its durability for a high pressure in material injection. Therefore, when life of use of the die cavity is exhausted, only the female die core, the male die core and the pressure bearing plate are necessarily changed, in this way, the cost of the die is largely reduced, and benefit of environmental conservation can be provided.

[0012] By virtue that in alloy injection, the range of pressure able to be born by the pressure bearing plate is about 50 kg/cm³˜300 kg/cm³, the two die-foot blocks are abutted against meeting areas between the pressure bearing plate and the two lateral edges of the plate receiving recess of the movable-side fixed plate, in order to brace the pressure bearing plate; meantime, a top plate set is provided at its four corners each with a pressure supporting post having therein a central screw for screw locking areas of the movable-side fixed plate near the lateral sides of the plate receiving recess, so that the end faces of the pressure supporting posts are also abutted against the meeting areas between the pressure bearing plate and the upper and lower sides of the plate receiving recess to provide sufficient supporting forces.

[0013] The present invention will be apparent in its structure and effect in use after reading the detailed description of the preferred embodiment thereof in reference to the accompanying drawings.

[0021] Referring to FIGS. 2-5, a press casting die provided in the present invention mainly is composed of a die seat 1 at a stationary side and a die seat 2 at a movable side thereof. The die seat 1 at the stationary side is fixed, while the die seat 2 at the movable side is mounted displaceably in order that the die seat 2 can be displaced to be close to or away from the die seat 1 to do the processes of die closing, injection and die releasing etc.

[0022] The die seat 1 at the stationary side of the present invention is provided mainly with a stationary-side fixed plate 11 having on its inner side a female-die recess 111 to receive a changeable female die core 12; four inside corners of the female-die recess 111 of the stationary-side fixed plate 11 are provided each with a screw 112 to lock a female die core 12 but to keep the function of changing. The stationary-side fixed plate 11 has thereon a material injection opening 113, and has on each of its four corners a guide-rod hole 114.

[0023] The die seat 2 at the movable side is composed of a movable-side fixed plate 21, a male die core 22, a pressure bearing plate 23, a top plate set 24 and a pair of die-foot blocks 25.

[0024] The movable-side fixed plate 21 is formed on its inner side a male-die recess 211 able to receive the changeable male die core 22, the male-die recess 211 has behind it a plate receiving recess 212 of a larger area, the plate receiving recess 212 can be mounted therein with the changeable pressure bearing plate 23 having thereon a plurality of holes 231 for insertion of pushing-out pins. The pressure bearing plate is provided at its four corners each with an outer screw 232 and an inner screw 233; the outer screws 232 are used to lock the pressure bearing plate 23 in the plate receiving recess 212 of the movable-side fixed plate 21, while the inner screws 233 are used to lock the male die core 22 (referring to FIG. 6). The movable-side fixed plate 21 is provided at its four corners each with a guiding hole 213. The upper edge of the male-die recess 211 of the movable-side fixed plate 21 is provided with a guiding protrusion 214 which is extended into the material injection opening 113 of the stationary-side fixed plate 11 when in material injecting; the guiding protrusion 214 is provided on its lower bottom side with a guiding recess 215 in order that injected material can be injected therein and through a material injecting channel 221 of the male die core 22 into a die cavity between the female and the male die cores 12, 22. The movable-side fixed plate 21 is provided at its four corners each with a fixed-plate guide rod 216, in closing the die, the fixed-plate guide rod 216 is extended into a corresponding guide-rod hole 114 of the stationary-side fixed plate 11.

[0025] The top plate set 24 is composed of an inner and an outer top plate 241, 242; its width is smaller and its height is larger respectively than those of the pressure bearing plate 23, and it is provided behind the pressure bearing plate 23; the outer top plate 242 is provided with a plurality of pushing-out pins 243 in corresponding with the holes 231 respectively. The top plate set 24 is further provided at its four corners each with a top-plate guiding post 244; when the top plate set 24 gets close to the movable-side fixed plate 21 to push out an article with the pushing-out pins 243, the top-plate guiding posts 244 will be extended into the guiding holes 213 respectively provided at the four corners of the movable-side fixed plate 21.

[0026] The top plate set 24 is provided in its rear with a pair of die-foot blocks 25 to provide supporting forces for the pressure bearing plate 23 when in injection, the die-foot blocks 25 are formed on their rear ends flanges 251 to prevent rearward moving of the top plate set 24. The die-foot blocks 25 are locked onto the movable-side fixed plate 21 with bolts 252. Referring to FIG. 6, the die-foot blocks 25 are abutted against meeting areas between the pressure bearing plate 23 and the two lateral edges of the plate receiving recess 212 of the movable-side fixed plate 21. In addition to this, the top plate set 24 is provided at its four corners each with a pressure supporting post 3 having therein a central screw 31 for abutting against the areas of the movable-side fixed plate 21 near the lateral sides of the plate receiving recess 212, so that the end faces of the pressure supporting posts 3 are also abutted against the meeting areas between the pressure bearing plate 23 and the upper and lower sides of the plate receiving recess 212 to provide sufficient supporting forces as shown in FIG. 7.

[0027] In the process of press casting, the die seat 2 at the movable side is displaced to get close to the die seat 1 at the stationary side, then alloy is injected into the material injection opening 113 of the stationary-side fixed plate 11 and through the guiding recess 215 of the movable-side fixed plate 21 to get into the die cavity between the female and the male die cores 12, 22 to form an article. After that, the die seat 2 at the movable side is displaced to get away from the die seat 1 at the stationary side to release the die; the article then gets through the pressure bearing plate 23 by the action of the pushing-out pins 243 pushed by the top plate set 24 (referring to FIG. 6 wherein the top plate set 24 moves upwards), the male die core 22 pushed out then is recollected.

[0028] One thing worth noticing, the pressure bearing plate 23 on the movable-side fixed plate 21 of the die seat 2 at the movable side in the present invention is detachable, this renders the male die core 22 on the movable-side fixed plate 21 at the movable side and the female die core 12 on the stationary-side fixed plate 11 both able to be detached for changing. Thereby, when the die cavity is exhausted in its life of use, only the female die core 12, the male die core 22 and the pressure bearing plate 23 are necessarily changed, in this way, the cost of the die is largely reduced, and benefit of environmental conservation can be provided.

[0029] Additionally, by the specific design of positions of the pressure supporting posts 3 and the die-foot blocks 25 in the rear of the movable-side fixed plate 21, the pressure bearing plate 23 has sufficient bearing capability to assure its durability for the pressure in material injection, and thereby stability and safety of the article can be preserved.

[0030] In conclusion, according to the description disclosed above, the press casting die having the changeable male die core, female die core of the present invention is patentable in the light of the above teachings.