Casting mold for moldings

A casting mold which enables an article to be molded by replacing only a specification-variable mold component for molding a section of the article when the specification of only that particular section has been modified, thus permitting reduced manufacturing cost of the molding. The casting mold is used for casting a rear bracket 85 a mounting leg 10 which is subject to changes in specification and a component housing 9 which is combined with the mounting leg into one piece. It is equipped with a main body mold 40 for molding the component housing and a specification-variable mold 41 which is detachably connected to the main body mold, which can be replaced according to specifications, and which molds the mounting leg.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a casting mold (mold die for casting a 
bracket of an alternating-current generator to be mounted on a vehicle or 
the like. 
2. Description of the Related Art 
FIG. 9 is a side view showing a related vehicular alternating-current 
generator which is mounted on an engine. The vehicular alternating-current 
generator 1 is fixed to a stay 2 of an engine main body by using a bolt 3 
and a nut 4. A casing 5 of the vehicular alternating-current generator 1 
is constituted by a bowl-shaped rear bracket 6, which incorporates 
component parts and which is shown at left in the drawing, and a 
bowl-shape front bracket 8 which clamps a stator 7 in cooperation with the 
rear bracket 6 and which is shown at right in the drawing. Included in the 
casing 5 is a rotor (not shown) which is rotatably supported via a bearing 
(not shown). 
FIG. 10A is a top plan view of the rear bracket 6 shown in FIG. 9 and FIG. 
10B is a sectional view taken on line X--X shown in FIG. 10A. The rear 
bracket 6 is comprised of a component housing 9 which is shaped roughly 
like a bowl, and a mounting leg 10 which is attached to the stay 2. The 
component housing 9 has cooling windows 11 for cooling the rotor, etc. 
(not shown) in the casing 5 and tapped holes 12 for bolts 13 for 
connecting the rear bracket 6 and the front bracket 8, etc. Formed on the 
distal end of the mounting leg 10, which is v-shaped to minimize the 
weight thereof, is a mounting hole 14 in which the bolt 3 is inserted. The 
mounting hole 14 is positioned not too far from a rotary shaft (not shown) 
of the rotor so as to prevent the alternating-current generator 1, the 
center of gravity of which is positioned high, from becoming unstable when 
the alternating-current generator 1 is secured to the stay 2 of the main 
body of the engine. 
FIG. 11A is a top plan view of the front bracket 8 shown in FIG. 9 and FIG. 
11B is a sectional view taken on line XI--XI shown in FIG. 11A. The front 
bracket 8 is composed of: the component housing 9 which is shaped like a 
bowl shallower than that of the rear bracket 6 and which has cooling 
windows 18; a mounting leg 16 attached to the stay 2; and a mounting 
section 17 positioned on the opposite side to the mounting leg 16. The 
mounting leg 16 has a mounting hole 19 in which the bolt 3 is inserted. 
The mounting section 17 is secured to a base 20 by a bolt 22 which is 
threaded through a tapped hole 21 as illustrated in FIG. 9. 
The rear bracket 6 and the front bracket 8 are produced by the following 
main steps: pouring molten aluminum into a mold which has been formed by 
electric discharge machining or the like; forming the cooling windows 11, 
18, etc.; removing it from the mold; processing the end surfaces of 
the-molded article by cutting work; and cutting threads. 
FIG. 12 is a sectional view of a mold for the rear bracket 6. A cope 30a 
which is shown at left in the drawing and a drag 30b which is shown at 
right in the drawing are in close contact, facing each other. In the 
drawing, the molten aluminum is poured from above and cooled, then the 
drag 30b is separated from the cope 30a to take out the molded article, 
namely, the rear bracket. The molded rear bracket is subjected to cutting 
work, tapping, etc. to be completed as the rear bracket 6. 
The component housing 9 of the rear bracket 6 is deeper than that of the 
front bracket 8; therefore, the volume of the casting mold for the rear 
bracket 6 is larger. The mold is tapered to a certain extent in the mold 
separating direction so as to allow the bracket material to be separated 
from the mold. 
The vehicular alternating-current generator 1 generates heat when 
generating power. Hence, it is necessary to cool the stator, rotor, etc. 
by air coming through the cooling windows 11 and 18. For this reason, the 
brackets 6 and 8 are provided with as many cooling windows 11 and 18 as 
possible without compromising the overall physical strength thereof. 
In the conventional vehicular alternating-current generator 1, when the 
specifications of the mounting legs 10 and 16 are changed (e.g. changing a 
diameter C of the mounting hole 14 provided in parallel to the rotary 
shaft, or changing a distance D between the center of the mounting hole 14 
and the rotational center of the rotor, or changing a pitch E width of 
stay! when the rear bracket 6 and the front bracket 8 are combined, it is 
necessary to prepare a new casting mold or to machine the whole cope 30 a 
and drag 30 b even if the shape of the component housing 9 remains utterly 
unchanged. This has required extra time and labor, leading to higher 
manufacturing cost. 
There has been another problem: because of the molding requirements, for 
example, the cooling windows cannot be formed directly by molding in a 
shaded area "a" of the component housing 9 in the shade of the mounting 
leg 10 as illustrated in FIG. 10B; therefore, the shaded area "a" must be 
subjected to cutting work after casting, which is an extra machining step. 
SUMMARY OF THE INVENTION 
The present invention has been made with a view toward solving the problems 
described above and it is an object of the present invention to provide a 
casting mold for moldings which enables an article with modified 
specifications to be molded by changing a specification-variable mold 
portion designed for molding the modified portion of the article, thereby 
permitting reduced manufacturing cost of moldings. 
It is another object of the present invention to provide a casting mold for 
moldings which enables holes to be placed in the article being formed 
during the molding process. 
To these ends, according to the present invention, there is provided a 
casting mold for moldings which is equipped with a main body mold for 
molding a main body, and a specification-variable mold which is detachably 
connected to the main body mold, which can be replaced according to 
specifications and which molds a modified portion. 
The modified portion refers to the mounting leg of a bracket to be 
installed on an intended object; the main body refers to the component 
housing of the bracket. 
Further, the main body mold is constituted by a first main body mold 
counterpart and a second main body mold counterpart which is opposed to 
and in close contact with the first main body mold counterpart. The 
specification-variable mold is constituted by a first 
specification-variable mold counterpart and a second 
specification-variable mold counterpart which is opposed to and in close 
contact with the first specification-variable mold counterpart. 
The second specification-variable mold counterpart is provided with a 
projection for molding holes. 
The moldings are the brackets for vehicular alternating-current generators.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
First Embodiment! 
FIG. 1 is a sectional view which illustrates a casting mold for a rear 
bracket of a vehicular alternating-current generator showing an embodiment 
of the present invention. Parts identical or equivalent to those shown in 
FIG. 9 through FIG. 12 will be assigned the same reference numerals, and 
the description thereof will be omitted. 
The casting mold for the rear bracket is composed of a main body mold 40 
for molding the component housing 9 which is the bowl-shaped main body and 
a specification-variable mold 41 for molding the mounting leg 10 which can 
be varied, i.e., its specifications can be modified. The main body 40 is 
constructed by a first main body mold counterpart 40a and a second main 
body mold counterpart 40b which is opposed to and in close contact with 
the first main body mold 40a. A specification-variable mold 41 is 
constituted by a first specification-variable mold counterpart 41a and a 
second specification-variable mold counterpart 41b which is opposed to and 
in close contact with the first specification-variable mold counterpart 
41a. 
The casting mold described above as related art is composed of two blocks, 
namely, the cope 30 a and the drag 30 b, while this embodiment is 
comprised of four blocks, namely, the first main body mold counterpart 
40a, the second main body mold counterpart 40b, the first 
specification-variable mold counterpart 41a, and the second 
specification-variable mold counterpart 41b. 
Casting by combining the separate molds, i.e. the first 
specification-variable mold counterpart 41a and the second 
specification-variable mold counterpart 41b, provides the following 
advantage: if only the mounting leg 10 needs to be modified according to a 
change in specification, then only the first specification-variable mold 
counterpart 41a and the second specification-variable mold counterpart 41b 
need to be removed and modified, thus reducing the required time and labor 
for the modification. 
Moreover, when the specification of only the mounting section of the engine 
is changed, the conventional casting mold requires both the cope 30 a and 
the drag 30 b be newly created, whereas this embodiment requires only the 
small parts, i.e. the first specification-variable mold counterpart 41a 
and the second specification-variable mold counterpart 41b, to be newly 
created. In other words, when the shape of the component housing 9 of the 
rear bracket 6 remains unchanged, only the cost for creating the first 
specification-variable mold counterpart 41a and the second 
specification-variable mold counterpart 41b will be added, resulting in 
lower manufacturing cost of the rear bracket 6. 
Likewise, the rear bracket 6 in which only the thickness of the mounting 
leg 10 and the angle of the V shape thereof are different can be 
manufactured by using the same first main body mold counterpart 40a and 
the second main body mold counterpart 40b, thus enabling significant 
reduction in the manufacturing cost of the rear bracket 6. 
The mounting leg 10 is required to have an appropriate thickness H and 
shape to achieve lighter weight and assure adequate strength at the same 
time. Such thickness H and shape can be obtained by modifying only the 
first specification-variable mold counterpart 41a and the second 
specification-variable mold counterpart 41b. 
Second Embodiment! 
FIG. 2 is a sectional view of the casting mold for the rear bracket 6 of 
the vehicular alternating-current generator illustrative of another 
embodiment of the present invention; FIG. 3A is a top plan view of a rear 
bracket which has been molded using the casting mold shown in FIG. 2 and 
which has been machined thereafter; and FIG. 3B is a sectional view taken 
on line III--III shown in FIG. 3A. 
In the casting mold according to this embodiment, the second 
specification-variable mold counterpart 41b has a projection 42 for 
molding the cooling windows 11 which are openings. 
The second specification-variable mold counterpart 41b can be separated 
from the second main body mold counterpart 40b in the direction of arrow 
"b"; therefore, by forming the projection 42 on the second 
specification-variable mold counterpart 41b, the cooling windows 11 shown 
in FIG. 4 can be formed by molding even in the shaded area "a" of the 
component housing 9 which is in the shade of the mounting leg 10. 
Third Embodiment! 
FIG. 5 is a sectional view showing the casting mold for the rear bracket of 
the vehicular alternating-current generator illustrative of still another 
embodiment of the present invention; FIG. 6A is a top plan view showing 
the rear bracket which has been molded using the casting mold shown in 
FIG. 5 and machined thereafter; and FIG. 6B is a sectional view taken on 
line VI--VI shown in FIG. 6A. 
The third embodiment is different from the second embodiment in that the 
distance D between the center of the mounting hole 14 and the center of 
the rotary shaft is larger. Fourth Embodiment! 
FIG. 7 is a sectional view showing the casting mold for the rear bracket of 
the vehicular alternating-current generator illustrative of yet another 
embodiment of the present invention; FIG. 8A is a top plan view showing 
the rear bracket which has been molded using the casting mold shown in 
FIG. 7 and machined thereafter; and FIG. 8B is a sectional view taken on 
line VIII--VIII shown in FIG. 8A. 
The fourth embodiment is different from the second embodiment in that the 
thickness H of the mounting leg 10 is greater. 
All the embodiments described above use, as the molded article, the rear 
bracket 6 of the vehicular alternating-current generator; however, the 
casting molds described in the embodiments can also be used for molding 
the front bracket 8. Further, the casting mold in accordance with the 
present invention can also be used for molding, for example, the bracket 
of a starter and the housing of a distributor. 
Thus, the casting mold for moldings in accordance with the present 
invention makes it possible to cast moldings of different specifications 
by changing only the specification-variable mold counterparts 
corresponding to the modified portions, thus permitting reductions in the 
cost involved in specification changes in moldings with consequent 
reductions in the manufacturing cost of moldings. 
In addition, the second specification-variable mold counterpart provided 
with the projection for molding holes in moldings makes it possible to 
easily form by molding the cooling windows on, for example, the component 
housing of the bracket of a vehicular alternating-current generator, which 
has not been achievable by conventional casting molds.