JP4520579B2 - Molding equipment for casting - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a casting mold apparatus, and more particularly, to a casting mold apparatus including a mold that is excellent in durability and can be easily replaced.
[0002]
[Prior art]
As the casting mold apparatus, a fixed plate, a movable plate that can approach or separate from the fixed plate, at least one pair of sliding side plates that can approach or separate from both plates, and each of the plates are installed. A fixed plate side mold, a movable plate side mold, and at least one pair of sliding side plate molds can be exemplified. Then, by cooling and solidifying the molten metal filled in the cavities formed when these four molds are clamped together, a cast product corresponding to the shape of the surface forming the cavities of each mold is obtained. It is done. Each die is formed by sintering a powder of a material having excellent thermal shock resistance, such as a powder of molybdenum alloy, tungsten alloy, or SKD steel (JIS standard).
[0003]
When casting a cylinder head of an internal combustion engine using this type of casting mold apparatus, a stationary platen mold 1 shown in FIG. 5 is used. On the central axis along the longitudinal direction of the fixed platen mold 1, four combustion chamber molding cores 2a to 2d for forming combustion chambers of the cylinder head are disposed. The upper end surfaces of the combustion chamber molding cores 2a to 2d are gently bent surfaces, and an intake port molding core (not shown) or an exhaust port molding core (not shown) is engaged from the upper end surface. The engaging convex part 3 for projecting.
[0004]
That is, one end of the intake port molding core or the exhaust port molding core is engaged with the engagement convex portion 3 on the upper end surface of the combustion chamber molding cores 2a to 2d, and the other end portion is engaged. It is engaged with a recess for engagement (not shown) formed in a pair of sliding side panel molds (not shown) and fixed in position.
[0005]
Further, in the stationary platen mold 1, four gates 4a to 4d for filling the molten metal are positioned obliquely above and below the adjacent combustion chamber forming cores 2a, 2b or 2c, 2d. It is formed as follows. Stokes (not shown) are inserted into the gates 4a to 4d, and the molten metal poured from the tip of the stalk is filled into the cavity through the gates 4a to 4d. In FIG. 5, reference numeral 5 denotes a fixed platen.
[0006]
[Problems to be solved by the invention]
By the way, the molten metal is a molten metal, and inevitably has a high temperature. Therefore, when the molten metal is filled in the cavity, in the fixed platen mold 1, the temperature in the vicinity of the gates 4a to 4d is rapidly increased and thermally expanded. On the other hand, the rate of temperature rise at a location that is significantly separated from the gates 4a to 4d in the fixed platen mold 1 is slow, and therefore the amount of thermal expansion is small. For this reason, thermal stress is generated in the fixed platen mold 1.
[0007]
Usually, the casting operation of the cylinder head is continuously performed. Therefore, the stationary platen mold 1 is repeatedly expanded and contracted by heat. However, when the expansion and contraction due to heat is repeated in this way, a portion where the strength of the stationary platen mold 1 is not good, for example, a thin portion (for example, between adjacent combustion chamber molding cores 2a and 2b) , The possibility that cracks will occur in the mesh portion in FIG.
[0008]
Of course, when the casting operation is performed in a state where the fixed platen side mold 1 is cracked, a cylinder head having a desired shape cannot be obtained. Therefore, the fixed platen side die 1 is replaced with a spare part. Is required. In this case, since the casting mold apparatus cannot be used during the replacement work period, the efficiency of the casting work is reduced. Moreover, since the spare part of the fixed plate | board side metal mold | die 1 with a large shape is required, it raises the casting cost.
[0009]
That is, the casting mold apparatus according to the prior art has a high possibility that cracks will occur in the stationary platen mold 1, and therefore, there is a problem that the casting work efficiency is lowered and the casting cost is increased. It has become apparent.
[0010]
The present invention has been made to solve the above-described problems, and provides a casting mold apparatus that includes a mold having excellent durability and can be easily replaced, thereby reducing casting costs. For the purpose.
[0011]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a fixed platen side mold and a movable platen side mold for casting a cylinder head of an internal combustion engine having a combustion chamber,
A combustion chamber molding core installed in the stationary platen mold to form the combustion chamber;
Said to fill the molten metal in the cavity formed by the stationary platen side mold and the movable platen side mold, the sprue that the combustion chamber molding core is formed on the stationary platen side mold installed,
With
A thin wall portion of the stationary platen mold in which the combustion chamber molding core is installed is divided.
[0012]
When the cavity is filled with the molten metal, the divided mold has a low thermal conductivity, so the thermal stress generated in the mold is extremely small. In addition, since the thin portion is divided in advance, the occurrence of cracks in the thin portion is avoided, and eventually the durability of the mold is improved, so that the casting efficiency is improved and the casting cost is reduced.
[0013]
Moreover, since it is sufficient to produce a small-shaped piece as a spare mold, the cost required for mold production can be reduced, and eventually the casting cost can be reduced. Moreover, since the piece has a small shape, the damaged piece can be easily and inexpensively replaced.
[0014]
As a thin part of a metal mold | die, between the installation location of the said core for combustion chamber shaping | molding, or between the installation location of the said core for combustion chamber shaping | molding, and a gate can be mentioned, for example.
[0015]
In this case the split the fixed platen side mold, it is preferable to further divide over the outer wall of the stationary platen side mold from said pouring gate.
[0016]
Further, the divided the stationary platen side mold, the installation location of the combustion chamber molding core at both ends is preferably divided over the outer wall of the stationary platen side mold.
[0017]
In any case, since the mold is divided more finely, the above effect becomes more remarkable.
[0018]
Further, the divided the stationary platen side mold, Rukoto provided on the fixed platen side mold in a state of being accommodated in the frame is preferable. This is because it is possible to avoid the individual pieces from being dispersed.
[0019]
Then, divided the stationary platen side mold What happened, and it is preferable that the divided the stationary platen side mold and the frame are spaced apart from each other. Even if the divided stationary platen mold is thermally expanded, the thermal expansion portion only narrows the gap between the molds or the gap between the mold and the frame, and it is possible to suppress the thermal expansion of the molds. Absent. Therefore, the thermal stress generated in the mold is further reduced.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of a casting mold apparatus according to the present invention will now be described in detail with reference to the accompanying drawings. Components corresponding to those shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0021]
First, FIG. 1 shows a cylinder head cast by the casting mold apparatus according to the present embodiment. Four combustion chambers 14 a to 14 d are formed on the cylinder block abutting surface 12 of the cylinder head 10, while four ports 18 a to 18 d used for intake and exhaust are formed on one side 16 of the cylinder head 10. Is formed. These ports 18a to 18d are bifurcated inside the cylinder head 10 and communicate with ports 20a and 20b formed in the combustion chambers 14a to 14d. Similarly, four ports (not shown) are also formed on the other side (not shown) facing the one side surface 16, and each port is bifurcated inside the cylinder head 10 and formed in the combustion chambers 14 a to 14 d. The ports 22a and 22b communicate with each other.
[0022]
In FIG. 1, reference numeral 24 indicates a protrusion formed by cooling and solidifying the molten metal remaining in the gates 4a to 4d.
[0023]
FIG. 2 shows a longitudinal sectional view of a main part of a casting mold apparatus according to the present embodiment for casting such a cylinder head 10. The casting mold apparatus 30 includes a fixed plate 31, a movable plate 32 that can approach or separate from the fixed plate 31 by an actuator mechanism (not shown), and a pair of slides that can approach or separate from both plates 31 and 32. Each of the boards 31, 32, 33a, 33b includes a fixed board side mold (hereinafter referred to as a lower mold) 34, a movable panel side mold (hereinafter referred to as an upper mold) 36, Sliding side panel side molds (hereinafter referred to as side molds) 38a and 38b are respectively installed. The lower mold 34, the upper mold 36 and the pair of side molds 38a and 38b approach each other and are clamped to form a cavity 40.
[0024]
A plan view of the lower die 34 is shown in FIG. On the central axis of the lower mold 34, four combustion chamber forming cores 2a to 2d for forming the combustion chambers 14a to 14d of the cylinder head 10 are disposed. From the upper end surfaces of the respective combustion chamber molding cores 2a to 2d, there are engaging convex portions 3 engaged with one end portions of the intake port molding core 42 or the exhaust port molding core 44 shown in FIG. It protrudes.
[0025]
The lower die 34 is divided into eleven lower die pieces 48a to 48k by dividing lines 46a to 46t starting from the installation locations of the respective combustion chamber molding cores 2a to 2d. That is, for example, the three parting lines 46a to 46c starting from the installation location of the combustion chamber molding core 2a all extend in the diameter direction of the combustion chamber molding core 2a. Of these, the dividing line 46a is formed along the central axis of the lower mold 34, and the dividing line 46b and the dividing line 46c are formed at positions symmetrical with respect to the central axis. The two dividing lines 46d and 46e, which are the starting point of the installation location of the combustion chamber forming core 2b adjacent to the combustion chamber forming core 2a and are symmetrical with respect to the dividing lines 46b and 46c, are divided. The lines 46b and 46c intersect with each other, and extend from the intersections to the outer wall of the lower mold 34 as integral dividing lines 46f and 46g. The same applies to the remaining dividing lines 46h to 46s, and the dividing line 46t is formed on the central axis similarly to the dividing line 46a.
[0026]
In the lower mold 34, the gate 4a is formed at the intersection of the dividing lines 46b, 46d and 46f. Similarly, the gate 4b is formed at the intersection of the dividing lines 46c, 46e and 46g, the gate 4c is formed at the intersection of the dividing lines 46n, 46p and 46r, and the gate 4d is formed at the intersection of the dividing lines 46o, 46q and 46s.
[0027]
That is, in the lower die 34, between the combustion chamber molding cores 2a, 2b and the gates 4a, 4b, between the combustion chamber molding cores 2c, 2d and the gates 4c, 4d, between the combustion chamber molding cores 2b, It is divided from a thin portion such as between 2c.
[0028]
The lower die 34 divided into eleven lower die pieces 48a to 48k by the dividing lines 46a to 46t is accommodated in a recess 52 provided in the stationary platen 31 while being accommodated in the mold frame 50. By doing so, they are positioned and fixed to the stationary platen 31 without being separated from each other (see FIG. 2).
[0029]
Of course, as shown in an enlarged view in FIG. 4, the mold frame 50 is provided with each lower mold piece 48a so as not to hinder the thermal expansion of the lower mold pieces 48a to 48k when the cavity is filled with molten metal. It is formed with a dimension having a slight gap 54 between ˜48k. Similarly, the lower mold pieces 48a to 48k are also formed with dimensions having a slight gap 54 between the lower mold pieces adjacent to each other.
[0030]
The fixing plate 31, the mold frame 50, and the lower mold 34 are formed with through holes 56, 58, and 59, respectively, which are in communication with each other. And the front-end | tip part of the stalk 60 which passed these through-holes 56, 58, 59 connected is inserted in the gates 4a-4d (refer FIG. 2).
[0031]
Hereinafter, the side molds 38a and 38b and the upper mold 36 will be described with reference to FIG.
[0032]
The side molds 38a and 38b are respectively installed on the sliding side boards 33a and 33b as described above. Concave portions 61a and 61b are formed in the both-side molds 38a and 38b, respectively, and the other end portions of the intake port molding core 42 or the exhaust port molding core 44 are fitted into the concave portions 61a and 61b. Yes. And the side part of the upper mold | type 36 is fitted above these side type | molds 38a and 38b.
[0033]
On the other hand, the upper mold 36 is installed on the movable platen 32. A plurality of valve guide cast pins 64, 64 are inserted into the through holes 62, 62, 63, 63 formed in the upper die 36 and the movable platen 32 so as to be inclined at a predetermined angle, so that the valve can be displaced. The tip portions of the guide core pins 64, 64 are in contact with the intake port molding core 42 and the exhaust port molding core 44.
[0034]
Further, through holes 66 and 68 are formed in the upper mold 36 and the movable platen 32 so as to communicate with each other, and the cast cylinder head 10 is detached from the upper mold 36 through the communicated through holes 66 and 68. Displaceable ejector pins 70 are inserted.
[0035]
In FIG. 2, reference numeral 72 denotes a water jacket portion molding core for molding the water jacket portion.
[0036]
The casting mold apparatus 30 according to the present embodiment is basically configured as described above. Next, the function and effect will be described.
[0037]
First, after the combustion chamber molding cores 2a to 2d are installed in the lower die 34, the intake port molding core 42 or the exhaust port molding middle is formed on the engaging projections 3 of the combustion chamber molding cores 2a to 2d. One end of the child 44 is engaged.
[0038]
Next, the lower mold 34 and the upper mold 36 of the casting mold apparatus 30 are brought close to each other. Thereafter, the pair of sliding side plates 33a and 33b are brought close to the fixed platen 31 and the movable platen 32 and clamped by the side molds 38a and 38b. As a result, the cavity 40 is formed, and the other end portions of the intake port molding core 42 and the exhaust port molding core 44 are fitted into the recesses 61a and 61b of the side molds 38a and 38b.
[0039]
In this state, the valve guide core pin 64 is displaced toward the interior of the cavity 40, and its tip is brought into contact with the intake port molding core 42 and the exhaust port molding core 44.
[0040]
Next, the molten metal is filled into the cavity 40 through the stalk 60 and the gates 4a to 4d.
[0041]
At that time, the temperature of the lower mold 34 in the vicinity of the gates 4a to 4d of the lower mold 34 rapidly increases. However, as described above, the lower mold 34 is divided into eleven lower mold pieces 48a to 48k, and the lower mold pieces adjacent to each other are separated from each other. Therefore, the heat conduction speed of the entire lower mold 34 is smaller than that of the fixed platen mold 1 according to the above-described conventional technique. For this reason, since the amount of thermal expansion of each lower mold piece 48a-48k becomes small, the thermal stress which generate | occur | produces in the lower mold | type 34 becomes remarkably small.
[0042]
Moreover, the thermal expansion portions of the mold frame 50 and the lower mold pieces 48a to 48k are separated from the gap 54 between the mold frame 50 and the lower mold pieces 48a to 48k and the adjacent lower mold pieces as shown by phantom lines in FIG. The gap 54 is only narrowed, and they are not pressed against each other. Eventually, the thermal expansion of the lower mold pieces 48a to 48k is not suppressed, so that the thermal stress generated in the lower mold 34 is further reduced.
[0043]
Further, as can be understood from FIG. 3, the installation locations of the combustion chamber forming cores 2a and 2b adjacent to each other are divided by dividing lines 46f and 46g, and the combustion chamber forming cores 2a and 2b are divided. Are separated by dividing lines 46b to 46e. Similarly, the installation locations of the combustion chamber forming cores 2b and 2c are divided by dividing lines 46h to 46m, respectively, and the installation locations of the combustion chamber forming cores 2c and 2d are divided by dividing lines 46r and 46s. The space between the installation locations of the combustion chamber forming cores 2c, 2d and the gates 4c, 4d are divided by dividing lines 46n to 46q, respectively. That is, since the thin part of the lower mold 34 is divided in advance, the occurrence of cracks in the lower mold 34 is avoided. For this reason, durability of the lower mold | type 34 improves and lifetime is achieved. Eventually, since the replacement frequency of the lower die 34 is reduced, the casting efficiency is improved, and thus the casting cost is reduced.
[0044]
Further, in this casting mold apparatus 30, when any of the lower mold pieces 48a to 48k is damaged, only the damaged lower mold piece may be replaced. That is, there is no need to replace other lower mold pieces that are not damaged. Therefore, since it is only necessary to produce a small-shaped lower mold piece as a spare product, the cost required for mold production is reduced, and this also ultimately reduces the casting cost. In addition, in this case, since the lower mold piece has a small shape, it can be easily replaced.
[0045]
Then, the cylinder head 10 shown in FIG. 1 is obtained by cooling and solidifying the molten metal.
[0046]
The pair of sliding side plates 33a and 33b and the movable platen 32 are separated from the fixed platen 31 by energizing an actuator mechanism (not shown), and then the ejector pin 70 is directed to the upper die 36. Then, the cylinder head 10 is detached from the upper mold 36 and can be taken out.
[0047]
In the above-described embodiment, the combustion chamber molding cores 2a to 2d are installed in the lower mold (fixed platen side mold) 34, but are installed in the upper mold (movable platen side mold) 36. You may do it.
[0048]
Further, a dividing line is further provided along the central axis in the longitudinal direction of the lower die 34 between the combustion chamber forming cores 2a, 2b, 2b, 2c and 2c, 2d. ˜48k may be divided into two.
[0049]
【The invention's effect】
As described above, according to the casting mold apparatus of the present invention, the stationary chamber side mold on which the combustion chamber molding core is installed and the gate is formed is adjacent to the combustion chamber molding core. It is divided from thin portions such as between the combustion chamber molding core and the gate. For this reason, when the cavity is filled with the molten metal, the heat conduction speed in the divided molds becomes slow, and as a result, the thermal stress generated in the molds is remarkably reduced. And since the thin part is divided | segmented previously, it is avoided that a crack generate | occur | produces in this thin part. Therefore, the effect that the durability of the mold is improved is achieved.
[0050]
Further, when the divided molds are damaged, only the damaged pieces need be replaced. That is, since it is sufficient to produce a small-shaped piece as the spare mold, the cost required for mold production can be reduced, and eventually the casting cost can be reduced. In addition, the damaged piece can be easily replaced.
[0051]
Further, since the divided molds and the divided molds and the frame for housing them are separated from each other, the thermal stress generated in the molds can be further reduced.
[Brief description of the drawings]
FIG. 1 is a schematic overall configuration diagram of a cylinder block manufactured by a casting mold apparatus according to the present embodiment.
FIG. 2 is a longitudinal sectional view of a main part of a casting mold apparatus according to the present embodiment.
3 is a plan view of a lower mold (fixed platen side mold) provided in the casting mold apparatus of FIG. 2. FIG.
4 is an enlarged explanatory view of a main part of FIG. 3;
FIG. 5 is a plan view of a stationary platen side mold provided in a casting mold apparatus according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 34 ... Fixed plate | board side metal mold | die (lower mold) 2a-2d ... Core 4a-4d for combustion chamber shaping | molding ... Cup 12 ... Cylinder head 30 ... Mold apparatus for casting 36 ... Movable board side metal mold | die (upper mold | type)
38a, 38b ... Sliding side panel side mold (side mold) 40 ... Cavity 46a-46t ... Partition line 48a-48k ... Lower mold piece 50 ... Mold frame 54 ... Gap

Claims (6)

A stationary platen side mold and a movable platen side mold for casting a cylinder head of an internal combustion engine having a combustion chamber;
A combustion chamber molding core installed in the stationary platen mold to form the combustion chamber;
Said to fill the molten metal in the cavity formed by the stationary platen side mold and the movable platen side mold, the sprue that the combustion chamber molding core is formed on the stationary platen side mold installed,
With
A casting mold apparatus, wherein a thin portion of the stationary platen mold in which the combustion chamber molding core is installed is divided.   2. The casting mold apparatus according to claim 1, wherein the thin portion is between the installation locations of the combustion chamber molding core or between the installation location of the combustion chamber molding core and a gate. 3. A casting mold apparatus characterized by the above. 3. The casting mold apparatus according to claim 2, wherein the divided fixed plate side mold is further divided from the gate to the outer wall portion of the fixed plate side mold. apparatus. 4. The casting mold apparatus according to claim 1, wherein the fixed mold on the fixed platen side is arranged so that the outer wall of the mold on the fixed platen side extends from the installation locations of the combustion chamber forming cores at both ends. A mold apparatus for casting, which is further divided into parts. 5. The casting mold apparatus according to claim 1, wherein the divided stationary platen side mold is provided on the stationary platen in a state of being accommodated in a frame. Molding equipment for casting. In casting mold system according to claim 1, divided the stationary platen side mold What happened, and a divided the stationary platen side mold and the frame separated from each other A mold apparatus for casting, characterized in that

Images