JP2000312962A - Device and method for casting cylinder head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high quality casting article by giving directivity suitable for cooling the molten metal after casting using a shape of a cylinder head. SOLUTION: In this casting method, molten metal is poured/charged in a casting cavity formed between an upper die DU and a lower die DL from a gate Di installed to the lower die, and is solidified so as to cast a cylinder head of an engine. In this case, plural protrusion parts for forming holes (a plug hole, a bolt hole) are arranged to the upper die, and a cooling means is installed to each protrusion part respectively. The cooling means are set in a manner that the means at plug hole forming protrusion parts on the inner side comparatively close to the die center have larger cooling ability than those at bolt hole forming protrusion parts on the outer side comparatively close to the die periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a casting apparatus and a casting method for casting a cylinder head of an engine.

[0002]

2. Description of the Related Art As is well known, a cylinder head of an engine of an automobile or the like has a complicated structure such as a supply / exhaust port to a cylinder portion, a passage of engine cooling water (water jacket), and a passage of engine oil (oil jacket). In addition to passages of various shapes, plug holes for ignition plugs according to the number of cylinders and many bolt holes for assembly to the cylinder body are provided, so machining such as cutting is applied as a whole. It has a rather complicated shape that is difficult to obtain, and is usually obtained as a casting using aluminum alloy or the like as a material.

[0003] As a casting method for casting such a cylinder head, the surface of a molten metal in a crucible is pressurized by pressurized air or the like to push up the molten metal in the stalk, and the pushed molten metal is supplied into a mold cavity. A so-called low-pressure casting method for casting is known (for example, see JP-A-1-53755).
Reference). According to this low-pressure casting method, the molten metal is pressurized with pressurized air or the like, so that a stable and high-quality cast product can be obtained. Various advantages can be obtained, for example, it can be improved.

[0004]

When a gas such as gas or air is present in a casting cavity filled with a molten metal, the "casting cavity" caused by such a gas remaining in a casting product. In order to prevent the occurrence of casting defects, it is known that it is effective to provide directivity to cooling of the molten metal after the casting step so that the molten metal solidifies from a portion as far as possible from the gate. By cooling and solidifying the molten metal under such directivity, the gas present in the casting cavity is gradually pushed to the gate side, and finally solidifies in a state where it is accumulated in this gate section. It is possible to do. Since the sprue portion is cut and removed as an unnecessary portion after the completion of casting, the cast product itself is less likely to have gas remaining, and the occurrence of casting defects can be effectively suppressed. .

[0005] In particular, in the above-mentioned low-pressure casting method, a gate is often provided on the lower die side of the upper and lower dies, and in this case, the gas present in the cavity filled with the molten metal is far from the gate. Since it is common to rise to the mold side, it is more important to cool the molten metal with directivity such that the molten metal is gradually cooled from the upper mold side as far as possible from the gate.

In addition, when the molten metal in the casting cavity is cooled and solidified, the outside near the mold surface is usually easier to cool than the center side of the casting cavity due to natural heat radiation to the outside of the casting cavity. Gas tends to remain on the center side of the casting cavity. For this reason, it is preferable to cool the molten metal having directivity such that the molten metal is gradually cooled from the central portion as much as possible from the central portion and the outer portion of the casting cavity. That is, in general, in the casting process, for the purpose of improving the productivity and the like, when solidifying the molten metal after casting, a cooling step is provided to promote the solidification of the molten metal. In the process, it is required not only to increase the solidification rate but also to perform the cooling with the directivity as described above.

In view of the above, according to the present invention, when casting a cylinder head of an engine, the shape of the cylinder head is used to give appropriate directivity to cooling of the molten metal after casting, thereby obtaining a high quality cast product. It is done for the purpose of doing so.

[0008]

For this reason, a cylinder head casting apparatus according to the invention of claim 1 of the present application (hereinafter referred to as the first invention of the present application) is provided with a pair of detachably provided cylinder heads. The upper mold and the lower mold are provided, and the molten metal is injected into the casting cavity formed between both molds from the gate provided in the lower mold.
A casting device for filling and solidifying the molten metal to cast an engine cylinder head. These cooling means are characterized in that the cooling capacity of the inner protrusion relatively close to the center of the mold is set to be larger than that of the outer protrusion relatively close to the periphery of the mold. .

The invention according to claim 2 of the present application (hereinafter referred to as “the invention”)
This is referred to as the second invention of the present application. In the first aspect, the cooling medium of the cooling means provided on the inner projection is liquid, and the cooling medium of the cooling means provided on the outer projection is gas. It is.

[0010] Further, the invention according to claim 3 of the present application (hereinafter referred to as the invention)
This is referred to as the third invention of the present application. The second invention is characterized in that, in the second invention, after the cooling operation of the cooling means provided on the inner protrusion is stopped, an elimination means for eliminating the cooling medium remaining in the protrusion is provided. is there.

Further, the invention according to claim 4 of the present application (hereinafter referred to as a fourth invention of the present application) is characterized in that
A third aspect of the invention is characterized in that the projecting portion corresponds to at least a plug hole relatively close to the center of the cylinder head and a bolt hole relatively close to the periphery of the cylinder head. is there.

Still further, the invention of claim 5 of the present application (hereinafter referred to as “the invention”)
This is referred to as the fifth invention of the present application. The cylinder head casting apparatus according to the present invention comprises a pair of upper and lower dies and a side wall provided so as to be able to come and go, and the lower die is provided in a casting cavity formed by the two dies and the side wall. A casting apparatus in which a molten metal is injected and filled from a gate to solidify the molten metal to cast a cylinder head of an engine, wherein heat is applied to at least one of the upper mold and the lower mold in a direction other than a predetermined direction. A spot cooling means set so as to suppress propagation is provided.

Further, the invention according to claim 6 of the present application (hereinafter referred to as a sixth invention of the present application) is the invention according to the fifth invention, wherein the spot cooling means includes a cooling medium in a cylindrical member. The tubular member is provided with a passage, and one end surface of the tubular member faces the inside of the casting cavity, and an outer peripheral portion is fitted in a mounting hole provided in the mold.

Further, in the invention according to claim 7 of the present application (hereinafter referred to as a seventh invention of the present application), in the sixth invention, a part of the side wall is formed by a sand wall,
The spot cooling means is provided near the sand wall.

Further, the invention according to claim 8 of the present application (hereinafter referred to as an eighth invention of the present application) is the invention according to any one of the fifth to seventh inventions, wherein Is provided with a molten metal supply unit for supplying molten metal injected into the casting cavity through the gate, a predetermined space is provided between the molten metal supply unit and the lower mold, and the spot is provided in the space. A cooling medium path for cooling means is arranged,
A communication path for communicating the molten metal supply section and the gate is formed.

Still further, the invention of claim 9 of the present application (hereinafter referred to as “the invention”)
This is referred to as the ninth invention of the present application. The cylinder head casting apparatus according to the present invention comprises a pair of upper and lower dies and a side wall provided so as to be able to come and go, and the lower die is provided in a casting cavity formed by the two dies and the side wall. What is claimed is: 1. A casting apparatus in which a cylinder head of an engine is cast by injecting and filling a molten metal from a gate and solidifying the molten metal, wherein a plurality of protrusions for forming a hole are provided in the upper mold, and each protrusion is provided. Are provided with cooling means, respectively, these cooling means,
The cooling capacity of the inner protrusion relatively closer to the center of the mold is set to be larger than that of the outer protrusion relatively closer to the periphery of the mold. Characterized in that a spot cooling means set so as to suppress the occurrence of the heat is provided.

Further, according to a method of casting a cylinder head according to the invention of claim 10 of the present application (hereinafter referred to as the tenth invention of the present application), a method of casting a cylinder head between a pair of upper and lower A casting method in which a molten metal is injected and filled into a casting cavity formed in the lower mold through a gate provided in the lower mold, and the molten metal is solidified to cast a cylinder head of an engine. A plurality of protrusions for forming are provided, and cooling means are provided on each of the protrusions, and the cooling capacity of these cooling means is set such that an inner protrusion relatively closer to the center of the mold has an outer protrusion relatively closer to the periphery of the mold. It is characterized in that it is set so as to be larger than that of the part.

Still further, a method of casting a cylinder head according to the invention of claim 11 of the present application (hereinafter referred to as an eleventh invention of the present application) is a method of casting a cylinder head which is provided so as to be capable of coming and going. A casting method in which a molten metal is injected and filled into a casting cavity formed by the lower mold and a side wall, and the molten metal is solidified to cast a cylinder head of the engine. At least one of the lower mold and the lower mold is provided with spot cooling means set so as to suppress heat propagation in directions other than the predetermined direction.

Furthermore, a method of casting a cylinder head according to the invention of claim 12 of the present application (hereinafter, referred to as a twelfth invention of the present application) provides a method of casting a pair of upper and lower dies which are provided so as to be able to come and go. A casting method in which a molten metal is injected and filled into a casting cavity formed by the lower mold and a side wall, and the molten metal is solidified to cast a cylinder head of the engine. A plurality of protrusions for forming a hole are provided, and cooling means are provided for each of the protrusions, and the cooling capacity of these cooling means is such that the inside protrusion relatively close to the center of the mold is relatively close to the periphery of the mold. The lower die is provided with spot cooling means set so as to suppress heat propagation in directions other than the predetermined direction, while being set to be larger than that of the outer protrusion. It is.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, taking as an example a case where the present invention is applied to the casting of a cylinder head of an automobile engine. 1 and 2 are an explanatory front view and an explanatory side view of a casting apparatus according to the present embodiment. This casting apparatus A is for a so-called low pressure casting process, and has a lower mold DL
The upper platen 1 and the upper die DU are attached to the lower platen 1 and the upper platen 2, respectively, and the upper platen 2 is driven vertically with respect to the lower platen 1. In other words, the upper mold DU can move up and down with respect to the lower mold DL, so that the two can be separated from each other. ). As will be described in detail later, a plurality of slidable side dies forming the side wall of the casting cavity are attached to the upper die DU.

Below the lower platen 1, a holding furnace FH for supplying a molten metal at the time of casting is arranged, and the molten metal is supplied from a lower mold DL side. In the present embodiment, for example, an aluminum (Al) alloy is used as a material for casting the cylinder head, and the holding furnace F
The molten metal of the Al alloy is stored in H. This holding furnace FH
Is preferably fixed on a trolley 4 (holding furnace trolley), and can be moved with respect to the lower platen 1 as needed by driving the holding furnace trolley 4.
The internal structure of the holding furnace FH and the holding furnace F
The outline of the low pressure casting method using H will be described later.

In the casting apparatus A, two carts BC, which can advance and retreat into the mold opening space K when the upper mold DU rises to form the mold opening space K with the lower mold DL. A BP is provided (not shown in FIG. 2 to avoid complicating the drawing). First cart B
P is basically a lower DL, as will be described in detail later.
And a cast product from the upper die DU, and is hereinafter referred to as a product take-out cart as appropriate. Further, as will be described in detail later, the second carriage BC basically performs setting of a core or the like to the lower mold DL and application of a mold wash to the upper mold DU. As appropriate
It is called a core cart. Further, the first and second carriages B
P and BC can run on a common rail 3. The first and second trucks BP and BC
Details of the structure, operation, and the like will be described later.

Next, the holding furnace FH provided in the low-pressure casting apparatus A will be described. FIG. 3 is an explanatory vertical cross-sectional view of the holding furnace and the mold, schematically illustrating the internal structure of the holding furnace FH. As shown in this figure, the holding furnace FH is formed in a box shape with an open top, and a crucible 5 for storing a molten metal (a molten metal) is accommodated therein while being supported on a base 5B. ing. On the inner wall surface of the holding furnace FH, a heater 8 for heating and holding the molten metal in the crucible 5 at a predetermined temperature is provided. The upper opening of the holding furnace FH has a detachable furnace lid 7.
Thus, an airtight pressurized chamber Rp that covers the crucible 5 is formed inside the holding furnace FH.

A through hole 7h is formed at the center of the furnace lid 7, and a stalk 6 is fitted into the through hole 7h. The Stoke 6 has a distributor 9 on the upper side.
While its lower part is immersed in the molten metal in the crucible 5. The distributor 9 distributes and supplies the molten metal from the crucible 5 to each gate Di when the mold D is provided with a plurality of gates Di.
(That is, the upper surface of the furnace lid 7) and the lower surface of the mold D (that is, the lower surface of the lower mold DL). In the present embodiment, a plurality of (for example, four) gates Di are provided in the lower die DL. The mold D is, as described later, an upper mold D
U, a lower DL, and a plurality of side DSs, and the upper DU, the lower DL, and each side DS of each of these types.
An oil jacket core C #, a water jacket core CW, and a port core CP are arranged in this order from the top inside the casting cavity #c formed by the respective inner surfaces of the above. The cavity #c communicates with the inside of the distributor 9 via a gate Di formed in the lower mold DL.

The holding furnace FH is provided with an air supply passage 81 for supplying pressurized air to the pressurizing chamber Rp, and the pressure of the pressurized air supplied through the air supply passage 81 is set to the crucible FH. By acting on the surface of the molten metal in the stalk 6, the molten metal in the stalk 6 is pushed up. Then, the pushed molten metal is supplied from the stoke 6 to the distributor 9 and the gate D.
Via i, it is supplied and filled into the casting cavity #c of the mold D. An open / close air supply valve 82 for switching between supply and stop of pressurized air is provided in the air supply path 81.
And a pressure control valve 83 for adjusting the pressure of the pressurized air is provided in the air supply passage 81 upstream of the open / close type air supply valve 82. The pressure control valve 83 is provided with a servo mechanism 84 for controlling the opening thereof, and the pressure control valve 83 and the servo mechanism 84 increase the pressure applied to the molten metal surface in the crucible FH. A variable pressure control means 85 for changing the pattern is provided.

On the other hand, a ring-shaped insulator 86 is inserted into the upper mold DU of the mold D, and the upper part of the upper mold DU on both sides of the insulator 86 is filled with molten metal in the casting cavity #c. Two wirings 87 that are sometimes conductive are connected. Further, both the wires 87 are provided with a molten metal filling detection circuit 8 for sending out a filling signal when the two wires 87 are electrically connected to each other.
8 is electrically connected. Insulator 86, wiring 8
7 and the molten metal filling detection circuit 88 constitute a filling detection sensor 89 for detecting the filling of the molten metal into the cavity #c. Further, the molten metal filling detection circuit 88 is electrically connected to a pressure pattern control means 90 for changing a pressure pattern of the pressure variable control means 85, and the pressure pattern control means 90 has a molten metal casting cavity #c. After the start of the supply to the inside, a timer 94 for transmitting an elapse signal when a preset predetermined time elapses is electrically connected. The pressurizing pattern control means 90 includes, for example, a so-called CP
U (central processing unit) is built in, and the pressure pattern of the variable pressure control means 85 is changed based on a filling signal from the filling detection sensor 89 or a passage signal from the timer 94.

FIG. 4 is a block diagram schematically showing a pressurization control system of the casting apparatus A. As shown in this figure, in the above-described pressurization control system, an open / close
(ON) A pressurization start signal switch 95 that outputs an ON signal when the supply of pressurized air to the pressurizing chamber Rp is started and a filling detection sensor when the molten metal is filled into the casting cavity #c. A filling signal switch 96 for outputting an ON signal in response to a filling signal sent from 89 and a casting completion switch 97 for outputting an ON signal when casting is completed are provided. These switches 95, 96 and 97 are pressurized. It is electrically connected to the pattern control means 90. The timer 94 is connected to the pressurization pattern control means 90, and is connected to a pressurization start signal switch 95 and a casting completion switch 97. Then, it is set to start when an ON signal is received from the pressurization start signal switch 95, to output an ON signal when a predetermined time t2 has elapsed after the start, and to reset when receiving an ON signal from the casting completion switch 97. .

More preferably, the pressure pattern control means 90 comprises first and second two CPUs 91 and 92.
have. When receiving an ON signal from the pressurization start signal switch 95, the first CPU 91 controls the pressure variable control means 85 to rapidly increase the pressure in the pressurization chamber Rp,
After the start of pressurization, after a predetermined time t1 has elapsed, the pressure increasing speed is reduced, and when an ON signal is received from either the filling signal switch 96 or the timer 94, the pressure at that time is maintained,
When receiving an ON signal from the casting completion switch 97, the pressurizing chamber R
The CPU is set to output a first pressure signal of a pressure pattern for returning the pressure in p to normal pressure.

When the second CPU 92 receives an ON signal from either the charging signal switch 96 or the timer 94, the second CPU 92 increases the pressure in the pressurizing chamber Rp. When the pressure reaches a predetermined value, the second CPU 92 reduces the pressure at that time. The CPU is set so as to output a second pressurizing signal of a pressurizing pattern that maintains the pressure and returns the pressure in the pressurizing chamber Rp to the normal pressure when receiving an ON signal from the casting completion switch 97. As described above, the first and second output signals respectively output the first and second pressure signals having different pressure patterns.
The second CPUs 91 and 92 and the adding circuit 93 constitute a pressure pattern control unit 90. Adder circuit 93
Are the first pressure signal from the first CPU 91 and the second CPU 9
2 is a circuit for adding the second pressurizing signal from the second pressurizing signal to the servo mechanism 84.

Next, the mold D used in the low-pressure casting apparatus A will be described. FIG. 5 is an explanatory bottom view schematically showing the structure of the upper mold DU when viewed from the mold-matching surface side (that is, from below). As described above, the upper mold DU is provided so as to be able to contact and separate from the lower mold DL in the vertical direction. DS1, DS2 and D
S3) is attached. In the present embodiment, the mold D is more preferably a so-called two-piece casting mold in which two castings are obtained in one casting step. As can be seen from FIG. Also in the upper mold DU, two mold parts are formed symmetrically on one mold board 110.

Each of these left and right mold portions is provided with a plurality (four in this embodiment) of projections 111 for forming plug holes at the center thereof, and a plurality of protrusions 111 on both sides thereof (this embodiment). (5 in each case) are provided with protrusions 112 for forming bolt holes. The protrusion 111 for forming the plug hole is for forming a hole for inserting a spark plug into the cylinder head, and the protrusion 112 for forming the bolt hole is for forming a bolt hole in the cylinder head. belongs to. Each of the above molds (upper DU,
Both the lower mold DL and the side mold) are made of, for example, steel.

A plurality of (in this embodiment, a total of six) side type DSs (two sets each of DS1, DS2 and DS3) are attached to the upper die DU.
1, DS2 and DS3 have cylinder devices 121,
122 and 123 (side-type drive cylinders) are additionally provided. By driving these cylinder devices 121, 122 and 123, each side type DS1, DS1
DS2 and DS3 can be respectively slid along the mold plate 110 of the upper mold DU (that is, in a direction substantially orthogonal to the mold closing direction of the upper mold DU and the lower mold DL).

These side type DS1, DS2 and DS3
When the mold D is closed to form a casting cavity, such as at the time of casting and application of a mold wash, as described later, as shown in FIG. 5, they are slid inward and closed. On the other hand, when the cast product is taken out of the mold D after the completion of casting, the upper mold DU is raised and the upper and lower molds D
After opening U and DL, these side type DS1, DS2
And DS3, respectively, are slid outward and are opened.

As will be described later, the lower mold DL also has two mold sections formed symmetrically on one mold board 130 in correspondence with the upper mold DU, and is formed at the center of the left and right mold sections. A sand wall 138 is attached so as to separate both mold portions. This sand wall 138 is more preferably assembled to the lower mold DL in the same assembling step when assembling the cores C #, CW and CP to the lower mold DL. And like this,
With the cores CО, CW and CP and the sand wall 138 assembled to the lower mold DL, the upper mold DU is lowered to lower and upper molds D.
When U and DL are closed, the sand wall 138 assembled to the lower mold DL is located at the center of the left and right mold parts of the upper mold DU, and one of the side walls of the casting cavity of each of the left and right cylinder heads is formed. Will be. That is, the casting cavity of each cylinder head is formed by three movable side dies DS1, DS2, and DS3 provided in the upper die DU, and a fixed sand wall 130 set in the lower die DL. (Side wall surface) is formed.

FIG. 6 is an explanatory plan view of the lower mold DL.
In this lower mold DL, two mold parts are formed symmetrically on one mold plate. However, in FIG. 6, only one mold part (right side) is shown, and the left and right are the targets. Except for this point, detailed illustrations of the other side (left side) mold portion formed exactly the same are omitted. As shown in FIG. 7, the lower die DL is provided with baseboard receiving portions for assembling the cores C #, CW and CP, as will be described later, on each of the left and right die portions. That is, the first and second baseboard receiving portions 131 and 132 arranged at a predetermined interval in the longitudinal direction of each mold portion, and at a predetermined interval from each other so as to extend along the longitudinal direction of each mold portion. Third and fourth baseboard receiving portions 133 and 134 are provided.

The first and second skirting board receiving portions 131 and 132 are skirting board receiving portions for assembling the above-mentioned water jacket core CW, and receive the skirting board of the water jacket core CW. It is. In addition, the third
The fourth skirting board receiving portions 133 and 134 are skirting board receiving portions for assembling the above-described skirting board of the port core CP, and receive the skirting board of the port core CP. As shown in detail in FIG. 8, the oil jacket core C #, the water jacket core CW, and the port core CP are assembled to the lower mold DL in order from the top using the above baseboard receiving portions 131 to 134 in detail. .

A method of assembling these cores C #, CW and CP into the lower DL will be described below. In the present embodiment, both extend in the longitudinal direction of the cylinder head,
Further, with respect to the oil jacket core C # and the water jacket core CW arranged vertically, the water jacket core CW arranged below includes first and second baseboards 141 provided at both ends thereof. And 142 are assembled to the lower mold DL, and the oil jacket core CО is
The baseboards 143 and 144 provided at both ends thereof are supported by the water jacket core CW, and are assembled to the lower mold DL. In the present specification, the term “baseboard” includes both those provided integrally with the core body and those provided separately and used in combination with the core body.

That is, as shown in FIG. 11, the water jacket core CW set on the lower side has first and second baseboard portions 141 and 142 provided at both ends thereof.
Concave first and second engaging portions 141h and 142h that open downward are formed on the baseboard portions 141 and 142, respectively. On the other hand, the first and second skirting board receiving portions 131 and 132 of the lower die DL are formed with first and second skirting board locking portions 131a and 132a, which protrude upward, respectively. Then, the engaging portions (first and second engaging portions 141h and 142h) of the first and second baseboard portions 141 and 142 are replaced with the respective widths of the first and second baseboard receiving portions 131 and 132. The water jacket core CW is assembled to the lower mold DL by being fitted into and engaged with the wooden locking portions (first and second baseboard locking portions 131a and 132a) from above.

The oil jacket core C # set on the upper side is also provided with skirting portions 143 and 144 (third and fourth skirting portions) at both ends thereof. Are formed with concave third and fourth engaging portions 143h and 144h that are open downward as in the case of the water jacket core CW. On the other hand, on the upper surfaces of the first and second baseboard portions 141 and 142 of the water jacket core CW, convex third and fourth baseboard engaging portions 141a and 142a protruding upward are formed, respectively. ing.

Then, each of the engaging portions of the third and fourth baseboard portions 143 and 144 (the third and fourth engaging portions 143h)
And 144h) with the first and second baseboard sections 141 and 1
42. Each of the baseboard locking portions (third and fourth
Of the water jacket core CW by fitting the oil jacket core C # into the baseboard engaging portions 141a and 142a) of the water jacket core CW.
It is assembled to the lower mold DL via 41 and B142. In addition, the upper mold DU is lowered and the upper and lower molds DU and DL
Are closed, the oil jacket core CО
The upper inner surfaces of the side dies DS1 and DS2 that have descended together with the upper die DU are in contact with the upper surfaces of the baseboard portions 143 and 144.

Thus, the two long cores CW, C
Among them, the oil jacket core C arranged on the upper side
Are mounted on the lower die DL by supporting the baseboards 143 and 144 on the baseboards 141 and 142 of the water jacket core CW arranged on the lower side. Are integrated into a mold (lower mold DL) via the baseboard of
Compared to the case where W and C # are individually assembled into the mold, the distance between the shaft cores of both cores CW and C # can be kept very stably at a constant value. As a result, each core CW,
The thickness control between the passages (water jacket and oil jacket) corresponding to CО can be performed reliably.

By adopting such a configuration,
It is also possible to combine both cores CW and CО in advance and to attach the combined core (CW + CО) to the lower die DL, thereby reducing the man-hour for assembling the core, and In the case of assembling, the number of actuators can be reduced, and the structure of the core assembling apparatus can be simplified.

Further, in the present embodiment, FIGS.
As shown in detail in FIG. 3, the inner surface of the first engaging portion 141h and the outer surface of the first baseboard engaging portion 131a are set so that their shapes and dimensions are substantially the same. The first engaging portion 141h is provided on the first baseboard engaging portion 131a.
There is no gap for the whole surface (4 surfaces including the tapered surface),
Therefore, the entire surface is immovably engaged. Further, the second baseboard locking portion 132a is provided with a core CW.
Only in the longitudinal direction, when the thickness of the convex portion is set smaller than the concave portion width of the second engaging portion 142h by a predetermined amount, and when the core CW is assembled to the lower mold DL, the second width The positional relationship between the wooden locking portions 132a is set so that a gap of a predetermined amount or more is provided on both sides in the longitudinal direction.

On the other hand, as can be clearly understood from FIG. 12, in the lateral direction of the core CW, the inner surface size of the second engaging portion 142h and the outer surface size of the second baseboard engaging portion 132a are substantially equal. The second engagement portion 142 is set to be substantially the same.
h engages with the second baseboard engaging portion 132a without any gap in the lateral direction, and therefore, cannot move in this direction. That is, the second engagement portion 1
Reference numeral 42h is adapted to be movable only in the longitudinal direction of the core CW with respect to the second baseboard engaging portion 132a and to be immovable in the other directions.

As described above, the first engaging portion 141h provided at one end of the water jacket core CW directly assembled to the lower die DL is the first baseboard engaging portion of the mold (lower die DL). On the other hand, the second engagement portion 142h provided on the other end side of the water jacket core CW is engaged with the second jacket 131a of the lower mold DL.
The core CW can move only in the longitudinal direction of the core CW and cannot move in the other directions.
In the longitudinal direction, the difference in the amount of thermal expansion between the core CW and the lower mold DL can be effectively absorbed. Due to the difference in the amount of thermal expansion, defects such as cracks and breakage occur in the core CW. That can be prevented.

Further, the third and fourth skirting board engaging portions 141a and 142a provided on each of the skirting boards 141 and 142 at both ends of the water jacket core CW and the water jacket core CW are disposed above. The third is provided on each of the baseboards 143 and 144 at both ends of the oil jacket core C #.
The first and second baseboard locking portions 131 provided on the lower mold DL also and the fourth engagement portions 143h and 144h.
a and 132a and the first and second engaging portions 141h and 142h provided on the water jacket core CW, the third engaging portion 1
43h is immovably engaged with the third baseboard engaging portion 141a, while the fourth engaging portion 144h is movable only in the longitudinal direction of the core with respect to the fourth baseboard engaging portion 142a. , So that it is immovably engaged in other directions.

In this way, the oil jacket core C # is accurately positioned without causing a positional shift with respect to the water jacket core CW, and the thermal expansion amount of both C # and CW is determined in the longitudinal direction of these cores. The difference can be effectively absorbed. As a result, when the cores CО and CW are set in advance or during casting,
Due to the difference in thermal expansion between CО and CW, core CО
Also, it is possible to prevent the occurrence of defects such as cracks and breaks in the CW.

Also, in the present embodiment, the above-mentioned 2
The gas generated in the long cores (oil jacket core CО and water jacket core CW) is converted into each core CО,
Suction from the baseboard portion of the CW and discharge to the outside. That is, as shown in detail in FIG.
On the fourth skirting part 144 of the oil jacket core C # and the second skirting part 142 side of the water jacket core CW, when the upper mold DU is lowered to close the upper and lower molds DU and DL, The outer surfaces of the baseboard portions 144 and 142, the surface of the lower die DL including the outer surface of the second baseboard receiving portion 132, and the inner surface of the side die DS1 that contacts the upper surface side of the baseboard portion 144 of the oil jacket core C #. Thus, the closed space 101 is formed.

One end of, for example, a flexible hose 102 communicating with the closed space 101 is connected to the side surface of the side type DS2, and the other end of the hose 102 is connected to a vacuum pump as gas suction means. 103.
Then, the vacuum pump 103 is driven to drive the closed space 10.
1, the oil jacket core CО
The gas generated by the gasification of the binder of the water jacket core CW during casting is sucked and discharged to the outside of the casting cavity.

As described above, the cores C # and CW are obtained from the baseboard portions 144 and 142 of the CW at the time of casting.
And the suction means 103 (vacuum pump) for sucking the gas generated by the CW and the CW is provided, so that even if the cores C # and CW are long, the gas generated inside the cores C # and CW is removed by the baseboard portion 144 and Forcibly sucked from the casting cavity 142 and quickly discharged to the outside of the casting cavity, it is possible to effectively prevent gas defects from occurring in the obtained casting.

In this case, both cores CО and C
Since W is integrally assembled in the mold (lower mold DL) via the baseboard portions 144 and 142, even if one core does not face the closed space 101, the vacuum pump Even if it is substantially shut off from 103, gas is sucked from the baseboard of the other core, so that gas generated inside the one core is also effectively discharged to the outside of the mold. It is possible.

In the present embodiment, the water jacket core CW and the oil jacket core C # are assembled to the lower mold DL as described above, so that the baseboards of these cores CW and C # are assembled. At least a part of the mold surface corresponding to the side surface of the cylinder head is formed by the inner side surface. That is, the respective inner surfaces 141f and 142f of the baseboard portions 141 and 142 of the water jacket core CW (see FIG. 11) and the respective inner surfaces 143f of the oil jacket core CОbaseboard portions 143 and 144.
And 144f form at least a part of the mold surface corresponding to the side surface of the cylinder head.

As described above, by forming at least a part of the mold surface corresponding to the side surface of the cylinder head by the inner side surfaces 141f to 144f of the core boards 141 to 144 of the cores CW and C #, the cores CW and C CО baseboard 141
Using ~ 144, a part of the mold surface can be formed. In this case, since the heat transfer to the mold part where a part of the mold surface is formed on the side surface of the core made of molding sand as the main raw material is greatly suppressed as compared with the other mold parts, the molten metal after the casting step It is possible to give directionality to cooling of the substrate.

Thus, the transfer of heat from the gate Di provided on the mold (lower mold DL) on the side where the water jacket core CW is assembled to the mold (upper mold DU) on the far side is suppressed, and Thus, it is possible to give directionality to cooling of the molten metal after the casting step so that the molten metal is solidified from a portion as far as possible to the gate Di. That is, by cooling and solidifying the molten metal after the casting process under such directivity, the gas present in the casting cavity is gradually pushed to the gate Di side, and finally accumulated in the gate. It is possible to finish coagulation in the state.
Since the sprue portion is cut and removed as an unnecessary portion after the completion of casting, the cast product itself is less likely to have gas remaining, and the occurrence of casting defects can be effectively suppressed. .

Further, as can be clearly understood from FIGS.
A third die extending in a direction substantially orthogonal to the water jacket core CW and the oil jacket core C # is provided on the lower mold DL.
As cores, port cores CP corresponding to the supply / exhaust ports of the cylinder head are assembled in a state where the baseboards 145, 146 are supported on the mold side walls including the baseboard receiving parts 135, 136. Baseboard CP for Port Core 14
At least a part of the mold surface corresponding to the other side surface of the cylinder head is formed by the inner side surfaces 145f and 146f of 5,146. Particularly, with respect to the port core CP on the left side in FIG. 7 (that is, the center side of the lower mold DL and the right side in FIG. 8), at least a part of the mold side wall supporting the baseboard 145 is a sand wall 138. It is configured.

Therefore, also for the mold portion including the mold surface corresponding to the other side surface of the cylinder head, for the same reason as described above, the heat transfer is greatly suppressed as compared with the other mold portions. Directivity is given to the cooling of the molten metal after the casting process so that the molten metal is solidified from a portion as far as possible to the gate Di, which can contribute to suppression of generation of casting defects.

Further, in the present embodiment, as can be clearly understood from FIG.
Outer surface of baseboard 141 and oil jacket core C #
When the upper die DU is closed to the lower die DL on the outer surface of the baseboard 143 of the side die 143, the tapered inner surface 12 of the side die DS1 is closed.
Tapered portions 141g and 143g for guiding the Smooth 7 smoothly are provided. Each core CW and CО
Since the guide tapered portions 141g and 143g are provided on the outer side surfaces of the baseboards 141 and 143, when the upper mold DU is closed to the lower mold DL,
In particular, the closing operation of both types can be smoothly performed without the necessity of separately providing a guide portion.

Further, in this embodiment, as can be clearly understood from FIG. 8, when the upper die DU is closed to the lower die DL on the outer surface of the baseboard 146 of the port core CP, A guide tapered portion 146g for smoothly guiding the tapered inner surface 126 of the side type DS3 is provided. More preferably, a similar tapered portion 136g is provided on the outer surface of the baseboard receiving portion 136. Such a tapered portion 146 g for guiding is provided on the outer surface of the baseboard 146 of the port core CP, and more preferably, the same tapered portion 13 is provided on the outer surface of the baseboard receiving portion 136.
Since the 6 g is provided, when the upper mold DU is closed to the lower mold DL, the closing operation of both the molds can be smoothly performed without particularly having to separately provide a guide portion.

Further, in the present embodiment, the upper DU
The upper mold DU is provided with side molds DS (DS1 to DS3) slidable in a direction substantially perpendicular to the mold closing direction of the lower mold DL, as shown in FIGS. 10 (a) and 10 (b). In addition, the upper die DU is provided with a lower guide portion 119a located below the side die DS and guiding the sliding operation of the side die DS. This lower guide part 11
Both end portions of 9a are connected to a horizontal guide portion 119b, and the pair of horizontal guide portions 119b and the lower guide portion 119a form a frame-shaped slide guide 119 for guiding the slide operation of the side type DS. Is formed. Thereby, the slide operation of the side type DS can be smoothly performed without the need to separately provide a guide portion.

In the present embodiment, the solidification of the molten metal after casting is promoted in the mold D, and the temperature (mold temperature) of the mold D when the mold D is applied to the mold D is appropriately maintained. For this purpose, the mold temperature of the mold D is controlled to be cooled within a predetermined range. Next, cooling control of the mold D according to the present embodiment will be described. First, the cooling control of the upper DU will be described. As described above, each of the left and right mold portions of the upper mold DU is provided with a plurality of plug hole forming protrusions 111 at the center thereof, and a plurality of bolt hole forming protrusions 112 on both sides thereof. (See FIG. 5). In the present embodiment, these protrusions 111 and 112 are provided with a cooling control mechanism for the upper die DU.

That is, as shown in FIGS. 15 and 16, a cavity 111h extending in the axial direction is provided inside the projection 111 for forming a plug hole. As shown in detail in FIG. 16, an introduction pipe 114 for introducing a cooling medium into the inside of the cavity 111h.
And a discharge pipe 115 for discharging the cooling medium to the outside of the cavity 111h are inserted respectively. The introduction pipe 114 is connected to a cooling medium supply source (not shown),
On the other hand, the discharge pipe 115 is connected to a cooling medium recovery device (not shown). The cooling medium circulating system including the introduction pipe 114, the cooling medium supply source (not shown), the discharge pipe 115, and the cooling medium recovery device (not shown) constitutes cooling means in the protrusion 111 for forming the plug hole. ing.

As shown in detail in FIG. 17, a cavity 112h extending in the axial direction is also provided inside the protrusion 112 for forming a bolt hole, and a cooling medium is provided in each cavity 112h. An introduction pipe 116 for introduction into the inside of the portion 112h is inserted. In the case of the protrusion 112 for forming a bolt hole, the cooling medium introduced into the cavity 112h is discharged to the outside from the opening of the cavity 112h. The introduction pipe 116 is connected to a cooling medium supply source (not shown) different from that for the projection 111 for forming a plug hole. The cooling means in the protrusion 112 for forming the bolt hole is configured.

In the present embodiment, in order to provide appropriate directivity for cooling the molten metal after casting and to obtain a high quality cast product with few defects, each of the projecting portions 111, 1
12, the cooling means provided in the mold DU
The inner protrusion relatively close to the center of the mold (that is, the protrusion 111 for forming the plug hole) is replaced with the outer protrusion relatively close to the periphery of the mold (that is, the protrusion 112 for forming the bolt hole).
The cooling capacity is set to be larger than that of the above. Specifically, a liquid (for example, water) is used as a cooling medium of the cooling means provided on the protrusion 111 for forming the plug hole, and a cooling medium of the cooling means provided on the protrusion 112 for forming the bolt hole is used as the cooling medium. Gas (for example, air) is used.

As described above, since the cooling means is provided on each of the projections 111 and 112 for forming the holes provided in the upper mold DU, the mold (the upper mold DU) farther from the gate Di is actively cooled. Then, it is possible to give directionality to cooling of the molten metal after the casting step so that the molten metal solidifies from a portion as far as possible to the gate Di. Further, regarding the cooling means provided on the plurality of protrusions 111 and 112, the cooling means provided on the inner side, which is relatively close to the center of the mold, has the protrusion for forming the outer bolt hole, which is relatively close to the periphery of the mold. Since the cooling capacity is set to be larger than that of 112, the molten metal having directivity such that the molten metal is gradually cooled from the central portion as much as possible from the central portion and the outer portion of the casting cavity. Cooling can be performed.

That is, when solidifying the molten metal after casting, the provision of the cooling means not only promotes the solidification of the molten metal but also enhances the solidification speed, and also utilizes the shape peculiar to the cylinder head. It is possible to perform cooling with an appropriate directivity, and it is possible to effectively suppress the occurrence of defects such as gas defects and to more stably obtain a high-quality cast product.

In particular, the cooling medium of the cooling means provided on the inner plug hole forming protrusion 111 is liquid (water), and the cooling medium of the cooling means provided on the outer bolt hole forming protrusion 112 is provided. Is a gas (air), the cooling means provided on the plurality of protrusions 111 and 112 by utilizing the difference in heat transfer characteristics between the liquid and the gas, the cooling means provided on the inner protrusion 111 relatively close to the center of the mold. Can be reliably set so that the cooling capacity is larger than that of the outer protrusion 112 which is relatively close to the periphery of the mold.

In particular, each of the above-mentioned projections 111 and 11
2 corresponds to at least a plug hole relatively close to the center of the cylinder head and a bolt hole relatively close to the periphery of the cylinder head, respectively. This allows the subsequent molten metal to be cooled and solidified with appropriate directivity.

Further, in the present embodiment, after the cooling operation of the cooling means provided on the inner protruding portion (that is, the protruding portion 111 for forming the plug hole) is stopped, the protruding portion 1
Although not specifically illustrated in order to eliminate the cooling medium (that is, liquid) remaining in the hollow portion 111h of the eleventh portion,
A purge air supply pipe (residual liquid removing means) for purging the air inside the hollow portion 111h is provided. By providing such a residual liquid removing means, the liquid as a cooling medium remains in the cavity 111h of the protrusion 111 without being temperature-controlled, so that the cooling means of the protrusion 111 at the time of casting in the next cycle. Thus, it is possible to reliably prevent the accuracy of the temperature control from decreasing when the is operated.
In addition, the generation of rust in the cavity 111h of the protrusion 111 can be prevented.

Next, the cooling control of the lower mold DL will be described. In the present embodiment, as shown in FIG.
Is provided with a spot cooling mechanism 151 set so as to suppress heat propagation in directions other than the specific direction. The spot cooling mechanism 151 includes a main body 152 that is fitted into a mounting hole 156 formed in a predetermined portion of the lower mold DL.
And a cooling medium passage 152 formed in the main body 152.
and a discharge pipe 154 for discharging the cooling medium from the cooling medium passage 152h. The main body 152 is formed in a substantially cylindrical shape by providing a cooling medium passage 152h therein.

The supply pipe 153 is connected to a cooling medium supply source (not shown), while the discharge pipe 154 is connected to a cooling medium recovery device (not shown). Cooling medium passage 152h formed inside main body 152
The supply pipe 153, a supply source (not shown) of the cooling medium, a discharge pipe 154 and a recovery device (not shown) for the cooling medium constitute a cooling medium circulation system of the spot cooling mechanism 151.

The spot cooling mechanism 151 has a mounting hole 156 in which the outer periphery of the main body 152 is provided in the lower mold DL.
And the front end surface of the main body 152 faces the casting cavity #c. As described above, since one end surface of the spot cooling mechanism 151 faces the casting cavity #c, the molten metal in this portion is selectively cooled by having directivity in the longitudinal axis direction of the main body 152. be able to. Further, since the outer periphery of the main body 152 is fitted in the mounting hole 156 provided in the lower mold DL, the heat transfer characteristic can be changed with the fitting part as a boundary.

In the present embodiment, while the lower mold DL is made of steel, the main body 152 is made of, for example, an aluminum alloy, and the material of the two is changed, so that the heat is applied to the boundary between the fitting portions of the two. Is changed so that the cooling by the spot cooling mechanism 151 has the above-described directivity. Alternatively or additionally, a gap may be provided between the fitting portions to suppress heat transfer from the fitting portions. Further, by providing a heat insulating layer such as a ceramic sprayed layer in the fitting portion between the two, heat propagation in directions other than the longitudinal axis direction of the main body 152 may be suppressed.

As described above, the spot cooling mechanism 151 set so as to suppress heat propagation in directions other than the predetermined direction (the direction facing the casting cavity #c in the longitudinal axis direction of the main body 152) is provided on the lower mold DL. As a result, a specific portion of the molten metal in the mold cavity #c can be cooled and solidified with directivity in a predetermined direction, and the occurrence of defects such as gas defects can be effectively suppressed to obtain a high quality cast product. Can be obtained more stably.

As described above, in the present embodiment,
A part of the mold surface corresponding to the side surface of the cylinder head is formed of a sand wall, and the sand wall 138 is attached to the lower mold DL.
The spot cooling mechanism 151 is provided near the sand wall 138 (see FIGS. 6 and 7). The spot cooling mechanism 151 is provided at a position as far as possible from the gate Di even in the vicinity of the sand wall 138. As described above, by providing the spot cooling mechanism 151 near the sand wall 138, the sand wall 138 having low heat transfer property and being difficult to be cooled.
Can be selectively forcibly cooled in the vicinity of.

Further, in the present embodiment, as described above,
Below the lower mold DL, there are provided a death and a writer 9 serving as a molten metal supply unit for supplying the molten metal to be injected into the casting cavity #c through each gate Di. On the other hand, a concave portion 105 having a predetermined depth is formed on the lower surface side of the lower die DL, and the supply pipe 153 and the discharge pipe 154 as the cooling medium path of the spot cooling mechanism 151 are formed in the concave space portion 105. Are located. Also, the distributor 9 and the gate Di are placed in the concave space 105.
A communication tube 106 is provided to communicate with. In addition, a screen mesh (wire mesh 109) is attached to each gate Di in order to prevent foreign substances or the like that adversely affect the mechanical properties of the cast product from entering the casting cavity #c. The wire mesh 109 is usually removed as the cast product is taken out, and is newly attached for each casting cycle.

As described above, the molten metal supply unit 9 (distributor) for supplying the molten metal to be injected into the casting cavity #c via the gate Di is provided below the lower mold DL. A predetermined space 105 is provided between the mold DL and the cooling medium paths 153 and 154 for the spot cooling mechanism 151 in the space 105, and a communication tube for communicating the distributor 9 and the gate Di. Since the cooling medium paths 106 and 106 are provided, the cooling medium paths 153 and 154 can be normally provided under the lower mold DL where it is difficult to secure a space.
The spot cooling mechanism 151 can be easily provided on the lower mold DL side.

As described above, the upper DU side is attached to the upper DU side.
Since the cooling means is provided in each of the projections 111 and 112 for forming the holes provided in the mold, the mold (upper die DU) on the side far from the gate Di is actively cooled so that the molten metal is as far as possible to the gate Di. Directionality can be given to the cooling of the molten metal after the casting step so that solidification occurs from a part. As for the cooling means provided on the plurality of protrusions 111 and 112, the cooling means provided on the inner protrusion 111 relatively close to the center of the mold (the protrusion for forming the plug hole) is replaced with the outer protrusion 112 relatively close to the periphery of the mold. Since the cooling capacity is set to be larger than that of the casting cavity (the protrusion for forming the bolt hole), the casting cavity.
As for the central part and the outer part of c, the molten metal having directivity such that the molten metal is gradually cooled from the central part as much as possible can be cooled.

On the other hand, a spot cooling mechanism 151 set to suppress heat propagation in directions other than the predetermined direction is provided on the lower mold DL side.
A specific portion of the molten metal in c can be cooled and solidified with directivity in a predetermined direction from the lower mold DL side. That is, when solidifying the molten metal after casting, while providing solidification of the molten metal by providing the above cooling means, not only simply increase the solidification rate,
By utilizing the unique shape of the cylinder head, it is possible to perform cooling with appropriate directivity, effectively suppressing the occurrence of defects such as gas defects, and stabilizing high quality cast products. You can get it.

In this embodiment, the spot cooling mechanism 151 is provided only in the lower mold DL, but it may be provided only in the upper mold DU or in both molds DU and DL.

Next, the first and second bogies BP and BC provided in the low-pressure casting apparatus A, particularly the second bogie (core bogie) BC, will be described. These trolleys BP and B
As described above, when the upper mold DU rises and the mold opening space K is formed between the upper mold DU and the lower mold DL (see FIG. 1), C can enter and exit the mold opening space K. The core bogie BC holds the core and the sand wall outside the mold opening space K, then advances (forwards) into the mold opening space K, lowers the held core and sand wall, and lowers the lower mold DL. Set to.

The core carriage BC is, as described later,
An application box T for applying the powder coating agent to the inner surfaces of the molds of the upper mold DU and the side mold DS is mounted, and the application box T is raised in the mold opening space K, as described below. A powder coating agent is applied to the inner surface of the upper mold (the surface facing the lower mold DL, which faces downward) and the inner surface of the side mold DS. In the present embodiment,
For example, a diatomaceous earth-based material was used as the coating agent. Instead, for example, another suitable coating agent such as one using carbon as a main raw material can be used. The upper mold DU and the side mold DS are lowered to be matched with the lower mold DL, and then the molten metal is supplied and filled into the cavity #c formed by the molds DU, DS and DL, so that a predetermined casting ( Cylinder head) is cast. Then, the obtained cast product is placed in a state where the upper mold DU is raised to form the mold opening space K, and the product take-out cart BP is formed.
Thus, the core carriage BC is taken out in a direction opposite to the standby position.

The core cart (second cart) BC is as follows:
This will be described in more detail with reference to FIGS.
The core bogie BC has a core setting device 10 mounted at a lower portion thereof. The core setting device 10 has a base plate 13 that can move up and down while being guided by the guide rods 12. In the lower part of the base plate 13, a plurality of holding claws 15 which are opened and closed in the paper surface direction in FIG.
Opening / closing mechanism 16 including an actuator for opening / closing 5
Is provided.

The core setting device 10 includes a positioning pin 17a which is disposed in parallel with the holding claw 15 and extends vertically.
have. The positioning pin 17a is substantially constituted by a piston rod of the cylinder device 17 in the vertical direction, the core bogie BC moves to a predetermined position in the mold opening space K, and the positioning pin 17a descends. Lower mold D
By being inserted into the positioning hole (not shown) of L, the positioning of the core bogie BC in the mold opening space K is performed.
In this positioned state, the setting of each core and the sand wall to the lower mold DL and the application of the powder coating agent to the inner surfaces of the upper mold DU and the side mold DS are performed.

The coating box T has an outer shell substantially constituted by a covering member 21.
As shown in FIGS. 1 to 23, a spray nozzle 22 for spraying a powder coating agent and a blow nozzle 23 for blowing blow air are held. The covering member 21 is formed in a box shape having an opening only at the upper side, and has a bottom wall portion and left and right front and rear side wall portions. Faces the inner surface of the upper mold. The cover member 21 is held by the core bogie BC so as to be able to move up and down at a position higher than the core setting device 10 (base plate 13), more specifically, at a position higher than the upper frame of the core bogie BC. . That is, the plate 24 is provided on the outer wall of the cover member 21,
A cylinder device 25 as a vertical driving means is provided between the core 4 and the frame of the core carriage BC. A guide rod 26 extending upward from the core carriage BC penetrates the plate 24 so as to be slidable in the vertical direction, and the cover member 21 is smoothly driven in the vertical direction according to expansion and contraction of the cylinder device 25. It has become so.

The components such as the cover member 21, the spray nozzle 22, and the blow nozzle 23 are shown in FIGS.
This will be described in more detail with reference to FIG. The covering member 21 has a flange portion 21a over its entire upper edge.
A packing 31 made of an elastic material such as rubber is fixed to the entire surface of the flange portion 21a. Thereby, as shown in FIG. 22, when the covering member 21 is raised in the mold opening space K and the packing 31 is pressed against the lower surface of the upper mold DU, the covering member 21 and the upper mold DU and Side type DS
Cooperate with each other to form a closed space M in the cover member 21.

At this time, in the present embodiment, a plurality of side dies DS provided so as to be switchable between a mold closed state for forming a closed volume and a mold open state for opening the volume,
As described above, all of the side molds DS are applied to the inner surface of each of the side molds DS and the upper mold DU after all the side molds DS are set in the mold closed state. It is not necessary to perform the application operation of the coating agent in two times as in the case where at least a part of the side die is supported by the lower die DL provided with the gate Di. That is, the coating agent can be applied to the inner surfaces of the upper mold DU and all the side molds DS in one application operation, and the efficiency of the application operation can be increased.

At the lower part of the front and rear side walls of the covering member 21,
Slits 32 are formed which extend in parallel with each other and extend over substantially the entire length of the cover member 21 in the left-right direction. An elongated rod-shaped holding member 33 is provided in the covering member 21, and each end of the holding member 33 penetrates the slit 32 slidably. A roller 34 as a running wheel outside the cover member 21 is rotatably attached to one end 33a of the holding member 33. The roller 34 runs on a guide rail 35 fixed to the outside of the side wall of the cover member 21. You can run.

On the other hand, a nut member 36 is fixed to the other end 33 b of the holding member 33 outside the cover member 21. Have been combined. The screw rod 37 is rotatably held by the cover member 21, and one end thereof is connected to a rotary actuator (for example, an electric motor in the present embodiment) 38 as a driving means. Thus, for example, by rotating the actuator 38 in the normal direction, the nut member 36, that is, the holding member 33 is driven downward in FIG. 23, and by rotating the actuator 38 in the reverse direction, the holding member 33 is driven upward in FIG.

The spray nozzle 22 and the blow nozzle 23 are fixed to the holding member 33. As shown in detail in FIGS. 24 and 25, the spray nozzle 22 has an elongated cylindrical main body 22a having both ends closed, and the cylindrical main body 22a has an internal elongated common space 2a.
2b and a plurality of communication holes 22c respectively communicating with the common space 22b. Each communication hole 22c is formed in series at intervals in the longitudinal direction of the cylindrical main body 22a, and a nozzle member 22d is attached to each of the communication holes 22c. A pair of such spray nozzles 22 are provided along the longitudinal direction of the holding member 33 and spaced from each other, and both are fixed to the holding member 33. Each spray nozzle 22 is provided with a screw hole 39 for fixing to the holding member 33. The spray nozzle 22 is attached to the holding member 33 by the nozzle member 2.
The setting is performed so that 2d faces upward.

The blow nozzle 23 is also used for the spray nozzle 2
22 is substantially the same structure as that of FIG. 2, but there is no member corresponding to the nozzle member 22d, and the opening corresponding to the communication hole 22c is directly blow air outlet 23c (FIG. 22).
See). And this blow air outlet 2
The blow nozzle 23 is fixed to the holding member 33 so that 3c faces downward, that is, toward the bottom wall of the cover member 21. As in the case of the spray nozzle 22, a pair of the blow nozzles 23 are provided along the longitudinal direction of the holding member 33 and spaced from each other.

As described above, in the present embodiment, the coating agent applying means provided on the core bogie BC is combined with the upper mold DU and the plurality of side molds DS in the mold closed state to seal the coating. Covering member 2 as a closing member for forming a space
1 and a spray nozzle 22 as a coating mechanism positioned in the coating space 時 に at the time of forming the coating space {
In a state in which a closed space (application space) М is formed by using the cover member 21, the coating agent is applied by the spray nozzle 22 to the upper mold DU.
And it can apply automatically to the inner surface of each side type DS. Further, the above-mentioned mold-coating agent applying means comprises upper and lower molds DU / D
A second bogie (core) B that can move back and forth in the mold opening space K of L
C, the bogie BC is provided with a core assembling device 10 for holding the core and assembling the core into the lower mold DL, on the side opposite to the side on which the coating agent applying means is mounted. Since it is provided, the core can be automatically assembled in parallel with the automatic application of the mold wash.

The supply of the powder coating agent to the spray nozzle 22 is performed by the connection member 41 attached to the bottom wall of the cover member 21.
From a long flexible hose 42 disposed in the covering member 21. The hose 42 is connected to a common space 22b therein at a substantially middle portion in the longitudinal direction of the spray nozzle 22 so as to communicate therewith (see FIGS. 24 and 25). The supply of the blow air to the blow nozzle 23 is performed via the elongated flexible hose 43 passing through the slit 32 described above. Further, two suction ports 44 are formed in the bottom wall of the cover member 21 at a substantially central portion thereof. This suction port 44 is connected to a hose 45
Is connected to a suction device 46 (see FIG. 26).

FIG. 26 is a view for explaining a connection path to the spray nozzle 22, the blow nozzle 23 and the suction port 44. As shown in FIG. 26, the original air supplied from an air supply source (not shown) passes through a regulator 51, a filter 52, and a dryer 53 in that order, and becomes clean dry air adjusted to a predetermined pressure. The downstream side of the dryer 53 is branched into five branch paths parallel to each other. The branch system 61 serves as a supply system for the powder coating agent, and is connected to the spray nozzle 22 via an electromagnetic on-off valve 62, an ejector 63, and a high voltage application unit 64 in order. The ejector 63 includes a pneumatic on-off valve 65.
A powder coating agent storage tank 66 is connected through the opening, and in a state where the on-off valve 65 is open, the powder coating agent is sucked up from the tank 66 by air supplied from the system path 61, and the powder coating agent is The agent is sent under pressure to the spray nozzle 22.

The pneumatic on-off valve 65 has a branch system 67
The system 67 is connected to an electromagnetic on-off valve 68. Thus, the pneumatic on-off valve 65 is opened and closed according to the opening and closing of the electromagnetic on-off valve 68. The high voltage application unit 64 applies the powder coating agent so that a predetermined high voltage difference is generated between the upper die DU connected to, for example, a + (plus) electrode by the high voltage generator 64A. That is, adhesion of a powder coating agent using so-called electrostatic adsorption (that is, electrostatic coating of the coating agent) is performed. As described above, the electrodes were connected to the upper die DU, and the coating agent was electrostatically applied to the inner surfaces of the upper die DU and each side die DS.
The uniformity and adhesion of the state of application of the coating agent to the inner surface of the mold can be sufficiently improved as compared with the case of only ordinary spray application.

A branch line 69 is connected to the tank 66, and an electromagnetic on-off valve 70 is interposed in the branch line 69. When the on-off valve 70 is opened, the powder coating agent in the tank 66 is agitated, and the transfer of the powder coating agent to the ejector 63 is effectively assisted. The ejector 63
A branch line 71 is connected to the tip of the branch line 7.
1 is provided with an electromagnetic on-off valve 72. Thus, when the on-off valve 72 is opened, purge air is supplied to the spray nozzle 22 via the ejector 23. Further, a branch line 73 is connected to the blow nozzle 23, and the branch line
3 is provided with an electromagnetic on-off valve 74. And
By opening the on-off valve 74, blow air is blown out from the blow nozzle.

FIG. 27 shows an example of the relationship between the movement of the spray nozzle 22, the spraying of the powder coating agent from the spray nozzle 22, the blowing of blow air from the blow nozzle 23, the suction from the suction port 44, and the supply of purge air. It is a time chart shown. In the example shown in FIG. 27, after the spray nozzle 22 is moved from the original position, which is one end of the cover member 21, to the forward end, the spray nozzle 22 performs an operation of returning to the original position again. The reciprocating operation completes the application of the powder coating agent to the inner surface of the upper and side dies. In this case, the moving speed of the spray nozzle 22 is, for example, a constant speed. The application of the powder coating agent from the spray nozzle 22 is started from a position where the spray nozzle 22 is slightly advanced from the original position, is temporarily stopped from a position slightly before the advanced end to a position slightly after the advanced end, and then is again applied. The spraying of the mold agent is resumed, and the spraying of the powder coating agent ends shortly before returning to the original position. The blowing mode of the blow air is performed in the same manner as the blowing of the powder coating agent.

The start of the suction from the suction port 44 is the same as the start of the spraying of the powder coating agent. However, the end time of the suction is determined by the closed space M formed by the cover member 21.
Since the powder coating agent remaining inside is sucked and collected, the time is set to be much later than the end of spraying of the powder coating agent. That is, suction is performed for a while after the spray nozzle 22 returns to the original position. On the other hand, the supply of the purge air is started at a timing slightly before the end of the spraying of the powder coating agent. The supply of the purge air is continued for a while after the spray nozzle 22 returns to the original position, but the supply is stopped earlier than the end of the suction.

In this embodiment, more preferably,
The cylinder device 14 that drives the holding claws 15 for holding the core in the vertical direction is supported by a floating mechanism. That is, conventionally, for example, as shown in FIG.
Projection 21 projecting from the upper surface of baseboard 212 of core 211
3 is horizontally held by the clamper 215 and the core 211
Is generally assembled to the mold 219.

At this time, the assembling work is performed by positioning the engaging portion 212h of the baseboard 212 so as to correctly engage with the baseboard engaging portion 219a provided on the mold 219.
Actually, a positional shift occurs between the mold 219 and the core 211 due to a difference in thermal expansion amount between the two. And
When assembly is performed in a state in which this displacement has occurred (FIG. 31)
), In this conventional example, the clamper 215
Is released and the assembly is performed by utilizing the gravity of the core 211, so that the engaging portion 212h is attached to the baseboard engaging portion 219.
It is difficult to correctly engage with (a) (a). For this reason, there is a problem that if the core 211 is assembled in a raised state and casting is performed as it is, a defect occurs in the cast product.

In another conventional example, as shown in FIG. 32, for example, a baseboard 222 is opened and closed using a holding claw 225 opened and closed by a cylinder 226 in a state in which the upper surface of the baseboard 222 is stopped by a presser 227. Is clamped by applying a vertical force. In this case, it is possible to assemble while holding down the baseboard 222.
2 engaging portion 222h and mold 229 baseboard engaging portion 229a
If the misalignment occurs between them, there is a problem that the core 221 is damaged or broken.

In the present embodiment, as schematically shown in FIG. 30, the cylinder device 16a for opening and closing the holding claws 15 for holding the core 181 is a floating device 1
9 supported. A compression spring 18 is provided on the upper surface of the baseboard 182, and the upper end of the compression spring 18 is attached to the floating device 19. Therefore, the baseboard 182 is connected to the spring 1
8, it is always urged downward.

The floating device 19 is well known and widely marketed, and is locked (fixed) in a state where air pressure is applied thereto by the action of a built-in ball and pressurized air, for example. When the air pressure is not applied, the lock is released and a floating state (a state in which the air pressure is supported) is obtained. By supporting the upper end of the spring 18 via the floating device 19, the position of the upper end supporting portion of the spring 18 (therefore, the baseboard 182) can be freely moved within the floating range.

By adopting the above configuration, the baseboard 1
82 is engaged with the baseboard engaging portion 189 of the mold 189.
When the core 181 is set in the mold 189 by engaging with the a, even if a displacement occurs between the engaging portion 182h and the baseboard engaging portion 189a, the floating function of the floating device 19 is used. Alternatively, in addition to the above, the horizontal elasticity of the spring
2 can be finely and automatically adjusted, and while the tapered surface of the engaging portion 182h is guided by the tapered surface of the baseboard engaging portion 189a, and is urged downward by the urging force of the compression spring 18, the position of the engaging portion 182h is smoothly adjusted. And an accurate engagement state can be obtained. As a result, there is no fear that the core is lifted or damaged unlike the related art.

FIG. 28 and FIG.
3 shows an apparatus embodying an assembling mechanism. The cylinder device 16a for opening and closing the holding claw 15 for holding the core is supported by a floating device 19 located above the holding device, and a compression spring 18 is disposed on the upper surface of the baseboard 143 of the core C #. Has been established. The core holding mechanism including the holding claws 15, the cylinder device 14, the floating device 18, and the like is provided in a pair at both ends in the longitudinal direction of the core C #.

Next, the casting apparatus A configured as described above
33 to 3 show the casting process performed using
This will be described with reference to the flowchart of FIG. In this casting process, a series of steps is repeatedly performed. Here, for example, the description will be started from the time when a casting (product) of the previous cycle is cast and taken out of the mold D. After the casting is completed and the upper and lower molds DU / DL are opened, first, in step # 1, the first cart (product take-out cart) BP advances into the mold opening space K, and step #
At 2, the side molds DS (DS1 to DS3) are opened. Note that the mold opening in step # 2 may be performed in parallel with step # 1.

Next, in step # 3, the ejector mechanism (not shown) on the upper mold DU side is driven to take out the product from the upper mold DU. At this time, since a coating agent is applied to the inner surface of the upper mold DU, the product can be easily released from the upper mold DU. The product taken out is received above the first bogie BP. On the other hand, in the lower part of the first bogie BP, the wire mesh 109 held by the wire mesh holder (not shown) is set in the sprue Di provided in the lower mold DL in parallel with the above step # 2 and / or step # 3. (Step # 4).
Note that the wire net 109 used in the previous cycle is attached to the upper mold DU.
A rod-shaped sensor is provided to confirm that the fragments of aluminum or the residual aluminum lump from the previous cycle do not block the gate Di, and that the gate Di is normally opened before the wire mesh 109 is set. I am trying to make sure. Then, in step # 5, the first truck B
P retracts from inside the mold opening space K in the vertical direction. And
Instead, the second bogie (core bogie) BC advances into the mold opening space K (step # 6).

Then, on the upper side of the second carriage BC,
After all the side molds DS are closed in step # 7, the mold is applied to the inner surfaces of all the side molds DS and the upper mold DU (step # 8). On the other hand, in the lower part of the second bogie BC, the core is set (assembled) into the lower die DL by the core setting device 10 in parallel with the steps # 7 and # 8 (step # 9). ). At this time, three types of cores CW, CО are provided below the second carriage BC.
, CP and the sand wall 138 are held, and these cores CW, C # and CP and the sand wall 138 are set on the lower mold DL. Note that the core setting device 10 is provided with a rod-shaped sensor for confirming that the core used in the previous cycle does not remain in the lower mold DL due to breakage or the like, and prior to the core setting operation, It is ascertained that no broken core fragment remains at the core setting location of the lower mold DL.

The details of the application step (step # 8) and the core setting step (step # 9) of the coating agent will be described with reference to the flowchart of FIG. 34, focusing on the movement of the second carriage BC. . That is, as described above, when the upper mold DU is raised and the mold is opened, the core carrier BC is moved toward the mold opening space K (SP1). Next, in the mold opening space K, the core carriage BC is positioned using the positioning pins 17a (SP2). After this,
The setting of the core and the application of the powder coating agent are performed in parallel, the core setting is the processing of SP3 to SP5 in FIG. Is done.

When setting the core in the lower die DL, first, the base plate 13, that is, the core is lowered by the cylinder device 14 (SP3). After this, the holding claws 15
Is opened and the core is set to the lower mold DL (SP
4). Then, the base plate 13 is raised by the cylinder device 14 (SP5). When applying the powder coating agent, first, the cylinder device 25 applies the application box T
That is, the cover member 21 is raised (SP8). Then
As described above, the powder coating agent is applied to the inner surface of the upper mold (SP9), and the cylinder device 25 is applied.
As a result, the application box T is lowered (SP10).

When the steps SP5 and SP10 are completed, the positioning pins 17a are raised, and the positioning relationship between the core bogie BC and the lower mold DL is released (SP6). After that, the core carrier BC moves backward, that is, is moved outside the mold opening space K (SP7). still,
In the above-described coating agent application step, the present invention is not limited to the illustrated embodiment. An appropriate direction can be set according to the direction of the inner surface. In addition, the direction of the blow nozzle 23 can be set to an appropriate direction in consideration of the scattering effect of the powder coating agent.
Further, the application box T, that is, the covering member 21 may be configured separately and separately from the core carriage BC.

As described above, the plurality of side molds DS are all supported by the upper mold DU, and all the side molds DS are set in the mold closed state. Since the agent is applied, it is not necessary to perform the operation of applying the agent in two separate steps as in the case where at least a part of the side mold is supported on the lower mold DL. That is, the upper mold DU and all the side molds D are formed in one coating operation.
The coating agent can be applied to the inner surface of S, and the efficiency of the application operation can be increased.

In particular, when the upper and lower molds DU / DL provided so as to be able to contact and separate in the vertical direction are separated from each other, the mold applying agent applying means of the second carriage BC moves into the mold opening space K of both molds. Then, the coating agent is applied using the opening operation of both main molds DU / DL. Further, the above-mentioned mold-applying agent applying means comprises an upper mold DU and each side mold D.
Since the core is assembled to the lower mold DL while the mold is applied to the inner surface of S, both the application of the mold and the assembly of the core for the mold are performed. This can be performed in parallel, and the production efficiency of the entire casting process can be improved.

After the application of the coating agent (step # 8) and the core setting step (step # 9) as described above, the second carriage BC is retracted (step # 10).
U is lowered to close the lower mold DL (step # 11). Then, in step # 12, the inside of the holding furnace FH is pressurized to perform low-pressure casting. The details of the pressurization control in this pressurization step (step # 12) will be described with reference to the flowchart in FIG. 35 and the diagrams in FIGS. 36 to 38.

First, in step ST1, the air supply path 42
The pressurized air is supplied to the pressurizing chamber 20 from above, and the molten metal in the crucible 12 is pushed up.
0 and the mold is started by supplying it to the cavity 32,
In step ST2, the timer 60 starts. In this case, as shown in the pressurization pattern (a) in FIG. 36, after the supply of pressurized air is started, the pressure is rapidly increased until a time t1 at which the molten metal reaches the gate 40 of the mold 30 has elapsed. The molten metal is pushed up quickly to prevent the temperature of the molten metal from dropping, and after the lapse of the scheduled time t1 at which the molten metal reaches the gate 40, the pressure rising speed is reduced so that the molten metal is smoothly filled between the sand cores. Let it.

Next, in step ST3, it is determined whether or not the filling detection sensor 58 has detected the filling of the molten metal, based on the presence or absence of the filling signal. In order to prevent the core from spouting into the molten metal, in step ST4, the pressure in the pressure chamber 20 is increased as shown in the pressure pattern (b) of FIG. Therefore, the timer 60 is stopped in step ST5. If the filling detection sensor 58 does not detect the filling of the molten metal in step ST3, the process proceeds to step ST6 and receives the elapsed signal output from the timer 60 after the elapse of a predetermined time t2 after the start of the supply of the pressurized air. As shown in the pressure pattern (c), the pressure in the pressure chamber 20 is increased. In this way, even if the filling detection sensor 58 has a detection failure, the pressure in the pressurizing chamber 20 can be increased with the lapse of the predetermined time t2 after the start of the supply of the pressurized air. it can.
Next, the timer 30 is reset in step ST7 to prepare for the next casting step, and the casting is completed in step ST8.

FIG. 37 shows a specific pressure pattern of the pressure control method in the above embodiment. That is, the first CPU 70 and the timer 60 are activated simultaneously with the start of pressurization in the pressurization chamber 20, and after eight seconds from the start of pressurization, the first CPU 70 slows down the pressure rising speed, and when the filling detection sensor 58 outputs a filling signal (normally). 13 seconds after the start of pressurization), the first CPU 7
0 maintains the pressure at that time, while the second CPU 72 raises the pressure in the pressurizing chamber 20 and when the pressure in the pressurizing chamber 20 reaches a predetermined value (normally, 20 seconds after the start of pressurizing), the second CP 72
U72 also maintains the pressure at that time. In this case, the timer 60 outputs an ON signal 18 seconds after the start of pressurization, and the second CP
U72 is set to be activated, and even if the filling detection sensor 58 has a detection failure, the second pressure is applied 18 seconds after the start of pressurization.
The CPU 72 starts.

FIG. 38 shows a pressing pattern of a modification of the above-described pressing control method. In this modified example, a sprue passage sensor that outputs a passage signal when the molten metal passes through the sprue 40 is disposed in the lower mold 26 of the mold 30, and a third C port is provided in addition to the first CPU 70 and the second CPU 72.
Set up a PU. When the gate passage sensor outputs a passage signal (normally, 9 seconds after the start of pressurization), the first CPU
70 maintains the pressure at that time, while the second CPU 72
Increases the pressure in the pressurizing chamber 20 and causes the filling detection sensor 58
Based on the filling signal (usually 13 seconds after the start of pressurization)
The second CPU 72 maintains the pressure at that time, while the third CPU 72
The CPU sets the pressure pattern so as to increase the pressure in the pressure chamber 20. In this case, the timer 60 is set to output an ON signal and activate the third CPU at the earliest of 15 seconds after the start of pressurization and 5 seconds after receiving the passage signal from the gate passage sensor. Keep it.

When the pressurizing pattern is set as in this modification, the error that occurs between the passage of time and the degree of rise of the molten metal can be set to be small, so that the third CPU is started 15 seconds after the start of pressurizing. It can be started earlier than in the case of the specific example (18 seconds after the start of pressurization), so that the quality of the product can be kept high even when the filling detection sensor 58 has a poor detection. Further, since the gate passage sensor is provided, the pressure increasing speed until the molten metal passes through the gate 40 can be made faster than in the specific example, so that the temperature of the molten metal can be prevented from lowering. Further, while a gate passage sensor is required, a CPU having a simple function can be used as the first CPU 70, which is advantageous in cost.

As described above, in the low-pressure casting apparatus A,
The pressure variable control means operates to change the pressurization pattern according to the filling signal when the filling detection sensor is normal, and according to the elapsed signal when the filling detection sensor is detection failure, so that the detection state of the filling detection sensor is normal. The pressure pattern can be changed regardless of the defect. For this reason, even if a detection failure occurs in the filling detection sensor, the quality of the product can be maintained at an allowable level or more, and the occurrence of a product failure can be prevented.

The above pressurizing step (step # 12)
After or at the end of the process, in Step # 13, the solidification of the molten metal after casting is promoted,
In addition, in order to appropriately maintain the temperature (mold temperature) of the mold D when applying the coating agent to the mold D, a cooling step of controlling the mold temperature of the mold D to a predetermined range is performed. Thus, the casting process is completed, and the upper and lower molds DU / DL are opened (step #).
14) Returning to step # 1, a similar casting cycle is repeated.

In the above-described series of casting cycles, the time required in each step is, for example, as follows. That is,
The pressurizing step (Step # 12) was the longest, about 200 seconds, the cooling step (Step # 13) was about 40 seconds, and the core setting step (Step # 9) was about 20 seconds. And about all other processes, it took about 60 to 70 seconds in total. Therefore, step # 13
After finishing the cooling step, application of a mold wash (Step # 8)
Is only about 60 to 70 seconds.

That is, cooling is performed at such short intervals to promote solidification of the molten metal after casting, and thereafter,
If the cooling control of the mold is performed to improve the adhesion (adhesion) of the coating agent to the mold surface, both controls interfere with each other and good cooling control cannot be performed. Therefore, in the present embodiment, in the cooling for promoting solidification of the molten metal after casting (step # 13), the cooling means provided on the protruding portions 111 and 112 of the upper mold DU as described above uses the upper mold DU.
In consideration of the optimum temperature range (for example, 260 to 320 ° C.) of the upper mold DU at the time of applying the coating agent, specifically, the mold temperature of the upper mold DU is set to 260 to 320 ° C. The cooling of the mold temperature of the upper mold DU is controlled so as to fall within the range described above. Incidentally, in the case of the lower mold DL in which the gate Di is provided and the coating agent is not applied, the control range of the mold temperature is preferably, for example, 450 to 510 ° C.

That is, in the present embodiment, the upper mold DU is subjected to cooling control for accelerating the solidification of the molten metal after casting, and thereafter (approximately 60 to 70 seconds), the coating agent is applied to the mold surface. This means that cooling control for improving adhesion (adhesion) is also used. As described above, since the application of the mold wash is performed while the mold temperature of the upper mold DU is controlled to be cooled to a predetermined temperature range, the application can be performed at an appropriate mold temperature, and the upper mold DU and the side mold can be formed. This makes it possible to enhance the adhesion of the coating agent to the inner surface of the mold DS.

In the above embodiment, the mold D is a so-called two-piece mold. However, the present invention is not limited to such a case, but is a usual one-piece mold. Even if there is, it can be applied effectively. Further, in the above-described embodiment, all of the plurality of side types DS are movable types, but a part of them may be fixed types fixed to the upper type. Further, in the above-described embodiment, the case where the cylinder block of the engine is cast has been described as an example. Can be applied to As described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various improvements or design changes can be made without departing from the scope of the present invention.

[0125]

According to the cylinder head casting apparatus according to the first aspect of the present invention, since the cooling means is provided on each of the projections for forming the holes provided in the upper mold, the mold farther from the gate is provided. It is possible to give directionality to cooling of the molten metal after the casting step so that the (upper mold) is actively cooled so that the molten metal solidifies from a portion as far as possible to the gate. Further, as for the cooling means provided on the plurality of protrusions, the cooling ability of the inner protrusion relatively closer to the center of the mold is set to be larger than that of the outer protrusion relatively closer to the periphery of the mold. With respect to the central portion and the outer portion of the casting cavity, the molten metal can be cooled with directivity such that the molten metal is gradually cooled from the central portion as much as possible. That is, when solidifying the molten metal after casting, the provision of the cooling means not only promotes the solidification of the molten metal but also increases the solidification speed, and also utilizes the shape unique to the cylinder head to obtain appropriate directivity. Cooling can be performed, and the occurrence of defects such as gas defects can be effectively suppressed, and a high-quality cast product can be more stably obtained.

Further, according to the second aspect of the present invention, basically the same effects as those of the first aspect can be obtained. In particular, since the cooling medium of the cooling means provided on the inner protrusion is a liquid and the cooling medium of the cooling means provided on the outer protrusion is a gas, the difference between the heat transfer characteristics of the liquid and the gas is utilized. As for the cooling means provided on the plurality of protrusions, it is necessary to ensure that the inner protrusion relatively closer to the center of the mold has a larger cooling capacity than that of the outer protrusion relatively closer to the periphery of the mold. Can be done.

Further, according to the third aspect of the present invention, basically the same effects as in the second aspect can be obtained. In particular, the cooling medium (that is, liquid) remaining in the protrusion after the cooling operation of the cooling means provided in the inner protrusion is stopped.
Since the liquid as a cooling medium remains in the protrusion without being temperature-controlled, the temperature control is performed when the cooling means of the protrusion is operated during the next cycle of casting. It is possible to reliably prevent the accuracy of the device from decreasing. Further, generation of rust in the protruding portion can be prevented.

Further, according to the fourth aspect of the present invention, basically the same effects as those of any one of the first to third aspects can be obtained. In particular, since the protrusions correspond to at least a plug hole relatively close to the center of the cylinder head and a bolt hole relatively close to the periphery of the cylinder head, a plug hole and a bolt hole specific to the cylinder head are used. Thus, the molten metal after casting can be cooled and solidified with appropriate directivity.

Further, according to the cylinder head casting apparatus according to the fifth aspect of the present invention, heat propagation in a direction other than a predetermined direction is suppressed to at least one of the upper mold and the lower mold. Since the set spot cooling means is provided, a specific portion of the molten metal in the mold cavity can be cooled and solidified with directivity in a predetermined direction, thereby effectively suppressing the occurrence of defects such as gas defects. As a result, a high-quality cast product can be obtained more stably.

Further, according to the sixth aspect of the present invention, basically the same effects as in the fifth aspect can be obtained. In particular, the spot cooling means is configured by providing a cooling medium passage in a cylindrical member, and the cylindrical member has one end face facing the casting cavity. Can be selectively cooled by providing directivity in the direction of the longitudinal axis. In addition, since the outer peripheral portion of the cylindrical member is fitted in the mounting hole provided in the mold, it is possible to change the heat transfer characteristic with the fitted portion as a boundary. By changing the material, or by providing a heat insulating layer in the fitting portion, it is possible to easily perform a setting such that heat propagation in directions other than the longitudinal axis direction of the tubular member is suppressed.

Further, according to the seventh aspect of the present invention, basically the same effects as in the sixth aspect can be obtained. In particular, since a part of the side wall is formed of a sand wall and the spot cooling means is provided in the vicinity of the sand wall, it is possible to selectively forcibly cool the vicinity of the sand wall having low heat transfer property and being hardly cooled. .

Further, according to the eighth aspect of the present invention, basically the same effects as in any one of the fifth to seventh aspects can be obtained. In particular, a molten metal supply unit for supplying molten metal to be injected into the casting cavity via a sprue is provided below the lower mold, and a predetermined space is provided between the molten metal supply unit and the lower mold. A cooling medium path for the spot cooling means is arranged in the space, and a communication path for communicating the molten metal supply section and the gate is formed, so that it is usually below the lower mold where it is difficult to secure a space. A cooling medium path can be provided, and the spot cooling means can be easily provided on the lower mold side.

Further, according to the cylinder head casting apparatus of the ninth aspect of the present invention, the cooling means is provided on the upper mold side at each of the projections for forming the holes provided in the upper mold. ,
Actively cool the mold (upper mold) on the side far from the gate so that the molten metal solidifies from the part as far as possible to the gate.
Directivity can be given to cooling of the molten metal after the casting step. Further, as for the cooling means provided on the plurality of protrusions, the cooling ability of the inner protrusion relatively closer to the center of the mold is set to be larger than that of the outer protrusion relatively closer to the periphery of the mold. With respect to the central portion and the outer portion of the casting cavity, the molten metal can be cooled with directivity such that the molten metal is gradually cooled from the central portion as much as possible. On the other hand, since the lower mold side is provided with a spot cooling means set so as to suppress heat propagation in directions other than the predetermined direction, a specific portion of the molten metal in the mold cavity is moved in a predetermined direction from the lower mold side. Cooling and solidification with directivity can be performed. That is, when solidifying the molten metal after casting, while providing solidification of the molten metal by providing the above cooling means, not only simply increase the solidification rate,
By utilizing the unique shape of the cylinder head, it is possible to perform cooling with appropriate directivity, effectively suppressing the occurrence of defects such as gas defects, and stabilizing high quality cast products. It is possible to obtain.

Further, according to the cylinder head casting method of the tenth aspect of the present invention, since the cooling means is provided on each of the projections for forming the holes provided in the upper mold, the mold farther from the gate is provided. It is possible to give directionality to cooling of the molten metal after the casting step so that the (upper mold) is actively cooled so that the molten metal solidifies from a portion as far as possible to the gate. Also,
As for the cooling means provided on the plurality of protrusions, the cooling capacity of the inner protrusion relatively close to the center of the mold is set to be larger than that of the outer protrusion relatively close to the periphery of the mold, so that the casting cavity The central portion and the outer portion can also be cooled with directivity such that the molten metal is gradually cooled from the central portion as much as possible. That is, when solidifying the molten metal after casting, the provision of the cooling means not only promotes the solidification of the molten metal but also enhances the solidification speed, and also utilizes the shape peculiar to the cylinder head to obtain appropriate directivity. Can be made to perform cooling with
It is possible to effectively suppress the occurrence of defects such as gas defects and more stably obtain a high-quality cast product.

Further, according to the cylinder head casting method of the eleventh aspect of the present invention, heat propagation in a direction other than a predetermined direction is suppressed in at least one of the upper mold and the lower mold. Since the set spot cooling means is provided, a specific portion of the molten metal in the mold cavity can be cooled and solidified with directivity in a predetermined direction, thereby effectively suppressing the occurrence of defects such as gas defects. As a result, a high-quality cast product can be obtained more stably.

Further, according to the cylinder head casting method of the twelfth aspect of the present invention, cooling means is provided on each of the projections for forming holes in the upper die on the upper die side. Therefore, it is possible to provide directivity to the cooling of the molten metal after the casting process so that the metal mold (upper mold) on the side far from the gate is actively cooled and the molten metal solidifies from the part as far as possible to the gate. Become. Further, as for the cooling means provided on the plurality of protrusions, the cooling ability of the inner protrusion relatively closer to the center of the mold is set to be larger than that of the outer protrusion relatively closer to the periphery of the mold. With respect to the central portion and the outer portion of the casting cavity, the molten metal can be cooled with directivity such that the molten metal is gradually cooled from the central portion as much as possible. On the other hand, the lower mold side is provided with a spot cooling means set to suppress heat propagation in directions other than the predetermined direction,
A specific portion of the molten metal in the mold cavity can be cooled and solidified with directivity in a predetermined direction from the lower mold side. That is, when solidifying the molten metal after casting, the provision of the respective cooling means not only promotes the solidification of the molten metal but also enhances the solidification speed, and also utilizes the shape unique to the cylinder head to achieve appropriate orientation. It is possible to perform cooling with a characteristic, and it is possible to effectively suppress the occurrence of defects such as gas defects and to more stably obtain a high-quality cast product.

[Brief description of the drawings]

FIG. 1 is a front explanatory view schematically showing an example of a casting apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory side view of the casting apparatus.

FIG. 3 is an explanatory longitudinal sectional view of a holding furnace and a mold schematically showing an internal structure of the holding furnace of the casting apparatus.

FIG. 4 is a block diagram schematically showing a pressure control system of the casting apparatus.

FIG. 5 is an explanatory bottom view of an upper die of the casting apparatus.

FIG. 6 is an explanatory plan view of a lower die of the casting apparatus.

FIG. 7 is an explanatory plan view showing the lower die port core set state;

FIG. 8 is an explanatory longitudinal sectional view showing a state in which a core is set on the lower die.

FIG. 9 is a view from arrow Y9-Y9 of FIG. 8;

FIG. 10A is an explanatory vertical sectional view of an upper die and a side die showing a side-type slide guide mechanism. (B)
It is an arrow view from the Y10B-Y10B direction of FIG.10 (a).

FIG. 11 is a partial longitudinal sectional view showing a state where the water jacket core and the oil jacket core are set in a lower mold.

FIG. 12 is an enlarged plan view showing an engagement portion between the lower die and the baseboard of the water jacket core.

FIG. 13 is an explanatory longitudinal sectional view taken along line Y13-Y13 of FIG. 12;

FIG. 14 is an enlarged vertical cross-sectional explanatory view of a core supporting portion showing a degassing mechanism of the mold.

FIG. 15 is an explanatory longitudinal sectional view of a mold showing a combination state of the upper mold and the lower mold.

FIG. 16 is an enlarged longitudinal sectional view showing a plug hole forming portion of the upper die.

FIG. 17 is an explanatory longitudinal sectional view showing a bolt hole forming portion of the upper die in an enlarged manner.

FIG. 18 is an explanatory longitudinal sectional view showing the spot cooling mechanism of the lower die in an enlarged manner.

FIG. 19 is a second bogie (core bogie) according to the present embodiment.
FIG.

FIG. 20 is an explanatory diagram showing an enlarged vertical drive portion of the application box of the second carriage.

FIG. 21 is an explanatory plan view of a cover member mounted on the second carriage.

FIG. 22 is an explanatory longitudinal sectional view showing a relationship among a mold, a cover member, a spray nozzle, and a blow nozzle.

FIG. 23 is a cross-sectional top view showing a spray nozzle, a blow nozzle, and a spray nozzle driving portion arranged in a cover member.

FIG. 24 is an explanatory plan view of a spray nozzle.

FIG. 25 is an explanatory longitudinal sectional view taken along line Y25-Y25 in FIG. 24;

FIG. 26 is a system diagram of a spray nozzle, a blow nozzle, and a suction port.

FIG. 27 is a time chart showing the relationship between the movement of a spray nozzle, the spraying of a powder coating agent, the blowing and blowing of blow air, and the supply of purge air.

FIG. 28 is an explanatory side view of a driving mechanism of the core holding claw of the core setting device.

FIG. 29 is an explanatory front view of a driving mechanism of the core holding claw.

FIG. 30 is a schematic diagram for explaining the operation of the driving mechanism of the core holding claw.

FIG. 31 is a schematic diagram for explaining an operation of a driving mechanism of a core holding claw according to a conventional example.

FIG. 32 is a schematic diagram for explaining an operation of a driving mechanism of a core holding claw according to another conventional example.

FIG. 33 is a flowchart showing a casting process using the low-pressure casting apparatus.

FIG. 34 is a flowchart showing a core setting step and a mold applying agent applying step in relation to the operation of the core carrier.

FIG. 35 is a flowchart showing a pressurization control method in the low-pressure casting apparatus.

FIG. 36 is a pressure pattern diagram showing a pressure control method in the low-pressure casting device.

FIG. 37 is a pressure pattern diagram showing a specific pressure control method of the low-pressure casting device.

FIG. 38 is a pressure pattern diagram showing a modification of the pressure control method of the low-pressure casting device.

[Description of Signs] 9 ... Distributor 105 ... Recessed Space 106 ... Communication Tube 111 ... Plug Hole Forming Projection 112 ... Bolt Hole Forming Projection 114 ... Introduction Pipe (Plug Hole Forming Projection) 115 ... Discharge Pipe (Plug hole forming protrusion) 116 ... Introduction pipe (bolt hole formation protrusion) 138 ... Sand wall 151 ... Spot cooling mechanism 152 ... Body part 152h ... Cooling medium passage 153 ... Supply pipe 154 ... Discharge pipe 156 ... Mounting hole A ... Casting device D ... Mold Di ... Gate DL ... Lower mold DS (DS1, DS2, DS3) ... Side mold DU ... Upper mold Mc ... Cast cavity

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B22D 27/04 B22D 27/04 F F02F 1/24 F02F 1/24 B

Claims (12)

[Claims] 1. A casting mold formed between a pair of upper and lower molds provided so as to be able to contact and separate from each other, and a molten metal is injected and filled from a sprue provided in the lower mold to fill the casting cavity. What is claimed is: 1. A casting apparatus for solidifying a cylinder head of an engine by solidifying, wherein a plurality of protrusions for forming a hole are provided on the upper die, and cooling means are provided on each of the protrusions. A casting apparatus for a cylinder head, wherein a cooling capacity of an inner protrusion relatively close to the center of the mold is set to be larger than that of an outer protrusion relatively close to the periphery of the mold. 2. The cylinder according to claim 1, wherein the cooling medium of the cooling means provided on the inner projection is liquid, and the cooling medium of the cooling means provided on the outer projection is gas. Head casting equipment. 3. The cylinder head according to claim 2, further comprising an exclusion unit that eliminates a cooling medium remaining in the projection after the cooling operation of the cooling unit provided on the inner projection is stopped. Casting equipment. 4. A projection according to claim 1, wherein said projection corresponds to at least a plug hole relatively close to the center of the cylinder head and a bolt hole relatively close to the periphery of the cylinder head. The casting apparatus for a cylinder head according to any one of the above. 5. A mold comprising a pair of upper and lower dies and a side wall provided so as to be able to contact and separate from each other, and injecting molten metal into a casting cavity formed by the both dies and the side wall from a gate provided in the lower die. A casting device for filling and solidifying the molten metal to cast a cylinder head of an engine, wherein heat propagation in a direction other than a predetermined direction is suppressed to at least one of the upper mold and the lower mold. An apparatus for casting a cylinder head, comprising a spot cooling means set as described above. 6. The spot cooling means is provided by providing a cooling medium passage in a cylindrical member, and the cylindrical member has an end surface facing the casting cavity and an outer peripheral portion provided in a mold. The cylinder head casting apparatus according to claim 5, wherein the cylinder head is fitted in the hole. 7. The cylinder head casting apparatus according to claim 5, wherein a part of the side wall is formed of a sand wall, and the spot cooling means is provided near the sand wall. . 8. A lower part of the lower mold is provided with a molten metal supply section for supplying molten metal injected into the casting cavity through the gate, and a predetermined space is provided between the molten metal supply section and the lower mold. Wherein a cooling medium path for the spot cooling means is disposed in the space, and a communication path for communicating the molten metal supply section with the gate is formed. 8. The cylinder head casting apparatus according to any one of items 7 to 7. 9. A molten metal is provided from a gate provided in the lower mold into a casting cavity formed by the pair of upper mold and lower mold and a side wall which are provided so as to be able to contact and separate from each other. A casting apparatus in which a cylinder head of an engine is cast by filling and solidifying the molten metal, wherein a plurality of protrusions for forming a hole are provided on the upper die, and cooling means is provided on each protrusion. In these cooling means, the cooling ability of the inner protrusion relatively close to the center of the mold is set to be larger than that of the outer protrusion relatively close to the periphery of the mold. An apparatus for casting a cylinder head, comprising a spot cooling means set so as to suppress heat propagation in a direction other than a predetermined direction. 10. A molten metal is injected and filled into a casting cavity formed between a pair of upper and lower molds provided so as to be able to contact and separate from each other from a gate provided in the lower mold, and the molten metal is solidified. A casting method for casting a cylinder head, wherein a plurality of protrusions for forming a hole are provided in the upper die,
Cooling means are provided for each of the protrusions, and the cooling capacity of these cooling means is set so that the inner protrusion relatively closer to the center of the mold is larger than the outer protrusion relatively closer to the periphery of the mold. A method for casting a cylinder head. 11. A molten metal is poured and filled into a casting cavity formed by a pair of upper and lower dies and a side wall provided so as to be able to contact and separate from a gate provided in the lower die to solidify the molten metal. A casting method for casting a cylinder head of an engine, wherein at least one of the upper mold and the lower mold is provided with a spot cooling means set so that heat propagation in a direction other than a predetermined direction is suppressed. A method for casting a cylinder head. 12. A molten metal is injected and filled into a casting cavity formed by a pair of upper and lower molds and a side wall provided so as to be able to be separated from each other and from a gate provided in the lower mold to solidify the molten metal. A casting method for casting a cylinder head of an engine, wherein a plurality of protrusions for forming a hole are provided in the upper die,
Cooling means are provided for each of the protrusions, and the cooling capacity of these cooling means is set so that the inner protrusion relatively closer to the center of the mold is larger than the outer protrusion relatively closer to the periphery of the mold. On the other hand, a method of casting a cylinder head, characterized in that the lower mold is provided with spot cooling means set so as to suppress heat propagation in directions other than a predetermined direction.