JP5563438B2 - Cylinder head casting mold cooling apparatus and control method thereof - Google Patents

Description

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

  When manufacturing a cylinder head of an engine, a low pressure casting method is widely used. In this low pressure casting method, as is well known, the surface of the molten metal is heated with a relatively low pressure gas while the molten metal is heated and held. In this method, the mold is filled with molten metal by pressurization.

  By the way, in the cylinder head, the combustion chamber, particularly its top wall and its periphery, are required to have a strength that can withstand high temperature and high pressure.

  In response to the above requirements, in the conventional mold, as shown in FIG. 13, a cooling water passage 201 is formed inside the lower mold combustion chamber insert 200, and the combustion chamber insert 200 is cooled at a desired timing. By forcibly and locally cooling, the solidification of the molten metal forming the top wall of the combustion chamber is promoted and the strength of the top wall of the combustion chamber is increased (Patent Document 1).

Japanese Patent No. 363618

  In the prior art shown in FIG. 13, the cooling water supply pipe 210 and the cooling water discharge pipe 211 connected to the inlet and outlet of the cooling water passage 201 of the combustion chamber insert 200 are both on the combustion chamber insert 200. Is connected to the side (right side of the figure) and largely bypasses the cylinder head cavity to the edge of the other side of the lower mold (left side of the figure), and the pipes 210 and 211 are arranged so as to extend substantially in parallel with each other. It is installed.

  Thus, when the cooling water supply pipe 210 and the cooling water discharge pipe 211 are arranged, in order to avoid interference with other parts of the mold, for example, a slide-type rail or a gate forming member 212, the pipe The degree of freedom of layout is greatly limited, and the mold manufacturing is complicated.

  A cooling water supply pipe 210 through which low-temperature cooling water before use circulates and a cooling water discharge pipe 211 through which high-temperature cooling water after use circulates are arranged in parallel with each other. If so, heat exchange is performed directly between the pipes 210 and 211, and the cooling performance of the combustion chamber insert 200 is reduced.

  The present invention improves the strength of the combustion chamber of the cylinder head to be manufactured by forcibly and locally cooling the combustion chamber forming portion such as the combustion chamber insert, and also provides a coolant supply passage and a coolant. An object of the present invention is to provide a cylinder head casting die cooling device and a control method thereof, which can increase the degree of freedom in designing the layout of the discharge passage, facilitate the manufacture of the die, and maintain the strength of the lower die. Yes.

In order to solve the above-described problems, a cooling apparatus for a cylinder head casting mold according to the present invention includes the following structural requirement (a).
(A) A combustion chamber forming portion that includes at least a lower mold for forming the lower surface of the cylinder head and an upper mold for forming the upper surface of the cylinder head, and forms a top wall of the combustion chamber of the cylinder head in the lower mold. In the cylinder head casting die cooling apparatus, a cooling fluid passage is formed in the combustion chamber forming portion, and a cooling fluid supply passage and a cooling fluid discharge passage are provided at an inlet and an outlet of the cooling fluid passage. The cooling liquid supply passage and the cooling liquid discharge passage are respectively connected to the lower mold portion on one side and the other side so that cooling water flows from one side to the other side with respect to the combustion chamber forming portion. And a pair of opposed slide molds that form an outer peripheral side wall surface of the cylinder head, and the coolant supply passage and the coolant discharge passage are provided as one of the slide molds. Placement When are arranged divided into a placement side of the other of the sliding side.

The present invention can include the following structural requirements (b) to (f) in addition to the structural requirement (a) .

(B) The cooling liquid supply passage and the cooling liquid discharge passage are respectively configured by a cooling liquid supply pipe and a cooling liquid discharge pipe, and the cooling liquid supply pipe and the cooling liquid discharge pipe are formed in the lower mold. The tunnel-shaped passage is disposed with an annular space portion therebetween.

(C) A plurality of the combustion chamber forming portions are arranged in a substantially straight line, and the pair of slide molds are arranged on the one side and the other side with respect to the line of the straight combustion chamber forming portions. ing.

(D) The coolant supply passage and the coolant discharge passage are arranged substantially in a straight line.

(E) The combustion chamber forming portion is formed by a combustion chamber insert, and the coolant passage in the combustion chamber insert is formed in a substantially V shape.

(F) The combustion chamber forming portion is formed by a combustion chamber insert, a small diameter portion is formed on the outer peripheral surface of the combustion chamber insert through a step portion, and an annular shape is formed on the outer periphery of all the small diameter portions. An air layer is formed. In this case, preferably, the coolant supply passage and the coolant discharge passage are respectively connected to an inlet and an outlet of the combustion chamber insert, and a leakage discharge passage is formed below the combustion chamber insert. Has been.

  The present invention also provides a method for controlling the cooling device for the cylinder head casting mold, after supplying the coolant to the coolant passage for the spark plug insertion hole forming portion after pouring hot water, Coolant is supplied to the coolant passage of the chamber forming section.

(1) According to the present invention having the above-described structural requirement (a) , the molten metal solidifies by forcibly and locally cooling the top wall of the combustion chamber with cooling water at a predetermined timing during casting. And the strength of the combustion chamber top wall of the cylinder head can be improved.

(2) Since the coolant supply passage and the coolant discharge passage are arranged separately on one side and the other side of the combustion chamber molding portion, the degree of freedom in designing the layout of both passages is increased, and the mold is manufactured. Easy to do. In addition, the strength of the lower mold can be maintained.

(3) Since the coolant supply passage and the coolant discharge passage are separated corresponding to the arrangement of the pair of opposed slide molds, external piping connected to the coolant supply passage and the coolant discharge passage, Easy to do. In particular, by arranging so as not to interfere with the slide-type rail, both passages can be compactly arranged while maintaining the slide-type operability.

(4) As in the configuration (b), by using a coolant supply pipe and a coolant discharge pipe as the coolant passage, and by providing an annular space on the outer periphery of each pipe, The heat of the water is cut off, the coolant is prevented from becoming high temperature, and the cooling efficiency is improved.

(5) As in the configuration (c), by arranging a pair of slide dies on the one side and the other side with respect to the row of combustion chamber forming portions arranged in a straight line, a plurality of inline dies are arranged. When the cylinder head for the cylinder is formed, the degree of freedom in the layout of the coolant passage becomes higher, and each cylinder can be cooled uniformly.

(6) Since the coolant supply passage and the coolant discharge passage are arranged substantially in a straight line as in the configuration (d), the layout of the coolant passage can be simplified, and the manufacturing is facilitated. Thus, the flow resistance of the coolant is reduced, and a rapid flow of the coolant can be maintained.

(7) As in the configuration (e), a substantially V-shaped cooling water passage is formed in the combustion chamber nest so that the coolant passage is simply formed by drilling in a straight line. It can be formed and the coolant passage is easy to process.

(8) When the annular air layer is formed by forming a small-diameter portion on the outer peripheral surface of the combustion chamber insert as in the configuration (f), an annular space is formed between the combustion chamber insert and the lower mold. Insulate with an air layer to promote cooling in the combustion chamber insert. Moreover, the liquid leakage can be quickly discharged. In this case, by forming a leakage discharge passage below the combustion chamber nest, the coolant leaked at the connection between the combustion chamber nest and the coolant supply pipe and the coolant discharge pipe Can be discharged.

(9) In the cylinder head casting mold, hot water is poured from the lower mold and solidifies from the upper end, so that the upper spark plug insertion hole forming section and the upper mold are formed in order from the upper side as in the control method according to the present invention. By locally cooling the lower-chamber combustion chamber forming part, each part can be appropriately cooled according to the solidified state.

It is a top view of the lower mold of the cylinder head casting mold concerning the present invention. FIG. 8 is a cross-sectional front view of the mold of FIG. 1 (a cross-sectional view substantially corresponding to a cross section taken along line II-II in FIG. 7). It is a rear view of the metal mold | die of FIG. It is a top view of the upper mold | type of the metal mold | die of FIG. It is a top view of the combustion chamber nest | insert of the metal mold | die of FIG. FIG. 6 is a front view of FIG. 5. It is the VII-VII sectional view taken on the line of FIG. 1 which abbreviate | omits and shows a part of metal mold | die. It is an expanded sectional view of a part of FIG. It is the IX-IX sectional view enlarged view of FIG. FIG. 3 is an enlarged cross-sectional view of the gate sleeve of FIG. 1 taken along the line XX. It is a top view of the gate gate of FIG. It is an example of the time chart which shows control of the hot water and cooling water in a casting process. It is a top view of a prior art example.

  1 to 12 show a die for casting a cylinder head of a low-pressure casting system according to the present invention for producing a cylinder head of an in-line type four-cylinder engine. Based on these drawings, FIG. An embodiment of the present invention will be described.

[Configuration of the entire mold]
1 is a plan view of the lower mold of the mold, FIG. 2 is a longitudinal sectional view of the mold, FIG. 3 is a rear view of the mold (viewed along arrow III in FIG. 1), and FIG. 7 is a part of the mold. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 1, omitted for convenience of explanation, where the alignment direction of the four cylinders of the engine (the crankshaft direction of the engine) is the “left-right direction” of the mold; The “side” will be referred to as the “front” of the mold and will be described below.

  In FIG. 2, the mold includes a lower mold 1 for molding the lower surface of the cylinder head (cavity portion in the figure), an upper mold 2 for molding the upper surface of the cylinder head, and an outer peripheral side surface of the cylinder head. A pair of left and right slide molds 5 and 6 for forming the left and right side surfaces, and a pair of front and rear slide molds 3 and 4 (FIG. 7) for forming the front and rear surfaces of the cylinder head are provided.

  A lower mold 1 shown in FIG. 2 includes a lower mold main mold 11, a lower mold insert spacer 13 disposed in a recess 12 formed on the upper surface of the lower mold main mold 11, and the lower mold insert spacer 13. The lower mold insert 14 fixed to the upper surface of the lower mold insert, four combustion chamber inserts (combustion chamber forming portions) 16 provided in the lower mold insert 14, and a plurality of gates (only one is shown in FIG. 2) ) And a gate sleeve 18 for forming 17. The combustion chamber insert 16 is substantially used only as a molding surface for forming the top wall of the combustion chamber.

  The upper die 2 is provided with four spark plug insertion hole molding inserts (or projections) 22 so as to protrude downward, and for forming an upper portion of the coolant jacket, bolt insertion holes and other hollow portions. Various inserts 23 (or projections) are provided. A cooling air passage 25 is formed in the upper mold 2.

  In addition to the lower mold 1 and the upper mold 2, the mold is further provided with a sand core 26 (indicated by a hit point) for forming various hollow portions (particularly the lower portion) such as a coolant jacket. ing.

  In FIG. 1, the gate 17 is provided between the first cylinder combustion chamber insert 16 on the left end and the second cylinder combustion chamber insert 16 on the second end from the left end, and on the third cylinder combustion on the third end from the left end. A pair of front and rear is arranged between the chamber insert 16 and the fourth fourth cylinder combustion chamber insert 16. Rails 31 and 32 for slidably supporting the front and rear and left and right slide molds 3, 4, 5, and 6 (see FIGS. 2 and 7) are provided on the four sides of the upper surface of the lower mold main mold 11. Three of each are laid.

  In FIG. 3, three sliders 35 are fixed to the lower end surface of the rear slide mold 4 at intervals in the left-right direction, and each slider 35 is movable in the front-rear direction on the three rear rails 31. It is supported by. In addition, side sliders 38 that are fitted to guide rails 37 laid on the side support wall 36 so as to be movable in the front-rear direction are provided on the left and right sides of the rear slide mold 4. The front slide mold 3 in FIG. 7 and the left and right slide molds 5 and 6 in FIG. 2 have the same slide structure as the rear slide mold 4.

  FIG. 5 is a plan view of the combustion chamber insert 16, and FIG. 6 is a front view of the combustion chamber insert 16. In FIG. 5, a pair of left and right intake port molding projections 33 are formed on the front side of the upper surface (top wall molding surface) 16a of the combustion chamber insert 16, and a pair of left and right exhaust port molding projections 34 are formed on the rear side. Is formed.

  In FIG. 6, connecting portions 16b protruding left and right are integrally formed at the lower end portion of the combustion chamber insert 16, and the connecting portions 16b are connected together by bolts (not shown). Four combustion chamber inserts 16 are connected in a line on the left and right. Further, the gate sleeve 18 (FIG. 5) is provided on the opposing surfaces of the combustion chamber inserts 16 for the first and second cylinders and the opposing surfaces of the combustion chamber inserts 16 for the third and fourth cylinders. In order to arrange the two, a pair of front and rear arc-shaped cutouts 40 are formed.

  10 is a cross-sectional view of the gate sleeve 18 taken along the line XX of FIG. 1, and FIG. 11 is a plan view. As shown in FIG. 10, each gate 17 has a truncated conical shape with a diameter decreasing upward, and the gate sleeve 18 includes four gates 17 that constitute the four gates 17 as shown in FIG. 11. A cylindrical portion 18a is integrally provided. A pair of left and right cooling air passage forming members 19 are fixed to the base plate portion 18b of the gate sleeve 18 by welding. Each cooling air passage forming member 19 is formed in an oval shape long in the front-rear direction so as to surround a pair of gates 17 facing in the front-rear direction. Thus, a gate cooling air passage 42 is formed that circulates around the front and rear gates 17 in an oval shape.

  In the mold having such a configuration, in addition to an air-cooling type cooling device that cools the gate 17 and the upper mold 2 with cooling air, each combustion chamber insert 16 of the lower mold 1 is forcibly and locally cooled with cooling water. And a water cooling type cooling device that forcibly and locally cools each spark plug insertion hole molding insert 22 of the upper mold 2 with cooling water.

[Water-cooled cooling device for combustion chamber insert 16]
A water-cooled cooling device for the combustion chamber insert 16 will be described with reference to FIG. 7, FIG. 8 which is an enlarged longitudinal sectional view of the combustion chamber insert shown in FIG. 7, and FIG. To do. In FIG. 8, each combustion chamber insert 16 has an inverted V-shaped cooling water passage 53 extending from a cooling water inlet 51 formed at the lower portion of the rear end surface to a cooling water outlet 52 formed at the lower portion of the front end surface. Is formed. The cooling water passage 53 includes a first passage portion 53a that extends substantially horizontally forward from the rear end inlet 51 in a substantially straight line, and a first linear portion that extends substantially frontward and upward from the front end portion of the first passage portion 53a. Two passage portions 53b, a third passage portion 53c extending substantially linearly downward from the upper end of the second passage portion 53b, and substantially horizontally forward from the lower end of the third passage portion 53c. The fourth passage portion 53 d extends to the cooling water outlet 52. The four passage portions 53a, 53b, 53c, 53d are all formed by drilling. In particular, the second and third passage portions 53b, 53c are drilled from the lower surface of the combustion chamber insert 16. At the same time, plug screws 55 are respectively screwed into the lower end portions and sealed by welding. The first passage portion 53a and the fourth passage portion 53d are respectively drilled from the rear end surface and the front end surface of the combustion chamber insert 16, and female threads are respectively formed on the inner peripheral surfaces of the rear end inlet 51 and the front end outlet 52. Is formed.

  The front end tapered male threaded portion of the cooling water supply pipe 61 is screwed into the rear end inlet 51 portion of the first passage portion 53a, and the joint surface is sealed by welding V1. The rear end taper male thread portion of the cooling water discharge pipe 62 is screwed to the front end outlet 52 of the fourth passage portion 53d, and the joint surface is sealed by welding V1.

  A small-diameter portion 16c is formed on the outer peripheral side wall of the combustion chamber insert 16 via a step portion, and this small-diameter portion 16c extends from the upper portion of the combustion chamber insert 16 to the lower end edge. An annular air layer S1 is formed between the inner peripheral surface of the combustion chamber insert mounting hole 14a formed in the outer peripheral surface 14 and the outer peripheral surface of the small diameter portion 16c. This annular air layer S1 also has a water leakage discharge function to be described later.

  In FIG. 7, the cooling water supply pipe 61 connected to the rear end inlet 51 of the combustion chamber insert 16 is substantially straight rearward in a substantially straight tunnel 63 formed in the rear half of the lower mold insert 14. To the rear edge of the mold and connected to a cooling water pump (not shown). A cooling water discharge pipe 62 connected to the front end outlet 52 of the combustion chamber insert 16 extends substantially straight forward in a substantially straight tunnel 63 formed in the front half of the lower mold insert 14. And communicates with a water storage section or an external drainage section through a drainage hose (not shown).

  In FIG. 9, the cross section of the tunnel 63 of the lower mold insert 14 is formed in a lower end opening shape, and the upper end portion has an arc shape facing the outer peripheral surface of the cooling water supply pipe 61 via the space portion S <b> 2. In addition, the left and right side surfaces of the tunnel 63 reach the lower end edge of the lower mold insert 14 in a substantially straight line. That is, at least an annular space (air layer) S2 is formed on the outer peripheral surface of the cooling water supply pipe 61, and the cooling water supply pipe 61 can be taken in and out of the lower mold insert 14 from below. The front-side tunnel 63 in which the cooling water discharge pipe 62 shown in FIG. 7 is arranged also includes a space S2 on the outer peripheral surface of the cooling water discharge pipe 62 as in FIG.

  In FIG. 1, four cooling water discharge pipes 62 for each cylinder are arranged so as to extend forward from each combustion chamber nest 16 in a state avoiding interference with the three rails 31 for the front slide type. Has been. Further, the four cooling water supply pipes 61 for each cylinder are arranged so as to extend rearward from the respective combustion chamber inserts 16 while avoiding interference with the three rails 31 for the rear slide type. ing.

  Specifically, the cooling water supply pipe 61 and the cooling water discharge pipe 62 for the second cylinder, which is the second cylinder from the left end, are substantially orthogonal to a reference line C1 that connects the centers of the combustion chamber inserts 16 and extends in the left-right direction. Are arranged on a straight line M. Thereby, the cooling water supply pipe 61 and the cooling water discharge pipe 62 for the second cylinder second from the left end are arranged between the left end rail 31 for the rear slide type and the central rail 31 and the left end for the front slide type. The rail 31 and the central rail 31 are passed in parallel with the rails 31.

  The cooling water supply pipe 61 for the first cylinder at the left end is inclined with respect to the straight line M substantially perpendicular to the reference line C1 so as to come to the left as it goes backward in plan view. Is set to 12 °, for example. The cooling water discharge pipe 62 for the first cylinder is inclined with respect to the straight line M substantially orthogonal to the reference line C1 so as to come to the left as it goes forward in plan view. The angle θ1 is set to 12 °. With this arrangement, the cooling water supply pipe 61 and the cooling water discharge pipe 62 for the first cylinder at the left end both pass through the left side of the left end rail 31 for each of the front and rear slide types.

  The third third-cylinder cooling water supply pipe 61 and the fourth fourth-cylinder cooling water supply pipe 61 from the left end are rearward in a plan view with respect to a straight line M substantially orthogonal to the reference line C1. As it goes, it is inclined to the right and left, and the inclination angles θ3 and θ4 with respect to the straight line M are set to 3 ° and 5 °. Accordingly, the cooling water supply pipes 61 for the third cylinder and the fourth cylinder pass between the rear slide type center rail 31 and the right end rail 31. The cooling water discharge 62 for the third cylinder and the cooling water discharge pipe 62 for the fourth cylinder are respectively rightward and leftward as viewed from above in a plan view with respect to the straight line M substantially perpendicular to the reference line C1. The inclination angles θ3 and θ4 with respect to the straight line M are set to 3 ° and 5 °. Accordingly, the coolant discharge pipes 62 for the third cylinder and the fourth cylinder pass between the center rail 31 and the right end rail 31 for the front slide type.

  In FIG. 2, a water leakage receiving groove 66 is formed on the upper surface of the lower mold insertion spacer 13 over the entire combustion chamber insertion 16, and the water leakage receiving groove 66 has a dish-like shape that can be extracted from the left end. A water leakage receiving plate 67 is inserted. 7 and 8, the water leakage receiving plate 67 has a width including a region corresponding to the outer peripheral surface of the combustion chamber insert 16, and is a connecting portion between the cooling water supply pipe 61 and the rear end inlet 51. In addition, the cooling water leaking from the connection portion between the cooling water discharge pipe 62 and the front end outlet 52 is received, flows to the left, and is discharged from the left end to the outside of the mold.

[Cooling device for spark plug insertion hole forming section]
In FIG. 2, a cooling water pipe 70 having a double wall structure is inserted into each spark plug insertion hole molding insert 22, and an inner passage of the cooling water pipe 70 serves as a cooling water supply passage 70a. The passage is a cooling water discharge passage 70b.

  A cooling water supply pipe 72 is connected to an upper end portion of the inner cooling water supply passage, and a cooling water discharge pipe 73 disposed below the cooling water supply pipe 72 is connected to the outer cooling water discharge passage. Yes.

  In FIG. 4, each of the cooling water supply pipes 72 extends rearward in a U-shape and is collected to the center side of the left and right width of the upper mold 2, and via the cooling water supply passage 76 in the branching and collecting block 75. The cooling water supply source pipe 77 is connected to a cooling water pump or the like.

  In FIG. 3, each of the four cooling water discharge pipes 73 is also connected to an external cooling water discharge section via a cooling water discharge collecting passage 78 in the branching and collecting block 75, similarly to the cooling water supply pipe 72. It is connected to the.

[Casting work]
(1) The lower mold main mold 11 shown in FIG. 2 is attached to a fixed plate 80 on a crucible (not shown) in which a molten metal (melted metal) such as an aluminum alloy is stored, and the upper mold 2 is a cylinder (FIG. The slide molds 3 and 4 (see FIG. 7) and the slide molds 5 and 6 are horizontally moved actuators (not shown). ).

(2) The crucible with the lower mold 1, the upper mold 2, the slide molds 3 and 4 (see FIG. 7) and the slide molds 5 and 6 being set at predetermined positions and with various sand cores 26 and the like attached. Compressed air is injected into the inside, whereby the molten metal is pushed up, passes through the four gates 17 and is injected into a cavity (not shown) of the mold.

(3) The molten metal filled in the cavity is solidified by being cooled for a predetermined time while being pressurized at a low pressure. And the cylinder head which is a product is taken out by opening a mold.

(4) In the cooling period, first, the spark plug insertion hole molding insert 22 disposed above is forcibly and locally cooled by the cooling water flowing through the cooling water pipe 70, and subsequently disposed at the lower end. The combustion chamber insert 16 is forcibly and locally cooled by the cooling water flowing through the cooling water passage 53 (FIG. 7) in the combustion chamber insert 16.

  FIG. 12 is a time chart of the casting process, where t0 is the start of pressurization after filling the molten metal, t1 is the start of cooling of the spark plug insertion hole molding insert 22, and t2 is the cooling of the spark plug insertion hole molding insert 22. At the end, t3 indicates the start of cooling of the combustion chamber insert 16, t4 indicates the end of cooling of the combustion chamber insert 16, t5 indicates the end of pressurization, t6 indicates the start of solidification, and t7 indicates the end of solidification. Yes. In FIG. 12, after about 10 seconds have elapsed from the start of pressurization (t0), cooling of the spark plug insertion hole molding insert 22 is first started (t1), and after about 60 seconds have elapsed, cooling is stopped (t2). At the same time, cooling of the combustion chamber insert 16 is started (t3), and after about 60 seconds, cooling is stopped (t4). Thereafter, after a few seconds, the pressure is released (t5).

(5) In the cooling step (t1t2) of the spark plug insertion hole forming insert 22, as shown in FIG. 4, the cooling water supplied from the rear cooling water supply source pipe 77 is the cooling water supply pipe 72 for each cylinder. And are sent to the cooling water pipe 70 for each cylinder. In FIG. 2, the spark plug insertion hole insert 22 is forcibly and locally moved by moving downward through the inner passage of the cooling water pipe 70 having a double wall structure and returning upward through the outer passage. Then, it is cooled and then discharged to the cooling water discharge pipe 73.

(6) In the cooling step (t3t4) of the combustion chamber forming insert 16, as shown in FIG. 1, the cooling water is burned from the cooling water supply pipes 61 for the respective cylinders arranged in the rear half of the lower mold 1. After being supplied into the chamber insert 16 and passing through the inverted V-shaped cooling water passage 53 in the combustion chamber insert 16 as shown in FIG. 7, the combustion chamber insert 16 is cooled and then placed in the first half of the lower mold 1. The refrigerant is discharged through the arranged coolant discharge pipe 62 for each cylinder.

  In FIG. 8, in the combustion chamber insert 16, first, it flows into the substantially horizontal first passage portion 53a from the rear end inlet 51, and then flows forward and upward in the second passage portion 53b. Folded from the upper end portion of the passage portion 53b and flows forward and downward through the third passage portion 53c, and then flows forward from the lower end portion of the third passage portion 53c through the fourth passage portion 53d and from the front end outlet 52 to the coolant. It is discharged to the discharge pipe 62.

  During the cooling of the combustion chamber insert 16, cooling water may leak from the connection between the cooling water supply pipe 61 and the rear end inlet 51 and the connection between the cooling water discharge pipe 62 and the front end outlet 52. 2 passes through the annular air layer S1 formed on the outer periphery of the small-diameter portion 16c of the combustion chamber insert 16 and is collected in the lower water leakage receiving plate 67 and flows to the left through the water leakage receiving plate 67 as shown in FIG. It is discharged from the part to the outside of the mold.

(7) The gates 17 of the upper mold 2 and the lower mold 1 are constantly cooled during casting by the cooling air supplied to the cooling air passage 25 (FIG. 2) and the cooling air passage 42 (FIG. 10). .

[Effects of the embodiment]
(1) In FIGS. 7 and 8, by supplying cooling water to the cooling water passage 53 formed in the combustion chamber insert 16, the combustion chamber insert 16 is forcibly and locally cooled. Solidification of the molten metal on the combustion chamber top wall can be promoted, and the strength of the combustion chamber top wall of the cylinder head can be improved.

(2) Since the cooling water passage 53 of the combustion chamber insert 16 is formed in an inverted V shape, it can be formed simply by drilling in a substantially straight line with a drill.

(3) The cooling water supply pipe 61 for cooling the combustion chamber nest is disposed on the rear side with respect to the combustion chamber nest 16, the cooling water discharge pipe 62 is disposed on the front side with respect to the combustion chamber nest 16, Since cooling water flows from the rear side to the front side of the combustion chamber insert 16, the degree of freedom in designing the layout of the cooling water supply pipe 61 and the cooling water discharge pipe 62 is increased, and the mold can be easily manufactured. In addition, the strength of the lower mold 1 can be maintained.

(4) Since the cooling water supply pipe 61 and the cooling water discharge pipe 62 for the combustion chamber insert 16 are separated corresponding to the arrangement of the opposed rear slide mold 4 and front slide mold 3, the cooling water supply An external pipe or the like connected to the pipe 61 and the cooling water discharge pipe 62 is easily attached. In particular, by arranging the cooling water discharge pipe 62 and the cooling water supply pipe 61 so as not to interfere with the rails 31 (FIG. 1) of the front and rear slide molds 3 and 4, the operability of the slide molds 3 and 4 is maintained. Meanwhile, the cooling water supply pipe 61 and the cooling water discharge pipe 62 can be arranged in a compact manner.

(5) Since the annular space S2 is provided between the outer peripheral surface of the cooling water supply pipe 61 and the inner peripheral surface of the tunnel 63 of the lower mold insert 14 as shown in FIG. It is possible to block the heat from the child 14 and prevent the cooling water from becoming high temperature. Thereby, cooling efficiency improves.

(6) When casting a cylinder head for an in-line type multiple cylinder engine as shown in FIG. 1, a plurality of combustion chamber inserts 16 are juxtaposed on the same reference line C1 extending left and right, as shown in FIG. In addition, the slide molds 3 and 4 are arranged before and after the combustion chamber insert 16, the cooling water discharge pipe 62 is arranged on the front side, and the cooling water supply pipe 61 is arranged on the rear side. 61 and the cooling water discharge pipe 62 can be more freely laid out, and the combustion chamber insert 16 for each cylinder can be uniformly cooled.

(7) As shown in FIG. 1, the cooling water supply pipe 61 and the cooling water discharge pipe 62 for the second cylinder from the left are arranged on the straight line M parallel to the front-rear direction, and the remaining cooling is performed. By disposing the water supply pipe 61 and the cooling water discharge pipe 62 substantially along the straight line M, the layout of the cooling water supply pipe 61 and the cooling water discharge pipe 62 can be simplified, and the manufacture becomes easy. The flow resistance of the cooling water is reduced, and a rapid flow of the cooling liquid can be maintained.

(8) Since the annular air layer S1 is formed by forming the small diameter portion 16c on the outer peripheral surface of the combustion chamber insert 16 as shown in FIG. 8, the combustion chamber insert 16 and the lower mold insert 14 The space is insulated by the annular air layer S1, and cooling in the combustion chamber insert 16 can be promoted. Further, the cooling water leaked from the connection portion between the combustion chamber insert 16 and the cooling water supply pipe 61 and the cooling water discharge pipe 62 is quickly discharged outside the mold through the annular air layer S1 and the water leakage receiving plate 67. be able to.

(9) Since the molten metal is poured from the spout 17 of the lower mold 1, the solidification of the molten metal moves downward from the upper end portion. Since the spark plug insertion hole forming insert 22 and the combustion chamber insert 16 of the lower mold 1 are cooled, the ignition plug insertion hole forming insert 22 and the combustion chamber insert 16 can be appropriately cooled according to the solidified state.

[Other embodiments]
(1) In the above-described embodiment, the combustion chamber forming portion is provided separately from the lower mold insert 14 and provided with the independent combustion chamber insert 16. However, the combustion chamber forming is integrated with the lower mold insert 14. It is also possible to have a structure in which a portion is formed.

(2) The present invention can also be applied to a mold having no slide mold, that is, a mold composed of a lower mold and an upper mold. Further, the present invention can be applied to a mold having only one of a front and rear slide mold or a left and right slide mold as a slide mold.

(3) In the time chart of FIG. 12, the end of cooling of the spark plug insertion hole forming insert 22 (t2) and the start of cooling of the combustion chamber insert 16 (t3) are matched. It is also possible to start the cooling of the combustion chamber insert 16 before the cooling of the hole forming insert 22 is completed. It is also possible to start the cooling of the combustion chamber insert 16 after a while after the cooling of the spark plug insertion hole forming insert 22 is completed.

(4) The shape of the cooling water passage 53 of the combustion chamber insert 16 is not limited to the inverted V shape as shown in FIG. 8, and various shapes such as a downward U shape can be adopted. .

(5) The mold according to the present invention is not limited to the casting of a cylinder head of a four-cylinder engine, and can be applied to a casting mold of a cylinder head of a single cylinder or other multiple cylinder engines.

1 Lower mold 2 Upper mold 3 and 4 Slide type (horizontal type)
5, 6 Left and right slide type (horizontal type)
11 Lower mold main mold 13 Lower mold insert spacer 14 Lower mold insert 16 Combustion chamber insert (an example of a combustion chamber forming part)
16 Upper surface of combustion chamber insert (top wall molding part)
17 Gate 18 Gate
22 spark plug insertion hole insert (an example of a spark plug insertion hole forming part)
32 Front and rear slide type rails 33 Intake hole forming section 34 Exhaust hole forming section 51 Cooling water passage inlet 52 Cooling water passage outlet 53 Combustion chamber cooling water passages 53a, 53b, 53c, 53d First and second , Third and fourth passage portions 61 Combustion chamber cooling water supply pipe 62 Combustion chamber cooling water discharge pipe
S1 annular air layer S2 space

Claims (9)

A lower mold for forming the lower surface of the cylinder head and an upper mold for forming the upper surface of the cylinder head are provided at least, and the lower mold is provided with a combustion chamber forming portion for forming the top wall of the combustion chamber of the cylinder head. In the cooling device for the cylinder head casting mold,
A coolant passage is formed in the combustion chamber forming part,
A coolant supply passage and a coolant discharge passage are connected to the inlet and the outlet of the coolant passage, respectively.
The coolant supply passage and the coolant discharge passage are arranged in the lower mold portion on one side and the lower mold portion on the other side so that cooling water flows from one side to the other side with respect to the combustion chamber forming portion. It is arranged separately in and
A pair of opposed slide molds for molding the outer peripheral side wall surface of the cylinder head,
The cooling device for a cylinder head casting mold , wherein the cooling liquid supply passage and the cooling liquid discharge passage are arranged separately on one slide mold arrangement side and the other slide side arrangement side . 2. The cooling device for a cylinder head casting mold according to claim 1 , wherein the coolant supply passage and the coolant discharge passage are disposed at positions that do not interfere with the slide rails of the slide types. The cooling liquid supply passage and the cooling liquid discharge passage are constituted by a cooling liquid supply pipe and a cooling liquid discharge pipe, respectively.
The cylinder head casting according to claim 1 or 2 , wherein the cooling liquid supply pipe and the cooling liquid discharge pipe are arranged in a tunnel-shaped passage formed in the lower mold with an annular space portion therebetween. Mold cooling device. A plurality of the combustion chamber forming portions are arranged in a substantially straight line;
4. The cylinder head casting according to claim 1 , wherein the pair of slide dies are arranged on the one side and the other side with respect to the straight line of the combustion chamber forming portions. 5. Mold cooling device. The cylinder head casting die cooling apparatus according to any one of claims 1 to 4, wherein the coolant supply passage and the coolant discharge passage are arranged in a substantially straight line. The combustion chamber forming part is formed by combustion chamber nesting,
The cooling device for a cylinder head casting mold according to any one of claims 1 to 5 , wherein the coolant passage in the combustion chamber insert is formed in a substantially V shape. The combustion chamber forming part is formed by combustion chamber nesting,
A small-diameter portion is formed on the outer peripheral surface of the combustion chamber insert via a stepped portion
The cylinder head casting die cooling device according to any one of claims 1 to 6 , wherein an annular air layer is formed on an outer periphery of all the small diameter portions. The coolant supply passage and the coolant discharge passage are connected to an inlet and an outlet of the combustion chamber insert, respectively.
8. The cooling device for a cylinder head casting mold according to claim 7 , wherein a leakage discharge passage is formed below the combustion chamber insert. 9. A method for controlling a cooling device for a cylinder head casting mold, wherein a cooling liquid passage for an ignition plug insertion hole forming portion is formed in the upper spark plug insertion hole forming portion according to claim 1. In
Control of the cooling device for the cylinder head casting mold, after supplying the coolant to the coolant passage for the spark plug insertion hole molding section and then supplying the coolant to the coolant path of the combustion chamber molding section. Method.

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