The present invention relates to a casting device equipped with a lower mold fixed to a base, an upper mold arranged to face toward the lower mold and which is capable of moving up and down with respect to the lower mold, and a slide member arranged slidably with respect to the base.
In relation to this type of casting device, a configuration is disclosed in Japanese Laid-Open Patent Publication No. 2013-086118 in which four support posts (positioning members) are provided on a base, and by which an upper mold and slide molds (slide members) are brought into contact with each other to thereby specify positions of the upper mold and the slide molds at a time of mold clamping.
Incidentally, for example, in the case that a cylinder head of an automobile engine is cast with the casting device, the installation location of the support posts is limited by such features as the shape of the cylinder head (cast product) and the like, and situations may occur in which it is impossible to sufficiently secure the rigidity of the support posts. If this occurs, when the slide molds are placed in abutment against the support posts, the support posts may become inclined with respect to the base, and the slide molds may also become inclined with respect to the base.
If the slide molds become inclined with respect to the base, galling tends to occur and the cast product cannot be cast with high precision. In particular, in the case that casting is carried out using sand cores, the positions of the sand cores may become shifted or damage to the sand cores may occur. Further, in the case that the slide molds themselves collide with each other, the useful lifetime of the slide molds may be shortened, or it may be necessary to repair the molds at the parting line in certain cases.
It may also be considered to suppress inclination of the support posts when the slide molds come into contact with the support posts by adjusting the clamping force of the slide molds (the speed of movement of the slide molds at the time of mold clamping). However, in this case, it is necessary to adjust the clamping force of the slide molds every time that the shape of the cast product changes, which leads to a concern that the cycle time will become prolonged.
The present invention has been devised taking into consideration the aforementioned problems, and has the object of providing a casting device which is capable of casting cast products with high precision together with shortening the cycle time.
In order to achieve the aforementioned object, a casting device according to the present invention comprises a base, a lower mold fixed to the base, a slide member disposed so as to be capable of sliding with respect to the base, an upper mold arranged in facing relation and vertically movable with respect to the lower mold, a positioning member disposed on the base and configured to come into contact with the upper mold and the slide member to thereby specify positions of the upper mold and the slide member at a time of mold clamping, and a restraining force applying mechanism configured to apply a restraining force to the slide member in a direction opposite to a pressing force exerted on the positioning member from the slide member at the time of mold clamping of the slide member.
In accordance with the casting device which is configured in the above-described manner, since the pressing force exerted on the positioning member from the slide member can be suitably reduced by the restraining force of the restraining force applying mechanism, it is possible to prevent the positioning member from being inclined with respect to the base. Consequently, it is possible to suppress inclination of the slide member with respect to the base without adjusting the mold clamping force of the slide member, and therefore, it is possible for cast products to be cast with high precision together with shortening the cycle time.
In the above-described casting device, the slide member may include a first slide mold and a second slide mold arranged so as to face toward each other mutually, and the positioning member may include a first support post provided on the base and abutting against the upper mold and the first slide mold to thereby specify the positions of the upper mold and the first slide mold at the time of mold clamping, and a second support post provided on the base and abutting against the upper mold and the second slide mold to thereby specify the positions of the upper mold and the second slide mold at the time of mold clamping, and the casting device may further comprise a tie rod connected to the first slide mold and extended along a direction in which the first slide mold slides. The restraining force applying mechanism may be disposed on the tie rod and may apply a restraining force to the first slide mold which is opposite to a pressing force exerted on the first support post from the first slide mold at the time of mold clamping of the first slide mold.
In accordance with such a configuration, it is possible to suppress inclination of the first support post and the first slide mold with respect to the base.
In the above-described casting device, the restraining force applying mechanism may include a spring member configured to apply a spring force as the restraining force to the first slide mold before the first slide mold comes into contact with the first support post.
In accordance with such a configuration, the restraining force can be applied efficiently to the first slide mold by the spring force of the spring member. Consequently, with a simple configuration, it is possible to reliably suppress inclination of the first support post and the first slide mold.
In the above-described casting device, the tie rod may be disposed so as to penetrate through the second support post, and the spring member may be supported on the tie rod in a state of being positioned between the first slide mold and the second support post.
In accordance with such a configuration, the spring member, which is located between the first slide mold and the second support post at the time of mold clamping of the first slide mold, is pressed by the first slide mold and is elastically deformed. Therefore, the spring force of the spring member can be applied as a restraining force to the first slide mold. Further, since the spring force of the spring member can be applied to the second support post at the time of mold clamping of the first slide mold, it is possible to suppress inclination of the second support post with respect to the base due to the pressing force exerted on the second support post from the second slide mold at the time of mold clamping of the second slide mold.
In the above-described casting device, the restraining force applying mechanism may include a tubular spacer disposed on an outer circumferential side of the tie rod, and configured to press the spring member at the time of mold clamping of the first slide mold.
In accordance with such a configuration, even in the case that the total length of the spring member is comparatively short, the spring member can be elastically deformed reliably via the spacer at the time of mold clamping of the first slide mold.
In the above-described casting device, the restraining force applying mechanism may include a flange member disposed on the tie rod and positioned between the spring member and the first slide mold, and configured to press the spring member at the time of mold clamping of the first slide mold.
In accordance with such a configuration, even in the case that the total length of the spring member is comparatively short, the spring member can be elastically deformed reliably via the flange member at the time of mold clamping of the first slide mold.
In the above-described casting device, the restraining force applying mechanism may further comprise a movable shaft positioned on an opposite side of the first slide mold from that of the second slide mold, and provided on the tie rod in a state of being extended along an axial direction of the tie rod, a flange member provided on the movable shaft, and a fixed member disposed between the first slide mold and the flange member in a state of being immovable in the axial direction of the tie rod. The spring member may be interposed between the fixed member and the flange member in a state of being supported on the movable shaft.
In accordance with such a configuration, the spring member, which is located between the flange member and the fixed member at the time of mold clamping of the first slide mold, is pressed by the flange member and is elastically deformed. Therefore, the spring force of the spring member can be applied as a restraining force to the first slide mold. Consequently, it is possible to suppress inclination of the first support post and the first slide mold with respect to the base.
In the above-described casting device, the restraining force applying mechanism may further comprise a pressing member positioned on an opposite side of the second slide mold from that of the first slide mold, and provided on the tie rod, a support member disposed on an opposite side of the pressing member from that of the first slide mold in a state of being immovable in the axial direction of the tie rod, and a fixed shaft disposed on the support member, and extended along the axial direction of the tie rod so as to penetrate through the pressing member. The spring member may be interposed between the pressing member and the support member in a state of being supported on the fixed shaft.
In accordance with such a configuration, the spring member, which is located between the pressing member and the support member at the time of mold clamping of the first slide mold, is pressed by the pressing member and is elastically deformed. Therefore, the spring force of the spring member can be applied as a restraining force to the first slide mold. Consequently, it is possible to suppress inclination of the first support post and the first slide mold with respect to the base.
According to the present invention, since the pressing force exerted on the positioning member from the slide member can be suitably reduced by the restraining force of the restraining force applying mechanism, it is possible for cast products to be cast with high precision together with shortening the cycle time.
Preferred embodiments of a casting device according to the present invention will be presented and described in detail below with reference to the accompanying drawings.
A casting device 10 according to the present embodiment is a device used for casting, for example, a cylinder head of an in-line four-cylinder engine for an automobile by a low pressure casting method. However, the casting device 10 may be used as a device for casting a cast product having a shape other than the aforementioned cylinder head.
As shown in
The lower mold 14, which has a rectangular shape viewed in plan and is used for molding a lower surface of the cylinder head, is disposed on the base 12. Four combustion chamber molding sections 24 that serve to mold the combustion chambers of the cylinder head are provided on the lower mold 14 along the longitudinal direction of the lower mold 14. An intake side sand core 26 for molding an intake port, and an exhaust side sand core 28 for molding an exhaust port are connected to each of the combustion chamber molding sections 24. The intake side sand cores 26 and the exhaust side sand cores 28 face toward each other along a lateral direction of the lower mold 14. A plurality of first to fourth guide rails 30a to 30d are disposed on the base 12. The first guide rails 30a are positioned on a side (in the X1 direction) where the intake side sand cores 26 are located with respect to the combustion chamber molding sections 24, and the second guide rails 30b are positioned on a side (in the X2 direction) where the exhaust side sand cores 28 are located with respect to the combustion chamber molding sections 24. The first guide rails 30a and the second guide rails 30b extend along the lateral direction of the lower mold 14. Further, the third guide rails 30c are positioned on one side (in the Y1 direction) in the longitudinal direction of the lower mold 14 with respect to the combustion chamber molding sections 24, and the fourth guide rails 30d are positioned on another side (in the Y2 direction) in the longitudinal direction of the lower mold 14 with respect to the combustion chamber molding sections 24. The third guide rails 30c and the fourth guide rails 30d extend along the longitudinal direction of the lower mold 14. The slide member 16 has first to fourth slide molds 32a to 32d. The first slide mold 32a includes a first slide mold main body 34a adapted to mold a side surface in the X1 direction of the cylinder head, and a first sliding plate 36a to which the first slide mold main body 34a is fixed, and which slides along the first guide rails 30a. The second slide mold 32b includes a second slide mold main body 34b adapted to mold a side surface in the X2 direction of the cylinder head, and a second sliding plate 36b to which the second slide mold main body 34b is fixed, and which slides along the second guide rails 30b.
The third slide mold 32c includes a third slide mold main body 34c adapted to mold a side surface in the Y1 direction of the cylinder head, and a third sliding plate 36c to which the third slide mold main body 34c is fixed, and which slides along the third guide rails 30c. The fourth slide mold 32d includes a fourth slide mold main body 34d adapted to mold a side surface in the Y2 direction of the cylinder head, and a fourth sliding plate 36d to which the fourth slide mold main body 34d is fixed, and which slides along the fourth guide rails 30d.
The upper mold 18 includes an upper mold main body 38 adapted to mold an upper surface of the cylinder head, and a movable plate 40 to which the upper mold main body 38 is fixed, and which is moved up and down by a non-illustrated drive mechanism.
The positioning member 20 includes a pair of first support posts 42, 44 disposed on the X1 side of the base 12 in alignment with the longitudinal direction of the lower mold 14, and a pair of second support posts 46, 48 disposed on the X2 side of the base 12 in alignment with the longitudinal direction of the lower mold 14. The transverse cross section of the first support post 42 is formed in a rectangular shape, and the transverse cross section of the second support post 46 is formed in an L-shape.
A transverse cross-sectional area of the first support post 42 is smaller than the transverse cross-sectional area of the second support post 46. More specifically, the first support post 42 has a lower rigidity than that of the second support post 46. A height of the first support post 42 and a height of the second support post 46 are set to be equal to each other. The first support post 44 is configured in the same manner as the first support post 42, and the second support post 48 is configured in the same manner as the second support post 46, and therefore, detailed descriptions of the first support post 44 and the second support post 46 are omitted.
The pair of first support posts 42, 44 contact the movable plate 40 and the first sliding plate 36a, and regulate the positions of the upper mold 18 and the first slide mold 32a at the time of mold clamping. The pair of second support posts 46, 48 contact the movable plate 40 and the second sliding plate 36b, and regulate the positions of the upper mold 18 and the second slide mold 32b at the time of mold clamping. Further, the one first support post 42 and the one second support posts 46 contact the third sliding plate 36c, and regulate the position of the third slide mold 32c at the time of mold clamping. The other first support post 44 and the other second support post 48 contact the fourth sliding plate 36d, and regulate the position of the fourth slide mold 32d at the time of mold clamping.
As shown in
The casting device 10 is further equipped with a restraining force applying mechanism 58 adapted to apply a restraining force to the first slide mold 32a, the restraining force being in an opposite direction to a pressing force exerted on the pair of first support posts 42, 44 from the first slide mold 32a at the time of mold clamping of the first slide mold 32a.
The restraining force applying mechanism 58 includes a first spring member 60 and a first spacer 62, which are provided on the upwardly positioned tie rod 50 in the Y1 direction, and a second spring member 64 and a second spacer 66, which are provided on the upwardly positioned tie rod 52 in the Y2 direction.
The first spring member 60 is supported on the tie rod 50 in a state of being positioned between the first sliding plate 36a and the second support post 46. For example, a compression coil spring is suitably used as the first spring member 60. However, any arbitrary type of spring such as a disc spring or the like can be used.
The first spacer 62 is a tubular member provided on an outer circumferential side of the tie rod 50, and is positioned between the first sliding plate 36a and the first spring member 60. More specifically, the first spring member 60 is interposed between the second support post 46 and the end surface of the first spacer 62. The first spacer 62 is constituted, for example, from a metal including iron or the like. The spring constant of the first spring member 60 as well as the length of the first spacer 62 are set appropriately depending on the magnitude of the spring force (restraining force) of the first spring member 60 to be exerted on the first sliding plate 36a.
The second spring member 64 and the second spacer 66 are configured in the same manner as the above-described first spring member 60 and the first spacer 62, and therefore, detailed description thereof is omitted.
In the restraining force applying mechanism 58, the positions of the first spring member 60 and the first spacer 62 may be reversed, and the first spring member 60 may be interposed between the first sliding plate 36a and an end surface of the first spacer 62. The same applies to the second spring member 64 and the second spacer 66.
Further, the first spacer 62 and the second spacer 66 may be dispensed with, and the first spring member 60 may be disposed over the entire length from the first sliding plate 36a up to the second support post 46, together with the second spring member 64 being disposed over the entire length from the first sliding plate 36a up to the second support post 48. Even with such a configuration, a predetermined restraining force can be applied with respect to the first sliding plate 36a by the first spring member 60 and the second spring member 64 at the time of mold clamping of the first slide mold 32a.
The casting device 10 according to the present embodiment is basically configured in the manner described above. Next, operations and effects of the casting device 10 will be described. In the following description, a mold opened state of the slide member 16 and the upper mold 18 is defined as an initial state. Moreover, as shown in FIG. 3A, in the opened state of the slide member 16, the first sliding plate 36a is not in contact with the first support posts 42, 44, and the second sliding plate 36b is also not in contact with the second support posts 46, 48.
In the case that casting of the cylinder head is to be carried out by the casting device 10, the intake side sand cores 26 and the exhaust side sand cores 28 are arranged respectively in each of the combustion chamber molding sections 24 provided on the lower mold 14, and a mold clamping process of the first to fourth slide molds 32a to 32d is performed.
More specifically, the tie rods 50, 52, 54, 56 are moved in the X2 direction by a non-illustrated drive mechanism, whereby the first slide mold 32a is made to slide in the X2 direction along the first guide rails 30a, and the second slide mold 32b is made to slide in the X1 direction along the second guide rails 30b. Further, by the non-illustrated drive mechanism, the third slide mold 32c is made to slide in the Y2 direction along the third guide rails 30c, and the fourth slide mold 32d is made to slide in the Y1 direction along the fourth guide rails 30d.
As shown in
In addition, the first slide mold 32a is stopped by the first sliding plate 36a coming into abutment against the first support posts 42, 44, and the second slide mold 32b is stopped by the second sliding plate 36b coming into abutment against the second support posts 46, 48. In the same manner, the third slide mold 32c is stopped by the third sliding plate 36c coming into abutment against the first support post 42 and the second support post 46, and the fourth slide mold 32d is stopped by the fourth sliding plate 36d coming into abutment against the first support post 44 and the second support post 48.
At this time, since the spring force in the X1 direction is applied as a restraining force to the first sliding plate 36a, the pressing force in the X2 direction, which is exerted on the first support posts 42, 44 from the first sliding plate 36a, is suitably reduced. Consequently, even in the case that it is necessary for the rigidity of the first support posts 42, 44 to be kept comparatively low due to the layout relationship, in accordance with the pressing force received by the first support posts 42, 44 from the first sliding plate 36a, any inclination in the X2 direction with respect to the base 12 can be suppressed. Further, the spring force in the X2 direction is exerted on the second support post 46 from the first spring member 60, and together therewith, the spring force in the X2 direction is exerted on the second support post 48 from the second spring member 64. Therefore, when the pressing force in the X1 direction is exerted from the second sliding plate 36b on the second support posts 46, 48, the second support posts 46, 48 are prevented from becoming inclined in the X1 direction with respect to the base 12. In this manner, since the first slide mold main body 34a and the second slide mold main body 34b are prevented from becoming inclined with respect to the lower mold 14, the intake side sand cores 26 and the exhaust side sand cores 28 are not shifted in position or damaged. Further, collision of the first slide mold 32a (or the second slide mold 32b ) against the third slide mold 32c and the fourth slide mold 32d is also avoided.
Subsequently, the upper mold 18 is displaced downward by the non-illustrated drive mechanism. The upper mold 18 is stopped by the movable plate 40 coming into abutment against upper surfaces of the first support posts 42, 44 and upper surfaces of the second support posts 46, 48. Accordingly, the cavity 22 having a shape corresponding to the shape of the cylinder head is formed by the lower mold 14, the first to fourth slide mold main bodies 34a to 34d, and the upper mold main body 38.
Thereafter, a molten metal, which is stored in a non-illustrated crucible provided under the base 12, is supplied to the cavity 22 through a gate. Consequently, the molten metal is filled in the cavity 22, and the cylinder head is cast. Following mold opening of the upper mold 18 and the first to fourth slide molds 32a to 32d, the cast cylinder head is taken out. At this time, since inclination of the first slide mold 32a and the second slide mold 32b with respect to the base 12 is suppressed, the occurrence of galling can be prevented.
According to the present invention, the restraining force, which is in an opposite direction to the pressing force exerted on the first support posts 42, 44 from the first sliding plate 36a at the time of mold clamping of the first slide mold 32a, is applied to the first sliding plate 36a from the first spring member 60 and the second spring member 64. Therefore, it is possible to suitably reduce the pressing force that acts on the first support posts 42, 44. Owing to this feature, it is possible to suppress inclination of the first support posts 42, 44 with respect to the base 12. Thus, without adjusting the mold clamping force (speed of movement) of the first slide mold 32a, it is possible to suppress inclination of the first slide mold 32a with respect to the base 12. Accordingly, it is possible for cast products to be cast with high precision together with shortening the cycle time.
Further, according to the present embodiment, the first spring member 60 and the second spring member 64 are elastically deformed before the first sliding plate 36a comes into contact with the first support posts 42, 44, and therefore, it is possible for a predetermined restraining force to be applied efficiently to the first sliding plate 36a. Consequently, with a simple configuration, it is possible to reliably suppress inclination of the first slide mold 32a.
Furthermore, the first spacer 62 is disposed between the first sliding plate 36a and the first spring member 60, and together therewith, the second spacer 66 is disposed between the first sliding plate 36a and the second spring member 64. In accordance therewith, even in the case that the total lengths of the first spring member 60 and the second spring member 64 are comparatively short, the first spring member 60 and the second spring member 64 can be elastically deformed reliably at the time of mold clamping of the first slide mold 32a.
Further still, at the time of mold clamping of the first slide mold 32a, a spring force in the X2 direction is exerted on the second support post 46 from the first spring member 60, and together therewith, a spring force in the X2 direction is exerted on the second support post 48 from the second spring member 64. Therefore, at the time of mold clamping of the second slide mold 32b, it is possible to suppress inclination of the second support posts 46, 48 with respect to the base 12 due to the pressing force exerted on the second support posts 46, 48 in the X1 direction from the second sliding plate 36b.
The casting device 10 according to the present embodiment is not limited to the configuration described above. Instead of the restraining force applying mechanism 58, the casting device 10 may be equipped with restraining force applying mechanisms 58a to 58c according to the following first to third modifications described below.
As shown in
According to the present modification, the first flange member 70 is disposed integrally with respect to the tie rod 50. However, the first flange member 70 may be constructed separately from the tie rod 50, and may be fixed to the tie rod 50 using a fastening member or the like. The second flange member 72 is configured in the same manner as the first flange member 70, and therefore, detailed description thereof is omitted.
In accordance with such a configuration, the same effects are exhibited as those of the case in which the above-described restraining force applying mechanism 58 is provided. More specifically, as shown in
As shown in
Further, the first mechanism 74 includes a fixed member 82 disposed on the base 12 in a manner so that the movable shaft 78 penetrates through the fixed member 82 in a state that the fixed member 82 is immovable in the axial direction of the tie rod 50, and a spring member 84 interposed between the flange member 80 and the fixed member 82 in a state of being supported by the movable shaft 78. The fixed member 82 may be fixed to a floor surface without necessarily being disposed on the base 12. The spring member 84 is configured in the same manner as the aforementioned first spring member 60. The second mechanism 76 is configured in the same manner as the first mechanism 74, and therefore, detailed description thereof is omitted.
In accordance with such a configuration, as shown in
As shown in
Further, the restraining force applying mechanism 58c includes a fixed shaft 90 which is fixed to the support member 88 and extends in an axial direction of the tie rod 50 so as to penetrate through the pressing member 86, and a stopper member 92 disposed on an end in the X1 direction of the fixed shaft 90. A spring member 94 is interposed between the pressing member 86 and the support member 88 in a state of being supported on the fixed shaft 90. The support member 88 may be fixed to the base 12 and not to the floor surface. The spring member 94 is configured in the same manner as the aforementioned first spring member 60.
In accordance with such a configuration, as shown in
In the casting device 10 according to the present embodiment, a restraining force applying mechanism may further be provided in which, for example, a restraining force is applied to the third slide mold 32c in a direction opposite to the pressing force exerted on the first support post 42 and the second support post 46 from the third slide mold 32c. The restraining force applying mechanism may adopt the same configuration as any of the restraining force applying mechanisms 58 and 58a to 58c described above. Moreover, in this case, a plurality of tie rods that extend along the longitudinal direction of the lower mold 14 are further provided. In accordance with such a configuration, the pressing force exerted on the first support post 42 and the second support post 46 from the third slide mold 32c can be suitably reduced, and therefore, it is possible to prevent inclination of the first support post 42 and the second support post 46 with respect to the base 12.
The restraining force applying mechanism may be configured in a manner so that a restraining force is applied to the fourth slide mold 32d in a direction opposite to the pressing force exerted on the first support post 44 and the second support post 48 from the fourth slide mold 32d. In this case, the pressing force exerted on the first support post 44 and the second support post 48 from the fourth slide mold 32d can be suitably reduced, and therefore, it is possible to prevent inclination of the first support post 44 and the second support post 48 with respect to the base 12.
Number | Date | Country | Kind |
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2015-132544 | Jul 2015 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2016/068992 | 6/27/2016 | WO | 00 |