The present application relates to and asserts priority from Japanese patent application No. 2023-054500 filed on Mar. 30, 2023, and incorporates the entirety of the contents and subject matter of all the above application herein by reference.
The present invention relates to a casting die and a casting method.
Heretofore, there has been known a casting die including a movable core insertable into and withdrawable from a cavity formed between a stationary die and a movable die (for example, see JPH03-009885Y). This casting die includes a first movable core and a second movable core. The first movable core and the second movable core are engaged with each other when a molten metal is poured into the casting die.
In this casting die, the movable cores are prevented from displacing when the molten metal is poured under high pressure, so that the dimensional accuracy of a cast product obtained in the die can be improved.
In the case of the casting die in the related art (for example, JP1991-009885Y), the first movable core and the second movable core need to be engaged with each other and positioned with high accuracy in order to prevent these cores from moving in an application direction of a casting pressure. Therefore, the casting die in the related art has a problem that the freedom in design is restricted.
Moreover, the casting die in the related art has a problem that the maintenance in the case where the first movable core and the second movable core malfunction due to thermal expansion is difficult.
An object of the present invention is to provide a casting die and a casting method that enable higher freedom in design and easier maintenance than in the related art.
A casting die of the present invention achieving the above object includes: a stationary die; a movable die that is moved to come into and out of contact with the stationary die; and a sliding die provided to the movable die so as to be insertable and withdrawable in a direction crossing a movement direction of the movable die and configured to form a cavity in collaboration with the stationary die and the movable die, wherein the sliding die includes: a slider core that is moved by a first moving mechanism so as to be insertable and withdrawable along the movement direction of the movable die; and a stopper that is moved by a second moving mechanism between a locking position at which the stopper is in contact with the slider core at a die closing position and locks the slider core, and an unlocking position at which the stopper is separated from the slider core and unlocks the slider core.
Further, a casting method of the present invention achieving the above object is a casting method using a casting die including: a stationary die; a movable die that is moved to come into and out of contact with the stationary die; and a sliding die provided to the movable die so as to be insertable and withdrawable in a direction crossing a movement direction of the movable die and configured to form a cavity in collaboration with the stationary die and the movable die, the sliding die including: a slider core that is moved so as to be insertable and withdrawable along the movement direction of the movable die; and a stopper that comes into contact with the slider core at a die closing position and locks the slider core, the method comprising: a moving step of moving the stopper to the slider core; a locking step of positioning and locking the slider core by adjusting a position of the stopper so that a tip of the slider core forms the cavity; a die release agent applying step of applying a die release agent to at least a surface of the stationary die, a surface of the movable die, and a surface of the sliding die, which form the cavity; and a die closing step of placing the sliding die at a sliding die clamping position, and closing the movable die onto the stationary die.
According to the present invention, it is possible to provide a casting die and a casting method that enable higher freedom in design and easier maintenance than in the related art.
Hereinafter, modes (embodiments) for carrying out a casting die and a casting method of the present invention will be described in detail with reference to the drawings when necessary.
As shown in
The following description will be given by taking, as an example, the casting die 1 for casting a vehicle body structure by using a molten metal of recycled aluminum, but the cast product and the molten metal are not limited to these.
In the present embodiment, the shape of the cast product 7 obtained with the casting die 1 will be specifically described first, and then the casting die 1 and the casting method using the same will be described.
As shown in
This vehicle body structure 10 in
The side frame 11 is a long member extending in a vehicle front-rear direction on each of the right and left sides of a vehicle body front portion and a vehicle body rear portion.
The side frames 11 are coupled to a bumper beam extension (not shown), and the rear ends of the right and left side frames 11 are coupled to each other via a panel-shaped dashboard lower 16 (see
The upper member 12 is formed of a long member extending rearward outside the side frame 11 in a vehicle width direction while forming an upwardly-convex substantially circular arc.
The wheel house 13 is united with a wheel house outer half (not shown) to form a space for housing a tire wheel. In other words, the wheel house 13 of the vehicle body structure 10 shown in
As shown in
A vehicle-widthwise outer side of the upper wall 13a is connected to the upper member 12. Then, a vehicle-widthwise outer side of the wheel house 13 has an opening shaped like a circular arc (not shown), and a back surface (lower surface) of the upper wall 13a of the wheel house 13 is formed along a sliding direction of the sliding die 4 (in the right-left direction in
The damper housing 14 is formed such that the wheel house 13 partially protrudes upward. The damper housing 14 has an internal space common to the wheel house 13. Then, a vehicle-widthwise outer side of the damper housing 14 is opened together with the opening of the wheel house 13 so that the sliding die 4 to be described later (see
An upper edge of the vehicle-widthwise outer side of the damper housing 14 is connected to the upper member 12. A portion of the upper member 12 to be connected to the damper housing 14 has an L-shaped cross-sectional shape, although that is not shown. Then, a portion of the upper member 12 to be connected to the wheel house 13 has a U-shaped cross-sectional shape opened to the vehicle-widthwise outer side.
A damper base 15 to which a damper (not shown) is to be attached is formed on a top portion of the damper housing 14. Specifically, the damper base 15 is formed in a dome shape further expanding upward from the top portion of the damper housing 14.
The inside of the damper base 15 forms an internal space in a columnar shape so that a slider core 5 (see
The casting die 1 (see
The casting die 1 (see
Note that the front-rear, top-bottom, and right-left directions shown in
As shown in
As shown in
As shown in
In addition, as shown in
The sliding dies 4 can be opened in the right-left direction from the movable die 3 separated from the stationary die 2. The sliding dies 4 are slid relative to the movable die 3 by driving rods 4a as shown in
Then, each sliding die 4 includes a slider core 5 and a stopper 6 for the slider core 5 as shown in
As shown in
The slider core 5 also has a rod 5b extending from a bottom surface of the core body 5a downward.
The slider core 5 also has a hydraulic cylinder 5c connected to a bottom edge of the rod 5b as shown in
The hydraulic cylinder 5c shown in
Then, as shown in
Moreover, as shown in
As shown in
The stopper 6 locks the slider core 5 by coming into contact with a bottom surface 5a1 of the core body 5a as shown in
Specifically, the stopper 6 is placed at a locking position at which the tip of the core body 5a is positioned at the casting position P1.
Moreover, the stopper 6 can come into and out of contact with the slider core 5 by being moved by the hydraulic cylinder 6c in the right-left direction as shown in
In addition, as shown in
Thus, as shown in
In other words, with adjustment of the position of the stopper 6 in the movement direction D1, the stopper 6 is capable of positioning and locking the tip of the core body 5a at the casting position P1.
Although the contact surface of the stopper 6 with the bottom surface 5a1 of the core body 5a (the top surface 6a of the stopper 6) is inclined in the present embodiment, the bottom surface 5a1 of the core body 5a may be also inclined with respect to the movement direction D1 of the stopper 6.
That is, any structure may be used as long as the slider core 5 is moved in the movement direction D2 as the stopper 6 is moved in the movement direction D1.
Therefore, only at least one of the top surface 6a of the stopper 6 and the bottom surface 5a1 of the core body 5a has to be inclined with respect to the movement direction D1 of the stopper 6.
In addition, as shown in
Then, the stopper 6 at the locking position is located to put the rod 5b of the slider core 5 in contact with the inner sides of the bifurcate tips as shown in
Next, the casting method using the casting die 1 will be described mainly in reference to
The casting method in the present embodiment includes: [1] a moving step of moving the stopper 6 to the core body 5a of the slider core 5; [2] a locking step of positioning and locking the core body 5a by adjusting the position of the stopper 6 so that the tip of the core body 5a forms the cavity C5; [3] an applying step of spraying and applying a die release agent to the surface of the stationary die 2, the surface of the movable die 3, the surfaces of the sliding dies 4, and the surfaces of the core bodies 5a, which will form the cavity C (see
In addition, the casting method in the present embodiment includes: [8] a die opening step of separating the movable die 3 united with the sliding dies 4 from the stationary die 2; [9] a preliminary pushing step of pushing the core body 5a at the casting position P1 (see
The casting method in the present embodiment produces cast products 7 (see
As shown in
In this step, as shown in step S101, the core body 5a is first pushed up by the hydraulic cylinder 5c (see
Then, as shown in step S102, in the state where the core body 5a is pushed up to the protrusion limit position P2, the stopper 6 is moved toward the core body 5a by the hydraulic cylinder 6c (see
Next, as shown in step S103, the core body 5a is lowered in the state where the stopper 6 is located under the core body 5a. In this step, the position of the stopper 6 relative to the core body 5a is set to the above locking position. Here, the core body 5a is assumed to be lowered by the hydraulic cylinder 5c (see
Then, as shown in step S104, [2] the locking step is completed in the state where the core body 5a at the casting position P1 is in contact with the stopper 6.
Subsequently, in this casting method, as shown in step S105, [3] the die release agent applying step, [4] the die closing step of the sliding dies 4, and [5] the die closing step of the movable die 3 are performed. As a result, the cavity C (see
In [9] the preliminary pushing step, the core body 5a is pushed up from the casting position P1 to the protrusion limit position P2 by the hydraulic cylinder 5c (see
As a result, in [9] the preliminary pushing step, the damper base 15 (cast product) on the core body 5a is separated from the core body 5a with slight elastic deformation. A clearance is formed between the core body 5a and the damper base 15.
In the unlocking step, as shown in step S109, the stopper 6 is moved away from the core body 5a and set at the unlocking position by the hydraulic cylinder 6c (see
Subsequently, in the core pull-in step, as shown in step S110, the core body 5a is pulled into the sliding die 4 by the hydraulic cylinder 5c (see
After that, as shown in S111, the sliding die opening step and the step of taking out the cast product 7 (see
Next, effects produced by the casting die 1 and the casting method according to the present embodiment will be described.
The casting die 1 in the present embodiment includes the sliding dies 4 constituting the portions of the cavity C, and each sliding die 4 includes the slider core 5 and the hydraulic cylinder 5c as the mechanism of moving the slider core 5.
In the casting die 1 as described above, the maintenance of the slider core 5 can be easily carried out by taking out only the sliding die 4 from the main die, namely, the movable die 3, unlike a casting die in the related art (for example, see JP1991-9885Y). The casting die 1 enables reductions in person-hours and the work time for the maintenance.
According to the casting die 1 as described above, the simple structure is capable of positioning the dies for forming the cavity with higher accuracy than in the case of a casting die in the related art which requires a first movable core and a second movable core to be engaged with each other and positioned with high accuracy. As a result, the casting die 1 can prevent the molten metal from being inserted between the dies even when the molten metal is injected under high pressure. In addition, the casting die 1 can reduce the influence of thermal expansion of the slider core 5. With the casting die 1, it is possible to improve the shaping accuracy of the cast product 7.
Moreover, in the casting die 1, the sliding die 4 includes the stopper 6 for locking the slider core 5 and the hydraulic cylinder 6c as the mechanism of moving the stopper 6.
According to the casting die 1 as described above, the freedom in design can be enhanced as compared with a casting die in the related art which requires a first movable core and a second movable core to be engaged with each other and positioned with high accuracy.
In addition, in the casting die 1 as described above, the stopper 6 at the locking position is located to put the rod 5b of the slider core 5 in contact with the inner sides of the bifurcate tips and is put in contact with the bottom surface 5a1 of the core body 5a.
With the casting die 1 as described above, the rod 5b of the slider core 5 is held from at least two directions, so that the stopper 6 can effectively lock the slider core 5 by preventing the slider core 5 from rattling.
Further, in the casting die 1 as described above, the bottom surface 5a1 of the core body 5a is positioned by the top surface 6a of the stopper 6.
The casting die 1 as described above can more reliably prevent the slider core 5 from displacing and tilting because the pressure of the molten metal applied to the slider core 5 is received by the surface. As a result, the casting die 1 can more reliably prevent the molten metal from being inserted between the dies. In the casting die 1, it is possible to prevent wear of peripheral components of the slider core 5 and even more increase its service life.
In the casting die 1 as described above, the contact surface of the stopper 6 with the bottom surface 5a1 of the core body 5a is inclined with respect to the movement direction D1 of the stopper 6.
According to the casting die 1 as described above, the sliding resistance between the stopper 6 and the bottom surface 5a1 of the core body 5a during the movement of the stopper 6 can be kept low. According to the casting die 1 as described above, the slider core 5 can be prevented from galling against the stopper 6 due to the molten metal pressure that the slider core 5 receives during casting. As a result, the casting die 1 makes it possible to more reliably prevent the slider core 5 from malfunctioning.
The casting method using the casting die 1 in the present embodiment includes the step of moving the stopper 6 and the step of locking the slider core 5 by the stopper 6.
According to the casting method as described above, it is possible to prevent the slider core 5 from displacing and thereby more reliably prevent the molten metal from inserting during casting.
In addition, after the cast product 7 is formed in the cavity C, this casting method includes the preliminary pushing step of pushing out the slider core 5 from the casting position and the core pull-in step of pulling back the slider core 5 into the sliding die 4.
According to the casting method as described above, the core pull-in step makes it possible to release the sliding dies 4 from the movable die 3.
Moreover, in this casting method, the damper base 15, which is the portion of the cast product 7, is slightly elastically deformed in the preliminary pushing step, so that a clearance can be formed between the slider core 5 (the core body 5a) and the damper base 15. As a result, the damper base 15 can be more easily released from the slider core 5.
Further, in this casting method, a casting pressure applied during the casting is applied to the stopper 6 after the casting via the bottom surface 5a1 of the slider core 5 (the core body 5a). In other words, the top surface 6a of the stopper 6 is strongly pressed against the bottom surface 5a1 of the core body 5a shown in
Meanwhile, in the casting method in the present embodiment, the load applied to the stopper 6 due to the casting pressure is released in the preliminary pushing step. Thus, in the casting method, the locking of the slider core 5 with the stopper 6 can be easily released. Furthermore, according to the casting method, since the stopper 6 can easily come off the slider core 5, it is possible to reliably prevent a failure of die release and deformation of the cast product 7.
According to the casting die 1 as described above and the casting method using this casting die 1, a cast product 7 is prevented from deforming or cracking in the course of die release, so that the cast product 7 with high shaping accuracy can be obtained, and such stable die release makes it possible to improve the maintainability and reduce the cycle time.
Although the present embodiment is described above, the present invention is not limited to the above embodiment, but may be carried out in various embodiments.
Number | Date | Country | Kind |
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2023-054500 | Mar 2023 | JP | national |