JP4178592B2 - Casting method of casting having insert member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a casting method in a case where an insert member excellent in mechanical properties such as wear resistance is cast on a base material in a cast product such as a light metal alloy.
[0002]
[Prior art]
In many devices, a cast product made of a light metal material such as an aluminum alloy or a magnesium alloy is used for weight reduction, and an insert member is cast in order to reinforce a part thereof.
The parts that cast this insert member include engine pistons, pulleys for rotational transmission, etc., but insert circular reinforcing ring grooves such as metal porous bodies and metal fiber molded bodies into base materials such as aluminum alloys. It is cast as a member to improve wear resistance and sag resistance.
[0003]
Also in the pulley for rotational transmission, etc., as shown in FIG. 12, in order to improve the wear resistance of the belt contact portion 4, an insert member 2 made of a steel material having excellent wear resistance is formed in an annular shape. In this way, the base material 3 is cast and cast, and a pulley with improved wear resistance is obtained that is light in weight and excellent in wear resistance.
Many insert members cast into these pistons, pulleys, etc. have a ring shape and a uniform thickness distribution in the circumferential direction, that is, a shape having the same cross section including the rotation center axis of the ring.
[0004]
The casting method for casting these insert members is the divided molds 10G, 10H, lower molds 12G, 12H concave grooves 13G as in the pulley casting methods shown in FIGS. After inserting the insert members 2G and 2H on the 13H and clamping them with the upper molds 11G and 11H and the lower molds 12G and 12H, the molten metal W is poured into the spaces 14G and 14H from the gates 15G and 15H (gravity casting). ) Or press-fitting (die casting).
[0005]
[Problems to be solved by the invention]
However, in this casting method, since the insert members 2G and 2H are simply placed in the concave grooves 13G and 13H, as shown in FIG. The insert member 2G is pushed upward by the molten metal pressure flowing into the space portion 14G, so that a deviation occurs from the position where it is initially placed. And there exists a problem that the quality deterioration of a cast product generate | occur | produces by disturbance of the flow of the molten metal produced by this shift | offset | difference.
[0006]
In particular, in the pulley for rotational transmission, the insert member has a complicated shape as shown in FIGS. 12 to 14, as proposed by the present inventors in Japanese Patent Application No. 9-269682. There are the following problems caused by this shape.
[0007]
That is, in the pulley 1 for rotational transmission, when the pulley 1 is formed of a light alloy such as aluminum, the belt contact portion 4 that requires wear resistance strength is formed by a steel material reinforcing member, and this reinforcement is performed. The member is insert-molded as the insert member 2, but when the pulley 1 is cast, a light metal material such as an aluminum alloy has a higher thermal expansion coefficient than the steel material, so that a difference occurs in the amount of shrinkage between the two during cooling, There is a tendency that the joining force at the joining portion becomes weak or the joining surface is peeled off and separated, and a strong rotational force is generated at the belt contact portion 4 of the pulley 1. Therefore, there is a possibility that the insert member 2 is loosened and loosened during use.
[0008]
Therefore, the insert member 2 proposed by the present inventors has a shape as shown in FIGS. 13 and 14, and is held by the light metal material portion 3 in the portion cast into the light metal material portion 3 of the insert member 2. A fitting support 20 is provided as an uneven portion, and this fitting support 20 is fixed to the outer peripheral direction fixing portion 21 that prevents the pulley from moving in the eccentric direction and to the rotation direction fixing that prevents the pulley from moving in the rotation direction. Part 22 is provided.
[0009]
When insert-molding such a ring-shaped insert member 2 having irregularities in the circumferential direction R, there is a concave portion 24 on the side surface of the insert member 2 or a convex portion 22 at the position where the pouring spout is located. As a result, the shape of the molten metal flow path near the gate is changed, so that the flow of the molten metal greatly changes even if there is a slight deviation in the circumferential direction.
[0010]
For this reason, when pouring is performed by the conventional casting method as shown in FIG. 11, deviation from the set position occurs, so that the flow of the molten metal cannot be maintained in an optimum state, and the quality of the cast product is reduced. As it gets worse, the amount of deviation is not constant, and there is a problem that the quality varies.
Therefore, in order to align the quality of the cast molded product having the ring-shaped reinforcing member having such irregularities at a high level, it is necessary to always keep the positioning in the circumferential direction of the insert member located at the gate, In the casting method of the prior art, there is a problem that it is impossible to perform positioning and prevention of misalignment around the axis of the ring of the insert member, that is, in the circumferential direction (arrow R direction).
[0011]
The present invention has been made to solve the above-described problems, and its purpose is to counter the axial and circumferential positioning of the ring-shaped insert member and the pressure of the molten metal flowing into the mold. It is possible to perform fixed support, prevent displacement of the installation position of the insert member with respect to the mold, and maintain the flow path of the molten metal flowing in from the pouring gate in an optimal and constant shape, so that a high-quality cast product can be obtained. It is an object of the present invention to provide a casting method of a cast product having an insert member that can be obtained and can prevent product variations.
[0012]
[Means for Solving the Problems]
The casting method of the cast product having the insert member for achieving the object as described above is a fixed support portion that protrudes from the outer peripheral portion to the outer peripheral portion of the insert member having a circular outer periphery to be cast into the base material of the cast product. And positioning the outer peripheral circle of the insert member in the axial direction by sandwiching the fixed support portion with the split surface of the mold during casting, and the fixed support portion and the split surface of the mold are the insert member The outer peripheral circle is meshed with each other in the direction around the axis to perform positioning in the direction around the axis , and the cast product is a pulley, the insert member is a belt contact portion of the pulley, and the base material And a fitting support portion having an outer peripheral fixing portion that prevents the pulley from moving in the centrifugal direction, and the fixed support portion is removed when finished .
[0013]
An engaging projection is formed as the fixed support portion, and an engaging concave portion that engages with the engaging projection is provided on at least one of the divided surfaces of the mold, so that the outer circumference of the insert member extends in the direction around the axis. Perform positioning.
Alternatively, as the fixed support portion, a flange portion having a first positioning engagement portion is formed on the outer periphery of the insert member, and the second engagement portion is engaged with the first positioning engagement portion on at least one of the divided surfaces of the mold. A hook holding portion having a positioning engagement portion is provided to position the outer peripheral circle of the insert member in the direction around the axis.
[0014]
That is, a fixed support portion such as an engaging protrusion or a collar portion that is removed when the cast product is finished protrudes from the outer peripheral portion of the insert member on the outer peripheral portion of a ring-shaped insert member whose outer periphery is a circular shape such as a cylinder or a cone. By fixing the fixing support portion with a mold, positioning in the direction around the axis of the outer peripheral circle of the insert member, that is, the rotation direction (R direction) of the ring is performed at the same time.
[0015]
When the mold is plastic such as a sand mold, the insert member is fixed to the mold by pressing the insert member having the fixed support portion, and the mold is already molded such as a mold. In this case, an engagement recess or a hook holding portion is provided in advance on the dividing surface portion of the mold, and the insert member is sandwiched between the dividing surface portions of the mold, so that not only in the axial direction (X direction) but also around the shaft. The direction (R direction) is also positioned and fixedly supported to give a restraining force to the molten metal pouring pressure during casting.
[0016]
This fixed support part is only required to be able to be positioned and fixedly supported, and has a plurality of convex engagement protrusions and a flange part basically provided on the entire periphery of the insert member. Alternatively, a part of the collar provided on the entire circumference can be formed into a thin and thick uneven shape.
Therefore, since the positioning and fixing means are provided not only in the axial direction between these insert members and the mold but also in the direction around the axis, the position of the insert member is fixed with respect to the gate, and the flow path is Since the state can be kept constant and the pouring state of the pouring can be made the same, the quality variation between products is prevented.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the casting method according to the present invention, the target cast product is particularly suitable for the insert member having a complicated shape as illustrated in FIGS. 12 to 14. It can also be applied to insert members. The complicated shape of the insert member 2 shown in FIGS. 12 to 14 increases the joining force of the joining surface with the base material 3 as described above, resulting in a strong rotational force acting on the belt contact portion 4 such as the pulley 1. This is also to prevent the looseness and peeling during use.
[0018]
The pulley 1 is formed by placing the insert member 2 in the mold 10 when the pulley 1 is cast, and casting the insert member 2 when the molten aluminum alloy is poured into the mold 10. The base material 3 of the pulley 1 is formed of a light metal material such as an aluminum alloy such as an Al—Si—Mg based casting material, and the annular insert member 2 is formed of a steel material such as a chromium molybdenum steel material. The
[0019]
In this insert member 2, a fitting support portion 20, which is an uneven portion gripped by the base material 3 of the light metal material portion, is provided in a portion that is cast into the base material 3 of the light metal material portion of the insert member 2. The fitting support portion 20 has an outer peripheral direction fixing portion 21 for preventing the pulley 1 from moving in the centrifugal direction P and a rotation direction fixing portion 22 for preventing the pulley 1 from moving in the rotation direction R, and is ring-shaped. The shape has irregularities in the direction around the axis (R direction).
[0020]
In the casting method according to the present invention, a fixed support portion 26B that is removed by machining such as cutting when finished is provided on the outer peripheral portion of the insert member 2 shown in FIG. 11 as in the insert member 2B shown in FIG. .
Next, the structure of the insert member 2B having the fixed support portion 26B and the mold 10 will be described. In FIG. 1, instead of the insert member 2B having a complicated shape shown in FIG. 3, the insert member 2A having a simplified shape is used in place of the insert member 2B. This corresponds to the fixed support portion 26B.
[0021]
As shown in FIGS. 1 and 2, the dividing surface of the casting mold 10 is arranged on a portion where the insert member 2A is placed, so that the insert mold 2A can be easily inserted and positioned in the lower mold 12, and the lower mold 12 An engaging recess, which is a groove-shaped holding portion 16 for fitting and supporting an engaging protrusion 26A, which is a fixed support portion, is formed in the insert member 2A by fitting the fixed support portion 26A to the holding portion 16. The ring is positioned and fixed in the direction around the axis (R direction).
[0022]
The holding portion 16 that engages and holds the fixed support portion 26A is provided in the lower mold 12 of the mold having the divided surface in FIGS. 1 and 2, but the upper mold 11 or the lower mold of the mold having the divided surface. It may be provided on at least one of 12 and may be on one side or both sides.
Then, by placing the upper mold 11 on the lower mold 12 and fixing it, the fixing support portion 26A is sandwiched between the upper mold 11 and the lower mold 12 so that positioning and fixing in the vertical direction, that is, the axial direction (X direction) is performed. Do.
[0023]
By these fitting and clamping, the insert member 2A is positioned and held at the divided portion of the mold 10 , and a restraining force is given to the fluid force acting on the insert member 2A when the molten metal flows during pouring. Next, the fixed support portion and the holding portion will be described in detail. As shown in FIGS. 1 to 4, the fixed support portion is formed by engaging protrusions 26A, 26B, and 26C protruding from the outer peripheral portions of the insert members 2A, 2B, and 2C, and the holding portion 16 provided on the mold 10 side is The engaging protrusions 26A, 26B, and 26C can be formed by engaging recesses as shown in FIGS.
[0024]
Alternatively, as shown in FIG. 5, the fixed support portion is formed by a flange portion 26D of an annular disk projecting from the outer peripheral portion of the insert member 2D, and the first positioning engagement portion is formed by a cut portion formed in the flange portion 26D. A notch 27a is formed, and the second positioning engaging part is formed by a protrusion 17a that engages with the notch 27a. Further, as shown in FIG. 6, the first positioning engagement portion can be formed by a convex portion 27b provided in the flange portion 26E or a concave portion 27c provided in the flange portion 26F, and the first positioning engagement portion is provided in the upper molds 11E and 11F. The two positioning engaging portions can also be formed by the concave portions 17b and the convex portions 17c that engage with the convex portions 27b and the concave portions 27c, respectively.
[0025]
That is, the fixed support portion 26, the first positioning engagement portion 27, and the second positioning engagement portions 16 and 17 may be any one that can be positioned and can be fixedly supported. A plurality of convex engaging projections 26A, 26B, and 26C, an annular flange portion 26D that is basically partly cut out, or a portion of the flange portions 26E and 26F that are provided on the entire periphery. Can be formed by forming a concavo-convex shape with a wall thickness 27b and a wall thickness 27c, or by providing a positioning hole (not shown). Then, the holding portion 16 and the second positioning engagement portion 17 of the mold side is formed by the engageable recess 17b and the convex portion 17c to the first positioning engaging portion 27 of the engaging recess and respectively.
[0026]
According to the above casting method, since the positioning and fixing means are provided not only in the axial direction X between these insert members 2A to 2D and the mold 10 but also in the axial direction R, the insert member Since the position of 2A to 2D can be precisely set and can be fixed so as not to be misaligned, the shape of the flow path in the mold 10 can be kept constant. Since the inflow state can be made the same, quality variation between products can be prevented.
[0027]
【The invention's effect】
As described above, according to the casting method of the cast product having the insert member according to the present invention, the fixed support portion protruding from the outer peripheral portion of the insert member is provided, and the fixed support portion removed at the time of finishing is divided into the molds. Since it is engaged with the surface part and held and held, the axial direction of the insert member and the direction around the axis, that is, the circumferential direction of the outer peripheral portion can be accurately positioned with respect to the mold, and it is securely fixed. it can.
[0028]
Therefore, it is possible to prevent the displacement of the installation position of the insert member caused by the pouring pressure, always maintain the positional relationship of the insert member with respect to the pouring gate, and maintain the optimum flow of the molten metal flowing from the pouring gate. Therefore, each cast product can be cast in the same state.
In addition, since the molten metal flow can be prevented from being disturbed during the pouring caused by irregular displacement of the insert member, it is also possible to prevent the deterioration of the internal quality of the casting, and the cast material of the high quality insert member can be produced. It becomes possible to manufacture a cast product.
[0029]
Therefore, a cast product having a high-quality insert member can be obtained, and variations in products can be prevented.
[Brief description of the drawings]
FIG. 1 is an exploded view including a partial cross-sectional shape showing an insert member and a mold for explaining a casting method according to the present invention.
2 is a side sectional view of the insert member and mold of FIG. 1 assembled. FIG.
FIG. 3 is a perspective view showing an example of an insert member for a pulley related to the present invention.
FIG. 4 is a perspective view showing an example of the shape of an insert member according to the present invention.
FIG. 5 is a perspective view showing another example of the shape of the insert member according to the present invention.
6A and 6B are cross-sectional views showing examples of the engaging portion of the insert member according to the present invention, in which FIG. 6A is a diagram of a convex shape, and FIG. 6B is a diagram of a concave shape.
FIG. 7 is an exploded view including a partial cross-sectional shape showing an insert member and a mold for explaining a conventional casting method.
8 is a side sectional view of the insert member and the mold of FIG. 7 assembled. FIG.
FIG. 9 is an exploded view including a partial cross-sectional shape showing an insert member and a mold for explaining another casting method of the prior art.
10 is a side sectional view of the insert member and mold of FIG. 9 assembled. FIG.
FIG. 11 is a side sectional view of a mold for explaining a problem of a conventional casting method.
FIG. 12 is a side sectional view of one half of a transmission pulley using an insert member.
FIG. 13 is a perspective view showing a fitting support portion of an insert member of a transmission pulley.
14 is a perspective view of the insert member of FIG. 13. FIG.
[Explanation of symbols]
1 Pulley 2A, 2B, 2C, 2D, 2G, 2H Insert member 3 Light metal material part (base material)
4 Belt contact part
10, 10G, 10H mold
11, 11G, 11H, 11E, 11F Upper mold
12, 12G, 12H Lower mold
13, 13G, 13H Groove
14, 14G, 14H Space
15, 15G, 15H
16 Engaging recess (holding part)
17a, 17b, 17c Second positioning engagement part
20 Mating support
21 Peripheral direction fixing part
22 Rotation direction fixing part
24 recess
26A, 26B, 26C Engaging protrusion (fixed support)
26D, 26E, 26F collar (fixed support)
27a, 27b, 27c 1st positioning engagement part

Claims (3)

By providing a fixed support portion projecting from the outer peripheral portion on the outer peripheral portion of the insert member having a circular outer periphery to be cast into the base material of the cast product, the fixed support portion is sandwiched by the dividing surface of the mold during casting. Positioning in the axial direction of the outer peripheral circle of the insert member is performed, and the fixed support portion and the dividing surface of the mold are engaged with each other in the direction of the outer peripheral circle of the insert member. And the casting is a pulley, the insert member is a belt contact portion of the pulley, and an outer peripheral direction fixing portion that fits with the base material and prevents the pulley from moving in the centrifugal direction. A casting method for a cast product having an insert member , wherein the fixed support portion is removed when finished .   An engagement projection is formed as the fixed support portion, and an engagement recess that engages with the engagement projection is provided on at least one of the dividing surfaces of the mold, thereby positioning the outer circumference of the insert member in the direction around the axis. The casting method for a cast product having an insert member according to claim 1, wherein the casting method is performed.   A second positioning member that forms a flange having a first positioning engagement portion on the outer periphery of the insert member as the fixed support portion and that engages the first positioning engagement portion on at least one of the divided surfaces of the mold. The casting method for a cast product having an insert member according to claim 1, wherein a flange portion having a joint portion is provided to position the outer peripheral circle of the insert member in the direction around the axis.

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