JPH11179522A - Cast-in casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a position precision of an insert member by forming a pair of annular projecting parts with extending both side faces of an opening part of an insert member is an outer diameter direction and fitting-holding a projecting part of the insert member to a fixed part protruding into a mold. SOLUTION: In a small ring 40 (insert member) and a large ring 50 (insert member), a member forming a V shaped groove part 3 is extended in an outer diameter direction to form projecting parts 44, 54. The small ring 40 (insert member) and a large ring 50 (insert member) are subjected to aluminizing treatment. An annular fixed part 7 engaging the projecting parts 44, 54 is arranged to a mold 13a. A first die member 12, a second die member 13a and a third die member 15 are die assembled. A cast-in formed part is obtained by pouring a molten aluminum. The cast-in formed part is cut to remove the projecting parts 44, 54, thus a finished part is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting insert members of dissimilar metal parts such as steel into light metal castings such as pulleys and pistons.

[0002]

2. Description of the Related Art In the manufacture of a lightweight crank pulley attached to an engine of an automobile or the like, a main body is cast from a light metal material such as aluminum or an aluminum alloy in order to promote a reduction in weight, but a belt comes into contact therewith. The part with severe wear is formed of an iron-based metal member with excellent abrasion resistance (molded to-be-filled material), and this insert member is held at a predetermined position in the mold to be formed of a light metal material such as aluminum. It is cast in metal and integrated.

[0003] The process of this cast-in-place casting will be briefly described. For example, even if an insert member made of polished steel is directly cast-in, the bondability with a light metal material is poor and separation is easy. Is subjected to an aluminized treatment. As a pre-treatment of the aluminized treatment, the insert member is immersed in a degreasing solution such as an alkali degreaser or acetone to immerse the insert member in a degreaser containing sodium hydroxide or the like to perform a solvent degreasing treatment. Is immersed in a molten aluminum melted at about 730 ° C. for a predetermined time to perform an aluminized treatment.

[0004] Next, casting is performed. The mold is formed by molding sand, the mold is preheated by a gas burner, dried, and then assembled. At the time of this mold assembly, the aluminized insert member is placed at a predetermined position in the mold. Then, a molten metal such as molten aluminum at about 740 ° C. is poured into the completed mold set, the molten metal is poured, and after cooling and mold dispersion are performed, a molded product is taken out and complete casting is completed.

FIG. 4 shows an example of a light-weight crank pulley used for an automobile engine or the like as an example of this type. First, the first mold member 12 is disposed on a base plate (not shown), and then the two small mold members 13a, 13b sandwich the small rings 40, 40 and the large ring 50 as insert members from both sides. Then, the second mold members 13a and 13b are positioned on the dies 14a and placed on the first mold member 12. Further, a third mold material 15 having a zircon sand 16 applied to a portion abutting on the inside of the lightweight crank pulley 1 is positioned and placed with lumps 14b and 14c to form a mold. In this mold assembly, the portion indicated by arrow X is the feeder position. In addition, in order to control the local cooling rate of the molten metal, cold gold 18 is appropriately arranged.

In the prior art, when performing the insert casting in the above-described process, a ring-shaped, disk-shaped, or cylindrical insert member 40, 50 having a groove 3 in the outer peripheral portion in the circumferential direction is used as a mold. 5, the inside of the groove 3 of the insert member 40, 50, ie, the groove 3
The tip 13 of the mold 13a is brought into contact with the support portion 5 having a round cross section on the inclined surfaces 42, 42 or 52, 52 of the insert members 41, 42.
Positioning and support.

The groove 3 is supported on the inclined surfaces 42, 42 or 52, 52 because the aluminum base material 2 is cast outside the groove 3 so that there is no other suitable supporting portion.

[0008]

However, in the case where an aluminum alloy is used for the cast-in material, that is, the base material 2, in order to improve the bonding strength between the insert members 40, 40, 50 and the base material 2, an insert is required. Since the members 40, 40, and 50 are subjected to the aluminized treatment, the aluminum used for the aluminized treatment is at a high temperature.
Thermal deformation occurs in the groove portions 40, 40, and 50, and a deviation occurs in the inclination angle of the groove portions 3. In particular, since the inclined surfaces 42, 42 or 52, 52 on both sides forming the groove portion 3 are press-formed, when heat is applied, the residual stress is released, so that the surface is unstable, and the heat deformation may occur. easy.

For this purpose, the deformed insert member
When the inclined surfaces 42, 42 or 52, 52 of the groove portions 40, 40, 50 are abutted and supported by the distal end portion having a round cross section of the supporting portion 5, the other portion, that is, the inclined portion, comes into point contact in a cross sectional view. If the inclination angle is increased or decreased due to thermal deformation of the surfaces 42, 42 or 52, 52, a positioning error between the insert members 40, 40, 50 and the mold 13a increases, and accurate positioning can be performed. become unable. As a result, as shown in FIG. 6, there is a problem that the sinking A occurs in the insert member 50, the axes of the insert members 40 and 40 are eccentric B and B ', and an axial deviation D occurs.

[0010] In particular, when a plurality of insert members 40, 40 are cast, eccentricity and positional deviation in the axial direction tend to occur between the insert members 40, 40, and the mold assembly process is complicated due to the correction. . Therefore, during the casting, the temperature distribution of the insert member becomes uneven and unevenness occurs, and the temperature control becomes difficult, so that the quality of the cast product deteriorates. Therefore, the number of defective products increases, the product yield decreases, and the cost is reduced. There is a problem that products cannot be supplied.

Furthermore, in order to facilitate the placement of the insert member in the mold, it is necessary to provide a clearance as a fitting allowance between the insert member and the mold. If the clearance is increased in consideration of the change in advance, there is a problem in that the insert member has a large amount of slack, eccentricity, and axial displacement.

Further, if the arrangement of the insert members is displaced, it becomes difficult to maintain a balance around the rotation axis, and when used at a high rotation speed, uneven rotation or damage to the rotation axis occurs, so that normal operation cannot be performed. Also occurs. In addition, in order to avoid these problems, if the thickness of the insert member is increased to prevent thermal deformation of the insert member, there is a problem that the weight of the product increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to improve the positioning accuracy of a casting position of an insert member, thereby enabling casting of a highly accurate product and positioning. An object of the present invention is to provide a cast-in-place casting method capable of simplifying the operation and improving the efficiency of the mold assembly operation.

[0014]

In order to achieve the above object, a cast-in-place casting method comprises a step of forming a groove along a circumferential direction of an outer peripheral portion, such as a ring, disk, or cylinder. In a method of casting by inserting a body-shaped insert member, a member forming both side surfaces of the opening of the groove is extended in an outer radial direction to form a pair of annular protrusions, and a mold is formed. A fixing portion for engaging the protrusion with the outer surface is formed in the protrusion, and the fixing portion is fitted and clamped to the protrusion of the insert member, and the insert member is arranged at a predetermined position in the mold. This is a casting method in which the entire mold is assembled, and molten metal is poured into the assembled mold and cast.

[0015] Then, the protruding portion of the insert product is removed by cutting after insert casting. In the casting method of casting the insert member, an annular protrusion is formed, which is easy to hold on the insert member, hardly deformed by heat, and keeps good positioning accuracy, and this protrusion is fixed to the fixed portion in the mold. Since the insert member is positioned at a predetermined position in the mold by supporting the fitting, accurate positioning can be performed,
Further, the work is simplified, so that the work efficiency is improved.

That is, since the insert member is press-molded, residual stress remains in the groove after the press molding, and the residual stress is released when heat is applied during aluminized processing or pouring. Therefore, it is easy to be thermally deformed, and the inclination angle of the groove is easily changed by the thermal deformation. On the other hand, since the annular flat protruding portion does not generate the residual stress and has a small amount of thermal deformation in the thickness direction, if the protruding portion is held on the annular flat surface, positioning can be performed with high accuracy.

Further, in particular, when the groove of the insert member has a cross section V
This casting method is particularly effective in the case of a groove-shaped structure having a U-shape and a portion held by the mold having only an inclined portion. Further, when a plurality of the insert members are cast, the side surfaces of the protrusions are joined together to be integrated, and then the fixing portion is fitted and clamped to the protrusions of the insert member, thereby forming the inside of the mold. If the insert member is arranged at a predetermined position and the entire mold is assembled and cast, the work of individually positioning the insert members can be omitted, so that the step of attaching the insert member to the mold is simplified.

Furthermore, by integrating the insert member,
Since there is no occurrence of eccentricity or displacement between the insert members, the insert members can be accurately arranged in the mold. This insert casting method can also be used when the molten metal is aluminum or when a molten metal other than aluminum, such as magnesium, zinc, or an alloy thereof, is used as an insert material (base material). Further, the present invention can also be applied to casting using a sand mold or a mold, die casting, or the like.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cast-in-place casting method according to the present invention will be described with reference to the drawings, taking a lightweight crank pulley used for an automobile engine or the like as an example. The molded product of this lightweight crank pulley 1 is as shown in FIG. 2, and the groove 3 at the portion where the belt contacts is SP
Insert member 40 made of only CC material and wrought steel,
40, 50 are formed. These insert members 40,
As shown in FIG. 3, reference numeral 50 denotes a ring-shaped substantially rotating body, and the groove 3 has a V-shaped cross section.

Then, the insert member 40 which is a small ring
In the case of the two ring members 41a and 41b or 41c
41d are back-to-back and joined by a welded portion 46, and a pair of V-shaped grooves 3 are formed along the circumferential direction of the outer peripheral portion. The groove 3 is formed on the outer periphery of the insert member 40.
Members forming both side surfaces of the opening portion, that is, side surface portions 43, 43
Are extended in the outer diameter direction to form a pair of annular projections 44. That is, the pair of annular projecting portions 44, 44 are formed so as to project perpendicular to the rotation axis C1 of the insert member 40.

Further, two insert members 40,
The 40 adjacent ring members 41b and 41c are joined and integrated by a welded portion 45 in the projection 44 to form an insert member 4 having two V-shaped grooves 3. Similarly, as shown in FIGS. 1 and 2, the insert member 50 of the large ring has two ring members 51a and 51b joined by a welded portion 56, and a set of V-shaped grooves 3 is provided on the outer peripheral portion. Has formed. Similarly to the insert member 40 of the small ring, members forming both side surfaces of the opening of the groove 3, that is, side surfaces 53, 53 are extended in the outer diameter direction on the outer periphery of the insert member 50 to form an annular 1. Protrusions 54, 54 having a pair of flat surfaces are provided.

Here, two ring-shaped members 51a, 51b
Are formed by welding to form one insert member 50.
May be used. And these insert members 4,
Even if the 50 is cast as it is, the bondability with the light metal material as the base material 2 is poor and it is easy to separate. Therefore, an aluminized process is performed to improve the bondability.

As a pretreatment, the insert members 4 and 50 are immersed in a degreasing solution containing sodium hydroxide or the like as a main component to carry out alkali degreasing, washed with water, and further immersed in a degreasing solution such as acetone to form a solvent. After performing a degreasing treatment and further removing the degreasing solution by wiping or the like, the insert members 4 and 50 are dried at about 100 ° C. so as not to oxidize. The surface-treated insert members 4 and 50 are aluminized so as to be compatible with an aluminum base material when an aluminum alloy casting is made. This process is performed by supporting the insert members 4 and 50 with a support member. In the molten aluminum around ℃,
After forming a reaction layer having a predetermined thickness by immersing for a predetermined time, the surplus molten aluminum is removed.

Next, the process moves to a casting process.
In order to fit and hold the above-mentioned insert members 4 and 50, a ring-shaped fixing portion 7 that engages with the outer surface of the projecting portion 44 is provided in the casting molds 13a and 13b. Then, as shown in FIG. 4, when assembling the molds 12, 13a, 13b, and 15, the fixing portion 7 is inserted into the projecting portions 44 and 54, and the insert members 4 and 50 are formed into a semicircular shape. Two divided molds 13a and 13b
And placed in a predetermined position, and the entire mold 12, 13
Assemble a, 13b and 15.

After the mold is assembled, molten aluminum is poured and cast, and after the casting, cooling and mold dispersion are performed to take out a cast-in molded product. The protrusions 4 of the insert members 4 and 50
4 and 54 are extra, so this cast-in molded product is set in a cutting machine and removed by cutting to obtain a finished product.
This cutting is performed by the protrusions 44, 54 of the insert members 4, 50.
In addition to shaving off, the cutting is performed to the E line and the F line in FIG. 2, and further, a part of the groove 3 of the insert members 4 and 50 is cut and shaped by this cutting.

According to this cast-in-place casting method, in the casting method in which insert members 40 and 50 made of steel or the like are cast-out, projections 44 and 54 are provided at positions where positioning and holding are easy. Since the fixing portion 7 in the mold is fitted and clamped at 54, the positioning can be performed accurately, and the positioning precision can be improved. Further, the protrusions 44 and 54 are fixed to the fixing portions 7 in the mold.
Since the positioning and fixing can be performed only by fitting into the device, the positioning operation can be simplified and the operation efficiency can be improved.

The reason why the positioning accuracy is improved will be described in more detail as follows. This insert member 40, 50
Since the ring members 41a, 41b, 41c, 41d, 51a, and 51b are press-formed, residual stress remains in the groove 3 after press-forming, and this residual stress is generated by heat during aluminized processing or pouring. It is released when heat is applied and is thermally deformed.

The inclined surface forming the groove 3 by this thermal deformation
The inclination angle of 42 and 42, 52 and 52 varies, but the annular projection
Since no residual stress is generated in the projections 44 and 54 and the amount of thermal deformation in the thickness direction is small, if the projections 44 and 54 are held by the annular flat surfaces, positioning can be performed accurately. And in this mold assembly, the insert members 4 and 50
Instead of the inclined surfaces 42, 52 in the groove 3, the insert member 4,
The fixed portion 7 is supported by the protrusions 44 and 54 which are flat surfaces perpendicular to the 50 rotation axis C1. That is, since the positioning is performed by engaging the fixing portion 7 having a surface perpendicular to the center axis C of the mold assembly, the insert members 4 and 50 can be supported by the engagement between the planes perpendicular to this axis. , Positioning accuracy can be increased.

Further, when a plurality of insert members 40, 40 are cast, the side surfaces of the projections 44, 44 are joined together by a welded portion 45 to be integrated, and then the welded projections 44, 44 are joined together. Since the insert member 4 is held at a predetermined position by fitting and holding the fixed portion 7 of the mold with the other welded portions 44, 44, the work of attaching the insert members 40, 40 to the molds 13a, 13b can be simplified. In addition, eccentricity and misalignment between the insert members 40, 40 can be prevented at the same time.

[0030]

As described above, according to the cast-in-place casting method according to the present invention, in the casting method in which the insert member having a substantially rotary body shape such as a steel material and having a groove is cast-out, A pair of annular protrusions are formed by extending both side portions of the opening of the groove, and the fixed portions formed in the mold are fitted and sandwiched by the protrusions so as to be positioned at predetermined positions in the mold. Since the insert member is positioned at a position, the positioning can be accurately performed. In addition, since positioning and fixing can be performed only by inserting the fixing portion in the mold between the projecting portions, the mold assembling operation can be simplified and the operation efficiency can be improved.

In particular, in the case where the groove has a V-shaped cross section and the portion to be held by the mold has only an inclined portion which is easily deformed by heat, this cast-in casting method is particularly effective. Further, when a plurality of insert members are cast, the side surfaces of the projecting portions are joined and integrated, and then the fixing portion is fitted and clamped to the projecting portion of the insert member, and the insert member is placed at a predetermined position in the mold. Is arranged and the entire mold is assembled and cast, so that the process of attaching the insert member to the mold can be simplified, and at the same time, eccentricity and positional deviation between the insert members can be prevented.

Therefore, the position of the insert member can be accurately determined at the time of cast-in casting, and the mold assembling operation can be simplified, so that a lightweight and inexpensive aluminum cast product can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a mold showing a method for holding an insert member according to the present invention.

FIG. 2 is a front view of a lightweight crank pulley partially shown in section.

3A and 3B are views showing an insert member of the lightweight crank pulley, wherein FIG. 3A is a front view, and FIG. 3B is a side view in partial cross section.

FIG. 4 is a sectional view of a mold configuration showing an example of insert casting.

FIG. 5 is a partial sectional view of a mold showing a conventional method for holding an insert member.

FIG. 6 is a partial cross-sectional view of a mold for explaining a drawback in a conventional method for holding an insert member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Lightweight crank pulley (casting) 2 Molten metal (cast-filled base material) 3 Groove part 4 Integrated small ring 5 Support part 7 Fixed part 12 1st type | mold material 13a, 13b 2nd
Die 14a, 14b, 14c Dama 15 Third die 16 Zircon sand 18 Cold gold 40 Small ring (insert member) 41a, 41b, 41
c, 41d Ring member 42 Inclined surface 43 Side surface portion 44 Projected portion 45, 46 Welded portion 50 Large ring (insert member) 51a, 51b Ring-shaped member 52 Inclined surface 53 Side surface portion 54 Projected portion 55, 56 Welded portion

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenichiro Mine 3- 25-1, Tonomachi, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Isuzu Motor Co., Ltd. Kawasaki Plant (72) Inventor Suguru Liu Eighteen shelves in Fujisawa-shi, Kanagawa Prefecture Isuzu Motors Corporation Fujisawa Plant (72) Inventor Nobuaki Shinya 3-25-1 Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Isuzu Motors Corporation Kawasaki Plant (72) Inventor Masami Ueno 3 Tonomachi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture No. 25-1, Isuzu Motors Corporation, Kawasaki Plant (72) Inventor Naomi Nishi 3--15-1, Sotokanda, Chiyoda-ku, Tokyo Ryobi Co., Ltd., Tokyo Head Office (72) Inventor Makoto Nitta Chiyoda-ku, Tokyo 3-15-1, Sotokanda Ryobi Co., Ltd. Tokyo Head Office

Claims (3)

[Claims] 1. A method of casting an insert member having a substantially rotary body shape such as a ring shape, a disk shape or a cylindrical shape in which a groove portion is formed along a circumferential direction of an outer peripheral portion by casting and casting. The members forming both side surfaces of the insert are extended in the outer diameter direction to form a pair of annular protrusions, and a fixing portion for engaging the protrusions with the outer surface is formed in the mold so as to protrude, and the insert is formed. The fixing portion is fitted to the projecting portion of the member, and the insert member is arranged at a predetermined position in the mold to assemble the entire mold. The molten metal is poured into the assembled mold and cast. Cast-in casting method. 2. The device according to claim 1, wherein the groove has a V-shaped cross section.
The described insert casting method. 3. When a plurality of the insert members are inserted, the side surfaces of the projecting portions are joined and integrated,
3. The casting according to claim 1 or 2, wherein the fixing portion is fitted and clamped to the projecting portion of the insert member, the insert member is arranged at a predetermined position in the mold, and the entire mold is assembled.
The stuffed casting method according to 1.