JPH11291018A - Mold for inserting as cast-in - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for inserting as cast-in which can improve melt- sticking ratio of a member to be inserted. SOLUTION: This mold 9 for inserting as cast-in, is provided with a cavity 13 for casting a structural member composed of a member body and the member 8 to be inserted melt-stuck to the member body and having a zone 16 for setting the member to be inserted, a heating chamber 25 faced to non-melt-sticking surface at the reverse side of the melt-sticking surface 20 in the member 8 to be inserted and plural communicating grooves 261 -263 for supplying molten metal into the heating chamber 25 from the cavity 13. These communicating grooves 261 -263 are disposed so as to face to mutually facing both outer surfaces 21, 22 existing between the melt-sticking surface 20 and the non-melt-sticking surface 23 of the member 8 to be inserted. In this way, the member 8 to be inserted can be heated from the melt-sticking surface 20 side, non-melt-sticking surface 23 side and both outer surfaces 21, 22 sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-in mold used for casting a structural member consisting of a member body and a to-be-filled member welded to the member body.

[0002]

2. Description of the Related Art The applicant of the present invention has previously attempted to introduce a part of molten metal during casting into a non-welding surface side of a stuffed member and heat the stuffed member from the welding surface side and the non-welding surface. A cavity for forming a structural member having an area for installing a to-be-stuffed member, a heating chamber facing a non-welding surface of the to-be-molded member opposite to the welding surface, and supplying molten metal from the cavity to the heating chamber. Japanese Patent Laid-Open Publication No. Hei 8-257737 proposes a mold for insert molding having a communication groove.

[0003]

The cast-in mold is used, for example, for casting a camshaft for an internal combustion engine. A cast-to-be-molded material is welded to a base circle portion of a cam to form a nose portion. I do. In this case, when the temperature of the molten metal is constant, if the volume of the heating chamber is increased, the welding rate of the to-be-stuffed member is correspondingly increased. Causes a malfunction.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a mold for stuffing which is capable of suppressing an increase in the volume of a heating chamber and increasing the welding rate of a stuffed member to be cast. And According to the present invention, in order to achieve the above object, in order to cast a structural member including a member main body and a cast-to-be-molded member welded to the member main body, a structural member forming section having a cast-to-be-filled member installation area is provided. Cavity and
A casting chamber having a heating chamber facing a non-welding surface on a side opposite to a welding surface of the to-be-stuffed member, and a communication groove for supplying molten metal from the cavity to the heating chamber; And a plurality of the communication grooves, wherein the communication grooves are provided between the welding surface and the non-welding surface of the to-be-molded to-be-molded member so as to face both opposing outer surfaces. .

When the communication grooves are arranged as described above, a part of the molten metal on the welding surface side flows into the heating chamber through the communication grooves without stagnating there. Heating not only from the non-welded surface side, but also from both outer surface sides, the temperature can be raised quickly and sufficiently, and the high temperature state can be maintained for a predetermined time. Thereby, even if the increase in the volume of the heating chamber is suppressed, it is possible to improve the welding rate of the to-be-stuffed member. In this case, for example, two communication grooves facing one outer surface and one communication groove facing the other outer surface are arranged so as to be shifted from each other so as not to face each other. The two heating regions on the welding surface of the to-be-stuffed member by the two adjacent communication grooves are partially overlapped with each other, and the two heating regions and the heating region by the communication groove on the other outer surface side are formed. Partial overlap can be achieved, and thereby, the cast-in member can be sufficiently heated with a small number of communication grooves to increase the welding rate.

[0006]

1 and 2, a camshaft (structural member) 1 for an internal combustion engine includes a plurality of journals 2, a plurality of shaft portions 3 and a plurality of cams 4 arranged along the axial direction. A camshaft main body (member main body) 6 having a base circular portion 5, a plurality of crescent-shaped sintered bodies 8 as a to-be-molded toy member which is welded to the base circular portion 5 of each cam 4 and forms a nose portion 7; Consisting of

The camshaft body 6 is made of, for example, an alloy cast iron having good machinability and high toughness. The sintered body 8 is made of, for example, a particle-dispersed alloy cast iron having high hardness and excellent wear resistance. Be composed.

The camshaft 1 is manufactured through a stuffing process, a hanging process and a machining process using a shell mold 9 as a mold and a plurality of sintered bodies 8 shown in FIGS.

[0009] In FIG. 3, the shell mold 9 consists of first, second type 10 _1, 10 ₂ of the split, both types 10 _1, 1
0 camshaft molding cavity (structural member-molding cavity) by combining the _two mating surfaces 11, 12 1
3 is formed. The gate 14 communicates with the upper end of the cavity 13.

As clearly shown in FIGS.
In each of the cam forming regions 15 of No. 3, the crescent-shaped sintered body 8 constituting the nose portion 7 is installed in the nose portion-corresponding area (area for setting the to-be-stuffed member) 16. Referring also to FIG. 9, in the sintered body 8, the concave arc-shaped inner peripheral surface 18 facing the base circular portion forming area 17 and both end surfaces 19 connected thereto are welding surfaces 20, and are located on the opposite side of the welding surface 20. The convex outer peripheral surface is the non-welded surface 23. Opposite crescent-shaped outer surfaces 21, 2 located between the welding surface 20 and the non-welding surface 23
Reference numeral 2 denotes a contact surface with the shell mold 9. A barrier layer 24 is formed on the non-welded surface 23 and the outer surfaces 21 and 22 by using a resin-coated sand to prevent the molten metal from being welded thereto.

A heating chamber 25 is formed in the shell mold 9 so as to face a top portion of the non-welding surface 23 and both side portions thereof via a barrier layer 24. Further the shell mold 9, the communicating groove 26 _{1-26 3} more supplying molten metal to the heating chamber 25 from the cavity 13 is formed. One communicating groove 26 ₁ is disposed so as to face the outer surface 22 of the lower, of the two communication grooves 26 _2, 26 ₃ is arranged to face the upper side of the outer surface 21.

The lower communication groove 26 ₁ is formed so that the sintered body 8 is divided into two equal parts, from the shaft part forming area 27 immediately below the base circular part forming area 17 to the base circular part forming area 17 and the nose part. It extends through section 16 to heating chamber 25.
The bottom surface of the communication groove 26 _1, small projections 28 ₁ of the cross section chevron is formed so as to intersect with the longitudinal direction thereof. The small projections 28 ₁ the lower edge of the concave arc-shaped inner peripheral surface 18 of the sintered body 8, ridgeline i.e. the inner peripheral edge of the barrier layer 24 is disposed so as to face.

As shown in FIG. 7, the upper communication grooves 26 ₂ and 26 ₃ are located at both ends of the sintered body 8 so as to form the base circular portion forming area 17 and the nose corresponding area 1.
6 to the heating chamber 25. Each communication groove 26 ₂ ,
26 ₃ of the bottom, cross-sectional chevron small ridges 28 ₂ are formed so as to intersect with the longitudinal direction thereof. The small ridge 28 ₂
Are arranged such that the ridge line intersects the upper edge of the concave arc-shaped inner peripheral surface 18 of the sintered body 8, that is, the inner peripheral edge of the barrier layer 24.
Thereby, as clearly shown in FIG. 8, the two communication grooves 26 ₂ and 26 ₃ facing the upper outer surface 21 and the lower outer surface 22
Are arranged in a staggered manner so as not to be opposed to _one communication groove 261 facing the other.

In the shell mold 9 having the above-described configuration, when a molten metal having an alloy cast iron composition is poured into the cavity 13 from the gate 14, the molten metal flows from the lower portion of the cavity 13 into the cavity 13.
Meet. Into this casting, a portion of the molten metal of the weld surface 20 side, so Komu flow toward the heating chamber 25 through the communication grooves 26 ₁ to 26 ₃ without stagnation therein, welding surface 2 Sintered body 8
0 side and the non-welded surface 23 side as well as both outer surfaces 2
The temperature is also increased rapidly and sufficiently by heating from the 1, 22 side,
Further, it is possible to keep the high temperature state for a predetermined time. Thereby, even if the increase in the volume of the heating chamber 25 is suppressed, the welding rate of the sintered body 8 can be improved.

Also, the three communication grooves 26₁~ 26_ThreeStaggered
When arranged in a shape, as shown in FIG.
Two communication grooves 26 that are adjacent to each other_Two, 26_ThreeSintered body
8 heating area R with respect to welding surface 20_Two, R_ThreeSome
And the two heating zones R_Two, R_ThreeAnd others
Communication groove 26 on the outer surface 22 side₁Heating area R ₁
Can be partially overlapped with
Less communication groove 26₁~ 26_ThreeThe sintered body 8
It can be heated sufficiently.

Welding area a on welding surface 20 of sintered body 8
, When the entire welding surface 20 is not welded is substantially similarly to emerge and the heating region R ₁ to R _3. In this case, when the overlapping portion is generated as described above, the welding surface 2
0, the unwelded area b is present independently to avoid the occurrence of a continuous unwelded area on the welding surface 20 over the entire length of the cam shaft 1 in the axial direction c, that is, from one outer surface 21 to the other outer surface 22. can do. This is effective in avoiding a problem such as a decrease in the welding strength of the sintered body 8 in the camshaft rotation direction due to the generation of the continuous unwelded area as described above.

After the casting, the shell mold 9 is broken, and FIG.
A camshaft material 29 shown in FIGS. Each heating chamber 25 and each communication groove 26 are provided in this camshaft material 29.
_1-26 scrap portion 30 which corresponds to ₃ are attached, also communicating groove corresponding portion 31 _{1-31 3} of the scrap portion 30
Notches 32 are formed by small ridge 28 _1, 28 ₂ in. Therefore, if the heating chamber corresponding portion 33 of each scrap portion 30 is hit with a hammer or the like, the scrap portion 30 is broken by each notch 32 and the sintered body 8 is positioned at the barrier layer 24.
More off.

The camshaft material 29 includes a barrier layer 24
, And a scraping operation such as removal of a scrap portion corresponding to the gate 14 are performed, and thereafter, predetermined machining is performed.

Table 1 shows the composition and hardness H _R C of the alloy cast iron constituting the camshaft main body 6 and the particle-dispersed alloy cast iron constituting each sintered body 8.

[0020]

[Table 1]

A camshaft material 29 having the composition shown in Table 1
, The weight of the base circle portion corresponding portion 34 is₁When
And the weight of the sintered body 8 is W_TwoAnd W_Two= 0.
2W ₁Assuming that the relationship
Weight W of corresponding part 34₁And the weight of the heating chamber corresponding part 33
Quantity W_ThreeRatio W_Three/ W₁And the welding rate R of the sintered body 8
As a result, the results shown in Table 2 were obtained. In the table, the examples are
This corresponds to the well mold 9 and the comparative example is the lower one as the communication groove
26₁This corresponds to a shell mold having only

The casting temperature of the alloy cast iron composition was set at 1440 ° C., and the thickness of the barrier layer 24 was set at about 2 mm. Further, the welding rate R was determined as R = (B / A) × 100 (%), where A is the area of the welding surface 20 of the sintered body 8 and B is the area of the welding area a.

[0023]

[Table 2]

As is clear from Table 2, when the ratio W ₃ / W ₁ is set to W ₃ / W ₁ ≧ 2.0, the sintered body 8 is made to have a base circular portion in both the example and the comparative example. It can be completely welded to the corresponding part 34. On the other hand, when the welding rate R is R <100%, the welding rate in the example is higher than that in the comparative example. This is due to differences in the arrangement of the communication groove 26 _{1-26 3.}

FIG. 13 shows another example of the camshaft 1 in which the remaining portions 35 of the communication groove corresponding portions 31 _{1 to} 31 ₃ of the scrap portion 30 are left so as to extend between the base circular portion 5 and the sintered body 8. It was made. In this case, the portion of the barrier layer 24 facing each of the remaining portions 35 in the sintered body 8 has been removed in advance. These residual portions 35 increase the welding strength of the sintered body 8 to the base circle portion 5.

[0026]

According to the first aspect of the present invention, with the above-described structure, a cast-in insert capable of suppressing an increase in the volume of the heating chamber and improving the welding rate of the insert-receiving member. A casting mold can be provided.

According to the second aspect of the present invention, it is possible to provide a cast-in mold capable of minimizing the number of communication grooves and improving the welding rate of the cast-receiving member.

[Brief description of the drawings]

FIG. 1 is a front view of a camshaft.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a vertical sectional front view of a shell mold.

FIG. 4 is an enlarged view of a main part of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 4;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 4;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 4;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 4;

FIG. 9 is a perspective view of a sintered body having a barrier layer.

FIG. 10 is an explanatory diagram showing a relationship between a welding surface and a heating region by each communication groove.

FIG. 11 is a front view of a main part of a camshaft material.

FIG. 12 is a sectional view taken along line 12-12 of FIG. 11;

FIG. 13 is a cross-sectional view showing another example of the camshaft.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Camshaft (structural member) 6 ... Camshaft main body (member main body) 8 ... Sintered body (cast toy member) 9 ... Shell mold (mold) 13 ... Camshaft molding Cavities (cavities for forming structural members) 16 ... Nose portion-corresponding areas (areas for placing cast-insulated members) 20 ... Welding surfaces 21 and 22 ... Outer surfaces 23 ... Non-welding surfaces 24 ... Barrier layers 25 ... ... Heating chambers 26 _{1 to} 26 ₃ ... Communication grooves 28 ₁ and 28 ₂ ... Small convex ridges with a mountain cross section 29... Cam shaft material 30... Scrap portions 31 _{1 to} 31 _3. 32: Notch due to small ridges 33: A portion corresponding to the heating chamber of the scrap portion 34: A portion corresponding to the base circular portion 35: A remaining portion of the scrap portion corresponding to each communication groove.

Claims (2)

[Claims] 1. A member body (6) and the member body (6)
In order to cast a structural member (1) consisting of a to-be-stuffed member (8) welded to the surface, the to-be-stuffed member installation area (1)
6) a cavity (13) for molding a structural member, and a heating chamber (25) facing a non-welding surface (23) on the opposite side of the welding surface (20) of the to-be-molded member (8).
And a communication groove for supplying molten metal from the cavity (13) to the heating chamber (25).
A plurality of the communicating groove (26 ₁ to 26 _3), which communicating groove (26 ₁ to 26 _3), said during the welding surface of the insert casting member (8) (20) and the non-weld surface (23) A cast-in mold which is disposed so as to face both outer surfaces (21, 22) opposed to each other. And wherein said communication groove facing one of said outer surface (22) (26 _1), does not face to each other and the communication groove facing the other of said outer surface (21) (26 _2, 26 ₃₎ 2. The casting mold according to claim 1, wherein the casting molds are arranged so as to be shifted from each other.