JPH01306038A - Manufacture of metallic product having tubular part - Google Patents

Abstract

PURPOSE:To form a product having a tubular body in part of the configuration, homogeneous in quality and full in strength by storing the tubular body in a casting mold, pouring molten metal to obtain a casting of the tubular body and a binding member, then, executing the forging. CONSTITUTION:The tubular body 2 and a hollow part 10 to form a binding member to be integrated with the tubular body 2 are provided between a lower mold 11 for casting and an upper mold 12 therefor. A core plug 3 is fitted so that excessive molten metal is not poured into the tubular body 2. The molten metal is poured from a sprue 13 and solidified, a casting is taken out of a casting mold, the core plug 3 is removed and the casting of the binding member 1 is obtained through a deburring stage. This preliminary bound body 5 is forged so that a desired finished shape is obtained by setting the upper mold with the same shape as the lower mold 16 for forging on a casting machine. In this way, it is possible to mass-produce products having a small diameter tube and a thin-walled tube each on part of the configuration or products homogeneous in quality, full in strength and integral in appearance each.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method most suitable for manufacturing a metal product integrally holding a tube body, particularly a thin-walled tube body.

Prior Art Conventionally, when manufacturing a metal product that has a tubular part as part of the product structure, a pipe and a connecting member to be combined with the pipe and integrated are prepared separately in advance, and the connecting member side is Pressing the pipe into the protrusion or hole provided,
Alternatively, the pipe and its connecting member are integrated into a product by welding their joints or by fixing them with a fixing device such as a bottle or screw.

However, with these methods, especially when the pipe that forms the tubular part of the product is thin, the pipe may be damaged or deformed at the joint, making it difficult to integrate. In addition to being time consuming to process, it is difficult to obtain uniform strength at the joint, and the appearance is unsightly.

Structure of the Invention The present invention has been made in response to the above-mentioned circumstances, and the gist thereof is that when manufacturing a metal product that has a tube as a part of the structure of the product to be manufactured, The connecting member and the pipe body to be combined are prepared in advance as separate members, and the connecting member is made of 8! Either by fitting the tube body and combining the two by performing machining processing, or when manufacturing the connecting member by casting, the tube body is housed in the casting mold, and the molten metal is poured into the casting mold. By pouring, the joint parts of the two are fitted and combined, and the pipe body and its joint member are pre-bonded, and this preliminary joint body is subjected to a forging process, whereby the pipe body and its joint member are bonded together. The fitting part is deformed and crimped to obtain a product in which both parts are integrated firmly and aesthetically.

Hereinafter, embodiments will be described in detail with reference to the drawings.

Figure 1 shows that when manufacturing a connecting member to be integrated with a tube body by casting, the tube body and the connecting member are pre-bonded using the casting process, and then subjected to a forging process for final forming. This shows the case when doing this.

In FIG. 1-7, in the lower mold 11 and upper mold 12 for casting,
In advance, a cylindrical hollow part matching the diameter of the tube body 2 that forms a part of the target product and a hollow part 10 for molding the coupling member to be integrated into the tube body 2 are formed in a state that communicates with this hollow part. Form it. The tube body 2 is housed in a predetermined position in such a casting mold 11, 12. At this time, the inner plug 3 is fitted into the pipe body 2 so that the molten metal does not flow into the pipe body 2 more than necessary. The inner stopper 3 has a fitting part 3a into the pipe body 2 and a protrusion part 3 having the same diameter as the pipe body 2.
c, but the tip 3b of the fitting part 3a is placed in a position slightly retracted into the tube body 2 from the end 2a of the tube body 2 on the hollow part (10) side, so that the molten metal does not flow into the tube. It is desirable that a portion of the molten metal flow into the body 2 so that the vicinity of the end of the tube body 2 is sandwiched between the molten metal from both sides. This means that the pipe
This is particularly important when section 2 is a thin-walled tube.

Since the inner stopper 3 is used to define the limit range for the molten metal to reach the inside of the tube, it does not necessarily have to be a stepped frame with different diameters as shown in the figure. An MII structure that can prevent the movement of objects is sufficient. 13 is a sprue;
14 is a hot water path.

In this state, molten metal flows from the sprue 14,
For example, after pouring a molten aluminum alloy and solidifying it, the molded product is taken out of the mold, the inner plug 3 is pulled out, a deburring process is performed, and the tube body 2 is fitted and held as shown in Figure 1-A. A casting of the joining member 1 is obtained.

The pre-bonded body 5 of the tubular body 2 and the coupling member 1 thus obtained is combined with a lower die 16 for forging manufactured according to the dimensions of the target product, and an upper die of the same shape as the lower die (Fig. (not shown) are attached to a forging machine, and are forged until the desired finished shape is obtained. In FIG. 11-C, the abutting portion 17 of the forging die to the tubular body 2 is manufactured to be equal to the diameter of the tubular body 2, and the tubular body 2 is not subjected to pressing force by the forging die. In the process of such forging, the metal bubbles in the radial and axial directions of the connecting member 1, and the metal structure is refined and homogenized, and the metal structure is refined and homogenized. At the same time that the joint surfaces of the tube body and the coupling member are in close contact with each other, the pressure applied to the coupling member 1 is also applied to the tube body through the metal structure at the fitting portion of the tube body and the coupling member. The metal N weave itself changes and its shape deforms (2b), and therefore, at the bonding boundary between the two, the two metals intertwine in a complicated manner and are pressed together, achieving a strong integration. This crimping and integration of the tube body and its connecting member by forging is more effective if hot forging is used as the forging process.

Furthermore, by providing a plurality of holes 2c or recesses near the end of the tube as shown in FIG. 2, or by adding deformation as shown in FIG. The metal wraps around the deformed parts during forging, improving ff1l.

Furthermore, when manufacturing a product in which coupling members are integrally coupled to both sides of the tube body 2, as shown in Fig. f51,
Since a type of inner stopper that can be pulled out and removed is not used, in this case, an inner stopper that can be attached to the tube body 2 and fixed in that position is used. As such, for example, a truncated conical inner plug 7.7 as shown in FIG.
The largest diameter portion 7a is fixed by pressing against the inner circumferential surface of the tube, with the large diameter side facing toward the inside of the tube, and at a position slightly retracted from the end of the tube. The molten metal enters the tube from both sides of the tube body 2 and flows along the tapered surface 7b of the inner stopper 7 until it reaches its maximum diameter. 1S
After reaching around 7a, it is cooled and solidified to hold and fix the inner stopper 7. Such an inner stopper 7 can also be used in place of the inner stopper 3 in the embodiment shown in FIG.

The shape of the inner plug of the type that is installed inside the tube and integrated with the target product is not necessarily limited to one having a Taber surface, but may have a shape such as the inner plug 24 shown in Fig. S5-C. Any suitable material, such as one having a small diameter portion nearby, can be adopted.

In FIG. 5, a coupling member 21 is made in advance by machining such as cutting, casting, or forging, and a tube body 21 is attached to the coupling member 21.
This figure shows an example method of preliminarily bonding two parts and then subjecting the preliminarily bonded body to a forging process. In this case, in order to fit and pre-bond the tube body 22 to the coupling member 21 which has been manufactured by an optimal manufacturing method according to its shape, first, the coupling member 21 must be subjected to any necessary drilling or other processing. A fitting hole 23 is formed by processing. To this, pipe body 2
2 and pre-bond.

Forging this pre-bonded body 20 using a forging die as shown in FIG.
In order for the pressurizing force during casting to be applied to the fitting portion between the tube body 22 and the coupling member 21, and for the two to be effectively crimped, the material of the coupling member must be The core 24 is inserted into the tube 22 over the overlapping region of the tube and the coupling member so that the pressurizing force applied through the metal is not damped by the radial deformation of the tube 22. It is desirable to insert it. This is particularly important when the tube body 22 is thin. The center core may be in the shape of a round bar, but it should be shaped so that a slight gap remains between the inner peripheral surface of the tube body 22 and the center core, as shown in the center small diameter portion 24a shown in FIG. 5-C. Once decided, during forging, the plastic deformation of the tube and the ff of the connecting member can be controlled.
As a result, the crimping effect between the tubular body and the connecting member is large, and the core is fixed in its position with sufficient strength.

Of course, the core and the inner stopper may be made of the same material as the coupling member and the tube, or may be made of a different material.

Effects According to the method according to the present invention, in the manufacture of parts having a tube as a part of the structure, the two can be integrated with sufficient strength, and the appearance is similar to that of screws. Unlike welding, unnatural unevenness does not occur on the product.

In particular, when the pipe body has a small diameter or is thin-walled, conventional methods such as press-fitting, welding, screwing, etc.
However, according to the method of the present application, the pipe body may be deformed, the strength of the joint between the two members may not be maintained, and the joint may break or deform, making processing extremely difficult and expensive. ,
It is possible to inexpensively mass-produce a product having a small-diameter pipe or a thin-walled pipe as a part of the structure, which is homogeneous, has sufficient strength, and has a sense of unity in appearance.

[Brief explanation of the drawing]

FIGS. 1A to 1E are explanatory diagrams showing steps of a method according to an embodiment of the present invention. FIGS. 2 and 3 are explanatory diagrams showing examples of preliminary processing of a tube body used in the method of the present application, respectively. FIG. 4 is an explanatory diagram showing the main part of another embodiment of the method according to the present invention. tjIJ5 Figures A to C are explanatory diagrams showing essential parts of still another embodiment method of the present invention. Patent applicant Matsuo Forge Co., Ltd. Figure 1 5/' 72b1 (/

Claims (2)

[Claims] (1) When manufacturing a metal product having a tube as part of its structure, the tube is stored in advance in a casting mold for making a connecting member to be integrated with the tube, and the tube is placed in the casting mold in advance. After pouring molten metal into a mold to obtain a casting of the coupling member that fits and holds the tube, the casting is subjected to a forging process so that the tube and the coupling member are crimped and integrated. A method for manufacturing a metal product having a tubular part. (2) When manufacturing a metal product that has a tube as part of its structure, preliminary processing is performed on the coupling member to be integrated with the tube to form a fitting part with the tube, and 1. A method of manufacturing a metal product having a tubular part, characterized in that the tubular body and the coupling member are crimped and integrated by performing a forging process after fitting with the coupling member.