JP5146341B2 - Mold structure for insert molding and molding method - Google Patents

Description

  The present invention relates to a mold structure and a molding method for insert molding a part made of a shaft material and a powder metallurgy material.

  Conventionally, diffusion bonding parts such as those disclosed in Patent Document 1 are manufactured by incorporating two different materials A and C made of a powder metallurgy material C obtained by pressing a shaft material A and a raw material powder B in separate processes. A + C is made through an assembly process consisting of machines and manpower, and sent to a sintering process in which diffusion bonding is performed. This is aimed at strong bonding of the diffusion bonding itself, but reduction in the assembling process and high accuracy cannot be realized. That is, in the case of the prior art, an appropriate clearance is required for the portion to be incorporated, and high accuracy of the perpendicularity and coaxiality of the two members cannot be expected. FIG. 1 is an explanatory view incorporating a shaft material A and a powder metallurgy material C according to the prior art, and FIG.

JP 2005-133618 A

  In view of the wide demand for diffusion bonding with high strength, high accuracy, and labor saving, the present invention realizes high strength of the joint by insert molding at the time of raw material powder compression molding, It achieves higher accuracy, labor saving in the assembly process, and subsequent reduction of processing man-hours.

  The invention of claim 1 is a mold structure for insert-molding a part (1) comprising a shaft material (A) and a powder metallurgy material (C), the mold structure comprising a die (10) and the die (10) An upper punch (1) and a lower punch (2) inserted into the upper punch (1) so as to move up and down, a shaft presser (4) inserted into the upper punch (1) so as to move up and down, and the lower punch A core rod (3) inserted into the punch (2) so as to be movable up and down, and an upper surface of the core rod is provided with a set hole (2) for holding a part of the shaft material; The upper punch (1) and the lower punch (2) with the presser (4) and the lower punch (2) holding the shaft material (A) set in the setting hole (2) from above and below. The raw material powder (B) filled in the die between Shift material (A) is a powder metallurgy material component consisting of (C) (1) is a mold structure for insert molding.

  As a result, the structural strength of the joint portion is improved and the dimensional accuracy such as the perpendicularity of the joint portion is improved, thereby realizing labor saving in the assembling process and subsequent reduction in the number of processing steps.

The invention of claim 2 is a method of insert-molding a part (1) comprising a shaft material (A) and a powder metallurgy material (C), and is inserted into the die (10) and the die (10). An upper punch (6) and a lower punch (5), a shaft presser (4) inserted into the upper punch (6), and a core rod (3) inserted into the lower punch (5) are provided. In the mold structure,
The step of setting a part of the shaft material (A) in the set hole (2) of the core rod (3), and the shaft material (A) set by the shaft presser (4) and the core rod (3) And moving one or both of the upper punch (6) and the lower punch (5) to move the upper punch (6) and the lower punch (5). It is an insert molding method consisting of a step of squeezing the raw material powder (B) filled in the die. Thereby, the same effect as that of the invention of claim 1 can be realized.

In the invention of claim 3 , the joint surface between the shaft material (A) and the powder metallurgy material (C) is composed of a plurality of uneven portions .
As a result, the shape of the joint portion to be incorporated in the prior art had to be a straight line, but in the present invention, it can be an uneven surface, and the joining area is dramatically increased. High strength diffusion bonding that cannot be obtained by bonding can be realized. That is, in the part manufactured using the insert processing of the invention of claim 2, for example, when there is a mountain groove or the like in the head portion A ″ of the shaft material, B can enter the gap, and high strength diffusion bonding is performed. Can be realized.

It is explanatory drawing before incorporating the shaft material A and the powder metallurgy material C of a prior art. It is the schematic which shows an example of the components which consist of the shaft material A and the powder metallurgy material C. It is the schematic which shows typically the metal mold | die structure of one Embodiment of this invention, and its operation | movement. (A)-(c) is the schematic which shows typically the action | operation of a time-sequential order. It is a figure which shows the shape of another embodiment of the shaft material A. FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. About each embodiment, the same code | symbol is attached | subjected to the part of the same structure, and the description is abbreviate | omitted. Similarly, with respect to the prior art, parts having the same configuration are denoted by the same reference numerals and description thereof is omitted.

  An example of a part made of the shaft material A and the powder metallurgy material C of the present invention is as shown in FIG. The shaft material A is a general melted material. Includes materials commonly used for bearings, such as SKH51, SKH11, SUJ2. Examples of the powder metallurgy include a powder material having several types of additives and inevitable elements with Fe as a main element and having an average particle diameter of 10 μ to 80 μ.

  As an example to which the present invention is applied, it can be used for an armature of a fuel injection valve (see, for example, JP-A-2008-151048). According to the present invention, in the case of a fuel injection valve, it greatly contributes to high pressure and low price. In addition, in the diffusion bonding member of the shaft material and the powder metallurgy material, if the diffusion bonding surface is parallel to the pressing direction of the molding press, it can be applied to any shape material, and is not limited to the shape of FIG. A wide range of applications other than the armature of the fuel injection valve can be considered.

FIG. 3 is a schematic view schematically showing a mold structure and its operation according to one embodiment of the present invention along a time series.
3, in this mold structure, an upper punch 6 and a lower punch 5 are inserted into a fixed die 10 so as to be vertically movable. Both the upper punch 6 and the lower punch 5 are movable. A shaft retainer 4 is inserted into the inside 7 of the upper punch 6 so as to be movable up and down, and can be pressurized by a spring or air pressure. The core rod 3 is inserted into the lower punch 5 so as to be movable up and down. B is a filled raw material powder.
One of the upper punch 6 and the lower punch 5 may be moved to squeeze the raw material powder B filled in the die 10 between the upper punch 6 and the lower punch 5. That is, the pressure molding is not limited to the case of applying to the double pressing method, but may be applied to the single pressing method.

A set hole 2 for holding a part of the shaft material A is provided on the upper surface of the core rod 3. In the present embodiment, the shaft portion A ′ of the shaft material A is used to fit into the set hole 2. What is necessary is just to provide the shape of a set hole so that it can be hold | maintained according to the shape of insert material.
FIG. 4 is a diagram illustrating the shape of another embodiment of the shaft material A. FIG.

Next, an operation using the mold structure of one embodiment of the present invention and a process for performing insert molding will be described.
First, the shaft material A is set in the set hole 2, and the raw material powder B is filled in the die between the upper punch 6 and the lower punch 5. The raw material powder B filled in the die between the upper punch 6 and the lower punch 5 in a state where the shaft material A set in the set hole 2 is sandwiched from above and below by the shaft presser 4 and the core rod 3. The parts 1) composed of the shaft material A and the powder metallurgy material C are insert-molded.

  This process will be described with reference to (a) to (c) of FIG. The center line α is a line indicating the vertical physical center of the head A ″ of the shaft material A. β is a line indicating the vertical physical center in the initial state between the upper punch 6 and the lower punch 5. In FIG. 3A, the shaft holder 4 and the core rod 3 are in a state where the shaft material A set in the set hole 2 is pressed from above and below. Next, as shown in FIG. 3B, the shaft retainer 4 starts to be pressurized by air pressure or the like, and descends so that the line α coincides with the line β. By applying a desired pressing pressure between the upper punch 6 and the lower punch 5 in this state, insert molding is realized as shown in FIG. In addition, an example of pressing conditions, such as a pressure, about squeezing is 650 Mpa-1200 MPa.

  Thereafter, the part 1 made of the shaft material A and the powder metallurgy material C is sintered at a temperature of 1000 ° C. to 1300 ° C. as an example, thereby completing a sintered part in which the powder metallurgy material C is diffusion bonded to the shaft material A. To do.

As another embodiment, the case where the shape of the shaft material A of FIG. 4 is used will be described.
In this case, the head A ″ of the shaft material A is formed with a large number of grooves having a rectangular wave cross section. In the prior art as shown in FIG. In the case of this embodiment, as described above, with the shaft presser 4 and the core rod 3, the shaft material A set in the set hole 2 is clamped from above and below, and between the upper punch 6 and the lower punch 5. The raw material powder B filled in the die is squeezed to insert-mold a component 1) composed of a shaft material A and a powder metallurgy material C. For this reason, the raw material powder B enters the groove and the molding is completed. Since a large number of grooves are formed in the head A ″ in this way, the bonding area is dramatically increased, so that high-strength diffusion bonding that cannot be obtained by conventional diffusion bonding can be realized.
In addition, it is not restricted to the head groove shape of the shaft material A of FIG. 4, A screw groove may be sufficient and generally it can also be made into arbitrary uneven | corrugated shape.

  In the mold structure of the above-described embodiment, the upper punch 6 and the lower punch 5 are inserted into the fixed die 10 so as to be movable up and down. However, as another embodiment, the upper punch 6 or the lower punch 5 is inserted. One of the punches 5 may be moved to squeeze the raw material powder B filled in the die 10 between the upper punch 6 and the lower punch 5. That is, the pressure molding is not limited to the case of applying to the double pressing method, but may be applied to the single pressing method. In the case of molding by the one-push method, positioning control is performed so that the α line is lower than the β line in FIG. 3B, and finally the state shown in FIG. Must be controlled.

A Shaft material B Raw material powder C Powder metallurgy material 3 Core rod 4 Shaft retainer 5 Lower punch 6 Upper punch 10 Die

Claims (3)

A mold structure for insert-molding a part (1) composed of a shaft material (A) and a powder metallurgical material (C). The mold structure is formed into a die (10) and a die (10), respectively. An upper punch (6) and a lower punch (5) inserted movably, a shaft presser (4) inserted in the upper punch (6) to move up and down, and an upper punch (5) in the lower punch (5) A core rod (3) movably inserted;
The upper surface of the core rod (3) is provided with a set hole (2) for holding a part of the shaft material, and the shaft holder (4) and the core rod (3) are set in the set hole (2). With the shaft material (A) pressed from above and below, the raw material powder (B) filled in the die between the upper punch (6) and the lower punch (5) is squeezed, A mold structure for insert-molding a part (1) composed of a shaft material (A) and a powder metallurgy material (C). A method of insert molding a part (1) comprising a shaft material (A) and a powder metallurgy material (C),
Die (10), upper punch (6) and lower punch (5) inserted into die (10), shaft presser (4) inserted into upper punch (6), and lower punch (5) In a mold structure comprising a core rod (3) inserted in
Setting a part of the shaft material (A) in the set hole (2) of the core rod (3);
The shaft presser (4) and the core rod (3) sandwich the set shaft material (A) and move it to a predetermined position;
Raw material powder filled in the die between the upper punch (6) and the lower punch (5) by moving one or both of the upper punch (6) and the lower punch (5) An insert molding method comprising the step of squeezing B). 2. The mold structure according to claim 1, wherein the shaft material (A) includes a plurality of concave and convex portions at a joint surface between the shaft material (A) and the powder metallurgy material (C). .

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