JP2011218419A - Molding die and method of replacing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die with a simple structure, whose die insert is easily removed from a reinforcing ring for its replacement as needed for the replacement and whose components not requiring replacement are reused and to provide a method of replacing the same.SOLUTION: The die 1 which is a molding die includes: the die insert 10 with a molded section 10a; the reinforcing ring 11 which holds the die insert 10 with predetermined fastening force; and an inner ring 12 which is positioned between the die insert 10 and the reinforcing ring 11. The inner ring 12 is composed of a material which melts or is soften at the temperature between the temperature of the section 10a of the die insert 10 and the heat softening temperature of the die insert 10 and the reinforcing ring 11. The reinforcing ring 11 provides flow paths 11a which flow thermal media with adjusted temperatures.

Description

  The present invention relates to a molding die used for, for example, cold forging and compacting of a green compact and a replacement method thereof. More specifically, the present invention relates to a die insert having a molding portion and a predetermined fastening by press-fitting the die insert. The present invention relates to a molding die having a reinforcing ring that is held by force and capable of exchanging at least one of a die insert and a reinforcing ring as required, and a method for exchanging parts of such a molding die. It is.

  In a mold to which a high molding pressure is applied, in order to prevent damage mainly due to tensile stress, generally, a compressive stress in the circumferential direction is applied to the die insert in advance by tightening the die insert with a reinforcing ring, It is known to relieve a circumferential tensile stress generated in a die insert (for example, Patent Document 1). When assembling the die insert into the reinforcing ring, the outer diameter of the die insert and the inner diameter of the reinforcing ring are set to have a predetermined tightening allowance. For example, the die insert is attached to the reinforcing ring using a press machine or the like. Press fit. In addition, when it is necessary to heat and maintain the molding part at a predetermined temperature during molding, for example, hot forging, a flow path for circulating a heat medium adjusted to a predetermined temperature is also provided in the reinforcing ring. ing.

  Patent Document 1 discloses a structure in which an auxiliary reinforcing ring 3 made of a material having a larger longitudinal elastic modulus is disposed between a die insert 1 and a reinforcing ring 2 in a compression mold. In Patent Document 1, the purpose is to prevent the lateral cracking of the mold, and the deformation at the time of use of the die insert 1 that causes the lateral cracking is received by the auxiliary reinforcing ring 3 that is more difficult to deform. It describes what to do. Patent Document 1 describes that the die insert 1 and the auxiliary reinforcing ring 3 are coupled by interference fit, mechanical coupling, or welding.

Japanese Utility Model Publication No. 63-34543

  However, in the above-described conventional technique, when the die insert is press-fitted into the reinforcing ring and used for molding, the surface pressure between the two may increase, thereby fixing the die insert. In such a molding die, the higher the molding pressure, the higher the surface pressure between the two and the more likely that sticking occurs.

  On the other hand, if the die insert is worn out or one of the die insert and the reinforcing ring is broken due to pressure during molding, the die insert is removed from the reinforcing ring using, for example, a press machine. Replace necessary parts. When replacing the parts in this way, if the outer peripheral surface of the die insert and the inner peripheral surface of the reinforcing ring are fixed as described above, a relatively large load is applied to the press machine for extracting the die insert from the reinforcing ring. Necessary. A press machine capable of generating such a large load is generally large-scale and has a problem of cost. Even if the die insert can be extracted from the reinforcing ring, so-called galling occurs on both the outer peripheral surface of the die insert and the inner peripheral surface of the reinforcing ring in order to extract it from the fixed state, and no replacement is necessary. Even parts are required to be polished to correct galling, and it takes time and labor to replace them. In addition, the parts cannot be reused and are expensive.

  Further, as described above, galling is generated between the inner peripheral surface of the reinforcing ring and the outer peripheral surface of the die insert, and after repairing such as galling, the reinforcing ring is replaced with a new part. When the die insert is press-fit into the die insert, it becomes difficult to guarantee the adhesion between the inner peripheral surface of the reinforcing ring and the outer peripheral surface of the die insert. In the case where the reinforcing ring is provided with a flow path through which the heat medium adjusted to the predetermined temperature is passed in order to heat or cool the molded portion to the predetermined temperature during molding, the inner peripheral surface of the reinforcing ring and the die If the adhesion with the outer peripheral surface of the insert is poor, the heat held by the heat medium flowing through the flow path cannot be conducted well from the reinforcing ring to the molded part of the die insert, and the molded part is kept at a predetermined temperature. There was also a problem that it could not be heated or cooled.

  The present invention has been made in view of the above-mentioned problems. When it is necessary to replace a part with a simple configuration, the die insert is easily removed from the reinforcing ring and replaced. It is an object of the present invention to provide a molding die that can be used and an exchange method thereof.

In order to achieve the above object, the invention according to the first aspect of the present invention provides a molding die including a die insert having a molding portion and a reinforcing ring that is press-fitted and held with a predetermined fastening force. An inner ring disposed between the die insert and the reinforcing ring, which is made of a material that melts or softens at a temperature equal to or higher than the temperature of the molding portion and lower than the heat softening temperature of the die insert and the reinforcing ring. It is characterized by having.
In order to achieve the above object, the invention according to the molding die replacement method of claim 2 includes a die insert having a molding portion, and a reinforcing ring that is press-fitted and held with a predetermined fastening force. A mold for exchanging at least one of the die inserts from the reinforcing ring, and a melting point that melts at a temperature equal to or higher than the temperature of the molding part and equal to or lower than the heat softening temperature of the die insert and the reinforcing ring. An inner ring made of a material is disposed between the die insert and the reinforcing ring to pre-configure a mold for molding, and when replacing at least one of the die insert and the reinforcing ring, the inner ring is melted. Alternatively, the die insert is extracted from the reinforcing ring by heating to a softening temperature.

According to the first aspect of the present invention, the inner ring is provided between the die insert and the reinforcing ring, and the inner ring is heat-softened between the die insert and the reinforcing ring at a temperature equal to or higher than the temperature of the molded portion of the die insert. By being made of a material that melts or softens below the temperature, the compressive stress in the circumferential direction is applied to the die insert through the inner ring by the reinforcing ring while the inner ring is disposed between the die insert and the reinforcing ring. Since it is given in advance, the circumferential tensile stress generated in the die insert can be relaxed. If it is necessary to replace at least one of the die insert and the reinforcing ring, the die insert can be easily pulled out from the reinforcing ring easily with a small load by heating to a temperature at which the inner ring melts or softens. Therefore, it is possible to provide a molding die capable of reliably exchanging necessary parts and reliably reusing parts which do not need to be replaced.
According to the second aspect of the present invention, the molding die has the inner ring disposed between the die insert and the reinforcing ring, so that the compressive stress in the circumferential direction is applied to the die insert via the inner ring. Since it is given beforehand, the circumferential tensile stress generated in the die insert is relieved. When it is necessary to replace at least one of the die insert and the reinforcing ring, the die insert is removed from the reinforcing ring by heating to a temperature at which the inner ring melts or softens. At this time, since the inner ring is heated and melted or softened, the die insert that is fixed as in the conventional technique is easily removed without forcibly removing the die insert from the reinforcing ring and generating galling. The die insert can be pulled out from the reinforcing ring without difficulty by the load. Therefore, it is possible to provide a method for exchanging a molding die that can surely replace necessary parts and can reliably reuse parts that do not need to be replaced.

(Aspect of the Invention)
In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following items, item (1) corresponds to claim 1, and item (4) corresponds to claim 2.

(1) A molding die including a die insert having a molding portion and a reinforcing ring into which the die insert is press-fitted and held with a predetermined fastening force,
It is made of a material that melts or softens at a temperature equal to or higher than the temperature of the molding part and lower than the heat softening temperature of the die insert and the reinforcing ring, and includes an inner ring disposed between the die insert and the reinforcing ring. Mold for molding.

  In the invention of (1), since the compressive stress in the circumferential direction is preliminarily applied to the die insert by the reinforcing ring in a state where the inner ring is disposed between the die insert and the reinforcing ring, the die insert It is possible to relieve the tensile stress generated in the circumferential direction. When it is necessary to exchange at least one of the die insert and the reinforcing ring, the die insert is heated to a temperature at which the inner ring melts or softens. This makes it easy to remove the die insert from the reinforcement ring easily and with a small load without forcibly removing the die insert from the reinforcement ring as in the conventional technology and causing galling. In addition, parts that do not require replacement can be reliably reused.

  (2) The molding die according to (1), wherein the reinforcing ring is provided with a flow path for circulating a heat medium adjusted to a predetermined temperature.

  In the invention of the item (2), in the invention described in the item (1), when replacing the parts, the inner ring is heated to be melted or softened so that the die insert cannot be forced from the reinforcing ring without generating galling. Since the inner ring is disposed between the die insert and the reinforcing ring, the compressive stress in the circumferential direction is preliminarily applied to the die insert through the inner ring by the reinforcing ring. Since the inner ring and the reinforcing ring and the inner ring are in close contact with each other, at the time of molding, the heat of the heat medium flowing through the flow path provided in the reinforcing ring is surely formed. Can be precisely adjusted to heat or cool the molded part to the desired temperature.

  (3) The mold for molding according to (1) or (2), wherein the melting point of the inner ring is 150 to 500 ° C.

  In the invention of the item (3), when the inner ring is made of a material having a melting point of 150 to 500 ° C. in the invention described in the item (1) or (2), the parts need to be replaced. In addition, heating the inner ring to 150 to 500 ° C. ensures that the inner ring is melted or softened. Therefore, the die insert that is fixed as in the prior art is forcibly extracted from the reinforcing ring to generate galling. Therefore, the die insert can be easily pulled out from the reinforcing ring without difficulty with a small load, and necessary parts can be reliably replaced, and parts that do not need to be replaced can be reliably reused.

(4) A molding die including a die insert having a molding portion and a reinforcing ring that is press-fitted and held with a predetermined fastening force, and at least one of the die inserts is extracted from the reinforcing ring and replaced. An exchange method,
An inner ring made of a melting point material that melts or softens at a temperature equal to or higher than the temperature of the molding portion and lower than the heat softening temperature of the die insert and the reinforcing ring is disposed between the die insert and the reinforcing ring. Pre-configured,
When exchanging at least one of the die insert and the reinforcing ring, the die insert is removed from the reinforcing ring by heating to a temperature at which the inner ring melts or softens.

  In the invention of the item (4), the molding die is preliminarily applied to the die insert by means of the reinforcing ring in a state where the inner ring is disposed between the die insert and the reinforcing ring. The circumferential tensile stress generated in the die insert is relaxed. When it is necessary to replace at least one of the die insert and the reinforcing ring, the die insert is removed from the reinforcing ring by heating to a temperature at which the inner ring melts or softens. At this time, since the inner ring is in a molten or softened state, the die insert that is fixed as in the prior art is easily pulled out from the reinforcing ring without causing galling, and easily with less load. Since the die insert can be extracted from the reinforcing ring, necessary parts can be reliably replaced, and parts that do not need replacement can be reliably reused.

  (5) The method for replacing a molding die according to (4), wherein the inner ring is made of a material having a melting point of 150 to 500 ° C.

  In the invention of the item (5), in the invention described in the item (4), the inner ring is made of a material having a melting point of 150 to 500 ° C., so that the inner ring When heated to 500 ° C, the inner ring becomes melted or softened, so that it is impossible to easily remove the fixed die insert from the reinforcing ring as in the prior art and generate galling with less load. Without removing the die insert from the reinforcing ring, the necessary parts can be reliably replaced, and the parts that do not need to be replaced can be reliably reused.

It is sectional drawing of the metal mold | die for shaping | molding of this invention. It is a perspective view of the die | dye shown in FIG. FIG. 3 is a cross-sectional view for explaining a mold for integrally molding an inner ring with a reinforcing ring in the molding die of the present invention. FIG. 4 is a cross-sectional view illustrating a state in which a die insert is press-fitted into a reinforcing ring in which an inner ring is integrally formed with the mold illustrated in FIG. 3. FIG. 3 is a cross-sectional view for explaining a mold for molding an inner ring integrally with a die insert in the molding die of the present invention. It is sectional drawing shown in order to demonstrate the state which press-fits the die insert by which the inner ring was integrally shape | molded by the casting_mold | template shown in FIG. 5 with respect to a reinforcement ring.

First, an embodiment of the molding die according to the present invention is based on FIG. 1 and FIG. 2 in a case where a sintering material such as a metal powder is molded into a compact of a predetermined shape. This will be described in detail. In the drawings, the same reference numerals denote the same or corresponding parts.
The molding die of the present invention is generally disposed between a die insert 10 having a molding portion 10a, a reinforcing ring 11 that holds the die insert 10 with a predetermined fastening force, and the die insert 10 and the reinforcing ring 11. The inner ring 12 is made of a material that melts or softens at a temperature between the temperature of the molding portion 10a of the die insert 10 and the thermal softening temperature of the die insert 10 and the reinforcing ring 11. Has been.
The reinforcing ring 11 is provided with a flow path 11a for circulating a heat medium adjusted to a predetermined temperature.

  The molding die in this embodiment is constituted by a die 1 and punches 2 and 3 that are inserted into a molding portion 10a of the die 1, and the die 1 is composed of a die insert 10, an inner ring 12, and The reinforcing ring 11 is used.

  The die insert 10 is formed in a substantially columnar shape, and a molded portion 10a having a predetermined cross-sectional shape is formed at substantially the center thereof so as to penetrate in the axial direction (vertical direction in the figure). The punches 2 and 3 are formed in a cross-sectional shape corresponding to the cross-sectional shape of the forming part 10a of the die insert 10, and the lower punch 2 that is inserted into the forming part 10a from below and the forming part 10a. The upper punch 3 is inserted and extracted from above. The die 1 and the lower punch 2 are supported so as to be able to move up and down relatively, and the upper punch 3 is supported by, for example, a ram of a press machine.

  The reinforcing ring 11 is formed in a substantially cylindrical shape having an inner diameter larger than the outer diameter of the die insert 10, and a flange projecting radially outward is integrally formed below the reinforcing ring 11. A plurality of flow paths 11a for circulating the heat medium adjusted at a predetermined temperature (including cases where the temperature is higher (normally heating (heating) and lower than normal temperature (cooling)) are formed so as to penetrate the flange.

  The inner ring 12 is made of a material made of a metal such as tin or bismuth and an alloy containing at least one of these metals. The inner ring 12 is preferably made of a material having a melting point of 150 to 500 ° C.

  In the case of the embodiment shown in FIG. 1, the die 1 is formed so that the outer peripheral surface of the die insert 10 and the inner peripheral surface of the reinforcing ring 11 increase in diameter from the upper side to the lower side in a similar manner. A predetermined gradient is formed with respect to one central axis C (see FIG. 1). Further, the inner ring 12 is formed so that the thickness thereof is substantially constant, and the inner peripheral surface and the outer peripheral surface correspond to the outer peripheral surface of the die insert 10 and the inner peripheral surface of the reinforcing ring 11, respectively. A predetermined gradient is formed with respect to the central axis C of the die 1.

  Here, a manufacturing method of the die 1 configured as described above will be described. In the die 1 of the present invention, the inner ring 12 is formed separately from the die insert 10 and the reinforcing ring 11, and the inner ring 12 and the reinforcing ring 11 are sequentially arranged concentrically from the upper side of the figure of the die insert 10 (that is, the die By inserting the outer peripheral surface of the insert 10 having a smaller diameter from the inner peripheral surface of the inner ring 12 and the inner peripheral surface of the reinforcing ring 11 having a larger diameter, and pressing the whole The die insert 10 can be assembled by being press-fitted into the reinforcing ring 11 via the inner ring 12. Further, as shown in FIG. 3, the first mold 4 and the second mold 5 that form the cavity 6 for forming the inner ring 12 in cooperation with the reinforcing ring 11 by closing the mold are configured. 12 may be formed integrally with the reinforcing ring 11, and the die 1 may be assembled by press-fitting the die insert 10 into the inner ring 12 formed integrally with the reinforcing ring 11, as shown in FIG. Furthermore, as shown in FIG. 5, the first mold 4 and the second mold 5 that form the cavity 6 for forming the inner ring 12 in cooperation with the die insert 10 by closing the mold are configured. The die 1 may be assembled by forming the ring 12 integrally with the die insert 10 and press-fitting the inner ring 12 formed integrally with the die insert 10 into the reinforcing ring 11 as shown in FIG.

Next, one embodiment of the molding die replacement method of the present invention will be described in more detail when applied to the molding die configured as described above.
The molding die replacement method of the present invention generally includes a die insert 10 having a molding portion 10a and a reinforcing ring 11 into which the die insert 10 is press-fitted and held with a predetermined fastening force. An inner ring that is extracted from the reinforcing ring 11 and replaces at least one of the members 10 and 11 and is made of a melting point material that melts at a temperature equal to or higher than the temperature of the molding portion 10a and lower than a heat softening temperature of the die insert 10 and the reinforcing ring 11. 12 is disposed between the die insert 10 and the reinforcing ring 11 to form a molding die in advance, and when replacing at least one of the die insert 10 and the reinforcing ring 11, the inner ring 12 is melted or softened. The die insert 10 is pulled out from the reinforcing ring 11 and heated to a new temperature. And those assembled by press-fitting the at least one 10, 11 and the other 11, 10 of the reinforcing ring 11.

  As described above, the molding die in this embodiment is configured such that the die 1 has the inner ring 12 interposed between the die insert 10 and the reinforcing ring 11. The inner ring 12 is made of a melting point material that melts or softens at a temperature equal to or higher than the temperature of the molding portion 10a of the die insert 10 and equal to or lower than the thermal softening temperature of the die insert 10 and the reinforcing ring 11 itself. In the die 1, the die insert 10 is press-fitted into the reinforcing ring 11 with a predetermined fastening force with the inner ring 12 interposed, so that the compressive stress in the circumferential direction is passed through the inner ring 12 and the die insert 10. Is given in advance.

  In this embodiment, as shown in FIG. 1, a predetermined amount of metal powder is inserted in a state where the lower punch 2 is inserted into the molding portion 10a of the die insert 10 and the upper punch 3 is extracted from the molding portion 10a. The molding material 10a is filled in the molding part 10a, the upper punch 3 is inserted into the molding part 10a of the die insert 10, and a relatively large pressure is applied to mold a green compact of a predetermined shape. At this time, the die insert 10 tends to expand radially outward due to a relatively large pressure applied to the sintering material between the lower punch 2 and the upper punch 3 in the molding portion 10a. Tensile stress is generated. However, since the die 1 is preliminarily applied with a compressive stress in the circumferential direction so that the die insert 10 is contracted radially inward with a predetermined fastening force through the inner ring 12 by the reinforcing ring 11, The tensile stress in the circumferential direction of the die insert 10 due to a large pressure is relieved.

  In this embodiment, when the green compact is molded, a heat medium whose molding part 10a is adjusted to a predetermined temperature is circulated through the flow path 11a. On the other hand, in a state in which the inner ring 12 is disposed between the die insert 10 and the reinforcing ring 11, a circumferential compressive stress is preliminarily applied to the die insert 10 via the inner ring 12 by the reinforcing ring 11 with a predetermined fastening force. In addition, since the inner ring 12 is formed integrally with the die insert 10 (see FIGS. 5 and 6) or the reinforcing ring 11 (see FIGS. 3 and 4), the die insert 10 and the inner ring 12 And the reinforcement ring 11 and the inner ring 12 will adhere | attach each reliably. Therefore, when the green compact is molded, the heat of the heat medium flowing through the flow path 11a provided in the reinforcing ring 11 is surely conducted to the molded portion 10a of the die insert 10, and the molded portion 10a is made to have a desired shape. It can be precisely adjusted to heat or cool to temperature.

  When the molding 10a of the die insert 10 is worn or damaged due to repeated molding or the like and needs to be replaced, the inner ring 12 is melted by placing the die 1 in a furnace or the like. Heat to softening temperature. As a result, the inner ring 12 interposed between the die insert 10 and the reinforcing ring 12 becomes flowable, so that the die insert that has been tightened by being press-fitted into the reinforcing ring 11 before being heated. 10 can be pulled out from the reinforcing ring 11 easily and easily with a small load, and the outer peripheral surface of the die insert 10 and the inner peripheral surface of the reinforcing ring 11 do not generate galling. Parts that are not present (for example, the reinforcing ring 11 when only the die insert 10 is replaced) can be used again as they are. The inner ring 12 can also be used repeatedly by being melted again and cast into the molds 4 and 5.

  The present invention includes a die having a molded part that penetrates and a punch that is inserted into the molded part, and is not limited to a molding die that is used for molding a sintered compact. The present invention can also be applied to a molding die used for, for example, hot forging, in which a cavity is formed in cooperation with another molding die that is opened and closed with respect to a die insert.

  1: Die, 2: Lower punch, 3: Upper punch, 10: Die insert, 10a: Molding part, 11: Reinforcement ring, 11a: Flow path, 12: Inner ring

Claims (2)

A molding die comprising a die insert having a molding portion and a reinforcing ring that is press-fitted and held with a predetermined fastening force,
It is made of a material that melts or softens at a temperature equal to or higher than the temperature of the molding part and lower than the heat softening temperature of the die insert and the reinforcing ring, and includes an inner ring disposed between the die insert and the reinforcing ring. Mold for molding. A molding die replacement method comprising: a die insert having a molding portion; and a reinforcing ring that is press-fitted and held with a predetermined fastening force, and at least one of the die insert is removed from the reinforcing ring and replaced. There,
An inner ring made of a melting point material that melts or softens at a temperature equal to or higher than the temperature of the molding portion and lower than the heat softening temperature of the die insert and the reinforcing ring is disposed between the die insert and the reinforcing ring. Pre-configured,
When exchanging at least one of the die insert and the reinforcing ring, the die insert is removed from the reinforcing ring by heating to a temperature at which the inner ring melts or softens.

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