JP2010137284A - Isothermal forging method and isothermal forging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an isothermal forging method which can simply, easily and surely maintain a material temperature in a die to a prescribed level, can surely prevent a material from being overheated above the prescribed temperature by fairly holding a processing speed during forging, can process a high-strength, high-toughness and high-quality component at high speed by micronizing a crystal grain, can eliminate heat-treatment after processing to minimize post-processing work, and thus is excellent in mass productivity. <P>SOLUTION: The isothermal forging method includes the steps of: heating the die; measuring and monitoring a die temperature; controlling the heating temperature in the die heating step so as to converge and maintain the surface temperature of a die inside to the processing level of the metal material on the basis of the temperature measured in the die temperature-monitoring step; heating a solution-heat-treated metal material to a temperature of ≥100°C to its recrystallization temperature or below; and forging the heated metal material by charging in the die whose temperature is controlled to a processing level in the above heating temperature-controlling step. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a constant temperature forging molding method and a constant temperature forging molding apparatus that are capable of forming a high-quality, high-toughness, high-quality part by constant-temperature forging a metal such as an aluminum alloy.

Forging has been conventionally known as a means for improving the strength and quality of metals.
In the hot forging method that does not heat the mold, the material temperature drops rapidly during processing and the moldability deteriorates, so defects are likely to occur, shape flexibility is lacking, and post-processing such as cutting process is required, There was a problem that the mass productivity was lacking and the use was limited.
In addition, the constant temperature forging method can improve strength and quality, but it is not suitable for manufacturing mass-produced products and small parts because it is a method that uses a large press to slow down the processing speed. However, it is used only for the production of large-scale small parts such as aircraft bodies and legs, and has a problem that it cannot be applied to mass-produced products.
In particular, in parts manufacturing for automobiles, railway vehicles, aircraft, etc., in response to environmental problems such as fuel efficiency regulations and exhaust gas regulations in recent years, there is a need to reduce the weight of car bodies and aircraft, and some parts are made of aluminum alloys. However, in terms of strength and quality assurance, the transition to lightweight alloys has not progressed, and the establishment of a constant temperature forging technique capable of high speed processing and excellent mass productivity has been strongly desired.
In addition, for various metal parts such as electric power equipment and housing-related facilities, development of manufacturing technology capable of reducing weight and increasing strength has been desired in order to improve transportability, handling, and durability.
On the other hand, a method for producing a metal material has been proposed in which a metal such as an aluminum alloy is heated and pressed at a recrystallization temperature or lower to refine crystal grains and improve strength.
For example, (Patent Document 1) states that “a bulk aluminum material made of aluminum or an aluminum alloy is heated to a recrystallization temperature or lower, and the bulk aluminum material heated to a temperature lower than the recrystallization temperature is converted to an x-axis direction, a y-axis direction, and a z-axis direction. "A method for producing aluminum and aluminum alloy materials having ultrafine crystal grains, characterized in that crystal grains in the massive aluminum material are made ultrafine crystal grains by repeatedly forging in the axial direction." .
In addition, (Patent Document 2) states that “a plastic metal material is sandwiched between molds at a temperature lower than the recrystallization temperature, and a large repetitive load is instantaneously applied to the mold while intermittently transporting the metal material. A method for producing a fine-grain metal material, comprising a step of pressing and rolling. "
JP 2004-176134 A JP 2005-200725 A

However, the above conventional techniques have the following problems.
(1) In (Patent Document 1), forging is repeatedly performed from each of the x-axis, y-axis, and z-axis directions. The sample is rotated by 90 ° for each forging and reheated to 1.2 ks at 523K each time. Since it was necessary to carry out, it had the subject that a process was complicated, processing took time, and mass production was lacking.
In addition, in order to obtain a desired shape, it is necessary to perform various post-processing such as cutting and polishing, which has a problem of lack of resource saving.
Also, by performing reheating for each forging, the temperature of the sample repeatedly rises and falls, the heating temperature is likely to vary, the crystal grain is not uniform, the rigidity and toughness vary, and the yield is likely to decrease. However, it had the problem of lack of quality stability and mass productivity.
(2) (Patent Document 2) is a process in which a metal material is intermittently transported little by little while a large repetitive load is instantaneously applied by a mold and subjected to a reduction process. In subsequent rolling, it is necessary to adjust the thickness of the material, finish the surface condition, or process it into a cross-sectional shape suitable for the application, and the processing process is complicated, requiring time for processing, and mass productivity. It had the problem of lacking.
(3) (Patent Document 1) and (Patent Document 2) are both methods for producing a metal material for miniaturizing crystal grains by setting the heating temperature of the material to less than the recrystallization temperature. There has been no description or suggestion of a specific heating method, measurement and management method of the heating temperature, or a configuration or structure of an apparatus for realizing them.

  The present invention solves the above-described conventional problems, and can easily and reliably maintain the temperature of the material in the mold at a predetermined temperature, appropriately maintain the processing speed during forging, and the material is determined in a predetermined manner. It is possible to reliably prevent heating above the temperature, refine the crystal grains, and high-speed processing of high-quality parts with high strength, high toughness, and no heat treatment after processing is required. Providing a constant temperature forging molding method with excellent mass productivity that can minimize post-processing, excellent heat insulation with a simple structure, reducing heat dissipation from the mold, and improving the efficiency of mold heating Excellent, the material in the mold can be reliably maintained at a predetermined temperature, the moldability and processing uniformity are excellent, the pressing force can be reduced, the size can be reduced, and high speed processing is possible. High quality forged parts with excellent reliability and durability with little variation And to provide excellent isothermal forging molding apparatus for mass production which can be produced.

In order to solve the above problems, a constant temperature forging molding method and a constant temperature forging molding apparatus of the present invention have the following configuration.
The constant temperature forging molding method according to claim 1 of the present invention includes a mold heating step for heating the upper mold and the lower mold, and a mold for measuring and monitoring the temperature of the upper mold and / or the lower mold. Based on the temperature measured in the temperature monitoring step and the mold temperature monitoring step, the heating temperature in the mold heating step is adjusted so as to converge and maintain the surface temperature inside the mold to the processing temperature of the metal material. A heating temperature adjusting step, a material heating step of heating the solution-treated metal material at a temperature of 100 ° C. or more and below a recrystallization temperature of the metal material, and the heating temperature adjustment of the metal material heated in the material heating step. And a forging process in which the forging process is performed by placing the mold in a mold whose temperature is adjusted to the processing temperature in the process.
This configuration has the following effects.
(1) Measured in a mold heating process for heating the upper mold and the lower mold, a mold temperature monitoring process for measuring and monitoring the temperature of the upper mold and / or the lower mold, and a mold temperature monitoring process. By having a heating temperature adjustment process that adjusts the heating temperature in the mold heating process so that the surface temperature inside the mold converges and maintains the processing temperature of the metal material based on the temperature, the inside of the mold and the inside of the mold Since the temperature of the metal material can be maintained at a predetermined processing temperature, the manufacturing conditions in the subsequent forging process can be kept substantially constant, and forged parts with high quality and excellent uniformity with little variation. It can be manufactured and has excellent quality reliability and mass productivity.
(2) Since there is a forging process in which the metal material heated in advance in the material heating process is put into a mold whose temperature has been adjusted to the processing temperature in the heating temperature adjustment process and forged, the metal material will not cool down. The processing pressure can be reduced and high-speed processing can be performed, and the mass productivity is excellent. In addition, it can be efficiently molded under substantially constant conditions regardless of winter or summer, and is excellent in production efficiency and stability.
(3) The material heating process for heating the solution-treated metal material to 100 ° C or more and below the recrystallization temperature of the metal material, and the metal material heated in the material heating process is adjusted to the processing temperature in the heating temperature adjustment process. By having a forging molding process in which it is put into a mold and forging molded, crystal grain refinement and precipitation hardening, which were performed separately in conventional cold forging, can be performed simultaneously, and after the forging molding process In addition, high-strength, high-toughness and high-quality forged molded parts can be manufactured without performing heat treatment separately, and it can be molded into a shape close to the final shape of the product, so post-processing such as cutting Is not required, the number of processing steps can be significantly reduced, the material yield can be improved, and mass productivity and resource saving are excellent.

Here, examples of the metal material processed by this constant temperature forging method include aluminum, aluminum alloy, copper, copper alloy, magnesium alloy, and iron-based alloy.
In the mold temperature monitoring step, the temperature of the mold can be measured and monitored at an arbitrary position set by the upper mold and / or the lower mold, and the temperature at the set measurement position and the inside of the mold can be measured. Setting the heating temperature in the mold heating process so that the internal (inner surface) temperature of the mold becomes the predetermined processing temperature by obtaining the relationship with the surface temperature (internal mold surface temperature) in advance. Can do. Therefore, the measurement position and number of temperatures can be selected as appropriate according to the mold shape and heating temperature. The mold temperature monitoring process does not necessarily directly measure the internal (inner surface) temperature of the mold. Therefore, the temperature of the mold can be measured easily and reliably by using a thermocouple or the like inside the mold (outer surface) or inside the insertion hole formed from the outer surface of the mold.

  The pressing force in the forging process can be selected as appropriate according to the shape, dimensions, etc. of the parts to be manufactured, but the pressing force can be kept lower than usual by heating the mold. The processing speed can be increased. As a result, the burden on the mold can be reduced, and the life of the mold can be extended.

The temperature of the metal material in the forging process is 100 ° C. or more, preferably 120 ° C. or more, more preferably 150 ° C. or more, and preferably less than the recrystallization temperature of the metal material. As the temperature of the metal material in the forging process becomes lower than 150 ° C., the moldability tends to decrease, and as the recrystallization temperature of the metal material becomes higher, the grain size of the crystal grains increases. , Strength and toughness tend to decrease. Also, if the temperature of the metal material in the forging process becomes lower than 120 ° C or 100 ° C, depending on the type of metal material and the size of the product, the physical properties will deteriorate significantly, and complex shapes will be molded. Tend to be difficult.
Although the recrystallization temperature varies depending on the type of metal material and its composition, for example, in the case of an aluminum alloy, it is about 250 ° C. to 300 ° C.

Invention of Claim 2 is the constant temperature forging molding method of Claim 1, Comprising: The process which adjusts the process speed in the said forge molding process based on the said temperature measured by the said metal mold temperature monitoring process It has the structure provided with the speed adjustment process.
With this configuration, in addition to the operation of the first aspect, the following operation is provided.
(1) Since there is a processing speed adjustment process for adjusting the processing speed in the forging process based on the temperature of the mold measured in the mold temperature monitoring process, the processing speed in the forging process becomes too fast. The temperature of the metal material can be prevented from becoming higher than a predetermined processing temperature, and the uniformity of manufacturing conditions is excellent.

Here, the processing speed in the forging process varies depending on the type and composition of the metal material, the shape and dimensions of the parts to be manufactured, etc., but is preferably 100 mm / s to 500 mm / s.
As the processing speed in the forging molding process becomes slower than 100 mm / s, the mass productivity tends to decrease, and as the speed becomes faster than 500 mm / s, the temperature of the metal material is likely to rise and maintain a predetermined processing temperature. Tends to be difficult, and the quality tends to vary.
In the processing speed adjustment process, the processing speed in the forging process is adjusted based on the temperature measured in the mold temperature monitoring process. The temperature measured in the mold temperature monitoring process and the surface inside the mold Since the relationship with the temperature is known in advance, the forging process can be performed at a processing speed suitable for the actual temperature of the metal material inside the mold.

The invention described in claim 3 is the constant temperature forging method according to claim 1 or 2, wherein the temperature measured in the mold temperature monitoring step is the upper mold and / or the lower mold. It has the structure which is the temperature of the surface near side part inside.
With this configuration, in addition to the operation of the first or second aspect, the following operation is provided.
(1) When the temperature measured in the mold temperature monitoring step is the temperature of the upper mold and / or the lower mold, the inner surface temperature of the upper mold and the lower mold. It can measure almost the same temperature and protect the temperature sensor (mold temperature measuring part) such as thermocouple with the mold to prevent contact with metal material. Excellent management reliability.

  Here, the temperature near the surface inside the upper mold and the lower mold is such that an insertion hole is drilled from the outer surface of the upper mold and the lower mold to the inner surface side, and a thermocouple is formed inside the insertion hole. It can be measured by inserting a temperature sensor (mold temperature measuring unit). At this time, if an insertion hole is formed on the inner surface (inner peripheral surface) side of the upper mold and the lower mold, leaving a thick inner wall that can protect a temperature sensor (mold temperature measuring part) such as a thermocouple. Good. In particular, when the inner wall thickness is set so that the surface temperature of the inner wall on the insertion hole side is substantially the same as the inner surface (inner peripheral surface) of the upper mold or lower mold, the mold can be easily and reliably used. The internal surface temperature of the mold can be detected, and the temperature control is reliable and easy.

According to a fourth aspect of the present invention, there is provided a constant temperature forging molding apparatus comprising: a lower mold; an induction heating coil for a lower mold disposed on an outer periphery of the lower mold; and an upper disposed opposite to the lower mold. A mold, an induction heating coil for an upper mold disposed on the outer periphery of the upper mold, a mold temperature measuring unit for measuring the temperature of the upper mold and / or the lower mold, and the mold Based on the temperature measured by the temperature measuring unit, a temperature adjusting unit that adjusts the internal surface temperature of the upper mold and the lower mold to converge and maintain the processing temperature of the metal material, and a preheated metal It has a configuration including a pressurizing unit that sandwiches and pressurizes a material between the upper mold and the lower mold, the temperature of which is adjusted to the processing temperature.
This configuration has the following effects.
(1) Since the induction heating coil for the lower mold and the induction heating coil for the upper mold are arranged on the outer periphery of the lower mold and the upper mold, it is easy to attach and detach to and from the lower mold and the upper mold. In addition, the lower mold and upper mold can be exchanged, and it is excellent in maintenance and handling.
(2) Since it has a mold temperature measuring section that measures the temperature of the upper mold and / or the lower mold, the required temperature of the upper mold and the lower mold can be measured easily and reliably, and the temperature is measured. Excellent certainty.
(3) By having a temperature adjustment unit that adjusts the internal surface temperature of the upper mold and the lower mold to converge and maintain the processing temperature of the metal material based on the temperature measured by the mold temperature measurement unit, Since the temperature of the metal material inside the mold and the metal material in the mold can be kept at the processing temperature of the metal material, the manufacturing conditions during forging can be kept almost constant, and high quality and uniformity with little variation. Excellent forged parts can be manufactured, and quality reliability and mass productivity are excellent.
(4) It is possible to pressurize a metal material while heating it to a desired heating temperature by having a pressurizing unit that pressurizes a metal material that has been preheated by sandwiching the temperature between an upper mold and a lower mold. Therefore, it is possible to reduce the processing pressure and perform high-speed processing, and it is excellent in mass productivity. In addition, the processing pressure can be reduced and the labor saving is excellent, and the pressurizing part can be made compact, and the space saving is excellent.

  Here, the induction heating coil for the lower mold and the induction heating coil for the upper mold are fixed to the outer periphery of the lower mold and the upper mold in a non-contact state, respectively. By disposing an insulating and heat-resistant cushioning material at a location between the inner periphery of the lower die induction heating coil and the upper die induction heating coil and the outer periphery of the lower die and upper die. It is possible to reliably form a gap between the induction heating coil for the lower mold and the induction heating coil for the upper mold and the lower mold and the upper mold, thereby preventing a short circuit from occurring due to the contact between both. it can. As a material of the buffer material, it is only necessary to have heat resistance enough to withstand the heating by the lower mold induction heating coil and the upper mold induction heating coil, and a heat resistant resin is preferably used.

The mold temperature measuring unit is used to measure the temperature of the outer surface of the upper mold and / or the lower mold and the temperature inside the insertion hole drilled from the outer surface (the surface near the inner surface of the upper mold and the lower mold). Any device that can measure (temperature) can be used. The mold temperature measuring unit (temperature sensor) may be a contact type or non-contact type, and a thermocouple, an infrared radiation thermometer, or the like is preferably used. The number and arrangement of the mold temperature measuring units can be appropriately selected according to the size and shape of the mold.
In the temperature adjustment unit, based on the temperature at a predetermined position of the mold measured by the mold temperature measurement unit, an output of a power source that supplies power to the lower mold induction heating coil and the upper mold induction heating coil is output. By adjusting, temperature adjustment is performed so that the internal surface temperatures of the upper mold and the lower mold converge to the set temperature. When equipped with multiple mold temperature measurement units, the temperature distribution of the entire mold can be known from the temperature detected by each mold temperature measurement unit, and the mold can be heated reliably and efficiently without unevenness. Excellent heating uniformity and temperature control reliability.

The invention according to claim 5 is the constant-temperature forging molding device according to claim 4, wherein the contact surface between the lower receiving base on which the lower mold is fixed and the lower mold and / or the upper mold. It has the structure provided with the surface recessed part formed in the contact surface of the upper receiving base to which a type | mold is fixed, and the said upper metal mold | die.
With this configuration, in addition to the operation of the fourth aspect, the following operation is provided.
(1) By having a surface recess formed on the contact surface between the lower receiving base and the lower mold and / or the contact surface between the upper receiving base and the upper mold, the lower receiving base and the upper receiving base and the lower mold are provided. The contact area with the upper mold and the upper mold can be reduced, and an air layer can be formed in the concave portion of the surface, suppressing heat transfer from the lower mold and the upper mold to the lower base and the upper base. In addition, the temperature of the upper mold can be prevented from lowering, and the mold heating efficiency and energy saving are excellent.

  Here, as a material of the lower support base and the upper support base, it is preferable to use a metal such as stainless steel having a high strength, a high impact resistance, and a low thermal conductivity. In addition to being excellent in durability, it is possible to prevent the heat of the lower mold and the upper mold from being absorbed by the lower base and the upper base and to lower the temperature, thereby improving the efficiency of the mold heating.

The surface recess may be formed in the lower receiving base or the upper receiving base, or may be formed in the lower mold or the upper mold. In particular, when forming a surface recess in the lower support base or the upper support base, the surface recess has excellent shape flexibility and workability, and the strength of the lower mold and the upper mold is not reduced, resulting in reliability. Excellent.
The surface concave portion may be formed by arranging a plurality of concave portions having an arbitrary cross-sectional shape such as a circular shape or a polygonal shape, or a plurality of annular groove grooves formed on a concentric circle. May be.
The depth of the surface recess is preferably formed to a depth of 10 mm or less. This is because as the depth of the surface concave portion becomes deeper than 10 mm, the workability is lowered and the strength tends to be insufficient and the durability tends to be lowered.

Invention of Claim 6 is the constant temperature forging molding apparatus of Claim 4 or 5, Comprising: The structure provided with the heat retention ring cyclically | annulated by the outer periphery of the said upper metal mold and / or the said lower metal mold | die. Have.
With this configuration, in addition to the operation of the fourth or fifth aspect, the following operation is provided.
(1) By having a heat retaining ring mounted around the outer periphery of the upper mold and / or the lower mold, heat radiation from the outer peripheral surface of the upper mold and the lower mold can be prevented, and the mold heating Excellent efficiency and energy saving.

  Here, as the material of the heat retaining ring, the same material as the above-described lower receiving base and upper receiving base is preferably used. When the heat retaining ring is fixed to the outer periphery of the mold by shrink fitting, both can be brought into close contact and firmly fixed, and the fixing stability is excellent.

The invention described in claim 7 is the constant temperature forging device according to any one of claims 4 to 6, wherein the contact surface between the heat retaining ring and the upper mold and / or the lower mold. It has the structure provided with the side recessed part formed in this.
With this configuration, in addition to the operation of any one of claims 4 to 6, the following operation is provided.
(1) By having a side recess formed in the contact surface between the heat retaining ring and the upper mold and / or the lower mold, the contact area between the heat retaining ring and the upper mold and the lower mold can be reduced, and the side surface An air layer can be formed in the recess, suppressing heat transfer from the upper mold and lower mold to the heat retaining ring, and effectively preventing temperature drop of the upper mold and lower mold. Efficiency and energy saving can be improved.

Here, the side recesses may be formed on the inner peripheral surface of the heat retaining ring, or may be formed on the outer peripheral surface of the upper mold or the lower mold. In particular, when the side recess is formed in the heat retaining ring, the shape flexibility and workability of the side recess are excellent, and the strength of the upper mold and the lower mold is not reduced, and the reliability is excellent.
The side recess may be formed by arranging a plurality of recesses such as a circular shape or a polygonal shape, or by forming a plurality of rows of concave grooves formed in an annular shape along the circumferential surface in the height direction. May be.
The depth of the side recess formed on the heat retaining ring is preferably formed within 10 mm. This is because as the depth of the side recess becomes deeper than 10 mm, the workability decreases, and the strength tends to be insufficient and the durability tends to decrease.

As described above, according to the constant temperature forging molding method and constant temperature forging molding apparatus of the present invention, the following advantageous effects can be obtained.
According to invention of Claim 1, it has the following effects.
(1) By the mold temperature monitoring process and the heating temperature adjustment process, the temperature of the metal material inside the mold and the metal material in the mold can be maintained at the processing temperature of the metal material. It can be processed at high speed with reduced processing pressure without cooling, can maintain high manufacturing conditions in both winter and summer, can be molded efficiently, and has high quality and uniformity with little variation. It is possible to provide a constant temperature forging molding method excellent in quality reliability, mass productivity, production efficiency, and stability capable of producing a forged molded part excellent in quality.
(2) In the material heating step, the metal material once solutionized is heated to 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 ° C. or higher and below the recrystallization temperature of the metal material, and then the heating temperature adjustment step. Producing high-strength, high-toughness, high-quality forged parts by putting them into a mold that has been adjusted to the processing temperature and performing the forging process, thereby simultaneously realizing grain refinement and precipitation hardening. As in the past, there is no need for additional heat treatment after the forging process, and it can be molded into a shape that is close to the final shape of the product, and no post-processing such as cutting is required. It is possible to provide a constant temperature forging molding method that can be significantly reduced and that can improve the material yield and is excellent in mass productivity and resource saving.

According to invention of Claim 2, in addition to the effect of Claim 1, it has the following effects.
(1) In the process speed adjustment process of the forging process, the process speed can be appropriately adjusted based on the mold temperature measured in the mold temperature monitoring process, and the process speed in the forge process is increased. Thus, it is possible to provide a constant temperature forging method excellent in uniformity of manufacturing conditions that can surely prevent the temperature of the metal material from becoming higher than a predetermined processing temperature.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2, it has the following effects.
(1) While the temperature sensor (mold temperature measuring part) such as a thermocouple is surely prevented from coming into contact with the metal material, the surface inside the mold is almost equal to the inner surface temperature of the upper mold and the lower mold. It is possible to provide a constant-temperature forging molding method excellent in temperature measurement reliability and temperature management reliability capable of measuring the temperature of the side portion.

According to invention of Claim 4, it has the following effects.
(1) Based on the temperature measured by the mold temperature measuring unit, the temperature adjusting unit can maintain the temperature inside the mold and the temperature of the metal material in the mold at the set processing temperature, and manufacturing conditions at the time of forging It is possible to provide a constant temperature forging molding apparatus excellent in quality reliability and mass productivity capable of producing a forged molded part having a high quality and excellent uniformity with little variation.
(2) The processing pressure is reduced by pressurizing at the pressurizing part while holding the metal material between the upper and lower molds maintained at the set processing temperature and heating to a substantially constant processing temperature. It is possible to provide a constant temperature forging molding apparatus that can perform high-speed processing, is excellent in mass productivity and labor saving, can be made compact in the pressing portion, and is excellent in space saving.

According to invention of Claim 5, in addition to the effect of Claim 4, it has the following effects.
(1) By forming a concave surface on the contact surface between the lower receiving base and the lower mold and / or the contact surface between the upper receiving base and the upper mold, the lower receiving base, the upper receiving base and the lower mold or the upper mold are formed. The contact area with the mold can be reduced, and an air layer can be formed in the concave portion on the surface, suppressing heat transfer from the lower mold or upper mold to the lower receiving base or upper receiving base. It is possible to provide a constant-temperature forging molding apparatus that is excellent in the efficiency and energy saving of mold heating that can prevent the temperature of the mold from decreasing.

According to invention of Claim 6, in addition to the effect of Claim 4 or 5, it has the following effects.
(1) The efficiency of mold heating, which can prevent heat dissipation from the outer peripheral surface of the upper mold and the lower mold by mounting a heat retaining ring on the outer periphery of the upper mold and / or the lower mold, It is possible to provide a constant temperature forging molding device that is excellent in energy saving.

According to invention of Claim 7, in addition to the effect of any one of Claims 4 thru | or 6, it has the following effects.
(1) By forming a side recess in the contact surface between the heat retaining ring and the upper mold and / or the lower mold, the contact area between the heat retaining ring and the upper mold and the lower mold can be reduced, and the side recess An air layer can be formed, heat transfer from the upper mold and lower mold to the heat retaining ring can be suppressed, and temperature drop of the upper mold and lower mold can be effectively prevented, and the mold heating efficiency It is possible to provide a constant-temperature forging molding apparatus excellent in mass productivity that can improve the performance and energy saving.

The constant temperature forging molding method and constant temperature forging molding apparatus of the present invention will be described below with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view of an essential part showing a configuration of a constant temperature forging molding apparatus used in the constant temperature forging molding method according to the first embodiment.
In FIG. 1, 1 is a constant temperature forging molding apparatus according to the first embodiment, 2 is a lower mold base of the constant temperature forging molding apparatus 1, and 3 is a lower receiver of the constant temperature forging molding apparatus 1 disposed on the upper surface side of the lower mold base 2. A base 4 is a lower mold fixed to the upper surface of the lower receiving base 3 by a fixing ring 4 a, 4 b is a heat retaining ring fixed to the outer periphery of the lower mold 4, and 4 c is an inner surface from the outer peripheral surface of the lower mold 4. Thermocouple insertion hole 5 drilled toward the peripheral surface side, 5 is an induction heating coil for a lower mold of the constant temperature forging molding apparatus 1 disposed on the outer periphery of the lower mold 4, and 5 a is an outer periphery of the lower mold 4. Cushioning material disposed at a point between the induction heating coil 5 and the lower mold induction coil 5, 6 is an upper base of the constant temperature forging molding apparatus 1 disposed opposite to the lower mold base 2, and 7 is a lower surface of the upper base 6. An upper receiving base 8 of the constant temperature forging molding device 1 disposed on the side is fixed to the lower surface of the upper receiving base 7 by a fixing ring 8a. Upper mold, 8b is a heat retaining ring fixed to the outer periphery of the upper mold 8, 8c is a thermocouple insertion hole drilled from the outer peripheral surface of the upper mold 8 toward the inner peripheral surface side, and 9 is the upper mold An induction heating coil 9a for the upper mold of the constant temperature forging molding apparatus 1 disposed on the outer periphery of the mold 8 is disposed at a point between the outer periphery of the upper mold 8 and the induction heating coil 9 for the upper mold. The buffer material 10 is connected to the lower mold induction heating coil 5 and the upper mold induction heating coil 9 by the high frequency cable 10a and supplies power, and 11a and 11b are inserted into the thermocouple insertion holes 4c and 8c. A mold internal temperature measuring section as a mold temperature measuring section of the constant temperature forging molding apparatus 1 for measuring the temperature of the inner side of the lower mold 4 and the upper mold 8 by means of a thermocouple, and 12 is the inside of the mold. The internal surface temperatures of the lower mold 4 and the upper mold 8 based on the temperatures measured by the temperature measuring units 11a and 11b A temperature adjusting unit 13 that adjusts the output of the power supply 10 so as to converge and maintain the set processing temperature of the metal material 20, and a lower mold 4 that is adjusted in advance to the processing temperature of the preheated metal material 20 and the upper mold The pressurizing part of the constant temperature forging molding apparatus 1 that is sandwiched and pressed by the mold 8, 13 a is a punch of the pressurizing part 13, and 13 b is a knockout pin of the pressurizing part 13.

Next, the structure of the base of the constant temperature forging molding apparatus according to Embodiment 1 will be described.
FIG. 2 is a schematic perspective view of a receiving base of the constant temperature forging molding apparatus according to the first embodiment.
In FIG. 2, 3A is a surface recess formed by disposing a plurality of recesses 3a having a circular cross section or a polygonal cross section on the contact surface of the lower base 3 with the lower mold 4; 13 is a through hole for inserting 13 punches 13a.
In the present embodiment, the lower base 3 is made of a metal such as stainless steel having high strength and strong impact resistance and low thermal conductivity. This is because it is excellent in durability, and it is possible to prevent the temperature of the lower mold 4 from being absorbed by the lower receiving base 3 to lower the temperature, and to improve the efficiency of mold heating.
The depth of the surface recess 3A (recess 3a) formed on the contact surface with the lower mold 4 was set to a depth of 10 mm or less. This is because, as the depth of the surface recess 3A becomes deeper than 10 mm, the workability deteriorates and the strength tends to be insufficient and the durability tends to decrease. The surface recess 3A (recess 3a) reduces the contact area between the lower base 3 and the lower mold 4, and forms an air layer in the surface concave 3A, and heat from the lower mold 4 to the lower base 3 Transmission was suppressed and the temperature drop of the lower mold 4 could be prevented.

Next, a modified example of the base of the constant temperature forging device of Embodiment 1 will be described.
FIG. 3A is a schematic perspective view showing a modified example of the lower base of the constant temperature forging molding apparatus according to the first embodiment, and FIG. 3B shows the lower base of the constant temperature forging molding apparatus according to the first embodiment. It is a schematic cross section which shows a modification.
The difference between the lower receiving base 3 ′ in the first embodiment and the lower receiving base 3 in the first embodiment is that a plurality of concave grooves 3c formed in an annular shape are arranged on a concentric circle to form a surface concave portion 3B. It is. Thereby, the same operation as the receiving base 3 can be obtained.
Note that the upper receiving base 7 is formed in the same manner as the lower receiving base 3 only by being arranged symmetrically with the lower receiving base 3, and the description thereof will be omitted.

  In the present embodiment, the surface recess 3A (recess 3a) is formed in the lower receiving base 3 and the upper receiving base 7. However, the contact surfaces between the heat retaining rings 4b and 8b and the lower mold 4 and the upper mold 8 are also side surfaces. A recess can be formed. As a result, the contact area between the heat retaining rings 4b, 8b and the lower mold 4 and the upper mold 8 can be reduced, and an air layer can be formed in the side recess, and the heat retaining from the lower mold 4 and the upper mold 8 can be achieved. It is possible to suppress heat transfer to the rings 4b and 8b, to effectively prevent a temperature drop of the lower mold 4 and the upper mold 8, and to improve the efficiency and energy saving of the mold heating.

Next, the attachment structure of the induction heating coil for the lower mold of the constant temperature forging molding apparatus of Embodiment 1 will be described.
FIG. 4 is a schematic plan view of a main part showing a mounting structure of an induction heating coil for a lower mold of the constant temperature forging molding apparatus according to the first embodiment.
In FIG. 4, reference numeral 5 b denotes a coil mounting portion for fixing the lower mold induction heating coil 5 to the lower mold 4 by screwing.
When the induction heating coil 5 for the lower mold is fixed by the coil mounting portion 5b, a buffer material 5a having insulation and heat resistance is arranged between the outer periphery of the lower mold 4 and the induction heating coil 5 for the lower mold. By providing, a gap can be surely formed between the induction heating coil 5 for the lower mold and the lower mold 4, and it is possible to prevent both from coming into contact and causing a short circuit. In the present embodiment, the heat-resistant resin is used as the buffer material 5a. However, the buffer material 5a only needs to have heat resistance enough to withstand the heating by the lower mold induction heating coil 5.
The upper mold induction heating coil 9 is fixed in the same manner as the lower mold induction heating coil 5, and thus the description thereof is omitted.

Based on the operation of the constant temperature forging molding apparatus configured as described above, the constant temperature forging molding method of the first embodiment will be described.
First, in FIG. 1, the lower mold 4 and the upper mold 8 are heated by the lower mold induction heating coil 5 and the upper mold induction heating coil 9 in the mold heating step.
When heating of the lower mold 4 and the upper mold 8 is started, the mold inner temperature measuring units 11a and 11b perform near-surface portions inside the lower mold 4 and the upper mold 8 in the mold temperature monitoring step. Measure and monitor the temperature.
Next, the heating temperature adjustment step adjusts the output of the power supply 10 at the temperature adjustment unit 12 so that the inner surface temperature of the die converges to the processing temperature based on the temperature measured in the die temperature monitoring step, The heating temperature in the mold heating process is adjusted.
In order to optimize the mold internal surface temperature in contact with the product part (metal material 20), the positions of the mold internal temperature measuring units 11a and 11b are set, and the heating temperature is adjusted by the heating temperature adjusting process. ing. Therefore, the position and number of the mold internal temperature measuring units 11a and 11b are not limited to the present embodiment, and depending on the shape, size, set temperature, etc. of the lower mold 4 and the upper mold 8, It can select suitably.

When the mold inner surface temperatures of the lower mold 4 and the upper mold 8 converge to the processing temperature by the heating temperature adjusting process, the metal material 20 is put into the mold in the forging process, and the lower mold 4 and the upper mold are placed. The metal material 20 sandwiched by the mold 8 is forged by the punch 13a of the pressurizing unit 13. The metal material 20 is obtained by heating the previously melted metal material 20 at 150 ° C. or more and below the recrystallization temperature of the metal material 20 in the material heating process before being put into the mold in the forging process. . This is because the metal material 20 once solutionized is heated to a temperature below the recrystallization temperature and subjected to isothermal forging, so that precipitation hardening occurs simultaneously with refinement of crystal grains.
When the forging is finished, the product is taken out from the mold by the knockout pin 13b.
Hereinafter, the temperature of each part of the lower mold 4 and the upper mold 8 is measured and monitored by the mold temperature monitoring process, and the mold internal surface temperature of the lower mold 4 and the upper mold 8 is set to the processing temperature by the heating temperature adjusting process. While holding, the forging process is repeated.

The temperature (processing temperature) of the metal material 20 in the forging process varies depending on the type and composition of the material, but is 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 ° C. or higher. It was as follows. As the temperature of the metal material 20 in the forging process becomes lower than 150 ° C., the moldability tends to decrease, and as the recrystallization temperature becomes higher, the grain size of the crystal grains becomes larger and the strength becomes higher. This is because it has been found that the toughness tends to decrease. Also, if the temperature of the metal material in the forging process becomes lower than 120 ° C or 100 ° C, depending on the type of metal material and the size of the product, the physical properties will deteriorate significantly, and complex shapes will be molded. Found out that it tends to be difficult.
For example, when an aluminum alloy (A6061) is processed as the metal material 20, the temperature (processing temperature) of the metal material 20 and the inside (inner surface) of the lower mold 4 and the upper mold 8 is about 100 ° C. to 300 ° C. Thus, temperature adjustment was performed in the heating temperature adjustment process.
In addition, when it has the process speed adjustment process which adjusts the process speed in a forge molding process based on the temperature measured at a metal mold | die temperature monitoring process, the process speed in a forge molding process becomes too fast, and the metal raw material 20 The temperature can be prevented from becoming higher than a predetermined processing temperature, and the uniformity of manufacturing conditions is excellent.
The pressurizing unit 13 can also control the number of pressurizations by an electrical signal from the temperature adjusting unit 12.

As described above, the constant temperature forging molding method according to Embodiment 1 has the following effects.
(1) Measured in a mold heating process for heating the upper mold and the lower mold, a mold temperature monitoring process for measuring and monitoring the temperature of the upper mold and / or the lower mold, and a mold temperature monitoring process. By having a heating temperature adjustment process that adjusts the heating temperature in the mold heating process so that the surface temperature inside the mold converges and maintains the processing temperature of the metal material based on the temperature, the inside of the mold and the inside of the mold Since the temperature of the metal material can be maintained at a predetermined processing temperature, the manufacturing conditions in the subsequent forging process can be kept substantially constant, and forged parts with high quality and excellent uniformity with little variation. It can be manufactured and has excellent quality reliability and mass productivity.
(2) Since there is a forging process in which the metal material heated in advance in the material heating process is put into a mold whose temperature has been adjusted to the processing temperature in the heating temperature adjustment process and forged, the metal material will not cool down. The processing pressure can be reduced and high-speed processing can be performed, and the mass productivity is excellent. In addition, it can be efficiently molded under substantially constant conditions regardless of winter or summer, and is excellent in production efficiency and stability.
(3) A material heating step for heating the solution-treated metal material to 100 ° C or higher, preferably 120 ° C or higher, more preferably 150 ° C or higher and below the recrystallization temperature of the metal material, and metal heated in the material heating step Grain refinement and precipitation performed separately in conventional cold forging by having a forging molding process in which the raw material is put into a mold whose temperature is adjusted to the processing temperature in the heating temperature adjusting process and forged. It can be cured at the same time, and can produce high-strength, high-toughness, high-quality forged parts without additional heat treatment after the forging process, and the shape is close to the final shape of the product Therefore, post-processing such as cutting is not required, the number of processing steps can be greatly reduced, the material yield can be improved, and mass productivity and resource saving are excellent.
(4) The temperature measured in the mold temperature monitoring step is the temperature of the upper surface of the upper mold and the lower mold, and is almost equal to the internal surface temperature of the upper mold and the lower mold. In addition to measuring the temperature, the mold temperature internality measurement part using a thermocouple can be protected by a mold to prevent contact with metal materials. Reliability of temperature measurement and reliability of temperature management Excellent in properties.

As described above, the constant temperature forging molding apparatus according to Embodiment 1 has the following effects.
(1) Since the induction heating coil for the lower mold and the induction heating coil for the upper mold are arranged on the outer periphery of the lower mold and the upper mold, it is easy to attach and detach to and from the lower mold and the upper mold. In addition, the lower mold and upper mold can be exchanged, and it is excellent in maintenance and handling.
(2) Mold internal temperature measurement unit that measures the temperature of the inner surface of the upper mold and the lower mold and the mold outer surface temperature measurement unit that measures the outer surface temperature of the lower mold and the upper mold Therefore, the required temperature of the upper mold and the lower mold can be measured easily and surely, and the reliability of temperature measurement is excellent.
(3) By having a temperature adjustment unit that adjusts the internal surface temperature of the upper mold and the lower mold to converge and maintain the processing temperature of the metal material based on the temperature measured by the mold temperature measurement unit, Since the temperature of the metal material inside the mold and the metal material in the mold can be kept at the processing temperature of the metal material, the manufacturing conditions during forging can be kept almost constant, and high quality and uniformity with little variation. Excellent forged parts can be manufactured, and quality reliability and mass productivity are excellent.
(4) It is possible to pressurize a metal material while heating it to a desired heating temperature by having a pressurizing unit that pressurizes a metal material that has been preheated by sandwiching the temperature between an upper mold and a lower mold. Therefore, it is possible to reduce the processing pressure and perform high-speed processing, and it is excellent in mass productivity. In addition, the processing pressure can be reduced and the labor saving is excellent, and the pressurizing part can be made compact, and the space saving is excellent.
(5) By having a surface recess formed on the contact surface between the lower receiving base and the lower mold and / or the contact surface between the upper receiving base and the upper mold, the lower receiving base and the upper receiving base and the lower mold are provided. The contact area with the upper mold and the upper mold can be reduced, and an air layer can be formed in the concave portion of the surface, suppressing heat transfer from the lower mold and the upper mold to the lower base and the upper base. In addition, the temperature of the upper mold can be prevented from lowering, and the mold heating efficiency and energy saving are excellent.
(6) By having a heat retaining ring mounted around the outer periphery of the upper mold and / or the lower mold, heat radiation from the outer peripheral surface of the upper mold and the lower mold can be prevented, Excellent efficiency and energy saving.

Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples.
The constant temperature forging molding was performed by the constant temperature forging molding method and the constant temperature forging molding apparatus described in the first embodiment.
As a metal material, a solution obtained by solution treatment of aluminum alloy (A6061-T6 material) (heated at 530 ° C. for 1 hour and then water-cooled) is heated to 170 ° C. (recrystallization temperature or lower) and used at a compression rate of 50% to Molded at 70%.
Moreover, temperature adjustment was performed in the heating temperature adjustment process so that the internal surface temperatures of the metal material, the lower mold, and the upper mold were about 100 ° C to 300 ° C.
A test piece was collected from the molded product thus obtained, and 0.2% proof stress, tensile strength, and elongation were measured in accordance with JIS Z 2241 “Tensile test method for metal material”.
As a result, 0.2% proof stress 310~320N / mm ^2, tensile strength 330~340N / mm ^2, elongation was 13 to 16%.
0.2% proof stress of the conventional forged product, tensile strength, the JIS standard value of elongation, ^{respectively> 245N / mm 2,> 265N} / mm 2,> was 10% in the present embodiment, both JIS The result was much higher than the standard value.
From the above results, it was found that according to this example, a mechanical strength exceeding that was obtained without performing the heat treatment after forging as in the prior art. In addition, it has been difficult to combine strength and flexibility with a conventional forged product, but according to the present example, it has been found that a forged product having excellent strength and flexibility can be realized. These results are thought to be because crystal refinement and precipitation hardening are performed simultaneously.

  The present invention is capable of easily and reliably maintaining the temperature of the material in the mold at a predetermined temperature, maintaining the processing speed at the time of forging appropriately, and heating the material to a predetermined temperature or higher. Can be reliably prevented, crystal grains can be refined, high strength, toughness and high quality parts can be processed at high speed, no post-processing heat treatment is required, and post-processing can be minimized Providing a constant temperature forging method with excellent mass productivity, simple structure, excellent heat insulation, reduced heat dissipation from the mold, excellent mold heating efficiency, reliable material in the mold In addition to being excellent in moldability and processing uniformity, it is possible to reduce the size by reducing the applied pressure, enabling high-speed processing, and reliability and durability with little variation. For high-quality, high-quality forged parts By providing a constant temperature forging molding equipment, it is possible to stably supply high-quality light metal parts such as aluminum alloys, and to improve the quality of various metal parts such as automobiles, power equipment, and housing-related equipment. , Can contribute to weight reduction.

Cross-sectional schematic diagram of relevant parts showing the configuration of a constant-temperature forging molding apparatus used in the constant-temperature forging molding method of Embodiment 1 Schematic perspective view of the base of the constant temperature forging molding device of Embodiment 1 (A) Schematic perspective view showing a modification of the base of the constant temperature forging molding apparatus of Embodiment 1 (b) Schematic cross-sectional view showing a modification of the base of the constant temperature forging molding apparatus of Embodiment 1 Schematic plan view of relevant parts showing a structure for mounting an induction heating coil for a lower mold of the constant temperature forging molding apparatus according to Embodiment 1

DESCRIPTION OF SYMBOLS 1 Constant temperature forging molding apparatus 2 Lower die base 3, 3 'Lower receiving base 3a Recess 3A, 3B Surface recess 3b Through-hole 3c Recess groove 4 Lower mold 4a, 8a Fixing ring 4b, 8b Heat retaining ring 4c, 8c Thermocouple insertion Hole 5 Induction heating coils 5a and 9a for lower molds Buffer material 5b Coil mounting part 6 Upper base 7 Upper receiving base 8 Upper mold 9 Induction heating coil 10 for upper molds Power supply 10a High-frequency cables 11a and 11b Measurement of mold internal temperature Part 12 Temperature adjustment part 13 Pressurization part 13a Punch 13b Knockout pin

Claims (7)

It is measured by a mold heating process for heating the upper mold and the lower mold, a mold temperature monitoring process for measuring and monitoring the temperature of the upper mold and / or the lower mold, and the mold temperature monitoring process. Based on the temperature, a heating temperature adjusting step of adjusting the heating temperature in the mold heating step so as to converge and maintain the surface temperature inside the mold to the processing temperature of the metal material, and the solution-formed metal material 100 A material heating process that heats the metal material to a recrystallization temperature not lower than ℃ and the metal material heated in the material heating process is put into a mold whose temperature is adjusted to the processing temperature in the heating temperature adjustment process. And a forging and molding process for forging and molding, and a constant temperature forging and molding method. The constant temperature forging molding method according to claim 1, further comprising a processing speed adjustment step of adjusting a processing speed in the forging molding step based on the temperature measured in the mold temperature monitoring step. 3. The constant temperature according to claim 1, wherein the temperature measured in the mold temperature monitoring step is a temperature of a portion near a surface inside the upper mold and / or the lower mold. Forging molding method. A lower mold, a lower mold induction heating coil disposed on the outer periphery of the lower mold, an upper mold disposed to face the lower mold, and an outer periphery of the upper mold An upper mold induction heating coil, a mold temperature measuring unit for measuring the temperature of the upper mold and / or the lower mold, and the upper mold based on the temperature measured by the mold temperature measuring unit A temperature adjusting unit that adjusts the inner surface temperature of the mold and the lower mold so as to converge and maintain the processing temperature of the metal material, and the upper mold whose temperature of the preheated metal material is adjusted to the processing temperature, A constant temperature forging molding apparatus comprising: a pressurizing unit that sandwiches and pressurizes the lower mold. A surface formed on a contact surface between the lower receiving base and the lower mold on which the lower mold is fixed and / or on a contact surface between the upper receiving base and the upper mold on which the upper mold is fixed. The constant temperature forging molding apparatus according to claim 4, further comprising a recess. The constant temperature forging molding apparatus according to claim 4 or 5, further comprising a heat retaining ring provided around an outer periphery of the upper mold and / or the lower mold. The side surface recessed part formed in the contact surface of the said heat retaining ring, the said upper metal mold | die, and / or the said lower metal mold | die is provided, The any one of the Claims 4 thru | or 6 characterized by the above-mentioned. Constant temperature forging molding equipment.

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