KR20220151605A - Molding device and molding method - Google Patents

Abstract

The molding apparatus is a molding apparatus for molding a heated metal material, and includes a mold for performing quench molding by contacting the metal material, and a cooling part for cooling the mold, and the cooling part is used to accumulate heat in the mold by repeated molding. Therefore, the decrease in hardenability of the metal material is suppressed.

Description

Molding device and molding method

One aspect of the present invention relates to a molding apparatus and a molding method.

BACKGROUND OF THE INVENTION [0002] Conventionally, a molding apparatus for molding a heated metal material is known. For example, in Patent Document 1 below, a mold having a lower mold and an upper mold paired with each other, a gas supply unit for supplying gas into a metal pipe material supported between the molds, and heating the metal pipe material by electric heating A molding apparatus having a heating unit is disclosed. Such a molding apparatus includes a cooling unit that flows water into a flow path formed in a mold in order to cool the heated metal pipe during molding. In this way, the forming apparatus can perform quench molding by bringing the cooled mold into contact with the metal pipe material.

Patent Document 1: Japanese Unexamined Patent Publication No. 2009-220141

[0012] The forming apparatus as in the prior art performs new hardening and forming of a heated metal material when the quenching and shaping of the heated metal material is completed. In this way, the forming apparatus repeatedly performs quenching and forming of the heated metal material. That is, the mold repeatedly contacts the metal material in a high-temperature state. In contrast, conventionally, when the cooling unit cools the mold, it has not been considered that repeated molding is performed. In this case, heat is gradually accumulated in the mold, and there is a possibility that the hardenability of the metal material is lowered. This causes a problem that the stability of the quality of the molded article, such as hardenability and moldability, is lowered when repeated molding is performed.

One aspect of the present invention has been made to solve such a problem, and an object of one aspect of the present invention is to provide a molding apparatus and a molding method capable of improving the stability of the quality of molded products in the case of repeated molding. is to provide

A molding apparatus according to one aspect of the present invention is a molding apparatus for molding a heated metal material, and includes a mold for performing quench molding by contacting the metal material, and a cooling section for cooling the mold, wherein the cooling section is formed by repeated molding. A decrease in hardenability of a metal material due to heat accumulation in the mold is suppressed.

Such a molding apparatus has a mold that performs quench molding by contacting a metal material. When the mold and the heated metal material come into contact with each other, the temperature of the mold rises. On the other hand, by cooling the mold by the cooling unit, the mold can be brought into a state capable of quench molding. In addition, the cooling section suppresses a decrease in hardenability of the metal material due to heat accumulation in the mold due to repeated molding. Therefore, even if the mold repeatedly receives heat input from the metal material by repeating molding, the mold can perform repeated hardening and molding without deteriorating hardenability. From the above, the molding apparatus can improve the stability of the quality of the molded article in the case of repeated molding.

The cooling unit may converge the temperature of the mold within a predetermined range. In this case, the cooling unit can make the temperature change pattern of the mold during molding close to a constant. Therefore, the molding apparatus can improve the stability of the quality of molded products.

The cooling unit may increase the cooling capacity as the number of molding of the mold increases. As the number of molding times of the mold increases, heat is more likely to accumulate in the mold. Therefore, the cooling unit can suppress the accumulation of heat in the mold by increasing the cooling capacity as the number of molding of the mold increases.

The cooling unit may increase the cooling capacity as the molding time of the mold increases. The longer the molding time of the mold, the easier it is for heat to accumulate in the mold. Therefore, the cooling unit increases the cooling capacity as the molding time of the mold increases, so that heat accumulation in the mold can be suppressed.

The molding apparatus may include a temperature sensor that detects the temperature of the mold, and the cooling unit may adjust the cooling capacity based on the detection result of the temperature sensor. In this case, the cooling unit can bring the mold to an appropriate temperature according to the temperature of the mold.

A molding apparatus according to one aspect of the present invention is a molding apparatus for molding a heated metal material, and includes a mold for performing quench molding by contacting the metal material, and a cooling section for cooling the mold, wherein the cooling section removes heat generated from the mold (拔heat amount, heat removal amount) is made larger than the amount of heat input from the metal material to the mold.

Such a molding apparatus has a mold that performs quench molding by contacting a metal material. When the mold and the heated metal material come into contact with each other, the temperature of the mold tends to rise. On the other hand, by cooling the mold by the cooling unit, the mold can be brought into a state capable of quench molding. Further, the cooling section makes the amount of heat taken from the mold higher than the amount of heat input from the metal material to the mold. In this case, the cooling unit can suppress an increase in the temperature of the mold or reduce the increased temperature of the mold. In this way, in the case of repeated molding, it is possible to suppress a change in hardenability due to an excessive increase in the temperature of the mold. From the above, the molding apparatus can improve the stability of the quality of the molded article in the case of repeated molding.

A molding method according to one aspect of the present invention is a molding method for molding a heated metal material, comprising a molding step of performing quench molding by bringing the metal material into contact with a mold, and a cooling step of cooling the mold. In the cooling step, , The decrease in hardenability of the metal material due to the accumulation of heat in the mold due to repeated molding may be suppressed.

According to this molding method, the same effects and effects as those of the molding apparatus described above can be obtained.

A molding method according to one aspect of the present invention is a molding method for molding a heated metal material, comprising a molding step of performing quench molding by bringing the metal material into contact with a mold, and a cooling step of cooling the mold. In the cooling step, , the amount of heat taken from the mold is made larger than the amount of heat input from the metal material to the mold.

According to this molding method, the same effects and effects as those of the molding apparatus described above can be obtained.

According to one aspect of the present invention, it is possible to provide a molding apparatus capable of improving the stability of the quality of molded products in the case of repeated molding.

1 is a schematic diagram of a molding apparatus according to an embodiment of the present invention.
Fig. 2 is an enlarged sectional view showing the state of a metal pipe material and a mold during blow molding.
3 is a plan view of the mold.
4 is a plan view of the mold showing a state in which the first member is removed.
Fig. 5 is a cross-sectional view taken along line VV shown in Fig. 3;
Fig. 6 is a cross-sectional view taken along line VI-VI shown in Fig. 5;
7 is an enlarged view of a flow path.
8 is a graph showing the relationship between time and mold temperature change.
9 is a graph showing the relationship between time and mold temperature change.
Fig. 10 is a cross-sectional view showing a mold of a molding apparatus according to a modified example.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described, referring drawings. However, the same reference numerals are assigned to the same parts or equivalent parts in each drawing, and overlapping descriptions are omitted.

1 is a schematic diagram of a molding apparatus 1 according to this embodiment. As shown in Fig. 1, a forming apparatus 1 is an apparatus for forming a hollow metal pipe by blow molding. In this embodiment, the molding apparatus 1 is installed on a horizontal surface. The molding apparatus 1 includes a molding mold 2, a drive mechanism 3, a support part 4, a heating part 5, a fluid supply part 6, a cooling part 7, and a control unit ( 8) is provided. However, in this specification, the metal pipe refers to the hollow article after completion of molding in the molding apparatus 1, and the metal pipe material 40 (metal material) refers to the hollow article before completion of molding in the molding apparatus 1. points to The metal pipe material 40 is a pipe material of a type of steel that can be quenched. Among the horizontal directions, the direction in which the metal pipe material 40 extends during molding is sometimes referred to as the "longitudinal direction", and the direction orthogonal to the longitudinal direction is sometimes referred to as the "width direction".

The molding mold 2 is a mold for molding the metal pipe material 40 into a metal pipe, and includes a lower mold 11 and an upper mold 12 that oppose each other in the vertical direction. The lower mold 11 and the upper mold 12 are composed of steel blocks. Each of the lower mold 11 and the upper mold 12 is provided with a concave portion in which the metal pipe material 40 is accommodated. The lower mold 11 and the upper mold 12 are in close contact with each other (mold closed state), and each concave portion forms a space of a target shape in which the metal pipe material is to be molded. Therefore, the surface of each concave portion becomes a molding surface of the molding die 2 . The lower mold 11 is fixed to the base 13 via a die holder or the like. The upper mold 12 is fixed to the slide of the drive mechanism 3 via a die holder or the like.

The drive mechanism 3 is a mechanism that moves at least one of the lower mold 11 and the upper mold 12 . In FIG. 1 , the drive mechanism 3 has a configuration in which only the upper mold 12 is moved. The driving mechanism 3 includes a slide 21 that moves the upper mold 12 so that the lower mold 11 and the upper mold 12 are in contact with each other, and a force that pulls the slide 21 upward. A pull-back cylinder 22 as an actuator that generates, a main cylinder 23 as a drive source for pressing down the slide 21, and a drive source 24 for imparting a driving force to the main cylinder 23, have.

The support part 4 is a mechanism for supporting the metal pipe material 40 disposed between the lower mold 11 and the upper mold 12 . The support portion 4 includes a lower electrode 26 and an upper electrode 27 that support the metal pipe material 40 at one end side in the longitudinal direction of the molding mold 2, and the molding mold 2 Equipped with a lower electrode 26 and an upper electrode 27 for supporting the metal pipe material 40 at the other end side in the longitudinal direction. The lower electrodes 26 and upper electrodes 27 on both sides in the longitudinal direction support the metal pipe material 40 by sandwiching the vicinity of the ends of the metal pipe material 40 from the vertical direction. However, grooves having a shape corresponding to the outer circumferential surface of the metal pipe material 40 are formed on the upper surface of the lower electrode 26 and the lower surface of the upper electrode 27 . A driving mechanism (not shown) is provided on the lower electrode 26 and the upper electrode 27, and can move in the vertical direction independently of each other.

The heating unit 5 heats the metal pipe material 40 . The heating unit 5 is a mechanism that heats the metal pipe material 40 by applying electricity to the metal pipe material 40 . The heating unit 5 is between the lower mold 11 and the upper mold 12, in a state where the metal pipe material 40 is separated from the lower mold 11 and the upper mold 12, The metal pipe material 40 is heated. The heating unit 5 includes the lower electrodes 26 and upper electrodes 27 on both sides in the above-described longitudinal direction, and a power source 28 that sends current to the metal pipe material through these electrodes 26 and 27. do. However, the heating unit may be disposed in a pre-process of the molding apparatus 1 and heated from the outside.

The fluid supply unit 6 is a mechanism for supplying high-pressure fluid into the metal pipe material 40 supported between the lower mold 11 and the upper mold 12. The fluid supply unit 6 supplies high-pressure fluid to the metal pipe material 40, which is in a high-temperature state by being heated by the heating unit 5, to expand the metal pipe material 40. Fluid supply units 6 are provided at both ends of the mold 2 in the longitudinal direction. The fluid supply unit 6 includes a nozzle 31 for supplying fluid to the inside of the metal pipe material 40 from the opening of the end of the metal pipe material 40, and the nozzle 31 to the metal pipe material 40. A drive mechanism 32 for moving back and forth with respect to the opening, and a supply source 33 for supplying high-pressure fluid into the metal pipe material 40 through the nozzle 31 are provided. The drive mechanism 32 brings the nozzle 31 into close contact with the end of the metal pipe material 40 in a state in which sealing properties are secured during fluid supply and exhaust, and the nozzle 31 is attached to the metal pipe material in other cases. It is separated from the end of (40). However, the fluid supply unit 6 may supply gas such as high-pressure air or inert gas as a fluid. In addition, the fluid supply unit 6 may include a heating unit 5 together with the support unit 4 having a mechanism for moving the metal pipe material 40 in the vertical direction, and may be the same device.

The cooling unit 7 is a mechanism for cooling the molding die 2 . The cooling unit 7 can rapidly cool the metal pipe material 40 when the expanded metal pipe material 40 contacts the molding surface of the molding mold 2 by cooling the molding mold 2. . The cooling unit 7 includes a flow path 36 formed inside the lower mold 11 and the upper mold 12, and a circulation mechanism 37 for supplying and circulating a cooling medium through the flow path 36. .

The controller 8 is a device that controls the entire molding apparatus 1. The control unit 8 controls the drive mechanism 3, the support unit 4, the heating unit 5, the fluid supply unit 6, and the cooling unit 7. The controller 8 repeatedly performs the operation of molding the metal pipe material 40 with the molding die 2 .

Specifically, the control unit 8 controls the transfer timing from a transfer device such as, for example, a robot arm, so that the metal pipe material ( 40) is placed. Alternatively, the controller 8 may wait for the operator to manually place the metal pipe material 40 between the lower mold 11 and the upper mold 12. In addition, the controller 8 supports the metal pipe material 40 with the lower electrodes 26 on both sides in the longitudinal direction, then lowers the upper electrode 27 to sandwich the metal pipe material 40 therebetween. So, the actuator of the support part 4 is controlled. Further, the control unit 8 controls the heating unit 5 to energize and heat the metal pipe material 40 . As a result, an axial current flows through the metal pipe material 40, and the metal pipe material 40 itself generates heat by Joule heat due to the electrical resistance of the metal pipe material 40 itself.

The control unit 8 controls the drive mechanism 3 to lower the upper mold 12 and bring it closer to the lower mold 11 to close the molding mold 2 . On the other hand, the control unit 8 controls the fluid supply unit 6 to supply fluid to the nozzle 31 while sealing the openings at both ends of the metal pipe material 40 . As a result, the metal pipe material 40 softened by heating expands and contacts the molding surface of the molding mold 2 . Then, the metal pipe material 40 is molded so as to conform to the shape of the molding surface of the molding mold 2 . However, in the case of forming a flanged metal pipe, after entering a part of the metal pipe material 40 into the gap between the lower mold 11 and the upper mold 12, the mold is further closed, The entry portion is pressed and crushed to obtain a flange portion. When the metal pipe material 40 contacts the molding surface, the metal pipe material 40 is quenched by being quenched by the cooling part 7 in the cooling mold 2 . Such a cooling method is called mold contact cooling or mold cooling. Immediately after rapid cooling, austenite transforms into martensite (hereinafter, transformation of austenite into martensite is referred to as martensite transformation). In the latter half of cooling, since the cooling rate is low, martensite is transformed into other structures (trustite, sorbite, etc.) by reheating. Therefore, it is not necessary to perform a separate tempering process. However, details of control of the cooling unit 7 by the control unit 8 will be described later.

Referring to Fig. 2, the molding procedure of the molding apparatus 1 will be described. As shown in (a) of FIG. 2 , the control unit 8 closes the molding mold 2 and supplies fluid to the metal pipe material 40 from the fluid supply unit 6, thereby performing blow molding. (1st blow). In the primary blow, the control unit 8 molds the pipe portion 43 in the main cavity portion MC and causes the portion corresponding to the flange portion 44 to enter the subcavity portion SC. And, as shown in (b) of FIG. 2, the control part 8 further crushes the part which entered the subcavity part SC by further mold-closing the molding mold 2, and the flange part 44 ) is molded. Next, the controller 8 lifts the upper mold 12 and separates it from the metal pipe material 40 to open the mold. As a result, the metal pipe 41 is molded.

Next, with reference to FIGS. 3-6, the detailed structure of the mold 11 is demonstrated. However, in the following description, although the lower mold 11 is described, since the explanation to the same effect is established also for the upper mold 12, the description is omitted. 3 is a plan view of the mold 11 . 4 is a plan view of the mold 11 showing a state in which the first member 50 is removed. 5 is a cross-sectional view taken along line V-V shown in FIG. 3 . FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG. 5 .

However, in this embodiment, the molding apparatus 1 can mold two metal pipe materials 40 simultaneously. Therefore, as shown in FIG. 3, the mold 11 has a molding surface 47 for molding two metal pipe materials 40 arranged in parallel with each other (see also FIG. 2). However, the number of metal pipe materials 40 arranged is not limited, and may be one or three or more. The molding surface 47 has a shape extending along the longitudinal direction so as to correspond to the longitudinal direction of the metal pipe material 40 . In the following description, the longitudinal direction of the molding surface 47 is referred to as the X-axis direction, the horizontal direction orthogonal to the longitudinal direction is referred to as the Y-axis direction, and the vertical direction may be referred to as the Z-axis direction. In addition, one side in the longitudinal direction is referred to as the positive side in the X-axis direction, one side in the direction orthogonal to the longitudinal direction is referred to as the positive side in the Y-axis direction, and the upper side is referred to as the positive side in the Z-axis direction. do.

As shown in FIGS. 4 and 5 , the mold 11 is sequentially divided into three units U1, U2, and U3 from the positive side in the X-axis direction. The unit U2 is a unit corresponding to the center position of the mold 11 in the X-axis direction. The units U1 and U3 are units on both ends in the X-axis direction. Each unit U1, U2, U3 has a cooling region E1 (first region), a cooling region E2 (second region), and a cooling region E3 (third region). Cooling regions E1, E2, and E3 are surrounded by seal grooves 90 in which O-rings are disposed, respectively, in plan view. However, in the units U1, U2, and U3 and the cooling regions E1, E2, and E3, the description to the same effect is assumed unless otherwise specified. However, in the embodiment, although the mold 11 has a three-division structure by the units U1, U2, and U3, in order to achieve uniform cooling including the cooling area, the mold 11 is a single unit. can be done with

As shown in FIGS. 4 to 6 , a flow path 60 through which a cooling medium (water) flows is formed inside the mold 11 . The flow path 60 includes a plurality of cooling units 61 (slit flow paths), a supply jacket unit 62, a recovery jacket unit 63, and a supply communication unit 64 (see FIGS. 5 and 6). ) and a discharge communicating portion 66 (see FIG. 6). Further, the die holder 91 supporting the mold 11 is provided with a supply section 67 (see Figs. 5 and 6) and discharge sections 68 and 69 (see Fig. 6). However, the plurality of cooling units 61, the supply jacket unit 62, the recovery jacket unit 63, the supply communication unit 64, and the discharge communication unit 66 are the units U1, U2, and U3. ) and the cooling zones E1, E2, and E3 are provided as individual passages. On the other hand, the supply section 67 and the discharge sections 68 and 69 are provided as common passages for the units U1, U2 and U3 and the cooling regions E1, E2 and E3.

The cooling part 61 is a part that mainly functions as a part that cools the mold 11 . The cooling section 61 is formed so as to extend in the Y-axis direction. The plurality of cooling units 61 are arranged so as to line up in the X-axis direction. The supply jacket section 62 supplies a cooling medium to each cooling section 61 . The supply jacket portion 62 extends in the X-axis direction so as to be connected to an end portion of each cooling portion 61 on the negative side in the Y-axis direction. The recovery jacket section 63 is a section that recovers the cooling medium from each cooling section 61 (see FIGS. 4 and 6). The recovery jacket portion 63 extends in the X-axis direction so as to be connected to the positive end of each cooling portion 61 in the Y-axis direction.

The supply communicating portion 64 is a portion that supplies the cooling medium from the supply portion 67 to the supply jacket portion 62 by connecting the supply jacket portion 62 and the supply portion 67 . One or more supply communicating portions 64 are provided with respect to the supply jacket portion 62, and extend toward the negative side in the Z-axis direction. The discharge communicating portion 66 is a portion that discharges the cooling medium from the recovery jacket portion 63 to the discharge portion 68 by connecting the recovery jacket portion 63 and the discharge portion 68 (FIGS. 4 and 6). Reference). One or more discharge communication portions 66 are provided with respect to the recovery jacket portion 63, and extend toward the negative side in the Z-axis direction.

The supply section 67 extends in the X-axis direction in the die holder 91 (see Figs. 5 and 6). The end of the supply section 67 on the positive side in the X-axis direction is open from the die holder 91 . A nozzle (not shown) for supplying a cooling medium is inserted into the opening. The supply section 67 distributes the cooling medium to the supply communication section 64 of each unit U1, U2, U3. The discharge portion 68 extends in the X-axis direction in the die holder 91 (see Fig. 6). The discharge portion 69 extends from the end of the discharge portion 68 on the positive side in the X-axis direction to the positive side in the Y-axis direction, and is open from the die holder 91 . A nozzle (not shown) for discharging a cooling medium is inserted into the opening. The discharge portions 68 and 69 commonly discharge the cooling medium from the discharge communicating portion 66 of the units U1, U2, and U3.

The mold 11 includes a first member 50 having a molding surface 47 for molding the metal pipe material 40, and a second member supporting the first member 50 on the side opposite to the molding surface 47. Divided into (51). The first member 50 has a dividing surface 50a on the negative side in the Z-axis direction. The second member 51 has a dividing surface 51a on the positive side in the Z-axis direction. The first member 50 and the second member 51 are joined by fixing with bolts (or screws) in an overlapping state so that the split surfaces 50a and 51a contact each other. By removing the bolt (or screw), the first member 50 can be removed from the second member 51 (see Fig. 7). However, in this embodiment, the dividing surfaces 50a and 51a are constituted by a plane extending parallel to the XY plane.

The thickness of the first member 50 is smaller than that of the second member 51 . The thickness here is a dimension on the negative side in the Z-axis direction. However, the surface on the positive side of the Z-axis direction of the first member 50 is formed to be curved according to the shape of the molding surface 47 . Therefore, the thickness of the first member 50 differs depending on the place. The molding surface 47 is dug most to the negative side in the Z-axis direction at the position of the unit U2. Therefore, the division surface 50a in the unit U2 is disposed on the negative side in the Z-axis direction relative to the division surface 50a of the other units U1 and U3.

The material of the first member 50 has higher durability against molding than that of the second member 51 . Compared to the material of the second member 51, the material of the first member 50 is a hard material and a high-grade material having high wear resistance.

The second member 51 is formed with a slit 53 extending along the dividing surface 51a and opening in the dividing surface 51a. The slit 53 constitutes the cooling part 61 which is a part of the flow path 60 by joining the 1st member 50 and the 2nd member 51 together. The dividing surface 50a of the 1st member 50 is formed as a smooth surface, without forming a slit. Thus, the slit 53 defines the bottom surface 61a and the side surface 61b of the cooling part 61, and the dividing surface 50a of the first member 50 is the top surface of the cooling part 61 ( 61c) is defined (see (b) of FIG. 7). That is, by blocking the opening of the slit 53 with the first member 50, the cooling section 61, which is a flow path having a rectangular cross section, is formed.

The second member 51 is formed with a jacket groove 54 extending along the dividing surface 51a and opening in the dividing surface 51a. The jacket groove 54 constitutes the supply jacket portion 62 and the recovery jacket portion 63, which are part of the flow path 60, by joining the first member 50 and the second member 51 together. The dividing surface 50a of the 1st member 50 is formed as a smooth surface, without forming a slit. Thus, the jacket groove 54 defines the bottom surface 62a and the side surface 62b of the supply jacket portion 62, and the dividing surface 50a of the first member 50 is the supply jacket portion 62 Defines the upper surface 62c of (see Fig. 7 (a)). That is, by blocking the opening of the jacket groove 54 with the first member 50, the supply jacket portion 62, which is a flow path having a rectangular cross section, is formed. The recovery jacket portion 63 is the same.

As shown in Fig. 4, the arrangement of the slit 53 and the jacket groove 54 is the same as the arrangement of the cooling section 61, the supply jacket section 62, and the recovery jacket section 63 described above. . That is, the slits 53 extend in the Y-axis direction and are arranged in plurality in the X-axis direction. At both ends of the plurality of slits 53 in the Y-axis direction, jacket grooves 54 of the supply jacket portion 62 and jacket grooves 54 of the recovery jacket portion 63 are formed for each of the slits 53. do. However, the slit 53 and the jacket groove 54 formed in each of the units U1, U2, and U3 are disposed within the range of the seal groove portion 90 surrounding each of the cooling regions E1, E2, and E3.

The mold 11 has cooling regions E1, E2, and E3 at different positions in the X-axis direction. In the cooling regions E1 and E3, a plurality of slits 53 are arranged at the first pitch P1. In the cooling region E2, a plurality of slits 53 are arranged at a second pitch P2 shorter than the first pitch P1. Thus, the slit 53 in the cooling region E2 is formed denser than the slit 53 in the cooling regions E1 and E3.

The cross-sectional area of the disconnection of the cooling section 61 by the slit 53 is smaller than the cross-sectional areas of the supply jacket section 62 and the recovery jacket section 63 by the jacket groove 54. Specifically, as shown in FIG. 7 , the width W1 of the slit 53 is narrower than the width W2 of the jacket groove 54 . In addition, the height dimension H1 of the slit 53 is lower than the height dimension H2 of the jacket groove 54.

Next, with reference to FIGS. 5 and 8 , details of control of the cooling unit 7 by the control unit 8 will be described. However, in the following description, although the cooling of the mold 11 is explained, the cooling of the mold 12 is also explained to the same effect. As shown in FIG. 5 , the circulation mechanism 37 of the cooling unit 7 supplies a cooling medium to the supply unit 67 . The circulation mechanism 37 is connected to the inlet of the supply part 67 via a pipe 101 . Also, the circulation mechanism (37) recovers the cooling medium discharged from the discharge section (69). The circulation mechanism (37) cools the recovered cooling medium with a cooling device, and supplies the cooling medium at a predetermined temperature to the supply unit (67).

The molding apparatus 1 includes a temperature sensor 100 that detects the temperature of the mold 11 . The temperature sensor 100 transmits the detected temperature to the controller 8 . In FIG. 5 , the temperature sensor 100 is provided in a position close to the molding surface in the inside of the mold 11 . However, the temperature sensor 100 may be provided anywhere with respect to the mold 11 . For example, the temperature sensor 100 may be provided in a position different from that in FIG. 5 inside the mold 11, or may be provided on the surface of the mold 11.

The controller 8 controls the cooling capacity of the cooling unit 7 . Specifically, the controller 8 controls the cooling capacity by adjusting the flow rate of the cooling medium supplied by the circulation mechanism 37 . That is, the controller 8 decreases the flow rate of the cooling medium when the cooling capacity is reduced, and increases the flow rate of the cooling medium when the cooling capacity is increased. However, the controller 8 may adjust the cooling capacity by adjusting not only the water quantity but also the temperature of the cooling medium. However, the flow rate is easier to adjust than the temperature.

Here, with reference to FIG. 8, how the temperature of the mold 11 changes when the molding apparatus 1 performs repeated molding to manufacture a large number of metal pipes will be described. 8(a) and (b) are graphs showing the relationship between time and temperature change of the mold 11. The horizontal axis of the coordinates in Fig. 8 (a) and (b) represents the time from the start of molding. Solid line graphs TG1 and TG2 are graphs showing the temperature change of the mold 11. The vertical axis of the coordinates (vertical axis on the left side of the paper) represents the temperature of the mold 11 for the graphs TG1 and TG2. However, the location for measuring the temperature of the mold 11 may be set to any location, and may be a molding surface, the inside of the mold, or anywhere. Graphs FG1 and FG2 with two-dot chain lines are graphs showing the flow rate of the cooling medium. The vertical axis of the coordinates (vertical axis on the right side of the page) represents the flow rate of the cooling medium for the graphs FG1 and FG2.

As shown in FIG. 8(a), when the molding apparatus 1 performs the first molding, the heated metal pipe material 40 contacts the mold 11. At this time, the heat possessed by the metal pipe material 40 is input to the mold 11. Therefore, the temperature of the mold 11 rises (refer to part "A" in the figure). However, the lowest point of the temperature at the start of the first molding is referred to as "P1a". When the quenching of the metal pipe material 40 is completed and the metal pipe is removed from the mold 11, cooling by the cooling unit 7 is performed in a state in which there is no heat input to the mold 11. Accordingly, the temperature of the mold 11 is lowered (refer to part "B" in the figure). The maximum point of the temperature in the first molding is referred to as "P1b". Next, in the previous stage where the temperature of the mold 11 returns to the temperature at the start of molding, the molding apparatus 1 performs the second molding. Thereby, the temperature of the mold 11 rises again (refer to the part "C" in the figure). The lowest point of the temperature at the start of the second molding is referred to as "P2a". The maximum point by the second molding is referred to as "P2b". At this time, the temperature of the minimum point P2a in the second molding is higher than the temperature of the minimum point P1a in the first molding. Further, the temperature of the maximum point P2b in the second molding is higher than the maximum point P1b in the first molding. In this way, between the start of molding and the predetermined number of moldings, the temperatures of the minimum and maximum points gradually increase each time molding is repeated.

When molding is repeated a predetermined number of times or more, the temperature rise of the mold 11 becomes saturated. When this state is reached, the temperature of the minimum point Pma and the maximum point Pmb in a given number of moldings is unchanged from the temperature of the minimum point Pna and maximum point Pnb in the previous molding. After that, molding is repeatedly performed in a state where the temperature of the minimum point and the temperature of the maximum point are constant. Such a state may be referred to as a "stable state" in the following description.

A graph La passing through the minimum point in each shaping and a graph Lb passing through the maximum point in each shaping are set. Since the graph FG1 shows the temperature change as described above, the graphs La and Lb curve upward toward the temperature in a stable state for a predetermined period after the start of molding, and become a straight line extending horizontally when the graph is in a stable state. It has the same shape as an asymptote.

On the other hand, the control unit 8 controls the cooling unit 7 so as to suppress the decrease in hardenability of the metal pipe material 40 due to heat accumulation in the mold 11 due to repeated molding. For example, in order to perform good quenching, it is preferable that the temperature of the mold 11 is set below the temperature T1. The control part 8 controls the cooling part 7 so that the temperature of the mold 11 in a stable state may become below temperature T1. That is, the controller 8 keeps the flow rate of the cooling medium constant at a high value so that the temperature of the mold 11 in a stable state is not higher than the temperature T1 because the cooling capacity is excessively low (see graph FG1). . The controller 8 controls so that at least the temperature of the minimum point in the saturation state is equal to or less than the temperature T1. However, the temperature T1 is a value appropriately set depending on the material or size of the mold 11 or the metal pipe material 40. For example, when setting the temperature T1, the durability of the mold 11 is also taken into consideration, and when the durability is low, the temperature T1 may be suppressed low. For example, if the temperature of the mold 11 is excessively high, there is a risk that the mold strength is reduced by tempering or the like and wear is accelerated, but by setting the temperature T1 in consideration of the durability of the mold 11, same risk can be reduced.

Further, the controller 8 controls the cooling unit 7 so that the temperature of the mold 11 falls within a predetermined range. As described above, the graph TG1 shown in Fig. 8(a) falls within the range of the graph La composed of constant local minimum values and the graph La composed of constant local maximum values in a stable state. However, even in a stable state, there may be slight fluctuations in the maximum value and minimum value in molding at each time. In this case, the graphs La and Lb have a shape distorted from a straight line as shown in Fig. 8(a). However, even in this case, it is preferable that the variation of the maximum value and the minimum value fall within a predetermined error range within a range in which the stability of the hardenability of the metal pipe is not impaired.

The controller 8 may increase the cooling capacity of the cooling unit 7 as the number of moldings of the mold 11 increases. Further, the controller 8 may increase the cooling capacity of the cooling unit 7 as the molding time of the mold 11 increases. For example, the controller 8 may perform control such that the flow rate of the cooling medium draws a graph FG2 shown in FIG. 8(b). In this case, the control unit 8 suppresses the flow rate of the cooling medium to a low level at the start of molding and gradually increases it with the lapse of time. In this case, the controller 8 increases the flow rate of the cooling medium as the number of times of molding increases and as the molding time increases. However, the "molding time" here is not the time required for one molding (the time for one mountain in graph TG2), but the total time of each molding in the case of performing a plurality of moldings. Then, the control unit 8 controls the flow rate of the cooling medium to be constant when it is in a stable state.

In the control method of FIG. 8(b), the control unit 8 intentionally suppresses the cooling capacity of the cooling unit 7 at the molding start stage. In this way, the control unit 8 makes the temperature change of the mold 11 quickly reach a stable state. Specifically, in the molding start stage, the temperature rise of graph TG2 is greater than that of graph TG1. Further, the time for which the graph TG2 is in a stable state is "t1", but the temperature of the graph TG1 is still continuing to rise at the stage of "t1". Then, the graph TG1 is in a stable state at the timing when a predetermined time has elapsed from "t1". That is, in the control method of FIG. 8(b), the mold 11 enables molding in a stable state at an early stage, and the quality of the molded product can be stabilized at an early stage.

The controller 8 may adjust the cooling capacity of the cooling unit 7 based on the detection result of the temperature sensor 100 . For example, in the control of FIG. 8(b), the control unit 8 may detect that a stable state has been achieved from the detection result of the temperature sensor 100. In this way, the controller 8 can make the flow rate of the cooling medium constant at an appropriate timing. In addition, when the temperature of the mold 11 is lowered from the temperature in a stable state due to the temporary suspension of repetition of molding, the control unit 8 may grasp the temperature drop based on the detection result of the temperature sensor 100. do. In this case, the controller 8 may increase the temperature of the mold 11 so as to be in a stable state by reducing the cooling medium.

Next, actions and effects of the molding apparatus 1 according to the present embodiment will be described.

The molding apparatus 1 according to the present embodiment has molds 11 and 12 that perform quench molding by contacting a metal material. When the molds 11 and 12 come into contact with each other, the temperature of the molds 11 and 12 rises. In contrast, the molds 11 and 12 are cooled by the cooling unit 7, so that the molds 11 and 12 can be hardened and formed. In addition, the cooling unit 7 suppresses a decrease in hardenability of the metal material due to heat accumulation in the molds 11 and 12 due to repeated molding. Therefore, even if the molds 11 and 12 repeatedly receive heat input from the metal material by repeating molding, the molds 11 and 12 can perform repeated hardening and molding without deteriorating hardenability. From the above, the molding apparatus 1 can improve the stability of the quality of molded products in the case of repeated molding.

The cooling unit 7 may converge the temperature of the molds 11 and 12 within a predetermined range. In this case, the cooling unit 7 can make the temperature change pattern of the molds 11 and 12 close to a constant during molding. Therefore, the molding apparatus 1 can improve the stability of the quality of molded products. That is, the pattern of temperature change of the mold 11 in the first molding in Fig. 8 (a) and the pattern of temperature change of the mold 11 in the fifth time are different from each other. Therefore, a difference occurs in hardenability between the metal pipe formed by the first forming and the metal pipe formed by the fifth forming. In contrast, in the case of molding in a stable state, the molds 11 and 12 can be molded with a constant temperature change pattern regardless of the number of times. This stabilizes the quality of molded products.

The cooling unit 7 may increase the cooling capacity as the number of molding of the molds 11 and 12 increases. As the number of molding of the molds 11 and 12 increases, heat is easily accumulated in the molds 11 and 12 . Therefore, the cooling unit 7 can suppress heat accumulation in the molds 11 and 12 by increasing the cooling capacity as the number of molding of the molds 11 and 12 increases.

The cooling capacity of the cooling unit 7 may be increased as the molding time of the molds 11 and 12 increases. As the molding time of the molds 11 and 12 increases, heat is easily accumulated in the molds 11 and 12 . Therefore, the cooling unit 7 can suppress accumulation of heat in the molds 11 and 12 by increasing the cooling capacity as the molding time of the molds 11 and 12 increases.

The molding apparatus 1 includes a temperature sensor 100 that detects the temperature of the molds 11 and 12, and the cooling unit 7 adjusts the cooling capacity based on the detection result of the temperature sensor 100. You can do it. In this case, the cooling unit 7 can bring the molds 11 and 12 to an appropriate temperature according to the temperature of the molds 11 and 12 .

The molding method according to the present embodiment is a molding method for molding a heated metal material, and includes a molding step of performing quench molding by bringing the metal material into contact with a mold, and a cooling step of cooling the mold. In the cooling step, the molding process is repeated. The decrease in hardenability of the metal material due to the accumulation of heat in the mold due to molding may be suppressed.

According to this molding method, the same effects and effects as those of the molding apparatus 1 described above can be obtained.

This invention is not limited to the above-mentioned embodiment.

The pattern of the passage of the cooling medium formed in the mold is not limited to the above-described embodiment, and may be appropriately changed as long as the pattern can favorably cool the mold.

The control mode of the cooling capacity by the control unit is not limited to that shown in the above-described embodiment. For example, a control pattern as shown in Fig. 9 may be employed. However, in FIG. 9, only the graph La showing the change mode of the local minimum value and the graph Lb showing the change mode of the maximum value are shown, and the graph of the temperature change is omitted. The graph of temperature change has a shape like drawing a wave within the range of the graphs La and Lb.

In (a) of Fig. 9, the controller 8 adjusts the cooling capacity to be extremely high. The flow rate of graph FG3 is larger than that of graph TG1 shown in Fig. 8(a). In this case, the amount of heat removed from the molds 11 and 12 by the cooling unit 7 during one molding is greater than the amount of heat input from the metal material to the molds 11 and 12. In the control pattern of Fig. 8, the molds 11 and 12 are in a stable state at high temperatures, but in the control pattern in Fig. 9, they are in a stable state at low temperatures.

In (b) of FIG. 9 , the control unit 8 adjusts the cooling capacity so that the temperature of the molds 11 and 12 is allowed to rise, and when the temperature rises to a predetermined temperature, the temperature is lowered. As shown in graph FG4, in the molding start step, the control unit 8 suppresses the flow rate of the cooling medium to a low value, thereby allowing the temperature of the molds 11 and 12 to rise to a certain extent. The controller 8, based on the detection result of the temperature sensor 100, determines that the temperature of the molds 11 and 12 has reached a predetermined temperature, temporarily increases the flow rate of the cooling medium. Thus, the control unit 8 lowers the temperature of the molds 11 and 12 by increasing the amount of heat generated by the cooling unit 7 more than the amount of heat input to the molds 11 and 12 . The control unit 8, based on the detection result of the temperature sensor 100, returns the flow rate of the cooling medium when recognizing that the temperatures of the molds 11 and 12 have returned to about the initial stage. Here, the controller 8 sets the temperature range W of the molds 11 and 12 to such a degree that the quality of the molded article does not change excessively. In this way, the controller 8 can suppress irregularities in the quality of molded products by suppressing the width of the fluctuations while permitting fluctuations in the patterns of temperature changes of the molds 11 and 12 .

As described above, in the cooling unit 7, the amount of heat extracted from the molds 11 and 12 is greater than the amount of heat input from the metal material to the molds 11 and 12. In this case, the cooling unit 7 can suppress an increase in the temperature of the molds 11 and 12 or reduce the increased temperature of the molds 11 and 12 . In this way, in the case of repeated molding, it is possible to suppress a change in hardenability caused by an excessive increase in the temperature of the molds 11 and 12 . From the above, the molding apparatus can improve the stability of the quality of the molded article in the case of repeated molding.

The molding method according to the modified example is a molding method for molding a heated metal material, and includes a molding step of performing quench molding by bringing the metal material into contact with a mold, and a cooling step of cooling the mold. In the cooling step, the mold is removed from the mold. The amount of heat taken away is made larger than the amount of heat input from the metal material to the mold.

According to this molding method, it is possible to obtain the same effect and effect as the molding apparatus according to the modified example described above.

Moreover, you may employ|adopt the mold 110 as shown in FIG. The mold 110 shown in FIG. 10 includes a lower mold 111, an upper mold 112, and an insert mold 113. The insert mold 113 is connected to the upper mold 112 via a damper 135 . The lower mold 111, the upper mold 112, and the insert mold 113 have passages 131, 132, and 133 through which a cooling medium flows. The insert mold 113 has a protruding portion 113a for forming a complex shape. According to such a mold 110, as shown in FIG. 10(a), when the upper mold 112 is lowered and the mold is closed, first, the insert mold 113 is in a state of being close to the metal pipe material 300 . Thus, when the high-pressure fluid is supplied to the metal pipe material 300, a shape corresponding to the insert mold 113 is first molded. Then, when the upper mold 112 is lowered, as shown in FIG. .

As described above, in the case of molding a complex part having a concavo-convex shape, it is preferable to start molding at a temperature as high as possible. Therefore, by using the insert mold 113 as described above, the mold contact portion in the concave-convex shape can be suppressed to a necessary minimum. Therefore, expansion molding can be performed before the temperature of the metal pipe material 300 decreases. Here, in the insert mold structure as described above, it is considered that there is almost no heat transfer in the sliding part between the upper mold 112 and the insert mold 113. Therefore, the upper mold 112 and the insert mold 113 need to be individually cooled independently of each other. At this time, if the mold temperatures are different from each other, the molded product 301 becomes a factor having internal distortion, which affects the molding precision. Therefore, the cooling medium flowing through the passages 131, 132, and 133 is controlled so that the mold temperature difference between the lower mold 111, the upper mold 112, and the insert mold 113 does not occur as much as possible, thereby adjusting the mold temperature. It becomes necessary to do

1 molding device
7 cooling section
8 Controls
11, 12 mold
40, 300 Metal pipe material (metal material)
100 temperature sensor
111 lower mold (mould)
112 upper mold (mould)
113 Insert Mold (Mold)
131, 132, 133 euros (cooling section)

Claims (8)

As a molding device for molding a heated metal material,
A mold that performs quench molding by contacting the metal material;
A cooling unit for cooling the mold is provided;
The molding apparatus according to claim 1, wherein the cooling unit suppresses a decrease in hardenability of the metal material due to heat accumulation in the mold due to repeated molding. According to claim 1,
The cooling unit converges the temperature of the mold within a predetermined range, the molding apparatus. According to claim 1 or 2,
The cooling unit increases the cooling capacity as the number of times of molding of the mold increases. According to any one of claims 1 to 3,
The cooling unit increases the cooling capacity as the molding time of the mold increases. According to any one of claims 1 to 4,
A temperature sensor for detecting the temperature of the mold,
The cooling unit adjusts the cooling capacity based on the detection result of the temperature sensor. As a molding device for molding a heated metal material,
A mold that performs quench molding by contacting the metal material;
A cooling unit for cooling the mold is provided;
The molding apparatus of claim 1 , wherein the cooling unit makes the amount of heat taken from the mold larger than the amount of heat input from the metal material to the mold. As a molding method for molding a heated metal material,
A molding step of performing quench molding by bringing the metal material into contact with the mold;
A cooling step for cooling the mold,
In the cooling step, a decrease in hardenability of the metal material due to heat accumulation in the mold due to repeated molding is suppressed. As a molding method for molding a heated metal material,
A molding step of performing quench molding by bringing the metal material into contact with a mold;
A cooling step for cooling the mold,
In the cooling step, the amount of heat removed from the mold is greater than the amount of heat input from the metal material to the mold.

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