Forging Dies

Abstract

To provide a casting die that can suppress temperature unevenness in the whole of the die.SOLUTION: A casting die 2 comprises: a die member; a first refrigerant passage formed in the die member; a second refrigerant passage formed, along the first refrigerant passage, in the die member; and a bulkhead member separating the first refrigerant passage from the second refrigerant passage. An inlet position of a refrigerant in the first refrigerant passage and an outflow position of a refrigerant in the second refrigerant passage oppose to each other through the bulkhead member. An outflow position of a refrigerant in the first refrigerant passage and an inflow position of a refrigerant in the second refrigerant passage oppose to each other through the bulkhead member.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a forging die. [Background technology]

[0002] In forging such as hot forging, the die becomes hot during forming, so it is desirable to cool the die. A method of passing a coolant such as cooling water through the inside of the die is known as a method of efficiently cooling the die. In relation to this technology, Patent Document 1 discloses a forging die that can efficiently cool the step portion of the forming die and more reliably extend the life of the forming die. The forging die according to Patent Document 1 includes a cylindrical die base, a cylindrical forming die, and a cylindrical die bush. A first coolant passage extending in the circumferential direction along the inner step surface is provided between the opposing surfaces of the die bush and the forming die. After flowing into the first coolant passage from the coolant introduction passage, the coolant flows through the first coolant passage in two directions, clockwise and counterclockwise, and then merges on the opposite side of the first coolant passage and is discharged to the outside from the coolant discharge passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-173151 A Summary of the Invention [Problem to be solved by the invention]

[0004] As the coolant passes through the coolant passage, it is heated by the mold in which the coolant passage is formed, and the temperature of the coolant may rise. Therefore, in the method of Patent Document 1, the coolant temperature may be low near the coolant inlet passage and high near the coolant outlet passage. Therefore, the temperature of the mold may be low near the coolant inlet passage and high near the coolant outlet passage. Therefore, there is a risk of temperature unevenness occurring throughout the mold.

[0005] The present invention provides a forging die capable of suppressing temperature unevenness throughout the die. [Means for solving the problem]

[0006] A forging die according to the present invention comprises a die member, a first refrigerant flow path formed in the die member, a second refrigerant flow path formed in the die member along the first refrigerant flow path, and a partition member separating the first refrigerant flow path and the second refrigerant flow path, wherein a refrigerant inflow position in the first refrigerant flow path and a refrigerant outflow position in the second refrigerant flow path are opposed to each other via the partition member, and a refrigerant outflow position in the first refrigerant flow path and a refrigerant inflow position in the second refrigerant flow path are opposed to each other via the partition member. By being configured as described above, the present invention makes it possible to suppress temperature unevenness throughout the mold.

[0007] Preferably, the first refrigerant flow path and the second refrigerant flow path are aligned in a height direction of the mold members. By being configured as described above, the present invention makes it possible to efficiently cool the mold members.

[0008] Preferably, the first refrigerant flow path and the second refrigerant flow path are aligned in a radial direction of the mold member. By being configured as described above, the present invention can increase the strength of the forging die while suppressing the occurrence of temperature unevenness. Effect of the Invention

[0009] According to the present invention, a forging die capable of suppressing temperature unevenness throughout the die can be provided. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing a forging device according to a first embodiment. [Diagram 2] FIG. 1 is a vertical cross-sectional view showing a forging die according to a first embodiment. [Diagram 3] FIG. 1 is a vertical cross-sectional view showing a forging die according to a first embodiment. [Figure 4] 4 is a plan cross-sectional view of an upper refrigerant flow path according to the first embodiment, as viewed from above. FIG. [Diagram 5] 4 is a plan cross-sectional view of a lower refrigerant flow path according to the first embodiment, as viewed from above. FIG. [Figure 6] FIG. 4 is a vertical cross-sectional view showing a forging die according to a comparative example. [Figure 7] 10 is a plan cross-sectional view of a refrigerant flow path according to a comparative example, as viewed from above. FIG. [Figure 8] FIG. 11 is a diagram for explaining an experiment comparing the temperature at each position of the lower die according to the first embodiment with the temperature at each position of the lower die according to the comparative example. [Figure 9] FIG. 11 is a diagram for explaining an experiment comparing the temperature at each position of the lower die according to the first embodiment with the temperature at each position of the lower die according to the comparative example. [Figure 10] FIG. 11 is a diagram for explaining an experiment comparing the temperature at each position of the lower die according to the first embodiment with the temperature at each position of the lower die according to the comparative example. [Figure 11] FIG. 11 is a vertical cross-sectional view showing a forging die according to a second embodiment. [Figure 12] FIG. 11 is a plan cross-sectional view of a refrigerant flow path according to a second embodiment, as viewed from above. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, the following description and drawings are appropriately simplified for clarity of explanation.

[0012] (Embodiment 1) FIG. 1 is a diagram showing a forging device 1 according to a first embodiment. The forging device 1 manufactures a product (for example, a gear part, etc.) by performing, for example, hot forging. The forging device 1 has a forging die 2 for shaping a workpiece by forging. The forging die 2 has an upper die 4 (upper punch) and a lower die 10. The forging device 1 presses the workpiece by relatively approaching the upper die 4 and the lower die 10 in a state in which the workpiece (not shown) is disposed between the upper die 4 and the lower die 10. As a result, the workpiece is processed into a shape corresponding to the shapes of the upper die 4 and the lower die 10. In this way, the forging device 1 processes the workpiece by forging to manufacture a product. The lower die 10 is formed into a substantially cylindrical shape as a whole. The upper die 4 is formed into a substantially columnar shape as a whole. The upper die 4 and the lower die 10 are die members in the forging die 2.

[0013] 1, the direction indicated by the arrow H (vertical direction in FIG. 1) corresponds to the height direction of the forging die 2 (forging device 1) and corresponds to the pressing direction in which the workpiece is pressed. The direction indicated by the arrow R corresponds to the radial direction of the forging die 2 and corresponds to the direction moving away from the center P of the forging die 2 (lower die 10 and upper die 4) to the outside or the direction moving toward the center P. The direction indicated by the arrow C corresponds to the circumferential direction and is the direction going around the center P.

[0014] 2 and 3 are vertical cross-sectional views showing the forging die 2 according to the first embodiment. FIG. 2 shows a state in which the upper die 4 and the lower die 10 are close to each other. FIG. 3 shows a schematic cross-sectional view of the forging die 2 according to the first embodiment. In FIG. 3, only the lower die 10 is shown, and the upper die 4 is omitted. The forging die 2 (forging device 1) has the lower die 10, a clamper 32, and a jig tool 34.

[0015] The lower die 10 according to the first embodiment has a lower punch 12, a lower die 20, and a holder 30. The lower punch 12, the lower die 20, and the holder 30 are die components in the forging die 2. In FIG. 3, the vertical direction indicated by the arrow H corresponds to the height direction (press direction) of the forging die 2 (forging device 1). In FIG. 3, the horizontal direction indicated by the arrow R corresponds to the radial direction perpendicular to the height direction. In FIG. 3, the direction indicated by the arrow C corresponds to the circumferential direction around the center P of the lower die 10 (forging die 2). These directions are the same in the following figures (and in other embodiments).

[0016] The lower punch 12 forms the bottom surface of the lower die 10. The lower die 20 forms the side surface of the lower die 10. The lower die 20 is formed in an approximately cylindrical shape. The holder 30 holds the lower die 20 from the outside. Specifically, the lower die 20 is fitted into the holder 30 by press fitting, shrink fitting, cold fitting, or the like. This allows the lower die 20 and the holder 30 to be combined into one piece. Also, as shown in FIG. 3, the lower die 10, in which the lower die 20 and the holder 30 are integrated, is fixed to a jig 34 by a clamper 32. The jig 34 has the role of receiving pressure from the lower die 10 during pressing.

[0017] The lower surface 4a of the upper die 4, the upper surface 12a of the lower punch 12, and the inner surface 20a of the lower die 20 are formed with shapes corresponding to the outer shape of the product. For example, if the product is a gear part such as a counter drive gear, the inner surface 20a of the lower die 20 is formed with a gear shape for forming the gear of the gear part. By pressing the workpiece in the height direction in the gap G between the upper die 4 and the lower die 10, the workpiece is formed into a shape corresponding to the shape of the gap G (the shape of the outer surface of the upper die 4, and the shapes of the upper surface 12a and the inner surface 20a of the lower die 10). These are the same in the other embodiments.

[0018] Here, in a forging process such as hot forging, the forging die 2 becomes hot. In particular, the inner surface 20a of the lower die 20 becomes hot. Therefore, in the first embodiment, a refrigerant flow path 22 for passing a refrigerant is formed near the inner surface 20a of the lower die 10 (lower die 20). That is, the forging die 2 has the refrigerant flow path 22. The refrigerant flows through the refrigerant flow path 22. This cools the lower die 10 (particularly the inner surface 20a). The refrigerant can be appropriately selected from cooling media such as cooling water or water-soluble alcohol (the same applies to the other embodiments).

[0019] The coolant flow passage 22 according to the first embodiment is formed in the lower die 20 (lower mold 10) so as to go around once in the circumferential direction along the inner surface 20a. For example, the coolant flow passage 22 may be formed in a groove shape on the outer side (holder 30 side) of the lower die 20. The coolant flow passage 22 may be formed by combining the lower die 20 and the holder 30 together as described above.

[0020] Here, the refrigerant flow path 22 according to the first embodiment has an upper refrigerant flow path 24 and a lower refrigerant flow path 26. That is, the forging die 2 according to the first embodiment has an upper refrigerant flow path 24 and a lower refrigerant flow path 26. The upper refrigerant flow path 24 and the lower refrigerant flow path 26 each correspond to a "first refrigerant flow path" or a "second refrigerant flow path". When the upper refrigerant flow path 24 corresponds to the "first refrigerant flow path", the lower refrigerant flow path 26 corresponds to the "second refrigerant flow path". On the other hand, when the upper refrigerant flow path 24 corresponds to the "second refrigerant flow path", the lower refrigerant flow path 26 corresponds to the "first refrigerant flow path".

[0021] A partition member 28 is provided between the upper refrigerant flow path 24 and the lower refrigerant flow path 26. That is, the forging die 2 has the partition member 28. The partition member 28 is formed to complete one revolution in the circumferential direction along the refrigerant flow path 22 (the upper refrigerant flow path 24 and the lower refrigerant flow path 26). The partition member 28 separates the upper refrigerant flow path 24 from the lower refrigerant flow path 26. The upper refrigerant flow path 24 is formed above the partition member 28. Meanwhile, the lower refrigerant flow path 26 is formed below the partition member 28. Therefore, the upper refrigerant flow path 24 and the lower refrigerant flow path 26 are formed to be aligned with each other in the height direction (the direction of the arrow H).

[0022] FIG. 4 is a plan cross-sectional view of the upper refrigerant flow path 24 according to the first embodiment as viewed from above. FIG. 5 is a plan cross-sectional view of the lower refrigerant flow path 26 according to the first embodiment as viewed from above. FIG. 4 shows a cross section taken along line IV-IV in FIG. 3. FIG. 5 shows a cross section taken along line VV in FIG. 3. In FIG. 4 and FIG. 5, the "0° phase" corresponds to the front side of the lower mold 10 shown in FIG. 3. In FIG. 4 and FIG. 5, the "90° phase" corresponds to the right side of the lower mold 10 shown in FIG. 3. In FIG. 4 and FIG. 5, the "180° phase" corresponds to the rear side of the lower mold 10 shown in FIG. 3. In FIG. 4 and FIG. 5, the "270° phase" corresponds to the left side of the lower mold 10 shown in FIG. 3.

[0023] As shown in FIG. 4, the upper refrigerant flow path 24 is formed in the lower die 10 along the circumferential direction (direction indicated by arrow C). A partition 24c is provided at a position corresponding to the 90° phase of the upper refrigerant flow path 24. The partition 24c blocks the circumferential flow of the refrigerant in the upper refrigerant flow path 24. The upper refrigerant flow path 24 has a refrigerant inlet 24a at a position on the 180° phase side (refrigerant inflow position) near the partition 24c. Meanwhile, the upper refrigerant flow path 24 has a refrigerant outlet 24b at a position on the 0° phase side (refrigerant outflow position) near the partition 24c. The refrigerant inlet 24a and the refrigerant outlet 24b can be formed, for example, by drilling holes in the holder 30 in the radial direction (direction of arrow R) at positions corresponding to the upper refrigerant flow path 24. The refrigerant flows in from the refrigerant inlet 24a and flows out from the refrigerant outlet 24b, so that the refrigerant flows around the upper refrigerant flow passage 24 in a counterclockwise direction as indicated by an arrow A.

[0024] 5, the lower refrigerant flow path 26 is formed in the lower die 10 along the circumferential direction (direction indicated by arrow C). A partition 26c is provided at a position corresponding to the 90° phase of the lower refrigerant flow path 26. The partition 26c blocks the circumferential flow of the refrigerant in the lower refrigerant flow path 26. A refrigerant inlet 26a is provided at a position (refrigerant inflow position) on the 0° phase side near the partition 26c in the lower refrigerant flow path 26. Meanwhile, a refrigerant outlet 26b is provided at a position (refrigerant outflow position) on the 180° phase side near the partition 26c in the lower refrigerant flow path 26. The refrigerant inlet 26a and the refrigerant outlet 26b can be formed, for example, by drilling holes in the radial direction (direction of arrow R) at positions corresponding to the lower refrigerant flow path 26 of the holder 30. The refrigerant flows in through the refrigerant inlet 26a and flows out through the refrigerant outlet 26b, so that the refrigerant flows around the lower refrigerant flow path 26 in a clockwise direction as indicated by an arrow B.

[0025] Here, the inflow position of the refrigerant in the upper refrigerant flow passage 24 (position of the refrigerant inlet 24a) and the outflow position of the refrigerant in the lower refrigerant flow passage 26 (position of the refrigerant outlet 26b) are opposed to each other via the partition member 28. Similarly, the outflow position of the refrigerant in the upper refrigerant flow passage 24 (position of the refrigerant outlet 24b) and the inflow position of the refrigerant in the lower refrigerant flow passage 26 (position of the refrigerant inlet 26a) are opposed to each other via the partition member 28. Also, the direction in which the refrigerant flows in the upper refrigerant flow passage 24 is opposite to the direction in which the refrigerant flows in the lower refrigerant flow passage 26. With such a configuration, the forging die 2 according to the first embodiment can suppress temperature unevenness in the lower die 10 (forging die 2) during forging, as described later. In particular, temperature unevenness in the circumferential direction of the lower die 10 can be suppressed. In other words, temperature variation at the positions in each phase of the lower die 10 can be suppressed.

[0026] (Comparative Example) FIG. 6 is a vertical cross-sectional view showing a forging die 80 according to a comparative example. FIG. 6 shows a schematic cross-sectional view of the forging die 80 according to the comparative example. FIG. 6 corresponds to FIG. 3 showing the forging die 2 according to the first embodiment. The forging die 80 according to the comparative example can be provided in the forging device 1 shown in FIG. The forging die 80 according to the comparative example has a lower die 90, a clamper 32, and a jig tool 34. Although not shown in the figure, the forging die 80 also has an upper die 4, similar to the forging die 2 according to the first embodiment.

[0027] The lower die 90 has a lower punch 12, a lower die 92, and a holder 30. The lower die 92 is formed in a substantially cylindrical shape. As in the first embodiment, the holder 30 holds the lower die 92 from the outside. A refrigerant flow path 94 for passing a refrigerant is formed near an inner side surface 92a of the lower die 90 (lower die 92). The refrigerant flows through the refrigerant flow path 94. This cools the inner side surface 92a. Here, the lower die 10 according to the first embodiment has two refrigerant flow paths (the upper refrigerant flow path 24 and the lower refrigerant flow path 26) in the height direction, but the lower die 90 according to the comparative example has only one refrigerant flow path 94. That is, no partition member is provided in the refrigerant flow path 94.

[0028] FIG. 7 is a plan cross-sectional view of the refrigerant flow passage 94 according to the comparative example, as viewed from above. FIG. 7 shows a cross section taken along line VII-VII in FIG. 6. As shown in FIG. 7, the refrigerant flow passage 94 is formed in the lower mold 90 along the circumferential direction (the direction indicated by the arrow C). A partition 94c is provided at a position corresponding to the 90° phase of the refrigerant flow passage 94. The partition 94c blocks the circumferential flow of the refrigerant in the refrigerant flow passage 94. A refrigerant inlet 94a is provided at a position on the 180° phase side near the partition 94c in the refrigerant flow passage 94. Meanwhile, a refrigerant outlet 94b is provided at a position on the 0° phase side near the partition 94c in the refrigerant flow passage 94. The refrigerant flows in from the refrigerant inlet 94a and flows out from the refrigerant outlet 94b, so that the refrigerant flows around the refrigerant flow passage 94 in a counterclockwise direction as indicated by the arrow A.

[0029] Here, the temperature of the coolant is low at a position (around the area indicated by the arrow D) close to the coolant inlet 94a in the coolant flow passage 94 because the cooled coolant has just flowed into the coolant flow passage 94. Therefore, the area indicated by the arrow D in the lower die 92 of the lower mold 90 is well cooled by the coolant, so the temperature of the area is low. On the other hand, as the coolant flows through the coolant flow passage 94, it is warmed by the high-temperature lower mold 90 (lower die 92). Therefore, at a position (around the area indicated by the arrow E) close to the coolant outlet 94b in the lower die 92 of the lower mold 90, the temperature of the coolant is higher than that of the area indicated by the arrow D. Therefore, the area indicated by the arrow E in the lower die 92 of the lower mold 90 is not cooled much by the coolant, so the temperature of the area may remain higher than that of the area indicated by the arrow D. Therefore, a temperature difference occurs between the area indicated by the arrow D and the area indicated by the arrow E in the lower die 92. That is, a temperature difference occurs between a position on the 180° phase side and a position on the 0° phase side with respect to the 90° phase position of the lower die 92.

[0030] Thus, in the comparative example, there is a risk of unevenness in the temperature of the inner surface 92a of the lower die 92. This may cause variations in the dimensions of the lower die 92. In other words, there is a risk of thermal stress occurring due to differences in thermal expansion depending on the position of the lower die 92. This may cause distortion of the lower die 92 (lower mold 90). Such distortion of the lower die 92 may cause poor quality of products manufactured by forging.

[0031] On the other hand, in the first embodiment, the position of the refrigerant inlet 24a in the upper refrigerant flow passage 24 and the position of the refrigerant outlet 26b in the lower refrigerant flow passage 26 are opposed to each other through the partition member 28. Similarly, the position of the refrigerant outlet 24b in the upper refrigerant flow passage 24 and the position of the refrigerant inlet 26a in the lower refrigerant flow passage 26 are opposed to each other through the partition member 28. This allows the position in the lower die 20 near the refrigerant outlet 24b of the upper refrigerant flow passage 24 to be cooled by the relatively low-temperature refrigerant that has just flowed in from the refrigerant inlet 26a in the lower refrigerant flow passage 26. Similarly, the position in the lower die 20 near the refrigerant outlet 26b of the lower refrigerant flow passage 26 can be cooled by the relatively low-temperature refrigerant that has just flowed in from the refrigerant inlet 24a in the upper refrigerant flow passage 24. Therefore, it is possible to suppress the occurrence of a temperature difference between the position on the 180° phase side and the position on the 0° phase side in the vicinity of the 90° phase position of the lower die 20.

[0032] In addition, the direction in which the refrigerant flows in the upper refrigerant flow passage 24 is opposite to the direction in which the refrigerant flows in the lower refrigerant flow passage 26. This allows cooling to be performed so that temperature variations are suppressed at each position (phase) in the circumferential direction of the lower die 20 other than the vicinity of the refrigerant inlet / outlet (90° phase). That is, the position (phase) closer to the outlet side in the circumferential direction of one refrigerant flow passage (upper refrigerant flow passage 24 or lower refrigerant flow passage 26) faces the position (phase) closer to the inlet side in the circumferential direction of the other refrigerant flow passage (lower refrigerant flow passage 26 or upper refrigerant flow passage 24). As described above, the temperature of the refrigerant can usually increase as it passes through a refrigerant flow passage due to heating by the lower die 20 in which the refrigerant flow passage is formed. Therefore, the position (phase) through which a higher temperature refrigerant passes in one refrigerant flow passage can be the position (phase) through which a lower temperature refrigerant passes in the other refrigerant flow passage. Specifically, in the 0° phase, the temperature of the refrigerant flowing through the upper refrigerant flow passage 24 may be slightly higher than that near the outlet, and the temperature of the refrigerant flowing through the lower refrigerant flow passage 26 may be slightly lower than that near the inlet. In addition, in the 180° phase, the temperature of the refrigerant flowing through the upper refrigerant flow passage 24 may be slightly lower than that near the inlet, and the temperature of the refrigerant flowing through the lower refrigerant flow passage 26 may be slightly higher than that near the outlet. In addition, in the 270° phase, the temperature of the refrigerant flowing through the upper refrigerant flow passage 24 may be approximately the same as that of the refrigerant flowing through the lower refrigerant flow passage 26. Therefore, the average difference between the temperature of the refrigerant flowing through the upper refrigerant flow passage 24 and the temperature of the refrigerant flowing through the lower refrigerant flow passage 26 for each position (each phase) in the circumferential direction may be reduced. Therefore, the temperature variation at each position (each phase) in the circumferential direction of the lower die 20 is reduced.

[0033] Therefore, in the forging die 2 according to the first embodiment, it is possible to suppress the occurrence of temperature unevenness in the circumferential direction of the lower die 20. Therefore, it is possible to suppress the occurrence of variation in the dimensions of the lower die 20. Therefore, in the forging die 2 according to the first embodiment, it is possible to suppress the occurrence of quality defects in products manufactured by forging.

[0034] (Experimental Results) 8 to 10 are diagrams for explaining an experiment comparing the temperature at each position of the lower die 20 according to the first embodiment with the temperature at each position of the lower die 92 according to the comparative example. As shown in FIG. 8, for each of the lower die 20 according to the first embodiment and the lower die 92 according to the comparative example, thermocouples were installed at each circumferential position (each phase) #1 to #6 to measure the temperature at that position. Then, for the lower die 92 according to the comparative example, a refrigerant was made to flow through the refrigerant flow passage 94 as shown by the arrow F. Meanwhile, for the lower die 92 according to the first embodiment, a refrigerant was made to flow through the upper refrigerant flow passage 24 as shown by the arrow F, and a refrigerant was made to flow through the lower refrigerant flow passage 26 in the opposite direction to the direction of the arrow F.

[0035] Therefore, in the lower die 92 according to the comparative example, the measurement position #1 is closer to the refrigerant inlet 94a of the refrigerant flow path 94 than the other measurement positions, and the measurement position #6 is closer to the refrigerant outlet 94b of the refrigerant flow path 94 than the other measurement positions. Also, in the lower die 20 according to the first embodiment, the measurement position #1 is closer to the refrigerant inlet 24a of the upper refrigerant flow path 24 and closer to the refrigerant outlet 24b of the lower refrigerant flow path 26 than the other measurement positions. Meanwhile, the measurement position #6 is closer to the refrigerant outlet 24b of the upper refrigerant flow path 24 and closer to the refrigerant inlet 26a of the lower refrigerant flow path 26 than the other measurement positions.

[0036] FIG. 9 is a graph showing temperature changes at the measurement positions #1 to #6 of the lower die 92 according to the comparative example. As shown by the dashed rectangle, the temperature at each of the measurement positions #1 to #6 increases as the lower die 92 is heated by molding. Then, over time, the temperature at each of the measurement positions #1 to #6 decreases due to the refrigerant flowing through the refrigerant flow passage 94. Here, as shown by the dashed oval, the temperature decreases relatively well at the measurement positions #1 and #2, which are relatively close to the refrigerant inlet 94a. However, the temperature does not decrease much at the measurement positions #5 and #6, which are relatively far from the refrigerant inlet 94a. Therefore, it can be seen that temperature variations (temperature unevenness) occur at the measurement positions #1 to #6 in the lower die 92 according to the comparative example.

[0037] FIG. 10 is a graph showing temperature changes at the measurement positions #1 to #6 of the lower die 20 according to the first embodiment. As in the case of FIG. 9, as shown by the dashed rectangle, the temperature at each of the measurement positions #1 to #6 rises due to the lower die 20 being heated by molding. Then, over time, the temperature at each of the measurement positions #1 to #6 decreases due to the refrigerant flowing through the refrigerant flow passage 22 (the upper refrigerant flow passage 24 and the lower refrigerant flow passage 26). Then, as shown by the dashed oval, the temperature at all of the measurement positions #1 to #6 decreases satisfactorily. Thus, it can be seen that the lower die 20 according to the first embodiment suppresses the occurrence of temperature variation (temperature unevenness) at the measurement positions #1 to #6. Specifically, compared to the lower die 92 according to the comparative example, the lower die 20 according to the first embodiment reduces temperature variation by about 65%.

[0038] (Embodiment 2) Next, a description will be given of embodiment 2. Note that the forging device 1 according to embodiment 2 is substantially similar to that shown in Fig. 1, and therefore a description thereof will be omitted.

[0039] Fig. 11 is a vertical cross-sectional view showing a forging die 2 according to embodiment 2. Fig. 11 shows a schematic cross-sectional view of the forging die 2. In Fig. 11, only the lower die 10 is shown, and the upper die 4 is omitted. That is, the forging die 2 according to embodiment 2 has an upper die 4, similar to embodiment 1. The forging die 2 (forging device 1) has the lower die 10, a clamper 32, and a jig tool 34.

[0040] The lower die 10 according to the second embodiment includes a lower punch 12, a lower die 40, a holder 42, and a partition member 44. The lower die 40 is formed in a substantially cylindrical shape. The partition member 44 is provided outside the lower die 40. The partition member 44 may be formed in a cylindrical shape (ring shape). The holder 42 is provided outside the partition member 44. That is, the partition member 44 is provided between the lower die 40 and the holder 42. The holder 42 holds the lower die 40 and the partition member 44 from the outside. Specifically, the lower die 40 and the partition member 44 are fitted into the holder 42 by press fitting, shrink fitting, cold fitting, or the like. As a result, the lower die 40, the partition member 44, and the holder 42 are combined together. As shown in FIG. 11, the lower mold 10 in which the lower die 40, the partition member 44, and the holder 42 are integrated is fixed to a jig 34 by a clamper 32.

[0041] Here, in the second embodiment, in order to cool the lower die 10 (particularly the inner surface 40a of the lower die 40), a coolant flow path 52 is formed in the lower die 10, similar to the lower die 10 according to the first embodiment. That is, the forging die 2 according to the second embodiment has the coolant flow path 52. A coolant flows through the coolant flow path 52. This cools the lower die 10.

[0042] The refrigerant flow passage 52 according to the second embodiment is formed in the lower die 10 so as to go around once in the circumferential direction along the inner surface 40a. Here, the refrigerant flow passage 52 according to the second embodiment has an inner refrigerant flow passage 54 and an outer refrigerant flow passage 56. That is, the forging die 2 according to the second embodiment has an inner refrigerant flow passage 54 and an outer refrigerant flow passage 56. The inner refrigerant flow passage 54 and the outer refrigerant flow passage 56 each correspond to the "first refrigerant flow passage" or the "second refrigerant flow passage". When the inner refrigerant flow passage 54 corresponds to the "first refrigerant flow passage", the outer refrigerant flow passage 56 corresponds to the "second refrigerant flow passage". On the other hand, when the inner refrigerant flow passage 54 corresponds to the "second refrigerant flow passage", the outer refrigerant flow passage 56 corresponds to the "first refrigerant flow passage".

[0043] The inner refrigerant flow passage 54 is formed in a groove shape on the outer side (the partition member 44 side) of the lower die 40. The outer refrigerant flow passage 56 is formed in a groove shape on the inner side (the partition member 44 side) of the holder 42. As described above, the lower die 40, the partition member 44, and the holder 42 are integrally combined to form the refrigerant flow passage 52. That is, the inner refrigerant flow passage 54 is formed between the lower die 40 and the partition member 44, and the outer refrigerant flow passage 56 is formed between the holder 42 and the partition member 44.

[0044] As a result, the partition member 44 is provided between the inner refrigerant flow path 54 and the outer refrigerant flow path 56. That is, the forging die 2 has the partition member 44. The partition member 44 is formed to go around the refrigerant flow path 52 (the inner refrigerant flow path 54 and the outer refrigerant flow path 56) in the circumferential direction. The partition member 44 separates the inner refrigerant flow path 54 and the outer refrigerant flow path 56. The inner refrigerant flow path 54 is formed inside the partition member 44. On the other hand, the outer refrigerant flow path 56 is formed outside the partition member 44. Therefore, the inner refrigerant flow path 54 and the outer refrigerant flow path 56 are formed to be aligned with each other in the radial direction (the direction of the arrow R).

[0045] FIG. 12 is a plan cross-sectional view of the refrigerant flow path 52 according to the second embodiment as viewed from above. FIG. 12 shows a cross section taken along line XII-XII in FIG. 11. Accordingly, FIG. 12 is a plan cross-sectional view of the inner refrigerant flow path 54 and the outer refrigerant flow path 56 according to the second embodiment as viewed from above. Here, in FIG. 12, the "0° phase" corresponds to the front side of the lower mold 10 shown in FIG. 11. Also, in FIG. 12, the "90° phase" corresponds to the right side of the lower mold 10 shown in FIG. 11. Also, in FIG. 12, the "180° phase" corresponds to the rear side of the lower mold 10 shown in FIG. 11. Also, in FIG. 12, the "270° phase" corresponds to the left side of the lower mold 10 shown in FIG. 11.

[0046] As shown in FIG. 12, the inner refrigerant flow passage 54 is formed inside the partition member 44 of the lower mold 10 along the circumferential direction (the direction indicated by the arrow C). A partition 54c is provided at a position corresponding to the 90° phase of the inner refrigerant flow passage 54. The partition 54c blocks the circumferential flow of the refrigerant in the inner refrigerant flow passage 54. The inner refrigerant flow passage 54 has a refrigerant inlet 54a at a position on the 0° phase side (refrigerant inflow position) near the partition 54c. Meanwhile, the inner refrigerant flow passage 54 has a refrigerant outlet 54b at a position on the 180° phase side (refrigerant outflow position) near the partition 54c. The refrigerant flows in from the refrigerant inlet 54a and flows out from the refrigerant outlet 54b, so that the refrigerant flows around the inner refrigerant flow passage 54 in a clockwise direction as indicated by the arrow B. The refrigerant inlet 54a and the refrigerant outlet 54b may be formed, for example, by drilling holes in the height direction at positions corresponding to the inner refrigerant flow passage 54 of the lower die 40. For example, the refrigerant inlet 54a and the refrigerant outlet 54b may be formed by drilling holes from above on the upper surface of the lower die 40 in Fig. 11. Alternatively, the refrigerant inlet 54a and the refrigerant outlet 54b may be formed by drilling holes in the radial direction at positions corresponding to the inner refrigerant flow passage 54 of the partition member 44.

[0047] The outer refrigerant flow passage 56 is formed outside the partition member 44 of the lower mold 10 along the circumferential direction (direction indicated by arrow C). A partition portion 56c is provided at a position corresponding to the 90° phase of the outer refrigerant flow passage 56. The partition portion 56c blocks the circumferential flow of the refrigerant in the outer refrigerant flow passage 56. A refrigerant inlet 56a is provided at a position on the 180° phase side (refrigerant inflow position) near the partition portion 56c in the outer refrigerant flow passage 56. Meanwhile, a refrigerant outlet 56b is provided at a position on the 0° phase side (refrigerant outflow position) near the partition portion 56c in the outer refrigerant flow passage 56. The refrigerant flows in from the refrigerant inlet 56a and flows out from the refrigerant outlet 56b, so that the refrigerant flows around the outer refrigerant flow passage 56 in a counterclockwise direction as indicated by arrow A. The refrigerant inlet 56a and the refrigerant outlet 56b may be formed, for example, by drilling holes in the height direction at positions corresponding to the outer refrigerant flow passage 56 of the holder 42. For example, the refrigerant inlet 56a and the refrigerant outlet 56b may be formed by drilling holes from above on the upper surface of the holder 42 in FIG. 11. Alternatively, the refrigerant inlet 56a and the refrigerant outlet 56b may be formed by drilling holes in the radial direction at positions corresponding to the outer refrigerant flow passage 56 of the partition member 44. The refrigerant flowing through the outer refrigerant flow passage 56 can cool the lower die 40 via the partition member 44.

[0048] Here, the inflow position of the refrigerant in the inner refrigerant flow passage 54 (position of the refrigerant inlet 54a) and the outflow position of the refrigerant in the outer refrigerant flow passage 56 (position of the refrigerant outlet 56b) are opposed to each other via the partition member 44. Similarly, the outflow position of the refrigerant in the inner refrigerant flow passage 54 (position of the refrigerant outlet 54b) and the inflow position of the refrigerant in the outer refrigerant flow passage 56 (position of the refrigerant inlet 56a) are opposed to each other via the partition member 44. As a result, a position near the refrigerant outlet 54b in the inner refrigerant flow passage 54 of the lower mold 10 is cooled by the relatively low-temperature refrigerant that has just flowed in from the refrigerant inlet 56a in the outer refrigerant flow passage 56. Similarly, a position near the refrigerant outlet 56b in the outer refrigerant flow passage 56 of the lower mold 10 is cooled by the relatively low-temperature refrigerant that has just flowed in from the refrigerant inlet 54a in the inner refrigerant flow passage 54. Therefore, similarly to the first embodiment, it is possible to suppress the occurrence of a temperature difference between the position on the 180° phase side and the position on the 0° phase side with respect to the 90° phase position of the lower die 40 (lower mold 10). Also, the direction in which the refrigerant flows in the inner refrigerant flow passage 54 is opposite to the direction in which the refrigerant flows in the outer refrigerant flow passage 56. Therefore, similarly to the first embodiment described above, the temperature variation at each position (each phase) in the circumferential direction of the lower die 40 (lower mold 10) is reduced.

[0049] Therefore, similarly to the above-described first embodiment, the forging die 2 according to the second embodiment can suppress temperature unevenness in the circumferential direction of the lower die 40. This can suppress variation in the dimensions of the lower die 40. Therefore, the forging die 2 according to the second embodiment can suppress quality defects in products manufactured by forging.

[0050] In the second embodiment, the inner refrigerant flow passage 54 is formed in the lower die 40 and the outer refrigerant flow passage 56 is formed in the holder 42, whereas in the first embodiment, both the upper refrigerant flow passage 24 and the lower refrigerant flow passage 26 are formed in the lower die 20. Therefore, both of the two refrigerant flow passages in the first embodiment are formed close to the inner surface 20a of the lower die 20. Therefore, the forging die 2 according to the first embodiment can cool the lower die 10 (die member) more efficiently than the forging die 2 according to the second embodiment.

[0051] In addition, in the first embodiment, the lower die 10 has a two-layer structure in the radial direction, which is made up of the lower die 20 and the holder 30, whereas in the second embodiment, the lower die 10 has a three-layer structure in the radial direction, which is made up of the lower die 40, the partition member 44, and the holder 42. Therefore, the forging die 2 according to the second embodiment can have a higher strength than the forging die 2 according to the first embodiment. In other words, the forging die 2 according to the second embodiment can have an increased strength while suppressing the occurrence of temperature unevenness.

[0052] (Modification) The present invention is not limited to the above embodiment, and can be modified as appropriate without departing from the spirit of the invention. For example, the forging die 2 according to the present embodiment is not limited to one used for hot forging. The present embodiment can also be applied to a forging die for cold forging and warm forging.

[0053] In the above-described embodiment, the coolant flow path is formed in the lower die, but this is not limited thereto. The coolant flow path according to the above-described embodiment may be formed in the upper die or the lower punch. In other words, the die member for suppressing temperature unevenness is not limited to the lower die, but may be the upper die or the lower punch. In the above-described embodiment, the coolant inlet and the coolant outlet in the coolant flow path are provided at positions with a phase of 90° in the circumferential direction, but this is not limited thereto. The coolant inlet and the coolant outlet may be provided at any position in the circumferential direction.

[0054] In addition, the refrigerant flow path in the above-described embodiment is formed in a circular shape when viewed from above, but is not limited to this. The refrigerant flow path does not have to be formed in a circular shape, and can be formed appropriately according to the shape of the forging die. In addition, in the above-described embodiment, the refrigerant flow path has two flow paths (the upper refrigerant flow path 24 and the lower refrigerant flow path 26, or the inner refrigerant flow path 54 and the outer refrigerant flow path 56), but is not limited to this. The refrigerant flow path may have three or more flow paths. In this case, the flow directions of the refrigerant in the three or more flow paths may be staggered. [Explanation of symbols]

[0055] 1 Forging equipment 2 Forging dies 4 Upper mold 10 Lower mold 12 Lower punch 20 Lower Dice 20a Inner surface 22 Coolant flow path 24 Upper coolant flow path 24a Refrigerant inlet 24b Refrigerant outlet 24c Partition 26 Lower coolant passage 26a Refrigerant inlet 26b Refrigerant outlet 26c Partition 28 Partition wall member 30 Holder 40 Lower Dice 40a Inner surface 42 Holder 44 Partition wall member 52 Coolant flow path 54 Inner coolant flow passage 54a Refrigerant inlet 54b Refrigerant outlet 54c Partition 56 Outside refrigerant flow path 56a Refrigerant inlet 56b Refrigerant outlet 56c Partition

Claims

1. A mold member; A first coolant flow passage formed in the die member in a circumferential direction; a second refrigerant flow path formed in the die member in a circumferential direction along the first refrigerant flow path; a partition member separating the first refrigerant flow path and the second refrigerant flow path; having a first inflow position of the refrigerant in the first refrigerant flow path with respect to the mold member faces a second outflow position of the refrigerant in the second refrigerant flow path with respect to the mold member through the partition member, and a first outflow position of the refrigerant in the first refrigerant flow path with respect to the mold member faces a second inflow position of the refrigerant in the second refrigerant flow path with respect to the mold member through the partition member, The first refrigerant flow path is provided with a first partition portion that blocks a flow in a circumferential direction, The second refrigerant flow path is provided with a second partition portion that blocks a flow in a circumferential direction, the first inflow position is adjacent to the first outflow position via the first partition portion, and in the first refrigerant flow path, the refrigerant flows in a first direction in a circumferential direction from the first inflow position to the first outflow position, the second inflow position is adjacent to the second outflow position via the second partition portion, and in the second refrigerant flow path, the refrigerant flows in a second direction, which is opposite to the first direction, in a circumferential direction from the second inflow position to the second outflow position. Forging mold.

2. The first refrigerant flow path and the second refrigerant flow path are formed to be aligned with each other in a height direction of the mold member. The forging die according to claim 1 .

3. The first refrigerant flow path and the second refrigerant flow path are formed to be aligned with each other in a radial direction of the mold member. The forging die according to claim 1 .

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