Cooling jacket and quenching device

Abstract

To provide a cooling jacket capable of unformizing a cooling speed, and a hardening device.SOLUTION: A cooling jacket 10 comprises: a coolant feed member 20 passing through a coolant 201; and a coolant jet member 30 fed with the coolant 201 from the coolant feed member 20 and having plural holes 32 and 33 jetting the coolant 201 formed. A coolant jet face 31 facing a workpiece in the coolant jet member 30 has an upper region 35, a center region 36 and a lower region 37 arranged along a vertical direction V. The area of each jet hole 33 formed at the center region 36 is larger than the area of each jet hole 32 formed at the upper region 35 and the area of each jet hole 32 formed at the lower region 37. The coolant jet member 30 moves relatively in a horizontal direction H with respect to the workpiece 100. The closest direction W arranged with the plural jet holes 32 and 33 at the shortest intervals is tilted in both of the horizontal direction H and the vertical direction V.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] Embodiments of the present invention relate to a cooling jacket and a quenching device.

Background Art

[0002] A quenching device is used to perform a quenching process on a steel part (hereinafter referred to as a "workpiece") by heating the workpiece to a high temperature above the austenite transformation point and then rapidly cooling the workpiece. In such a quenching device, in order to perform a uniform quenching process on the workpiece, it is necessary to uniformly cool the surface of the heated workpiece where quenching is to be performed. However, if the workpiece is large or has a complex shape, uniform cooling is difficult.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of embodiments of the present invention is to provide a cooling jacket and a quenching device capable of uniformizing the cooling rate.

Means for Solving the Problems

[0005] The cooling jacket according to an embodiment of the present invention includes a coolant supply member through which a coolant flows, and a coolant injection member to which the coolant is supplied from the coolant supply member and in which a plurality of injection holes for injecting the coolant are formed. A surface of the coolant injection member facing the workpiece has an upper region, a central region, and a lower region arranged along the vertical direction. The area of each of the injection holes formed in the central region is larger than the area of each of the injection holes formed in the upper region and the area of each of the injection holes formed in the lower region. The coolant injection member moves relatively in the horizontal direction with respect to the workpiece. The densest direction in which the plurality of injection holes are arranged at the shortest intervals is inclined with respect to both the horizontal direction and the vertical direction.

[0006] The quenching device according to an embodiment of the present invention includes the cooling jacket and heating means for heating the workpiece.

Advantages of the Invention

[0007] According to an embodiment of the present invention, it is possible to realize a cooling jacket and a quenching device capable of equalizing the cooling rate.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

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Figure 4

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Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a quenching apparatus according to the present embodiment. FIG. 2 is a perspective cross-sectional view showing region A of FIG. 1. FIG. 3 is an enlarged perspective cross-sectional view showing a cooling jacket according to the present embodiment. FIG. 4 is a side view showing a coolant injection surface of the cooling jacket according to the present embodiment.

[0010] As shown in FIG. 1, in the present embodiment, the workpiece 100 to be quenched is, for example, a swivel ring. The overall shape of the workpiece 100 is substantially annular, and a plurality of tooth portions 101 are provided on the inner surface thereof. The plurality of tooth portions 101 are periodically arranged along the circumferential direction of the workpiece 100. The quenching apparatus 1 according to the present embodiment performs a quenching process on the inner surface of the workpiece 100.

[0011] In the quenching apparatus 1, a cooling jacket 10, a heating means, and a moving means 60 are provided. In the present embodiment, the cooling jacket 10 is disposed inside the workpiece 100, and the moving means 60 is disposed outside the workpiece 100. The moving means 60 is, for example, a driving roller that rotates the workpiece 100 by contacting the outer peripheral surface of the workpiece 100. The moving means 60 relatively moves the workpiece 100 with respect to the cooling jacket 10 by rotating the workpiece 100.

[0012] As shown in FIGS. 1 to 3, in the cooling jacket 10, a coolant supply member 20 and a coolant injection member 30 are provided. The shape of the coolant supply member 20 is substantially disk-shaped. A coolant flow path is formed inside the coolant supply member 20. The coolant supply member 20 is supplied with coolant from the outside, for example, through the central portion of the lower surface, and distributes this coolant to the outer peripheral surface of the coolant supply member 20.

[0013] The coolant injection member 30 is attached to the outer peripheral surface of the coolant supply member 20. The shape of the coolant injection member 30 is ring-shaped. The outer peripheral surface of the coolant injection member 30 serves as a coolant injection surface 31. The coolant injection surface 31 faces the inner peripheral surface of the workpiece 100. The central axis C of the cooling jacket 10 extends in the vertical direction V.

[0014] The heating means is disposed inside the cooling jacket 10 and is incorporated, for example, inside the coolant injection member 30. The heating means is, for example, a high-frequency induction coil. A plate-like member 21 is attached to the lower surface of the coolant supply member 20. The plate-like member 21 is disposed below the gap between the coolant injection member 30 and the workpiece 100.

[0015] By the moving means 60, the coolant injection surface 31 moves relative to the workpiece 100 in the circumferential direction of the workpiece 100. The circumferential direction of the workpiece 100 is parallel to the horizontal plane and is a kind of horizontal direction H.

[0016] As shown in FIG. 4, a plurality of injection holes 32 and 33 are respectively formed in the coolant injection surface 31 of the coolant injection member 30. The injection holes 32 and 33 are holes for injecting the coolant supplied by the coolant supply member 20 against the workpiece 100. The direction in which the injection holes 32 and 33 extend is, for example, the radial direction of the cooling jacket 10 and is the horizontal direction. The shape of the injection holes 32 and 33 is, for example, cylindrical. The diameter of the injection hole 33 is larger than the diameter of the injection hole 32. For this reason, on the coolant injection surface 31, the area of each injection hole 33 is larger than the area of each injection hole 32.

[0017] On the coolant injection surface 31, the injection holes 32 and 33 form a plurality of rows and are two-dimensionally arranged. The row 34 shown in FIG. 4 is the row in which the injection holes 32 and 33 are arranged at the shortest interval. That is, among the distances between adjacent injection holes, the distance D1 in the densest direction W in which the row 34 extends is shorter than any of the distances D2 in the horizontal direction H, the distance D3 in the vertical direction V, and the distances D4, D5, D6 in other directions. The densest direction W is inclined with respect to both the vertical direction V and the horizontal direction H. On the coolant injection surface 31, a plurality of rows 34 are formed and are arranged periodically or substantially periodically along the circumferential direction of the coolant injection member 30.

[0018] On the coolant injection surface 31, an upper region 35, a central region 36, and a lower region 37 are set along the vertical direction V. The lower region 37 is located below the upper region 35, that is, in the direction of gravity. The central region 36 is disposed between the upper region 35 and the lower region 37. Injection holes 32 are formed in the upper region 35 and the lower region 37. Injection holes 33 are formed in the central region 36. Therefore, the area of each injection hole formed in the central region 36 is larger than the area of each injection hole formed in the upper region 35 and the area of each injection hole formed in the lower region 37.

[0019] The length of the central region 36 in the vertical direction V is longer than the length of the upper region 35 in the vertical direction V and longer than the length of the lower region 37 in the vertical direction V. For example, the length of the central region 36 in the vertical direction V is longer than the sum of the lengths of the upper region 35 and the lower region 37 in the vertical direction V. In the example shown in FIG. 4, in the upper region 35, four rows of injection holes 32 are provided along the vertical direction V, in the central region 36, twelve rows of injection holes 33 are provided along the vertical direction V, and in the lower region 37, three rows of injection holes 32 are provided along the vertical direction V.

[0020] Note that in FIG. 4, the position of the workpiece 100 is also represented by a two-dot chain line. As shown in FIGS. 2 to 4, in the vertical direction V, the position of the upper edge of the coolant injection surface 31 is substantially equal to the position of the upper edge of the workpiece 100, and the position of the lower edge of the coolant injection surface 31 is substantially equal to the position of the lower edge of the workpiece 100.

[0021] Next, the operation of the quenching apparatus 1 according to the present embodiment will be described. As shown in FIG. 1, the workpiece 100 is arranged such that its inner surface faces the cooling jacket 10 and its outer surface abuts against the moving means 60. At this time, the central axis of the workpiece 100 is made to coincide with the central axis C of the cooling jacket 10.

[0022] Next, the moving means 60 rotates the workpiece 100. As a result, the coolant injection member 30 of the cooling jacket 10 moves relative to the workpiece 100 in the horizontal direction H.

[0023] Next, the heating means of the coolant injection member 30 heats the workpiece 100. At this time, when the workpiece 100 is made of steel, it is heated to a temperature equal to or higher than the austenite transformation point. Then, the heating means is stopped.

[0024] Next, coolant is supplied into the coolant supply member 20. The coolant is, for example, an aqueous polymer solution or water. The coolant flows through the coolant supply member 20 and reaches the coolant injection member 30, and is injected from the injection holes 32 and 33. The injected coolant contacts the inner surface of the workpiece 100. As a result, the workpiece 100 is cooled. As a result, a quenching process is performed on the inner surface of the workpiece 100.

[0025] Hereinafter, the cooling process will be described in more detail. FIGS. 5(a) to (c) are diagrams schematically showing the operation of the cooling jacket according to the present embodiment. FIGS. 5(a) to (c) show the initial stage of cooling. Also, in FIGS. 5(a) to (c), the injection of the coolant is represented by arrows, and the thick arrows indicate that the injection amount is larger than that of the thin arrows. The same applies to FIGS. 7(a) to (d) described later.

[0026] As shown in FIG. 5(a), the coolant 201 is ejected from the ejection holes 32 and 33 of the coolant ejection member 30. At this time, since the relatively small ejection holes 32 are formed in the upper region 35 and the lower region 37 of the coolant ejection member 30, the ejection amount of the coolant 201 is relatively small. Since the relatively large ejection holes 33 are formed in the central region 36, the ejection amount of the coolant 201 is relatively large. The coolant 201 ejected at the first timing of the cooling process contacts the workpiece 100 and performs heat exchange with the workpiece 100.

[0027] As shown in FIG. 5(b), the coolant 201 that has contacted the workpiece 100 evaporates and forms a vapor layer 202 along the inner surface of the workpiece 100. The vapor layer 202 inhibits the coolant 201 ejected thereafter from reaching the workpiece 100. However, since the ejection amount of the coolant 201 in the central region 36 is larger than the ejection amounts of the coolant 201 in the upper region 35 and the lower region 37, the vapor layer 202 is pushed up and down by the coolant 201.

[0028] Therefore, as shown in FIG. 5(c), the vapor layer 202 is quickly removed, and the coolant 201 contacts the workpiece 100 again. Thereby, the workpiece 100 is continuously cooled.

[0029] A part of the coolant that has contacted the inner surface of the workpiece 100 moves downward within the gap between the coolant ejection member 30 and the workpiece 100, stays on the plate-like member 21 for a short time, contacts the lower surface of the workpiece 100, and then drops. The remaining part of the coolant that has contacted the inner surface of the workpiece 100 moves upward within the gap between the coolant ejection member 30 and the workpiece 100, stays on the workpiece 100 and the cooling jacket 10 for a short time, contacts the upper surface of the workpiece 100, and then mainly drops from the outside of the workpiece 100.

[0030] When the workpiece 100 is sufficiently cooled, the supply of the coolant 201 is stopped and the moving means 60 is stopped. In this way, the quenching device 1 performs a quenching process on the inner surface of the workpiece 100.

[0031] Next, the effects of the present embodiment will be described. In the cooling jacket 10 according to the present embodiment, on the coolant injection surface 31, the area of each injection hole 33 formed in the central region 36 is larger than the area of each injection hole 32 formed in the upper region 35 and the area of each injection hole 32 formed in the lower region 37. Thereby, the vapor layer 202 generated along the inner surface of the workpiece 100 can be quickly discharged up and down, and the coolant 201 injected thereafter can be quickly brought into contact with the workpiece 100. As a result, the cooling efficiency in the central portion in the vertical direction of the workpiece 100 is improved. The central portion in the vertical direction of the workpiece 100 is more difficult to cool compared to the upper and lower portions. Therefore, by improving the cooling efficiency in the central portion in the vertical direction of the workpiece 100, the cooling rate can be made uniform.

[0032] Further, since the plate-like member 21 is provided in the cooling jacket 10, the coolant 201 that has dropped from the gap between the coolant injection member 30 and the workpiece 100 can be retained on the plate-like member 21 for a short time and brought into contact with the lower surface of the workpiece 100. Thereby, the lower surface of the workpiece 100 can also be efficiently cooled. Since the coolant 201 stays on the upper surface of the workpiece 100 for a short time, if the plate-like member 21 is not provided, the cooling rate of the lower surface of the workpiece 100 may be lower than the cooling rate of the upper surface. On the other hand, in the present embodiment, since the plate-like member 21 is provided, the cooling rates of the upper and lower surfaces of the workpiece 100 can be made uniform. Also by this, the cooling rate of the workpiece 100 can be made uniform.

[0033] Further, since the coolant injection member 30 moves relative to the workpiece 100 in the horizontal direction, any position on the inner surface of the workpiece 100 sequentially faces a plurality of injection holes arranged horizontally on the coolant injection surface 31. Therefore, in order to improve the cooling efficiency of the workpiece 100, it is preferable to increase the number of stages of the injection holes in the vertical direction V as much as possible within the rectangular region of the coolant injection surface 31 with which the line segment extending in the vertical direction V on the inner surface of the workpiece 100 faces during a predetermined cooling period.

[0034] In the present embodiment, on the coolant injection surface 31, the densest direction W in which the rows 34 in which the injection holes 32 and 33 are arranged at the shortest intervals extend is inclined with respect to both the horizontal direction H and the vertical direction V. Thereby, within the above-described rectangular region, the number of stages of the injection holes in the vertical direction V can be increased.

[0035] Since the densest direction W is inclined with respect to the vertical direction V, the injection holes 32 and 33 can be densely arranged along the vertical direction V. More specifically, in the example shown in FIG. 4, along the vertical direction V, in the upper region 35, the injection holes 32 are arranged in 4 stages, in the central region 36, the injection holes 33 are arranged in 12 stages, and in the lower region 37, the injection holes 32 are arranged in 3 stages, and the injection holes are arranged in a total of 19 stages. On the other hand, if the densest direction W is made to coincide with the vertical direction V, when the distance D1 is constant, the number of stages of the injection holes along the vertical direction V becomes less than 19 stages.

[0036] On the other hand, also because the densest direction W is inclined with respect to the horizontal direction H, within the above-described rectangular region, the number of stages of the injection holes along the vertical direction V can be increased. More specifically, if the densest direction W is made to coincide with the horizontal direction H, the direction in which the rows 34 are arranged, that is, the direction orthogonal to the densest direction W of the injection holes, coincides with the vertical direction V, and the number of stages of the injection holes in the vertical direction V decreases. In this case, even if the work 100 moves horizontally with respect to the coolant injection member 30, the positions of the injection holes in the vertical direction V do not change, so the effect of increasing the number of stages of the injection holes along the vertical direction V cannot be obtained.

[0037] Furthermore, since the densest direction W is inclined with respect to both the horizontal direction H and the vertical direction V, at the bottom of the teeth between adjacent tooth portions 101 in the work 100, the position where the coolant is injected changes with time. Thereby, at the bottom of the teeth of the work 100, the movement of the coolant along the vertical direction V is generated. Also by this, the cooling rate of the work 100 can be made uniform.

[0038] When the workpiece 100 is annular, the inner surface has a smaller surface area per unit volume compared to the outer surface, making it difficult to cool. Also, when the tooth portion 101 is formed on the workpiece 100, the tooth root has a smaller surface area per unit volume compared to the tooth tip, making it difficult to cool. Therefore, the tooth root on the inner surface of the workpiece 100 generally has low cooling efficiency. In this embodiment, by forming the injection holes 32 and 33 as described above, the cooling efficiency can be improved even at the tooth root on the inner surface of the workpiece 100. As a result, the cooling rate of the workpiece 100 can be made uniform.

[0039] <Comparative Example> Next, the comparative example will be described. FIG. 6 is a side view showing the coolant injection surface of the cooling jacket according to the comparative example.

[0040] As shown in FIG. 6, in the cooling jacket according to this comparative example, a plurality of injection holes 132 are formed in the coolant injection surface 131 of the coolant injection member 130. The sizes of the injection holes 132 are substantially equal to each other. Also, the plurality of injection holes 132 are substantially uniformly distributed on the coolant injection surface 131. Three adjacent injection holes 132 are located at the vertices of an equilateral triangle. That is, the rows 134 in which the injection holes 132 are arranged at the shortest intervals extend in three directions that form an angle of 60 degrees with each other. One of these three directions coincides with the horizontal direction H.

[0041] Next, the operation of the cooling jacket according to the comparative example will be described. FIGS. 7(a) to (d) are diagrams schematically showing the operation of the cooling jacket according to this comparative example.

[0042] As shown in FIG. 7(a), the coolant 201 is injected from the injection holes 132 of the coolant injection member 130. Since the plurality of injection holes 132 are substantially uniformly distributed on the coolant injection surface 131, the injection amount of the coolant 201 is also substantially uniform.

[0043] As shown in Fig. 7(b), the coolant 201 evaporates by contacting the workpiece 100, and forms a vapor layer 202 along the inner surface of the workpiece 100. The vapor layer 202 then inhibits the coolant 201 that is subsequently injected from reaching the workpiece 100. In this comparative example, since the injection amount of the coolant 201 is substantially uniform, the effect of pushing the vapor layer 202 up and down is small.

[0044] As shown in Fig. 7(c), the vapor layer 202 gradually disappears due to the coolant 201 that is subsequently injected. However, during that time, the coolant 201 reaching the workpiece 100 is inhibited, and the cooling efficiency of the workpiece 100 decreases.

[0045] As shown in Fig. 7(d), when the vapor layer 202 is removed, the coolant 201 contacts the workpiece 100 again. Thereby, the workpiece 100 continues to be cooled. Thus, in the comparative example, compared with the above-described embodiment, the discharge of the vapor layer 202 is slow, and the cooling efficiency in the initial stage of the cooling process is low.

[0046] <Test Example> Next, a test example showing the above-described effects will be described. Fig. 8(a) is a partial cross-sectional view showing the workpiece used in this test example, (b) is a graph showing the temperature change of the workpiece during cooling with time on the horizontal axis and temperature on the vertical axis, and (c) is a graph showing the cooling rate in each temperature range with the temperature range during cooling on the horizontal axis and the cooling rate on the vertical axis.

[0047] In this test example, a cooling jacket according to the example described in the above-described embodiment and a cooling jacket according to the comparative example were produced, and quenching treatment was performed on the workpiece 100 using each cooling jacket, and the cooling rate was measured.

[0048] Hereinafter, the test conditions will be described. As shown in Fig. 8(a), in this test example, a swivel ring with a tooth portion 101 formed on its inner surface was used as the workpiece 100. The material of the workpiece 100 was carbon steel S50C. The heat treatment was performed by high-frequency induction heating, and the heating temperature was raised to a high temperature (910 °C) above the austenite transformation point at the center of the tooth root. A polymer solution with a predetermined concentration was used as the coolant.

[0049] In the cooling jacket according to the embodiment, as shown in Figs. 1 to 4, the coolant injection member 30 was used, and the diameter of the injection holes 32 in the upper and lower regions was set to 1.8 mm, and the diameter of the injection holes 33 in the central region was set to 2.4 mm. In the cooling jacket according to the comparative example, as shown in Fig. 6, the coolant injection member 130 was used, and the diameter of the injection holes 132 was set to 1.8 mm. The temperature measurement position 110 was the tooth root at the vertical center of the inner surface of the workpiece 100, at a position 2 mm deep from the surface.

[0050] As shown in Figs. 8(b) and (c), when the cooling jacket according to the comparative example was used, the cooling rate of the workpiece 100 decreased in the initial stage of the cooling process, that is, in the temperature range from 910 °C to 800 °C. On the other hand, when the cooling jacket according to the embodiment was used, in the same temperature range, the cooling rate of the workpiece 100 was higher than that of the comparative example. Thus, according to the embodiment, the cooling rate at the vertical center in the initial stage of cooling was higher than that of the comparative example.

[0051] The foregoing embodiments are examples embodying the present invention, and the present invention is not limited to these embodiments. For example, in the foregoing embodiments, those obtained by adding, deleting, or changing some components are also included in the present invention. For example, the shape of the injection holes on the coolant injection surface is not limited to a circular shape, and may be, for example, a polygonal shape. Further, the distance between adjacent injection holes of the injection hole 33 may be formed narrower than the distance between adjacent injection holes of the injection hole 32. Further, the direction in which the injection holes extend is not limited to the horizontal direction, and may be an obliquely downward direction or an obliquely upward direction. Furthermore, the coolant supply member 20 and the coolant injection member 30 may be integrally formed. Further, the quenching device may perform a quenching process on the outer peripheral surface of the workpiece. In this case, the cooling jacket is disposed outside the workpiece, and the moving means is disposed inside the workpiece. The workpiece is not limited to a swivel ring.

Explanation of Signs

[0052] 1: Quenching device 10: Cooling jacket 20: Coolant supply member 21: Plate-like member 30: Coolant injection member 31: Coolant injection surface 32, 33: Injection holes 34: Column 35: Upper region 36: Central region 37: Lower region 60: Moving means 100: Workpiece 101: Tooth portion 110: Measurement position 130: Coolant injection member 131: Coolant injection surface 132: Injection hole 134: Column 201: Coolant 202: Vapor layer C: Central axis D1~D6: Distance H: Horizontal direction V: Vertical direction W: Most dense direction

Claims

1. A coolant supply member for circulating coolant; A coolant injection member supplied with the coolant from the coolant supply member and having a plurality of injection holes for injecting the coolant; A plate-like member disposed below the gap between the coolant injection member and the work; Comprising: The surface of the coolant injection member facing the work has an upper region, a central region, and a lower region arranged along the vertical direction; The length of the central region in the vertical direction is longer than the length of the upper region in the vertical direction and the length of the lower region in the vertical direction; The area of each injection hole formed in the central region is larger than the area of each injection hole formed in the upper region and the area of each injection hole formed in the lower region; The coolant injection member moves relatively in the horizontal direction with respect to the work; A cooling jacket in which the densest direction in which the plurality of injection holes are arranged at the shortest interval is inclined with respect to both the horizontal direction and the vertical direction.

2. The work is annular; The cooling jacket according to claim 1, wherein the coolant injection member faces the inner surface of the work.

3. The work is annular; The cooling jacket according to claim 1, wherein a plurality of tooth portions arranged in the circumferential direction of the work are provided on the surface of the work facing the coolant injection member.

4. A quenching device comprising the cooling jacket according to any one of claims 1 to 3; Heating means for heating the work.

5. The quenching device according to claim 4, further comprising moving means for relatively moving the work with respect to the coolant injection member. ​

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