JP2010242153A - Cooling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high frequency-induction hardening apparatus with which objective material can efficiently be cooled with a little volume of cooling liquid by improving the holes for discharging the cooling liquid, such as cooling water. <P>SOLUTION: A cooling device 2 is provided with a jacket 8 which is relatively shiftable to the steel tube 7 for supporting a plurality of nozzles 11 on the surface faced to a steel tube 7, and a water-supplying device 9 for supplying the cooling water into the plurality of nozzles 11. Each of the plurality of nozzles 11 is formed by setting a spiral-shaped member in the inner part of an outer-coating tube. At the tip-end part of the outer-coating tube, an outlet hole of cooling water is arranged, and at the other-end of the outer-coating tube, an inlet hole of cooling water is arranged, and the diameter of the outlet hole is made to be smaller than the outer diameter of the spiral-shaped member. The cooling water supplied into the jacket 8 with the water supplying device 9, is entered into the inner part of the nozzle 11, and after giving a spiral-movement with the spiral-shaped member, the cooling water is spread and discharged as the drill-state from the outlet hole of the nozzle 11 and hit to the steel tube 7 to cool the steel tube 7. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling device suitably used for heat treatment such as quenching and annealing.

  It is widely performed in the industry to perform a heat treatment in order to adjust a steel member to characteristics according to the purpose. In the heat treatment, generally, a steel member is heated to a predetermined high temperature, and then the heated steel member is cooled.

  For example, in order to extend the life of a small and light steel structural component, the structural component may be subjected to surface hardening treatment. Conventionally, various methods are known for realizing surface hardening treatment. Induction hardening is known as one of them. In this induction hardening, a high frequency is applied to a steel workpiece to be quenched to generate induction heat to heat the workpiece until it exhibits a predetermined phase, and the heated workpiece is rapidly cooled at a predetermined cooling rate. The surface of the workpiece is hardened by cooling.

  When considering a phenomenon in which heat is transmitted, heat conduction is a phenomenon in which thermal energy moves in a direction in which the temperature becomes uniform. On the other hand, heat transfer is a phenomenon in which heat moves between a solid surface and a fluid in contact therewith. The cooling treatment used in the induction hardening described above is a method for realizing heat transfer by continuously applying (that is, contacting) cooling water to a solid surface at a constant flow rate, and utilizes a phenomenon belonging to forced convection heat transfer. Cooling method.

  If high-frequency induction heating is used, the structural part can be heated to a predetermined quenching temperature in a short time, and therefore, the mechanical properties having a fine structure after heat treatment and excellent ductility and toughness can be obtained. . In addition, only a part of the structural component can be cured, and the properties of the material can be effectively extracted with little thermal distortion.

  Moreover, according to the heating using a high frequency, it is not necessary to heat the whole workpiece | work, it is excellent in thermal efficiency and energy saving is obtained. In addition, the temperature can be raised quickly, the working time can be shortened, the surface after heat treatment has little oxide scale, and the post-process for surface cleaning can be omitted. As a result, cost reduction can be achieved. Furthermore, it is easy to change the frequency and output of the high frequency applied to the coil in order to generate heat, and the heating coil and cooling system can be combined as appropriate, so the system design of the entire quenching system is free. High degree.

  As described above, induction hardening has many advantages and is used in a wide range of industrial fields. For example, conventionally, according to the cited document 1, the ERW steel pipes 11 and 12 as workpieces are heated to a predetermined temperature by the high frequency induction heating coil 30, and then a plurality of injections provided on the inner peripheral surface of the cooling water chamber 43. The ERW steel pipes 11 and 12 are quenched by injecting the cooling water 45 from the holes 44 toward the ERW steel pipes 12 to cool the ERW steel pipes 11 and 12 to the cooling water temperature. Induction hardening devices are known.

  Further, according to the cited document 2, the cooling device is configured by using the flat spray nozzle 4c, and the high-frequency radiation which is radiated from the entire flat spray nozzle 4c is radiated cooling water having a shape spreading on the downstream side in the traveling direction. A quenching device is known. In this apparatus, it is considered that the cooling water is sprayed linearly from the individual spray holes constituting the flat spray nozzle 4c.

  Further, according to the cited document 3, a ring-shaped slit-shaped injection port 15 is provided inside the jackets 12, 13, and the cooling liquid is sprayed in a film shape from the injection port 15 toward the work 10 in an inverted conical shape. A method is disclosed.

JP-A-7-054048 (page 2-4, FIG. 1-2) JP-A-8-253817 (page 7, FIG. 9) CD-ROM (4th page, Fig. 2) of Japanese Utility Model Application No. 2-083528 (Japanese Utility Model Application Publication No. 4-040752)

  In each of the conventional induction hardening apparatuses described above, in the cooling section that cools the heated workpiece, a cooling liquid, for example, cooling water, is ejected from each of the numerous holes into a linear shape, that is, a beam shape having a uniform cross-sectional diameter. Then, they were put on the work and the work was cooled. That is, in the conventional cooling unit, the workpiece is cooled by applying the coolant to the workpiece in a shower shape from a plurality of small holes.

  By the way, when cooling water is applied to a workpiece heated to a high temperature, a vapor film is generated on the surface of the workpiece. Since this vapor film has a low heat transfer coefficient, there is a possibility that inconveniences such as uneven cooling, insufficient quenching hardness, bending of the workpiece, etc. will occur if no measures are taken. In recent years, it has been required to increase the processing speed for quenching. For example, regarding the quenching treatment of high-tensile steel pipes for door impact beams (door impact beams) used in automobiles, the conventional general processing speed was 60 mm / sec, but is now 300 mm / sec. Has reached the speed of about. As described above, when the quenching processing speed is increased, the above-described inconvenience associated with the generation of the vapor film becomes more remarkable.

  In order to efficiently cool the workpiece in spite of the generation of the vapor film, it is effective to suppress the generation of the vapor film or allow the cooling water to penetrate the vapor film and reach the workpiece. For these reasons, it is necessary to sufficiently increase the speed of the cooling water. In the conventional case where the cooling water is supplied to the work in a shower form, in order to sufficiently increase the flow speed of the cooling water hitting the work under a predetermined pressure, a large amount of cooling water is supplied to the numerous holes for discharge. It is necessary to supply.

  However, in a shower-type cooling device having a structure in which cooling water is discharged from a plurality of simple small-diameter holes, it is very difficult to obtain a desired flow velocity with respect to the liquid by adjusting the hole diameter and the distance between holes (so-called pitch). It was difficult.

  Hereinafter, the general characteristics of the cooling device used for heat treatment such as quenching and annealing will be described, and the conventional problems will be described by giving one conventional example of the cooling device.

(A) Description of General Cooling Device In the following description, a case where induction hardening is performed as heat treatment is illustrated.
(A) Dimensions and Material First, as a workpiece to be quenched, a steel pipe having an outer diameter of 31.8 mm to 25.4 mm and a thickness of 1.4 mm to 2.8 mm, particularly an outer diameter of 31.8 mm and a thickness of 2. Consider hardening a 0 mm steel pipe. This steel pipe shall be manufactured with high-tensile steel. This work is a steel pipe suitable as an automobile door impact beam.

(B) Workpiece transport speed In many conventional quenching processes, high-frequency heating and cooling processes are performed while transporting a work, and the work transport speed at that time was about 60 mm / sec. However, recently, a high conveyance speed of 300 mm / sec may be reached.

(C) Rapid water cooling In this specification, “rapid water cooling” in the quenching process refers to supplying a cooling water having a constant flow rate to a red-heated steel pipe on the outer surface of the steel pipe without interruption. The temperature of the outer surface of the steel pipe is kept close to the temperature of the cooling water, the temperature of the entire steel pipe is lowered to near the temperature of the cooling water by heat conduction, and the steel pipe is quenched. In addition, although a cooling medium is a liquid which is not restricted to cooling water, in order to make description easy to understand, the following description considers a cooling medium as cooling water.

(D) Time required for cooling The steel pipe made of the above material and having the above dimensions is heated until it exhibits a predetermined phase state, for example, heated to 950 ° C., and its outer surface is instantaneously lowered to the temperature of the cooling water, and the entire steel pipe The time required to lower the temperature to near the cooling water temperature is about 1.4 seconds from a general heat conductivity calculation.

(E) Diameter of cooling water discharge hole Generally, a cooling device is provided with a plurality of cooling water discharge holes in a structure such as a jacket, and the cooling water discharged from these holes is applied to the work. The cooling is done. The hole diameter of a shower used in a bath or the like is a small diameter of about 0.5 mm. Tap water does not contain impurities and there is no worry of clogging. On the other hand, when cooling the red hot metal as in the present invention, the cooling water is circulated and used, but metal pieces such as an oxide film peeled off from the metal during cooling are mixed in the cooling water. Although the cooling water circulation system is provided with a filter and measures are taken to minimize clogging due to contaminants, there is still a limit to reducing the hole diameter. In addition, there is a limit to reducing the hole diameter from the economical aspect in drilling. From these circumstances, the diameter of the cooling water discharge hole is generally about φ2.0 mm in diameter.

(F) Cooling water flow velocity and flow rate to counter the vapor film The temperature at which the cooling water is gasified depends on the pressure, but when the temperature of the steel pipe surface is higher than the temperature at which the cooling water is gasified, the cooling water Gasification occurs at the moment of contact with the surface of the steel pipe, and gas (water vapor) enters between the cooling water and the surface of the steel pipe. Since water vapor does not cause a convection phenomenon and stays on the steel pipe surface for a long time, the heat transfer coefficient from the steel pipe surface to the cooling water becomes low. Moreover, the heat transfer coefficient of water vapor is as low as about 1/10 of water. For these reasons, heat exchange between the cooling water and the steel pipe surface when a vapor film is generated is not sufficiently performed. In particular, when the flow rate of cooling water is slow, a vapor film is generated between the steel pipe and the cooling water at the moment when the cooling water is applied to the surface of the heated steel pipe, resulting in poor cooling efficiency and insufficient quenching. There is a risk.

  Generally, when the flow rate of cooling water is increased, the generation of a vapor film can be suppressed, and even if a vapor film is generated, the vapor film can be broken through. It has been found by experiments of the present inventor that the flow rate at which the suppression of the generation of a vapor film or the like can be realized for a steel tube heated to 950 ° C. is at least 15 m / sec.

The water pressure to obtain this flow rate should be at least about 3 kg / cm ² . At this time, the flow rate through one hole having a diameter of 2.0 mm is at least about 3 L (liter) / min = 50 cc / sec.

  The flow rate from one hole depends on the water pressure and pipe resistance (i.e., the length of the hole), but the thickness (i.e., length) of the cooling water discharge hole of a normal jacket is about 2 to 3 mm. The flow rate change between the plate thicknesses of 2 mm and 3 mm is about several percent.

(B) Characteristics of Conventional Example of Cooling Device Used in Induction Hardening Device (a) Conventional Example of Cooling Device First, a conventional example will be described. FIG. 11 shows an example of a conventional shower type cooling device. (A) is a front view, (b) is sectional drawing. The cooling device 52 includes a jacket 58 that surrounds the conveyance path of the steel pipe 57, and a water flow pipe 59 that supplies cooling water to the inside of the jacket 58. A plurality of simple through holes 61 are provided in an oblique direction with respect to the conveyance path of the steel pipe 7 on the inner surface of the jacket 58 which is a surface facing the conveyance path of the steel pipe 57. Regarding the holes 61, it is assumed that 16 holes in one row along the conveying direction A of the steel pipe 57 are provided in 12 rows in the circumferential direction, and therefore the total number of holes 61 is 192.

  The cooling water supplied to the inside of the jacket 58 is discharged from each of the plurality of holes 61 toward the conveyance path of the steel pipe 57. The cooling water thus discharged hits the steel pipe 57, and the steel pipe 7 is cooled and quenched. The hole diameter of the hole 61 is about φ2.0 mm as described above in general.

  FIG. 12 shows the steel pipe 57a in a developed state where the cooling water is supplied by the cooling device 52 of FIG. The length La along the conveyance direction A of this portion is 63.9 mm. The circumferential length Lb of this portion is 99.9 mm because the diameter of the steel pipe is 31.8 mm. And the plate | board thickness t of a steel pipe is 2.0 mm.

(B) Required cooling water amount calculated based on the material characteristics of the steel pipe 57 Hereinafter, it is necessary to quench a steel pipe having a diameter of 31.8 mm and a thickness of 2.0 mm using the conventional cooling device 52 shown in FIG. The amount of cooling water is determined based on the material characteristics of the steel pipe 57.
(A) First, the volume V1 of the steel pipe surface to which the cooling water hits is shown in FIG.
V1 = La × Lb × t
= 63.9 × 99.9 × 2.0
= 12.767 (cm ³ )
It is.

(A) Next, since the specific gravity G1 of the steel pipe is 7.9, the specific heat H1 is 0.15, and the heating temperature T1 of the steel pipe is 950 ° C., the amount of heat N1 required for cooling is
N1 = V1 × G1 × H1 × T1
= 12.767 × 7.9 × 0.15 × 950
= 14,372 cal
It is.

    (C) Next, the rising temperature T2 of the cooling water at 0 ° C. is set to 10 ° C. As the temperature rise T2 is set higher, the required flow rate decreases, but the rapid cooling condition is not satisfied and quenching becomes insufficient. The rising temperature set value of T2 = 10 ° C. is a numerical value based on experience.

    (D) Next, the time t1 required for rapid cooling to a quenchable temperature (that is, normal temperature) is 1.4 seconds as described above.

    (E) Next, the heat transfer rate when the flow rate of the cooling water is 15 m / sec is 100%.

(F) The required cooling water flow rate Q1 under the above five conditions (a) to (e) is:
Q1 = N1 / t1 / T2
= 14,372 / 1.4 / 10
= 1,027cc / sec
= 61.62L / min
It is.

(C) Cooling capacity of the cooling water discharge hole 61 (A) If the surface area of the portion of the steel pipe 57 that is cooled by the cooling water is SA57, this is the area of the steel pipe surface portion 57a shown in FIG.
SA57 = (outer diameter of steel pipe 57) × π × (length La along conveyance direction A)
= 31.8 × π × 63.9
= 6380mm ²
It is.

(A) If the cooling area by the cooling water through the hole 61 of the jacket 58 is RA61,
RA61 = (hole diameter of hole 61/2) ² × π × (number of holes)
= (2/2) ² × π × 192
= 603mm ²
It is.

(C) From the above, the cooling area ratio RAR61 for the steel pipe 57 by the hole 61 is
RAR61 = RA61 / SA57
= 603/6380
= 0.095

(D) Overall flow rate of cooling water necessary for solving the problem of the vapor film “Cooling water flow velocity and flow rate to counter the vapor film” column in the “General description of cooling device” column (A) above ( As explained in f), in a general cooling device, the cooling water flow rate is 3 kg / cm ² when the flow rate of cooling water required for generating or breaking through the steam film on the work surface is 3 kg / cm ^2. 3 L / min for a single hole.
Therefore, the total flow rate FR52 of the cooling water necessary for not generating or piercing the steam film around the steel pipe 57 in the cooling device 52 of FIG.
FR52 = flow rate x number of holes
= 3L / min x 192
= 576L / min ... (F1)
It is.

(E) Regarding the area of the steel pipe 57 cooled by the cooling water ejected from all the holes 61 of the jacket 58:
(A) The cooling water discharged from the cooling water discharge hole 61 in FIG. 11 hits the steel pipe surface 57a in a dot shape, that is, an island shape, as depicted in FIG. Since the cooling water is discharged obliquely with respect to the steel pipe 57, the above dot shape is actually not an exact circle but an ellipse or an ellipse, but is depicted as a perfect circle in the figure.

(A) The sectional area of the cooling water directly hitting the surface of the steel pipe 57 / the surface area of the steel pipe 57 = the “cooling area” of the jacket 58.
(C) In addition to this cooling area, when cooling water is directly applied to the surface of the steel pipe 57, there is a “substantially cooling area” that is cooled radially by the heat conduction around the contact surface of the cooling water (FIG. 13). (See symbol E). In FIG. 13, the hatched circular portion indicates the range in which the temperature of the outer surface of the steel pipe 57 approaches the cooling water temperature when the temperature immediately below the surface of the outer surface of the steel pipe 57 that contacts the cooling water is close to the cooling water temperature. Is shown. That is, the cooling range of the outer surface of the steel pipe 57 when the cooling range of the φ2 mm hole on the outer surface of the steel pipe 57 immediately after the start of cooling and the cooling range of the inner surface of the steel pipe 57 become the same shape φ2 mm as time passes. Show.

(D) Consider the area where the steel pipe 57 is substantially cooled.
(I) Considering that the heat conduction range TC according to the passage of time is that heat conduction proceeds in the thickness direction,
TC = (hole diameter 2 mm) + (radially extending distance 2 mm) + (2 mm)
= Φ6mm
It becomes.
(Ii) Since the sectional area of φ6 mm is 28.3 mm ² , the substantial cooling area SRA58 by the jacket 58 is
SRA58 = 28.3 × 192
= 5433mm ²
It is.
(Iii) Therefore, the effective cooling area ratio RSRA58 by the jacket 58 is
RSRA58 = substantially cooled area (SRA58) / cooled steel pipe 57 surface area (SA1)
= 5433/6380
= 0.85
It is.

        (Iv) By the way, FIG. 14 shows a portion where the cooling is insufficient in the thickness direction of the steel pipe 57 in relation to the mutual positional relationship of the plurality of substantial cooling areas E. As indicated by reference sign W1 in FIG. 14, there are 21.5% of the portion where the cooling is insufficient in the thickness direction of the steel pipe 57. In the range indicated by W1 (ie, the range surrounded by the curved line R2), the cooling direction is more than the thickness of the plate, and therefore in the heat conduction calculation, the insufficient cooling region is more than 21.5%, but the calculation is simplified. Therefore, the content is set to 21.5%. The range indicated by W2 corresponding to the contact diameter φ2 mm is a range in which the plate thickness is sufficiently cooled.

(Iii) Therefore, the final effective cooling area ratio RSRA58 is
RSRA58
= (Substantially cooled area SRA58 × cooling sufficient area) / (steel pipe surface area SA1 to be cooled)
= 5433 × 0.785 / 6380
= 0.67
It becomes.
For reference, in order to completely cool the 21.5% portion, which is an insufficiently cooled region, it takes about twice as long as the cooling time required to cool the plate thickness from the heat conduction calculation. become.

(F) Current state of cooling device 52 with respect to “total cooling water flow rate of 576 L / min necessary to eliminate vapor film problem” (see column (d) above) As described in column (d) above, the steel pipe In order to suppress the vapor film generated on the surface of 57 or break through the vapor film, a flow rate of cooling water of 576 L / min in total is required. However, a large amount of equipment costs are required to construct a circulation facility for recovering and reusing such a large amount of cooling water after the cooling treatment. Moreover, it is very difficult to construct a mechanism for treating the cooling water that bounces off the steel pipe 57.

For these reasons, in the current cooling apparatus, the quenching process is performed in a state where the water pressure of the cooling water is lowered and the flow rate of the cooling water is reduced to about 150 L / min. The water pressure of the cooling water at this time is about 0.5 kg / cm ² , and the flow rate is about 5.7 m / sec. Thus, since the water pressure and flow rate of the cooling water were reduced, the heat transfer rate for the cooling water was lowered, and the conditions for rapidly cooling the steel pipe 57 became insufficient, resulting in insufficient quenching hardness and The bending of the steel pipe 57 after quenching frequently occurred.

(G) Ideal cooling jacket When considering a cooling device with a structure in which a plurality of through-holes are arranged side by side as in the conventional cooling device and cooling water is supplied to the steel pipe in a shower form from these holes, sufficient quenching treatment An ideal cooling jacket that can perform the following can be configured as follows.

  That is, in FIG. 15, the pitch (that is, the distance between the holes) P61 of the cooling water discharge holes 61 is set to 2 mm. This setting is determined based on the actual cooling area SRA58 obtained in (e), (d) and (ii) above.

In FIG. 12, the circumferential length Lb of the steel pipe 57 is 99.9 mm, and the length La by which the steel pipe 57 is cooled is 63.9 mm. Therefore, if the pitch of the holes 61 is set to 2 mm as described above, The total number N61 of 61 is
N61 = (Lb / 2) × (La / 2)
= (99, 9/2) x (63.9 / 2)
= 1600
It is.

In the above (B), (b) and (f), the required cooling water amount Q1 calculated based on the material characteristics of the steel pipe 57 was 61.62 L / min. The total number of holes 61 is 1600 as described above. Therefore, the required flow rate Q1 / N61 per hole 61 is
(Q1 / N61) = 61.62 / 1600
= 0.0385 L / min
It is.

As described in the above (A) and (f), in a general cooling device, when cooling water is discharged from a plurality of holes of φ2.0 mm, one piece necessary for solving the problem of the vapor film The flow rate from the hole was 3.0 L / min. Therefore, if the hole diameter of the hole 61 that can realize the flow rate of 0.0385 L / min is X,
X: 2 = 0.0385: 3.0
And therefore
X = 0.23mm
It is. That is, the required hole diameter of the hole 61 is 0.23 mm. The substantial coolable outer diameter RD at this time is RD = φ4.23 mm.

  As described above, an ideal number of holes = 1600 and a hole diameter = φ0.23 mm are obtained. Such a hole can usually be manufactured by laser processing, but the manufacturing cost becomes very high. Moreover, since the hole diameter is small, the problem of clogging of the hole occurs when the cooling water is circulated and reused. Therefore, the ideal configuration shown in FIG. 15 is practically difficult to manufacture.

  The present invention is made in order to solve the above-mentioned problems in the conventional apparatus, and improves the hole for discharging the cooling liquid such as cooling water, so that the work can be efficiently performed with a small amount of the cooling liquid. It is an object of the present invention to provide a cooling device for a quenching device that can be cooled well.

  The cooling device according to the present invention is a cooling device that cools a target object by bringing a coolant into contact with the heated target object, and is movable relative to the target object and faces the target object. A support that supports a plurality of nozzles on a surface, and a coolant supply means that supplies the coolant to the plurality of nozzles, wherein at least one of the plurality of nozzles has a space inside, and the cooling An outer tube having an outlet hole for discharging the liquid at the tip and an inlet hole for receiving the cooling liquid at the other end; and a spiral-shaped member provided inside the outer tube; At least one spiral surface which is a spiral surface is provided on the outer peripheral surface of the shape member, the spiral surface is opposed to the inner peripheral surface of the jacket tube, and the diameter of the outlet hole is the spiral. It is smaller than the outer diameter of the shape member and is supplied by the coolant supply means. Cooling liquid, the through inlet hole enters the inside of the outer casing tube, characterized in the that emitted from the exit hole spreads conical After flowing along the helical surface.

  The cooling device of the present invention is a cooling device that is suitably used for a heat treatment device such as a quenching device or an annealing device, and is a cooling device that cools an object by applying a coolant to the object (that is, contacting it). It is. The cooling liquid is, for example, cooling water. The cooling water can be set to room temperature, that is, a temperature at which heating and cooling are not performed. The temperature of the cooling water may be set to a temperature other than room temperature as necessary.

  The support is, for example, a jacket arranged so as to surround an object. The jacket has an internal space that surrounds the object in an annular shape, and a coolant is held inside the internal space. And the said some nozzle is provided in the internal peripheral surface of a jacket, and a cooling fluid is discharge | released from these nozzles.

  According to the cooling device of the present invention, since the cooling liquid is applied to the object in a conical shape from the outlet hole of the nozzle, compared to the shower system that is configured to discharge the linear cooling liquid. The desired area of the object can be accurately cooled with a small amount of the coolant.

  In addition, in the present invention, since the cooling hole is discharged from the outlet hole by imparting a spiral motion to the cooling liquid, the flow speed of the cooling liquid can be maintained stably and quickly, and the generation of a vapor film can be suppressed. Further, even if a vapor film is generated, the coolant can break through it and cool the object accurately.

  Furthermore, by appropriately changing the helical angle of the helical member, the cooling liquid discharge angle can be changed as desired, and the cooling capacity can be appropriately selected according to the characteristics of the object.

  In the cooling device according to the present invention, it is preferable that an outer peripheral edge of the spiral-shaped member is in contact with an inner peripheral surface of the jacket tube. The outer peripheral edge is an outer edge line existing on the outermost side of the helical member. This outer edge line also draws a spiral. If the outer peripheral edge of the spiral-shaped member is in contact with the inner peripheral surface of the outer tube, the helical space formed between the outer tube and the helical surface can be accurately defined without a gap. A stable spiral motion without any disturbance can be imparted to the coolant supplied to the inside of the tube, and as a result, a coolant having a stable flow rate and flow rate can be discharged from the outlet hole of the jacket tube.

  In the cooling device according to the present invention, the spiral-shaped member can be a rod-shaped member, and can have a plurality of spiral surfaces arranged in a circumferential direction around its center axis on its outer peripheral surface. . By providing a plurality of spiral surfaces, a coolant having a stable flow rate and flow velocity can be discharged from the outlet hole of the jacket tube.

  In the cooling device according to the present invention, the spiral surface may be a flat plane. In this way, the helical member can be easily manufactured. The spiral surface may be a curved surface that is curved toward the central axis of the spiral-shaped member. In this way, the area in the cross section perpendicular to the axis of the helical member in the helical space formed between the outer tube and the helical surface can be increased and discharged from the outlet hole of the outer tube. The flow rate of the coolant can be increased.

  In the cooling device according to the present invention, a groove can be provided in the surface of the spiral surface. According to this configuration, cooling is performed by both the spiral space formed between the spiral surface and the inner peripheral surface of the outer tube and the spiral space formed between the groove and the inner peripheral surface of the outer tube. A spiral motion can be imparted to the liquid. According to this configuration, the flow rate and flow rate of the coolant can be finely adjusted depending on the size and shape of the groove.

  In the cooling device according to the present invention, the spiral angle of the spiral surface is a spiral angle capable of distributing the coolant over the entire surface from the center point to the outer peripheral edge of the coolant contact surface on the surface of the object. Can do. With this configuration, it is possible to increase the cooling capacity of the object by the coolant. Of course, if necessary, the coolant can be intentionally applied to a portion of the coolant contact surface. The spiral angle is an angle formed between the tangent line of the outer edge line of the spiral surface and the center line of the spiral (that is, the center line of the spiral member).

  In the cooling device according to the present invention, the manufacturing method of the spiral member is not limited to a specific method, but for example, the following method can be adopted. That is, a rod-shaped core material is prepared, and a predetermined spiral surface is formed on the outer peripheral surface of the core material. The core material is preferably formed of a metal such as high-strength steel in order to reduce wear due to the impact of water flow. By twisting the core material about its own central axis, the planned spiral surface is twisted into a spiral shape around the central axis, thereby forming a spiral surface. Such a method of forming a spiral surface can be realized very easily, and the spiral angle can be adjusted with high accuracy.

  According to this method for manufacturing a spiral-shaped member, when there is one planned spiral surface, one (that is, one) spiral surface is formed around the central axis. Then, when there are n spiral planned surfaces (n is a positive integer), n (n strips) spiral surfaces are formed.

  For example, as shown in FIG. 9A, the planned spiral surface may be a rectangular flat surface 16 that is formed on the side surface of a cylindrical rod-shaped core member and extends in the central axis direction of the core member. Since the flat surface 16 is one flat surface, the spiral surface formed by twisting the flat surface 16 is one line. Moreover, as shown in FIG.9 (b), the four outer peripheral surfaces 17 (all are flat planes) of a square-column-shaped rod can also be made into a spiral planned surface. There are four spiral surfaces formed by twisting these four surfaces 17.

  Moreover, as shown in FIG.9 (c), the four curved surfaces 18 which curve toward the center axis line X0 of a core material can also be made into a helical plan surface. There are four spiral surfaces formed by twisting these four surfaces 18. Furthermore, as shown in FIG. 9 (d), two curved surfaces 19 that are curved toward the central axis X0 of the core material and that are in a relation of the front and back can be used as the predetermined spiral surfaces. There are four spiral surfaces formed by twisting these two surfaces 19.

  In the cooling device according to the present invention, it is preferable that the plurality of nozzles are provided at different positions along a moving direction of the object relative to the support. With this configuration, the contact surface of the coolant with respect to the object can be increased with respect to the moving direction of the object, and therefore the cooling effect on the object with the coolant can be enhanced.

  In the cooling device according to the present invention, the plurality of nozzles may be provided at different angular positions around the moving path of the object in a plane perpendicular to the moving direction of the object with respect to the support. preferable. With this configuration, the contact surface of the coolant with respect to the object can be increased in the direction perpendicular to the moving direction of the object, and therefore the cooling effect on the object with the coolant can be enhanced.

In the cooling device according to the present invention, the plurality of nozzles may be provided at different positions along a moving direction of the object relative to the support. The plurality of nozzles can be provided at different angular positions around the moving path of the object in a plane perpendicular to the moving direction of the object with respect to the support. Moreover, among these nozzles, the nozzles belonging to the nozzle group adjacent to each other along the moving direction of the object with respect to the support are mutually in relation to the angular position around the moving path of the object. It can be displaced.
With this configuration, it is possible to increase the distribution density of the contact surface of the cooling liquid on the surface of the object, and therefore it is possible to increase the cooling efficiency.

  In the cooling device according to the present invention, the object may be a heated steel pipe, and the coolant may be water at room temperature or lower, which is a normal temperature that is not heated and cooled. According to this aspect of the present invention, the steel pipe can be efficiently cooled with a small amount of water, which can greatly contribute to cost reduction.

  According to the cooling device according to the present invention, since the cooling liquid is applied to the object in a conical shape from the outlet hole, it is less than the shower method that is configured to discharge the linear cooling liquid. The desired area of the object can be accurately cooled with an amount of coolant.

  Furthermore, since the cooling hole is discharged from the outlet hole by imparting a spiral motion to the cooling liquid, the flow rate of the cooling liquid can be stably and rapidly maintained, and the generation of a vapor film can be suppressed. Further, even if a vapor film is generated, the coolant can break through it and cool the object accurately.

  Furthermore, by appropriately changing the helix angle of the helical surface of the helical member, the discharge angle of the cooling liquid can be changed as desired, and the cooling capacity can be appropriately selected according to the characteristics of the object.

It is a figure which shows the induction hardening apparatus which is the usage example of the cooling device which concerns on this invention. It is sectional drawing which shows one Embodiment of the cooling device which concerns on this invention. It is sectional drawing in each position of (a), (b), (c), (d) of FIG. It is a figure which shows an example of the nozzle which is a discharge | release unit for discharging | emitting the water which is a cooling liquid, (a) is sectional drawing seen from one side, (b) is whole side sectional drawing, (c) is from the other side FIG. It is a perspective view which shows the core material which is the main components of the helical member which is a structural requirement of a nozzle. It is a figure which shows the contact surface of the cooling water formed when the cooling water discharged | emitted from the nozzle hits the steel pipe which is a target object, (a) shows the state where a cooling water does not spread in the center part, (b ) Shows a state in which cooling water is distributed over the entire contact surface. FIG. 3 is a development view showing cooling water contact surfaces at positions (a), (b), (c), and (d) in FIG. 2. It is a figure for demonstrating the substantial cooling area of a cooling water. It is a figure which shows the modification of the main components shown in FIG. It is a figure which shows the state accommodated in the jacket pipe, after twisting the main components shown in FIG. It is a figure which shows an example of the conventional cooling device, (a) shows the front view, (b) has shown sectional drawing. It is an expanded view of the steel pipe which shows the contact surface of the cooling water formed in the surface of the steel pipe which is a target object with the conventional cooling device shown in FIG. FIG. 13 is a development view of a steel pipe showing a substantial cooling area based on a contact surface of the cooling water in FIG. 12. It is a figure which shows the state which the area | region where cooling becomes inadequate in the plate | board thickness direction of the steel pipe which is a cooling target in the conventional cooling device generate | occur | produced. It is a figure which shows the ideal structure about the structure of the ejection hole of the cooling water employ | adopted with the conventional cooling device.

  At present, in order to reduce damage to passengers at the time of automobile collision, a steel pipe having high tensile strength is attached to each door of the automobile. A steel pipe having a high tensile strength is formed, for example, by subjecting a steel pipe made of high-tensile steel to a quenching process. Specifically, for example, an electric resistance welded tube is manufactured from a high-strength steel band steel using a high frequency electric resistance welded tube manufacturing apparatus, and then the electric resistance welded apparatus is uniformly quenched in the thickness direction of the electric resistance welded tube.

As a more specific method, for example,
(1) An induction hardening device is installed on-line (that is, continuously or directly connected) to the high-frequency electric resistance welded tube manufacturing apparatus, and the process from the manufacture of the long length of the electric resistance welded tube to the quenching process is performed continuously. A method of cutting the sewing tube into the length of the final product,
(2) A fixed-size (for example, 5.5 m) ERW pipe is manufactured in advance by an ERW pipe manufacturing apparatus, and is quenched by an induction hardening apparatus in another place (that is, off-line). A method of cutting the ERW tube into the length of the final product, or (3) the ERW tube of the length of the final product is manufactured by the ERW tube manufacturing apparatus, A method is conceivable in which the ERW pipe manufactured in 5.5 m) is cut off-line to the length of the final product, and then the ERW pipe is continuously heated and cooled as if it were connected in a daisy chain.

  In the present embodiment, the present invention is applied to the induction hardening apparatus according to the method (3). This method is suitable for mass production because of its high processing capacity and low production costs.

  FIG. 1 shows an overall configuration of an induction hardening apparatus that can realize the method (3). In FIG. 1, the vertical direction is the vertical direction, and the horizontal direction is the horizontal direction. The induction hardening apparatus denoted as a whole by reference numeral 21 has a steel pipe transport device including a steel pipe rapid feed mechanism 22 and a steel pipe transport mechanism 23. This steel pipe transport device has a support transport device that can support and transport a plurality of steel pipes 7 in the axial direction, for example, a roller conveyor, a belt conveyor, etc. (not shown). A conveyance path of the steel pipe 7 defined by the support conveyance device is indicated by a chain line C. A chain line C also indicates the central axis of the steel pipe 7. Further, the conveying direction of the steel pipe 7 is indicated by an arrow A.

  The steel pipe rapid feed mechanism 22 transports the steel pipe 7 faster than the steel pipe transport mechanism 23. Therefore, no space S is generated between the steel pipes 7 between these mechanisms, and no space is generated between the steel pipes 7 even on the subsequent steel pipe conveyance path. That is, the plurality of steel pipes 7 are continuously transported in the axial direction in a so-called beaded manner without interruption.

  The induction hardening device 21 includes steel pipe rotating mechanisms 24 a, 24 b, 24 c, a heat treatment device 1, a cooling device 2, and a payout mechanism 28. The steel pipe rotating mechanisms 24 a, 24 b, 24 c, the high-frequency heating device 1, the cooling device 2, and the payout mechanism 28 are all arranged on the conveyance path C of the steel pipe 7.

  In the induction hardening device 21, the steel pipe 7 is continuously transported along the steel pipe transport path C by the steel pipe fast-forward mechanism 22 and the steel pipe transport mechanism 23 without a gap. The steel pipe 7 to be conveyed is fed into the high-frequency heating device 1 and the cooling device 2 while being rotated about its own central axis by the steel pipe rotating mechanisms 24a, 24b, and 24c.

  The high frequency heating apparatus 1 heats each steel pipe 7 to a predetermined phase region. For example, the entire plate thickness in the radial direction of the steel pipe 7 is rapidly heated to about 950 ° C. The heated steel pipe 7 is then rapidly cooled by the cooling device 2, whereby each steel pipe 7 is quenched. In the present embodiment, it is assumed that quenching is performed by cooling the steel pipe with water using cooling water as the cooling liquid. Cooling water temperature is normal temperature. The normal temperature is a normal temperature that is not heated and cooled. The steel pipe conveyance speed during quenching is as high as about 300 mm / sec. After cooling the steel pipe, the steel pipe 7 is paid out to the outside of the conveyance path C by the pay-out mechanism 28. Furthermore, the tensile strength of the steel pipe 7 is measured by the total number or a predetermined number of extractions, the bending dimensions are further measured, and those that fall within the predetermined allowable dimensions are carried out as products.

  The outer diameter of the steel pipe 7 is usually φ31.8 mm to φ25.4 mm, and the plate thickness is 1.4 mm to 2.8 mm. In many cases, the outer diameter of the steel pipe is φ31.8 mm. The plate thickness and length of the steel pipe are set to various values according to the type of vehicle. In this embodiment, a steel pipe used for the door impact beam, for example, a high-tensile steel with a diameter D = φ31.8 mm, a plate thickness t = 2.0 mm, and a length is quenched.

  The high-frequency heating device 1 heats the steel pipe 7 using an electromagnetic induction phenomenon by injecting a high-frequency force into the steel pipe 7 to be conveyed. In the present embodiment, the steel pipe 7 is heated to a temperature of 950 ° C., and a predetermined phase change is caused inside the steel pipe 7.

  The cooling device 2 installed on the downstream side (right side in FIG. 1) of the high-frequency heating device 1 with respect to the conveyance direction A of the steel pipe 7 is a jacket 8 as a support surrounding the conveyance path C of the steel pipe 7 as shown in FIG. And a water supply device 9 as a coolant supply means for supplying coolant, in this embodiment, coolant, in the inside of the jacket 8. A plurality of nozzles (i.e., cooling water discharge units) 11 are provided side by side on the inner surface of the jacket 8 that faces the conveyance path C of the steel pipe 7.

  The jacket 8 has an internal space surrounding the conveyance path C of the steel pipe 7, and the cooling water supplied to the internal space of the jacket 8 is conveyed from the plurality of nozzles 11 by a predetermined pressure to the conveyance path of the steel pipe 7. Released towards C. The cooling water thus discharged strikes the steel pipe 7 (that is, comes into contact with it) and instantaneously lowers the outer surface of the steel pipe 7 to the temperature of the cooling water, thereby quenching the steel pipe 7. The time required to lower the entire steel pipe to near the cooling water temperature is about 1.4 seconds from a general heat conductivity calculation. The cooling water after cooling the steel pipe 7 is collected into the water supply device 9 and again subjected to the cooling process. A filter for removing dust, dust and the like is provided in the cooling water recovery path as necessary.

  In this embodiment, the nozzles 11 are provided at four different positions (a), (b), (c), and (d) along the conveying direction A of the steel pipe 7. At each position, as shown in FIGS. 3A to 3D, eight nozzles 11 are provided in the circumferential direction. Nozzles 11 at positions adjacent to each other in the conveying direction A of the steel pipe 7, for example, the circles of the nozzles 11 in FIGS. 3 (a) and (b), (b) and (c), and (c) and (d). The installation positions along the circumferential direction are angularly shifted from each other. In the present embodiment, the installation angle is 45 ° / 2 = 22.5 ° between the positions (a) and (b), (b) and (c), and (c) and (d) in FIG. Is shifted.

  Each nozzle 11 is configured as shown in FIGS. 4B is a cross-sectional view of the entire nozzle 11, FIG. 4A is a cross-sectional view seen from the side to which the cooling water is supplied, and FIG. 4C is the side from which the cooling water is discharged. It is the end view seen from. As shown in these drawings, the nozzle 11 is formed by fitting a spiral-shaped member 15 into a cylindrical outer tube 14. The outer tube 14 and the helical member 15 are made of metal. The helical member 15 is fixed to the outer tube 14 so as not to rotate.

  The spiral-shaped member 15 is formed by twisting a core material 31 as shown in FIG. 5 as indicated by an arrow J around its own central axis X0. The core material 31 is formed of a quadrangular column-shaped metal material having a substantially square cross section, and has four rectangular side surfaces 32. A groove 33 having a quadrangular cross section is formed in the center of the side surface 32 along the axis X0. The cross-sectional shape of the groove is not limited to a square, and may be a triangle, a circle, an ellipse, or an ellipse.

  By twisting the core material 31, both the side surface 32 and the groove 33 are bent in a spiral shape about the axis X0. A surface formed by bending the side surface 32 in a spiral shape is a spiral surface, and a groove formed by bending the groove 33 in a spiral shape is a spiral groove. In the present embodiment, the side surface 32 is a predetermined spiral surface, that is, a surface that is twisted to become a spiral surface.

  The outer edge line of the spiral surface formed by twisting the side surface 32 corresponds to the spiral line formed by twisting the outer edge line 32a of the side surface 32 of the core member 31 in FIG. The angle θ1 formed by the spiral line with the central axis line X1 of the spiral-shaped member 15 in FIG. 4, that is, the central axis line X1 of the nozzle 11, is referred to as the spiral angle of the spiral surface. Further, an angle θ2 formed by an outer edge line of the spiral groove formed by twisting the groove 33 and the central axis X1 of the nozzle 11 is referred to as a spiral angle of the spiral groove.

  A small-diameter hole 12 for discharging cooling water is provided as an outlet hole in the center of the wall on the cooling water outlet side of the jacket tube 14. The diameter of the outlet hole 12 is, for example, φ2.0 mm. On the cooling water inlet side of the jacket tube 14, a large-diameter hole 13 is provided as an inlet hole for taking in the cooling water. The cooling water taken from the inlet hole 13 under a predetermined pressure is between the spiral surface of the spiral-shaped member 15 and the inner peripheral surface of the jacket tube 14 and between the spiral groove of the spiral-shaped member 15 and the jacket tube 14. When flowing between the inner peripheral surfaces, a spiral motion, that is, rotational energy is applied, and then, it is discharged from the outlet hole 12 to the outside. Due to this spiral motion, the cooling water is discharged from the outlet hole 12 while spreading in a cone shape, specifically a conical shape at a radiation angle α.

  The outer peripheral edge of the spiral-shaped member 15, that is, the outer edge line of the spiral surface (that is, the line in which the outer edge line 32 a in FIG. 5 is twisted) may be in contact with the inner peripheral surface of the jacket tube 14. There may be no gap between them. The setting of whether or not the outer peripheral line of the spiral surface is in contact with the inner peripheral surface of the jacket tube 14, the setting of the spiral angle θ1 of the spiral surface and the spiral angle θ2 of the spiral groove, and the spiral-shaped member 15 The length L is set according to how large the discharge angle α of the cooling water discharged from the outlet hole 12 is, or whether the cooling water is distributed within the entire angle range of the discharge angle α. Alternatively, the discharge angle α is appropriately set according to desired conditions such as whether or not to discharge the cooling water within a predetermined angle range of the central portion. In this embodiment, the discharge angle α = 30 °, and the cooling water is distributed in all angle regions within the α angle.

  If the spiral angle θ1 of the spiral surface or the spiral angle θ2 of the spiral groove is too large, or if the length L of the spiral-shaped member 15 is too long, as shown in FIG. There is a case where a blank area Y1 is generated in the central portion and an area (shaded area) Y2 where the cooling water hits is formed in an annular shape around the area. In this case, there is a possibility that the cooling is insufficient in the central portion where the cooling water does not spread. At this time, by reducing the spiral angle θ1 or θ2, or by shortening the length L of the spiral-shaped member 15, the entire region including the central portion in the cross section as shown by the oblique lines in FIG. Cooling water can be dispersed in (Y2), and as a result, efficient cooling treatment can be performed.

  In some cases, it may be desired to intentionally generate a region Y1 that is not exposed to cooling water. In such a case, the state can be realized by appropriately adjusting the spiral angle θ1 of the spiral surface, the spiral angle θ2 of the spiral groove, and the length L of the spiral-shaped member 15. Moreover, the discharge state of the cooling water can be changed by appropriately changing the cross-sectional shape or cross-sectional area of the spiral groove.

  In FIG. 2, the inner peripheral surface of the jacket 8 where the nozzle 11 is provided changes in a conical shape so that the diameter on the upstream side is small and the diameter on the downstream side is large in the transport direction A of the steel pipe 7. Yes. That is, the inner peripheral surface of the jacket 8 is inclined in a direction away from the conveyance path of the steel pipe 7 toward the downstream side in the conveyance direction A. For this reason, the cooling water discharged from each nozzle 11 is reliably discharged outside the jacket 8 without staying between the steel pipe 7 and the jacket 8.

  Further, since the inner peripheral surface of the jacket 8 spreads out in a conical shape, the area of the contact surface of the cooling water that comes out conically from each of the plurality of nozzles 11 and hits the steel pipe 7 is in the conveying direction A of the steel pipe 7. It increases from the upstream side toward the downstream side. Further, the plurality of nozzles 11 are provided at four different positions (a), (b), (c), and (d) along the conveying direction A of the steel pipe 7. Further, regarding the plurality of nozzles 11 placed at positions adjacent to each other along the transport direction A, in FIG. 3, (a) and (b), (b) and (c), (c) and (d ), The angular position along the circumferential direction of the steel pipe 7 is shifted by 22.5 °.

  Accordingly, when the portion of the steel pipe 7 that is exposed to the cooling water is developed as shown in FIG. 7, the surface of the steel pipe 7 is respectively corresponding to the positions (a), (b), (c), and (d). (A1), (b1), (c1), and a contact surface of cooling water is formed in each position of (d1). Actually, the shape of each contact surface is not a perfect circle but an ellipse or an ellipse because the inner peripheral surface of the jacket 8 is inclined, but is approximately displayed as a circle.

  As shown in FIG. 7, the contact surface of the cooling water gradually increases in accordance with the conveying direction A of the steel pipe 7. In this embodiment, the contact diameter of the most upstream contact surface is φa = 12 mm, and the contact diameters φb, φc, and φd on the downstream side are φb = 13 mm, φc = 16 mm, and φd = 20 mm, respectively. there were. Since the flow rate of the cooling water ejected from each nozzle 11 is the same, the flow rate density of the cooling water is high on the upstream side where the area of the contact surface is small, and the flow rate density decreases toward the downstream side. As a result, the steel pipe 7 entering the jacket 8 at a high temperature can be initially poured with high-density cooling water. Further, after the temperature of the steel pipe 7 has dropped to some extent, the low-density cooling water is widened to the steel pipe 7. Can take a long time in range. Thus, the steel pipe 7 can be efficiently cooled with a small amount of cooling water.

  Further, in FIG. 2, a plurality of nozzles 11 placed at positions adjacent to each other along the transport direction A, that is, (a) and (b), (b) and (c), (c) and (d). With respect to the group (eight) nozzles 11 placed at the respective adjacent positions, as shown in FIG. 3, there is a group of nozzles 11 at one position and another group of nozzles 11 at the other position. The angular position along the circumferential direction is shifted by 22.5 °.

  For this reason, in FIG. 7, between adjacent cooling water contact surfaces, that is, between (a1) and (b1), between (b1) and (c1), and between (c1) and (d1). Thus, the position of the contact surface is shifted in the circumferential direction (in the drawing, the direction orthogonal to the conveyance direction A). Specifically, the center point of one contact surface is shifted so as to coincide with the midpoint between the center points of two adjacent contact surfaces in the circumferential direction. As a result, the interval along the conveyance direction A of each contact surface at different positions (a1), (b1), (c1), and (d1) along the conveyance direction A is reduced, that is, the distribution density of the contact surface is reduced. As a result, the steel pipe 7 can be efficiently cooled.

This will be described with reference to the drawings.
In FIG. 7, the positions (a1), which are the outer two of the cooling water contact surfaces at different positions (a1), (b1), (c1), (d1) along the steel pipe conveying direction A, and Consider a line BB, which is a line connecting the centers of the contact surfaces at the position (d1). Along the BB line, the contact surfaces at the positions (a1), (b1), (c1), and (d1) are drawn as shown in FIG.

  In the present embodiment, the diameter φa of the contact surface at the position (a1) is 12 mm, the diameter φb of the contact surface at the position (b1) is 13 mm, the diameter φc of the contact surface at the position (c1) is 16 mm, The diameter φd of the contact surface at the position (d1) was 20 mm.

The areas of the cooling water that directly hits the surface of the steel pipe 7 are separated from each other as shown in FIG. In the present embodiment, the distances k1, k2, and k3 between the contact surfaces are respectively
k1 = 1.62mm, k2 = 1.55mm, k3 = 2.22mm
Met. However, in the actual cooling process, when cooling water is directly applied to the surface of the steel pipe 7, there is a substantial cooling area that is a radial cooling area centering on the contact surface of the cooling water due to heat conduction. The actual cooling area for each contact surface is indicated by symbols Ma, Mb, Mc, and Md in FIGS. 8B and 8C.

  As can be seen from FIG. 8C, the steel pipe 7 is cooled by the cooling water in all cross-sectional portions due to the existence of the substantial cooling areas Ma, Mb, Mc, and Md. That is, the actual cooling area ratio is 100%, and it can be seen that highly efficient cooling is performed.

(Cooling capacity of nozzle 11)
Since the nozzle 11 is inclined with respect to the conveyance path C of the steel pipe 7, an elliptical cooling water contact surface is formed on the surface of the steel pipe 7 instead of a perfect circle. However, in the following discussion, the calculation is performed assuming that the cooling water contact surface is circular. Further, the substantial outer diameter of the contact surface of the cooling water is set to (the contact diameter + 4 mm) with respect to each contact diameter φa, φb, φc, φd.

(A) If the surface area of the portion of the steel pipe 7 cooled by the cooling water is SA7, this is the area of the steel pipe surface portion 7 shown in FIG.
SA7 = (outer diameter of steel pipe 7) × π × (length La along conveyance direction A)
= 31.8 × π × 63.9
= 6380mm ²
It is.

(A) When the cooling area by the cooling water passing through the nozzle 11 provided in the jacket 8 is RA11,
RA11
= [{(Per diameter φa + 4) / 2} ² × π × number] + [{(per diameter φb + 4) / 2} ² × π × number] + [{(per diameter φc + 4) / 2} ² × π × number ] + [{(Per diameter φd + 4) / 2} ² × π × number]
= [{(12 + 4) / 2} ² × π × 8] + [{(13 + 4) / 2} ² × π × 8] + [{(16 + 4) / 2} ² × π × 8] + [{(20 + 4 ) / 2} ² × π × 8]
= 1607 + 1814 + 2512 + 3617
= 9550mm ²
It is.

(C) From the above, the cooling area ratio RAR11 for the steel pipe 7 by the plurality of nozzles 11 is:
RAR11 = cooling area (RA11) / steel pipe cooling surface area (SA7)
= 9550/6380
= 1.496
It is. Thus, according to the present embodiment, the cooling area ratio exceeds 100%.

(Overall flow rate of cooling water required to solve the vapor film problem)
As described in the “general description of the cooling device” column (A), the “cooling water flow velocity and flow rate for facing the vapor film” column (f), the vapor film is formed on the surface of the workpiece in the general cooling device. When the water pressure is 3 kg / cm ² , the flow rate of the cooling water required to prevent generation of water or break through the vapor film is 3 L / min for one hole for cooling water injection.
Therefore, in the cooling device of FIG. 2, the total flow rate FR2 of the cooling water necessary for not generating or breaking through the steam pipe around the steel pipe 7 is
FR2 = flow rate x number of holes
= 3L / min × 32
= 96L / min ... (F2)
It is.

(Overall flow rate of cooling water required to solve the vapor film problem)
In the conventional cooling device 52 shown in FIG. 11, the total flow rate FR52 of the cooling water necessary for generating no steam film around the steel pipe 57 or breaking through the steam film is obtained by the above formula (F1).
FR52 = 576L / min
Met. Further, in the cooling device 2 of FIG. 2, the total flow rate FR2 of the cooling water that is not generated around the steel pipe 7 or breaks through the vapor film is obtained by the above formula (F2).
FR2 = 96L / min
It is.
That is, according to the cooling device 2 of the present embodiment, the flow rate of the cooling water that can obtain a good quenching state can be significantly reduced as compared with the conventional cooling device 52.

(Other embodiments)
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made within the scope of the invention described in the claims.
For example, in the embodiment of FIG. 2, the present invention is applied to an induction hardening apparatus using the induction heating apparatus 1, but the present invention can also be applied to a hardening apparatus other than the induction hardening apparatus. The present invention can also be applied when performing a heat treatment other than quenching such as annealing.

  In the above embodiment, the jacket 8 is fixed and the steel pipe 7 is moved in FIG. However, the steel pipe 7 may be arranged in a fixed state and the jacket 8 may be moved.

  In the embodiment of FIG. 2, a plurality of nozzles 11 are provided at four locations (a), (b), (c), and (d) along the conveyance direction A of the steel pipe 7, but the installation locations of the nozzles 11 are three locations. It is good also below or 5 places or more.

  In the said embodiment, as shown in FIG. 3, the arrangement | positioning angle position of the nozzle 11 in the circumferential direction of the steel pipe 7 is set to the arrangement position (a), (b), (c) along the conveyance direction A of the steel pipe 7. , (D). However, the positions of the plurality of nozzles 11 may be the same among the different positions (a), (b), (c), and (d) along the transport direction A without shifting the installation angle positions.

  In the above embodiment, room temperature water is used as the coolant. However, the cooling liquid may be an appropriate liquid other than water.

  In the above embodiment, as shown in FIG. 5, the side surface 32 of the quadrangular prism core material 31 is set as a planned spiral surface, the groove 33 is provided on this surface, and these surfaces are twisted to form a spiral surface. Then, a spiral groove 15 was formed to form a spiral member 15, and the spiral member 15 was accommodated in the jacket tube 14 as shown in FIG. Instead of this configuration, as shown in FIG. 9 (a), a flat surface 16 is formed as a planned spiral surface on the side surface of a cylindrical rod-shaped core member, and this is twisted to form a spiral surface to form a spiral member. And this helical member can be housed in the jacket tube 14 as shown in FIG.

  Further, as shown in FIG. 9 (b), the four outer peripheral surfaces 17 of the rectangular columnar bar are set as the spiral planned surfaces, and these surfaces are twisted to form a spiral surface, thereby producing a spiral-shaped member 15. In addition, the helical member can be accommodated in the jacket tube 14 as shown in FIG. Further, as shown in FIG. 9 (c), four curved surfaces 18 that curve toward the central axis X0 of the core material are set as planned spiral surfaces, and these surfaces are twisted to form a spiral surface to form a spiral. The shape member 15 can be produced, and this spiral shape member can be accommodated in the jacket tube 14 as shown in FIG.

  Furthermore, as shown in FIG. 9 (d), two curved surfaces 19 that are curved toward the central axis X0 of the core material are set as the predetermined spiral surfaces, and these surfaces are twisted. It is also possible to form a spiral surface by forming a spiral surface 15 and store the spiral shape member in the jacket tube 14 as shown in FIG.

1. 1. a high-frequency heating device; 6. cooling device; Steel pipe (object), 8. Jacket (support), 9. 10. Water supply device (coolant supply means) Nozzle, 12. Exit hole, 13. Inlet hole, 14. 15. jacket tube, A helical member, 16. Plane (spiral plane), 17. 17. Outer peripheral surface (spiral planned surface) 18. Curved surface (spiral plane), 21. Curved surface (spiral planned surface) Induction hardening equipment, 22. Steel pipe rapid feed mechanism (steel pipe conveying device), 23. Steel pipe transport mechanism (steel pipe transport device), 24a, 24b, 24c. Steel pipe rotation mechanism, 28. Dispensing mechanism 31. Core material, 32. Side surface (spiral plane), 32a. Outer edge line (outer rim), 33. A spiral groove, A. Steel pipe transport direction, φa, φb, φc, φd. Cooling water contact diameter, (a1), (b1), (c1), (d1). Location of cooling water on the surface of the steel pipe, La. The length of the cooling direction of the steel pipe in the conveying direction, Lb. The circumferential length of the cooling region of the steel pipe, θ1. The helical angle of the helical surface, θ2. Groove spiral angle, α. Cooling water discharge angle, Y1. Area where cooling water does not hit, Y2. Region where cooling water hits, Ma, Mb, Mc, Md. The actual cooling area of the cooling water, k1, k2, k3. Distance between adjacent contact surfaces of cooling water

Claims (12)

In a cooling device that cools an object by bringing a coolant into contact with the heated object,
A support that is movable relative to the object and supports a plurality of nozzles on a surface facing the object;
A coolant supply means for supplying the coolant to the plurality of nozzles,
At least one of the plurality of nozzles is
An outer tube having a space inside, an outlet hole for discharging the cooling liquid at the tip, and an inlet hole for receiving the cooling liquid at the other end;
A spiral-shaped member provided inside the jacket tube,
At least one spiral surface which is a spiral surface is provided on the outer peripheral surface of the spiral-shaped member, and the spiral surface is opposed to the inner peripheral surface of the jacket tube,
The diameter of the outlet hole is smaller than the outer diameter of the helical member,
The cooling liquid supplied by the cooling liquid supply means enters the inside of the jacket pipe through the inlet hole, flows along the spiral surface, and then spreads out in a conical shape from the outlet hole. A cooling device characterized by.   The cooling device according to claim 1, wherein an outer peripheral edge of the spiral-shaped member is in contact with an inner peripheral surface of the outer tube.   3. The spiral member according to claim 1, wherein the spiral member is a rod-like member, and has a plurality of spiral surfaces arranged in a circumferential direction around the central axis of the spiral member on the outer peripheral surface thereof. Cooling system.   The cooling device according to claim 1, wherein the spiral surface is a flat plane.   The cooling device according to any one of claims 1 to 3, wherein the spiral surface is a curved surface that is curved toward a central axis of the spiral-shaped member.   The cooling device according to claim 1, wherein a groove is provided in the surface of the spiral surface.   The spiral angle of the spiral surface is a spiral angle capable of distributing the coolant over the entire surface from the center point to the outer peripheral edge of the coolant contact surface on the surface of the object. The cooling device according to claim 6.   The spiral-shaped member has a rod-shaped core material, and at least one planned spiral surface extending in the direction of the central axis of the core material is formed on the outer peripheral surface of the core material before the twisting process. The cooling device according to any one of claims 1 to 7, wherein the predetermined spiral surface is formed on the spiral surface by performing a twisting process centering on the central axis.   The cooling device according to any one of claims 1 to 8, wherein the plurality of nozzles are provided at different positions along a moving direction of the object with respect to the support.   The plurality of nozzles are provided at different angular positions around a moving path of the object in a plane perpendicular to a moving direction of the object with respect to the support. Item 10. The cooling device according to any one of Items 9. The plurality of nozzles are provided at different positions along the moving direction of the object relative to the support,
The plurality of nozzles are provided at different angular positions around the moving path of the object in a plane perpendicular to the moving direction of the object with respect to the support,
The plurality of nozzles that are adjacent to each other along a moving direction of the object with respect to the support are arranged so as to be shifted from each other with respect to an angular position about a moving path of the object. The cooling device according to any one of claims 1 to 10.   12. The object according to claim 1, wherein the object is a heated steel pipe, and the coolant is water at room temperature or lower, which is a normal temperature that is not heated and cooled. Cooling system.

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