JP2002294341A - Cooling device used for heat treatment, and heat treatment device provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and reliably quench only a part of a work without using any special die. SOLUTION: A main pipe 34 vertically inserted between a large number of cam shafts which are positioned and loaded on a heat treatment pallet and branch pipes 35 provided on the main pipe 34 at equal intervals are provided, the branch pipes 35 are disposed parallel to the cam shafts, air jetting holes 36a and 36b opened in each branch pipe 35 are arranged so as to jet air to the entire circumference of the cam parts, and the area of air feed holes 60b-60h for feeding air to each branch pipe 35 is reduced toward the forward end of the main pipe 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device used for heat treatment and a heat treatment device provided with the cooling device.

[0002]

2. Description of the Related Art In order to improve the wear resistance of a work as a cast product, a part of the work may be rapidly cooled to form a chill layer. As a conventional example of a method of rapidly cooling only a part of a work in order to form a chill layer, see Japanese Patent Laid-Open No. 1-130.
There is a method described in JP-A-838 and JP-A-9-155518. First, Japanese Unexamined Patent Publication No. 1-130838 discloses a casting method in which only a part of a camshaft of an engine is rapidly cooled during casting. This casting method uses a copper-based alloy having a high thermal conductivity for the mold body, allows cooling water to flow through the mold, and quenches the molten metal in the copper-based alloy mold, thereby reducing the camshaft cam. It promotes the chilling of the part. On the other hand, in the journal portion that does not require chilling, a nest having a low thermal conductivity is arranged inside the mold body and is gradually cooled. Also, Japanese Patent Application Laid-Open No. 9-155518 discloses a casting method in which a camshaft is cast using a mold having a plurality of split molds, and only a part of the casting is rapidly cooled. The split mold is configured to be able to be opened independently, and the split mold corresponding to the journal portion is opened earlier than the split mold cast on the cam portion. As a result, the journal portion is gradually cooled by the atmosphere, but the cam portion is rapidly cooled by the split mold.

[0003]

However, cooling by the casting method disclosed in Japanese Patent Application Laid-Open No. 1-130838 and cooling by the casting method disclosed in Japanese Patent Application Laid-Open No. 9-155518 are complicated metallurgy. To use the mold,
Costs were high and work efficiency was poor. Further, in cooling by contact with cooling water or a mold, since the boundary between the region to be rapidly cooled and the region to be gradually cooled cannot be clearly separated, the journal portion is often chilled, and only the predetermined portion is surely formed. Could not cool. In both methods, since the casting mold is used for cooling, new casting cannot be performed during the formation of the chill layer, the cycle time of the casting process becomes longer, and work efficiency is increased. There was a problem of lowering. Therefore, the present invention, when rapidly cooling only a part of the work, without using a special mold, efficiently,
The purpose is to ensure cooling.

[0004]

According to a first aspect of the present invention, there is provided a cooling apparatus having air ejection means for injecting air to a high-temperature work to cool the work. The means has a main pipe through which air flows, and the main pipe is provided with air supply holes through which air flows out at equal intervals along the longitudinal direction thereof, and the air supply hole has
A cooling device used for heat treatment having an arrangement in which the opening area decreases from one end side, which is the air supply source side, to the other end side. This cooling device has an arrangement in which the opening area of each air supply hole is reduced from one end side to the other end side when the air ejection means for ejecting air to the work has a plurality of air supply holes. By making the outflow amount of air from the air supply hole substantially constant, the cooling effect of the work is made uniform.

According to a second aspect of the present invention, there is provided a cooling device used for the heat treatment according to the first aspect,
The air jetting means has a branch pipe communicating with the air supply hole, and the branch pipe has an air jet hole for jetting air from a different angle to a predetermined portion of the work. This cooling device blows air from a plurality of air ejection holes provided in a plurality of branch pipes to a predetermined portion of a work, and air is blown from a different angle to one of the predetermined portions of the work. It becomes possible to spray.

[0006] Further, the invention according to claim 3 of the present invention provides:
In the cooling device used for the heat treatment according to claim 1 or 2, the air ejection hole ejects air from a different angle to a center position of a predetermined portion of the work,
The configuration has a hole diameter corresponding to the area of the predetermined portion.
This cooling device uniformly cools even if there are a large number of predetermined portions to be cooled by blowing air onto the work and the predetermined portions have different areas. Specifically, an air ejection hole that blows air to a predetermined portion having a large area has a large hole diameter (opening area), and an air ejection hole that blows air to a predetermined portion having a small area has a small hole diameter (opening area).

The invention according to claim 4 of the present invention provides:
The heat treatment furnace according to any one of claims 1 to 3, wherein the heat treatment furnace heats the work, transport means for carrying the work into and out of the heat treatment furnace, and the heat treatment furnace is configured to be able to move forward and backward with respect to the heated work. And a cooling device used for the heat treatment. In this heat treatment apparatus, only a predetermined portion of a workpiece heated in a heat treatment furnace is rapidly and surely cooled.

[0008]

Embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a camshaft W which is a work cast by the mold 1 shown in FIG.
After heating and keeping the temperature in the heat treatment apparatus 2 shown in FIG. 1, only a part thereof is rapidly cooled to form a chill layer.

First, the mold 1 for casting the camshaft W will be described. The mold 1 is a two-part mold, and FIG. 1 shows only one mold in an opened state. This mold 1 has two cavities 3 for casting two camshafts W at the same time. A hot water supply port 4 for injecting the molten metal into each cavity 3 is formed at the center of the mold 1, and a runner 5 is formed between the hot water supply port 4 and one end (the lower end in FIG. 1) of each cavity 3. ing. At the other end (upper end in FIG. 1) of the cavity 3, a hook portion 6 and a rising portion 7 are provided. In the mold 1, a plurality of cooling water passages 8 are provided around the cavity 3 corresponding to the cam portion C of the camshaft W, but the cooling water passages 8 are not essential components. The structure of the mold 1 shown in FIG. 1 is an example, and a mold having any other structure can be used.

[0010] Here, the camshaft W as a work is
As shown in FIG. 1, a plurality of cam portions C and journal portions J are arranged along the longitudinal direction of the shaft axis A. In the present embodiment, only the cam portion C is rapidly cooled, and other portions are not rapidly cooled. The reason for this is that the cam portion C is required to have a high abrasion resistance, so that it is necessary to form and harden a chill layer. On the other hand, the journal portion J needs to be cut to increase the rotational accuracy of the camshaft W, and the shaft axis A is required to have toughness in order to extend the life of the camshaft W. Note that the cam portion C corresponds to a predetermined portion described in the claims.

Next, the structure of the heat treatment apparatus 2 for heat treating the camshaft W cast by the mold 1 will be described. As shown in FIG. 2, the heat treatment apparatus 2 includes a heat treatment furnace 10 that can process a large number of camshafts W at one time, a roller conveyor 11 that is a conveyance unit that conveys and unloads the camshafts W to and from the heat treatment furnace 10, and a heat treatment furnace. The cooling device 12 is disposed on the outlet side 10a of the furnace 10 and rapidly cools the cam portion C of the camshaft W after the heat treatment. In addition, many camshafts W are placed on the heat treatment pallet 13 and processed.

The heat treatment furnace 10 includes a plurality of heat treatment pallets 1
3 is a furnace that can hold a plurality of camshafts W at a high temperature of about 1000 ° C., and is a known furnace such as a gas furnace. The heat treatment furnace 10 has a configuration capable of performing heat treatment in an inert gas atmosphere or a reducing gas atmosphere.
It is desirable that the temperature gradient at the time of temperature rise or temperature fall can be controlled.

The roller conveyor 11 is a first roller conveyor 11 for carrying the heat treatment pallet 13 into the heat treatment furnace 10.
a, and a second roller conveyor 11b for carrying out the heat-treated pallet 13 after the heat treatment. Further, rollers and the like (not shown) are also provided in the heat treatment furnace 10.
The movement of the heat treatment pallet 13 within 0 is enabled. Note that these roller conveyors may be laid as one roller conveyor.

Next, the heat treatment pallet 13 will be described. 3 is a plan view of the heat treatment pallet, FIG. 4 is a front view of the heat treatment pallet, and FIG. 5 is a side view of the heat treatment pallet. The heat treatment pallet 13 includes mounting plates 23a, 23b in which columns 22a, 22b, 22c arranged in the left-right direction from the base 21 are arranged in three rows in the front-rear direction, and are stacked by inserting the columns 22a to 22c. I have.

As shown in FIGS. 4 and 6 (a) and 6 (b), the mounting plate 23a is
It comprises a tube portion 24 and a tube portion 25 through which the 2a and the support 22b are inserted, respectively, and a plate 26 connecting the tube portions 24 and 25. The cylindrical portion 24 is a hollow member having the same height as the plate 26, and the cylindrical portion 25 has a half height of the plate 26. The cylindrical portion 24 is provided at one end of the plate 26,
The cylindrical portion 25 is fixed below the other end of the plate 26. Further, the plate 26 has two notches 27 each of which is cut out in a substantially V-shape so as to be vertically aligned, and as shown in FIGS.
Are stacked, the notch 27 formed above the plate 26 of the lower mounting plate 23a and the notch 27 formed below the plate 26 of the upper mounting plate 23a have a substantially rhombic shape. Is formed. This opening serves as a holding portion 41 for positioning and holding the shaft axis A of the camshaft W.

As shown in FIGS. 4 and 7 (a) and 7 (b), the mounting plate 23b has a cylindrical portion 28 and a cylindrical portion 29 through which the columns 22b and 22c, which are erected at long intervals, are respectively inserted. And a plate 30 connecting the cylindrical portions 28 and 29
Consists of The cylindrical portion 28 is a hollow member having half the height of the plate 30. On the other hand, the cylindrical portion 29 is
It is a hollow member having the same height as the height. Tube part 2
Reference numeral 8 denotes an upper portion of one end of the plate 30, and the cylindrical portion 29 is fixed to the other end of the plate 30. Further, the plate 30 has three notches 27, each of which is cut out in a substantially V-shape so as to be aligned vertically, as shown in FIGS.
When the mounting plate 23b is stacked on the column 22 as shown in FIG. 7, the notch 27 forms a substantially rhombic opening in the same manner as described above, and becomes the grip portion 41 for positioning and gripping the shaft axis A of the camshaft W. .

When the mounting plate 23a and the mounting plate 23b are stacked, the mounting plate 23a and the mounting plate 23b are alternately inserted into the columns 22b. As a result, in the column 22b of FIG. 4, the cylindrical portions 25 and the cylindrical portions 28 having half the height are alternately arranged.
In addition, the grip portions 41 formed at this time are arranged at equal intervals in the horizontal direction, and five portions are arranged in FIG. This is because each camshaft W is controlled by the cooling device 12 described in detail later.
This is for uniformly and rapidly cooling the entire circumference of the cam portion C. Therefore, the notches 27 of the mounting plate 23a and the mounting plate 23b are formed at the same pitch, and the notch 27 at the other end of the mounting plate 23a and the notch 27 at one end of the mounting plate 23b are also supported by the support 22b. Are formed at positions having the same pitch.

As shown in FIGS. 3 and 5, the heat treatment pallet 13 is provided with
3b are stacked in three rows in the front-rear direction, and one camshaft W is positioned and gripped by three grippers 41 arranged side by side in the front-rear direction. That is, the camshaft W is positioned and gripped so that its longitudinal direction coincides with the moving direction of the heat treatment pallet 13, and each heat treatment pallet 13 has five camshafts W in the horizontal direction.
, Ie, 35 camshafts W are placed on one heat treatment pallet 13. In the present embodiment, the shape of the cutout portion 27 is a right-angled isosceles triangle, and the shape of the grip portion 41 is a square.

Next, the cooling device 12 will be described. 9 is a front view of the cooling device, FIG. 10 is a side view of the cooling device, and FIGS. 11A and 11B are diagrams illustrating the relationship between the cooling device and the heat treatment pallet. As shown in FIG. 2 and FIG. 11A, the cooling device 12 is provided on the outlet side 10 of the heat treatment furnace 10.
5A, it is located above the second roller conveyor 11b, and is arranged to be able to move up and down by a known elevating mechanism (not shown). The cooling device 12 is provided with an air ejection means 32 for ejecting air to the cam portion C of the heated camshaft W to cool rapidly on a lower surface of the main body portion 31 having a rectangular parallelepiped shape. Air pipes 33 for supplying air to the air jetting means 32 are connected to the left and right surfaces of the main body 31.

As shown in FIGS. 9 and 10, the air jetting means 32 is provided vertically downward from the lower surface of the main body 31, and has a main pipe 34 extending vertically downward from the lower surface.
And a short branch pipe 35 projecting horizontally from a predetermined position of the main pipe 34. As shown in FIGS. 12A and 12B, the shape of the main pipe 34 is a bottomed square prism having a main flow path 51 through which air flows. Open end 52 at the top of main pipe 34
Is formed with a flange 53.
Is bolted to the main body 31 of the cooling device 12. Further, the main pipe 34 is provided on a pair of opposed side faces 34 a of the main pipe 34.
The insertion holes 54 into which the supply pipes 57 having the air supply holes 60a to 60h for controlling the amount of air to be ejected from are inserted are formed at equal intervals.

As shown in FIG. 9, the main pipe 34 is
Are arranged at regular intervals in the left-right direction of the lower surface of the. Further, as shown in FIG. 10, the main pipe 34 has two rows in the front-rear direction. Accordingly, the cooling device 12 as a whole has 12 main tubes 34 extending therefrom. The main pipes 34 are arranged at equal intervals in the left-right direction because the cooling device 12
As shown in FIG. 11 (b), when two camshafts descend from the upper position shown in FIG. 11 (a) with respect to the heat-treated pallet 13 after the heat treatment, as shown in FIG. This is for inserting the main pipe 34 between W. That is, the extension pitch of the main pipe 34 is the same as the formation pitch of the cutout portions 27 of the mounting plates 23 a and 23 b of the heat treatment pallet 13, and the extension position of the main pipe 34 is half of the formation position of the cutout portion 27. It is shifted by the pitch. In FIG. 13, the main pipe 34 is inserted so as to be orthogonal to the shaft axis A of the camshaft W.

As shown in FIG. 12B, each supply pipe 57
Are provided with air supply holes 60a to 60h for communicating the main flow path 51 and the cylindrical member 55. The remaining air supply holes 60b to 60g excluding the air supply hole 60h of the branch pipe 35B and the air supply hole 60a of the branch pipe 35T are from the upper side to the lower side, that is, the open end 5 which is one end close to the air supply source.
The diameter (opening cross-sectional area) decreases from 2 to the bottomed portion at the other end. This is because each cylindrical member 55 (branch 3
By equalizing the amount of air per unit time supplied to 5), the air ejection holes 36a and 36b of each cylindrical member 55 are formed.
The amount of air blown out from each cam section
Is to be rapidly cooled evenly regardless of the location. Since the air ejected from the air ejection holes 36a and 36b has a predetermined angle, the air ejected from the four branch pipes 35 toward one cam portion C is applied to the entire circumference of the cam portion C. Sprayed.

The branch pipe 35 is a side pipe 34a of one main pipe 34.
Are arranged at equal intervals. When the cooling device 12 is lowered and the main pipe 34 is inserted between the camshafts W, the branch pipes 35 are arranged at the vertical center positions of the mounting plates 23a and 23b as shown in FIG. Further, it is disposed so as to be parallel to the shaft axis A of the camshaft W. Thereby, as shown in FIG. 14, when the main pipe 34 is inserted between the adjacent camshafts W, the four branch pipes 35 adjacent in the vertical and horizontal directions are provided.
Are located at the center of a quadrangle having each apex as the cam portion C (the rotation center axis of the shaft axis A).

As shown in FIGS. 15A and 15B, the branch pipe 35 is fixed to a bottomed cylindrical member 55 and an open end of the cylindrical member 55, and is a fixing plate used for fixing to the main pipe 34. 56. The fixing plate 56 has an opening, and the supply pipe 57 is inserted through the opening.

In the cylindrical member 55, a small-diameter air ejection hole 36a for ejecting air toward the cam portion C and a large-diameter air ejection hole 36b are formed so that the width of each cam portion C in the axial direction is ２. It is formed at a position, that is, a position corresponding to the center of the cam portion C in the width direction. This air ejection hole 36a,
36b has a hole diameter corresponding to the size of the area in the circumferential direction of each cam portion C, and is bored in upper and lower two rows, and the drilling angle of the air supply holes 36a, 36b in the upper row 58 is: The elevation angle is 30 degrees with respect to the rotation center axis of the cylindrical member 55, and the piercing angle of the air supply holes 36a and 36b in the lower row 59 is set at a depression angle of 30 degrees with respect to the rotation center axis of the cylinder member 55. Has become. By setting the drilling angles of the air supply holes 36a and 36b as described above, the camshaft W
At the time of cooling, four branch pipes 35 surrounding one cam portion C
Can be blown out toward the cam portion C (the rotation center axis of the shaft shaft A) from each of them, and can be blown over the entire circumference of the cam portion C (see FIG. 14). This allows the cam portion C to be uniformly rapidly cooled because air is blown from different angles.

In each of the rows 58 and 59, the diameter (opening area) of the air ejection hole 36b is set at the air ejection holes 36 at both ends.
The reason for being larger than “a” is that, as shown in FIG. 16, the cam portion C located at the center is wider than the cam portions C on both sides thereof, so that more air needs to be blown. In this manner, the air ejection holes 36a and 36 having different hole diameters correspond to the size (area in the circumferential direction) of the cam portion C.
By preparing b, it is possible to uniformly cool and chill it regardless of the size of the cam portion C. The piercing angle is determined by the position of the cam portion C of the camshaft W and the arrangement of the branch pipe 35, so that the piercing angle can be set to any angle. In the present embodiment, however, the piercing angle is 25 to 65 degrees. It is desirable to be within the range. In addition, each air ejection hole 36a,
It is desirable that the drilling angle of 36b is the same value,
Depending on the shape of the portion to be quenched, the piercing angle may be different for each location.

In FIG. 12 (b), only the lower row 59 of the branch pipe 35T located at the top (uppermost stage) is drilled. This is because the camshaft W is not mounted above the branch pipe 35T, so that it is not necessary to jet air. Similarly, the bottom (bottom)
, Only the upper row 58 is perforated. This is because the camshaft W is not mounted below the branch pipe 35B.

The branch pipe 35T has an air supply hole 60a.
Has only the lower row 59, it is desirable to make the diameter smaller than the air supply hole 60b below. In the present embodiment, the diameter of the air supply hole 60a is set to 11.3.
mm, and the diameter of the air supply hole 60b is φ16.0 mm.
Are reduced by 0.4 mm from the air supply holes 60b to 60f immediately above. The diameter of the lowermost air supply hole 60h is only 9.5 mm, which is significantly smaller than that of the other air supply holes because only the upper row 58 is provided.

Next, the steps of casting and heat-treating the camshaft W will be described. First, in order to cast the camshaft W, the mold 1 shown in FIG.
The molten metal is poured from the hot water supply port 4. The injected molten metal is runner 5
Is poured into each cavity 3 and the molten metal is solidified in the cavity 3 by natural cooling of the mold 1 and circulation of the cooling water,
The casting F is completed. The cast product F at this time is gray cast iron, but since the cam portion C and its vicinity are cooled more than other portions by the circulation of the cooling water, the solidification rate is higher and a hard chill layer is formed. The chill layer has a pearlite-rich structure, and the other portions have a relatively soft ferrite-rich structure. However, as described above, the boundary of the chilling during casting is not stable, and at this stage, the journal J is also partially chilled.

When the molten metal is solidified, the gripping device is moved to the hook portion 6.
To remove the casting F from the mold 1. Then, the non-product portion 40 including the hook portion 6 is cut by a cutting device, and the remaining product portion, that is, the camshaft W, is heat-treated in the next step.

Next, prior to the heat treatment step, the camshaft W is first placed on the heat treatment pallet 13. The heat treatment pallet 13 is on standby in a state where the columns 22 erecting from the base 21 have passed the mounting plates 23 a and 23 b by one stage. Here, the camshaft W after casting by a gripping means (not shown) or manually is placed on the mounting plates 23a, 23b.
Are placed one by one in each notch 27. When the camshaft W is placed on all of the notches 27 of the first-stage mounting plates 23a and 23b, the second-stage mounting plates 23a and 23b are inserted through the columns 22 as shown in FIG. At this time, the notch 2 on the lower side of the second stage mounting plates 23a and 23b
7 comes into contact with the upper side of the shaft axis A of the camshaft W, thereby positioning the camshaft W.
7. Thereafter, the same operation is performed, and the camshaft W is mounted.

The heat treatment pallet 13 on which the mounting of the camshaft W is completed is carried into the heat treatment furnace 10 by the first roller conveyor of FIG. At the entrance of the heat treatment furnace 10, the heat treatment pallet 13 is carried into the heat treatment furnace 10,
The heat treatment pallet 13 already heated in the heat treatment furnace 10 is extruded.

Then, in the heat treatment furnace 10 into which the new heat treatment pallet 13 is loaded, the camshaft W is tempered according to, for example, a time chart shown in FIG. The tempering in this case is performed by raising the temperature of the camshaft W to about 930 ° C. (TU) over about 30 minutes,
This is performed by holding 0 minutes (TS). Thereby, the composition of the camshaft W becomes austenite. Then, when the holding time ends, the camshaft W is carried out of the heat treatment furnace 10 together with the heat treatment pallet 13.

The heat treatment pallet 13 carried out of the heat treatment furnace 10 is stopped by a stopper (not shown). And
When the heat treatment pallet 13 stops, the main body 31 of the cooling device 12 that has been waiting at the upper position is lowered, and the main pipe 34 is inserted between the camshafts W adjacent in the horizontal direction as shown in FIG. At this time, the branch pipe 35 disposed on the main pipe 34 is located between the camshafts W in the vertical direction.
Further, the air ejection holes 36a and 36b of the branch pipe 35 are positioned so as to face the cam portion C located at the nearest position (see FIG. 14).

When the main body 31 of the cooling device 12 is lowered and the main pipe 34 and the branch pipe 35 reach predetermined positions, air is supplied from an air supply source (not shown) through the air pipe 33, and the air ejection holes 36a of the branch pipe 35 are provided. , 36b is blown toward the respective cam portions C of the respective camshafts W (see FIGS. 14 and 16). The heat treatment furnace 10
As shown in the figure, the time required from the end of the holding to the ejection of the air is about 1 minute, and the temperature drop of the camshaft W during this period remains at about 80 ° C.

The air is ejected by the cooling device 12 at a discharge pressure of, for example, 0.6 MPa for about 3 minutes. As shown in FIG. From (36b), air is sprayed almost uniformly over the entire circumference. Thereby, the cam portion C
Is rapidly cooled to about 500 ° C. as shown by TC in FIG. 17, and its composition becomes pearlite-rich. On the other hand, the journal J at the end, which is isolated by the mounting plates 23a and 23b and does not blow air, is naturally cooled (TN) as shown by the broken line in FIG. 17 and its structure becomes ferrite rich. On the other hand, the center journal J and the shaft axis A are not isolated by the mounting plates 23a and 23b, but show no similar temperature drop TN as the journal J because the air is not directly sprayed. Becomes ferrite rich. This is because the range of air that can be cooled is narrower than that of the cooling water, and only the portion where the air is directly sprayed at a certain flow rate or more is rapidly cooled.

When the air blowing is completed, the main body of the cooling device 12 is raised to the upper position, and the stopper is released, so that the heat treatment pallet 13 is conveyed by the second roller conveyor 11b, and the next process, for example, the precision It is sent to the cutting process for taking out. Thereafter, each time the heat treatment pallet 13 on which the unheated camshaft W is mounted is carried, the above heat treatment is repeated, and a large number of camshafts W are continuously fed.
Of the cam portion C and tempering of the journal portion J and the like are performed.

The cooling device 12 can blow air from the air blow holes 36a and 36b to one cam portion C with substantially the same blow amount regardless of the position of the branch pipe 35. Therefore, air is almost uniformly blown over the entire circumference of the cam portion C, and the cam portion C is evenly chilled. This also has the effect that the cam portion C can be surely chilled regardless of the phase in the rotation direction with respect to the longitudinal direction of the cam shaft W when mounted on the heat treatment pallet 13 (the position of the cam top). Further, such a cooling device 12 includes a main pipe 34, a branch pipe 35, and the air ejection holes 3.
By optimizing the arrangement interval of 6a and 36b, the cam portion C
And the like can be rapidly cooled selectively. This is effective when there is a portion that needs to be cut later, such as the journal J, or a portion that needs to maintain high toughness, such as the shaft A. Furthermore, since the heat treatment apparatus 2 having such a cooling device 12 can perform the casting and chilling processes independently, the casting cycle time can be shortened, and the manufacturing process of the camshaft W can be streamlined. In particular, since the heat treatment simultaneously processes a large number of camshafts W, the processing time per camshaft W can also be reduced.

The present invention is not limited to the above embodiment, but can be widely applied. For example, the number and arrangement of the main pipes 34 and the branch pipes 35 of the cooling device 12 are not limited to the embodiments, and may be any number and arrangement according to the number and arrangement of the camshafts W. In addition, the shape of the notch 27 of the mounting plates 23a and 23b can be an arbitrary shape such as a semicircle or a square. Further, the work to be subjected to such a heat treatment is not limited to the camshaft W, but a part of the crankshaft, an agricultural machine tool, a tool, a liner, etc. is chilled to increase wear resistance, and the other part maintains toughness. Applicable to those who do. Specifically, in the case of a crankshaft, a portion where the upper portion is chilled from the oil ring groove, which is the lowest ring groove at the top dead center of the piston, where the pin portion, the journal portion, and the cylinder liner are easily worn. It is. The liner is a hollow cylindrical member that forms a chill layer with a predetermined thickness on the inner surface and / or outer surface thereof to improve wear resistance. In these cases, the cooling device 12 is provided with air ejection means having a shape and an arrangement according to the shape of the work.

Further, the air supply means 32 may be configured to have only the main pipe 34 without the branch pipe 35. In this case, an opening is provided on the side surface 34a of the main pipe 34, and this opening is arranged so that the opening area is reduced from the opening end 52, which is one end on the air supply source side, to the other end. Make the amount of air blown from the air almost constant. The main pipe 34 is desirably arranged so that the air jetted from the openings of the plurality of main pipes 34 is almost uniformly jetted to a predetermined portion of the work. The direction of the opening may be perpendicular to the axis of the main pipe 34, or may be such that the air is ejected at an angle similar to the elevation and depression angles of the air ejection holes 36a and 36b of the embodiment. Can also.

Further, instead of arranging the main pipes 34 of the cooling device 12 vertically downward, the main pipes 34 are arranged horizontally and in the heat treatment furnace 1.
It may be extended toward zero. That is, the cooling device 12 is provided so as to be able to move backward at the exit of the heat treatment furnace 10,
The two main pipes 34 are arranged so as to extend horizontally. The heat treatment pallet 13 in this case adopts a configuration in which the longitudinal direction of the camshaft W is placed in a direction orthogonal to the main pipe 34. The heat treatment pallet 13 on which the camshaft W is placed is used as the heat treatment furnace 1
Since it is extruded from 0 toward the waiting cooling device 12, the air can be sprayed quickly, and the time until the start of rapid cooling can be shortened. After cooling, the cooling device 1
2 retreats, and the heat treatment pallet 13 is transported to the next step by the second roller conveyor 11b laid perpendicular to the longitudinal direction of the heat treatment furnace 10. And the main pipe 34
Can be extended in parallel with the shaft axis A of the camshaft W, and the branch pipes 35 can be arranged perpendicular to the shaft axis A.

[0042]

According to the present invention, from one end to the other end,
A cooling device that has an air supply hole with an array with a reduced opening area and makes the outflow of air from each air supply hole almost constant, so that the work is cooled uniformly regardless of the position of the air supply hole be able to. A branch pipe is connected to the air supply hole of the cooling device, and the branch pipe blows one of the predetermined portions of the work from a different angle to the center position of the predetermined portion with a hole diameter corresponding to the area of the predetermined portion. When attached, the work can be further cooled uniformly. And if it is a heat treatment apparatus equipped with these cooling devices,
Only a predetermined portion of the work heated in the heat treatment furnace can be rapidly and surely cooled.

[Brief description of the drawings]

FIG. 1 is a view showing a mold for casting a camshaft according to an embodiment.

FIG. 2 is a partially cutaway plan view of the heat treatment apparatus of the present embodiment.

FIG. 3 is a plan view of the heat treatment pallet of the present embodiment.

FIG. 4 is a front view of a heat treatment pallet.

FIG. 5 is a sectional view taken along line YY of FIG. 3;

6A is a front view of the mounting plate, and FIG. 6B is a plan view thereof.

FIG. 7A is a front view of the mounting plate, and FIG.

FIG. 8 is an explanatory diagram illustrating a procedure for mounting a camshaft on a heat treatment plate.

FIG. 9 is a front view of the cooling device.

FIG. 10 is a side view of the cooling device.

FIG. 11: (a) When the cooling device is in the upper position,
(B) It is a side view each showing the case where it is in a lower position.

FIG. 12 is a plan view of (a) a main pipe of an air supply unit;
(B) It is a side sectional view.

FIG. 13 is a front view showing a case where the cooling device is at a lower position.

FIG. 14 is an explanatory diagram illustrating a state in which air is blown from an air blowout hole to a cam portion.

15A is a front sectional view of a branch pipe, and FIG. 15B is a side sectional view of a branch pipe.

FIG. 16 is an explanatory diagram showing the flow of air in the main pipe and the branch pipe.

FIG. 17 is a time chart in a heat treatment.

[Explanation of symbols]

 Reference Signs List 2 heat treatment apparatus 10 heat treatment furnace 11 roller conveyor (conveying means) 12 cooling apparatus 13 heat treatment pallet (pallet) 22 support 23a, 23b mounting plate 24, 25, 28, 29 cylinder 27 cutout 31 main body 32 air blowing means 34 Main pipe 35 Branch pipe 36a, 36b Air ejection hole 60a-60h Air supply hole W Camshaft (work) C Cam part (predetermined part) J Journal part A Shaft shaft

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Watanabe 1-10-1 Shin-Sayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (72) Inventor Takeshi Sasaki 1-1-10-1, Shin-Sayama, Sayama City, Saitama Prefecture DA Engineering Co., Ltd. F term (reference) 4K034 AA04 BA02 BA10 DB03 FA01 FB03 FB07 FB09 GA08 4K042 AA17 BA03 BA13 DA06 DB07 DD05 DE02 DF01 EA01

Claims (4)

[Claims] 1. A cooling device having an air ejection means for spraying air onto a high-temperature work to cool it, said air ejection means having a main pipe through which air flows,
In the main pipe, along the longitudinal direction, air supply holes through which air flows out are provided at equal intervals, and the air supply holes extend from one end side, which is the air supply source side, to the other end side.
A cooling device used for heat treatment, wherein the cooling device has an arrangement in which the opening area is reduced. 2. The air jetting means includes a branch pipe communicating with the air supply hole, and the branch pipe includes an air jet hole for jetting air from a different angle to a predetermined portion of the work. The cooling device used for the heat treatment according to claim 1, characterized in that: 3. The air ejection hole, wherein air is ejected from a different angle to a center position of a predetermined portion of the work, and the air ejection hole has a hole diameter corresponding to an area of the predetermined portion. A cooling device used for the heat treatment according to claim 1 or 2. 4. A heat treatment furnace for heating the work, a conveying means for carrying the work into and out of the heat treatment furnace, and a structure capable of moving back and forth with respect to the heated work. And a cooling device used for the heat treatment according to any one of the above.