JP5511240B2 - Gas cooling device for work and gas cooling method - Google Patents

Description

  The present invention relates to a work gas cooling apparatus and a gas cooling method.

  In the manufacturing process of gears and other workpieces (steel parts) used for automobile internal parts (for example, transmission parts, etc.), in order to perform quenching processing, after the heat treatment is performed in the previous step, the cooling device Cooling takes place. Therefore, Patent Document 1 discloses a gas cooling method and gas in which a cooling gas is enclosed in a vacuum sealed container containing a workpiece (steel part), and the cooling gas is circulated by a fan in the vacuum sealed container to forcibly cool the workpiece. A cooling device is disclosed.

  In FIG. 1, the longitudinal cross-sectional view of the container 100 which is the pressure reduction sealed state in the conventional gas cooling device currently disclosed by patent document 1 is shown. The container 100 has a double structure including an outer cylinder 108 and an inner cylinder 109, and a cooling water passage 110 through which cooling water passes is formed between the double cylinders. A support base 112 is provided at the center 111 of the inner cylinder 109, and the work 120 to be cooled is held on the support base 112. Further, an intermediate cylinder 114 is disposed between the inner cylinder 109 and the support base 112. Between the intermediate cylinder 114 and the inner cylinder 109, between the intermediate cylinder 114 and the upper lid 101 of the container 100, and between the intermediate cylinder 114 and the container 100. Fluid flow paths 122 to 124 are formed between the bottom plate 102 and the bottom plate 102. Spaces 126 and 127 having an inverted truncated cone shape and a truncated cone shaped cross section are formed on the inner peripheral surface of the intermediate cylinder 114 that are narrowest at the central portion 111 and gradually expand in the vertical direction. An annular wall 129 is provided.

  In addition, a circulation fan 130 supported by the rotation shaft 131 is installed in the upper center of the intermediate cylinder 114, and the circulation fan 130 is operated (rotated) by the power of the motor 133 mounted on the upper portion of the upper lid 101. An internal duct 135 for rectifying the fluid flowing in the space 126 is disposed in the space 126 between the lower surface of the circulation fan 130 and the support base 112.

FIG. 2A shows a plan view of the internal duct 135 and FIG. 2B shows a front view of the internal duct 135. As shown in FIG. 2, the internal duct 135 includes an inverted frustoconical core portion 136 extending from the upper portion of the space 126 toward the center portion 111, and an outer circumferential surface of the core portion 136 that is spaced apart from each other in the circumferential direction. And a plurality of guide pieces 137 that extend outward in the radial direction and whose upper ends are curved in an arc in the same circumferential direction. An arbitrary one of the guide pieces 137 is fixed to the annular wall 129 of the intermediate cylinder 114, whereby the internal duct 135 is fixed.

A heat transfer fin 140 is provided on the inner peripheral surface of the inner cylinder 109. On the other hand, on the bottom plate 102 below the container 1, a lower rectifying plate 145 whose central portion swells upward in the shape of a truncated cone and whose peripheral portion curves upward in an arc shape is installed. The upper rectifying plate 146 whose central portion protrudes downward in the shape of an inverted truncated cone is installed. The rotating shaft 148 of the motor 133 is configured to pass through the central portion of the upper rectifying plate 146 and communicate with the circulation fan 130.

In the conventional gas cooling apparatus configured as described above, after the workpiece 120 is held on the support base 112, the cooling gas is introduced into the container 100 and the cooling gas is sealed in the container 100. Then, the circulation fan 130 is rotated by the operation of the motor 133, and the cooling gas is circulated in the fluid flow paths 122 to 124 as shown by arrows in FIG. The workpiece 120 is cooled for a predetermined time by the cooling gas circulating in the container 100. Here, the cooling gas in the container 100 is cooled at any time by contacting the heat transfer fins 140 that are water-cooled by the cooling water passing through the cooling water passage 110, and the cooling performance is always secured.

As the cooling gas, for example, one kind of inert gas, one kind or two or more kinds of mixed inert gas, hydrogen gas alone, or a mixed gas of hydrogen gas and inert gas is used.

JP 2000-87136 A

  However, when the workpiece is cooled using the gas cooling device described in Patent Document 1, the cooling gas contacts the upper surface of the workpiece from above, and then the cooling gas contacts the side and lower surfaces of the workpiece. The cooling in a state where the cooling gas was always in contact with the work could not be performed. As the workpiece, for example, a gear is exemplified, but since the tooth portion of the gear is provided on the side surface, when the workpiece is a gear, the tooth portion may not be uniformly cooled. Since the gear teeth are required to be hardened with extremely high precision due to their properties, it is necessary to perform uniform hardening (cooling) on the upper surface, side surface, and lower surface with high accuracy. That is, when extremely high accuracy uniformity is required for the work hardening process, the gas cooling device described in Patent Document 1 has a problem that sufficient accuracy cannot be ensured in the cooling.

In addition, since the upper surface and the lower surface of the workpiece are not uniformly cooled, there is a possibility that the shape of the entire workpiece is deformed, not limited to the gear teeth. This is because the speed of the cooling gas that contacts the upper surface of the workpiece is different from the speed of the cooling gas that contacts the lower surface of the workpiece, which causes a difference in the cooling rate between the upper surface and the lower surface.

  Accordingly, in view of the above problems, the object of the present invention is to make the work quenching process (cooling) extremely high by bringing a uniform cooling gas into contact with the upper surface, side surface and lower surface of the work when performing the work hardening process. An object of the present invention is to provide a gas cooling apparatus and a gas cooling method for a workpiece which are uniformly performed with high accuracy.

  According to the present invention, there is provided a gas cooling device that cools a workpiece by bringing a cooling gas into contact with the workpiece, the vacuum sealed container for storing the workpiece, a vacuum pump for evacuating the vacuum sealed container, and the vacuum sealed container A cooling gas supply source for supplying a cooling gas, wherein the decompression sealed container includes an upper lid, a bottom plate, an outer cylinder, and an inner cylinder, and a cooling fluid flow through which a cooling medium provided between the outer cylinder and the inner cylinder flows. A path, a support base for holding the workpiece provided at the center of the inner cylinder, an intermediate cylinder disposed between the inner cylinder and the support base, the intermediate cylinder, the inner cylinder, the upper lid, and the A cooling gas flow path formed between the bottom plate, a rectifying mechanism provided between the intermediate cylinder and the support, for rectifying the cooling gas toward the side surface of the workpiece, and an upper center of the intermediate cylinder A circulation fan arranged on the circulation circuit, and the circulation fan Gas cooling apparatus is provided comprising, a motor for driving the fan.

  Further, cooling fins may be formed on the inner peripheral surface of the inner cylinder, and the rotational speed of the circulation fan may be variable. An internal duct for rectifying the cooling gas flowing in the intermediate cylinder may be provided between the lower surface of the circulation fan and the support base. The internal duct includes a truncated cone-shaped core portion and a plurality of guides extending in an up-down direction and a radial direction spaced apart from each other on an outer peripheral surface of the core portion, the upper ends of which are curved in an arc shape in the same circumferential direction. It may consist of pieces.

  On the upper surface of the bottom plate, there may be a lower rectifying plate whose central portion swells upward in a truncated cone shape and whose peripheral portion is curved upward in an arc shape, and whose central portion is an inverted cone on the lower surface of the upper lid. You may have the upper baffle which protrudes below in trapezoid shape.

On the other hand, according to another aspect of the present invention, there is provided a gas cooling method for cooling a workpiece using the gas cooling apparatus , wherein a cooling gas is enclosed in a vacuum sealed container containing the workpiece, and the vacuum sealed container There is provided a gas cooling method in which a cooling gas is circulated in the reduced-pressure sealed container by a circulation fan provided in the upper center of the container, and the workpiece is cooled by bringing the cooling gas into uniform contact with the side surface of the workpiece.

  The number of rotations of the circulation fan may be freely changed, and the cooling gas may be an inert gas having a pressure of 1 MPa or less, hydrogen gas, or a mixed gas of these two kinds.

  According to the present invention, when quenching a workpiece, uniform cooling gas is brought into contact with the upper surface, side surface and lower surface of the workpiece, and the workpiece is quenched and cooled uniformly with extremely high accuracy. Deformation can be prevented. Moreover, since the working pressure is low, a complicated heat exchanger is not required, and a general-purpose motor having a low output can be used, the equipment can be simplified and the equipment cost can be reduced.

It is a longitudinal cross-sectional view of the container 100 which is the pressure reduction sealed state in the conventional gas cooling device. (A) It is a top view of the internal duct 135 in the conventional gas cooling device. (B) It is a front view of the internal duct 135 in the conventional gas cooling device. It is a schematic explanatory drawing of the gas cooling device 1 whole. 3 is an explanatory diagram showing a configuration of a container 10. FIG. (A) It is a top view of the internal duct 40 in the gas cooling device 1. FIG. (B) It is a front view of the internal duct 40 in the gas cooling device 1. FIG. It is explanatory drawing which shows the flow of the cooling gas of the workpiece | work 5 vicinity.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 3 is a schematic explanatory diagram of the entire gas cooling apparatus 1 according to the present embodiment. The container 10 into which the work 5 is charged and which can be depressurized and sealed is in communication with a vacuum pump 14 via an exhaust path 12 including an exhaust valve 11. In addition, the container 10 communicates with a storage unit 20 that stores cooling gas via an introduction path 17 including an introduction valve 16.

  FIG. 4 is an explanatory view showing the configuration of the container 10. The container 10 has a double cylinder structure including an outer cylinder 24 and an inner cylinder 25, and a cooling water passage 28 through which cooling water passes is formed between the outer cylinder 24 and the inner cylinder 25. An entrance / exit 27 for carrying in / out the workpiece 5 is provided on a side surface of the container 10. A support base 30 that holds the work 5 is installed at the center of the inner cylinder 25. For example, when the work 5 that is a ring-shaped steel part such as a gear is cooled, the support base 30 is held by the support base 30. An intermediate cylinder 32 is disposed between the inner cylinder 25 and the support base 30. Fluid passages 37 to 39 are formed between the intermediate cylinder 32 and the upper lid 34 of the container 10, between the intermediate cylinder 32 and the inner cylinder 25, and between the intermediate cylinder 32 and the bottom plate 35 of the container 10. The upper cover 34 is provided with the introduction passage 17 shown in FIG. 3, and the bottom plate 35 is provided with the exhaust passage 12 shown in FIG. 3. Although not shown in FIG. It communicates with the pump 14.

  A frustoconical (upwardly convex) internal duct 40 is disposed on the upper portion of the support 30 at the center of the intermediate cylinder 32. The internal duct 40 is located on the side of the internal duct 40, that is, between the intermediate cylinder 32 and the internal duct 40. A space 42 that narrows downward is formed. FIG. 5 shows a plan view (FIG. 5 a) and a front view (FIG. 5 b) of the internal duct 40. Here, the inner duct 40 extends in the vertical direction and the radial direction away from each other on the outer peripheral surface of the truncated cone-shaped core part 40a and the core part 40a, and the upper ends of the inner duct 40 are curved in an arc shape on the same circumference. It consists of a guide piece 40b. The cooling gas flows along the guide piece 40b.

In addition, a rectifying mechanism 45 that rectifies the fluid flowing in the space 42 in the direction of the support base 30 (the direction of the workpiece 5) is installed in the lower portion of the space 42. The rectifying mechanism 45 has a donut shape surrounding the support base 30 and the workpiece 5, and includes a plurality of curved rectifying channels 45a and a discharge portion 45b for discharging the cooled gas. As shown in FIG. 4, one end portion of the rectifying channel 45 a faces the space 42 and opens upward, and the other end portion faces the side surface of the work 5 held by the support base 30. So that it is open. In addition, a truncated cone-shaped discharge portion 45b that extends downward from the container 10 is disposed below the rectifying channel 45a.

  A circulation fan 50 supported by a rotation shaft 49 is installed at the upper center in the intermediate cylinder 32, and the circulation fan 50 is rotated by driving a motor 51 placed on the upper lid 34 connected to the rotation shaft 49. .

  As shown in FIG. 4, a plurality of steel heat transfer fins 53 are attached to the inner peripheral surface of the inner cylinder 25, and the cooling capacity of the cooling water passage 28 is transmitted to the heat transfer fins 53. Yes. On the other hand, on the lower surface of the upper lid 34, an upper rectifying plate 60 whose central portion 60a protrudes downward in the shape of an inverted truncated cone is disposed, and on the upper surface of the bottom plate 35, the central portion 61a swells in a truncated cone shape. A lower rectifying plate 61 in which 61b curves upward in an arc is arranged.

  In the gas cooling apparatus 1 configured as described above with reference to FIGS. 3 and 4, for example, gas cooling of the workpiece 5 typified by a quenching process of steel parts is performed. The gas cooling will be described below.

  First, for example, an inert gas such as nitrogen or helium, hydrogen gas, or a cooling gas that is a mixture of two or three of these gases is introduced from the reservoir 20 into the container 10 through the introduction path 17. When the cooling gas is introduced, the inside of the container 10 is depressurized by the operation of the vacuum pump 14. The internal pressure in the container 10 after the introduction of the cooling gas is preferably 1 MPa or less. The pressure has sufficient cooling capacity, and uniform cooling is possible. Then, the high-temperature work 5 that has been subjected to the heat treatment in the preceding step is carried into the container 10 from the entrance 27. The loaded work 5 is held on the support 30.

  Subsequently, the circulation fan 50 is rotated by the operation of the motor 51, and the cooling gas introduced into the container 10 is circulated. Here, the circulation path of the cooling gas inside the container 10 is in accordance with the rectification of the cooling gas by the upper rectifying plate 60, the lower rectifying plate 61 and the rectifying mechanism 45. This is a route passing through (route as shown by an arrow in FIG. 4). The work 5 is cooled by rotating the circulation fan 50 for a predetermined time to circulate the cooling gas into the container 10. Here, the cooling gas passing through the fluid passage 38 comes into contact with the heat transfer fins 53 attached to the inner peripheral surface of the inner cylinder 25. Since the heat transfer fins 53 are water-cooled by the cooling ability of the cooling water passages 28, the cooling gas in contact with the heat transfer fins 53 is also cooled. That is, the cooling gas circulating in the container 10 cools the work 5 by heat exchange with the hot work 5 and is cooled by the contact with the heat transfer fins 53, so that the cooling ability of the cooling gas is ensured, The workpiece 5 is efficiently cooled.

  FIG. 6 is an explanatory diagram showing the flow of the cooling gas in the vicinity of the workpiece 5 in the gas cooling apparatus 1 according to the present embodiment. In addition, the arrow in FIG. 6 shows the flow of the cooling gas. As shown in FIG. 6, the opening of the rectifying channel 45 a is opened so that the cooling gas is injected perpendicularly to the side surface of the workpiece 5. Therefore, the cooling gas is uniformly sprayed on the side surface of the work 5, and cooling is performed uniformly. Further, by appropriately changing the positional relationship between the rectifying mechanism 45 (rectifying flow path 45a) and the work 5, the cooling gas can be uniformly flowed and brought into contact with the upper and lower surfaces of the work 5 as indicated by arrows in FIG. Since it is possible to adopt such a device configuration, it is possible to make the cooling gas flow and contact uniformly on the upper surface and the lower surface of the work 5 by making the positional relationship between the rectifying mechanism 45 and the work 5 appropriate. It becomes. That is, by making the positional relationship between the rectifying mechanism 45 and the workpiece 5 suitable, the cooling gas can be uniformly brought into contact with the side surface, the upper surface, and the lower surface of the workpiece 5.

  Therefore, compared to the conventional method of flowing the cooling gas from the upper surface side of the workpiece, the amount of the cooling gas sprayed on the upper surface and the lower surface of the workpiece 5 and the flow velocity are uniform, and the upper surface and the lower surface of the workpiece 5 are uniformly cooled. Thus, deformation of the work 5 that occurs due to uneven cooling of the upper surface and the lower surface of the work 5 is prevented. Further, the tooth portion in the gear exemplified as the workpiece 5 is a side portion of the normal workpiece 5, and according to the gas cooling device 1 according to the present embodiment, the entire side portion is also cooled uniformly. The gas cooling device 1 according to the present embodiment is also useful for cooling (quenching) the gear teeth that require extremely fine uniformity.

  As mentioned above, although an example of embodiment of this invention was demonstrated, this invention is not limited to the form of illustration. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

  For example, in the above-described embodiment, the opening of the rectifying channel 45a is arranged so that the cooling gas is injected perpendicularly to the side surface of the work 5, but the present invention is not limited to this. It is desirable to adjust the angle of the opening and the position of the rectifying channel 45a so that the cooling gas uniformly contacts the side surface and the upper and lower surfaces. Further, the shape of the internal duct 40 is a truncated cone shape, the upper rectifying plate 60 has a central portion 60a protruding downward in an inverted truncated conical shape, and the lower rectifying plate 61 has a central portion 61a having a central portion 61a. Although the shape of the frustoconical shape is raised and the peripheral portion 61b is curved upward in an arc shape, the present invention is not limited to this, and a rectifying plate that efficiently circulates cooling gas in the container 10 It is desirable to appropriately determine the shape.

  Moreover, in the said embodiment, although the gear which is a steel component was illustrated and demonstrated as the workpiece | work 5, the application object of this invention is not restricted to this, High-temperature steel materials, components, etc. which were heat-processed etc. If so, uniform cooling can be easily performed using the present invention.

  The present invention is applicable to a work gas cooling apparatus and a gas cooling method.

DESCRIPTION OF SYMBOLS 1 ... Gas cooling device 5 ... Work 10 ... Container 11 ... Exhaust valve 12 ... Exhaust path 16 ... Introductory valve 17 ... Introductory path 20 ... Storage part 24 ... Outer cylinder 25 ... Inner cylinder 27 ... Outlet 28 ... Cooling water channel 30 ... Support stand 32 ... Intermediate cylinder 34 ... Upper lid 35 ... Bottom plate 37, 38, 39 ... Fluid passage 40 ... Internal duct 40a ... Core part 40b ... Guide piece 42 ... Space 45 ... Rectification mechanism 45a ... Rectification flow path 45b ... Discharge part 49 ... Rotating shaft 50 ... Circulating fan 53 ... Heat transfer fin 60 ... Upper current plate 61 ... Lower current plate

Claims (11)

A gas cooling device that cools a workpiece by bringing cooling gas into contact therewith,
A vacuum sealed container to put the work,
A vacuum pump for evacuating the vacuum sealed container;
A cooling gas supply source for supplying a cooling gas into the vacuum sealed container,
The vacuum sealed container is composed of an upper lid, a bottom plate, an outer cylinder and an inner cylinder,
A cooling fluid flow path through which a cooling medium provided between the outer cylinder and the inner cylinder flows;
A support base for holding the workpiece provided at the center of the inner cylinder;
An intermediate cylinder disposed between the inner cylinder and the support;
A cooling gas flow path formed between the intermediate cylinder and the inner cylinder, the upper lid and the bottom plate,
A rectifying mechanism that is provided between the intermediate cylinder and the support and rectifies the cooling gas toward the side surface of the workpiece;
A circulation fan disposed in the upper center of the intermediate cylinder;
A gas cooling device comprising: a motor for driving the circulation fan. The gas cooling device according to claim 1, wherein cooling fins are formed on an inner peripheral surface of the inner cylinder. The gas cooling device according to claim 1 or 2, wherein the number of rotations of the circulation fan is variable. The gas cooling device according to any one of claims 1 to 3, further comprising an internal duct for rectifying the cooling gas flowing in the intermediate cylinder between the lower surface of the circulation fan and the support base. The internal duct includes a truncated cone-shaped core portion, a plurality of guide pieces that extend in the vertical and radial directions away from each other on the outer peripheral surface of the core portion, and whose upper ends are curved in an arc shape in the same circumferential direction. The gas cooling device according to claim 4, comprising: The gas cooling device according to any one of claims 1 to 5, further comprising a lower rectifying plate having a central portion that rises upward in a truncated cone shape and a peripheral portion that curves upward in an arc shape on an upper surface of the bottom plate. The gas cooling device according to any one of claims 1 to 6, further comprising an upper baffle plate whose central portion protrudes downward in an inverted truncated cone shape on a lower surface of the upper lid. The gas cooling device according to any one of claims 1 to 7, wherein the cooling gas is an inert gas having a pressure of 1 MPa or less, hydrogen gas, or a mixed gas of these two kinds. A gas cooling method for cooling a workpiece using the gas cooling device according to claim 1 ,
Cooling gas is sealed in a vacuum sealed container containing the workpiece, and the cooling gas is circulated in the vacuum sealed container by a circulation fan provided in the upper center of the vacuum sealed container.
A gas cooling method in which a cooling gas is uniformly brought into contact with a side surface portion of the workpiece to cool the workpiece. The gas cooling method according to claim 9 , wherein the number of rotations of the circulation fan can be freely changed. The gas cooling method according to claim 9 or 10, wherein the cooling gas is an inert gas, a hydrogen gas, or a mixed gas of these two at a pressure of 1 MPa or less.

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