JP5613449B2 - Cooling apparatus and cooling method for drawing mold - Google Patents

Description

  The present invention, for example, after blanking a steel sheet in a press factory or the like, suppresses the processing heat during press forming in which drawing is performed with a draw mold, and the upper die is baked due to thermal expansion and the cracks and galling of the steel sheet associated therewith. It relates to technology to prevent.

Conventionally, for example, when drawing a steel plate such as a high-tensile steel plate used in an automobile, the steel plate is sandwiched between an upper die and a blank holder, and then processing such as deep drawing between the lower die is continuously performed. If this is done, the die-matching surface on the deep drawing side of the upper die may be seized due to processing heat. For this reason, the equipment is stopped and repair work is performed at that time.
This is because, on the die-matching surface on the deep drawing side, the steel sheet stretched when the steel plate is formed flows while sliding along the die-matching surface, so frictional heat concentrates on the same part, and the die-matching surface As a result of the expansion of the side surface, it becomes impossible to secure a certain clearance with the steel sheet, the steel sheet will suffer from molding quality defects such as cracks and galling, and the upper mold matching surface will also seize and repair work is required. is there.

  Therefore, as a countermeasure against the processing heat generated from the draw mold in deep drawing, a water cooling system that cools the draw mold by jetting a cooling liquid and an air cooling system that cools by blowing air or the like are known. In the case of this water cooling method, cracks and the like are likely to be generated in the cooling portion due to repeated rapid temperature changes, and wiping work is required in a subsequent process, which leads to a decrease in workability. In addition, as the latter air cooling method, air vent holes are provided in the upper and lower mold surfaces, and a compressed air source is connected to a specific location of the air vent hole via a solenoid valve, and the bottom dead center of the press When the signal is received, a technique (for example, refer to Patent Document 1) is known in which a solenoid valve is operated to send compressed air to a specific portion of an air vent hole.

No. 4-9056

  However, in the case of the technique disclosed in Patent Document 1, it is necessary not only to provide a dedicated passage such as an air vent hole in the mold, but also to supply air, the sensor detects that the upper mold has reached the bottom dead center. Therefore, when the draw mold is cooled, it is possible to cool the mold surface by simply blowing cold air for a short time. There is a problem that it is difficult to prevent.

  Accordingly, the present invention is to more effectively cool the molding part of the drawing mold so that the expansion of the mold itself can be suppressed even in the case of continuous molding, and the cooling structure can be simplified and configured easily. With the goal.

  In order to achieve the above object, the present invention provides a cooling device for cooling a forming part of a drawing mold in which a casting hole is formed at a predetermined position of the upper mold, and on the back side of a bead part on at least one side of the upper mold. Of the periphery of the inner wall of the cast hole that is positioned, at least the adjacent cast hole or the communicating hole part that communicates with the outside air is covered with a heat shielding plate, and a part of the inner space is placed in the cast hole located on the back side of the bead part. An enclosure member that can locally enclose the portion is provided, and a cooling device main body is disposed in a cast hole located on the back side of the bead portion, and an enclosure space surrounded by the surrounding member from the cooling device main body Cold air was supplied inside.

Such an upper die-cut hole is formed from the viewpoint of, for example, reducing the weight of the mold, but the temperature of the mold is reduced by the processing heat when the molded part of such a drawing mold is cooled. Cooling is performed by using an upper die-casting hole located on the back side of the deep drawing bead portion that is likely to rise. For this reason, for example, in the cast hole located on the back side of the bead part, the part closest to the forming part is narrowly surrounded by the surrounding member, and the processing heat generated at the time of forming is sent by sending cold air into the surrounding space. To effectively cool. In addition, by arranging a heat shielding plate at a predetermined location around the inner wall in the cast hole, the cast hole can be put in a semi-sealed state, for example, using cold air that has escaped from the surrounding space. The entire mold can be cooled, and the mold itself can be prevented from expanding.

In the present invention, the surrounding member has an L-shaped cross section that can cover the upper surface of the surrounding space and one side surface in the width direction, and at least one of both side surfaces in the longitudinal direction is open, or The box shape is such that the upper and side surfaces of the space can be covered and a hole is formed on either the upper surface or the side surface.
In this way, by providing a hole and an opening in the surrounding space surrounded by the surrounding member and not completely sealing, dew condensation can be prevented and cold air discharged from the hole and the opening can prevent The inside is cooled, and the effect of cooling the entire mold is enhanced.

In the present invention, a low-temperature air generator capable of generating cold air by receiving supply of factory air is used as the cooling device body.
As such a low-temperature air generator, for example, an apparatus that uses a so-called vortex effect and can generate cold air when supplied with compressed air can be applied.

By enclosing a part of the inner space of the casting hole located on the back side of the bead portion of the upper mold narrowly by the surrounding member and supplying cold air sent from the cooling device main body arranged in the casting hole into the surrounding space, The processing heat generated in the molding part near the bead part can be effectively cooled, and by providing a heat shielding plate at a predetermined location on the inner wall of the punched hole, expansion of the mold itself can be suppressed and molding quality can be suppressed. And drawing work can be performed efficiently.
At this time, as the surrounding member, if at least one of both side surfaces in the longitudinal direction is an L-shaped cross section that is open, or a box shape in which a hole is formed on either the upper surface or the side surface, Condensation can be prevented, and the inside of the cast hole is cooled, thereby increasing the effect of cooling the entire mold.
Further, if a low temperature air generator capable of generating cold air by receiving supply of factory air is used as the cooling device main body, it can be simply configured.

It is a front view which shows an example of the punching hole of the upper die of a deep drawing metal mold | die. It is a top view of an upper model. It is the sectional view on the AA line of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. It is a principal part enlarged view of FIG. It is the BB sectional view taken on the line of FIG. It is explanatory drawing explaining the action | operation of a deep drawing metal mold | die.

Embodiments of the present invention will be described with reference to the accompanying drawings.
The drawing mold cooling apparatus according to the present invention can effectively suppress the expansion of the mold itself even in the case of continuous molding by cooling the molding part more effectively, and the cooling structure can be simplified and configured easily. It is characterized by cooling using the cast hole formed in the upper mold | type.

Therefore, before describing the cooling apparatus of the present invention, the operation of the drawing mold to which the present cooling apparatus is applied will be described with reference to FIG.
The drawing mold 1 includes a lower mold 3 placed on a press bolster 2, an upper mold 5 that can be moved up and down by a press ram 4, and a blank holder 7 supported by cushion pins 6. FIG. When the work W such as a steel plate is placed on the blank holder 7 with the upper mold 5 raised as shown in a), the upper mold 5 is lowered as shown in FIG. 7B. The workpiece W is sandwiched between the blank holder 7 and the upper die 5, and as shown in FIG. 7C, the upper die 5 and the blank holder 7 are lowered so that the workpiece W is molded into the lower die 3 and the upper die 5. Drawing is performed by 5a.

  At this time, a bead portion b is provided on the die-matching surface of the upper die 5 in the vicinity of the molding portion 5a, and the workpiece W is sandwiched between the bead portion b and the blank holder 7; When the deformation amount of the workpiece is large as in the case of drawing, the bead portion b acts as a so-called sink bead, and a part of the workpiece W flows into the molding portion 5a side through the bead portion b. For this reason, in the vicinity of the bead portion b, particularly around the side surface in the vicinity of the molding portion 5a, the temperature of the upper die 5 expands at the same time due to frictional heat, and the deep drawing is continuously repeated. The upper die 5 is burned out, and the workpiece W has problems such as cracks and galling.

  Therefore, the present invention has been made to prevent problems caused by processing heat in such a drawing mold 1.

  For the purpose of reducing the weight, the upper die 5 is formed with a hole 8 as shown in FIGS. 1 and 2, each hole 8, and a communication hole 9 for communicating with the outside air. Has been. Further, the shape of the molded part 5a is the deep drawing side on the right side of the figure compared to the left side, and when the upper part 5 is molded, the bead part b on the right side of the figure is on the left side. The material flows more than the bead portion b, the processing heat due to friction increases, and problems such as seizure tend to occur. Therefore, in the case of the present invention, the case where the periphery of the deep drawing side 5a on the right side of FIGS. Further, at this time, since two casting holes 8 are formed on the back side of the right bead portion b, the first casting hole 8a and the second casting hole are used as the casting holes 8 for convenience. This is referred to as 8b.

  First, as shown in FIGS. 2 and 3, an air hose 11 is arranged using each of the cast holes 8 and the communication holes 9 in one row, and the upstream end is connected to the factory air source via the air coupler 12. 13 and the downstream end is connected to the cooling device main body 14 disposed in the first cast hole 8a.

This cooling device main body 14 uses a so-called vortex tube that generates a low temperature by a vortex effect when compressed air is sent, and has a performance capable of cooling from the outside air temperature to a maximum of about 30 ° C. Is sent to the cooling hose 11k, and the warm exhaust gas from which the cool air has been removed is sent to the hot air hose 11h so that it can be exhausted. And the front-end | tip part of the cooling hose 11k has faced the surrounding space 17 formed in the 1st, 2nd casting hole 8a, 8b mentioned later, and the front-end | tip part of the warm air hose 11h is the upper mold | type 5's. Facing outside space.

  As shown in FIG. 4, a heat shielding plate 15 for covering the opening of the communication hole 9 and shielding heat from escaping to the outside is provided on the inner peripheral walls of the first and second cast holes 8a and 8b. The first and second punching holes 8a and 8b are arranged in a semi-sealed state, and a L-shaped cross section that can narrowly surround a part of the internal space between the wall surface and the bottom surface near the molding portion 5a. A mold surrounding member 16 is provided, and an surrounding space 17 is defined by the surrounding member 16. Further, both side portions of the surrounding member 16 in the longitudinal direction are opened, and the cold air can be fed into the surrounding space 17 from the cold air hose 11k as described above.

  For this reason, as shown in FIGS. 5 and 6, the heat shielding plate 15 closer to the molding portion 5a of the first cast hole 8a is provided with an insertion hole 15a for allowing the air hose 11 to pass therethrough. The heat shielding plate 15 on the side opposite to the molding part 5a side of the cast hole 8a is provided with an insertion hole 15b through which the hot air hose 11h and the cooling device main body 14 are inserted.

In addition, in order to define the surrounding space 17, the surrounding member 16 has an L-shaped cross section in the present embodiment, and both side portions in the longitudinal direction are opened. However, both side portions are opened and completely sealed. The reason for not doing so is to prevent condensation. Also, instead of opening both sides, only one side is opened, a gap is provided in the ceiling surface portion of the surrounding member 16, or a gap is provided in the side surface portion in the width direction. Also good.
Further, the shape of the surrounding member 16 may be a box shape covering the upper surface and the side surface. In this case as well, a gap or the like is provided at an arbitrary location, and the cold air in the surrounding space 17 passes through the gaps and the punched holes 8a and 8b. It is preferable to escape inside.
Further, the material of the surrounding member 16 is suitably a steel material that is durable against processing heat, but is not limited thereto.

  The present cooling device is constituted by the air hose 11, the cooling device main body 14, the cooling hose 11 k, the hot air hose 11 h, the heat shielding plate 15, the surrounding member 16, and the like. The operation of the apparatus will be described.

  When performing the draw molding, the operator attaches the mold to a press machine (not shown), and connects the factory air source 13 near the press machine to the air coupler 12 at the tip of the air hose 11. Then, the compressed air sent from the factory air source 13 is supplied to the cooling device main body 14 through the air coupler 12, and the cold air cooled by the vortex effect in the device main body 14 is sent into the surrounding space 17 through the cold air hose 11k. Along with this, the hot air from which the cold air has been extracted is exhausted to the outside from the hot air hose 11h.

  At this time, the cooling time, cooling temperature, etc. can be set freely depending on the outside air temperature, factory environment, etc., but as a guideline for setting the cooling temperature, the time when room temperature is likely to rise such as in summer In order to approach the surface temperature close to winter, the surface temperature is set to be at least about 10 to 15 ° C.

  Then, the workpiece W is set on the blank holder 7, the workpiece W is sandwiched between the upper mold 5 and the blank holder 7, and the workpiece W is lowered to perform draw molding. The bead portion b on the deep drawing side on the middle right side is a so-called sink bead, and the amount of sliding of the material is increased and processing heat due to friction is generated, but since the cooled surrounding space 17 is disposed in the vicinity thereof, The heat generating part can be effectively cooled.

  Further, since the cool air discharged from the open portions on both sides of the surrounding member 16 cools the entire inside of the first and second cast holes 8a and 8b, expansion of the mold surface can be suppressed, and continuous draw molding is performed. Even if it repeats, it can work without the need for repair.

In addition, this invention is not limited to the above embodiments. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention.
For example, the cooling device main body 14 may be provided in a plurality of cast holes 8 immediately above or in the vicinity of the bead portion b, and there are two cast holes 8a and 8b immediately above or near the bead portion b on one side. It is not limited to individual.
Furthermore, as another low-temperature air generator using factory air, for example, a gas cooler, a refrigeration gas cooler, or the like may be used in addition to the one using the vortex effect as in the above embodiment.

  It can be expected to be used in a wide range in the future because it can prevent the heat of processing especially during deep drawing and deterioration of molding quality due to die expansion. .

DESCRIPTION OF SYMBOLS 1 ... Drawing mold, 5 ... Upper mold, 5a ... Molding part, 8 ... Cast hole, 8a ... First cast hole, 8b ... Second cast hole, 14 ... Cooling device main body, 15 ... Heat shielding plate , 16 ... Go member, 17 ... Go space, b ... Bead part.

Claims (4)

A cooling device for cooling a molding part of a drawing mold in which a casting hole is formed at a predetermined position of the upper mold, and around the inner wall of the casting hole located on the back side of the bead part on at least one side of the upper mold Among them, at least the adjacent core hole or the communication hole portion communicating with the outside air is covered with a heat shielding plate, and a part of the inner space is locally narrowly enclosed in the core hole located on the back side of the bead portion. provided with a enclosing member which can, by disposing the cooling device main body in the hole punching cast positioned on the back side of the bead portion, supplying cool air to the enclosed space surrounded by the surrounding member from the cooling unit main body, further The surrounding member has an L-shaped cross section that can cover the upper surface of the surrounding space surrounded by the surrounding member and one side surface in the width direction and at least one of both side surfaces in the longitudinal direction is open, or Go Sky The upper and side surfaces can be covered and an upper surface or diaphragm forming mold cooling device, characterized in that the hole is a formed box-shape on either side.   The drawing mold cooling device according to claim 1, wherein the cooling device main body uses a low-temperature air generator capable of generating cold air by receiving supply of factory air. A cooling method for cooling a forming part of a drawing mold in which a cast hole is formed at a predetermined position of an upper mold, which can cover the upper surface and one side surface in the width direction and at least either of both side surfaces in the longitudinal direction The upper die-cut hole is formed by an enclosure member having an L-shaped cross section that is open on one side or a box-shaped enclosure member that can cover the upper surface and the side surface and has a hole on either the upper surface or the side surface. A drawing mold cooling method characterized in that an enclosure space is formed at a predetermined position in the inside , and cooling air is supplied into the enclosure space , whereby the molding portion is cooled from the side of the upper mold hole. . The cooling of the drawing mold according to claim 3, wherein a cooling device main body capable of constantly generating cold air using factory air is used for supplying cold air into the core hole. Method.