JP4845813B2 - Press working equipment in die quench method - Google Patents

Description

  The present invention relates to a press working apparatus for press-molding and quenching a heated steel material with a pair of upper and lower molds in a die quench method (hot press method).

  Currently, in the field of automobile parts and the like, parts such as door beams and bumpers are produced by a die quench method (hot press method) in order to reduce the weight of the automobile parts and make the material suitable for use. At present, automotive parts are manufactured by punching and trimming steel materials before hot press forming, and then press forming. For this reason, the accuracy of the parts depends on the positioning accuracy of the steel material, and there is a problem that high-precision automobile parts cannot be obtained. Therefore, in order to adopt as a body part that requires high accuracy, post-processing is required after press molding, and accordingly, the number of processing steps increases, resulting in high cost of the part.

Therefore, conventionally, in die quench method, heated plate-shaped steel material is press-molded, and at the same time, excision processing such as drilling and trimming is performed, thereby preventing an increase in the number of processing steps and producing parts at low cost. A technique has been proposed (for example, Patent Document 1).
In such a die quench method, a steel material subjected to press forming is preheated to a quenching temperature of, for example, 750 to 1000 ° C., and the steel material is conveyed to a forming press machine so that the steel material is pressed at a relatively low temperature in a high temperature state. Installed in a mold, press-molded with the press mold, and at the same time, drilling and trimming, etc., and quenching and quenching the product to produce parts with excellent tensile strength etc. .

JP 2005-248253 A

By the way, in the conventional press die used for the die quench method mentioned above, temperature change arises in the said die by the influence of the steel materials heated to the quenching temperature at the time of press molding, and thermal expansion and contraction will occur in connection with it. Conventional press molds are also provided with cooling means and are always cooled by the cooling means. However, it is difficult to keep the molds at a constant temperature by instantaneously lowering the molds to room temperature.
For example, when the product 60 is continuously produced using the press mold 50 as shown in FIGS. 4 and 5, even if the mold 50 is cooled, the mold 50 is influenced by the heated steel material. Will rise to around 100 ° C. Although a method of cooling the mold 50 by dropping the production cycle is also conceivable, it is not practical, and the temperature of the mold 50 always rises when the press machine is operated in a high production cycle in consideration of mass production. become.

Further, such a press die 50 is composed of an upper die (upper blade) 51 and a lower die (lower blade) 52 which are a pair of upper and lower dies, and the lower die 52 has an integral structure. Normally, the clearance c between the upper mold 51 and the lower mold 52 when performing cutting such as trimming is about 10% of the plate thickness of the product 60.
If the thickness of the product 60 is 2 mm, the clearance c on one side is 0.2 mm. When the length of the product 60 is 1000 mm, the temperature change that is 0.2 mm in calculation is
Thermal expansion amount (X) = 1.2 × 10 ⁻⁵ × L × Δθ X = 0.4 (both sides converted to 0.2 mm on one side), L = 1000 to Δθ≈33 ° C., room temperature 20 ° C. When the mold temperature reaches 53 ° C., the upper mold 51 and the lower mold 52 interfere with each other, and a chipping of the blade occurs, making it difficult to perform trimming and other cutting operations simultaneously with press molding. It becomes.

  As a result, in the structure of the conventional press die, unless the thermal expansion and contraction is anticipated, the continuous production of the product 60 becomes impossible. The problem is that high quality products cannot be obtained. If excision processing such as drilling or trimming is performed after press molding, the die quench method is quenched by cooling with the mold 50 at the same time as press molding, so the hardness of the steel material is greatly improved and tools are used. When excavation such as drilling or trimming is performed, the tool is liable to be damaged and the tool life is very short.

  The present invention has been made in view of such a situation, and an object thereof is a relatively inexpensive structure, which suppresses thermal expansion and contraction of a mold when continuous production is performed, enables mass production of products, and presses. Pressing in the die quench method that allows cutting such as trimming at the same time as forming, can process steel without increasing the number of processes, produces high-quality products, and reduces production costs It is to provide a processing apparatus.

  In order to solve the above-described problems of the prior art, the present invention is a press working apparatus in a die quench method for press-molding and quenching a heated steel material with a pair of upper and lower molds, and installing the steel material The lower mold is divided into a plurality of block molds, and these block molds are mounted on the base with a gap provided between adjacent block molds.

In the press working apparatus of the present invention, the following configuration is particularly preferable.
(1) A plate-like heat insulating material is disposed between the block mold and the base.
(2) The base is provided with cooling means for cooling it.
(3) A plate-like heat insulating material is disposed between the block mold and the base, and cooling means for cooling the base is provided on the base.

[Action]
In the press working apparatus in the die quench method according to the present invention, the lower mold for installing the heated steel material is divided into a plurality of block molds, and these block molds are mounted on the base with gaps therebetween, so that the quenching temperature Steel material that has been heated up to a pair of upper and lower molds, and clamped between them to perform press forming and simultaneously perform excision processing such as drilling and trimming, and the steel material held between the upper and lower pair of molds Even when a series of production steps of quenching and quenching is continuously performed, the overall length of the block mold is shorter than the lower mold of the integral structure, and the amount of thermal expansion and contraction can be suppressed. Even if the block mold expands slightly due to heat from the steel material, the amount of elongation can be absorbed by the gaps between the block molds, and the clearance between the upper mold and the lower mold is secured. Then, the interference between the upper mold and the lower mold does not occur at the cut portion.

  Further, in the press working apparatus of the present invention, since a plate-shaped heat insulating material is disposed between the block mold and the base, heat from the steel material and the lower mold is blocked by the heat insulating material, and the heat insulating material It is possible to prevent or suppress the situation of being transmitted to the base located on the lower side.

  Furthermore, in the press working apparatus of the present invention, since the base is provided with a cooling means for cooling the base, the cooling means effectively cools the base even if heat from the steel material and the lower mold is transferred to the base. And even if it does not provide a heat insulating material, it becomes possible to suppress the thermal expansion of a base which affects the cutting part of an upper model and a lower model. Moreover, when a heat insulating material is provided, it becomes more reliable to suppress the thermal expansion of the base by a synergistic effect based on the effect of the heat insulating material and the effect of the cooling means.

  As described above, the press working apparatus in the die quench method of the present invention is for press-molding and quenching a heated steel material with a pair of upper and lower molds, and there are a plurality of lower molds on which the steel material is installed. Since these block dies are mounted on the base with a gap between adjacent block dies, even when continuous production is performed, the lower dies are divided into block types. Thermal expansion and contraction can be suppressed, and even if the lower mold expands slightly due to thermal expansion, the amount of extension can be absorbed by the gaps between the block molds, and interference between the upper mold and the lower mold at the cut portion Therefore, excision processing such as drilling and trimming can be performed smoothly for a long time simultaneously with press molding. Therefore, according to the press working apparatus of the present invention, a steel material can be continuously processed without increasing the number of processes by a relatively inexpensive mold structure, and high-quality products can be mass-produced and the production cost can be reduced. Can be made.

  Further, in the present invention, if a plate-like heat insulating material is disposed between the block mold and the base, it can be blocked by the interposition of the heat insulating material sandwiching heat from the steel material and the lower mold, to the base. Heat transfer can be prevented or suppressed, and the adverse effect on the cut part of the upper mold and lower mold caused by the thermal expansion of the base can be surely prevented, and the productivity can be increased by continuous production over a longer period of time. Can do.

  Furthermore, in the present invention, if the base is provided with a cooling means for cooling the base, the base can be effectively cooled. Depending on the cooling performance of the cooling means, the thermal expansion of the base can be achieved without providing a heat insulating material. Can be prevented or suppressed, and the same effect as the above-described invention can be obtained. Moreover, when a heat insulating material is provided, the thermal expansion of the base can be more reliably prevented or suppressed by the synergistic effect of the heat insulating material and the cooling means.

Hereinafter, the press working apparatus in the die quench method of the present invention will be described in detail based on the embodiment with reference to the drawings.
FIG. 1 is a plan view of a press working apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG. FIG. 1 shows a state in which the product is placed on a lower mold attached on the base of the press working apparatus.

As shown in FIGS. 1 and 2, a press working apparatus according to an embodiment of the present invention includes a press die 1 used in a die quench method, and the press die 1 is arranged so as to be opposed to each other. The upper die (upper blade) 2 and the lower die (lower blade) 3 are a pair of molds. The upper mold 2 is mounted on the lower surface of the apparatus main body of a press working apparatus (not shown), and the lower mold 3 is disposed and attached on the base 4 of the press working apparatus. In the press working apparatus of this embodiment, the apparatus main body is connected to an operating rod of a drive cylinder (not shown) and can be moved up and down, and the base 4 is fixed to a floor or the like (not shown). Further, the clearance c amount at the cut portion between the upper die 2 and the lower die 3 where trimming or other cutting is performed is set to about 10% of the thickness of the steel material (steel plate) that becomes the product 5 after press molding. For example, when the thickness of the product 5 is 2 mm, the clearance c amount on one side is 0.2 mm.
The upper mold 2 and the lower mold 3 constituting the press mold 1 are provided with a cooling water jacket (not shown) and the like, and by circulating the cooling water through the cooling water jacket, the press mold is provided. 1 is cooled so that it may become relatively low temperature with respect to the heated high temperature steel material used as the product 5. As shown in FIG.

  The lower mold 3 of this embodiment is divided into a plurality of block molds 31 as shown in FIG. That is, in the press die 1 of the present embodiment, the intermediate portion excluding both end portions in the longitudinal direction (left and right direction in FIG. 2) of the lower die 3 is divided into five block dies 31. These block molds 31 are each mounted on the base 4 by bolting or the like with a gap 32 between adjacent block molds 31, and are fixed along the longitudinal direction of the lower mold 3. They are arranged side by side at intervals. The sizes of the gaps 32 are determined according to the thermal expansion amount of the lower mold 3 and the like, and are set to a size that can absorb the thermal expansion amount of the lower mold 3.

  Further, as shown in FIG. 2, a plate-like heat insulating material 33 is disposed between the lower surface of the block mold 31 according to the present embodiment and the upper surface of the base 4. The heat insulating material 33 is formed using a ceramic material or the like, and the thickness of the heat insulating material 33 is such that heat from the heated high-temperature steel material and the lower mold 3 is blocked and transmitted to the base 4. Is set to

Next, a method for producing the product 5 by the die quench method using the press die 1 of the press working apparatus according to the embodiment of the present invention will be described.
First, the plate-shaped steel material used as the product 5 is heated to the quenching temperature of about 900 degreeC with the heating furnace of a pre-process. Next, the heated steel material is transported to the installation location of the press die 1 of the present embodiment, introduced between the upper die 2 and the lower die 3 that are opened, and placed on the lower die 3. Install (see FIG. 1 and FIG. 2). In this state, the apparatus main body (not shown) is driven by a drive cylinder (not shown), the upper die 2 is lowered toward the lower die 3, and the press die 1 is closed. Then, the steel material sandwiched between the upper mold 2 and the lower mold 3 is press-formed into a predetermined shape, and at the same time, a predetermined portion is drilled and unnecessary ends on both the left and right sides in the longitudinal direction are trimmed. And excised. Further, the steel material is quenched and quenched by the relatively low temperature upper mold 2 and lower mold 3. Thereafter, the apparatus main body (not shown) is driven by a drive cylinder (not shown), and the upper die 2 is raised to be separated from the lower die 3 and the press die 1 is opened. The necessary excision can be made and the hardened product 5 can be removed.

When such a process is repeated and the product 5 is continuously produced, the temperature of the lower mold 3 of the press mold 1 rises to about 100 ° C. However, since the lower mold 3 of the present embodiment is divided into a plurality of block molds 31 and has gaps 32 between the block molds 31, the block mold 31 constituting the lower mold 3 expands. Even if it does, interference with the upper mold | type 2 and the lower mold | type 3 does not generate | occur | produce in a cutting part, but continuous production is attained. In addition, since the heat insulating material 33 is interposed between each block mold 31 and the base 4, the base 4 does not thermally expand or hardly thermally expands.
For example, when the block mold 31 of this embodiment is 100 mm per piece, even if the temperature of the lower mold 3 is about 100 ° C. (Δθ = about 80 ° C.), the expansion of the lower mold 3 is calculated from the above-described calculation formula. The amount is 0.095 mm, and if the gap 32 of each block mold 31 is 0.2 mm or more, the upper mold 2 and the lower mold 3 do not interfere with each other.

  Thus, according to the press working apparatus of the embodiment of the present invention, the lower mold 3 of the press mold 1 is divided into the plurality of block molds 31 and the gaps 32 are provided between the block molds 31. Without increasing the number of processes, the steel material that will be the product 5 continuously is press-molded, and at the same time, excision processing such as drilling and trimming can be performed, and the necessary quenching can be performed, and the high-quality product 5 is mass-produced. be able to.

  Furthermore, in the press working apparatus of the present embodiment, the base 4 has a structure that does not thermally expand or is difficult to thermally expand due to the heat insulating material 33 interposed between each block mold 31 and the base 4. It is possible to reliably perform continuous production of the product 5 over a long period of time, and it is possible to improve productivity and reduce production costs.

FIG. 3 is a press working apparatus according to another embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG. FIG. 3 is a modification of FIG.
The base 4 in this embodiment is provided with a cooling means 41 for cooling the base 4 in place of the heat insulating material 33 in the above embodiment. The cooling means 41 includes a large number of pipes 41 a that are piped inside the large base 4 compared to the lower mold 3, and is configured to circulate cooling water through the pipes 41 a. These pipes 41a are connected to a pump and a cooling water supply source (not shown). The other structure is the same as that of the said embodiment, and the same site | part is shown with the same code | symbol.

  According to such another embodiment of the present invention, since the large cooling means 41 for cooling the base 4 is provided in the large base 4 compared to the lower mold 3, Even if heat from the block mold 31 of the mold 3 is transferred to the base 4, the large cooling means 41 can cool the base 4 quickly and effectively, and the top of the cutting part can be obtained without providing a heat insulating material. Interference between the mold 2 and the lower mold 3 can be prevented.

  While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.

For example, in the press working apparatus of the above-described embodiment, the heat insulating material 32 is interposed between the block mold 31 of the lower mold 3 and the base 4, or the cooling means 41 is provided on the base 4, and the base 4 However, when the amount of thermal expansion of the base 4 is small due to the length of the steel material to be the product 5 or the heating temperature, the heat insulating material 32 and the cooling means 41 are used. The thermal expansion and contraction of the lower mold 3 may be absorbed by the gaps 32 of the respective block molds 31. On the contrary, both the heat insulating material 32 and the cooling means 41 may be provided. The cooling means 41 may be reduced in size without increasing in size.
In addition, the middle part of the lower mold 3 excluding both end parts in the longitudinal direction is divided into 5 and is composed of 7 block molds 31. The number of block molds 31 to be divided is appropriately selected according to the length and material of the steel material. Is possible.

It is a top view which concerns on embodiment of this invention, and shows the press work apparatus in the die-quenching method. 1 shows a press working apparatus according to an embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG. 1 shows a press working apparatus according to another embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG. It is a top view which shows the conventional press work apparatus in the die quench method. FIG. 5 shows a conventional press working apparatus in the die quench method, and is a cross-sectional view taken along line BB in FIG. 4.

Explanation of symbols

1 Press Die 2 Upper Die 3 Lower Die 4 Base 5 Product 31 Block Die 32 Gap 33 Heat Insulation Material 41 Cooling Means

Claims (3)

A press working apparatus in a die quench method for quenching and heating a heated steel material with a pair of upper and lower molds,
The lower mold for installing the steel material is divided into a plurality of block molds, and these block molds are mounted on the base in a state where a gap is provided between adjacent block molds. Press processing equipment.   The press working apparatus according to claim 1, wherein a plate-like heat insulating material is disposed between the block mold and the base.   The press working apparatus according to claim 1 or 2, wherein the base is provided with a cooling means for cooling the base.

Images