1. Field of the Invention
The invention relates to a press apparatus that press-forms a steel sheet with a forming die, and a spray nozzle mounted to this press apparatus.
2. Description of Related Art
Typically, with vehicle parts and the like, a method for manufacturing a molded article by press-forming a steel sheet with a forming die is used. In this method, when press-forming a heated steel sheet, a method that involves quenching by cooling the steel sheet by spraying coolant onto the steel sheet from the forming die is employed. Therefore, a related press apparatus includes a supply passage that is provided inside a forming die and to which coolant is supplied, a spray hole that is communicated with the supply passage and is formed in a contact surface of the forming die that contacts the steel sheet, and a spray nozzle that is mounted to the spray hole. When coolant is supplied to the supply passage of the forming die when cooling the steel sheet, the coolant passes through the supply passage and is sprayed from the spray nozzle onto the steel sheet.
However, with the related press apparatus, a diffusion angle of the coolant from the spray nozzle is small so cooling efficiency is poor, which is problematic. To increase the diffusion angle of the coolant from the spray nozzle, it is necessary to increase the shape accuracy within the spray nozzle, which will lead to an increase in cost. In addition, when the shape accuracy within the spray nozzle is increased, the durability of the spray nozzle becomes a concern. Furthermore, 50 to 200 spray nozzles are used for one set of forming dies, so an increase in the cost of a single spray nozzle will greatly affect equipment costs.
Japanese Patent Application Publication No. 2007-229772 (JP 2007-229772 A) describes a hot forming die that press-forms a heated steel sheet (i.e., a compact), and cools the compact by spraying coolant onto it. This hot forming die includes a main supply passage through which coolant passes, a plurality of branch supply passages that branch off from the main supply passage and include spray ports that spray the coolant inside the die, and a nozzle member that is fixed to the spray port side of each of the branch supply passages, and limits the amount of coolant that passes through it using a passing hole through which the coolant passes.
However, with the hot forming die according to the invention described in JP 2007-229772 A, the diffusion angle of the coolant from the nozzle member is unable to be increased simply by fixing a nozzle member having a passing hole to the spray port, so the aforementioned problem is unable to be solved.
The invention provides a press apparatus and spray nozzle capable of increasing the diffusion angle of a liquid such as coolant.
A first aspect of the invention relates to a press apparatus including a forming die with which a steel sheet is press-formed and a spray nozzle mounted to a spray hole provided in the forming die, for spraying coolant toward the steel sheet. The spray nozzle includes a nozzle main body having a through-hole, and a diffusion member provided inside the through-hole. The diffusion member includes a diffusing portion that diffuses coolant that flows through the through-hole, by interfering with the coolant, and a retaining portion that retains the diffusion member inside the through-hole. Accordingly, a diffusion angle of a liquid such as coolant from the spray nozzle is able to be increased.
Various modes of the press apparatus and spray nozzle of the invention, as well as the operation thereof, will now be described in detail.
A first aspect of the invention relates to a press apparatus that press-forms a steel sheet with a forming die, and that includes a spray nozzle mounted to a spray hole provided in the forming die, for spraying coolant toward the steel sheet. The spray nozzle includes a nozzle main body having a through-hole, and a diffusion member provided inside the through-hole. The diffusion member includes a diffusing portion that diffuses coolant that flows through the through-hole, by interfering with the coolant, and a retaining portion that retains the diffusion member inside the through-hole. With this press apparatus, the coolant that flows through the through-hole of the nozzle main body interferes with the diffusing portion and is sprayed diffused along the diffusing portion. Also, the diffusion member is retained in the through-hole by the retaining portion so as not to slip out of the through-hole.
The diffusing portion may include a protruding portion that is integrally provided on an end portion of a rod-shaped portion inserted into the through-hole, and that protrudes radially outward from the rod-shaped portion. The coolant flows through an annular passage to the outside of the rod-shaped portion inside the through-hole, and the coolant that has flowed through the annular passage interferes with the protruding portion of the diffusion member and is sprayed diffused along an outer wall surface of the protruding portion.
The through-hole may include a large diameter hole within which the protruding portion is arranged, a small diameter hole into which the rod-shaped portion is inserted, and a tapered surface that is provided between the large diameter hole and the small diameter hole, and that increases in diameter toward the large diameter hole. With this press apparatus, coolant that has interfered with the diffusing portion of the diffusion member is sprayed smoothly diffused by flowing along the tapered surface provided on the through-hole.
The rod-shaped portion may be formed in a pair opposing each other, and the retaining portion may include a tapered portion that is unable to fit into the small diameter hole, and is provided on an end portion of each of the pair of rod-shaped portions, which is on a side opposite the protruding portion. With this press apparatus, the diffusion member will not slip out of the through-hole when coolant flows through the through-hole of the spray nozzle.
The protruding portion may include a circular portion that is generally circular when viewed from a side, and that is integrally provided on each end portion of the pair of rod-shaped portions. With this press apparatus, the protruding portion is able to be formed easily.
The end portion of the small diameter hole is formed with a tapered surface that increases in diameter toward an end surface of the nozzle main body. As a result, the tapered portion provided on the diffusion member is able to be housed easily.
The diffusion member may also be a split pin. The diffusion member may be substituted with a split pin that is an existing product, so the cost is able to be less expensive.
A second aspect of the invention relates to a spray nozzle mounted to a spray hole for spraying a liquid. This spray nozzle includes a nozzle main body having a through-hole, and a diffusion member provided inside the through-hole. The diffusion member includes a diffusing portion that diffuses liquid that flows through the through-hole by interfering with the liquid, and a retaining portion that retains the diffusion member inside the through-hole. With this spray nozzle, liquid that flows through the through-hole of the nozzle main body interferes with the diffusing portion and is sprayed diffused along the diffusing portion. Also, the diffusion member is retained inside the through-hole by the retaining member so as not to slip out.
The invention makes it possible to provide a press apparatus and a spray nozzle that increases the diffusion angle of a liquid such as coolant.
Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:
Modes for carrying out the invention will now be described in detail with reference to
The spray nozzle 10 includes a nozzle main body 11 that is formed in a cylindrical shape and has a through-hole 12, and a diffusion member 13 provided inside the through-hole 12 of the nozzle main body 11, as shown in
As shown in
Next, a method for forming the spray nozzle 10 by assembling the diffusion member 13 into the through-hole 12 of the nozzle main body 11 will be described. First, the diffusion member 13 that includes the pair of rod-shaped portions 21, and the circular portion 24 integrally provided on the downstream side end portion of the pair of rod-shaped portions 21, is prepared. At this time, the diffusion member 13 may be substituted with a split pin that is an existing product. Continuing on, the diffusion member 13 is inserted into the small diameter hole 17 of the nozzle main body 11 from the side with the pair of rod-shaped portions 21. When this is done, the circular portion 24 of the diffusion member 13 is housed inside the large diameter hole 16 so as to abut against the downstream end portion of the small diameter hole 17 of the nozzle main body 11 (i.e., so as to cover a portion of the downstream side opening of the small diameter hole 17), and each tip end portion (i.e., upstream side end portion) of the pair of rod-shaped portions 21 protrudes slightly from the upstream side end surface of the nozzle main body 11. Then, the tapered portions 25 are formed by crimping the tip end portions of the pair of rod-shaped portions 21 so that they spread out in the radial direction, using a tool, not shown, thus completing the manufacture of the spray nozzle 10.
Next, the operation of the press apparatus 1 according to the example embodiment of the invention will be described. First, a plurality of the spray nozzles 10 are prepared, and the spray nozzles 10 are attached by being screwed into the spray holes 7a provided in the upper die 3 and the spray holes 8a provided in the lower die 4. Then the steel sheet 2 that has been heated at approximately 900° C. is transported by a transport mechanism, not shown, to in between the upper die 3 and the lower die 4. Next, the upper die 3 is lowered, and a protruding portion 31 of the lower die 4 engages with a recessed portion 30 of the upper die 3 such that the steel sheet 2 is sandwiched in between. At this time, at the stage in which the upper die 3 is lowered to a forming intermediate position, coolant is supplied to the upper die supply passage 7 of the upper die 3 and to the lower die supply passage 8 of the lower die 4. Then the coolant is sprayed toward the steel sheet 2 from the spray nozzles 10 that are screwed into the spray holes 7a and 8a of the upper die 3 and the lower die 4. When the coolant passes through the spray nozzles 10, the coolant flows through an annular passage 28 between an outer wall surface of the pair of rod-shaped portions 21 of the diffusion member 13 and an inner wall surface of the small diameter hole 17. Some of the coolant that has flowed through the annular passage 28 interferes with the outer wall surface of the circular portion 24 of the diffusion member 13, and flows along the first tapered surface 18 of the through-hole 12, and is sprayed diffused from the large diameter hole 16, as shown by the arrows in
Next, coolant stops being supplied to the upper die supply passage 7 of the upper die 3 and the lower die supply passage 8 of the lower die 4 when the upper die 3 is lowered to bottom dead center. As a result, the steel sheet 2 is able to be press-formed in a hat-shape, as well as quenched.
As described above, the spray nozzle 10 used in the press apparatus 1 according to the example embodiment of the invention includes the nozzle main body 11 having the through-hole 12, and the diffusion member 13 provided in the through-hole 12. The diffusion member 13 includes the protruding portion 22 (i.e., the diffusing portion) that is arranged abutting against the downstream side end portion of the small diameter hole 17 of the through-hole 12, and interferes with the coolant from the small diameter hole 17, thereby diffusing the coolant. Consequently, when the coolant passes through the spray nozzle 10, some of the coolant that has flowed through the small diameter hole 17 of the through-hole 12 is sprayed diffused by it (i.e., the coolant) interfering with the protruding portion 22 (i.e., the circular portion 24) of the diffusion member 13. As a result, the diffusion angle is able to be larger than it is with a nozzle member provided in the related press apparatus, so the cooling efficiency of the steel sheet 2 is able to be improved.
Also, with the spray nozzle 10 used in the press apparatus 1 according to the example embodiment of the invention, the through-hole 12 of the nozzle main body 11 includes the first tapered surface 18 that increases in diameter toward the large diameter hole 16, between the large diameter hole 16 positioned on the downstream side and the small diameter hole 17 positioned on the upstream side. Therefore, the diffusion angle is able to be made as large as possible by the coolant that has flowed through the small diameter hole 17 and interfered with the protruding portion 22 (i.e., the circular portion 24) of the diffusion member 13, flowing along the first tapered surface 18.
In this example embodiment, a mode in which the spray nozzle 10 is used in the press apparatus 1 is employed, but the spray nozzle 10 may also be used mounted to a liquid-spraying spray hole of another apparatus.
Number | Date | Country | Kind |
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2013-118993 | Jun 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IB2014/000987 | 6/5/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2014/195792 | 12/11/2014 | WO | A |
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Number | Date | Country |
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101394950 | Mar 2009 | CN |
1386668 | Feb 2004 | EP |
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02-191562 | Jul 1990 | JP |
05-140973 | Jun 1993 | JP |
2007-229772 | Sep 2007 | JP |
935166 | Jun 1982 | SU |
9519504 | Jul 1995 | WO |
9530488 | Nov 1995 | WO |
2013001630 | Jan 2013 | WO |
Entry |
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Partial English Translation of Office Action dated May 14, 2015 in Japanese Patent Application No. 2013-118993. |
Number | Date | Country | |
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20160114373 A1 | Apr 2016 | US |