JP2005342735A - Cold form-rolling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply make preventable of the development of crack in a ring-like product at the low temperature season, such as winter, without needing high cost, in a cold form-rolling apparatus for forming the ring-like product by cold-form-rolling a ring-like blank. <P>SOLUTION: In the cold form-rolling apparatus, in which the ring-like blank 10 composed of a special steel is charged into a rolling-mill 2 one by one by holding with a moving arm 11 and cold-form-rolled while spraying form-rolling liquid onto the ring-like blank and also, form-rolling liquid circulating system for circulating the form-rolling liquid, this apparatus arranges nozzles 17a, 17b for dividing the form-rolling liquid in the form-rolling liquid system and spouting so as to charge this ring-like blank into the rolling-mill after preheating by spraying the form-rolling liquid spouted from the nozzles onto the ring-like blank held with the moving arm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cold rolling apparatus for forming and expanding a ring-shaped material made of special steel into a ring-shaped product by cold rolling.

Patent Document 1 below discloses a method of manufacturing a deformed cross-sectional product by cold rolling to load a ring-shaped material into a rolling mill composed of a forming roll, a receiving roll, and a mandrel. Patent Document 2 below discloses a method of forming a ring-shaped product such as a bearing race by cold-rolling a ring-shaped material made of difficult-to-process special steel without generating cracks.
JP-A-3-268833 Japanese Patent Laid-Open No. 2001-9552

  By the way, in general, cold rolling is expected to expand the ring diameter and near net forming by pressing the material at room temperature and plastically deforming it, but cracks are generated because the material is work hardened by rolling. There is a problem that it is easy to make. In particular, low temperatures such as in winter are more sensitive to cracking because the temperature of the material is lower than 10 ° C, so the above-mentioned patents are used for special steels such as bearing steel and high carbon steel that are difficult to roll. Even if measures were taken by considering the composition of the material as described in Document 2, there was a risk of cracks occurring at low temperatures.

For this, it was considered to preheat the material by convection heating with hot air or radiant heating with an electric heater only at a low temperature, but it would be unprofitable because it costs equipment and increases processing cost There's a problem.
Accordingly, the present invention can effectively prevent the occurrence of cracks by adding a simple device to an existing cold rolling device without requiring almost any equipment cost.

  For this purpose, the cold rolling apparatus according to the present invention holds a ring-shaped material made of special steel on a moving arm, loads them one by one on a rolling mill, and applies a rolling solution to the ring-shaped material while performing cold rolling. In the cold rolling apparatus provided with a rolling liquid circulation system for circulating the rolling liquid, a nozzle for diverting and discharging the rolling liquid to the rolling liquid circulation system was provided and held by the moving arm The ring-shaped material is preheated by applying a rolling liquid discharged from the nozzle to the ring-shaped material, and loaded into a rolling mill.

  Further, in the cold rolling apparatus according to the present invention, a heater is provided in the rolling fluid circulation system, and when the temperature at which the ring-shaped material can be preheated is less than 10 ° C., the rolling fluid is preheated by the heater. It is characterized by that.

  In order to prevent lubrication and seizure during rolling, the ring-shaped material is formed by applying the rolling fluid of the rolling fluid circulation system originally provided in the cold rolling device to the ring-shaped material before rolling. Is preheated in a short time, and the occurrence of cracks during rolling is prevented. Therefore, it is possible to extremely easily prevent the occurrence of cracks at low temperatures such as in winter.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing an outline of the cold rolling apparatus, and FIG. 2 is a plan view thereof. In the figure, 1 is a pan in which a water-soluble rolling liquid is stored, 2 is a rolling mill provided in a space above the pan, and the rolling mill 2 is provided so as to be rotated by a motor 3. 4, a receiving roll 6 provided to be rotated by a motor 5, and a mandrel 8 provided to be moved forward and backward by a cylinder 7. 9 is a chute on which ring-shaped materials 10 are sent in a line from a material supply device (not shown), 11 is a moving arm that is suspended from above, and the moving arm is provided at the lower end of the moving arm. The ring-shaped material 10 on the chute 9 is gripped by the grip 12, and the ring-shaped material is conveyed to a position where the mandrel 8 can be inserted. Then, the cylinder 7 is operated to insert the mandrel 8 into the ring-shaped material 10 and push the housing 20 by the cylinder 19 so that the receiving roll 6 is pressed against the mandrel, and the molding roll 4 and the receiving roll are received by the motors 3 and 5. By rolling the roll 6 and bringing the forming roll 4 into pressure contact with the outer periphery of the ring-shaped material 10, the ring-shaped product 10a having a desired size is rolled. Note that this rolling usually takes ten or more seconds, but during that time, the moving arm 11 holds the next ring-shaped material 10 from the chute 9 and stands by immediately before the rolling mill 2.

  Reference numeral 13 denotes a circulation pump for sucking the rolling liquid stored in the pan 1 through the filter 13a. The liquid supply pipes 14a and 14b on the discharge side of the circulation pump are provided with nozzles 15a and 15b, respectively. By providing at the upper part of the rolling mill 2, a rolling liquid is applied from both sides toward the ring-shaped material during rolling to improve the lubrication of the rolling friction portion, and the ring-shaped material is cooled to prevent seizure. In addition, on-off valves 16a and 16b are provided in pipe lines branched from the liquid supply pipes 14a and 14b, respectively, nozzles 17a and 17b are provided at the ends of the on-off valves, respectively, and the rolling liquid discharged from the nozzles is supplied. The ring-shaped material 10 that is held by the moving arm 11 and is waiting just before the rolling mill 2 is hung on the ring-shaped material 10. Reference numeral 18 denotes an electric heater provided in the pan 1 for preheating the rolling liquid. The rolling liquid in the pan 1 takes heat during the rolling during operation and naturally becomes a warm temperature of about 25 to 30 ° C. even in the winter. Preheating is not necessary.

  Thus, by applying the rolling liquid to the ring-shaped material 10, the temperature of the ring-shaped material immediately rises to 10 ° C or higher, and the ring-shaped material that has reached 10 ° C or higher is loaded into the rolling mill 2. Therefore, even when forming difficult-to-roll special steel products such as bearing steel and high carbon steel without always generating cracks, the rate of occurrence of defective products due to cracks is reduced.

  FIG. 3 is a graph showing the result of measuring the time required to raise the temperature of the ring-shaped material 10 to 10 ° C. or higher. In this experiment, when heated by hot air or by radiant heating by an electric heater. Compared to the case, it was verified that applying the rolling liquid is the most efficient heating method with high heat transfer efficiency in this temperature range. Moreover, according to the present invention, since the forming liquid is always kept at an appropriate temperature by depriving the heat at the time of rolling, the temperature can be maintained extremely economically without requiring a heat source. In this temperature range, a stable function can be continued without deteriorating the lubrication performance.

  In addition, when the temperature of the rolling fluid is low at the start of operation in winter or the like, and the temperature at which the ring-shaped material can be preheated is less than 10 ° C., the heater 18 preheats the rolling fluid only at the beginning of the startup. However, in any case, the temperature of the formed liquid can be maintained at a very low cost.

In addition, since the cold rolling device is originally provided with a rolling fluid circulation system for circulating the rolling fluid, the rolling fluid can be easily ring-shaped simply by branching the discharge side and providing the nozzles 17a and 17b. Since it is hung on the material 10, the equipment cost can be kept very low. Further, when the preheating is not required, the on-off valves 16a and 16b may be closed, and the operation is very simple.

The front view which shows the Example of the cold rolling apparatus which concerns on this invention. The top view which shows the Example of the cold rolling apparatus which concerns on this invention. The graph which shows the temperature rising curve of a ring-shaped material.

Explanation of symbols

2 Rolling mill 10 Ring-shaped material 11 Moving arm 13 Circulating pump 14a, 14b Liquid supply pipe 16a, 16b Open / close valve 17a, 17b Nozzle 18 Heater

Claims (2)

  Rolling material made of special steel is held on a moving arm, loaded one by one on a rolling mill, cold rolled while rolling the rolling material, and the rolling fluid is circulated. In a cold rolling apparatus equipped with a liquid circulation system, a nozzle for diverting and discharging the rolling liquid to the rolling liquid circulation system is provided, and the rolling liquid discharged from the nozzle is applied to a ring-shaped material held by a moving arm. A cold rolling apparatus, wherein the ring-shaped material is preheated by loading and loaded into a rolling mill.   The cold rolling apparatus according to claim 1, wherein a heater is provided in the rolling fluid circulation system, and when the temperature at which the ring-shaped material can be preheated is less than 10 ° C, the rolling fluid is preheated by the heater.

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