JP4786938B2 - Rotary cam shaft material and its continuous casting method - Google Patents

Description

  The present invention relates to a rotary cam shaft material for manufacturing a rotary cam shaft of a press mold part, and a manufacturing method thereof.

  A rotary cam mechanism is used in a press mold device (bending type) that press-shapes negative corners in metal panel parts such as automobiles, and the rotary cam shaft is used as a rotating shaft component that constitutes the rotary cam mechanism. There is. The cross-sectional shape is generally approximate although the details differ depending on the type of the cross-section, for example, a shape like a portion 11a indicated by a solid line in FIG. Such a rotary cam shaft is made of cast iron, and is conventionally processed from a rotary cam shaft material cast by a full mold method using a polystyrene foam model. The rotary cam shaft material obtained by the conventional full mold method has a large margin for machining on the entire surface in order to avoid casting defects on the surface. There is a problem that the problem of poor casting due to the nest occurs.

  Separately, conventional cast iron round bars, polygonal cross-section bars, and the like are manufactured by a continuous casting method that is advantageous in terms of manufacturing cost and uniform quality. The outline of the production is as follows. That is, a cast iron melt is accommodated in the tundish, a graphite die is arranged at the outlet of the melt provided in the tundish, the outer periphery of the die is cooled with a water cooling jacket, and the molten metal flowing out of the tundish is At least the entire outer peripheral portion is solidified while passing through the die, and the solidified portion on the outer periphery is solidified to the core portion while being moved so as to be pulled out by the moving means.

  It is conceivable to apply the above-mentioned continuous casting method in which sand bites or nests are hardly formed near the surface for casting of the rotary cam shaft material. However, using a continuous casting technique such as a conventional round bar or a polygonal cross-section bar, it has a circular notch cross-sectional shape in which a part of the outer peripheral surface of the round bar is roughly cut away like a rotary cam shaft. When trying to cast a bar, the temperature at which the bar is cooled becomes uneven at different positions in the circumferential direction in the cross section, and stable casting cannot be performed, causing surface cracks or breakouts was there. That is, it was difficult to obtain the rotary cam shaft material by continuous casting.

In order to improve the non-uniformity of the cooled temperature of the rotary cam shaft material at different positions in the circumferential direction during continuous casting, the distance from the outer peripheral surface of the graphite die to the inner hole is made uniform over the entire outer peripheral portion. it is conceivable to equalize all around the water cooling effect and thus the need to extend along the inner wall shape of the water-cooled jacket in the shape of the die outer peripheral surface, the cross-sectional shape differs from a die alone rather than water cooled di jacket However, another problem arises that must be prepared separately. In addition, with the rotary camshaft, it is difficult to obtain the uniformity of the outer peripheral surface temperature of the cast iron rod by simply cooling the entire circumference of the die bore, and the temperature at which the rod is cooled is different at different positions in the circumferential direction in the cross section. There are some problems that cannot be solved.
It is an object of the present invention to provide a rotary cam shaft material that is well cast and to provide a method capable of continuously casting the same.

Rotary cam shaft material of the present invention, the rotary cam shaft member having a generally concave cross-sectional shape of the concave do they shape and the notch shape with a notch in a part of a circle reaches the center of the circular And it is what was cast by the continuous casting method (Claim 1). Since it is continuously cast, there is no occurrence of sand or nests near the surface, and the machining margin when machining into a rotary cam shaft can be reduced. Further, since the a roughly configured to have a concave cross-section shape, the geometry of the cut out portion in the central portion is secured within a predetermined range in Russia Tarikamu shaft member, since the state of the vicinity of the surface is good The casting surface may be left as it is, and the machining of the center portion, which has conventionally been required, can be omitted, and the number of machining steps can be reduced.

Continuous casting method of the rotary cam shaft material of the present invention, dies, generally concave cross-sectional shape but concave do that and the notch portion in a shape has notches in a portion of a circle has reached the center of the circular A rotary camshaft having an inner hole corresponding to the cross-sectional shape of the rotary camshaft having a shape, a water cooling jacket disposed around the die to cool the die, and a cast iron melt flows into the die to be solidified and pulled out In the continuous casting method of material, the second cooling means different from the water cooling jacket is applied to the die to equalize the cooling of the peripheral surface portion of the inner hole of the die (Claim 2 ).

  By this means, the temperature of the peripheral surface portion of the drawn-out rotary cam shaft material can be equalized by compensating for insufficient cooling by the water cooling jacket of the inner peripheral surface portion of the die by another second cooling means, thus preventing breakout. The rotary cam shaft material can be continuously cast without any defects.

Further another, the die of the present invention, a rotary cam shaft having a generally concave cross-sectional shape of the concave do they shape and the notch shape with a notch in a part of a circle reaches the center of the circular In a continuous casting method of a rotary cam shaft material having an inner hole corresponding to the cross-sectional shape of the material, cooling the die by disposing a water cooling jacket around the die, and drawing the molten cast iron into the die while solidifying it The cooling state of the outer peripheral surface of the rotary cam shaft is equalized by injecting one or both of compressed air and mist-like water onto the high temperature portion of the outer peripheral surface of the rotary cam shaft pulled out from the die. It is characterized (Claim 3 ).

  With this means, the desired portion can be intensively cooled by jetting compressed air or mist-like water or both, so that the high temperature portion of the rotary camshaft drawn from the die is grasped in advance. By appropriately cooling the portion, the temperature of the peripheral surface portion of the drawn rotary cam shaft can be equalized over the entire circumference, so that breakout can be prevented and the rotary cam shaft can be continuously cast without any defects.

According to the first aspect of the present invention, since the rotary cam shaft material is cast by a continuous casting method, there is no casting defect near the surface, the machining margin can be reduced, and the machining man-hour can be reduced. Play.
The invention according to claim 2 has an effect of further reducing the number of machining steps.
The invention according to claim 3 can newly cast a high-quality rotary cam shaft material so that breakout does not occur, and in the existing cast iron rod continuous casting apparatus, a new apparatus for supplying refrigerant to the die and its refrigerant passage. The effect which can be easily implemented only by providing is produced.
The invention according to claim 4 is capable of continuously casting a high-quality rotary cam shaft material so that breakout does not occur, and additionally providing a die and an air or water injection nozzle in an existing cast iron bar continuous casting apparatus. There is an effect that can be easily implemented.

The rotary camshaft has a substantially concave cross-sectional shape having a shape with a notch in a part of a circle and a shape in which the notch is recessed, and the notch is in the substantially concave cross-sectional shape. circular in that the center portion has reached the eccentric part is to be used in the rotary cam shaft remains casting surface in the arc-shaped inner peripheral surface.

Continuous casting method of the rotary cam shaft material is die has a generally concave cross-sectional shape of the concave do they shape and the notch shape with a notch in a part of a circle reaches the center of the circular A series of rotary camshafts that have an inner hole corresponding to the cross-sectional shape of the rotary camshaft, place a water-cooling jacket around the die, cool the die, and draw the molten cast iron into the die while solidifying it In the casting method, the second cooling means different from the water cooling jacket is applied to the die to equalize the cooling of the inner hole peripheral surface portion of the die, and the temperature of the outer peripheral surface of the rotary cam shaft member drawn from the die is high. It is used in combination with equalizing the cooling state of the outer peripheral surface of the rotary cam shaft material by injecting one or both of compressed air and water on the spray to the part.

  The rotary cam shaft 11 of the present invention has a cross-sectional shape shown in FIG. 2, is cast by a continuous casting method, and is cast using the continuous casting apparatus shown in FIG. 1st Example of a rotary cam shaft material and its continuous casting method are described using FIGS. 1-3, FIG. FIG. 1 is an apparatus used for carrying out a continuous casting method of a rotary cam shaft 11 in which another second cooling means is applied to a graphite die portion, showing a schematic configuration of the apparatus, and a cast iron melt accommodated in a tundish 1 2 is provided with a die made of a heat-resistant material, for example, a graphite die 4 and a water-cooling jacket 5, and a support roller 6 and a drawing moving device 7 are provided along an extension line of the outlet 3. An inner hole 8 corresponding to the cross section of the rotary cam shaft material is provided, and for example, a cooling pipe 10 is embedded in the graphite die 4 as another second cooling means 9. The water cooling jacket 5 has a cooling water inlet 15 and an outlet 16. In this configuration, except for the inner hole 8 of the graphite die 4 and another second cooling means 9, it is almost the same as the conventional apparatus.

  As shown in an enlarged cross section in FIG. 3, the graphite die 4 has a cylindrical shape similar to the conventional one described above, and an inner hole 8 corresponding to the cross sectional shape of the rotary cam shaft 11 at the center thereof. Has been drilled. And the water cooling jacket 5 is provided so that an inner peripheral surface may contact the perimeter of the outer peripheral surface of the graphite die 4. The rotary cam shaft material 11 takes into account, for example, a margin 11b to be removed by machining on the rotary cam shaft 11a whose sectional view is shown in FIG. As shown in FIG. 1 and FIG. 3, another second cooling means 9 has a cooling pipe 12 embedded in a radial thick portion 12 generated by providing the inner hole 8 of the graphite die 4. For example, water is circulated through the inlet 13 and the outlet 14 as a refrigerant. Therefore, the cooling capacity can be adjusted by adjusting the amount of water flow. Without the second cooling means 9, the thick portion 12 has a long heat transfer distance, so that the inside thereof is insufficiently cooled, but this can be solved. The position, quantity, size, and the like of the illustrated cooling pipe 10 are conceptual and are appropriately determined at the design stage.

  In this embodiment, by providing the second cooling means 9, the temperature of the entire peripheral surface of the rotary cam shaft 11 cooled by the water cooling jacket 5 and the second cooling means 9 and drawn from the graphite die 4 is equalized. be able to. That is, by supplementing the shortage of cooling by the normal annular water-cooling jacket 5 with the second cooling means 9, the entire circumference of the drawn out rotary cam shaft 11 can be equalized. Therefore, the rotary cam shaft 11 can be continuously cast without defects so that breakout does not occur. In the obtained rotary cam shaft 11, when the margin 11b shown in FIG. 6 is removed by machining to form the rotary cam shaft 11, the arcuate surface 11c at the center is left as cast surface. Yes, so that machining of this part can be omitted.

  A second embodiment of the present invention will be described with reference to FIG. This embodiment is an apparatus used for carrying out a continuous casting method of a rotary cam shaft material in which another second cooling means is applied to a portion where the graphite die 4a is exited. FIG. 4 shows a schematic configuration of the apparatus. The main difference from the first embodiment is that a second cooling means 9a is provided in place of the second cooling means 9. In FIG. 4, the same parts as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted. As shown in FIG. 4, the second cooling means 9 a is provided with the nozzle 20 directed toward the high temperature portion of the entire circumference of the rotary cam shaft 11 immediately after being pulled out from the graphite die 4 a as compared with other portions, The water is jetted as air is jetted from the nozzle 20. That is, air and mist are injected to the rotary cam shaft 11. The relatively high temperature portion of the rotary cam shaft 11 is a portion that has been in contact with the thick radial portion 12 of the graphite die 4a, and is the lower portion in FIG. The second cooling means 9a can adjust the cooling capacity by adjusting the supply amounts of water and air.

  In this embodiment, by providing the second cooling means 9a, the high temperature portion of the rotary cam shaft 11 drawn out from the graphite die 4a is intensively cooled, and the temperature of the outer peripheral surface is equalized near the outlet. . Therefore, the rotary cam shaft 11 can be obtained without deterioration in quality so that breakout does not occur.

In the third embodiment, although not shown, the second cooling means 9a and the second cooling means 9a in the second embodiment are used together in the first embodiment.
Thus, when the surface temperature uniformity of the entire circumference of the rotary cam shaft 11 is not good at the position where the graphite die 4 is exited, the second cooling means 9a can be used to correct this. Further, the second cooling means 9a can be applied to a portion where the surface temperature is likely to rise due to the heat held inside after leaving the graphite die. Therefore, since the peripheral surface temperature is further equalized, cracking is suppressed, and breakout caused by reheating from the unsolidified portion at the center is reliably prevented.

  High quality rotary camshaft can be manufactured.

The apparatus used in the first embodiment of the present invention is a longitudinal side sectional view to indicate schematically. It is an axis perpendicular cross-sectional view of the rotary cam shaft material shown in the embodiment. It is a cross-sectional enlarged view of the water cooling jacket and graphite die of the same Example. It is a vertical side view which shows typically the apparatus used in 2nd Example of this invention. It is sectional drawing which shows the part used as the rotary cam shaft and the rotary cam shaft machined in the 1st or 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tundish 2 Cast iron molten metal 3 Outlet 4, 4a Graphite die 5 Water cooling jacket 6 Support roller 7 Pulling moving device 8 Inner hole 9, 9a Second cooling means 10 Cooling pipe 11 Rotary cam shaft 11a Rotary cam shaft 11b Taking off 11c Yen Arc-shaped part 12 Thick part 13 Inlet 14 Outlet 20 Nozzle

Claims (3)

The rotary cam shaft member having a generally concave cross-sectional shape of the shape's concave do that and the notch in the circular part of notch shape reaches the center of the circular, cast by a continuous casting method Rotary cam shaft material. Among the dice corresponds to the circular rotary cam shaft member cross-sectional shape generally has a concave cross-sectional shape of and the notch part to have notch shape concave do they shape reaching the center of the circular In a continuous casting method of a rotary cam shaft member that has a hole, cools the die by placing a water cooling jacket around the die, and draws the molten cast iron into the die while solidifying, separate from the water cooling jacket The second cooling means is applied to a die to equalize the cooling of the inner peripheral surface portion of the die. Among the dice corresponds to the circular rotary cam shaft member cross-sectional shape generally has a concave cross-sectional shape of and the notch part in a notch shape concave does it shape reaching the center of the circular In the continuous casting method of the rotary cam shaft material which has a hole, cools the die by arranging a water cooling jacket around the die, and draws the molten cast iron into the die while solidifying it, the die is drawn from the die. A rotary cam shaft material that equalizes the cooling state of the outer surface of the rotary cam shaft material by injecting one or both of compressed air and mist-like water onto the high temperature portion of the outer surface of the rotary cam shaft material. Continuous casting method.

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