JP2014046362A - Distortion adjustment method of casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which distortion of a casting including a relatively low rigidity portion can be easily and surely adjusted, using simple constitution.SOLUTION: A distortion adjustment method of a casting 1 is provided for adjusting the distortion of the casting 1 including a relatively low rigidity portion LR and a high rigidity portion HR. In the method,, a large contraction amount adjusting casting plan 7a which has a relatively large contraction amount caused by a temperature drop to the ordinary temperature from a mold release is provided between a region of the relatively low rigidity portion LR being distorted so as to be deformed in a direction (upward in (a) of Fig.1) in which the portion separates from the high rigidity portion HR and the relatively high rigidity portion HR, and a small contraction amount adjusting casting plan 7b which has a relatively small contraction amount caused by the temperature drop to the ordinary temperature from the mold release is provided between a region of the relatively low rigidity portion LR being distorted so as to be deformed in a direction (downward in the (a) of the Fig.1) in which the portion approaches the high rigidity portion HR and the relatively high rigidity portion HR.

Description

  The present invention relates to a method for adjusting distortion of a casting, and more particularly, to a method for adjusting distortion of a casting including a relatively low rigidity portion and a high rigidity portion.

  For example, as shown in FIG. 7, when a casting 1 having a beam-like portion 5 that is separated from the bottom portion 2 and extends between both side wall portions 3 and 4 is integrally formed by casting, the rigidity of the beam-like portion 5 is increased. 8 is relatively low compared to the bottom portion 2 and the like (hereinafter, the beam-like portion 5 is also referred to as a low-rigidity portion LR, and the bottom portion 2 is also referred to as a high-rigidity portion HR). As shown, the beam-like portion 5 (relatively low-rigidity portion LR) is away from the original shape shown by the chain line in FIG. 8 away from the bottom portion 2 (relatively high-rigidity portion HR). A part that is distorted so as to be deformed and a part that is distorted so as to be deformed in a direction approaching the bottom part 2 are generated. As a result, the part may be deformed so as to be undulated and a casting having a target size may not be formed. . The reason why the relatively low-rigidity portion LR is deformed in this way is that the temperature unevenness of the entire casting 1 at the time of mold release or the amount of thermal shrinkage until the temperature of the casting 1 reaches room temperature varies depending on the portion. Can be mentioned.

  As a measure for adjusting the distortion of such a relatively low-rigidity portion LR, in order to reduce the temperature unevenness of the entire casting 1 at the time of mold release, it corresponds to a portion where the temperature drop of the casting 1 is slow. A mold cooling structure that can particularly cool the mold of the casting part, or a design that optimizes the wall thickness of the casting 1 so that the temperature unevenness of the casting 1 is reduced. For example, the shape of a casting is designed so as to increase rigidity.

  Furthermore, as another conventional technique, for example, as disclosed in Patent Document 1, in a casting obtained by cooling a molten metal poured into a mold, a thickness of a portion where the molten metal is easily radiated is increased. Further, there is disclosed a casting characterized in that the thickness is changed so that the thickness of the portion that is difficult to dissipate heat is reduced.

JP 2002-307138 A

  However, in the case of configuring the mold cooling structure among the above conventional techniques, in order to maintain the balance between the distortion adjustment of the relatively low-rigidity portion LR of the casting and the ensuring of the quality of the casting 1, As a measure for adjusting the distortion of the relatively low rigidity portion LR of the casting 1, there is a problem that the mold cannot be partially cooled sufficiently.

  Moreover, in the case of optimizing the thickness of the casting 1 among the above-described conventional techniques, it is possible to equalize the thickness by casting the thick portion, but the relatively low rigidity portion LR is reduced. There is a problem that there is a limit as a measure for adjusting to reduce distortion.

  Further, among the above conventional techniques, when the shape of the casting 1 is designed so that the rigidity of the casting 1 is increased, there is a problem that the weight of the casting 1 is increased.

  On the other hand, in the above-mentioned Patent Document 1, since the shape of a casting as a product is limited, there is a problem that it cannot be applied when a product having a uniform thickness is formed by casting.

  The present invention has been made in view of the above-described problems, and in a casting including a relatively low-rigidity part and a high-rigidity part with a simple configuration, the distortion of the relatively low-rigidity part can be easily performed. And it aims at providing the method which can be adjusted reliably.

  In order to achieve the above object, the invention according to the first aspect of the present invention relates to a method for adjusting the distortion of a casting including a relatively low-rigidity portion and a high-rigidity portion. Depending on the direction in which the low-rigidity part is distorted so as to be deformed with respect to the high-rigidity part, a shrinkage adjustment method with a different shrinkage quantity is applied between the relatively low-rigidity part and the high-rigidity part. It is characterized by providing in.

  According to the first aspect of the present invention, the contraction amount adjustment schemes having different contraction amounts are relatively low in accordance with the direction of the tendency to deform with respect to the high rigidity portion of the relatively low rigidity portion. By providing it between the rigid part and the high-rigidity part, each shrinkage adjustment method can be applied to a relatively low-rigidity part as the temperature decreases from the time of mold release to room temperature. Since the contraction is made in different amounts depending on the direction of the tendency to be distorted with respect to the rigid portion, the distortion of the relatively low-rigidity portion is reduced. Therefore, it is possible to easily and reliably adjust the distortion of the casting including the relatively low rigidity portion and the relatively high rigidity portion. In addition, if each contraction amount adjustment method is unnecessary as a product, it can be excised after the temperature of the casting is lowered to room temperature.

In order to explain an embodiment of the method for adjusting a distortion of a casting according to the present invention, a shrinkage adjustment method having a different shrinkage tends to be distorted so as to be deformed with respect to a high-rigidity portion of a relatively low-rigidity portion. It is the elements on larger scale which showed the casting provided between the relatively low-rigidity part and the highly rigid part according to this direction. It is the elements on larger scale shown in order to demonstrate the modification of embodiment shown in FIG. It is the perspective view shown in order to demonstrate the further modification of embodiment shown in FIG. FIG. 4 is a perspective view for explaining a further modification of the embodiment shown in FIG. 3. It is the perspective view shown in order to demonstrate 2nd Embodiment of the distortion adjustment method of the casting of this invention. It is the perspective view shown in order to demonstrate the modification of embodiment shown in FIG. It is the perspective view shown in order to demonstrate an example of the shape of the casting containing a relatively low rigidity part and a highly rigid part. FIG. 8 is a partially enlarged side view seen from the direction of arrow A in FIG. 7 in order to explain the distortion of the relatively low rigidity portion.

  One embodiment of the casting distortion adjusting method of the present invention will be described in detail with reference to FIGS. In the drawings, the same reference numerals denote the same or corresponding parts. As shown in FIG. 7, the shape of the casting 1 in this embodiment is that the bottom portion 2, both side wall portions 3 and 4 rising from opposite side edges of the bottom portion 2, the both side wall portions 3, 4 has a rear wall portion 6 rising from the rear edge of the bottom portion 2 adjacent to each other, and a beam-shaped portion 5 which is spaced from the bottom portion 2 and extends between the front sides of the side wall portions 3 and 4. Yes. The rigidity of the beam-like part 5 is relatively low compared to the bottom part 2. In this embodiment, it is assumed that the beam-like portion 5 corresponds to the relatively low-rigidity portion LR of the present invention, and the bottom portion 2 corresponds to the relatively high-rigidity portion HR of the present invention. .

The method for adjusting the distortion of the casting 1 of the present invention generally adjusts the distortion of the casting 1 including the relatively low-rigidity portion LR and the high-rigidity portion HR. Depending on the direction in which the high-rigidity portion HR is distorted so as to be deformed, the contraction amount adjustment methods 7a and 7b having different contraction amounts are placed between the relatively low-rigidity portion LR and the high-rigidity portion HR. Provided.
In more detail, the relatively distorted portion LR is deformed in a direction away from the highly rigid portion HR (upward in FIG. 1A) and the relatively highly rigid portion HR. Is provided with a large shrinkage adjustment method 7a that has a relatively large shrinkage amount due to the temperature drop from the time of mold release to room temperature, and approaches the high-rigidity portion HR of the relatively low-rigidity portion LR (see FIG. Small shrinkage adjustment between the part which is distorted to be deformed downward in (1) (a) and the relatively high rigidity part HR, which is relatively small in shrinkage due to the temperature drop from mold release to room temperature The usage plan 7b is provided.

  The beam-like portion 5 which is a relatively low-rigidity portion of the casting is caused by unevenness in temperature from the completion of molding to release to normal temperature as shown by the chain line in FIG. It will be distorted. The distortion of the beam-shaped portion 5 includes a portion that tends to be distorted in a direction away from the bottom portion 2 that is a relatively high-rigidity portion (upward in FIG. 1A), and a bottom portion. 2 and a portion that tends to be distorted so as to be deformed in a direction approaching 2 (downward in FIG. 1A). The tendency in the direction of distortion due to this part can be grasped in advance by an empirical rule or simulation.

  Therefore, in this embodiment, a large contraction amount adjusting plan 7a is provided between the bottom portion 2 and a portion that tends to be deformed so as to be deformed in a direction away from the bottom portion 2 of the beam-shaped portion 5. A small contraction amount adjusting method 7b is provided between the bottom portion 2 and a portion that tends to be distorted so as to be deformed in a direction approaching the portion 2. Specifically, the large shrinkage adjustment method 7a has a relatively large cross section (that is, the dimensions in the width direction (left and right direction in FIG. 1) and depth direction (direction perpendicular to the paper surface in FIG. 1) in the cross section). (Relatively large), it is relatively easy to maintain the heat of the molten metal at the time of mold release (that is, it is easy to maintain a high temperature), and the amount of shrinkage accompanying the temperature drop to room temperature is relatively large (in FIG. 1B) (Refer to the length of the arrow shown in the large shrinkage adjustment method 7a). On the other hand, the small shrinkage adjustment method 7b specifically has a comparatively small cross section (that is, a width direction in the cross section (left-right direction in FIG. 1) and a depth direction (direction perpendicular to the paper surface of FIG. 1). The size is relatively small), and the heat of the molten metal is relatively easily released at the time of mold release (that is, the temperature tends to be low), and the amount of shrinkage due to the temperature drop to room temperature is relatively small ((b) in FIG. 1). (Refer to the length of the arrow shown in the small shrinkage adjustment method 7b). As used herein, “relatively high or low rigidity part” means that the rigidity is high or low when both parts are compared, and “relatively holds or releases the heat of the molten metal. “Easy to do” means that the change in the temperature of the molten metal is compared between the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b. Furthermore, “relatively” larger or smaller in terms of dimensions and shrinkage amounts means that they are relatively larger or smaller when the large shrinkage amount adjustment plan 7a and the small shrinkage amount adjustment plan 7b are compared.

  The large contraction amount adjusting method 7a and the small contraction amount adjusting method 7b are integrally formed through the beam-shaped portion 5, the bottom portion 2, and the fracture portion 8, respectively. The large contraction amount adjusting method 7a and the small contraction amount adjusting method 7b can have substantially the same length, but the lengths can be made different in order to adjust to an appropriate contraction amount.

  Next, based on the embodiment shown in FIG. 1, the operation of the large contraction amount adjusting plan 7a and the small contraction amount adjusting plan 7b will be described. When the molten metal filled in the mold cavity drops to a predetermined temperature and solidifies, the casting 1 is taken out of the mold by opening the mold (mold release). The temperature of the casting 1 decreases from the time of mold release to room temperature. At this time, as described above, the beam-like portion 5 that is a relatively low-rigidity portion generally tends to be distorted due to temperature unevenness of the casting 1 or the like. However, in a portion that tends to be distorted so as to be deformed in the direction away from the bottom portion 2 of the beam-shaped portion 5, the large shrinkage adjustment method 7 a is relatively heat-shrinked until it reaches room temperature, and the beam-shaped portion In the part which tends to be distorted so as to be deformed in the direction approaching the bottom part 2 of 5, the small shrinkage adjustment method 7b undergoes heat shrinkage relatively small by the time it reaches room temperature. That is, in the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b, there is a difference in the amount of thermal shrinkage due to a temperature drop from release to normal temperature (see FIG. 1B). See arrows with different lengths). Therefore, as shown in FIG. 1B, it is possible to adjust so as to reduce the distortion in the opposite direction of the beam-like portion 5 which is a relatively low-rigidity portion.

  The casting mold for forming the casting 1 having such a shape can form a casting plan such as a cavity having a shape corresponding to the shape of the casting 1 and a runner for introducing a molten metal into the cavity. What is necessary is just a thing, and a metal mold | die, a sand mold, etc. can be employ | adopted.

  Next, a modification of the embodiment shown in FIG. 1 will be described with reference to FIG. In this embodiment, parts that are the same as or correspond to those in the embodiment shown in FIG. 1 are given the same reference numerals and explanation thereof is omitted, and only different parts are explained.

  In this embodiment, not only a large shrinkage adjustment method 7a and a small shrinkage adjustment method 7b but also a temperature maintenance method 9 is provided. In the embodiment shown in FIG. 2, the temperature maintenance method 9 is provided adjacent to the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b. This temperature maintenance method 9 is formed in the beam-shaped part 5 which is a relatively low-rigidity part with a length that does not reach the bottom part 2 which is a relatively high-rigidity part. By forming the temperature maintenance plan 9, the beam-like portion 5 can delay the temperature drop after being released. For this reason, the beam-shaped portion 5 is subjected to a difference in thermal shrinkage between the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b in a state where the high temperature state is maintained after being released from the mold, and the distortion is reduced. It will be reduced.

  Next, a further modification of the embodiment shown in FIG. 1 will be described with reference to FIG. In this embodiment as well, the same or corresponding parts as those in the embodiment shown in FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.

  In this embodiment, means 11 for adjusting the temperature so as to cool or heat the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b as necessary is provided. In the embodiment shown in FIG. 3, by the flow path 11a for circulating the temperature adjustment medium formed so as to be in contact with the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b in the cavity of the mold. It is configured.

  Thus, by providing the temperature adjusting means 11 including the flow path 11a in the mold, not only the size of the cross section of the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b, but also the thermal shrinkage difference can be set when the mold is opened. It can be produced in any amount. Therefore, depending on the shape of the casting 1 or the like, there is a difference in cross section between the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b between the relatively low rigidity portion 5 and the relatively high rigidity portion 2. Even if there is a restriction on the mold to be attached, a large shrinkage adjustment method 7a and a small shrinkage adjustment method 7b are surely caused to cause a heat shrinkage difference, and the relatively low rigidity portion 5 Distortion can be reduced.

  Next, a further modification of the embodiment shown in FIG. 3 will be described with reference to FIG. Also in this embodiment, the same or corresponding parts as those in the embodiment shown in FIG. 3 are denoted by the same reference numerals, and the description thereof will be omitted, and only different parts will be described.

  In this embodiment, the temperature adjusting means 11 is constituted by a nozzle 11b that sprays a cooling medium or a heating medium on the large shrinkage adjustment method 7a and the small shrinkage adjustment method 7b, respectively.

  By providing the temperature adjusting means 11 including the nozzle 11b as described above, it is necessary or preferable to provide not only the embodiment shown in FIG. 3 but also the temperature maintenance method 9 shown in FIG. Even if the temperature maintenance method 9 cannot be provided due to the above, the heat shrinkage difference method 7a and the small shrinkage amount adjustment method 7b are surely caused to cause a difference in heat shrinkage and the relatively low rigidity portion 5 Distortion can be reduced.

  Next, a second embodiment of the casting distortion adjusting method of the present invention will be described in detail with reference to FIGS. Note that portions that are the same as or correspond to those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different portions are described.

  The shape of the casting 1 in this embodiment has a bottom portion 21 and both side wall portions 24 and 25 rising from opposite side edges of the bottom portion 21 and has a U-shaped cross section. And one side wall part 25 has relatively low rigidity. In this embodiment, one side wall portion 25 will be described as corresponding to a relatively low rigidity portion of the present invention. In this embodiment, the high-rigidity plan portion 22 is formed in addition to the portion constituting the product of the casting 1. The high-rigidity plan portion 22 has a relatively high rigidity with respect to the one side wall portion 25. In this embodiment, the high-rigidity plan portion 22 will be described as corresponding to the relatively high-rigidity portion of the present invention.

  The method for adjusting the distortion of the casting 1 in this embodiment is generally distorted so as to be deformed in a direction away from the high-rigidity plan portion 22 that is a high-rigidity portion of one side wall portion 25 that is a relatively low-rigidity portion. A large shrinkage adjustment method 7c having a relatively large shrinkage amount due to a temperature drop from the time of mold release to room temperature is provided between the portion and the high rigidity plan portion 22, and the high rigidity plan of one side wall portion 25 is provided. A small shrinkage adjustment method 7d is provided between the portion that is distorted so as to be deformed in a direction approaching the portion 22 and the high rigidity plan portion 22 with a relatively small shrinkage amount due to a temperature drop from the time of mold release to room temperature. It is.

  The high-rigidity plan portion 7c may be formed using a runner for introducing the molten metal into the cavity of the mold, or by a cavity formed according to the shape of the casting 1 and a cavity formed separately from the runner. It can also be molded.

Next, a modification of the second embodiment will be described with reference to FIG. In this embodiment, parts that are the same as or correspond to those in the above-described embodiment are denoted by the same reference numerals, description thereof is omitted, and only different parts are described.
In this embodiment, as in the embodiment shown in FIG. 5, one side wall portion 25 that is a relatively low-rigidity portion, and a high-rigidity plan portion 22 that is a relatively high-rigidity portion, The shrinkage adjustment methods 7c and 7d having different shrinkage amounts are provided according to the direction in which one of the side wall portions 25 is deformed. In this embodiment, each shrinkage adjustment method is further required. Accordingly, temperature adjusting means 11 for cooling or heating is provided.

  In this embodiment, the temperature adjusting means 11 for cooling or heating the shrinkage adjustment methods 7c and 7d as necessary is provided in the cavity of the mold 10 in the same manner as the embodiment shown in FIG. It is formed so as to be in contact with the large shrinkage adjustment method 7c and the small shrinkage adjustment method 7d, and is constituted by a flow path 11a for circulating the temperature adjustment medium. With this configuration, even when the mold 10 is constrained, the large shrinkage adjustment method 7c and the small shrinkage adjustment method 7d are surely caused to have a difference in heat shrinkage, so that the relatively low rigidity portion 25 Distortion can be reduced.

  The temperature adjustment means 11 for cooling or heating the shrinkage adjustment plans 7c and 7d as necessary is similar to the large shrinkage adjustment plan 7c as in the embodiment shown in FIG. It is also possible to employ a configuration in which a nozzle for spraying a cooling medium or a heating medium is provided on the small shrinkage adjustment method 7d. With such a configuration, even when the temperature maintenance method 9 (see FIG. 2) cannot be provided, the thermal contraction difference between the large contraction amount adjustment method 7c and the small contraction amount adjustment method 7d is reliably ensured. Thus, the distortion of the relatively low-rigidity portion 25 can be reduced.

  Further, the shape of the casting 1 described in the above-described embodiment is shown for explanation, and the present invention includes relatively low-rigidity and high-rigidity parts 5, 2, or 25, 22; Any casting can be used as long as these parts are separated from each other.

  1: casting, 2: bottom part (relatively high rigidity part), 5: (relatively small rigidity part), 7a, 7c: large shrinkage amount adjustment method, 7b, 7d: small shrinkage amount adjustment method 8: Breaking part, 9: Temperature maintenance plan, 11: Temperature adjusting means

Claims (1)

A method for adjusting distortion of a casting including a relatively low rigidity portion and a high rigidity portion,
Depending on the direction in which the relatively low-rigidity portion is distorted so as to be deformed with respect to the high-rigidity portion, the shrinkage-adjustment schemes having different shrinkage amounts are divided into a relatively low-rigidity portion and a high-rigidity portion. A method for adjusting the distortion of a casting, characterized by being provided between the two.

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