JP5835562B2 - Rolling method of die casting - Google Patents

Description

The present invention relates to a method for rolling an aluminum alloy die casting.

  Aluminum alloy die castings are difficult to roll (plastic working) due to the mechanical properties of the material and the chill layer formed on the surface. Thus, for example, Patent Document 1 discloses a technique for changing the mechanical properties of a material by manipulating the composition of the material (aluminum alloy), but improves the workability (rollability) during rolling. On the other hand, there is a problem in castability.

Japanese Patent Laid-Open No. 11-80872

Therefore, the present invention has been made in view of the above circumstances, and provides a die casting casting rolling method capable of improving workability during rolling without manipulating the composition of the die casting casting made of aluminum alloy. It was made as an issue to do.

In order to solve the above-mentioned problems, the die casting casting rolling method of the present invention is such that residual heat that is lower than the recrystallization temperature and is 50 ° C. or higher is stored until it is taken out from the die casting mold and cooled to room temperature. The aluminum alloy die casting is rolled.

(Aspect of the Invention)
In the following, aspects of the invention that is recognized as being capable of being claimed in the present application (hereinafter referred to as claimable invention) will be exemplified, and each exemplified aspect will be described. Here, as in the claims, each aspect is divided into paragraphs, numbers are assigned to the respective paragraphs, and the descriptions of other paragraphs are cited as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combination of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiment, etc., and as long as the interpretation is followed, another aspect is added to the aspect of each section. Moreover, the aspect which deleted the component from the aspect of each term can also be one aspect of the claimable invention.
In the following items, each of the items (1) to ( 3 ) corresponds to each of claims 1 to 3 described in the claims.

(1) Rolling is performed on a die-cast casting made of an aluminum alloy in which residual heat lower than the recrystallization temperature and stored at 50 ° C. or higher is taken out from the die casting mold and cooled to room temperature. A die-casting rolling method characterized.
According to the die-casting rolling method described in this section, the remaining heat lower than the recrystallization temperature and not lower than 50 ° C. is sufficient until it is taken out from the die-casting mold and cooled to room temperature (generally 20 ° C.). By rolling the aluminum alloy die-cast casting that has been stored in the heat, the workability during rolling (rollability) can be improved. As a result, the aluminum alloy die-cast casting can be manufactured with high accuracy. Rolling can be applied.
In the aspect of this section, the timing for rolling the die-casted casting may be any timing as long as the temperature of the die-casting is within a predetermined range, and appropriately determined according to the die-casting (heat storage property). Can do. For example, in the case of a die-cast casting having a relatively large thickness and weight (high heat storage property), it takes time to cool to room temperature. The casting can be rolled. On the other hand, in the case of a die casting having a relatively small thickness and weight (low heat storage property), the die casting can be rolled before being taken out of the die casting mold and submerged and cooled.
For example, when a female thread (for example, M6) is rolled into a die-cast casting made of an aluminum alloy, by adopting this rolling method, rolling without using a lubricant dedicated to rolling, that is, rolling. It is possible to obtain the workability (rollability) during rolling equivalent to the conventional method of rolling into a die casting at room temperature (20 ° C) by lubricating with a dedicated lubricant. An internal thread having the same accuracy (quality) as that of the conventional method using the above lubricant can be obtained by dry processing.
Therefore, according to this rolling method, the use of a lubricant can be abolished, and the cost required for waste liquid treatment can be reduced.
In the embodiment of this section, when rolling an aluminum alloy die casting, the temperature of the die casting at the time of rolling is lower than the recrystallization temperature of aluminum, and the aluminum does not adhere to the rolling tool. It is desirable to set.

( 2 ) The die casting casting method of (1 ) , wherein a release agent is used for lubrication during rolling.
When using this rolling method to roll an internal thread to an aluminum alloy die-cast casting, using a mold release agent for lubrication is equivalent to using a rolling-only lubricant. Workability (rollability) can be obtained, and as a result, an internal thread with accuracy (quality) equivalent to that of the conventional method using a lubricant exclusively for rolling can be obtained. Furthermore, by setting the temperature of the die casting to 50 ° C. or higher, it is difficult to obtain good workability when using a lubricant exclusively for rolling. In addition, it is possible to obtain excellent processability (rollability) at the time of rolling, and it is possible to process a high-precision female screw by rolling with a die-cast casting made of an aluminum alloy. In addition, the use of oil-based lubricants is restricted due to environmental problems, but usually a relatively large die-casting facility is equipped with a release agent treatment facility. By using the same release agent (oil-based) as the release agent applied to the die-cast mold as a lubricant, oil-based release with excellent lubricity can be achieved with existing equipment without introducing new waste liquid treatment equipment. The mold can be used as a lubricant during rolling.
In the aspect of this section, as a method of supplying the release agent to the rolling tool or the pilot hole, a method of spraying the release agent from a nozzle operated by a robot, a method of spraying directly by an operator, and the like can be considered. An appropriate method may be selected depending on at which point (process) the rolling is performed. In addition, when forming a pilot hole for female threads during die casting, most of the release agent applied to the die cast mold is transferred to the die cast casting taken out of the die cast mold, so supply to the release hole of the release agent is omitted. It is also possible to do.

( 3 ) The die casting casting method according to (1) or (2) , wherein the die casting is subjected to rolling in a step of shaping the die casting, and the rolling operation is synchronized with the shaping operation.
According to the die-casting rolling method described in this section, it is possible to perform rolling simultaneously in the process of shaping the die-casting, and the manufacturing process can be rationalized.
In the aspect of this section, the step of shaping the die-casting is, for example, a step of removing a casting plan (pouring system) by a trimming die attached to a press machine (trimming step), or attached to a press machine This is a process (correcting process) for removing the distortion of the die-casting with a correcting die.
For example, when using this rolling method to roll a female thread to a die casting made of aluminum alloy in the trimming process (shaping process), a rolling device (rolling tapping machine) is installed on the upper mold of the trimming mold. The tapping operation (rolling operation) is synchronized with the upper die lifting operation (shaping operation). Thereby, the rolling process can be incorporated into the shaping process, and the manufacturing process can be rationalized. Similarly, when the rolling process is incorporated in the straightening process (shaping process), the rolling device may be disposed in the upper mold of the straightening mold. Further, when it is difficult to synchronize the rolling operation with the shaping operation, the shaping operation and the rolling operation may be separated, that is, the shaping and the rolling may be performed by two motions of the press machine.
Also, when removing a casting plan of a die casting using an NC processing machine, a female tool is rolled into the die casting in the same process by attaching a rolling tool to the spindle of the processing machine with a normal tool change. Can do.

  ADVANTAGE OF THE INVENTION According to this invention, the rolling method of the die-casting which can improve the workability at the time of rolling can be provided, without manipulating the composition of a die-casting.

It is explanatory drawing of this embodiment which shows the aspect which has arrange | positioned the rolling apparatus to the upper type | mold of a trimming type | mold. Under each processing condition, when an M6 female screw is processed by rolling into each pilot hole with a pilot hole diameter of 5.2 mm, 5.4 mm, and 5.6 mm of a die cast casting made of an aluminum alloy (ADC12), It is the chart which compared the possibility of each workability.

  An embodiment of the present invention will be described with reference to the accompanying drawings. In the present embodiment, a method will be described in which an M6 female thread is processed by rolling into a die-cast casting 1 made of an aluminum alloy (ADC12). In this rolling method, the die-casting is performed by rolling the die-casting 1 in a state where the residual heat at the time of die-casting is sufficiently stored until it is taken out from the die-casting mold and cooled to room temperature (generally 20 ° C.). 1, the internal thread can be rolled with high accuracy.

  After the die casting 1 is taken out from the die casting mold, it is submerged and cooled in the cooling step. A plurality of pilot holes for rolling an internal thread are formed in the die casting 1 when taken out from the die casting mold. Then, in the die cast casting 1 after being submerged and cooled, the casting plan 2 (pouring gate system) is removed in the trimming step. In the trimming process, the die-casting 1 is set between the upper mold 4 and the lower mold 5 of the trimming mold 3 attached to the press. In the present embodiment, the temperature of the die casting 1 set in the trimming die 3 is 50 ° C.

  As shown in FIG. 1, a rolling device 6 is disposed on the upper die 4 of the trimming die 3 at a position corresponding to each prepared hole of the die casting 1. Each rolling device 6 has a servo motor 8 for rotating forward / reversely the rolling tap 7 (rolling tool) held by the tool holder. Then, by adopting a servo press machine capable of motion control in the press machine, the normal / reverse rotation (rolling operation) of the rolling tap 7 is synchronized with the lifting / lowering operation (shaping operation) of the upper die 4, Trimming and rolling of the female thread are performed simultaneously in one motion of the machine. In this embodiment, as the lubricant for rolling, the same release agent as that applied to the die-cast cavity surface is directed from the nozzle attached to the arm type robot to each pilot hole. Supplied (injected).

Next, the operation of this rolling method will be described.
The chart shown in FIG. 2 shows each pilot hole with a diameter of 5.2 mm, 5.4 mm, and 5.6 mm of a die cast casting 1 (see FIG. 1) made of an aluminum alloy (ADC12) under each processing condition. In addition, the feasibility of each workability when the M6 female thread is processed by rolling is compared. In the figure, ◯ indicates that aluminum is not attached to the rolling tap 7 and the workability is good, and x in the figure indicates that the workability is poor.

Each processing condition A to G is as follows.
(1) Processing condition A
This is a condition corresponding to the prior art, in which a female screw is rolled into the die casting 1 at room temperature (20 ° C.) by dry processing (without using a lubricant and a release agent).
(2) Processing condition B
This is a condition corresponding to the present rolling method in which a female screw is rolled into the die cast casting 1 at 50 ° C. by dry processing.
(3) Processing condition C
This is a condition corresponding to the conventional technique in which the internal thread is rolled by lubricating the die cast casting 1 at room temperature (20 ° C.) with a lubricant exclusively for rolling.
(4) Processing condition D
This is a condition corresponding to the present rolling method in which a die cast casting 1 at room temperature (20 ° C.) is lubricated with a water-soluble release agent to roll a female screw.
(5) Processing condition E
This is a condition corresponding to the present rolling method in which the die cast casting 1 at 50 ° C. is lubricated with a water-soluble mold release agent and the female thread is rolled.
(6) Processing condition F
This is a condition corresponding to the present rolling method in which a die cast casting 1 at room temperature (20 ° C.) is lubricated with an oil-based mold release agent to roll a female screw.
(7) Processing condition G
This is a condition corresponding to the present rolling method in which the die cast casting 1 at 50 ° C. is lubricated with an oil-based mold release agent to roll a female thread.

  Comparing the processing condition A and the processing condition B, the temperature of the die casting 1 at the time of rolling is set to 50 ° C. It can be seen that good workability can be obtained even in the hole. Further, when the processing conditions B and C are compared, the temperature of the die-casting 1 is set to 50 ° C., so that a dry rolling lubricant is used in the die-casting 1 at room temperature even in dry processing. It can be seen that processability equivalent to that obtained by rolling is obtained.

  Furthermore, from the results of the processing conditions D and F, even in the case of the die-cast casting 1 at room temperature, a lubricant dedicated to rolling can be obtained by using an aqueous or oil-based mold release agent as a lubricant during rolling. It can be seen that an internal thread with the same accuracy (quality) as that obtained when rolled by use can be obtained. Then, from the results of the processing conditions E and G, other processing can be performed by using an aqueous or oil-based mold release agent as a lubricant at the time of rolling, and setting the temperature of the die casting 1 to 50 ° C. It can be seen that good workability can be obtained for rolling into a pilot hole with a pilot hole diameter of 5.2 mm, where good workability could not be obtained under the conditions.

This embodiment has the following effects.
According to the present embodiment, by rolling the die casting 1 in a state where the residual heat during die casting is sufficiently stored until it is taken out from the die casting mold and cooled to room temperature (generally 20 ° C.). The workability (rollability) at the time of rolling can be improved without manipulating the composition of the die casting 1, that is, without sacrificing the castability.

  And when rolling an internal thread to the die-casting casting 1 made from an aluminum alloy, the temperature of the die-casting casting 1 at the time of rolling is set to 50 ° C., so that dry processing, that is, without using a lubricant exclusively for rolling. Further, it is possible to obtain the workability (rollability) at the time of rolling equivalent to the case where it is lubricated with a lubricant exclusively for rolling and rolled into a die casting at room temperature (20 ° C.). As a result, it is possible to obtain a female screw having the same accuracy (quality) as that of the conventional method using a lubricant exclusively for rolling by dry processing. Thereby, the use of the lubricant can be abolished, and the cost required for the waste liquid treatment can be reduced.

  In addition, by using a mold release agent for lubrication during rolling, when rolling a female thread to a die-cast casting 1 made of aluminum alloy, the same processing during rolling as when using a lubricant exclusively for rolling. Therefore, it is possible to obtain a female screw having the same accuracy (quality) as that of a conventional method using a lubricant exclusively for rolling. In addition, by setting the temperature of the die casting 1 to 50 ° C. or higher, it is difficult to obtain good workability when a lubricant exclusively for rolling is used (for example, M6 pilot hole 5.2mm) can be obtained with good rolling processability (rollability), and high-precision female threads can be machined by rolling with die-cast aluminum alloy 1 Is possible.

  And, by using the same release agent as the release agent applied to the die-cast mold at the time of die-casting, an oil-based release agent with excellent lubricity is used as a lubricant for rolling in existing equipment. can do. Furthermore, when forming a pilot hole for a female thread during die casting, most of the mold release agent applied to the die cast mold is transferred to the die cast casting 1 taken out of the die cast mold. It can be omitted.

  In addition, the rolling operation of the rolling device 6 is synchronized with the raising / lowering operation (shaping operation) of the upper die 4 of the trimming die 3 (the ram of the press machine), thereby rolling in the trimming process (shaping process) of the die casting 1. Can be performed simultaneously, and the manufacturing process can be streamlined.

In addition, embodiment is not limited above, For example, it can comprise as follows.
In this embodiment, although the temperature at the time of rolling of the die-casting 1 was 50 degreeC, if it is temperature lower than the recrystallization temperature (150-250 degreeC) of aluminum, 70 degreeC may be sufficient, for example.
In this embodiment, the release agent supplied to the pilot hole as a lubricant at the time of rolling is sprayed by the nozzle. However, the operator may spray directly on the pilot hole or the rolling tap 7. In other words, an appropriate release agent supply method may be selected according to at which point (process) the rolling is performed.
If it is difficult to synchronize the rolling operation of the rolling device 6 with the raising / lowering operation (shaping operation) of the upper die 4 (the ram of the press machine) 3, the process is divided, that is, the first motion of the press machine. The trimming may be performed in the above and the rolling may be performed in the next continuous motion.
In the present embodiment, the case where the rolling is performed in the trimming process has been described. However, the timing for performing the rolling on the die casting 1 is within the range in which the temperature of the die casting 1 is determined in advance (for example, 50 to 70 ° C.). If it is, it may be at any timing and can be appropriately determined according to the die casting 1 (heat storage property). For example, if the die-casting 1 has a relatively large thickness and weight (high heat storage), it takes time to cool to room temperature, so the die-casting 1 is subjected to rolling in the appearance inspection process. Alternatively, in the case of the die-casting 1 having a relatively small thickness and weight (low heat storage property), the die-casting 1 before being taken out of the die-casting mold and submerged and cooled may be subjected to rolling. Furthermore, when removing the casting plan 2 of the die casting 1 using an NC machine, a rolling tool is attached to the main spindle of the machine by a normal tool change, and the female thread is transferred to the die casting 1 in the same process. You may make it.
In this embodiment, the rolling device 6 having the servo motor 8 is used to synchronize with the motion of the servo press. However, for example, a commercially available tapping unit may be combined with a clutch press.

1 Die Casting, 2 Casting Plan, 3 Trimming Die, 4 Upper Die, 5 Lower Die, 6 Rolling Equipment, 7 Rolling Tap (Rolling Tool), 8 Servo Motor

Claims (3)

Rolling is performed on a die-casting made of an aluminum alloy in which a residual heat lower than the recrystallization temperature and stored at 50 ° C. or higher is taken out from the die-casting mold and cooled to room temperature. A method for rolling die castings. Has been rolling method die cast according to claim 1, characterized in that the release agent to lubricate during rolling is used. The die-casting product according to claim 1 or 2 , wherein the rolling is performed on the die-casting product in a step of shaping the die-casting product, and the rolling operation is synchronized with the shaping operation of the die-casting product. Rolling method.

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