JP4829575B2 - Manufacturing method of aluminum alloy forgings - Google Patents

Description

  The present invention relates to an aluminum alloy forged molded article and a method for producing the same, and more particularly to an aluminum alloy forged molded article including a step of forging a molded article having a groove-like portion parallel to the main molding direction. For example, the present invention relates to a method for manufacturing a rotor material of a rotary compressor for air conditioning mounted on an automobile or a rotor material of a rotary vacuum pump for brake control.

  As a molded product having a groove-like portion parallel to the main molding direction, there are a compressor rotor and a rotor of a rotary vacuum pump for brake control. The rotors of air-conditioning rotary compressors and brake-controlled rotary vacuum pumps mounted on automobiles are mainly made of aluminum alloy for the purpose of weight reduction. Usually, the rotor forging material has a shape in which a plurality of grooves for accommodating vanes are cut inward from the outer periphery of the cylindrical shape. Finally, this forging material is used for manufacturing a rotor by making a hole for inserting a shaft in the center by machining and performing machining for dimensioning.

  FIG. 14 is an example of a process for producing a rotor material by a conventional forging method. In the conventional method, as shown in FIG. 14A, an aluminum material cut into a predetermined length and heated is put into the bush 3 as a blank (forging material) 2. FIG. 14 (B) shows a state in which the pressing punch, which is the upper die 1 from above, descends a predetermined stroke for obtaining a required dimension in the longitudinal direction of the cylindrical shape, and the forming of the rotor material is completed. ing. Thereafter, as shown in FIG. 14C, the forged product is discharged from below by the knockout pin 8.

  As a method for producing this rotor material, a method by hot forging is known. For example, Japanese Patent Laid-Open No. 3-165948 discloses the following method.

  In the manufacturing method of an aluminum alloy rotor having a plurality of vane storage portions, the cross section perpendicular to the axial direction of the die hole is reduced or the same as the cross section perpendicular to the axial direction in the container, and arranged coaxially with each other. Using a die structure having a die and a container, a blank is inserted into the container, and the blank is pushed into a hole of a die having an outer contour shape of the rotor material by a pressure punch, and a die plate A manufacturing method of an aluminum alloy rotor is disclosed, in which the blank in the die hole backed up by the above is taken out through a container by a knockout punch in the die plate.

  However, with this forging method, it is difficult for the punch load to be transmitted near the corner portion of the lower end surface of the forged product, and it is difficult to completely fill the die with the material. Therefore, there is a problem that the groove width of the vane housing groove, which requires a shape accuracy, in particular, forged products is widened near the end face of the product. Therefore, it is necessary to obtain a forged product that is longer than necessary and cut the part where the groove width is widened, so that only the part having a predetermined shape is left as a product. , The material yield will deteriorate.

  In order to solve the above problems, for example, Japanese Patent Application Laid-Open No. 2000-117381 discloses the following forging method.

  (1) When an aluminum alloy rotor material having a vane storage groove is manufactured by a forging method, a convex portion is provided at a part corresponding to the side of the die blade part on the anvil located at the lower part of the die blade part forming the vane storage groove. A forging method characterized in that the groove width of the vane storage groove is corrected by forming a recess on the end of the vane storage groove on the end surface of the forged product, and (2) the total area of the protrusions is the end surface of the product The forging method according to the above (1), characterized in that the area is 30% or less, and (3) the position of the convex part is 4 mm or less from the die blade part (1) The forging method described in (2) and (4) the forging method described in (1) to (3) above, wherein the height of the convex portion is 0.3 mm or more and 3 mm or less. .

  On the other hand, there is a method in which a shaft insertion hole that has been machined after hot forging is forged together with a vane storage groove as a center hole by hot forging. Thereby, the cutting cost can be significantly reduced, and the yield of the forging material can be improved.

  However, when the center hole and the vane storage groove are forged together by the above hot forging, the forging material of the part formed as the center hole flows in the direction opposite to the molding direction, so the lower end surface of the forged product There is not enough forging material near the corner. Compared to the case where there is no center hole, it becomes difficult to fill the metal near the corner of the lower end surface of the forged product, and the groove width of the vane storage groove, which requires the shape accuracy of the forged product, is widened near the product end surface. Will occur. In principle, if the forging load is sufficiently high, it is possible to sufficiently fill the forging material near the corner portion of the lower end surface of the forged product, but in that case, the load applied to the die becomes excessive, There arises a problem that the life of the die is shortened and a problem that the die blade portion is deformed by a large load on the die and the dimensional accuracy of the vane housing groove is lowered.

  The present inventor investigated whether the groove width of the vane storage groove can be suppressed in the vicinity of the end face of the product by the method disclosed in Japanese Patent Application Laid-Open No. 2000-117381 in the rotor material having the center hole. I could not confirm. Even in this method, if the forging load is sufficiently high, the forging material can be sufficiently filled in the vicinity of the corner portion of the lower end surface of the forged product. However, there is a problem that the load on the mold is increased, the die life is shortened as described above, and the dimensional accuracy of the vane storage groove is lowered.

On the other hand, there is a back pressure forging method as a method for improving the tension of the shape of the end of the molded product. The back pressure forging method is used, for example, to uniformly fill the height of the blades of the scroll, and by rolling down the material while applying a load in the direction opposite to the forging direction to the tip surface of the material during forging, This is a technique that makes it possible to form a material tip that is difficult to transmit a load with high accuracy. For example, International Patent WO01-077398 discloses a forged scroll part and a method for manufacturing the same.
Japanese Patent Laid-Open No. 3-165948 JP 2000-117381 A International Patent Publication WO01-077398

  Also in the forging of the rotor material having the center hole, the material can be sufficiently filled in the vicinity of the corner portion of the lower end surface of the forged product by the back pressure forging method. However, the problem that the groove width of the vane storage groove widens near the end face of the product is solved, but on the other hand, it has been found that another problem has occurred if the back pressure method is simply applied. .

  There arises a problem that the deformation of the die blade portion of the mold is deformed in the direction perpendicular to the axial direction or twisted, and the positional dimensional accuracy of the vane housing groove is deteriorated. If the positional dimensional accuracy of the vane storage groove is deteriorated, it is necessary to perform cutting in order to ensure the predetermined dimensional accuracy, which also causes a problem that the material yield is deteriorated.

  In view of the above circumstances, the present invention improves the accuracy of the groove width dimension and the groove position dimension of the groove-shaped part when forging and manufacturing a molded product having the groove-shaped part in the main molding direction, and performs post-process cutting. The purpose is to omit processing and reduce processing man-hours.

The present invention provides the following means. That is,
(1) Forged aluminum alloy rotor material having a composition of 14 to 16% by mass of Si, 4 to 5% by mass of Cu, 0.45 to 0.65% by mass of Mg, and 0 of Fe .5% by mass or less, Mn is 0.1% by mass or less, Zn is 0.1% by mass or less, Ti is 0.2% by mass or less, and the remainder is Al and inevitable impurities. The width of the vane storage groove near the end face is not more than 50 μm without cutting the lower end surface so as to eliminate the inaccurate portion, and the center of the vane storage groove cylindrical portion of the upper end face and the lower end face An aluminum alloy forged molded product for producing a forged aluminum alloy rotor material having a vane storage groove parallel to the main molding direction, wherein the positional difference has a dimensional accuracy of 0.075 mm or less . A manufacturing method comprising: The main molding of the forging material includes the step of forging a forged molded article having a vane storage groove parallel to the main molding direction using a mold and a lower mold having a thin plate-like portion protruding into the molding hole. The groove width of the vane storage groove is started when the back pressure plate with back pressure applied to the front end surface in the direction stands by at a position higher than the vane storage groove forming part provided in the lower mold by 1 mm or more. In the die, the back pressure plate is freed by suppressing the spread in the vicinity of the product end surface and instantaneously removing the back pressure while the filling rate of the forging material into the forming hole is 10% to 55%. Made of aluminum alloy that releases high pressure applied to the blade and suppresses the deformation of the vane storage groove by suppressing the deformation and twisting in the direction perpendicular to the axial direction of the die blade. Manufacturing method for forged products.
(2) The upper die includes an upper die made of a pressure punch, and the filling rate is such that the length to the bottom dead center of the upper die at the start of molding is L, and a predetermined sliding angle of the upper die The method for producing an aluminum alloy forged molded product according to item 1 , wherein the length of the punch stroke is represented by [ΔL ÷ L × 100]%, where ΔL is ΔL.
(3) The upper mold includes an upper mold made of a pressure punch, and the filling rate is M when the length from the molding start time to the bottom dead center of the upper mold is M. 2. The method for producing an aluminum alloy forged molded product according to item 1 , wherein the length is represented by [ΔM ÷ M × 100]%, where ΔM is a punch stroke length.
(4) The method for producing an aluminum alloy forged molded article according to any one of items 1 to 3 , wherein the back pressure is instantaneously removed while the filling rate is 10% to 30%.
(5) back pressure is 2 kg / cm ² or more, any method for producing an aluminum alloy forged product according to one of the above 1 to 4, characterized in that a 7 kg / cm ² or less.
(6) The method for producing an aluminum alloy forged molded product according to any one of items 1 to 5 , wherein the back pressure is due to a hydraulic cushion and / or a gas cushion .
(7) The aluminum alloy continuous cast rod, the extruded material of aluminum alloy, the extruded material of powdered aluminum alloy, or any one of these rolled materials is used according to any one of the preceding items 1 to 6 as a forging material A method for producing a forged molded product made of aluminum alloy.
(8) The composition of the aluminum alloy uses a forging material in which Si is 14 to 16% by mass, Cu is 4 to 5% by mass, Mg is 0.45 to 0.65% by mass, and the remainder is Al and inevitable impurities. 8. The method for producing an aluminum alloy forged molded product according to any one of items 1 to 7 above.
(9) Fe is 0.5 mass% or less, Mn is 0.1 mass% or less, Zn is 0.1 mass% or less, and Ti is 0.2 mass% or less to the aluminum alloy composition of the forging material. manufacturing method of an aluminum alloy forged product as recited in claim 8, wherein the are.

Forged product having a forged molded according to the method of manufacturing the aluminum alloy forged product for producing aluminum alloy rotor material, parallel to the main forming direction vane accommodating grooves of the present invention described in (1) When forging is formed, the accuracy of the groove width dimension and the groove position dimension of the vane housing groove is improved, the subsequent cutting process is omitted, and the processing man-hours can be reduced to manufacture the aluminum alloy rotor .
According to the manufacturing method of the present invention described in (2) , the filling rate can be calculated in advance by the length of the punch stroke at the time of molding.
According to the manufacturing method of the present invention described in (3) , the filling rate can be calculated in advance by the length of the punch stroke at the time of molding.
According to the manufacturing method of this invention as described in (4) , the precision of the groove width dimension of a vane accommodation groove | channel and a groove position dimension can be improved more reliably.
According to the manufacturing method of the present invention described in (5) , the accuracy of the groove width dimension and the groove position dimension of the vane storage groove can be improved.
According to the manufacturing method of the present invention described in (6) , the accuracy of the groove width dimension and the groove position dimension of the vane storage groove can be improved by a simple method .
According to the manufacturing method of this invention as described in (7) , the precision of the groove width dimension of a vane accommodation groove | channel and a groove position dimension can be improved.
According to the production method of the present invention described in (8), it is excellent in wear resistance and strength, and a low thermal expansion coefficient is obtained. Suitable for use in air conditioning compressor parts mounted on automobiles.
According to the production method of the present invention as described in (9), it is excellent in wear resistance and strength, and a low thermal expansion coefficient is obtained. Suitable for use in air conditioning compressor parts mounted on automobiles.

For example, according to the method of the present invention, the spread of the groove width of the vane storage groove of the rotor is suppressed in the vicinity of the product end surface. For example, the maximum width of the groove width is 50 μm or less (preferably 15 μm or less, more preferably 10 μm or less. ), Preventing deterioration of the dimensional accuracy of the vane storage groove due to deformation or torsional deformation in the direction perpendicular to the axial direction of the die blade, for example, the difference between the upper and lower central positions of the vane storage groove cylindrical portion is 0.075 mm or less (Preferably less than 0.06 mm, more preferably 0.05 mm or less).
Preferably, the expansion of the groove width can be suppressed within a range of 5.5 mm from the outer periphery of the cylindrical portion of the vane storage groove toward the center.

  For this reason, dimensional accuracy within a predetermined range is obtained as a forged molded product, so that it is possible to omit the cutting processing of the forged product end face in the subsequent process or to reduce the amount of cutting, and to reduce the material input amount and the yield. And a rotor with good dimensional accuracy can be manufactured at low cost.

The present invention will be described in detail. Forged molded products having vane storage grooves in the main molding direction, which is the subject of the present invention, include a rotor of a compressor and a rotor of a rotary vacuum pump for brake control. The present invention will be described as an example.

  As shown in FIG. 1, the rotor 10 manufactured in the present invention has an outer periphery 11 of a cylindrical portion and a plurality of vane storage grooves 12 and a center hole 13 that penetrates the shaft in the axial direction.

  Usually, the forging material of the rotor 10 has a shape in which a plurality of vane storage grooves 12 for storing the vanes are cut inward from the outer periphery of the cylindrical shape. For example, the outer diameter of the cylindrical shape is 54 to 68 mm, the width of the vane groove is 2.8 to 3.1 mm, and the depth of the vane groove (the length of the groove in the center direction from the outer periphery of the cylindrical shape). The length in the longitudinal direction of the cylinder is 41.5 to 54.0 mm, and 31.5 to 44.0 mm.

Next, a die used in the present invention will be described by taking a back pressure forging die used for manufacturing the rotor 10 as an example. An exploded perspective view of the mold 14 used in the present invention is shown in FIG. The mold 14 includes an upper mold 15 and a lower mold 16, and the upper mold 15 includes an upper mold 15a including a pressure punch. The lower mold 16 fixes the lower mold 16a. Bush 16c having a through hole 16b for accommodating a forging material before forging, and a die for forming a vane accommodation groove 12 protruding inward from the wall surface of the molding hole 17 as shown in FIG. From the lower die 16a having five blade portions (vane storage groove forming portions) 18, a die B16d having a vane storage groove forming portion similar to the lower die 16a and capable of slidably storing the lower punch, from the press device A back pressure plate (lower punch) 16e to which back pressure is applied, a center pin 16f having a cylindrical protrusion for forming a center hole, a center pin 16f fixed by shrink fitting at the center position, and a through-hole for knockout pin penetration Die C16i and a 6h, transmits the back pressure to the lower punch from the press apparatus is configured to include a knockout pin 16g for yet taking out forged product from the mold.
In the present embodiment, the lower die 16a and the die B16d are divided for the purpose of dividing the mold, but may be integrated.

FIG. 4 is an example of a process of forging a rotor material by a forging method to which a back pressure is applied using the mold of the present invention. In the back pressure forging method of the present invention, first, the back pressure plate (lower punch) is placed at a position (Fig. 7, reference Z) higher than the vane storage groove forming portion of the forming hole 17 provided in the lower die 16a before the start of molding. ) 16e is waiting, and the back pressure is applied to the back pressure plate 16e via the knockout pin 16g.
It is preferable that the back pressure plate (lower punch) 16e is kept at a position higher by 1 mm or more because the back pressure is reliably and stably applied.
First, as shown in FIG. 4A, an aluminum material cut into a predetermined length and heated is put into a through hole of the bush 16c as a blank (forging material) 19. Next, the molding of the rotor material starts in a state where the pressure punch is lowered and the back pressure is applied from below by the back pressure plate (lower punch) 16e. FIG. 4B shows a state in the middle of molding in which the blank (forging material) 19 flows into the molding hole 17. When this state further proceeds and the filling rate of the forging material 19 into the forming hole of the lower die 16 is within a predetermined range, the back pressure is released. Thereafter, as shown in FIG. 4C, the punch of the upper die 15a is lowered by a predetermined stroke length to obtain a required dimension in the longitudinal direction of the cylindrical shape, and the forming of the rotor material is completed. And a forge molded product is discharged | emitted by the knockout pin 16g from the downward direction like FIG.4 (D).

The appearance of the upper mold 15a used in the present invention is shown in FIG. The upper mold 15a of the present invention is preferably a mold having a recessed portion 24 opposite to the operation direction of the upper mold at a position corresponding to the vane storage groove forming section as viewed from above the operation direction axis of the upper mold. An example of the external appearance of the forged molded product when using the metal mold | die 15a which has this recessed shape part 24 is shown in FIG. By having such a shape, the metal surplus portion 25 is attached to the portion of the forged molded product that contacts the pressure punch, and the metal flow in the vicinity of the die blade portion 18 is made free. As a result, in the vicinity of the vane storage groove 12 and the vicinity of the cylindrical protrusion, the direct load from the pressure punch can be absorbed by the metal portion, and the load due to the pressure punch can be reduced. As a result, there is an effect of suppressing deformation of the formation portion of the vane storage groove 12 and the center pin 16f, and the mold life can be extended.
Particularly, with respect to the vane storage groove 12, the depth of the recessed portion 24 is 0.5 to 3.5 times the width of the vane storage groove 12 (for example, the width of the vane storage groove is 3.0 mm, The depth of the recess-shaped portion 24 is 1.5 mm to 10.5 mm), and the width of the recess-shaped portion 24 is 1 to 3.5 times the width of the vane storage groove 12 (for example, the width of the vane storage groove 12 is 3.0 mm and the width of the recessed portion 24 is preferably 3.0 mm to 10.5 mm). In the method of the present invention, since the groove dimensional accuracy is improved mechanically, the volume of the recessed portion is larger than that of the conventional method. Thus, the material yield can be improved.

An example of an embodiment of a method for manufacturing a rotor of the present invention using the apparatus shown in FIG. 4 will be described. The manufacturing method of the present invention includes a step of cutting a continuous cast bar into a predetermined length of a forged product , a step of applying a lubricant to the forging material, a step of preheating the forging material to a predetermined temperature, a mold preheating step, applying a lubricant to the mold, the step of introducing forging material, a step of forging the forging material, the step of discharging the forged product by the knockout pins, forged product vanes housing It is a manufacturing process including a step of cutting the groove length to be equal to or less than the axial length of the groove and penetrating the vane storage groove, and a heat treatment step of continuously solutionizing and taking out the aging treatment of the forged molded product taken out.

  Next, each step will be described step by step.

<Step of cutting a continuous cast bar into a predetermined length of a forged product ><Step of applying a lubricant to a forging material>
A columnar aluminum alloy, which is a forging material, is cut into a predetermined length in advance to form a forging material (blank) 19, and the forging material 19 is bonded to the surface or is immersed in a graphite-based water-soluble lubricant and a lubricant is applied. Apply processing.

<Step of preheating the forging material to a predetermined temperature>
In this step, the blank 19 is preheated to a predetermined forging temperature, for example, 400 to 450 ° C. The volume of the blank (forged material) 19 is not the volume of the required rotor material, but the volume of the forged product that is in contact with the pressure punch with a surplus metal portion. In addition, it is preferable that the inner diameter of the bush 16c is the same as or slightly larger than the inner diameter of the lower die 16a, because a forged molded product is smoothly knocked out after forging .

<Step of preheating the mold>
The mold 14 is preferably preliminarily heated by a heater in both the upper mold 15 and the lower mold 16 and heated and held in a range of 150 to 300 ° C.

<Process of applying lubricant to mold>
Next, a lubricant is applied to the mold 14. The lubricant may be applied only by the lower mold 16. Examples of the lubricant include a water-based graphite lubricant and an oil-based graphite lubricant. The coating amount is preferably 2 to 10 g (concentration is 0.5 to 25% by mass).

<Process to insert forging material>
As shown in FIG. 4A, in this step, a blank (forging material) 19 is introduced into the bush 16c of the mold 14.

<Forging process of forging material>
After the blank 19 is inserted into the bush 16c, when the upper die 15a made of a pressure punch is lowered, the blank 19 is pushed into the lower die 16a while receiving the back pressure from the lower punch, and FIG. As shown in FIG. 2, compression forging is started.
In addition, the position of the upper surface of the lower punch at the start of forging is 1 mm or more higher than the vane storage groove forming part of the lower die 16a in order to suppress the groove width of the vane storage groove 12 near the end surface of the forged molded product. It is preferable to start forging from a standby state. That is, the distance Z shown in FIG. 7 is preferably 1 mm or more.

  As described above, in the case of the back pressure forging method of the present invention, compression forging is performed while applying a back pressure to the front end surface of the forging material (blank) 19 during forging.

As shown in FIG. 3, the rotor forging die 14 has a die blade portion (vane housing groove forming portion) 18 protruding from the inner peripheral wall surface of the forming hole 17 in an inclined state with respect to the radial direction. For this reason, the plastic flow state of the forging material 19 becomes unbalanced on both sides of the die blade portion 18, and a nonuniform pressure is applied to the die blade portion 18. Furthermore, when using the back pressure forging method, compression forging is performed while applying a back pressure to the tip surface where the material flows during forging, so that the adhesion between the die wall surface and the forging material is improved, so that the die blade portion 18 Pressure increases. As a result, a high pressure is applied as it is to both sides of the die blade 18 in a non-uniform state, and the die blade 18 undergoes “sag deformation” and “twist deformation” due to the influence of the non-uniform high pressure. It will be. As a result, the positional dimensional accuracy of the vane storage groove 12 of the forged molded product is deteriorated.
However, in the present invention, the back pressure plate 16e is freed by removing the back pressure when a predetermined filling rate is reached, so that the high pressure applied to the die blade 18 is released, and as a result, the vane storage groove 12 is released. The deterioration of the positional dimensional accuracy can be suppressed.

When the scroll was forged by applying the conventional back pressure method, the above phenomenon did not occur. Because the scroll has a thin shape on the molded product side, it is difficult to cause non-uniform pressure balance due to the flow of the forging material, and as a result, non-uniform high pressure does not occur on the die side. It is estimated that no deformation occurs in the die.
On the other hand, the rotor has a thin shape on the die side (the shape of the die blade), while the pressure balance is uneven on both sides due to the flow of the forging material. The side will be affected by uneven high pressure. And since the die blade | wing part 18 falls in the direction perpendicular | vertical to an axial direction and is a shape which is easy to receive a deformation | transformation and a twist deformation | transformation, it is estimated that the above malfunctions have newly generate | occur | produced at the time of back pressure forge molding. The

  Therefore, in the present invention, in order to suppress the occurrence of this phenomenon and prevent the deterioration of the positional dimensional accuracy of the vane storage groove 12, the back pressure is removed when a predetermined filling rate is reached.

  Here, the predetermined filling rate can be calculated in advance by the length of the punch stroke at the time of molding. In the case of a rotor, it is necessary to remove the back pressure while the filling rate of the forging material 19 into the lower die 16a is 10% to 55%.

  In the forging process of the aluminum alloy rotor material having the vane storage groove 12, the back pressure is applied while the filling rate of the forging material 19 into the die is 10% to 55% (more preferably 10% to 30%). It is preferable to remove. This is because the high pressure applied to the die blade portion 18 that causes the die blade portion 18 to fall or twist is more reliably released, and deterioration of the positional dimensional accuracy of the vane storage groove 12 can be suppressed.

  In the present invention, the forging machine 20 provided with the back pressure device shown in FIG. 8 is used as means for removing the back pressure at a filling rate of the forging material 19 within a predetermined range during back pressure forging. A die set including an upper die 15 and a lower die 16 shown in FIG. 2 is attached to the forging machine 20, and the die set includes an upper die set plate 21, a lower die set plate 22, and a guide post 23. The lower die set plate 22 includes a hydraulic cylinder 26 for transmitting back pressure to the lower mold 16. In addition, a press operation monitoring device 28, an oil pressure generating device 27, and a hydraulic pipe 29 are provided for monitoring the press operation and transmitting an electrical signal to the oil pressure generating device 27 in order to control the back pressure. It is preferable to provide a control device that inputs, stores, or inputs operating conditions for removing back pressure, calculates timing for removing from each input condition, and stores the timing. Furthermore, it is preferable to store the conditions in a database for each product type.

  In addition to the hydraulic cushion, the back pressure generator may be provided with a device that controls (removes) the back pressure at a predetermined filling rate. For example, a gas cushion may be used. Moreover, you may combine them.

  In the example of the forging machine 20 used in the present invention, the slide angle of the upper die (pressure punch) for removing the back pressure is input to the press operation monitoring device 28 shown in FIG. An electric signal for removing the hydraulic pressure is generated in 27 to control the back pressure. In the present invention, the punch stroke is calculated based on the slide angle of the punch from which the back pressure is removed. As shown in FIG. 9, the length from the start of molding to the bottom dead center of the punch is L, and the back pressure is removed from the start of molding. The length of the punch stroke at the timing slide angle X is ΔL, and the filling rate is defined as [ΔL ÷ L × 100]%.

  In addition to the method of determining the timing to control the back pressure according to the slide angle of the punch stroke, the method of replacing the filling rate by monitoring the moving distance of the upper die (pressure punch) and calculating according to the following formula is used May be. When the length from the start of molding to the bottom dead center of the punch is M, and the length of the punch stroke moved from the start of molding is ΔM, the filling rate is defined as [ΔM ÷ M × 100]%.

  As a method of removing the back pressure, a method of removing instantaneously (for example, more preferably within 0.2 seconds, even more preferably within 0.1 seconds) at a predetermined filling rate is preferable. Rather than the method of removing the back pressure gradually as shown in Example (2) of FIG. 10 or the method of removing it stepwise as shown in Example (3), it is instantaneous at a predetermined filling rate as in Example (1). If this method is used, the back pressure plate can be freed to release the high pressure applied to the die blade portion 18, and the deformation and twisting deformation in the direction perpendicular to the axial direction of the die blade portion 18 can be suppressed. preferable.

Back pressure in the range of ^{2kg / cm 2 ~7kg / cm 2} ( more preferably 2.7kg / cm ² ~6.3kg / cm ² range, more preferably in the range of ^{3kg / cm 2 ~6kg / cm 2} ) Is preferred. Be in the range of ^{2kg / cm 2 ~7kg / cm 2} , while the vanes housed spread suppressing effect of the groove width of the groove 12 is sufficiently obtained, the mold 14 and the forging material 19 near the end surface of the forged product It is preferable because galling can be suppressed.

<Process for discharging forged molded product with knockout pin>
FIG. 4C shows a state where the back pressure is removed and the upper die 15a is lowered to the lowest end of the stroke as it is. Thereafter, as shown in FIG. 4D, the forged molded product is pushed up by the knockout pin 16g, and the forged molded product is discharged from the lower die 16a and the bush 16c.

<Process of cutting a forged molded product to a length equal to or less than the axial length of the vane storage groove and penetrating the vane storage groove>
The shape of the forged product at this time has a surplus portion 25 that does not have a vane storage groove on one side as shown in FIG. 11 (b) when an upper mold having a shape portion with a recess is used. However, the surplus portion 25 can be removed later by machining or the like to obtain the rotor material shown in FIG.

<Continuous solution of the forged product taken out><Heat treatment process for aging treatment>
Thereafter, in order to improve the mechanical strength of the forged material 19, solution treatment and artificial aging treatment are performed. The solution treatment is preferably held at 460 ° C. to 530 ° C. for 1 to 6 hours, and after water quenching (water temperature 10 ° C. to 70 ° C.), the artificial aging treatment is preferably held at 150 to 250 ° C. for 1 to 10 hours.

The aluminum alloy rotor material described above is improved in the accuracy of the groove width dimension and the groove position dimension of the vane housing groove 12. As a result, it is possible to obtain a rotor material without performing a cutting process on the lower end surface of the forged molded product that eliminates a portion with poor dimensional accuracy as a post process.
For example, the spread of the groove width in the vicinity of forged product end face of the groove width of the vane accommodating grooves 12 in 50μm or less, the height difference is 0.075mm or less at the central position of the vane accommodating grooves cylindrical portion, and below the forged product An aluminum alloy rotor material having no cutting surface on the end face can be obtained.
That is, the expansion of the groove width from the preferred position toward the central direction can be suppressed to a preferred value or less. For example, preferable positions can be 4 mm (C) from the outer periphery P and 5.5 mm (D) from the outer periphery P. A preferable value of the expansion of the groove width is 15 μm or less, more preferably zero.

  An aluminum alloy rotor can be obtained by subjecting the above-described aluminum alloy rotor material to machining for dimensioning and, if necessary, subjecting the surface to shot blasting. This is an aluminum alloy rotor in which the accuracy of the groove width dimension and groove position dimension of the vane storage groove 12 is improved, the cutting process in the subsequent process is omitted, and the number of processing steps is reduced.

Next, the forging material 19 used in the manufacturing method according to the present invention will be described. A metal material can be used as the forging material 19. Among metal materials, an aluminum alloy that is excellent in strength and corrosion resistance and can be reduced in weight is preferable. As for the composition, it is preferable that Si is 14.0-16.0 mass%, Cu is 4.0-5.0 mass%, and Mg is 0.45-0.65 mass%. Furthermore, Fe containing 0.5% by mass or less, Mn 0.1% by mass or less, Zn 0.1% by mass or less, Ti 0.2% by mass or less, and the remainder being aluminum and inevitable impurities Alloys are preferred.
Any of an aluminum alloy continuous cast bar, an aluminum alloy extruded material, a powdered aluminum alloy extruded material, or a rolled material thereof can be used as a forging material. In particular, a continuously cast round bar is inexpensive and preferable.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  The rotor material shown in FIG. 1 was manufactured using the forging device shown in FIG. 4 and the forging die shown in FIG. The lower die 16a has an inner wall surface with a molding hole 17 having a diameter of 68.26 mm, a vane housing groove forming portion thickness of 2.97 mm, a tip cylindrical portion diameter of 6.03 mm, and an axial length of 47 mm. A vane containing groove forming portion (die blade portion) 18 having five pieces at intervals of 72 ° was used.

The upper mold 15a has a recessed portion 24 which is a recess opposite to the upper mold operating direction at a position corresponding to the vane housing groove forming section as seen from above the upper mold operating direction axis as shown in FIG. I used something. In addition, the width Y of the protrusion of the forged molded product formed corresponding to the recessed shape portion 24 of the upper die 15a was 10 mm, and the height W was 10 mm. (See Figure 11)

  The diameter of the center pin 16f having a cylindrical protruding portion for forming the center hole 13 was 12 mm.

  The forging material 19 is an aluminum alloy manufactured by continuous casting. The composition of the forging material 19 is 14.0 to 16.0% by mass of Si, 4.0 to 5.0% by mass of Cu, and 0.45 to Mg. 0.65% by mass, Fe is 0.5% by mass or less, Mn is 0.1% by mass or less, Zn is 0.1% by mass or less, Ti is 0.2% by mass or less, and the remainder is inevitable with Al. An aluminum alloy which is an impurity was used. A continuous casting rod having a diameter of 67.5 mm was cut to a length of 48.75 mm to obtain a forging material 19. The forging material 19 was heated to 420 ° C. after applying an aqueous graphite lubricant. The mold 14 was heated and held at about 250 ° C. for both the upper mold and the lower mold, and 10 g of an aqueous graphite lubricant and 2.5 g of an oily graphite lubricant were applied to the lower mold.

The back pressure was 5.1 kg / mm ² and the back pressure was removed when the filling rate of the forging material 19 into the lower die was 0 to 100%. The forging load at this time was 75 tons. The forged molded product was molded until the length in the longitudinal direction of the vane storage groove 12 reached 46 mm, and the excess portion 25 not including the vane storage groove 12 was removed by machining to make the total length 44 mm.

As shown in FIG. 12, the vane storage groove 12 and the vane storage groove 12 in the plane from which the surplus portion 25 is removed from the end face of the forged product , a position 4.0 mm from the outer peripheral cylindrical portion P indicated by C, [B-A] μm was measured as the width of the groove at a position 5.5 mm from the outer peripheral cylindrical portion P indicated by D and D in the center direction. The number of samples was 30, and the average value was calculated. (Evaluation of groove width dimension)

  In order to measure the deformation and twisting deformation in the direction perpendicular to the axial direction of the die blade portion 18, the difference between the upper and lower end surfaces of the center position U of the cylindrical portion of the vane storage groove shown in FIG. The average value was calculated for each.

  Table 1 shows the upper and lower sides of the groove width of the vane storage groove 12 and the center position U of the cylindrical portion of the vane storage groove when the back pressure is removed when the filling rate of the forging material 19 into the lower die is 0% to 100%. The measurement result of the average value of the difference at the end face is shown. (Evaluation of groove position dimensions)

The evaluation symbols in Table 1 will be described. The measurement results were evaluated in the following three stages.
X: The expansion of the groove width exceeds 50 μm, or the difference in the center position of the cylindrical portion exceeds 0.075 mm.
A: The width of the groove is 50 μm or less, and the difference in the center position of the cylindrical portion is 0.050 mm or more and 0.075 mm or less.
(Double-circle): The expansion of a groove width is 50 micrometers or less, and the difference of a cylindrical part center position is less than 0.050.

  Comparative Example 1 is a result of forging without back pressure. From the measurement result of the groove width, the groove width of the vane storage groove 12 is increased in the vicinity of the product end surface.

  When the filling rate is increased, when the filling rate of Comparative Example 2 is 0%, the groove width is the same as that of Comparative Example 1, and the groove width is widened near the end face of the product.

  In the case where the filling rate shown in Comparative Example 3 is 5%, the width of the groove is improved, but the width of the groove exceeds 50 μm, but the filling rate of Examples 1 to 5 is 10% to 55%. In this case, the expansion of the groove width could be suppressed to 50 μm or less.

  In Comparative Examples 4 to 6 in which the filling rate is 60% to 100%, the expansion of the groove width can be suppressed, but the average value of the differences at the upper and lower end surfaces of the center position U of the vane storage groove cylindrical portion is 0.075 mm. Exceeding Comparative Examples 1 to 3 and Examples 1 to 5, Table 1 shows the significance of the filling rate timing for removing the back pressure load.

Therefore, by removing the back pressure when the filling rate is between 10% and 55%, the groove width of the vane housing groove is prevented from spreading near the end surface of the forged molded product , and the direction perpendicular to the axial direction of the die blade portion 18 It is possible to prevent deterioration of the dimensional accuracy of the vane storage groove 12 due to deformation by twisting or twisting. It is more preferable to remove the back pressure when the filling rate is between 10% and 30% from the viewpoint of improving the dimensional accuracy of the vane storage groove 12.

  From the data of the groove width spread shown in Table 1, the spread is largest at the outer peripheral portion shown in FIG. 12, and becomes smaller as C portion and D portion. In the present invention, the spread width at D portion can be made zero. . The range in which the groove width is expanded by 15 μm or more can be suppressed within 4 mm from the outer periphery P toward the center. Further, the range in which the groove is widened can be within 5.5 mm from the outer periphery P toward the center.

FIG. 1 is an external perspective view of a rotor material showing an example of an aluminum alloy forged molded product according to the present invention. FIG. 2 is an exploded perspective view showing a mold used to mold the rotor material. FIG. 3 is a plan view showing a lower mold for molding the rotor material. FIG. 4 is an explanatory view showing a back pressure forging method according to the present invention. FIG. 5 is an external perspective view of the upper mold according to the present invention. FIG. 6 is a perspective view of a rotor material forged with the same mold. FIG. 7 is an explanatory view showing the position of the back pressure plate at the start of molding. FIG. 8 is an explanatory view showing a forging machine and a back pressure control device according to the present invention. FIG. 9 is a diagram showing the relationship between the punch stroke and the slide angle. FIG. 10 is a diagram showing the relationship between the back pressure and the filling rate. FIG. 11A is a plan view of a rotor material according to the present invention, and FIG. 11B is a cross-sectional view taken along the line AA-O-BB. FIG. 12A is a side view in which the vane storage groove and the surplus portion of the same material are removed, and FIG. 12B is a plan view showing the measurement position of the vane storage groove. FIG. 13 is an explanatory view showing the center position of the cylindrical portion of the vane storage groove. FIG. 14 is an explanatory view showing an example of a conventional forging method.

Explanation of symbols

10 Rotor 11 Outer circumference 12 Vane storage groove 13 Center hole 14 Mold 15 Upper mold 16 Lower mold 16a Lower mold 16b Hole 16c Bush 16d Die B
16e Back pressure plate 16f Center pin 16g Knockout pin 16h Through hole 16i Dice C
17 Molding hole 18 Die blade part 19 Blank (forging material)
20 Forging machine 21 Upper die set plate 22 Lower die set plate 23 Guide post 24 Recessed portion 25 Remaining portion 26 Hydraulic cylinder 27 Hydraulic generator 28 Press operation monitoring device 29 Hydraulic piping

Claims (9)

A forged aluminum alloy rotor material having a composition of 14 to 16% by mass of Si, 4 to 5% by mass of Cu, 0.45 to 0.65% by mass of Mg, and 0.5% by mass of Fe % Or less, Mn is 0.1 mass% or less, Zn is 0.1 mass% or less, Ti is 0.2 mass% or less, the remainder is Al and inevitable impurities, and the dimensional accuracy of the forged molded product is poor However, the width of the vane storage groove in the vicinity of the end surface is not more than 50 μm without cutting the lower end surface so as to eliminate the difference, and the difference in the center position between the upper end surface and the lower end surface of the cylindrical portion of the vane storage groove Is a method for producing an aluminum alloy forged molded product for producing a forged aluminum alloy rotor material having a vane storage groove parallel to the main molding direction, characterized by having a dimensional accuracy of 0.075 mm or less. There,
Using the upper mold and the lower mold having a thin plate-like portion protruding into the molding hole, forging a forged molded product having a vane storage groove parallel to the main molding direction,
By starting molding in a state in which the back pressure plate imparting back pressure to the front end surface in the main molding direction of the forging material is waiting at a position higher by 1 mm or more than the vane storage groove forming portion provided in the lower mold, By suppressing the spread of the groove width of the vane storage groove in the vicinity of the product end surface and instantaneously removing the back pressure while the filling rate of the forging material into the forming hole is 10% to 55%, Free the pressure plate to release the high pressure applied to the die blades, and suppress the deformation of the vane storage grooves by reducing the deformation and torsional deformation in the direction perpendicular to the axial direction of the die blades. A method for producing a forged molded product made of an aluminum alloy. The upper mold includes an upper mold made of a pressure punch,
The filling rate is [ΔL ÷ L × where L is the length to the bottom dead center of the upper mold at the start of molding and ΔL is the length of the punch stroke at a predetermined slide angle of the upper mold. 100]%, The method for producing an aluminum alloy forged molded product according to claim 1 . The upper mold includes an upper mold made of a pressure punch,
The filling rate is [ΔM ÷ M × 100] where M is the length to the bottom dead center of the upper mold at the start of molding and ΔM is the length of the punch stroke when moved from the start of molding. The method for producing an aluminum alloy forged molded product according to claim 1 , wherein the method is represented by% . The method for producing an aluminum alloy forged molded product according to any one of claims 1 to 3 , wherein the back pressure is instantaneously removed while the filling rate is 10% to 30% . Back pressure is 2 kg / cm ² or more, a manufacturing method of the aluminum alloy forged product according to any one of claims 1 to 4, characterized in that a 7 kg / cm ² or less. The method for producing an aluminum alloy forged molded product according to any one of claims 1 to 5, wherein the back pressure is due to a hydraulic cushion and / or a gas cushion . The aluminum alloy according to any one of claims 1 to 6, wherein any one of an aluminum alloy continuous cast bar, an aluminum alloy extruded material, a powdered aluminum alloy extruded material, or a rolled material thereof is used as a forging material. Manufacturing method of forged molded products. The composition of the aluminum alloy is characterized by using a forging material in which Si is 14 to 16% by mass, Cu is 4 to 5% by mass, Mg is 0.45 to 0.65% by mass, and the remainder is Al and inevitable impurities. The method for producing an aluminum alloy forged molded product according to any one of claims 1 to 7. The composition of the aluminum alloy for forging is added with Fe 0.5 mass% or less, Mn 0.1 mass% or less, Zn 0.1 mass% or less, and Ti 0.2 mass% or less. A method for producing an aluminum alloy forged molded product according to claim 8.

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