JP2000117380A - Manufacture of aluminum alloy rotor stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong the service life of a die, and to improve the dimensional accuracy of a vane storage groove by casting the vane storage groove in a non-piercing manner leaving part without any groove formed thereon, and mechanically removing the part thereafter. SOLUTION: An aluminum alloy material is heated and charged in a case 9 as a blank 13. The volume of the blank 13 is larger than that of a rotor stock. The inside diameter of the case 9 is same as or slightly larger than the inside diameter of a die 5. A press punch 12 is lowered. The blank 13 is filled in the die 5, leaving an excessive material part which is longer than a part of the rotor stock. A knock-out pin 11 is raised from the lower part, and a forged stuff is knocked out. The shape of the forged stuff is left behind in the excessive material part without vane groove on one side. The excessive material part is mechanically removed from the forged stuff. The thickness of the part without any vane storage groove is >=0.5 time to <=4 times of the width of the vane storage groove.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a raw material such as a rotor of a rotary compressor for air conditioning mounted on an automobile and a rotor of a rotary vacuum pump for brake control.

[0002]

2. Description of the Related Art For the purpose of weight reduction, the rotor of a rotary compressor for air conditioning and the rotor of a rotary vacuum pump for brake control mounted on an automobile are mainly made of aluminum alloy. Normally, the material of the rotor has a shape in which a plurality of grooves (vane storage grooves 2) for accommodating vanes are cut inward from the outer periphery of the cylinder as shown in FIG. Eventually, this material is machined in the center of the material to make a hole for shaft insertion,
Machined for dimensioning and used for rotor manufacturing.

[0003] As a method of manufacturing the rotor material, there is known a method in which a grooved bar is produced by a hot extrusion method and is cut into a ring. This method has an advantage that a large number of rotor materials can be efficiently manufactured. However, since the position of the groove 2 of the rotor is deviated from the center of the shaft (see d in FIG. 1A), the plastic flow of the material is unbalanced on both sides of the groove. For this reason, there is a problem that the torsion and bending become large, especially in the case of a long extrusion rod, and as a result, the groove dimension accuracy of the product is poor. Further, since there is no lubrication between the die and the material, there is a problem that the surface properties of the product are liable to be deteriorated and cracks are generated in the extruded material.

To solve this problem, a hot forging method is known. For example, a hot forging method as disclosed in Japanese Patent Application Laid-Open No. Hei 3-165948 has been proposed. In this case, the above problem is considerably solved because the product is forged one by one, the molding length is short and the die is lubricated each time. However, in this forging method, the load applied to the die portion (see FIG. 2; hereinafter, referred to as the die blade portion 7) that forms the vane housing groove is opposite in the direction of molding and the time of discharging the product. There is a problem that the die blades 7 vibrate in the direction, the die blades 7 are easily damaged, and the life of the die is short.

Further, as shown in FIG. 2 (d), the vibration of the die blade portion 7 is not limited to the axial direction due to the position of the die blade portion deviating from the axial center. A twisting deformation has occurred, including deformation in a direction perpendicular to the axis. In addition, it is considered that the sinking and twisting of the die blade portion 7 are the main causes of deteriorating the dimensional accuracy of the vane storage groove of the forged product.

[0006] In order to solve this die blade slack, for example, Japanese Patent Application Laid-Open No. 3-138043 discloses a method in which a backup portion is provided below the die blade portion to support the die blade portion. It is described that there is an effect of improving the dimensional accuracy of the vane housing groove due to backlash and the like and the die life. However, as a result of investigations by the present inventors, this method did not provide a sufficient life for mass production. This is because, in the method of supporting the lower part of the die blade, the upper part of the die blade part is not fixed at the time of forging, so it freely deforms, while the lower part is fixed and does not deform. It is considered that a large twisting occurs between the upper and lower portions, and the load on the die blade portion is not reduced.

[0007]

SUMMARY OF THE INVENTION The present invention solves the problem that the life of a die is short when a rotor material is manufactured by a hot forging method. It is intended to improve the accuracy.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. [1] When manufacturing a rotor material made of an aluminum alloy having a vane accommodating groove by a forging method, the vane accommodating is performed. A method of manufacturing a rotor material made of an aluminum alloy, comprising forging into a shape that does not penetrate the groove and leaving a part where the vane storage groove is not formed, and then removing a part where the vane storage groove is not formed by machining. [2] The method according to [1], wherein the thickness of the part where the vane storage groove is not formed is 0.5 to 4 times the width of the vane storage groove. [3] In forming a portion where the vane storage groove is not formed, a punch having a concave portion at a position corresponding to a die blade portion for forming the vane storage groove is used. A method of manufacturing the above-mentioned [1] or [2] which, and [4] [1] width is less than 6 times 1 times the width of the die blade portion of the concave portion of the punch-
The production method according to [3].

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS To explain the present invention in more detail, FIG. 4 shows a process of manufacturing a rotor material by forging. The aluminum alloy material used as the material is
As shown in FIG. 4A, the sheet is cut into a predetermined length, heated, and put into a case 9 as a blank 13. At this time, the volume of the blank 13 is set to be an extra volume so as to have extra thickness in the axial direction from the required volume of the rotor material as described later. The inner diameter of the case 9 needs to be equal to or slightly larger than the inner diameter of the die 5 in order to smoothly knock out the forged material. Next, FIG. 4B shows a state in which the pressing punch 12 descends from above and completes a predetermined stroke movement. In this state, the blank 13 is filled in the die 5 and, as described above, leaves an extra portion than the length required for the rotor material. Next, as shown in FIG. 4C, the knockout pin 11 rises from below to knock out the forged product. At this time, the shape of the forged product has a surplus portion L 'having no vane groove on one side as shown in FIG. The excess portion reduces the load applied to the die blades from the pressure punch and suppresses the deformation of the die blades. This forged product has a surplus portion L ′ removed by post-machining or the like to have the shape shown in FIG.

In FIG. 4, the excess portion is formed by a blank in the case 9, but as shown in FIG. 5, the blade portion 7 in the die is made lower than the die height, and It is also possible to leave a surplus part. In addition, the surplus portion can be limited to only the vicinity corresponding to the vane housing groove as shown in FIG. In this case, as shown at 14 in FIG. 7, a recess may be provided around the portion corresponding to the die blade portion of the punch, and the excess may be left near the vane storage groove of the forged product.

In the present invention, the thickness of the above-mentioned surplus portion is proportional to the size of the metal flow region formed above the die blade. The size of the metal flow region varies depending on the shape of the upper surface of the die blade, such as how to take the R of the edge of the die blade and the width (area) of the flat portion. 2 t. The same applies to the width of the vane storage groove of the forged product). As a result of the study by the present inventors, the main metal flow region was located in the surplus portion at a distance from the upper surface of the die blade of the forged product to approximately four times the width of the die blade. However, as the thickness of the surplus portion increases, the input material amount increases. Therefore, it is preferable that the thickness is as small as possible from the viewpoint of material yield. On the other hand, if the thickness of the surplus portion is less than 0.5 times the width of the die blade portion, the effect of reducing the load applied to the die blade portion, which is the target of the present application, cannot be obtained. Therefore, the thickness of the excess portion is preferably 0.5 times or more and 4 times or less the width of the die blade portion. More preferably, in order to obtain a sufficient effect on the life of the die, it is desirable that the thickness of the surplus portion be at least one time the width of the die blade, and most preferably at least 1.5 times the thickness. is there. Here, the width of the die blade means the interval (t in FIG. 2) between the planes of the blade parallel portions on both sides. Further, the width of the die blade portion here does not substantially change even as the width of the vane housing groove formed by the die blade portion (t in FIG. 1).

Further, since it is sufficient that the surplus portion only reduces the load caused by the punch only in the vicinity of the vane storage groove, the necessity of the extra space between the adjacent vane storage grooves is small. Therefore, a concave portion may be provided in the punch to leave a convex excess only in the vicinity of the vane housing groove (see FIG. 6). In this case, the punch between the die blade portion and the blade portion becomes relatively convex. Therefore, the space between the die blades is filled with metal as soon as possible, and there is also an effect of suppressing deformation of the die blades from the side. Regarding the shape of the concave portion of the punch, the concave portion may be provided only at a portion corresponding to the length in the center direction of the blade as shown in FIG. 7, or a plurality of concave portions corresponding to the number of the die blade portions as shown in FIG. It is also possible to use a shape in which the grooves are connected at the center (see FIG. 6 of a forged product). Regarding the width w of the concave portion of the punch, if the width is too narrow, the metal does not easily protrude into the concave portion, and a sufficient effect cannot be obtained. On the other hand, if the width is too large, the effect of suppressing the die blades from the side described above is reduced, and therefore, it is more effective to suppress the die blades to a certain width. In view of the above, the width w of the concave portion of the punch is 1 to 6 times the width of the die blade portion, and preferably 2 to 4 times.

[0013]

According to the present invention, the load applied to the die blades by the pressure punch at the time of forging is provided by adding an extra metal portion to a portion of the forged product which comes into contact with the pressure punch, and freeing the metal flow near the die blade portion. Since the direct load from the pressure punch is absorbed by the metal portion and the load on the die blade portion is reduced, the life of the die can be extended and the dimensional accuracy of the vane storage groove can be improved.

[0014]

The present invention will be described in more detail with reference to the following examples. Example 1 As a die, the diameter of the inner circumference 6 in FIG.
Forging was performed using 4.9 mm, a blade length 1 of 18.5 mm, a blade portion width t of 4.1 mm, a blade height h of 37 mm, and a punch having no concave portion. A3 as material
Using an aluminum alloy of 90 composition as a blank, φ
The thickness of the surplus portion of the forged product was adjusted from 2 mm to 15 mm by changing the blank thickness of a material having a size of 61.3 mm. Forging conditions are as follows: blank temperature 300 to 460 ° C, die and pressure punch temperature 100 to 350 ° C, load 20 to 1
00t. The dimensional accuracy was investigated by measuring the parallelism of the vane storage groove of this forged product with reference to the cylindrical outer periphery, and the die life was examined from the number of shots until the die was broken. The degree of parallelism is the degree of parallelism with respect to the forged product outer diameter cylinder.

Comparative Example 1 Using the same dies and punches as in Example 1, forging was performed under the same forging conditions. However, as a blank material of aluminum alloy of A390 composition, φ61.3 m
m was changed so that the thickness of the excess portion of the forged product was 1.2 mm. Table 1 summarizes Example 1 and Comparative Example 1. As a result, it can be understood that the die life is remarkably improved and the dimensional accuracy is also improved by the extra thickness forging.

Example 2 The diameter of the inner periphery 6 of FIG. 2 is 62.5 mm, the number of blades 7 is five, and the distance d between the center of the blade and the center of the shaft (the amount of deviation)
4.8 mm, blade length 1 is 18 mm, blade width t is 3.
A punch having a diameter of 2 mm and a blade height h of 51 mm was used, and a punch having a shape in which the concave portions in FIG. 8 were connected at the center and having an average concave width w of 10 mm was used for forging. As a blank, an aluminum alloy having a composition of A390 and a size of φ61.3 mm was used as a blank. The forging conditions were the same as in Example 1.

Embodiment 3 The same dies and the same material as those in Embodiment 2 are used, and the punch has a shape in which the recesses shown in FIG. 7 are independent of the die blades. Forging was carried out using a 9 mm one. The forging conditions were the same as in Example 1.

Example 4 The same dies and the same material as in Example 2 were used. The punch had the shape shown in FIG. 7 and the average recess width w was 4.8 mm.
Forging was performed using The forging conditions were the same as in Example 1.

Example 5 The same dies and the same material as in Example 2 were used. The punch had the shape shown in FIG. 8 and the average recess width w was 14.3 m.
m forging was performed. The forging conditions are the same as in Example 1.
The same as above.

Comparative Example 2 The same die and the same material as in Example 2 were used. The punch had the shape shown in FIG. 7 and the average recess width w was 2.9 mm.
Forging was performed using The forging conditions were the same as in Example 1.

Table 2 shows the measurement results of the parallelism of the vane storage grooves of the forged products of Examples 2 to 5 and Comparative Example 2. From this result, the effect of providing the concave portion in the punch portion of the present invention is seen.

[0022]

[Table 1]

[0023]

[Table 2]

[0024]

According to the present invention, when a rotor material is manufactured by hot forging, the load applied to the die blades during forging can be reduced, and as a result, the life of the die can be extended. Further, the dimensional accuracy of the vane storage groove is improved.

[0025]

[Brief description of the drawings]

FIG. 1 is a view showing a rotor material shape before the present invention;
(A) is a top view, (b) is a figure which shows the BOB cross section of (a).

FIGS. 2A and 2B are diagrams showing an example of a die shape used for forging of the present invention, wherein FIG. 2A is a plan view of the die, and FIG.
FIG. 2C is a cross-sectional view taken along line OX, and FIG.

FIG. 3 is a view showing a rotor material shape according to the present invention;
(A) is a top view, (b) is a figure which shows the B-0-B cross section of (a).

FIGS. 4A and 4B are diagrams showing a forging process according to the present invention, wherein FIG. 4A is an explanatory view of blank input and before forging, FIG. 4B is immediately after forging, and FIG.

5A and 5B are diagrams showing another example of the forging process according to the present invention, in which FIG. 5A shows blank injection and before forging, FIG.
(C) is an explanatory view of forging discharge.

FIG. 6 is a view showing another example of a rotor material shape according to the present invention.

FIGS. 7A and 7B are diagrams showing an example of the shape of a pressure punch used for forging of the present invention, wherein FIG. 7A is a plan view, and FIG.
It is a figure which shows the OX cross section.

8A and 8B are diagrams showing another example of the shape of the pressure punch used for forging of the present invention, wherein FIG. 8A is a plan view, and FIG. 8B is a diagram showing a cross section taken along line X-OX of FIG. is there.

[0026]

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rotor material 2 vane storage groove 5 dice 7 die blade 9 case (container) 10 anvil (die plate) 11 knockout pin 12 pressure punch 13 blank 14 depression of pressure punch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hidemi Yamada 7840, Chikata, Kitakata, Fukushima Pref. Reference) 3H040 AA08 AA09 BB07 CC14 CC16 DD07 DD08 DD35 DD36 4E087 AA09 BA04 CA13 CA15 CB01 DA02 DB04 EA11 EC02 EC38 EC39 EE02 HA00

Claims (4)

[Claims] When an aluminum alloy rotor material having a vane storage groove is manufactured by a forging method, the rotor material is forged into a shape that does not penetrate the vane storage groove and leaves a portion where the vane storage groove is not formed. A method of manufacturing a rotor material made of an aluminum alloy, wherein a portion where a groove is not formed is removed by machining. 2. The manufacturing method according to claim 1, wherein the thickness of the part where the vane storage groove is not formed is 0.5 times or more and 4 times or less the width of the vane storage groove. 3. A punch having a concave portion provided at a position corresponding to a die blade portion for forming a vane storage groove when forming a portion where the vane storage groove is not formed. Or the production method according to 2. 4. The method according to claim 1, wherein the width of the concave portion of the punch is not less than 1 and not more than 6 times the width of the die blade portion.