JPH03138043A - Manufacture of aluminum alloy rotor stock - Google Patents

Abstract

PURPOSE:To obtain the stock for a high accuracy rotor by providing a backup part having grooves to insert extended fin parts provided fin parts to determine the shape of a vane housing groove and disturbing the inclination of the fin parts by the abutment between the extended fin part and the groove when the blank is worked. CONSTITUTION:The shape of the outer peripheral surface of the stock for the rotor 1 is determined, a blank 15 is forced by a pressing punch 16 into a bottomed die 5b having an inner peripheral surface served as the root part, too, of a fin part and the fin part determining the shape of the vane housing groove 52 and a die hole part determined by the bottom, the inner peripheral surface and the fin part is filled with the blank. Inclination, twisting, etc., of the fin part are prevented by a backup plate 4 on the bottom part of the die. The blank 15 is taken out as actuating the knock-out punch 14 in the opposition to the direction of the pressing punch. The blank is taken out easily when the sectional area of a container 12 is increased to the area of the die hole. In this way, the stock of a high accuracy rotor can be manufactured by a compact equipment of low capacity at a high speed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for manufacturing a rotor. More specifically, the present invention relates to a method for manufacturing a rotor, and more specifically, a rotor for a rotary compressor for air conditioning mounted on a car, and a Rochley type rotary compressor for controlling a brake. The present invention relates to a method of manufacturing a rotor, etc. of a vacuum pump.

[Prior art] The rotor of an air-conditioning rotary compressor mounted on a car or the rotor of a rotor-type vacuum pump for brake control has a
In the past, iron-based sintered alloys were often used, but in recent years, the use of aluminum has been considered for the purpose of weight reduction.

The rotary rotor for air conditioning installed in automobiles has the 8th rotor.
As shown in the figure, a groove 52 in which the vane is housed is cut inward. The purpose of this tip is to reduce the concentration factor of stress applied to the groove 52 and its bottom, to form a relief part for a tool during finishing machining of the groove, to facilitate machining, and to apply back pressure to the vane. A cylindrical portion 53 is often formed for the purpose of improving sealing performance. The rotor 1 also has a shaft hole 54 into which a steel shaft is press-fitted.
has.

Tensile stress acts on the cylindrical portion 53 at the bottom of the groove when the shaft is press-fitted into the shaft hole 54, and when the compressor is in operation, the vanes housed in the groove 52 repeatedly move into the groove while compressing the refrigerant. In order to slide inside, tensile stress is repeatedly applied to the cylindrical portion 53. As compressors become smaller, it becomes necessary to move the cylindrical portion 53 of the vane as close as possible to the shaft hole 54 of the rotor, and the stress applied to the cylindrical portion 53 from the steel shaft becomes even higher.

In order to withstand such load stress, it is essential that the aluminum alloy has no casting defects (forging, etc.) to destroy the cast structure in the grooves, and that it has heat treatability.

As a method for manufacturing such a rotor, a hot extrusion method that can completely destroy the cast structure has conventionally been adopted. This method has the advantage that a long extruded material can be obtained and a large number of rotors can be efficiently manufactured by cutting, but it has the following problems.

■The extruded material is easily twisted (also causes bending and warping), resulting in poor dimensional accuracy (and lower yield during finishing processing).

■The stress on the die is high and the life of the die is short. The die is particularly prone to breakage at the groove portion where the vane is housed.

■Since there is almost no lubrication effect between the die and the extruded material, galling and cracking occur in the extruded material. If there is any galling or cracking on the outer periphery, which serves as a processing reference during finishing, the machining axis of the vane housing or shaft hole will become eccentric, making it impossible to ensure the positional accuracy of the groove that houses the vane. In addition, nicks and cracks that occur in the cylindrical portion of the groove bottom act as notches when stress is applied to the cylindrical portion during use, reducing the durability of the rotor.

(2) A large pressing force of 800 to 2,500 tons is required during extrusion, making the equipment large and expensive.

■ Unlike a round bar, the rotor is a deformed material, so there are many sliding parts between the die and the extruded material, which can cause cracks in the extruded material unless it is extruded at a very low speed. For this reason, although it is an expensive facility, productivity is extremely low, and the cost of the rotor material obtained is extremely high.

Furthermore, as compressors become smaller, manufacturing the rotor becomes more difficult. That is, as the diameter of the rotor becomes smaller and the performance becomes higher, it becomes necessary to ensure the length of the vane as long as possible, so the cylindrical portion at the bottom of the groove in the vane storage portion approaches the shaft hole. In order to keep this distance above a certain level in order to ensure the strength of the rotor, the shift amount f of the groove 52 from the center of the rotor axis must also be increased (as shown in FIG. 9. This means that the groove 52 and This leads to the rotor's outer circumferential wall being thinner on one side of the groove, which further causes the aforementioned problem (2) to be easily twisted due to the imbalance of plastic flow during extrusion, which can extend the life of the mold. and further deteriorate dimensional accuracy.

The present applicant has previously proposed a method perpendicular to the axial direction in the container with respect to a cross section perpendicular to the axial direction of the die hole, as a means to improve the shortcomings of dimensional accuracy, surface scratches, processing yield, and die life due to the conventional hot extrusion method. using a mold structure having a container with a cross-sectional area ratio of 1=1 to 1:2 and a die backed up by a container and a die plate arranged coaxially with each other,
Insert the heated blank into the heated container;
The blank is pushed into the hole of a heated die having the outer contour shape of the rotor material using a pressure punch.
A manufacturing method is provided in which a blank filled in a space created by a container punch-die plate and shaped is knocked out and taken out through a container by a knockout punch in the die plate.

FIG. 10 shows an example of the entire mold structure exemplified in this patent application, and the die 5b is made of a die body shrink-fitted by Guiling, as shown in detail in FIGS. 2 and 3. The outer contour of the rotor material (see Figure 8) is a two-dimensional shape that serves as the die space, and the die 5
One end surface of b is brought into close contact with the die plate 13. A container 12 is heated and maintained at 300 to 450°C by a heater (not shown) together with the dice 5b. Reference numeral 13 denotes a die plate, which has a structure in which it completely contacts the fin portion 10 (Fig. 2) of the die 5b and the small cylindrical portion 11 (Fig. 2) at the tip thereof, respectively. A knockout punch 14 is provided in the center of the figure, and is designed to knock out the rotor material 15 upward in the figure after forging is completed. Further, a pressure punch 16 is attached to a platen (not shown) at the top. If this method is used, it is possible to significantly reduce the axial shear stress acting on the fin portion 10 (Fig. 2) of the die that corresponds to the vane housing, and extend the life of the die. For small, high-performance rotors, the shift amount f(
(Fig. 9) increases, the plastic flow becomes thicker in the V-shaped region a on one side of the fin in the die hole, and becomes smaller in the region V on the opposite side, causing an imbalance in the plastic flow. During molding, a force is applied to the fin portion in the direction of the arrow in Figure 2, causing sagging deformation in the fin portion 10 of the die, resulting in poor dimensional accuracy of the rotor material and problems with the life of the die. Do you get it.

[Problems to be Solved by the Invention] The present invention relates to a method for manufacturing a rotor that punches aluminum alloy. The object of the present invention is to provide a method for manufacturing an alloy rotor material.

[Means to solve problems]

The present invention solves the above problem by inserting a blank made of an aluminum alloy into a container for producing a raw material for an aluminum alloy rotor in which vane storage grooves are cut inward from the circumferential surface, and Pushing the blank with a pressure punch into a die with a bottom, which has an inner peripheral surface that determines the outer peripheral surface shape of the material and also serves as the base of the fin portion described below, and a fin portion that determines the shape of the vane storage groove, filling a die hole defined by the bottom, inner circumference and fins with the blank, reducing or maintaining the cross-sectional area of the blank substantially the same with respect to the cross-sectional area of the container; In the method for manufacturing an aluminum alloy rotor material, the blank is taken out of the container by operating a knockout punch whose tip surface functions as a part of the bottom of the die in a direction opposite to the pressing direction of the pressure punch. an extension fin portion extending toward the bottom of the die hole is integrally provided in the die hole, and a groove into which the extension fin portion is inserted with or without a gap between at least a part of the circumferential surface of the extension fin portion; During the blank processing, a backup section having a
This problem was solved by preventing the fin portion from collapsing by bringing the extended fin portion into contact with the groove.

Specifically, as will be explained in the examples below, in order to prevent the mold fins forming the vane housing part and the small cylinder from sagging, which poses a particular problem in terms of mold strength, The mold bone in which the gap between the die and the fin part in the spatial cross section is L is the distance from the root to the center of the small cylindrical part, and preferably has a backup plate having a dimension of 0.008 L or less in whole or in part. Use a mold structure or a mold in which a backup plate and die are integrally molded.

[Effect]

The method of the present invention needs to satisfy the following requirements (1) to (2).

■Use a pressure punch to push the blank into a die with a bottom, which has an inner circumferential surface that defines the outer circumferential shape of the rotor material, and also serves as the base of the fin section below, and a fin section that defines the shape of the vane storage groove. It must be a forging process that fills the die hole defined by the bottom, inner circumferential surface, and fin part with a blank. By using such a die forging process, the shape of the outer circumferential surface of the rotor material and the vane housing groove can be formed all at once without using an extrusion method.

(2) In order to take the blank out of the die after molding, the knockout punch is operated in the opposite direction to the pressing direction of the pressure punch, and the blank is taken out of the container. The tip of this knockout punch functions as part of the die bottom during forging.

■ increasing the cross-sectional area of the container with respect to the area perpendicular to the axis of the die hole or keeping it substantially the same; The cross-sectional area of the die hole is larger than the container (this makes it difficult to remove the blank with a knockout punch).
It must be avoided that the cross-sectional area of the die hole is larger than the cross-sectional area of the container.

With such a processing method, the structure of the rotor material in the vicinity of the groove of the vane storage portion can be made to plastically flow, thereby making it possible to strengthen the rotor material. The deformation of the fin, such as the fin caused by the above-mentioned plastic flow imbalance, is backed up by the bottom of the die, and the main part of the fin (the part involved in forming other than the extension part) is backed up by the contact between the surfaces. ) to prevent undesired collapse or twisting.

When a die is machined into a two-dimensional shape using a wire electrical discharge machine or the like, a back-up for preventing deformation of the fin part is fitted on the circumferential surface of the die or the end of the fin part (the bottom part of the die), or a gap is made. By creating a mold with a bottom and a hole through which the knockout punch passes,
You can make the backup effect wait.

In the case of the fitting type, it is necessary to form a gap on the fin circumferential surface, and the amount of the gap should be 0.008 L or less in whole or in part when measured in the direction perpendicular to the circumferential surface of the fin part. preferable. However, as shown in FIG. 1, L is the distance from the base of the fin portion 10 to its tip (if there is a cylindrical portion 11, the distance to its tip).

When the gap 74 is 0.008L or more, the amount of deformation of the fin part 10 is large, and the wall surface of the bottom of the die is originally in contact with the end of the fin, and even in a situation where this should be backed up, the end part is not backed up and becomes plastic. This is not preferable because it will cause deformation. In this case, the fins may undergo plastic deformation, and the twisting of the vane storage grooves may exceed the machining and finishing allowance for the rotor material. - If star-shaped deformation occurs, it will not return to its original position, which is extremely inconvenient in mass production, as it may result in a large number of defective products.

As a backup plate for preventing deformation of the fin portion of a die processed into a two-dimensional shape, a backup plate fitted into the bottom side of the die is used so as to become the bottom part of the die. That is, in this case, parts constituting a part of the die other than the die 5b and the die plate 13 (see FIG. 10) are used as a backup plate.

The backup plate is shown in FIG. 4, for example, and has a hole 71 in the center through which the knockout punch passes, and grooves 7 into which the fins and cylindrical parts of the die enter.
2 and the cylindrical portion 73 are cut out. The main surface 4a of the backup plate 4 constitutes a part of the bottom surface of the mold.

FIG. 1 is a horizontal sectional view of the bottom of the die, showing the die 5b'
and the relationship between the backup plate 4 and the die 5b.
' indicates that the fin portion 10 is the groove 72 of the backup plate 4,
The ring-shaped part that enters the cylindrical part 73 (FIG. 4) with a small gap 74 to facilitate insertion of the fin part, and serves as the base for protruding the fin parts 1 and 0 is also attached to the back-up plate 4 on the side surface. There is a small gap 74 between the die hole and the main surface 4 of the backup plate 4.
a and the tip of the knockout punch.

Regarding the method of setting the backup plate in the die space, in addition to the inset method, the method shown in Figure 5 (
It is also possible to fix to the die plate 13 with bolts 32 as in a). Although not shown, it is also possible to fix the backup plate 4 to the die 5b. Furthermore, it is also possible to integrate the die plate 13 and the backup plate 4 as shown in FIG. 5(b). moreover,
Figure 5(C) and its A-A! ! As shown in FIG. 5(d), which is a cross-sectional view, it may be a bottomed mold that is integrated with the die and has a hole through which a knockout punch passes. In addition, when using a die with a bottom, it is advantageous for the life of the mold to provide a corner radius as large as possible at the joint between the fin portion and the bottom surface of the die. The axially perpendicular cross-sectional area (Sl) of the die hole of the die 5b (see FIG. 6) is 1:1 to 1:2 with respect to the axially perpendicular cross-sectional area (S2) inside the container 12.
It is preferable that If this ratio is less than 1:1, the rotor material that has been forged cannot be knocked out through the container 12. On the other hand, this cross-sectional area is 1 to 2
In this case, a large pressure is required to force the rotor material into the die hole, which increases the stress applied to the die 5b, shortens the life of the die 5b, and easily causes the lubrication to run out.

Using the above mold structure, a heated blank is inserted into a heated container, and is pushed into a heated die or mold by a pressure punch, so that the blank is approximately placed within the molding space within the die or mold. The blank is filled and knocked out through the container by the knockout punch 14 and taken out.

This method provided a backup effect against the sagging deformation of the mold fins caused by imbalance in the plastic flow of the blank during forging, making it possible to obtain a rotor material with good accuracy.

Furthermore, we were able to strengthen the structure of the rotor material near the grooves of the vane storage section by causing plastic flow.

〔Example〕

The details of the present invention will be explained based on embodiments shown in the drawings.

As shown in FIG. 9, outer diameter D = 50-2 mm s
Diameter D+ of the circumference in which the plurality of cylindrical parts 53 are arranged at the bottom of the groove
= 14.33 mm, inner diameter d of cylindrical portion 53 = 4.5 mm
, width t of the (vane) groove 52 = 2.7 mm, angular interval θ in the circumferential direction of the open end of the (vane) groove 52 = 72, shift if from the rotor axis center to the (vane) groove center = 1
Rotor material 1 for a rotary compressor for air conditioning mounted on a vehicle having a diameter of 0 mm was manufactured.

The die 5b shown in FIGS. 2 and 3 has a fin portion 10 corresponding to the groove 52 and a small cylindrical portion 11 corresponding to the groove bottom from the die inner circumference 6 corresponding to the outer circumference of the rotor material 1. Five stand out. The die 5b is manufactured to have a hole size that takes into account thermal expansion with the mold material during hot forging so that the above-mentioned dimensions can be obtained as the rotor material dimensions after molding. still,
The distance L from the base of the die fin section shape to the center of the small cylindrical section (see FIG. 1) is approximately 12.5 mm.

In FIG. 7, 12 is a container, 5b is a die, and 4 is a backup plate, each of which is heated and maintained at 300° C. to 400° C. by a heater (not shown).

Reference numeral 13 denotes a die plate, which is structured to be in close contact with the fin portion 7 and small cylindrical portion 8 of the die 5b. The backup plate 4 has a shape as shown in FIG. 4, and has a thickness t.
b was set to 8 mm. Distance from die 74 (see Figure 1)
is 0.02mm (12.5mm x 0.008=O,
10 mm or less).

An example of an actual forging operation will be described below.

The inner diameter of the container 12 (see Figure 7) is 50.3 mm.
The ratio of the cross-sectional area perpendicular to the axial direction of the die hole of the die 5b to the cross-sectional area perpendicular to the axial direction of the container 9 is 1:1.1.
And so.

A knockout bunch 14 is provided on the die plate 13 and the die 5b to knock out the rotor material 1 that has been completely forged upward in the figure. As the aluminum alloy, 11% by weight (all percentages indicate weight%) Si manufactured by a hot-top continuous casting method was used.
, 5%Cu, 0.6%Mg, 0.3%Fe, 0.8
%Mn, the remainder being substantially A1, with a diameter of 5'O
A forged material with a height of 45 mm, that is, a blank was used. This blank was heated to 350 to 480°C in a continuous heating furnace, and hot forged in the process shown in FIG. 7 under conditions of a container temperature of 480°C and a die temperature of 400°C.

The maximum pressure during forging was 15 tons.

FIG. 7(a) shows a state in which the heated blank 15 is automatically inserted into the container 12 and then forging is started by the pressure punch 16. Note that, before forging, the container 12 and the die body 5b were sprayed with an appropriate amount of a lubricant containing graphite as a main component to form a thin lubricant film on their surfaces.

The surface of the blank 15 may not be lubricated, but it is more difficult to seize if the same lubricant film is provided on the die body 5b.

FIG. 7(b) shows a state in which the pressure punch 16 has completed a predetermined stroke movement and the blank 15 has been forged into the die 5b. In this state, blank 15 is dice 5
It is sealed inside b and finished to the predetermined dimensions. Furthermore, when mass-producing forging, it is necessary to take measures that take into consideration the dimensional variations of the blank 15. For example, when using a hydraulic press, set the maximum load, and when using a mechanical press, keep the stroke constant using the butting method shown in the figure to minimize the risk of die breakage. desirable.

In FIG. 7(C), after the blank 15 is made into a rotor material of a predetermined shape by the pressure punch 16, the pressure punch 16 is moved back by a predetermined stroke and separated from the container 12, and then the forged blank is removed by the knockout bunch 14. 15, that is, the rotor material is taken out from the container 12.

As explained above, at the end of forging, the die is almost completely filled with blanks, so it is possible to manufacture a rotor material with high dimensional accuracy without bending, twisting, or warping. Furthermore, compared to the hot extrusion method, the above method can apply lubricant to the die etc. after each forging to achieve a lubricating effect, so there are no scratches or cracks caused by the sliding of the blank with the container or die. The occurrence of can be suppressed.

In order to quantitatively demonstrate the effect of the backup plate, which is a feature of the present invention, the common condition is that the die fin section has a die plate as a backup part in the forging axis direction, and that dies of the same size are used. We investigated how the presence or absence of a backup plate affects the amount of sagging deformation of the die fin by actual forging.

The measurement results are shown in the table below.

From Table 1 and above, it is clear that the installation of the backup plate has the effect of reducing the sagging deformation of the die fin portion.

More than 2,000 blanks were forged using this method, and rotors were completely machined, but no machining defects due to poor material dimensions occurred.

Regarding the die dimensions, no change was observed before and after forging.

In the above example, an aluminum alloy blank made by continuous forging was used, but aluminum alloy powder containing high silicon (17%5i-4%Cu-1%Mg
It was confirmed that a rotor material can be manufactured even from a blank made by hot compression molding of -5% Fe-balance At.

In both cases, in the structure near the bottom of the vane groove of the rotor material obtained, there were parts that had undergone plastic flow due to forging, and the strength and toughness were improved.

In the embodiment of the present invention, the pressure punch is provided in the upper part and the die is arranged in the lower part, but the structure may be turned upside down or may have a horizontal structure.

[Effects of the Invention] According to the method of the present invention, a better lubrication effect can be obtained compared to the hot extrusion method, less scratches and cracks occur, and a back-up for preventing the die fin from sagging. Due to the plate effect, high-precision rotor materials can be manufactured at high speed using small, low-capacity equipment.

In addition, according to the method of the present invention, the surface condition and dimensional accuracy are superior compared to the rotor material obtained by manufacturing using the conventional hot extrusion method, so the finishing processing cost can be reduced (it can be set and the burden of post-processing can be reduced). It can be reduced.

In addition, due to the backup effect of the die fin section, which causes strength problems, when the fin section receives bending stress and shear stress in the axial direction of the rotor shaft, and further receives bending stress acting in the direction of collapse, the die fin The deformation of the die can be significantly reduced and the life of the die can be extended.

If the method of the present invention is applied to the method previously provided by the applicant, dimensional accuracy, surface scratches, processing yield, die life, etc. can be improved, and the repetitive stress applied to the groove bottom of the vane storage part and the impact during liquid compression can be improved. In order to withstand such stress, at least the structure near the vane housing part and the groove bottom is strengthened by plastic flow through forging, and a mechanism to prevent sagging deformation of the mold fin part that corresponds to the vane housing part is added. This allows the dimensional accuracy to be further improved.

Furthermore, it was possible to strengthen the structure of the rotor material near the groove of the vane housing by causing the composition to flow.

[Brief explanation of the drawing]

FIG. 1 is a horizontal sectional view of the die bottom and backup plate used in the method of the present invention, FIG. 2 is a plan view of the die without the backup plate previously provided by the applicant, and FIG. Figure 4 is a perspective view of the backup plate, Figure 5 (a)
, (b) is an explanatory diagram of how the backup plate is assembled into the die, Figures 5 (C) and (d) are a plan view and a sectional view when the die and the backup plate are integrated into a bottomed mold, Figure 6 is an explanatory diagram of the cross-sectional area of the die and container, and Figure 7 (
a) to (c) are cross-sectional views of a forging device showing the steps of the manufacturing method according to the present invention; FIG. 8 is a perspective view showing an example of a rotor of a rotary compressor for air conditioning mounted on a car; FIG. FIG. 10, a plan view showing the dimensions of the rotor, is an explanatory diagram of the method previously proposed by the applicant. 1... Rotor 2... Vane groove 4... Backup plate 5b... Die 12... Container 13... Die plate 13... Blank 14... Knockout punch 16... Pressure punch

Claims (1)

[Claims] 1. Insert into a container a blank made of an aluminum alloy for manufacturing an aluminum alloy rotor material in which vane storage grooves are cut inward from the circumferential surface, and Pushing the blank with a pressure punch into a die with a bottom, which has an inner peripheral surface that determines the outer peripheral surface shape of the material and also serves as the base of the fin portion described below, and a fin portion that determines the shape of the vane storage groove, filling a die hole defined by the bottom, inner circumference and fins with the blank, reducing or maintaining the cross-sectional area of the blank substantially the same with respect to the cross-sectional area of the container; In the method for manufacturing an aluminum alloy rotor material, the blank is taken out of the container by operating a knockout punch whose tip surface functions as a part of the die bottom in a direction opposite to the pressing direction of the pressure punch. The fin portion is integrally provided with an extension fin portion extending toward the bottom of the die hole, and the extension fin portion is arranged with or without a gap between at least a part of the circumferential surface of the extension fin portion. A method for manufacturing an aluminum alloy rotor material, characterized in that a backup part having a groove to be inserted is provided, and the sagging of the fin part is prevented by contact between the extended fin part and the groove during processing of the blank. 2. The method for manufacturing an aluminum alloy rotor material according to claim 1, wherein the bottom part of the die is constituted by a backup plate that is fixed integrally with the die or fitted into the die, and the backup plate is used as the backup part. 3. The method for manufacturing an aluminum alloy rotor material according to claim 1, wherein the tip of the die plate holding the die protrudes into the die, and the extension fin is inserted into the bottom of the die. 4. The method for manufacturing an aluminum alloy rotor material according to claim 1, wherein a mold is used in which the inner peripheral surface, the fin portion, and the bottom portion are integrally molded.