JPH10328779A - Method for precision-forging scroll member at high working degree and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a scroll which can prevent the unevenness of height of the thin width high rib and the unevenness of a projecting shape of the scroll without requiring a new driving device and also, deteriorating the surface characteristic of the side surface of the rib. SOLUTION: The forging method of this scroll member fills up a forming blank into a forming die having a spiral forming part of almost zero of a draft angle and punches with a forming punch. In such a case, a knockout punch is worked in the opposite direction to the working direction of the forming punch from just before a bottom dead point in the pressing process of the forming punch and the rib tip part of the scroll member is plastic-deformed and also, the knockout punch is worked while following to the forming punch left from the bottom dead point. Further, the rib top part of the scroll member is plastic-deformed and thereafter, the scroll member is removed from the die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forging a scroll member, and more particularly to a method and an apparatus for forging a scroll member having a thin and high rib by pressing.

[0002]

2. Description of the Related Art A scroll member made of an aluminum alloy or steel is used for a compressor or the like constituting an air machine such as an air conditioner, and its shape is shown in FIG. The scroll member 11 includes a spiral rib 12, a head plate 13, and a rotary mounting portion 14. And the scroll member is
It is manufactured by casting, machining or forging.
In the forging method, the fatigue strength of the scroll member can be improved by integrally forming the scroll member (Japanese Patent Application Laid-Open No. 59-1592).
It is also known that the life of the scroll member can be improved. The forging method has the advantage that near net shape molding is possible and the dimensional accuracy is relatively good. Forging methods have come to be frequently used for manufacturing scroll members.

Recently, to reduce the weight and increase the efficiency of the compressor,
There is an increasing demand for a scroll member having a small width and a high rib, that is, a scroll member having a thin and high rib. However, when the scroll member having the thin and high ribs is integrally forged from a disk material by integral forging, the height h of the spiral thin and high ribs tends to be uneven as shown in FIG. There is also a problem that the tip of the thin high rib becomes convex. This problem can be solved by re-forging, but not only involves an increase in new forging equipment but also significantly increases the manufacturing cost of the scroll member. Therefore, as a method of using existing forging equipment, a method has been proposed in which a forging force greater than usual is applied to reduce irregularities in height and irregularities in convex shape.

[0004] However, this method also has a limit in reducing irregularities in rib heights and inconvenience in which the rib ends become convex. In other words, there is a limit to the forging force applied to the mold, and within the limit of the forging force that can be accepted in consideration of the service life of the mold, irregularities in the height of the ribs remain in the unit of mm and the convex shape of the rib tip portion. Cannot be improved. For this reason, it is possible to carry out a second forging for the purpose of sizing in order to correct irregularities in the height of the ribs and the problem of a convex shape at the tip of the rib, but a forging device, a die, There is a problem that a transport device and the like are further required and handling is complicated.

For this reason, various measures have been proposed for preventing the ribs from being irregularly arranged. These are shown below. (A) A method has been proposed in which a relief is provided on a part of the outer periphery of the end plate forming portion or a rib wall portion of the spiral forming portion in a scroll forming die (see Japanese Patent Application Laid-Open Nos. 4-136391 and 4-34287). ). By providing the relief, the unevenness of the height of the thin high ribs is eliminated. (B) In the process of growing a thin high rib of a scroll by pressing, a pressing device having a forming pressurizing power source and another driving source (Japanese Patent Application Laid-Open Nos. 60-102243 and 60-102). No. 102244). At the time of molding or after molding by a pressure device having another drive source, the rib tip is further pressure-molded to correct the irregularity of the rib tip and to make the height of the thin high rib uniform. I'm trying.

(C) After forming the scroll,
A method in which a scroll forged product is removed from a die while pressing a rib tip portion by a spiral extrusion die (Japanese Patent Laid-Open No. 8-57)
572). By using the frictional force between the scroll forging and the mold, the rib tip is pressed when the scroll forging is extracted from the mold, thereby flattening the rib tip. other,
(D) To solve the problem of cracks at the tip of the rib, the insertion speed of the forging material into the recess is controlled by applying pressure to the tip of the material to be inserted by the spiral extrusion die. (See JP-A-5-337586). It discloses that not only an additional drive source but also a spring or an air spring is used to suppress the rib tip.

[0007]

However, (A)
In the method of providing the relief, the unevenness of the height of the thin and high ribs can be partially improved, but the post-processing amount for cutting off the excess thickness increases, and the yield decreases. Further, in the case where the relief is provided on the rib wall, there is a problem that the scroll cannot be removed from the mold. In the case where a device for applying pressure to the rib tip portion in (b) is also provided, although the height of the rib tip can be made relatively uniform, a separate driving source is required in addition to the forming pressure power source, and the device is complicated. This increases the cost and makes the control difficult.

According to the method (c), the scroll forged product is taken out of the die while pressing the rib tip portion, but it is possible to correct the irregularity of the rib tip portion and make the height of the thin and high rib uniform. There is a problem that the surface properties of the rib side surface of the scroll member are deteriorated. In other words, since the pressing of the rib tip is performed when the forged scroll is extracted from the mold,
The frictional force between the scroll forging and the mold will be used. For this reason, it is necessary that the frictional force between the molded scroll forging and the mold is larger than the pressing force required for deformation of the rib tip. For this reason, the frictional force at the time of releasing the rib from the mold is increased, thereby deteriorating the surface properties of the rib side surface.

[0009] The approach speed of the forging material into the recess of (d)
In the method of suppressing by applying pressure to the tip of the material entering by the spiral extrusion die, cracks at the tip of the rib can be prevented. The use of the driving source causes a problem that the apparatus becomes complicated and the cost increases, and the control becomes complicated. Also, when a spring or air spring is used, it is difficult to maintain the balance of the rib tip pressing device, and especially in the case of high-speed forging such as a mechanical press, the pressure response to the rib tip cannot follow. There's a problem.

The present invention has been made to solve the above-mentioned problems of the prior art in order to reduce irregularities in the height of the thin and high ribs of the scroll and irregularities in the convex shapes at the rib tips. That is, without providing a new drive device,
Provided is a scroll manufacturing device capable of preventing irregularities in the height and ribs of the thin and high ribs of the scroll without reducing the surface properties of the rib side surface portion and reducing the finish cutting allowance of the scroll after molding. It is the purpose.

[0011]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, a material to be molded is filled in a molding die having a spiral molding part having a draft of substantially zero. Then, pressurizing with a forming punch, in the forging method for a scroll member, the knockout punch is operated in a direction opposite to the operating direction of the forming punch from immediately before the bottom dead center of the pressing process of the forming punch, so that the tip of the rib of the scroll member is moved. Along with plastic deformation, the knockout punch is activated following the movement of the forming punch away from the bottom dead center, and the rib tip of the scroll member is further plastically deformed, and then the scroll member is released from the mold. It is a feature.

From immediately before the bottom dead center of the pressing process of the forming punch,
The knockout punch is operated in the direction opposite to the operating direction of the forming punch to plastically deform the rib tip of the scroll member, and the knockout punch is operated following the movement of the forming punch from the bottom dead center, and the scroll member is further moved. By plastically deforming the rib tip, the rib tip of a scroll member having a thin high rib is plastically deformed. As a result, a rib having excellent dimensional accuracy can be obtained. At this time, the tip of the rib of the scroll can be flattened by a pressing force that is low enough to be corrected by the knockout punch, so that the load of the forming punch of the scroll member can be reduced and the life of the mold can be improved.
Further, since a large frictional force does not occur between the rib and the mold, the surface properties of the side surface of the rib are not deteriorated. Further, since the knockout punch is operated after the forming punch moves away from the bottom dead center, the scroll member can be relatively easily released from the mold.

According to a second aspect of the present invention, there is provided a scroll member forging apparatus comprising a forming die having a spiral forming part having a draft of substantially zero and a forming punch and a knockout punch. In
A mechanism that operates in the direction opposite to the operation direction of the forming punch from just before the bottom dead center of the pressing process of the forming punch to press the material to be formed, and a knockout punch that follows as the forming punch moves away from the bottom dead center It further comprises a control mechanism that operates and further pressurizes the material to be molded, and then has a mechanism for releasing the scroll member from the mold. The scroll member high precision processing apparatus of the invention according to claim 2 can manufacture a scroll member having excellent dimensional accuracy by a single forging from a material having a simple shape,
Further, the life of the mold can be improved.

According to a third aspect of the present invention, the control mechanism according to the second aspect of the present invention is characterized in that the knockout punch is operated by a cam mechanism interlocked with the pressing process of the forming punch. . The control mechanism is configured to operate the knockout punch by a cam mechanism linked to the pressurizing process of the forming punch, so that the scroll member with excellent dimensional accuracy can be manufactured by the function of the single-acting press. Can be improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to illustrated examples. FIG. 1 is a diagram showing an operating state of a forming punch and a knockout punch of a forging device according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a forming die and a periphery thereof of the forging device of the embodiment of the present invention. FIGS. A to f show a state in which the material to be molded is forged into a scroll member, and FIG. 3 is a view showing a processing state of a rib tip portion of the scroll member.

First, the configuration of a forging device according to an embodiment of the present invention will be described with reference to FIG. 2 (FIG. A). The forging apparatus of the present invention includes a molding die 2 having a spiral rib forming portion 3.
, A forming punch 4 and a knockout punch 5. The spiral forming part 3 of the molding die 2 is formed in a spiral groove shape in order to form the material to be molded 1 into a spiral rib of the scroll member 11, and the depth of the spiral rib forming part 3 is formed. In the vertical direction, the gradient is substantially zero. That is, the draft was set to 0 ° (including approximately 0 °). The knockout punch 5 has a structure capable of moving vertically in the spiral rib forming portion 3 of the molding die 2 and has the same spiral shape as the scroll member to be molded. The spiral-shaped thickness of the knockout punch 5 is smaller than the width of the rib forming portion 3 of the molding die 2. Further, the knockout punch 5 is attached to a knockout punch guide section 6, and the knockout punch guide section 6 is driven by a cam interlocking mechanism 7.

Here, an outline of a forging method according to an embodiment of the present invention will be described with reference to FIG. The upper curve in FIG. 1 is a curve indicating the stroke of the forming punch, and the lower curve is a curve indicating the stroke of the knockout punch. From the start of forging Ta, the forming punch descends and press-forms the material to be formed.
When the bottom dead center (time Tc) is reached, the forming punch rises. On the other hand, in the knockout punch, the knockout punch rises from the time Tb immediately before the bottom dead center in the pressing process of the forming punch. In the vicinity of the bottom dead center of the forming punch, the knockout punch reaches the material to be formed, that is, the tip of the rib of the scroll member. This situation is shown in FIG. 3 (FIG. A).

As shown in FIG. 3 (FIG. A), the height of the ribs of the scroll member being processed in the rib forming portion of the molding die is not uniform, and the height variation ΔH is on the order of several mm. Has become. This means that during forging,
This is because it is difficult to make the material to be plastically flowed uniformly. The tip of the rib has a convex shape, and the convex height Δh of the tip of the rib is on the order of 0.1 mm.

In the present invention, as shown in FIG.
The rib tip is pressurized by a knockout punch to plastically deform the rib tip, and the rib tip is shaped flat. Further, the plastic flow at the tip of the rib in the rib forming portion of the molding die is controlled by the knockout punch so as to have a predetermined rib height. in this case,
Since it is sufficient to form the ribs so that only the rib tip is corrected, the load of the knockout punch is much smaller than that of the forming punch.

For this reason, as shown in FIG.
(Lower dead center of the forming punch), the rising speed of the knockout punch is made faster than the rising speed of the forming punch. That is, the rising stroke distance ΔL2 of the knockout punch is set larger than the rising stroke distance ΔL1 of the forming punch from time Tc (bottom dead center of the forming punch) to time Td (パ ン チ L
1 <△ L2). As a result, the tip of the rib of the scroll member is plastically deformed by the distance of (△ L2 △△ L1).

After the time Td, the rising speed of the forming punch becomes faster than the rising speed of the knockout punch, and the formed scroll member is released from the forming die. Can be performed, for example, by controlling a punch stroke of a cam mechanism.

Next, a thin and high rib (for example, a rib width: 3.5 mm, a rib height: 30 mm) in the forging device of the present invention.
Fig. 2 shows a high-precision precision forging method for scroll members with
This will be further described with reference to FIG.

As shown in FIG. 2 (FIG. A), a material 1 to be molded heated to a temperature suitable for forging is set in a molding die 2. The material to be molded 1 is structured to be restrained by a scroll member molding support 8. At this time, the forming punch 4 is in a state immediately before the start of lowering.

In the process from FIG. 2 (FIG. 2A) to FIG. 2 (FIG. 2B), the forming punch 4 descends, and the forming punch 4 comes into contact with the material 1 to be formed. When the forming punch 4 further descends, the material 1 is pressurized and plastically deformed. It is pushed by. Then, the forming punch 4 in FIG. 2 (FIG. 2B) is in a state of descending just before the bottom dead center. In the process from FIG. 2 (FIG. 2A) to FIG. 2 (FIG. 2B), the rotary mounting portion of the scroll member is formed by the end plate forming portion 9 of the forming punch 4. On the other hand, the rib of the scroll member is being formed in the rib forming portion 3 of the molding die 2. The state of the formation of the rib is the state shown in FIG. 3 (FIG. A) as described above.

Next, in the process from FIG. 2 (FIG. 2B) to FIG. 2 (FIG. 2C), the knockout punch 5
To start rising. At this time, the forming punch 4 continues to be lowered, and the knockout punch 5 rises to face the material 1 in the rib forming portion 3 of the forming die 2, that is, the rib tip. Until the forming punch 4 reaches the bottom dead center, the tip of the rib is pressed by the knockout punch 5 to locally form the tip of the rib. Then, the forming punch shown in FIG. 2 (FIG. 2C) reaches the bottom dead center. At this time, it is preferable that the knockout punch 5 and the rib tip are all in contact with each other. Therefore, the position of the knockout punch at the bottom dead center of the forming punch is adjusted in advance in consideration of the variation ΔH of the height of the rib of the scroll member.

Next, the forming punch 4 starts to move upward, and the knockout punch 5 and the forming punch 4 move upward in conjunction with each other.
At this time, the difference (ΔL2) between the ascending stroke distance ΔL2 of the knockout punch and the ascending stroke distance ΔL1 of the forming punch until the release of the formed scroll member from the rib forming portion 3 of the forming mold 2 is started. − △ L1) is determined from the convex height △ h of the rib tip measured in advance. At this time, FIG.
As shown in FIG. 4 (d), the rib tip is pressurized by the knockout punch 5 to plastically deform the rib tip to form the convex shape of the rib tip flat and to adjust the rib height to a predetermined rib height. Control so that it becomes the height. Note that (△ L2
By reducing-△ L1), the required forming load of the knockout punch can be reduced.

In the process, the rising speed of the forming punch 4 becomes faster than the rising speed of the knockout punch 5, and the forming punch 4 separates from the workpiece 1. This state is shown in FIG.
(Figure e). Further, as the process proceeds, the knockout punch 5 rises, and the workpiece 1 is knocked out of the molding die 2. This state is shown in FIG. 2 (FIG. F).

As described above, according to the forging apparatus and the forging method of the present invention, the pressurizing process of the forming punch is performed after the material to be formed reaches a substantially full state in the rib forming portion of the forming die under a normal load. In the period from just before the bottom dead center until the forming punch separates from the forming material, the forming material is pressure-formed by both the forming punch and the knockout punch. In particular, the present invention suppresses variations in the height of the thin-width and high-rib molding material by pressure molding of the knockout punch, and flattens the rib tip. At this time, since local shaping is sufficient to correct the rib tip, the overall maximum load can be small. For this reason, forging by a large press can be avoided, and the load on the mold can be significantly reduced.

In the embodiment of the present invention, the variation in the height of the ribs is suppressed and the tip of the ribs is flattened by controlling the cam interlocking mechanism of the knockout punch. By modifying existing equipment, especially the cam mechanism of a single-acting press, it is possible to suppress variations in rib height and to flatten the rib tip. Further, the control of the operation of the knockout punch can be applied not only to the cam interlocking mechanism but also to the case where the knockout punch is operated by hydraulic pressure or a mechanical device or the like, and these also belong to the technical scope of the present invention. .

[0030]

[Example] Thin and high ribs (rib width: 3.5 mm, aluminum alloy (material: aluminum alloy containing high Si))
The forging (forging temperature: 400 to 500 ° C.) of the scroll member having a rib height of 30 mm) was performed by a single-acting press that operates a knockout punch by a cam mechanism of a single-acting press interlocked with a pressing process of a forming punch. . At this time, the cam mechanism of the single-acting press operates as a forming punch and a knockout punch as shown in FIG.
A cam processed into a shape was used.

The shape of the cam used for the cam mechanism is as follows: the height variation of the conventional rib of the scroll member having the thin and high rib used in the embodiment of the present invention ΔH: 2 mm; Height Δh: 0.5 mm, especially determined in consideration of the convex height of the rib tip. The difference (△ L2- △ L1) between the rising stroke distance ΔL1 of the forming punch from the bottom dead center of the forming punch and the rising stroke distance ΔL2 of the knockout punch is △.
h / 2 + α. α takes into account the variation in the convex shape at the tip of the rib. In this embodiment, α is 0.1 m
m, and (△ L2- △ L1) was set to 0.15 mm.

A scroll member having a thin and high rib was forged by a single-acting press that operates a knockout punch by a cam mechanism interlocked with the pressing process of the forming punch. As a result, the variation of the rib height ΔH is 0.1
mm, and the convex height Δh of the rib tip is also 0.2
mm, and a scroll member having excellent dimensional accuracy could be manufactured. The mold life at this time was equal to or longer than the conventional mold life.

In the conventional method, when the forming load of the forming punch is increased to near the limit (for example, the forming load of the forming punch is 1.7 times as large as that of the related art), the variation in the height of the ribs ΔH
Can be improved to about 0.2 mm, but the convex height Δh of the rib tip remains unchanged at 0.5 mm, and the dimensional accuracy of the scroll member having the thin and high ribs cannot be improved.

In this embodiment, an aluminum alloy containing high Si is used. However, the present invention is not limited to this. Other aluminum alloys and other metal materials (iron and steel materials,
Copper alloy) can also be used. Further, in the present embodiment, the rib height variation ΔH is reduced by plastically deforming the tip of the rib between immediately before the bottom dead center of the forming punch and the bottom dead center. Although suppressed, the variation ΔH in the height of the rib can also be suppressed by plastically deforming the tip of the rib in the process before and after the bottom dead center of the forming punch. These are also within the technical scope of the present invention.

[0035]

As described above, a rib having excellent dimensional accuracy can be obtained by using the apparatus or the method for precision forging of a scroll member according to the present invention. As a result, there is an effect that the finish cutting allowance of the scroll after molding can be reduced. In particular, it is possible to suppress the convex height Δh at the tip of the rib, which was difficult with the conventional method. Further, there is an effect that a rib having good surface properties can be obtained without requiring a large frictional force between the rib and the mold.

Further, in the high precision precision forging apparatus for a scroll member according to the present invention, the control mechanism is configured to operate the knockout punch by a cam mechanism interlocked with the pressurizing process of the forming punch, so that another driving source is provided. There is an effect that a scroll member having excellent dimensional accuracy can be manufactured by the function of the single-acting press without the need.

[Brief description of the drawings]

FIG. 1 is a diagram showing an operating state of a forming punch and a knockout punch of a forging device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a die of a forging device according to an embodiment of the present invention and a periphery thereof. FIG. 2A shows a state in which a material to be molded is placed on a molding die, and a molding punch starts to descend. FIG. B is a diagram showing a state at the time, FIG. B is a diagram showing a state in which the forming punch is lowered just before the bottom dead center, and a state in which the knockout punch starts to rise, and FIG. It is a diagram showing a state in which the knockout punch continues to rise in the state reached, FIG.d is a diagram showing a state in which the knockout punch continues to rise as the forming punch rises and separates from the workpiece, FIG. E shows that the forming punch is completely separated from the material to be formed, and the knockout punch 5
Is a diagram showing a state in which the molding material is being knocked out of the molding die by raising the molding material, and FIG. F is a diagram showing a state in which the molding material 1 is completely knocked out of the molding die.

FIG. 3 is a diagram illustrating a processing state of a rib tip portion of a scroll member, and FIG. A is a diagram illustrating a processing state of a rib tip portion in a molding state in which a molding punch is lowered to a vicinity of a bottom dead center;
FIG. B is a view showing a state where the forming punch reaches the bottom dead center and the knockout punch keeps rising.

FIG. 4 is a view showing a shape of a scroll member, and FIG.
Is a plan view of the scroll member as viewed from above, and FIG. B is a cross-sectional view of the scroll member at XX.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 molded material 2 molding die 3 molding die rib forming portion 4 molding punch 5 knockout punch 6 knockout punch guide portion 7 cam interlocking mechanism 8 scroll member molding support 9 molding plate end portion of molding punch 11 scroll member 12 Rib 13 End plate 14 Rotating mounting part H Height of rib H Height of convex shape of rib tip part

Claims (3)

[Claims] 1. A forging method for a scroll member, wherein a material to be molded is filled in a mold having a spiral rib forming part having a draft of substantially zero, and is pressed by a forming punch. Immediately before the bottom dead center, the knockout punch is operated in the direction opposite to the operating direction of the forming punch to plastically deform the rib tip of the scroll member, and the knockout punch is operated as the forming punch moves away from the bottom dead center And further deforming the tip of the rib of the scroll member plastically, and then releasing the scroll member from the mold. 2. A forging device for a scroll member comprising a forming die having a spiral rib forming portion having a draft of substantially zero, a forming punch and a knockout punch, wherein the knockout punch includes a lower die in a pressing process of the forming punch. A mechanism that presses the material to be molded by operating in the direction opposite to the operating direction of the forming punch immediately before the point, and a knockout punch that activates the knockout punch following the movement of the forming punch from the bottom dead center, further A high-precision processing apparatus for a scroll member having a control mechanism having a mechanism for applying pressure and then releasing the scroll member from a mold. 3. The apparatus according to claim 2, wherein the control mechanism operates the knockout punch by a cam mechanism interlocked with a pressurizing process of the forming punch.