JPH09136132A - Die for scroll forming - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the friction resistance between a die and a work during the forging, to reduce the forging load, and to uniformly form a blade of a scroll. SOLUTION: A die for forming a scroll consists of a lower die 1 and an upper die 2. A spiral sinking part 5 is formed on the lower die 1, and the sinking part 5 forms the scroll blade in the forging. The sectional shape of the sinking part 5 is different according to the position in the circumferential direction of the sinking part 5, and a land part is formed on a surface of the lower die 1 in the vertical direction downward of the lower die 1 at the center end and at the terminal end of the outer circumference. A relief part is formed on the lower side of the land part in the vertical direction to the surface of the lower die 1. A straight part is formed downward of the lower die 1 at a middle part of the sinking part in the vertical to the surface of the lower die 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll forming die for a scroll used as a scroll for a scroll compressor, and more particularly, to reduce the frictional resistance between the die and the work material during forging, and the scroll. The present invention relates to a scroll molding die capable of uniformly molding the blades.

[0002]

2. Description of the Related Art As a scroll molding die, there has been proposed a die in which a land portion and a relief portion are formed in a spiral scroll engraving portion (JP-A-4-342887). FIG. 8 is a cross-sectional view showing a scroll forging device, in which the scroll forming die described above is installed. As shown in FIG. 8, the lower die 32 supports the workpiece 31 and shares the reaction force of the forging load,
An upper die 33 is arranged so as to face the lower die 32, and a spiral engraved portion 34 is formed on the upper die 33. The engraved portion 34 has a land portion 34a and a relief portion 34b. The engraved portion 34 forms the scroll blade 40 during forging. An upper die restraint member 35 is disposed above the upper die 33, and the upper die restraint member 35 and the upper die 33 are arranged.
An air vent hole 36 is provided between and. The air vent hole 36 communicates with the carved portion 34. A holder die 37 is arranged around the upper die 33 to support the upper die 33. A constraining die 38 is arranged so as to cover the outer peripheries of the upper die 33 and the lower die 32, and the constraining die 38 restricts the workpiece 31 from extending in the radial direction.

In the scroll forging apparatus thus constructed, as shown on the left side of FIG. 8, after the work material 31 is heated to a predetermined temperature, the lower die 32 and the restraining die 3 are heated.
Insert in 8. Then, the upper die 33 is pressed against the workpiece 31 by a forging press ram (not shown). Upper mold 3
Along with the lowering of 3, the bottom plate portion 41 and the boss portion 42 of the scroll are formed as shown on the right side of FIG. Further, the work material 31 plastically flows into the engraved portion 34 of the upper mold 33, and the flowed work material 31 forms the blades 40 of the scroll. Bottom plate portion 41 and blade 40
After the completion of the molding, the upper mold 33 is raised and the knock-out mechanism (not shown) takes out the scroll molded product from the constraining mold 38 via the lower mold 32.

As shown in FIG. 9, the engraved portion 34 of the upper die 33 has a land portion 34a and a relief portion 34b which are perpendicular to the upper die surface 43.
And the land portion 34a of the escape portion 34b.
The clearance angle α in FIG. 9 is set to an appropriate value. Since the engraved portion 34 is configured in this way, the blade 40 of the obtained scroll molded product is
As shown in, the draft becomes zero. That is, the blade 40 is perpendicular to the bottom plate portion 41, and a scroll molded product with high accuracy can be obtained. Further, as shown in FIG. 9, since the relief portion 34b is provided, the contact area between the workpiece 31 and the engraved portion 34 at the time of processing is reduced, and the frictional resistance is reduced. As shown in FIG. 11, the escape portion 34b
The width of the mold is made longer than the width of the land 34a, and the metal mold having the stepped shape has the same effect as the metal mold of FIG.

[0005]

However, the above-mentioned prior art has the following problems. That is, since the land portion 34a and the relief portion 34b are formed over the entire circumference of the spiral shaped sculptured portion 34, the blade 40 abuts on the upper end of the sculptured portion 34 during the formation of the scroll blade 40, When the molding further proceeds, the escape portion 34b
In addition, there is a problem that the work material 31 is filled and the work material 31 adheres to the engraving portion 34 side at the time of releasing the mold, which makes it difficult to release the work.

Further, after the forging load once rises in the initial stage of casting and molding, the forging load becomes substantially constant regardless of the increase in the forming amount of the blade 40.
The forging load rises sharply when 0 molding reaches the final zone. This increase in forging load has a problem that the dimensional accuracy of the obtained product is reduced and the life of the die is reduced.

In order to avoid the above-mentioned problems, the engraved portion 3
4 It is conceivable to stop the formation of the blades 40 before the blades 40 hit the upper end, but there is a drawback that the heights of the blades 40 of the obtained scroll molded product become uneven.
Further, if the formation of the blades 40 is stopped midway, the forging load does not increase significantly, so that the land portion 34a and the relief portion 34b do not function sufficiently.

The present invention has been made in view of the above problems, and reduces the frictional resistance between the die and the workpiece during forging, reduces the forging load, and uniformly forms the blades of the scroll. An object of the present invention is to provide a scroll molding die that can be manufactured.

[0009]

A scroll forming die according to the present invention is a scroll forming die having a first die having a spiral engraving portion and a second die. The mold part is characterized in that it has a land part provided at a center end and an outer peripheral end part of the carved part and a relief part provided at a bottom part of the land part.

Another scroll forming die according to the present invention is a scroll forming die having a first die having a spiral engraving portion and a second die, wherein the engraving portion is a land. Portion and a relief portion provided at the bottom of the land portion, and the length of the land portion at the center end and the outer peripheral end portion in the depth direction of the engraving portion is the middle portion of the engraving portion. It is characterized in that it is shorter than the length of the land portion in the depth direction.

[0011]

In the scroll forming die according to the first aspect, the land portion and the relief portion are provided at the center end of the engraving portion of the first die and the outer peripheral end portion of the engraving portion of the first die. Has been.
When the work material is pressed by such a first die and the second die, it is possible to reduce the frictional resistance generated between the work material and the center end and the outer peripheral end portion. When the engraved part other than the central end and the outer peripheral end part is referred to as an intermediate part, this frictional resistance is smaller than the frictional resistance generated between the workpiece and the intermediate part. For this reason, when the work material is pressed by the scroll molding die of the present invention, the molding of the scroll blades at the center end and the outer peripheral terminal end is not delayed as compared with the molding of the blades at the intermediate portion. . That is,
The blade forming speed at the center end and the outer peripheral terminal end is substantially equal to the blade forming speed at the intermediate portion. This makes it possible to uniformly form the blade and prevent the forging load from rapidly increasing in the final stage of forming.

In the scroll molding die according to the second aspect, the land portion and the relief portion are provided along the entire circumference of the engraved portion of the first die. However, the length in the depth direction of the land portion at the center end and the outer peripheral end portion of the engraved portion is set to be shorter than the length in the depth direction of the land portion at the intermediate portion. When the work material is pressed by the first mold and the second mold, the friction resistance generated between the work material and the center end and the outer peripheral end portion is reduced. It is smaller than the frictional resistance between the intermediate part and the intermediate part. Therefore, as in the case of the scroll molding die according to the first aspect, the molding of the scroll blades at the center end and the outer peripheral terminal end is not delayed as compared with the molding of the blades at the intermediate portion during the blade molding. .
This makes it possible to uniformly form the blade and prevent the forging load from rapidly increasing in the final stage of forming.

[0013]

EXAMPLES The scroll molding die according to the present invention will be further described below. The inventors of the present application examined the structure of a die in order to reduce the forging load and uniformly form the blades of the scroll. Specifically, a land portion and a relief portion were provided over the entire circumference of the die portion of the die, and the relationship between the blade forming amount and the forging load amount was investigated for this die. FIG.
FIG. 3 is a graph showing the relationship between the blade forming amount (mm) on the horizontal axis and the forging load (ton) on the vertical axis. As shown in FIG. 7, when the blade formation is in the initial stage 51, the forging load increases in accordance with the blade formation. In the middle stage 52 of blade formation, the forging load is substantially constant regardless of the progress of blade formation. Further, it was found that when the blade formation progressed and the final stage 53 was reached, the forging load increased sharply. Initial stage 51,
For each of the middle stage 52 and the final stage 53, when the forging was interrupted and the blade forming state was confirmed, it was found that the blade forming was started in the rising region of the forging load in the initial stage 51. In the middle stage 52, the blade formation was an intermediate stage, and the formed blade was not in contact with the upper end of the engraved portion. Further, in the final stage 53, the stage 53a was a state in which the formed blade started to abut against the upper end of the engraved portion. However, depending on the location of the sculptured part, it was found that there were points where the blade formation was delayed. That is,
The formation of the blade does not proceed uniformly over the entire circumference of the engraved portion, but the formation of the blade is delayed particularly at the center end of the engraved portion and the outer peripheral end of the engraved portion. It has been found that when this blade is formed, the blade already formed hits the upper end of the engraved part and the forging load rises sharply, as shown in step 53b. Therefore, in order to improve the molding speed of the blade and reduce the forging load at the center end of the engraved portion and the outer peripheral end portion of the engraved portion, lands and relief portions are formed at the center end and the outer peripheral end portion.

First, an embodiment (first embodiment) according to claim 1 will be specifically described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a scroll molding die, a material to be molded and a holder mold according to the first embodiment of the present invention. As shown in FIG. 1, a lower die (first die) 1 is provided with a spiral-shaped engraving section 5, and the engraving section 5 forms a scroll blade during forging. An upper die (second die) 2 is arranged above the lower die 1, and a boss forming portion 6 is formed at a substantially central portion of the upper die 2. The holder die 3 is arranged so as to cover the side surface 8 and the edge portion 9 of the lower die 1, and the inner wall 7 of the holder die 3 regulates the workpiece 4 from the outside during forging.

FIG. 2 is a schematic view showing the above-mentioned spiral engraving part 5. 3A is a sectional view showing the AA ′ plane and the BB ′ plane of FIG. 2, and FIG. 3B is the sectional view of FIG.
FIG. 3C is a cross-sectional view showing the −E ′ plane, and FIG.
It is sectional drawing which shows the surface and DD 'surface. A-A 'side, B
The −B ′ surface and the EE ′ surface are oriented toward the advancing direction of the spiral engraving part 5, and the CC ′ surface and the DD ′ surface.
The planes are planes perpendicular to the AA 'plane and the BB' plane, respectively. As shown in FIG. 3, the cross-sectional shape of the sculptured part 5 differs depending on the position of the sculpted part 5 in the circumferential direction. FIG.
As shown in (a), at the center end 23 and the outer peripheral end portion 24 of the engraved portion 5, land portions 26 a are formed in a direction perpendicular to the lower die surface 25 toward the lower side of the lower die 1. ,
An escape portion 27a is formed below the land portion 26a in a direction perpendicular to the lower mold surface 25. The width dimension of the escape portion 27a is longer than the width dimension of the land portion 26a.
Further, as shown in FIG.
In, the straight portion 29 is formed in the direction perpendicular to the lower mold surface 25 toward the lower side of the lower mold 1. That is,
In the intermediate portion 28, no relief portion such as the relief portion 27a is formed, and the side wall of the engraving portion 5 has a draft of 0 ° and is straight. Further, as shown in FIG. 3C, in the cross section of the center end 23 and the outer peripheral end portion 24 of the engraving part 5, the C-C 'plane and the BB' plane perpendicular to the A-A 'plane are perpendicular to each other. In the D-D ′ surface of No. 2, a land portion 26b is formed in a direction perpendicular to the lower mold surface 25 toward the lower side of the lower mold 1, and a land portion 26b is formed below the land portion 26b and perpendicular to the lower mold surface 25. An escape portion 27b is formed in the direction of. The center edge 2
Reference numeral 3 indicates a portion having a length of about 10% of the total length of the spiral of the spiral start portion. Further, the outer peripheral terminal end portion 24 indicates a portion having a length of about 10% of the total length of the spiral of the spiral end portion.

In the scroll forming die having the above-mentioned structure, the workpiece 4 such as an aluminum alloy is preheated to a predetermined temperature and then placed on the lower die 1 inside the inner wall 7 of the holder die 3. Next, the upper die 2 is lowered by a forging press ram (not shown) and pressed against the workpiece 4. Then, as shown in FIG. 4, as the upper mold 2 descends,
The bottom plate portion 10 is formed following the inner wall 7 of the holder die 3, and the boss forming portion 6 of the upper die 2 forms a boss portion 11 on the upper portion of the bottom plate portion 10. Further, the scroll blade 12 is formed by filling the engraved portion (reference numeral 5 in FIG. 1) of the lower die 1 with the workpiece 4 and plastically deforming it. After the molding is completed, the upper mold 2 is raised and the knock-out mechanism (not shown) pushes out the scroll molded product from the lower mold 1 to take it out.

As shown in FIGS. 2 and 3, a land portion 26a and a clearance portion 27a are provided at the center end 23 and the outer peripheral end portion 24 of the engraved portion 5, and the land end 26a and the outer peripheral end portion 24 are provided. Since the frictional resistance between the engraved portion 5 and the workpiece 4 is reduced, this frictional resistance is smaller than the frictional resistance generated in the intermediate portion 28. Therefore, the molding speed of the blades 12 at the center end 23 and the outer peripheral terminal end 24 is increased, and is substantially equal to the molding speed of the blades 12 at the intermediate portion 28. As a result, uniform blades 12 are formed in the scroll molded product, and the forging load is prevented from rapidly increasing in the final step.

Next, an embodiment according to claim 2 (second embodiment)
Will be described. The second embodiment is the same as the first embodiment except that the cross-sectional shape of the engraving part 5 of the first embodiment is different, and therefore the first embodiment shown in FIGS. ), FIG. 3
An explanation will be given using (c) and FIG. 4 as they are. As shown in FIG. 1, also in the second embodiment, the lower mold (first mold) 1
A spiral-shaped engraving part 5 is formed on the upper die 2
The (second mold) is arranged above the lower mold 1. Also,
A boss forming portion 6 is formed substantially in the center of the upper die 2. The holder die 3 is arranged so as to cover the side surface 8 and the edge portion 9 of the lower die 1, and the inner wall 7 of the holder die 3 regulates the workpiece 4 from the outside during forging.

Further, also in the second embodiment, as shown in FIG.
As shown in FIG.
In FIG. 4, a land portion 26a is formed in a direction perpendicular to the lower mold surface 25 toward the lower side of the lower mold 1, and under the land portion 26a, escape in a direction perpendicular to the lower mold surface 25. The part 27a is formed. The width dimension of the escape portion 27a is longer than the width dimension of the land portion 26a. Also,
As shown in FIG. 3C, CC ′ perpendicular to the AA ′ plane
In the D-D 'plane perpendicular to the plane and the B-B' plane, the land portion 26 extends in the direction perpendicular to the lower die surface 25 toward the lower side of the lower die 1.
b is formed, and an escape portion 27b is formed below the land portion 26b in a direction perpendicular to the lower mold surface 25. However, the second embodiment is different from the first embodiment, as shown in FIG. 5, also in the middle part 28 of the engraving part 5 in the direction perpendicular to the lower mold surface 25 toward the lower part of the lower mold 1. Land part 2
6c is formed, and below the land portion 26c,
The escape portion 27c is formed. The width dimension of the escape portion 27c is longer than the width dimension of the land portion 26c. In the second embodiment, the lengths of the central end 23 and the outer peripheral end portion 24 in the depth direction of the land portion 26a are the intermediate portion 28.
The length is shorter than the length of the land portion 26c in the depth direction. The specific lengths of the central end 23 and the outer peripheral end portion 24 are about 1 of the total length of the spiral, as in the first embodiment.
It is about 0%.

In the scroll-molding die having the above-described structure, as in the first embodiment, the workpiece 4 such as an aluminum alloy is preheated to a predetermined temperature, and then the inner wall 7 of the holder die 3 is heated. It is placed on the lower mold 1. Next, the upper die 2 is lowered by a forging press ram (not shown), pressed against the workpiece 4, and forged. Then, since the length of the land 26a of the center end 23 of the engraved portion 5 and the outer peripheral terminal end 24 is shorter than the length of the land 26c of the intermediate portion 28, The frictional resistance generated between the engraved part 5 and the workpiece 4 is reduced. This frictional resistance is
Since it is smaller than the frictional resistance generated in the intermediate portion 28, the molding speed of the blades at the center end 23 and the outer peripheral end portion 24 becomes faster, and is substantially equal to the molding speed 10 of the blades at the intermediate portion 28. For this reason, uniform blades are formed on the scroll molded product, and since the blade formations are substantially the same at each location of the engraved portion 5, it is possible to prevent the forging load from rapidly increasing in the final step.

The length in the depth direction and the length in the circumferential direction of the central end 23 and the outer peripheral terminal end 24 in the above-described first and second embodiments are not uniquely determined. Similarly, the length of the land portion 26c in the depth direction in the second embodiment is not uniquely determined.
These lengths depend on the shape of the scroll (the height of the blades 12,
It is determined in consideration of the outer diameter of the scroll, the wall thickness of the bottom plate portion 10 and the forging conditions (die temperature, temperature of the workpiece 4, die surface roughness, lubricant, etc.). Therefore, the land 26
(26a, 26b and 26c) and the escape portion 27 (27
a, 27b and 27c) are not provided, a lower die 1 is trial-produced, and the workpiece 4 is placed on the lower die 1 and the upper die 2 is pressed as in the above-described embodiments. In this case, the blade 1
Since the forging load rapidly increases before the completion of the molding of No. 2, the molding is interrupted immediately before this increase, and the lacking condition of the center end 23 and the outer peripheral end portion 24 of the engraving part 5 is confirmed. It is preferable to provide the land portion 26 (26a, 26b) in the portion where the thickness deficiency occurs.

Next, the result of actually manufacturing the scroll molded product according to the first and second embodiments will be described in comparison with the comparative example. In the comparative example, the land and the relief portion were not provided in the spirally shaped carving portion, and the lower mold having a straight sidewall having a draft angle of 0 ° was used. FIG. 6 is a graph showing the relationship between the blade forming amount (mm) on the horizontal axis and the forging load (ton) on the vertical axis. As shown in FIG. 6, when a scroll molded product is manufactured using the scroll molding dies of the first and second embodiments, even when the scroll blade 12 is molded at the final stage 53, The forging load did not rise sharply, and uniform blades were formed from the center end 23 of the engraving portion to the outer peripheral end portion 24. On the other hand, in the comparative example, as shown in FIG. 6, when the shaping of the scroll blade reached the final stage 53, the forging load rapidly increased and the shaping of the scroll blade was uneven. From the above results, according to each of the examples, it is possible to produce a scroll molded product even when a forging press having a smaller force than the conventional one is used.

[0023]

As described above, according to the scroll forming die of the first aspect, the forging load is provided because the land portion and the relief portion are provided at the center end and the outer peripheral end portion of the engraving portion. Can be reduced, and the scroll blade can be uniformly formed.

Further, according to the scroll molding die of the second aspect, the length of the land portion at the center end and the outer peripheral terminal end of the engraved portion with respect to the depth direction is the depth direction of the land portion at the intermediate portion. Since it is shorter than the length, the forging load can be reduced and the scroll blade can be uniformly formed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a scroll molding die and a holder die according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a spiral engraving part 5.

3A is a sectional view showing an AA ′ surface and a BB ′ surface of FIG. 2, FIG. 3B is a sectional view showing an EE ′ surface of FIG. 2, and FIG. 3] is a sectional view showing a CC ′ surface and a DD ′ surface of FIG. 2.

FIG. 4 is a cross-sectional view showing a work material, a scroll molding die, and a holder die at the time of forging.

5 is a cross-sectional view showing a EE ′ surface of FIG.

FIG. 6 is a graph showing the relationship between the blade forming amount (mm) on the horizontal axis and the forging load (ton) on the vertical axis.

FIG. 7 is a graph showing the relationship between the blade forming amount (mm) on the horizontal axis and the forging load (ton) on the vertical axis.

FIG. 8 is a cross-sectional view showing a conventional scroll forging device.

FIG. 9 is a cross-sectional view showing a conventional upper mold.

FIG. 10 is a cross-sectional view showing a scroll obtained by using a conventional scroll molding die.

FIG. 11 is a cross-sectional view showing a conventional upper mold.

[Explanation of symbols]

 1, 33; Lower mold 2, 32; Upper mold 3, 37; Holder mold 4, 31; Work material 5, 34; Engraving part 6; Boss forming part 7; Inner wall 8; Side surface 9; Edge part 10, 41 Bottom plate portion 11, 42; boss portion 12, 40; blade 23; center end 24; outer peripheral end portion 25; lower mold surface 26a, 26b, 26c, 34a; land portion 27a, 27b, 27c, 34b; relief portion 28; Intermediate part 29; Straight part 35; Restraint member 36; Air vent hole 38; Restraint mold 43; Upper mold face 51; Initial stage 52; Mid-stage 53, 53a, 53b; Final stage

Claims (2)

[Claims] 1. A scroll molding die having a first die having a spiral shaped die and a second die, wherein the die is a center end and an outer peripheral end of the die. A mold for scroll molding, comprising: a land portion provided in the land and a relief portion provided at a bottom portion of the land portion. 2. A scroll molding die having a first die having a spiral shaped die portion and a second die, wherein the die portion is provided on a land portion and a bottom portion of the land portion. With a relief portion, the length of the land portion in the depth direction of the center end and the outer peripheral end portion of the sculptured portion,
A scroll molding die, wherein the length of the land portion in the middle portion of the engraving portion is shorter than the length of the land portion in the depth direction.