JP3401437B2 - Method of manufacturing tip seal for scroll type compressor and molding apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to a method and a mold apparatus manufacture of Chippushi Le of Spiral Wound used to scroll compressors.

[0002]

As shown in FIG. 6 (a), the scroll type compressor forms a compression chamber 3 by combining a fixed scroll 1 and a movable scroll 2 with each other.
By rotating the movable scroll 2 in an eccentric state, the refrigerant gas is sucked into the compression chamber 3 on the outer peripheral side, and the refrigerant gas is gradually reduced in volume toward the center side and compressed. In this scroll type compressor, a mounting groove 4 as shown in FIG. 6B is provided at the top of the fixed scroll 1 and the movable scroll 2, and a spiral wound tip seal 5 is mounted in the mounting groove 4, and the tip seal is mounted. The airtightness of the compression chamber 3 is maintained by the contact of the inner surface 5 of the mounting groove 4 with the counter scroll.

The chip seal is usually made of plastic and manufactured by injection molding. As this manufacturing method, there is one disclosed in Japanese Patent Laid-Open No. 4-2620887. This is an attempt to spread the plastic material to both ends of the spiral-shaped tip seal by providing a side gate for injecting the plastic material on a side surface of a portion which is an intermediate portion of the entire length of the tip seal.

As described above, in the case where the side gate is provided on the side surface of the chip seal, the molded chip seal is molded integrally with the runner through the gate, so that a step of separating the gate from the chip seal is required. In addition, a gate mark is formed on the side surface of the chip seal, and this gate mark impairs the adhesion to the inner side surface of the mounting groove 4 and impairs the sealability.

In order to prevent the deterioration of the sealing property due to the gate mark, in the technique disclosed in Japanese Patent Laid-Open No. 6-137285, a side gate is provided at the end face portion of the tip end or the end of the tip seal, and the side surface of the tip seal is provided. It is designed to improve the sealing performance by preventing the generation of gate marks.
However, even in this case, the work process of separating the gate is still necessary. Further, since the gate mark remains as a convex portion at the end of the tip seal, the length of the tip seal must be shortened by the length of the convex portion,
The sealing property of that portion is deteriorated, and the compression performance of the compressor cannot be improved.

In order to solve the above problems, the present applicant previously applied for Japanese Patent Application No. 6-308263. This is configured such that a molding die for molding a tip seal is provided with a submarine gate at a position corresponding to an end surface portion of the tip seal, and a plastic material is injected from the submarine gate. According to this, when the die is opened after molding the tip seal, the tip of the submarine gate is automatically sheared and separated from the tip seal, so there is no need for post-processing of the gate treatment, and the gate mark is convex. It does not remain as a.

However, even if the gate is used as a submarine gate in this way, it cannot be denied that the shear mark of the gate remains on the end face of the tip seal, and in order to secure a good sealing property, the shear mark of the end face is machined. There is a problem that it may be necessary to remove it depending on the situation.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to eliminate the need to separate the gate and to prevent a gate mark from occurring on the side surface or the end surface which is the sealing surface. It is an object of the present invention to provide a method of manufacturing a mold and a molding die device.

[0009]

As described above, in the conventional injection molding of a tip seal, it has been a common technique to provide all the gates on the side surface of the tip seal, that is, to form a side gate. Japanese Patent Application No. 6-30826
No. 3 also uses a submarine gate, but the gate injection hole is still provided on the side of the tip seal.

The reason for this is that since the tip seal of the scroll type compressor has a long total length of 60 to 70 cm and has a spiral shape, it has not been considered except to inject a plastic material from the side surface of the tip seal. It was.

[0011]

In view of the present technical circumstances, according to the first aspect of the present invention, the spiral wound tip seal which is mounted in the mounting groove provided in the scroll of the scroll compressor and seals the compression chamber is made of plastic. In a method of manufacturing by injection molding of a material, a gate for injecting a plastic material is formed into a substantially banana shape in a cavity of a mold of the tip seal, and an injection hole of the gate is formed.
Of the inner surface of the cavity, the back surface corresponding to the bottom surface of the mounting groove when the chip seal is mounted in the mounting groove is provided on the surface for molding, and the plastic material is injected from the injection hole into the cavity. The tip seal is molded.

According to a second aspect of the present invention, there is provided a molding die device for manufacturing a spiral wound tip seal, which is mounted in a mounting groove provided in a scroll of a scroll compressor and seals a compression chamber, by injection molding of a plastic material. Provided in one of the first and second molds, and a two-part mold having a cavity for molding the tip seal, the mold being composed of first and second molds. An injection hole for injecting the plastic material into the cavity is provided on the back surface corresponding to the bottom surface of the mounting groove when the chip seal is mounted in the mounting groove, of the inner surface of the cavity. A gate and an ejecting means for ejecting the plastic material solidified in the gate with the mold opened after molding the tip seal. Is shall.

In the tip seal molded by the above manufacturing method and molding apparatus, the banana gate is
Since it is automatically cut when the mold is opened after molding, it is not necessary to cut off the gate as post processing after molding.
In addition, the gate is provided on the back surface of each surface of the tip seal that corresponds to the bottom surface of the mounting groove when it is installed in the mounting groove of the scroll of the compressor. Of the respective surfaces of the seal, this is the back surface that does not adversely affect the sealing property, and therefore it is not necessary to perform finishing processing to eliminate the gate mark.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will now be described with reference to FIGS.
A description will be given based on FIG. Tip seal 11 shown in FIG.
In the scroll compressor shown in FIG.
It is mounted in the mounting groove 4 of the fixed scroll 1 and the movable scroll 2, and is formed in a spiral shape in accordance with the shape of the mounting groove 4, to be precise, an involute curve. The tip seal 11 is formed by injection molding of a plastic material. As the plastic material for injection molding, for example, a thermoplastic material such as PPS mixed with carbon fiber for improving strength is used.

A molding die apparatus for injection molding the tip seal 11 is shown in FIG. In the figure, a molding die 12 is a fixed die 13 as a first die attached to a fixed mounting plate of a molding machine (not shown) and a second die attached to a movable mounting plate of the molding machine. Movable mold 14
It consists of and. A spiral-shaped cavity 15 for molding the chip seal 11 is formed on the mold matching surface of the movable mold 14. The fixed mold 13 is formed with a spool 16 which receives the supply of the molten plastic material from the nozzle of the molding machine, and the movable mold 14 is formed with a runner 17 continuous with the spool 16 on the mold matching surface. The runner 17 and the cavity 15 are connected by a banana-shaped gate (hereinafter, banana gate) 18.

To explain the details of the banana gate 18, the banana gate 18 is mounted on the movable mold 14 so as to be located on the extension of the outer peripheral side end of the cavity 15, as shown in FIG. It is formed in a nest 19 having a split shape. That is, the surface of the insert 19 (mold matching surface)
The tip portion of the runner 17 and the tip portion on the outer peripheral side of the cavity 15 are formed in the portion. And nesting 19
A banana-shaped curved hole that tapers toward the cavity 15 is formed in such a manner that the tip end of the runner 17 formed in the inner part of the runner 17 sunk into the inside of the nest 19, and this banana-shaped curved hole is formed in the banana gate 18. It is said that. Here, in the banana gate 18, the radius of curvature R1 on the outer peripheral side is set to be larger than the radius of curvature R2 on the inner peripheral side, and the center of curvature O1 on the outer peripheral side is set to be larger than the center of curvature 02 on the inner peripheral side. It is located on the side.

As shown in FIG. 5, in the insert 19, the cavity 1 is inserted from the bottom surface of the tip portion on the outer peripheral side of the cavity 15.
5, a protruding portion 19a is formed so as to project into the inside of the base 5, and the tip of the banana gate 18 is positioned corresponding to the protruding portion 19a of the nest 19. The injection hole 18a as a pinpoint gate at the tip of the banana gate 18 is formed so as to penetrate the above-mentioned protrusion 19a, and
An opening is made at the bottom surface of No. 5. The diameter of the injection hole 18a at the tip of the banana gate 18 is as small as about 0.6 mm.

The movable mold 14 has ejector pins 20 as ejecting means for ejecting the plastic material solidified by the runner 17 and ejector pins 21 for ejecting the chip seal 11 molded in the cavity 15.
Is provided. These ejector pins 20, 21
The ejector pin 20 first stops and ejects during the mold opening operation in which the movable die 14 separates from the fixed die 13, and then the ejector pin 21 stops and ejects. There is. The ejector pin 20
A substantially Z-shaped bite portion 20a is formed at the tip of the, and the plastic material solidified by the runner 17 can be extracted from the fixed mold 13 by this bite portion 20a.

In order to mold the tip seal 11 with the molding die device 12 having the above-described structure, when the molten plastic material is injected from the nozzle of the molding machine in the mold closed state shown in FIG. Spool 1
6, the runner 17 and the banana gate 18 are sequentially passed through the injection hole 18a of the banana gate 18 to be injected into the cavity 15 to be filled in the cavity 15.

When the molten plastic material filled in the cavity 15 is cooled and solidified to be molded as the chip seal 11, the movable mold 14 is then opened from the fixed mold 13. At this time, the molded chip seal 11 remains attached to the movable mold 14 and is fixed to the fixed mold 13.
Get away from. Further, the plastic material solidified in the spool 16, the runner 17, and the banana gate 18 (hereinafter,
The solidified plastic P) is also in a state of being bitten by the biting portion 20a of the ejector pin 20, and thus is separated from the fixed mold 13 while being attached to the movable mold 14.

When the movable mold 14 is separated from the fixed mold 13 to some extent, the ejector pin 20 is stopped, and the spool 16 is removed from the solidified plastic P adhering to the movable mold 14 which continues the mold opening operation. It acts to stick out.
Then, since the banana gate 18 is curved so as to be concave with respect to the protruding direction, the solidified plastic P is rotated in the direction indicated by the arrow A in FIG. 4, whereby the injection hole 18a portion is automatically moved. Is cut into pieces, and the portion of the banana gate 18 of the solidified plastic P is the banana gate 1
8 and get the solidified plastic P as a whole movable mold 1
Protruded from 4. After that, since the ejector pin 21 stops, the tip seal 11 is ejected by the ejector pin 21 and separated from the movable mold 14 as shown by the chain double-dashed line in FIG.

As described above, in this embodiment, since the gate for injecting the plastic material into the cavity 15 is the banana gate 18, the gate can be automatically cut when the mold is opened. Therefore, it is not necessary to perform post-processing for separating the gate from the chip seal 11, and the manufacturing cost can be reduced.

Moreover, the solidified plastic P is the runner 1
Since the portion on the 7 side is ejected by the ejector pin 20, it smoothly comes out of the banana gate 18 of the movable mold 14 while rotating, so that the solidified plastic P
It is possible to prevent the jamming of the banana gate 18 by breaking in the middle, and it is not necessary to stop the molding machine to remove the clogged plastic P from the banana gate 18 and contribute to the improvement of productivity. You can

Further, since the injection hole 18a of the banana gate 18 is opened at the bottom surface of the cavity 15, even if the gate mark remains on the chip seal 11, the surface where the gate mark remains is the back surface of the chip seal 11. Therefore, there is no fear that the sealability of the chip seal 11 is impaired by the gate mark, and even if there is the gate mark, a good sealability is exhibited.

Further, the insert 19 is provided with a projection 19a which projects into the cavity 15, and the injection hole 18a.
Is formed on the protrusion 19a, the gate mark is left in the recess 11a formed by the protrusion 19a on the back surface of the chip seal 11. Therefore, even if the gate mark remains as a convex part, it is possible to prevent the gate mark from protruding from the concave part 11a as much as possible, so that it is not necessary to finish the gate mark and the productivity can be further improved.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following modifications and expansions are possible. The position where the banana gate 18 is provided is
The tip seal 11 is not limited to the rear surface on the outer peripheral side, and may be any portion between the start end and the end as long as it is the back surface.
In this case, in particular, in order to easily secure the formation area of the banana gate 18, a range of approximately 360 ° from the end portion on the outer peripheral side toward the center side is preferable.

[Brief description of drawings]

FIG. 1 is a perspective view of a tip seal with a gate immediately after molding, showing an embodiment of the present invention.

FIG. 2 is a sectional view showing the molding die in a mold closed state.

FIG. 3 is a sectional view taken along the line A-A in FIG.

FIG. 4 is a view corresponding to FIG. 2 in a mold open state.

FIG. 5 is an enlarged sectional view of a main part.

FIG. 6 is a sectional view showing the outline of a scroll type compressor.

[Explanation of symbols]

In the figure, 11 is a tip seal, 12 is a mold, 13 is a fixed mold (first mold), 14 is a movable mold (second mold),
15 is a cavity, 16 is a spool, 17 is a runner, 1
Reference numeral 8 is a banana gate, and 20 is an ejector pin (protruding means).

Continuation of front page (56) Reference JP-A-8-1723 (JP, A) JP-A-8-144970 (JP, A) JP-A-4-262087 (JP, A) JP-A-6-137285 (JP , A) JP-A-1-277693 (JP, A) JP-A-6-25645 (JP, A) JP-A-11-351163 (JP, A) JP-A-11-254482 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04C 18/02 311 B29C 45/38

Claims (2)

(57) [Claims] 1. A scroll of a scroll type compressor
It is installed in the mounting groove provided in to seal the compression chamber.
Swirl-shaped tip seal injection molded plastic material
Plastic in the method of manufacturing, the chip mold cavity seal by
The gate that injects the material is formed into an almost banana shape.
The injection hole of the gate is the inner surface of the cavity,
When the tip seal is installed in the mounting groove
The back surface corresponding to the bottom surface of the
Injection of the plastic material into the cavity from
Which is characterized in that the tip seal is molded by
For manufacturing tip seals for chill-type compressors . 2. A molding die apparatus for manufacturing a spiral wound tip seal, which is mounted in a mounting groove provided in a scroll of a scroll compressor and seals a compression chamber, by injection molding of a plastic material . Comprised of two molds, the tip seal
A two-divided forming die having a cavity for forming a mold, and one of the first and second molds.
And inject the plastic material into the cavity
Of the injection hole on the inside of the cavity.
Mounted on the bottom surface of the mounting groove.
With the almost banana-shaped gate provided on the corresponding back surface and the molding die opened after molding the tip seal
A protrusion for ejecting the solidified plastic material in the gate
Scroll type compressor provided with discharge means
Molding device for tip seals .