JP2008284847A - Molding die for annular gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding die for an annular gasket which is capable of manufacturing the gasket of high dimensional precision inexpensively and massively. <P>SOLUTION: The molding die 20 forms a gasketlike space GS by a fixed die 21, a movable die 22 and a gate die 23. A resin injection port 31 for injecting a molten resin into the gasketlike space GS is made an annular slit by the fixed die 21 and the gate die 23, while a lead-out passage P which is formed by the fixed die 21 and the gate die 23 and connected to the resin injection port 31 formed in the shape of the annular slit is tapered toward the resin injection port 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a molding die for an annular gasket.

  With the further miniaturization of small precision instruments incorporating coin-type electrochemical cells, such as coin-type secondary batteries and coin-type capacitors, the coin-type electrochemical cells themselves will be further reduced in size, thickness and capacity. Is requested. In addition, with the reflow soldering of circuit boards incorporating coin type electrochemical cells, the coin type electrochemical cells themselves are required to have heat resistance for reflow soldering.

  Generally, a coin-type electrochemical cell contains electrochemical elements in a metal positive electrode can and negative electrode can, combines the positive electrode can and the negative electrode can through a resin gasket, and covers the folded portion of the negative electrode can. The positive electrode can is sealed by bending and caulking the opening.

  Since these annular gaskets are required to have a sealing function as an electrochemical cell, mechanical properties after caulking, that is, compression properties after gasket compression, creep properties after compression, solution resistance, and insulation are required. Generally, a resin material is used. There are various methods for molding these resin materials into gaskets, but in coin-type electrochemical cells, mass production is emphasized, and injection molding is common.

  By the way, in recent years, engineering plastics having heat resistance have been used from polypropylene (PP) which has been conventionally used by reflowing electrochemical cells. These engineering plastics have poorer resin fluidity in injection molds than conventional polypropylene (PP) and the like, and injection molding is becoming difficult.

  For this reason, the resin injection port to the gasket uses a disk gate method using a disk-shaped injection port at the center of the gasket instead of the conventional pin gate method using a small hole (for example, Patent Document 1 and Patent Document 2). .

  As shown in FIG. 6A, the disk gate type molding die 50 forms a gasket-shaped space GS with a fixed die 51, a movable die 52, and a gate cut pin 53. When molten resin is injected from the resin injection port 51 a of the fixed mold 51 into the disk gate portion 54, which is a space formed by the fixed mold 51 and the gate cut pin 53, the resin flows into the disk gate portion 54. Flows in the circumferential direction from the center of the gasket-shaped space GS. Thereby, a uniform pressure can be applied to the gasket resin 55 filled in the gasket-shaped space GS. Then, by separating the disc resin 56 filled in the disc gate portion 54, a gasket resin 55 having a predetermined shape can be obtained. That is, when the gasket resin 55 is obtained by separating the disc resin 56, the movable mold 52 is driven in the direction of the arrow with respect to the fixed mold 51 and the gate cut pin 53 as shown in FIG.

  At this time, when the movable mold 52 moves, the clearance between the bottom 55a of the gasket resin 55 and the fixed mold 51 is generated by the thickness of the disk resin 56, so that distortion caused by the cutting of the disk resin 56 occurs. At the bottom 55a. Due to this distortion, there is a problem that the bottom 55a of the gasket resin 55 is deformed and the dimensional accuracy of the gasket is lowered.

Therefore, a film gate method has been proposed in order to reduce distortion during separation (for example, Patent Document 3).
As shown in FIG. 7A, the film gate type molding die 60 forms a gasket-shaped space GS filled with the gasket resin 65 with the fixed die 61, the movable die 62, and the gate cut pin 63. The outer peripheral portion of the disk gate portion 64, which is a space formed by the fixed mold 61 and the gate cut pin 63, that is, the connection portion 64a (film gate portion) connecting the disk gate portion 64 and the gasket-shaped space GS is thinned. It is a method to do. 7B, after opening the movable mold 62 with respect to the fixed mold 61, the gate cut pin 63 is driven to cut the thin portion of the disk resin 66 from the gasket resin 65. . By cutting the thin portion, the distortion applied to the gasket resin 65 caused by the cutting of the disk resin 66 is reduced.
JP-A-50-145822 (Page 2) JP 2002-75303 A (2nd page) Japanese Patent Laid-Open No. 55-15834

  However, although the film gate method reduces distortion as much as the thin portion of the disk resin 66 is cut compared to the disk gate method, the bottom 65a of the gasket resin 65 is instantly cut off at the moment when the disk resin 66 is cut off. Therefore, as in the case of the disc gate system, the disc resin 66 is detached, and the bottom portion 65a of the gasket resin 65 is distorted, and the bottom portion 65a of the gasket resin 65 is deformed to reduce the dimensional accuracy of the gasket.

  In addition, since the film gate type and disk gate type injection molding machines need to be provided with a mechanism (gate cut pin) for cutting the disk resins 56 and 66 from the gasket resins 55 and 65, the injection molding machine and the mold structure Both were complicated.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a molding die for an annular gasket capable of manufacturing a gasket with high dimensional accuracy at low cost and in large quantities. It is in.

  According to the first aspect of the present invention, the molten resin is injected into a gasket-shaped space formed by the first mold and the second mold, and then the first mold and the second mold are separated. An annular gasket molding die for molding an annular gasket with a gasket resin filled in the gasket-shaped space, and an injection port for injecting molten resin into the gasket-shaped space has an annular shape in the gasket-shaped space. An annular slit was formed between the first mold and the second mold so that the molten resin was injected from the position corresponding to the entire inner circumference of the bottom of the gasket, and the annular slit was formed. A lead-out passage formed by the first mold and the second mold connected to the injection port was formed to be tapered toward the injection port.

According to a second aspect of the present invention, in the annular gasket molding die according to the first aspect, the annular gasket is a coin-type electrochemical cell gasket.
According to a third aspect of the present invention, in the molding die for an annular gasket according to the first aspect, an annular protrusion is formed on the opening edge of the inlet formed in the annular slit so as to protrude toward the gasket-shaped space. Has been.

According to a fourth aspect of the present invention, in the molding die for an annular gasket according to the third aspect, a slit width of an injection port formed in the annular slit is 0.07 mm to 0.25 mm, and the annular gasket is formed. The inclination angle of the tapered lead-out passage toward the inlet formed in the slit is 45 degrees to 80 degrees, and the width of the annular protrusion is 0.03 mm to 0.1 mm.

  According to a fifth aspect of the present invention, in the molding die for an annular gasket according to any one of the first to fourth aspects, the resin injected into the gasket-shaped space is a polyphenylene sulfide resin (PPS) or a polyether ether ketone resin. It is a resin material composed of at least one of (PEEK), liquid crystal polymer (LCP), polyether nitrile resin (PEN), polyamide resin (PA), and polyimide resin (PI).

  According to the first aspect of the present invention, the molten resin flows radially from the position corresponding to the entire inner circumference of the bottom of the annular gasket in the circumferential portion of the gasket-shaped space to the gasket-shaped space. The gasket resin to be filled is filled while applying a uniform pressure. Moreover, since the molten resin is directly injected into the gasket-shaped space from the injection port formed in the annular slit, there is no conventional gate such as a disk gate or a film gate.

  In addition, a lead-out passage connected to the injection port is formed in a tapered shape toward the injection port. Therefore, when the first mold and the second mold are released, the resin in the injection port remains in place without being drawn out, so that the gasket-shaped space is filled at the injection port and simultaneously with the release. Separated from the gasket resin. At this time, the lead-out passage is tapered toward the injection port, and the slit width of the injection port can be reduced, and the force applied to the solidified gasket resin is separated from the mold release. This suppresses the occurrence of distortion at the bottom of the gasket resin, and increases the dimensional accuracy of the gasket.

  Furthermore, since the resin in the inlet can be separated from the gasket resin simply by releasing the first mold and the second mold, it is necessary to add a complicated mechanism to the molding machine for the separation. Therefore, it is possible to perform molding with an inexpensive injection molding machine and molding mold structure, and it is possible to shorten the cycle time of gasket manufacturing and improve productivity.

According to the invention of claim 2, a coin type electrochemical cell gasket having high dimensional accuracy can be produced at low cost and in mass production.
According to invention of Claim 3, since the part cut | disconnected easily increases by forming the cyclic | annular protrusion, it becomes easy and reliable.

According to invention of Claim 4, a gasket with few burrs and sink marks and a small defect rate can be manufactured.
According to invention of Claim 5, the gasket excellent in heat resistance can be manufactured.

(First embodiment)
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
First, an annular gasket used for a coin-type electric double layer capacitor as a coin-type electrochemical cell will be described with reference to FIG.

  FIG. 1 is a schematic cross-sectional view of a coin-type electric double layer capacitor (hereinafter referred to as a capacitor). In FIG. 1, a capacitor 1 includes a stainless steel bottomed cylindrical positive electrode can 2 and a stainless steel covered cylindrical negative electrode can 3. The negative electrode can 3 has a circular opening folded back, and an annular gasket (annular gasket) 4 is attached to the folded opening 3 a.

  Then, the negative electrode can 3 is fitted into the circular opening 2a of the positive electrode can 2 from the opening 3a side where the gasket 4 is mounted, and the opening 2a of the positive electrode can 2 is caulked toward the gasket 4 to seal it. Thus, the positive electrode can 2 and the negative electrode can 3 are connected and fixed to each other. By connecting and fixing the positive electrode can 2 and the negative electrode can 3, a sealed space is formed between the positive electrode can 2 and the negative electrode can 3 via the gasket 4.

  In this sealed space, the positive electrode 5, the separator 6, and the negative electrode 7 are accommodated, and the positive electrode 5 is accommodated on the positive electrode can 2 side and the negative electrode 7 is accommodated on the negative electrode can 3 side with the separator 6 interposed therebetween. This sealed space is filled with the electrolytic solution 8.

  Since the positive electrode can 2 and the negative electrode can 3 also serve as the positive electrode terminal and the negative electrode terminal and must be sealed by caulking the cans 2 and 3, generally a metal material (for example, stainless steel) is used. It has been.

  The gasket 4 has a caulking structure and can hold the electrolyte 8 filled in the capacitor 1 inside. Further, the gasket 4 does not cause leakage by continuously applying sufficient surface pressure to the positive electrode can 2 and the negative electrode can 3, and reflow heating. Resin materials that satisfy the heat resistance of the time are used. Resin materials that satisfy this condition include polyphenine sulfide resin (PPS), polyether ether ketone resin (PEEK), liquid crystal polymer (LCP), polyether nitrile resin (PEN), polyamide resin (PA resin), polyimide resin ( Engineering plastics such as PI) are used as resin materials for gaskets.

  As shown in FIGS. 2A and 2B, the gasket 4 is formed in an annular shape and is formed in a U-shaped cross section, and has an outer peripheral wall portion 11, an inner peripheral wall portion 12, and a bottom wall portion 13. An annular groove 14 surrounded by the walls 11, 12, 13 is formed.

  In this embodiment, the gasket 4 has an outer diameter of 4.5 mm, an inner diameter of 3.0 mm, a thickness of the gasket 4 of 0.2 mm, and a bottom (bottom wall 13) having a thickness of 0.3 mm. It is a gasket.

  The positive electrode 5 is disposed on the bottom surface 2 b of the positive electrode can 2. In the present embodiment, the positive electrode 5 is composed of an activated carbon sheet. A separator 6 is disposed above the positive electrode 5. The separator 6 is made of glass fiber and impregnated with the electrolytic solution 8. A negative electrode 7 is disposed on the upper side of the separator 6. Similarly to the positive electrode 5, the negative electrode 7 is composed of an activated carbon sheet. The sealed space that accommodates the positive electrode 5, the separator 6, and the negative electrode 7 is filled with an electrolytic solution 8. As the electrolytic solution 8, for example, propylene carbonate was used as a solvent and tetraethylammonium tetrafluoroborate was used as a solute.

Next, the manufacturing method of the gasket 4 is demonstrated.
FIG. 3 shows a cross-sectional view of the main part of a film ring gate type injection mold for molding the gasket 4.

  As shown in FIG. 3, an injection mold 20 includes a fixed mold 21 as a first mold, a movable mold 22 that constitutes a second mold, and a gate mold that constitutes a second mold. 23. The gasket-shaped space GS is formed by the fixed mold 21, the movable mold 22, and the gate mold 23.

The fixed mold 21 forms the outer surface 11 a of the outer peripheral wall portion 11 of the gasket 4 and the outer surface 13 a of the bottom wall portion 13. The movable mold 22 moves so as to be able to contact and separate from the fixed mold 21. The movable mold 22 forms the inner surface of the groove portion 14 of the gasket 4 and forms the upper surface 11 b and 12 b of the outer peripheral wall portion 11 and the inner peripheral wall portion 12. The gate mold 23 moves integrally with the movable mold 22. The gate mold 23 molds the outer surface 12 a (the inner peripheral surface of the gasket 4) of the inner peripheral wall portion 12 of the gasket 4.

  The fixed mold 21 has a resin injection port 31 at the center position. The inner diameter of the inner peripheral surface 31a of the resin injection port 31 becomes larger toward the back. An annular protrusion 32 is formed to extend from the opening edge of the resin injection port 31 of the fixed mold 21. As shown in FIG. 4, the inner peripheral surface 32 a of the protrusion 32 is a cylindrical surface and is connected to the inner peripheral surface 31 a of the resin injection port 31. The outer peripheral surface 32b of the ridge 32 is formed in a truncated cone-shaped inclined surface, and the tip surface 32c is formed in an annular plane.

The gate mold 23 has a tip portion 41 formed in a truncated cone shape so as to enter the resin injection port 31 of the fixed mold 21. The distal end portion 41 of the gate mold 23 has a small diameter portion 41a whose proximal end is smaller in diameter than the outer diameter of the gate mold body 23a, and has a reduced diameter portion 41b that tapers from the small diameter portion 41a toward the distal end. ing. In the present embodiment, the tip of the small diameter portion 41a is positioned on the extension line of the tip surface 32c of the protrusion 32 when the gasket-shaped space GS is formed. At this time, an annular slit SR is formed between the inner peripheral surface 32a of the protrusion 32 and the outer peripheral surface of the small diameter portion 41a, and the reduced diameter portion 41b of the gate mold 23 and the resin injection port of the fixed mold 21 are formed. 31 and a lead-out passage P is formed,
Then, as shown in FIG. 5A, the molten resin is injected into the gasket-shaped space GS through the lead-out passage P.

  At this time, the radially melted resin flows from the entire circumference of the gasket-shaped space GS, and the resin can be filled while applying a uniform pressure to the resin filled in the gasket-shaped space GS. In addition, since the molten resin is directly injected into the gasket-shaped space GS from the outlet passage P (slit SR), there is no gate such as a conventional disk gate or film gate.

  In addition, the lead-out passage P is larger as the inner diameter of the inner peripheral surface 31a of the resin injection port 31 becomes deeper, and the tip 41 of the gate mold 23 is formed in a truncated cone shape. The cross-sectional shape becomes tapered toward the gasket shape space GS (slit SR), that is, a wedge shape.

  As shown in FIG. 5B, when the movable mold 22 and the gate mold 23 are released from the fixed mold 21, the resin solidified in the lead-out path P is not drawn out. Stay in play. As a result, the gasket resin R (gasket 4) filled in the gasket-shaped space GS is separated from the resin remaining in the outlet passage P at the slit SR.

  Incidentally, if the slit width W of the slit SR formed in the lead-out passage P is too small, the resin pressure cannot be sufficiently increased during the resin filling, and the gasket density varies or the resin filling error occurs. If it is too large, a large amount of burrs remain when separating the fixed mold 21 and the gasket resin R (gasket 4), and the burrs pop out from the bottom wall portion 13 of the gasket 4 to deteriorate the sealing performance of the capacitor 1. Let

Accordingly, the slit width W of the slit SR formed in the lead-out passage P is preferably in the range of 0.07 mm to 0.25 mm.
Further, if the inclination angle A of the tapered lead-out passage P, that is, the angle formed by the outer surface 13a of the bottom wall portion 13 of the gasket 4 and the inclined surface 42 of the reduced diameter portion 41b of the gate mold 23 is too small, Burrs generated when the resin at the resin injection port 31 (lead-out passage P) and the gasket resin R are separated from each other in the circumferential direction of the gasket 4 to deteriorate the sealing performance of the battery. On the other hand, if the inclination angle A is too large, the resin pressure cannot be concentrated well at the resin injection port 31 (outlet passage P), and sufficient pressure cannot be applied to the gasket resin R at the time of resin filling, and the gasket 4 Density inhomogeneity or filling error of the gasket resin R occurs. Therefore, the inclination angle A is preferably in the range of 45 to 80 degrees.

  Furthermore, if the width (edge width L) of the annular tip surface 32c of the protrusion 32 formed on the fixed mold 21 is too small, burrs are likely to occur. Therefore, the edge width L is preferably in the range of 0.03 mm to 0.1 mm.

Therefore, a gasket manufactured by changing various conditions of the molding die was verified.
Example 1
Example 1 is a molding die 20 shown in FIG. 3, and the slit width W is 0.1 mm, the inclination angle A is 50 degrees, and the edge width L is 0.05 mm.

  The gasket 4 is a J-type gasket having an outer diameter of 4.5 mm, an inner diameter of 3.0 mm, a gasket thickness of 0.2 mm, and a bottom thickness of 0.3 mm. As the resin to be injected, polyether ether ketone (PEEK) with 10% glass filler was used.

And the gasket 4 was injection-molded, and the deformation of the outer surface 13a of the bottom wall portion 13 of the gasket 4 was measured by the difference in the bottom surface unevenness using a three-dimensional shape measuring machine using a laser. The test evaluation results are shown in Table 1.
(Reference Example 1)
Reference Example 1 is a molding die 50 shown in FIG. 6, in which resin is injected from a disk gate portion 54 having a thickness of 0.3 mm inside the gasket resin 55, and the disk resin 56 is fixed from the gasket resin 55 to the fixed die 51. Then, the movable mold 52 was moved with respect to the gate cut pin 53 to separate it, and a gasket was produced.

The shape of the gasket resin 55, the resin used, and the method of deforming the gasket bottom are the same as in the first embodiment. The results are shown in Table 1.
(Reference Example 2)
Reference Example 2 is a molding die 60 shown in FIG. 7, in which a resin is injected into a gasket resin 65 from a disk gate portion 64 (film gate portion) having a thickness of 0.05 mm, and a thin portion of the disk resin 66. Was cut by moving the gate cut pin 63.

  The shape of the gasket resin 65, the resin used, and the method of deforming the gasket bottom are the same as in the first embodiment. The results are shown in Table 1.

表１に示すように、ガスケットの底壁部の外側面の凹凸差は、参考例１、参考例２に比
べて実施例１のほうが明らかに小さくなっており、本発明がガスケット４に歪みを残すことなくガスケットの成型を可能にしていることがわかる。

As shown in Table 1, the unevenness difference of the outer surface of the bottom wall portion of the gasket is clearly smaller in Example 1 than in Reference Example 1 and Reference Example 2, and the present invention distorts the gasket 4. It can be seen that the gasket can be molded without leaving.

  Table 1 shows the cycle time during molding. Since the cycle time largely depends on the molding machine such as heating and cooling of the resin, the cycle time is shown as a comparative value using the same molding machine.

  Compared to the conventional molding methods of Reference Example 1 and Reference Example 2, since the drive of the mold is less, the cycle time of Example 1 which is the present invention is shortened, and the present invention is superior in terms of mass productivity. It shows that.

  Next, in the gasket molding method, the slit width W, the inclination angle A, and the edge width L were changed to verify the shape of the gasket, and the results are shown in Table 2.

（実施例２）
実施例２は、図３に示す成型金型２０であって、スリット幅Ｗを０．０７ｍｍ、傾斜角度Ａを４５度、エッジ幅Ｌを０．０３ｍｍとした。ガスケットの形状、使用した樹脂は、実施例１と同様とした。

(Example 2)
Example 2 is the molding die 20 shown in FIG. 3, wherein the slit width W is 0.07 mm, the inclination angle A is 45 degrees, and the edge width L is 0.03 mm. The shape of the gasket and the resin used were the same as in Example 1.

As a result of visual inspection and dimension measurement of this gasket, the total defect rate was 0.2% or less.
(Example 3)
Example 3 is the molding die 20 shown in FIG. 3 and has a slit width W of 0.25 mm, an inclination angle A of 80 degrees, and an edge width L of 0.10 mm. The shape of the gasket and the resin used were the same as in Example 2.

As a result of visual inspection and dimension measurement of this gasket, the total defect rate was 0.5% or less.
(Reference Example 3)
Reference Example 3 is the molding die 20 shown in FIG. 3, and the slit width W was set to 0.05 mm, and the rest was the same as Example 2.

  As a result of visual inspection and dimension measurement of the gasket, defects (sinks) in which the resin was not sufficiently filled on the side surface of the gasket occurred, and there were some gaskets with a small diameter (deformation).

This is presumably because sufficient pressure is not applied to the resin when filling the resin mold.
(Reference Example 4)
Reference Example 4 is the molding die 20 shown in FIG. 3, and the slit width W was set to 0.30 mm, and the rest was the same as Example 2.

As a result of visual inspection and dimension measurement of the gasket, many burrs (vertical burrs) in the height direction of the gasket were generated at the resin injection port 31 of the gasket. It is considered that the resin injection port 31 (slit SR) is widened and the resin is not cut well.
(Reference Example 5)
Reference Example 5 is the molding die 20 shown in FIG. 3, wherein the slit width W is 0.10 mm, the inclination angle A is 30 degrees, and the edge width L is 0.10 mm. did.

As a result of visual inspection and dimension measurement of the gasket, burrs (lateral burrs) in the radial direction of the gasket were generated. If this angle is smaller than 45 degrees, the resin is injected from the side, and the burr direction is considered to change to the horizontal direction.
(Reference Example 6)
Reference Example 6 is the molding die 20 shown in FIG. 3, and the inclination angle A is 85 degrees, and other than that is the same as Reference Example 5.

As a result of visual inspection and dimension measurement of this gasket, sink marks occurred. This is probably because the taper of the resin injection port 31 (lead-out passage P) of the resin is reduced, and a sufficient pressure is not transmitted to the resin when the resin is filled into the mold, causing sinks.
(Reference Example 7)
Reference Example 7 is a molding die 20 shown in FIG. 3, wherein the slit width W is 0.10 mm, the inclination angle A is 45 degrees, the edge width L is 0.01 mm, and the rest is the same as in Example 2. did.

As a result of visual inspection and dimension measurement of this gasket, the protrusion 32 was missing. This is considered because the stress at the time of cutting the gasket resin R was concentrated too much on the protrusion 32 of the fixed mold 21.
(Reference Example 8)
Reference Example 8 is the molding die 20 shown in FIG. 3, and the edge width L is set to 0.15 mm, and other than that is the same as Reference Example 7.

  As a result of visual inspection and measurement of the gasket, vertical burrs were generated. It can be considered that when the ridge 32 is enlarged so far, the resin to be filled becomes poor in cutting and as a result, vertical burrs are generated.

Next, effects of the present embodiment configured as described above will be described below.
(1) In the present embodiment, the molten resin flows into the gasket-shaped space GS from the position corresponding to the entire inner circumference of the bottom wall portion 13 of the annular gasket 4 in the circumferential portion of the gasket-shaped space GS. I made it. Accordingly, the gasket resin R filled in the gasket-shaped space GS is filled while applying a uniform pressure. Moreover, since the molten resin is directly injected into the gasket-shaped space GS from the resin injection port 31 formed in the annular slit, there is no conventional gate such as a disk gate or a film gate.

  (2) In this embodiment, the lead-out passage P connected to the resin injection port 31 formed in the annular slit is formed in a tapered shape toward the resin injection port 31. Therefore, when the movable mold 22 and the gate mold 23 are released from the fixed mold 21, the resin in the resin injection port 31 (lead-out passage P) remains on the spot without being drawn out. At the same time, the gasket resin R filled in the gasket-shaped space GS is separated from the resin injection port 31 formed in the annular slit.

  At this time, the lead-out passage P has a tapered shape toward the resin injection port 31 and the slit width W of the resin injection port 31 can be reduced, and the gasket resin R is cut off at the same time as the mold release. The force applied to the gasket 4 is suppressed, and the distortion of the bottom wall portion 13 of the gasket resin R can be suppressed to increase the dimensional accuracy of the gasket 4.

  (3) In the present embodiment, the resin in the resin injection port 31 can be separated from the gasket resin R simply by releasing the movable mold 22 and the gate mold 23 from the fixed mold 21. There is no need to add a mechanism for the molding machine. Therefore, it is possible to perform molding with an inexpensive injection molding machine and molding mold structure, and it is possible to shorten the cycle time of gasket manufacturing and improve productivity.

(4) In the present embodiment, the annular protrusion 32 is formed, and the thin portions that are easily separated are increased in length, so that the separation can be easily and reliably performed.
(5) In this embodiment, the slit width W of the resin inlet 31 of the annular slit is 0.07 mm to 0.25 mm, the inclination angle A is 45 degrees to 80 degrees, and the edge width L is 0.03 mm to 0.00. Since the thickness is 1 mm, it is possible to manufacture the gasket 4 with few burrs and sink marks and a low defect rate.

  (6) In this embodiment, the resin material of the gasket 4 is polyphenylene sulfide resin (PPS), polyether ether ketone resin (PEEK), liquid crystal polymer (LCP), polyether nitrile resin (PEN), polyamide resin (PA). A resin material made of at least one kind of polyimide resin (PI) was used. Accordingly, a gasket having excellent heat resistance can be manufactured, and the capacitor 1 can be assembled by reflow soldering.

In addition, you may change the said embodiment as follows.
In the above embodiment, the gasket 4 is embodied in the coin-type electric double layer capacitor 1, but may be embodied in the manufacture of other electrochemical cell gaskets such as a coin-type primary battery and a coin-type secondary battery.

In the above embodiment, the movable mold 22 and the gate mold 23 are configured separately, but this may be implemented by a movable mold in which the movable mold 22 and the gate mold 23 are integrated.
-In above-mentioned embodiment, although the protrusion 32 was formed in the fixed mold 21, you may abbreviate | omit this.

  In the above embodiment, the movable mold 22 and the gate mold 23 are movable and the fixed mold 21 is immovable. However, the movable mold 22 and the gate mold 23 are immovable and fixed. The mold 21 may be movable so as to perform mold clamping and mold release.

  In the above embodiment, the molding die 20 for molding one gasket 4 has been described. However, the molding die 20 may be applied to a multi-cavity molding die that can mold a plurality of gaskets 4 at the same time.

Sectional drawing of an electric double layer capacitor. (A) is a whole perspective view of a gasket, (b) is sectional drawing. Sectional drawing of the principal part of a shaping die. The principal part expanded sectional view of a molding die. (A) is principal part sectional drawing of the molding die for demonstrating the state at the time of resin filling, (b) is principal part sectional drawing when a molding die is released. FIG. 2A is a conventional delegate mold, in which FIG. 1A is a cross-sectional view of the main part of the mold for explaining the state of resin filling, and FIG. FIG. A conventional film gate type molding die, wherein (a) is a cross-sectional view of the main part of the molding die for explaining the state when the resin is filled, and (b) is an essential part when the molding die is released. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Coin type electric double layer capacitor (capacitor), 2 ... Positive electrode can, 3 ... Negative electrode can, 4 ... Gasket, 5 ... Positive electrode, 6 ... Separator, 7 ... Negative electrode, 8 ... Electrolyte, 11 ... Outer wall , 12 ... inner peripheral wall part, 13 ... bottom wall part, 14 ... groove part, 20 ... injection mold, 21 ... fixed mold, 22 ... movable mold, 23 ... gate mold, 31 ... resin injection port, 32 DESCRIPTION OF SYMBOLS ... Projection, 41 ... Tip part, 41a ... Small diameter part, 41b ... Reduced diameter part, 42 ... Inclined surface, A ... Inclination angle, L ... Edge width, W ... Slit width, P ... Outlet passage, R ... Gasket resin, GS: Gasket shape space, SR: Slit.

Claims (5)

After injecting molten resin into the gasket-shaped space formed by the first mold and the second mold, the first mold and the second mold are separated to form the gasket-shaped space. An annular gasket molding die for molding an annular gasket with a filled gasket resin,
The injection port for injecting the molten resin into the gasket-shaped space has the first mold and the first mold so that the molten resin is injected from a position corresponding to the entire inner circumference of the bottom of the annular gasket in the gasket-shaped space. An annular slit is formed between the second mold and an outlet passage formed by the first mold and the second mold connected to the inlet formed in the annular slit. A molding die for an annular gasket, which is formed to have a tapered shape toward an inlet. In the molding die for annular gaskets according to claim 1,
The annular gasket is a coin-type electrochemical cell gasket, wherein the annular gasket is a molding die. In the molding die for annular gaskets according to claim 1,
An annular gasket molding die, characterized in that an annular protrusion is formed to protrude toward the gasket-shaped space at the opening edge of the inlet formed in the annular slit. In the molding die for annular gaskets according to claim 3,
The slit width of the inlet formed in the annular slit is 0.07 mm to 0.25 mm, and the inclination angle of the outlet passage tapered toward the inlet formed in the annular slit is 45. A molding die for an annular gasket, characterized in that the annular projection has a width of 0.03 mm to 0.1 mm. In the molding die for annular gaskets according to any one of claims 1 to 4,
The resin to be injected into the gasket-shaped space is polyphenylene sulfide resin (PPS), polyether ether ketone resin (PEEK), liquid crystal polymer (LCP), polyether nitrile resin (PEN), polyamide resin (PA), polyimide resin (PI A molding die for an annular gasket, which is a resin material comprising at least one kind of

Images