JPH0586063B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method and apparatus for vacuum impregnation of an electrolytic capacitor element with an electrolytic solution, and in particular to a vacuum impregnation method and apparatus for vacuum impregnation of an electrolytic solution in an electrolytic capacitor element. By keeping the temperature lower than in the vacuum impregnation tank and drawing a vacuum, the pressure difference is smaller than when directly supplied from atmospheric pressure, and boiling of the electrolyte supplied to the vacuum impregnation tank is suppressed. The present invention relates to a method and apparatus for vacuum impregnating an electrolytic capacitor element with an electrolytic solution, which prevents the electrolytic solution from adhering to the lead wires of the electrolytic capacitor element and suppresses the generation of bubbles.

Conventional technology Conventionally, an electrolytic capacitor element whose lead wires are attached at predetermined intervals using continuous adhesive tape and which has been taped is conveyed into a vacuum impregnation tank, and the inside of the vacuum impregnation tank is brought into a vacuum state. A method and an apparatus have been proposed and put into practical use in which air is removed from inside the body of an electrolytic capacitor element, and then an electrolytic solution is supplied to impregnate the inside of the body of the element.

For example, the process of impregnating the electrolyte 18 into the electrolytic capacitor element 8 by the conventional electrolyte vacuum impregnation device 71 shown in FIG.
9, 29, 30, 37 and the air valve 43 are closed, and the air valve 47 is opened and the vacuum pump 39
rotates, vacuuming of the vacuum impregnation tank 3 is started,
The vacuum impregnation tank is evacuated as shown by arrow A.

Air from the vacuum impregnation tank 3 enters the air filter 41 through the hose 42, and then through the hose 38 as shown by arrow B to the suction port 39a of the vacuum pump 39.
to go into. When the vacuum detection sensor 46 detects that the inside of the vacuum impregnation tank 3 has reached a degree of vacuum of approximately 20 torr after such evacuation is carried out for a certain period of time, the air valve 47 closes and the vacuum pump 39 is activated. stops.

At the same time, when the valve 30 opens and the magnetic pump 31 rotates, atmospheric pressure (760 torr) is acting on the electrolyte tank 28, so the electrolyte 18 in the electrolyte tank flows through the hose 50 as shown by arrow C.
and flows into the vacuum impregnation tank 3 from the electrolyte supply port 24 through the valve 30 along with air bubbles. Referring also to FIG. 5, when the liquid level 18a of the electrolytic solution 18 reaches slightly above the element body 8c, this is detected by the liquid level detection device 51, and the valve 30 of the electrolytic solution supply port 24 is closed. , the supply of the electrolytic solution 18 is stopped, and the electrolytic solution 18 in the vacuum impregnating tank 3 is impregnated into the element body 8c of the electrolytic capacitor element 8 in a few seconds.

At this time, as shown in Fig. 6, the electrolyte is supplied from the electrolyte tank 28 under atmospheric pressure (760 torr) into the vacuum impregnation tank 3, which is evacuated to a vacuum level of about 20 torr. Since the electrolytic solution 18 contains air bubbles, the air bubbles expand and burst due to a very large change in pressure, as shown in FIG. There was a drawback in that the ripples caused the lead wires 8a of the electrolytic capacitor element 8 and the adhesive tape 5 to become dirty.

Recently, electrolytes with a viscosity as low as that of water, or conversely a very high viscosity, have come to be used, and the pressure inside the vacuum impregnation tank has been lowered to a much higher degree of vacuum. The electrolytic solution boils violently in the vacuum impregnation tank, splashing around various parts, and adhering to the lead wires, causing poor soldering and reducing the operating rate of automatic assembly machines. Furthermore, the impregnation efficiency of the electrolytic solution 18 was reduced due to the presence of air bubbles.

Purpose The present invention has been made to eliminate the drawbacks of the prior art described above, and its purpose is to transport an electrolytic capacitor element not impregnated with electrolyte into a vacuum impregnation tank and seal it. The interior of the vacuum impregnation tank is kept in a vacuum state, and the electrolyte solution stored in the evacuated liquid reserve tank is kept at a vacuum level lower than the vacuum level inside the vacuum impregnation tank, and the electrolyte solution that has been depressurized one step and from which air bubbles have been removed is evacuated. By injecting the electrolyte into the impregnation tank, the boiling phenomenon of the electrolyte and the inclusion of bubbles due to large changes in atmospheric pressure are suppressed, improving the impregnation efficiency of the electrolyte. The purpose of the present invention is to completely prevent the adhesive tape from adhering to the adhesive tape, thereby making it possible to use the adhesive tape repeatedly, and to maintain the automatic electrolytic capacitor assembly machine in a clean state.

Another purpose is to easily adjust the vacuum level of the liquid reserve tank according to the vacuum level in the vacuum impregnation tank by installing dedicated sub-vacuum pumps that are connected to the vacuum impregnation tank and the liquid reserve tank, respectively. The purpose is to make it possible to adjust the temperature of the electrolyte, and thereby to make it possible to impregnate an electrolytic capacitor element without causing much of a problem with the boiling phenomenon of the electrolytic solution.

Another purpose is to improve the impregnation performance of the electrolytic solution itself by impregnating an electrolytic capacitor element in a vacuum impregnation bath adjusted to a sufficiently high degree of vacuum.

Structure In short, the method of the present invention (claim 1) involves transporting an electrolytic capacitor element not impregnated with an electrolytic solution into a vacuum impregnation tank to bring the inside of the vacuum impregnation tank into a vacuum state, and then transferring an electrolytic capacitor element not impregnated with an electrolytic solution to the vacuum impregnation tank. From the liquid reserve tank, which is evacuated while maintaining the vacuum degree in the reserve tank lower than the vacuum degree in the vacuum impregnation tank, to the vacuum impregnation tank,
The present invention is characterized in that the electrolyte is supplied with a smaller pressure difference than when supplied from atmospheric pressure, and the element body of the electrolytic capacitor element is impregnated with the electrolyte.

The device of the present invention (Claim 2) also includes a vacuum impregnation tank that accommodates electrolytic capacitor elements not impregnated with electrolyte and is evacuated by a vacuum pump, and a vacuum impregnation tank that is connected in communication with the vacuum impregnation tank to temporarily store the electrolyte. The apparatus is characterized by comprising a liquid reserve tank which is evacuated to maintain a degree of vacuum lower than the degree of vacuum of the vacuum impregnation tank.

The present invention will be explained below based on embodiments shown in the drawings. In FIG. 1, an electrolyte vacuum impregnation apparatus 1 for an electrolytic capacitor element according to the present invention includes a vacuum impregnation tank 3.
, a liquid reserve tank 2 , and a sub-vacuum pump 4 .

The vacuum impregnation tank 3 is composed of a fixed side vacuum impregnation tank 3F and a movable side vacuum impregnation tank 3M. The vacuum impregnation tank 3, which is housed in an impregnation tank 3F and sealed by bringing the joint surface 3g of the movable vacuum impregnation tank 3M into contact with the joint surface 3f of the fixed vacuum impregnation tank, is evacuated, and the electrolyte is contained therein. 18 is supplied so that the electrolytic solution is impregnated into the electrolytic capacitor element 8,
Manufactured from high quality aluminum alloy castings and other materials.

An electrolyte overflow port 21 and an electrolyte recovery port 23 are provided on the front surface 3d of the fixed side vacuum impregnation tank 3F.
and an electrolyte supply port 24 are formed to communicate with the front surface 3d. The electrolyte overflow port 21 is connected to the suction port 3 of a diaphragm pump 32 for electrolyte recovery via the hose 20 and the hose 27.
2a, and a discharge port 32b of the diaphragm pump 32 is connected to the electrolyte tank 28 through a hose 36. One end 36a of the hose 36 is connected to a port 34 attached to the upper part 28a of the electrolyte tank 28, so that the recovered electrolyte 18 drips onto the liquid surface 18b as indicated by arrow Y. The electrolyte recovery port 23 is connected via a hose 25 to a port 35 formed to communicate with the recovery tank 16 . The electrolyte supply port 24 is connected via a hose 52 to a port 9 formed to communicate with the liquid reserve tank 2 .

The electrolyte overflow port 21, the electrolyte recovery port 23, and the electrolyte supply port 24 are provided with valves 37, 29, and 30 for opening and closing these ports.
are attached to each of them, and these are controlled by a control device (not shown).

An electrolyte recovery port 22 is formed on the front surface 3e of the movable vacuum impregnation tank 3M so as to communicate with the front surface 3e. The electrolyte recovery port 22 is a port 4 formed in communication with the recovery tank 16 via the hose 17.
5 is connected in communication.

Port 2 formed in communication with recovery tank 16
6 is a diaphragm pump 32 via a hose 27
The suction port 32a is connected to the suction port 32a. A valve 70 for opening and closing the port is attached to the port 26, and is controlled by a control device (not shown). Further, a release port 44, a vacuum air port 48, and a port 49 are formed on the upper surface 3a of the movable vacuum impregnating tank 3M so as to communicate with the upper surface 3a. Vacuum air port 4
8 is connected to an air filter 41 through a hose 42, and the air filter is connected through a hose 38 to a suction port 39a of a vacuum pump 39. The port 49 is connected via a hose 53 to a vacuum detection sensor 46 that monitors the degree of vacuum within the vacuum impregnation tank 3.

The electrolyte recovery port 22, the release port 44, and the vacuum air port 48 are equipped with a valve 19 and air valves 43 and 47, respectively, for opening and closing these ports, and these are controlled by a control device (not shown). It's summery.

There is an electrolyte port 1 in the upper part 2a of the liquid reserve tank 2.
0 and air ports 11 and 13 are formed in communication with the upper part 2a, and an electrolytic solution 18 is supplied to the electrolytic solution port 10 via the path shown below. That is, the electrolyte port 12 formed in communication with the lower part 28b of the electrolyte tank 28
is connected to the suction port 31a of the magnetic pump 31 through a hose 57, the discharge port 31b is connected to the suction port 7a of the liquid return valve 7 through a hose 56, and the supply port 7b is connected to the suction port 7a of the liquid return valve 7 through a hose 56. Liquid injection valve 6 via 55
The discharge port 6b is connected to the electrolyte port 10 via a hose 54.
This allows the electrolyte port 10 to secure a flow path communicating with the electrolyte port 12 formed in communication with the lower portion 28b of the electrolyte tank 28.

The liquid return valve 7 is configured to switch the flow path of the electrolyte 18 sent into the suction port 7a to the supply port 7b or the return port 7c under the control of a control device (not shown), and is connected to the return port 7c. One end 5 of the hose 58
8a is the liquid level 1 of the electrolyte 18 in the electrolyte tank 28
It opens facing above 8b.

The air port 11 is connected via a hose 59 to a suction port 33a of an electrolyte separation tank 33 that separates air and the electrolyte 18. Further, the air port 11 is equipped with an air valve 14 for opening and closing the air port, and is controlled by a control device (not shown).

The air port 13 is connected to a vacuum detection switch 15 via a hose 67, and a command to operate the air valve 14 is issued by the vacuum detection switch.

A port 9 and a liquid level detection device 61 are connected to the lower part 2b of the liquid reserve tank 2 so as to communicate with the lower part 2b. An electrolytic solution 18 is supplied into the impregnation tank 3.

The liquid level detection device 61 is composed of a liquid column pipe 62 that measures the water level of the electrolytic solution 18 in the liquid reserve tank 2, and a pair of photo sensor units 63 and 64. The water level is detected, and the photo sensor unit 64 detects the lowest liquid level and sends a signal to a control device (not shown).

The air discharge port 33b of the liquid separation tank 33 is connected to the suction port 4 of the sub-vacuum pump 4 via a hose 60.
It is communicatively connected to a. The electrolyte discharge port 33c of the electrolyte separation tank 33 is connected to a drain tank 66 via a hose 65.

Air discharge port 33b and electrolyte discharge port 3
3c is equipped with an air valve 68 and a valve 69 for opening and closing these ports, respectively, and these are controlled by a control device (not shown).

The method of the present invention (claim 1) transports the unimpregnated electrolytic capacitor element 8 into the vacuum impregnation tank 3F to bring the inside of the vacuum impregnation tank 3 into a vacuum state, and prepares a liquid reserve connected to the vacuum impregnation tank. The vacuum level in the tank 2 is kept lower than the vacuum level in the vacuum impregnation tank 3, and the electrolyte is transferred from the evacuated liquid reserve tank to the vacuum impregnation tank 3 with a smaller pressure difference than when it is supplied from atmospheric pressure. 18 is supplied to impregnate the element body 8c of the electrolytic capacitor element 8 with the electrolytic solution 18.

Effects The present invention is configured as described above, and its effects will be explained below. As shown in FIG. 1, the unimpregnated electrolytic capacitor element 8, whose upper ends 8b of lead wires 8a are bonded at predetermined intervals with continuous adhesive tape 5 and has been taped, is transferred to a conveyor (not shown) as shown in FIG. and reaches the fixed side vacuum impregnation tank 3F.

At this time, the movable side vacuum impregnation tank 3M is pushed out in the direction of the fixed side vacuum impregnation tank 3F by the operation of an air cylinder (not shown), etc., and the joint surfaces 3f and 3g are brought into contact with each other, so that the vacuum impregnation tank 3M is in a sealed state. This completes the preparation for vacuum impregnation of the electrolytic solution 18 into the electrolytic capacitor element 8.

Next, the electrolytic solution 1 for the electrolytic capacitor element 8 is
The impregnation step No. 8 will be explained. Valve 19,2
9, 30, 37 and the air valve 43 are closed,
The air valve 47 is opened, the vacuum pump 39 is rotated, and the vacuum impregnation tank 3 is started to be evacuated, and the vacuum impregnation tank is evacuated as shown by arrow A.

Air from the vacuum impregnation tank 3 enters the air filter 41 through the hose 42, and then through the hose 38 as shown by arrow B to the suction port 39a of the vacuum pump 39.
to go into. When the vacuum detection sensor 46 detects that the inside of the vacuum impregnation tank 3 has reached a degree of vacuum of approximately 20 torr after such evacuation is carried out for a certain period of time, the air valve 47 closes and the vacuum pump is turned off. 39 stops.

At this time, the valve 30 is opened, and the electrolytic solution 18 in the liquid reserve tank 2, which has been evacuated to a vacuum level of about 200 Torr, is degassed under vacuum, and the electrolytic solution is discharged from the port 9 through the hose 52 as shown by arrow D. and flows into the vacuum impregnation tank 3 from the electrolyte supply port 24. Referring also to FIG. 2, when the liquid level 18a of the electrolytic solution 18 reaches slightly above the element body 8c, this is detected by the liquid level detection device 51, and the valve 30 of the electrolytic solution supply port 24 is activated. close,
The supply of the electrolytic solution 18 is stopped, and the electrolytic solution 18 in the vacuum impregnating tank 3 is impregnated into the element body 8c of the electrolytic capacitor element 8 in a few seconds.

Also, at this time, as shown in Figure 3, the degree of vacuum is approximately
The electrolytic solution 18 supplied from the liquid reserve tank 2 evacuated to 200 Torr into the vacuum impregnation tank 3 evacuated to a vacuum degree of about 20 Torr has little change in atmospheric pressure and does not contain air bubbles. As shown in FIG. 2, the liquid level 18a is silently impregnated into the element body 8c of the electrolytic capacitor element 8 without any waving phenomenon, and the lead wire 8a is not only kept in a clean state but also free of air bubbles. The impregnation efficiency of the electrolytic solution 18 is high.

When impregnation with the electrolytic solution 18 is completed in the vacuum impregnation tank 3, as shown in FIG. 1, the air valve 43 is first opened to release the inside of the vacuum impregnation tank 3 to atmospheric pressure, and the pressure is increased.

Then, a little later, the valves 19 and 29 are opened, and the electrolytic solution 18 flows into the recovery tank 16 through the hose 17 as shown by arrow E and through the hose 25 as shown by arrow F.

After a while, the valves 37 and 70 are opened and the diaphragm pump 32 is activated. Overflow of the electrolyte 18 in the vacuum impregnation tank 3 is indicated by arrows G and H.
It enters the suction port 32a through the hose 20 and the hose 27 as shown in FIG. Further, the electrolyte 18 in the recovery tank 16 is passed from the port 26 to the hose 27 as shown by arrow H.
and enters the suction port 32a. The electrolyte 18 sucked by the diaphragm pump 32 is sent from the discharge port 32b through the hose 36 as shown by arrow I to the port 34, and is returned from the port into the electrolyte tank 28 as shown by arrow Y.

As a result, electrolytic capacitor element 8 is impregnated with a sufficient amount of electrolytic solution 18, and a series of electrolytic solution impregnation steps is completed.

Then, due to the opposite effect to the above, the movable vacuum impregnating tank 3M moves in the direction of retreating from the fixed vacuum impregnating tank 3F, thereby opening the bonding surfaces 3f and 3g and removing the electrolytic material adhered to the continuous adhesive tape 5. Capacitor element 8 is released. The unimpregnated electrolytic capacitor element 8 is again transported by a transport device (not shown) until it reaches the fixed vacuum impregnation tank 3F.

Here, the function of maintaining the degree of vacuum in the liquid reserve tank 2 at approximately 200 Torr will be explained. The degree of vacuum in the liquid reserve tank 2 is set by the vacuum detection switch 15 to approx.
When it is sensed that the temperature is lower than 200 Torr, the air valves 14 and 68 are opened, the sub-vacuum pump 4 is rotated, and the vacuum in the liquid reserve tank 2 is started to remove air bubbles in the electrolyte 18. The mixture of air and electrolyte 18 enters the suction port 33a of the electrolyte separation tank 33 from the liquid reserve tank 2 through the hose 59 as indicated by arrow J. The air separated in the electrolyte separation tank enters the suction port 4a of the sub-vacuum pump 4 through the hose 60 as indicated by arrow K. When the electrolyte 18 separated in the liquid separation tank 33 reaches a predetermined amount, the valve 69 is opened and the electrolyte 18 is collected from the electrolyte discharge port 33c through the hose 65 as indicated by arrow L into the drain tank 66.

When the degree of vacuum in the liquid reserve tank 2 reaches a state higher than approximately 200 Torr due to evacuation by the sub-vacuum pump 4, the vacuum detection switch 15 is reset, the air valves 14 and 68 are closed, and a predetermined degree of vacuum is maintained. Then, the sub vacuum pump 4 is stopped.

When the liquid level of the electrolytic solution 18 in the liquid reserve tank 2 falls and the liquid level is detected by the photosensor unit 64, the liquid injection valve 6 and the liquid return valve 7 are opened, and the magnetic pump 31 is opened.
starts. The electrolyte 18 in the electrolyte tank 28 enters the suction port 31a of the magnetic pump 31 through the hose 57 as shown by arrow M, and then enters the discharge port 3.
The electrolytic solution 18 discharged from 1b passes through the hose 56 as shown by the arrow N, and then from the suction port 7a whose flow path is opened by the liquid return valve 7, passes through the supply port 7b and flows through the hose 55 as shown by the arrow P. and enters the suction port 6a. Since the liquid injection valve 6 is open, the electrolytic liquid 18 passes through the hose 54 from the discharge port 6b to the electrolytic liquid port 1 as indicated by the arrow Q.
0 to the liquid reserve tank 2. When the electrolytic solution 18 is continuously supplied to the liquid reserve tank and the liquid level rises and is detected by the photosensor unit 63, the liquid injection valve 6 and the liquid return valve 7 are closed.

When the liquid return valve 7 closes, the flow path communicates from the suction port 7a to the return port 7c, so that the electrolyte 18 that has entered the suction port 7a through the hose 56 flows from the return port 7c to the hose 58 as indicated by arrow R. The electrolyte is collected through the electrolyte tank 28.

After a while, the magnet pump 31 is stopped by the action of a control device (not shown).

As described above, in the present invention, the steps of carrying the electrolytic capacitor element 8 into the vacuum impregnation tank 3, vacuum impregnation, and carrying it out from the vacuum impregnation tank 3 are automatically repeated. The electrolytic capacitor element 8 is automatically impregnated with the electrolytic solution 18 under vacuum, and a clean impregnated electrolytic capacitor element 8 in which the electrolytic solution 18 does not adhere to the lead wires 8a can be obtained. It goes without saying that the present invention is applicable not only to the taping method but also to the impregnation of electrolytic capacitor elements aligned and clamped by a clamp jig.

Effects As described above, the present invention transports an electrolytic capacitor element not impregnated with an electrolyte into a vacuum impregnation tank, sets the sealed vacuum impregnation tank to a vacuum state, and lowers the degree of vacuum than the vacuum level in the vacuum impregnation tank. The electrolyte is stored in a evacuated reserve tank that is maintained at a vacuum level, and the pressure is reduced one step to remove bubbles before it is injected into the vacuum impregnation tank, which prevents boiling of the electrolyte due to changes in atmospheric pressure. It is possible to improve the impregnation efficiency of the electrolytic solution by suppressing the inclusion of air bubbles and completely prevent the electrolyte from adhering to lead wires, adhesive tapes, etc., and as a result, the adhesive tape can be used repeatedly. This also has the effect of keeping the electrolytic capacitor automatic assembly machine in a clean state. In addition, since we have installed dedicated sub-vacuum pumps that are connected to the vacuum impregnation tank and the liquid reserve tank, the vacuum level of the liquid reserve tank can be easily adjusted according to the vacuum level in the vacuum impregnation tank. As a result, it is possible to impregnate an electrolytic capacitor element without causing much of a problem with the boiling phenomenon of the electrolytic solution. Further, by impregnating the electrolytic capacitor element in a vacuum impregnation bath adjusted to a sufficiently high degree of vacuum, it is possible to further improve the impregnation performance of the electrolytic solution.

[Brief explanation of the drawing]

1 to 3 relate to embodiments of the present invention, and FIG. 1 shows a vacuum pump, a vacuum impregnation tank, a liquid reserve tank,
An overall perspective view of the electrolyte vacuum impregnation device in relation to the sub-vacuum pump, electrolyte separation tank, and electrolyte tank. Figure 2 is a partial front view showing the state of the electrolytic capacitor element and electrolyte impregnated in the vacuum impregnation tank. Figure 3 is a diagram showing the relationship between the location of the electrolyte and the degree of vacuum, Figures 4 to 6 relate to the conventional example, and Figure 4 shows the relationship between the vacuum pump, vacuum impregnation tank, and electrolyte tank. Whole perspective view of related electrolyte vacuum impregnation device, No. 5
The figure is a partial sectional view showing the state of the electrolytic solution and the electrolytic capacitor element impregnated in the vacuum impregnating tank, and FIG. 6 is a diagram showing the relationship between the location of the electrolytic solution and the degree of vacuum. 1 is an electrolyte vacuum impregnation device for an electrolytic capacitor element, 2 is a liquid reserve tank, 3 is a vacuum impregnation tank, 4 is a sub-vacuum pump, 8 is an electrolytic capacitor element, 18 is an electrolyte, and 39 is a vacuum pump.

Claims (1)

[Claims] 1. An electrolytic capacitor element not impregnated with an electrolytic solution is transported into a vacuum impregnation tank, the vacuum impregnation tank is brought into a vacuum state, and the degree of vacuum in a liquid reserve tank connected to the vacuum impregnation tank is determined. The electrolytic solution is supplied from the evacuated liquid reserve tank to the vacuum impregnation tank with a pressure difference smaller than that when supplied from atmospheric pressure by keeping the vacuum level lower than the vacuum level in the vacuum impregnation tank. A method for vacuum impregnating an electrolytic capacitor element with an electrolytic solution, the method comprising impregnating the main body of the capacitor element with the electrolytic solution. 2. A vacuum impregnation tank that accommodates electrolytic capacitor elements not impregnated with electrolyte and is evacuated by a vacuum pump; and a vacuum impregnation tank that is connected in communication with the vacuum impregnation tank and is configured to temporarily store the electrolyte. 1. An electrolyte vacuum impregnation device for an electrolytic capacitor element, comprising: a liquid reserve tank that is evacuated to maintain a vacuum level lower than that of the electrolytic capacitor element. 3. A sub-vacuum pump is connected in communication with the liquid reserve tank, and the sub-vacuum pump separates the mixture of air and electrolyte sucked from the liquid reserve tank into air and electrolyte through an electrolyte separation tank. The electrolyte vacuum impregnation apparatus for an electrolytic capacitor element according to claim 2, characterized in that the interior of the liquid reserve tank is configured to be evacuated.