JP2915372B2 - Liquid supply system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for, for example, sealing a component with a resin in a vacuum chamber, and is used to supply a liquid such as a resin from an injection valve in a fixed amount. It concerns the supply system.

[0002]

2. Description of the Related Art In general, when a component is molded with a resin in a vacuum chamber, a resin base material and a curing agent are supplied to mix the base material and the curing agent, and a mixture of the mixed resin is vacuumed from an injection valve. It is designed to be injected into a product set in a room in a vacuum state. The above-mentioned article is obtained by inserting an electronic component or the like into a casing or the like, for example, and injecting a resin into the casing or the like to seal the electronic component or the like.

When a mixture of a resin obtained by mixing a resin base material and a curing agent is supplied by a fixed amount and injected into an article, the main agent and the curing agent are respectively measured by separate fixed-quantity extrusion pumps and are extruded by a fixed amount. When extruding with the constant-rate extrusion pump, the injection valve is opened, the mixture of the resin mixed with the mixer between the constant-rate extrusion pump and the injection valve is injected into the product, and after performing the constant-rate extrusion, the injection valve is closed. .

[0004]

By the way, in the above-mentioned prior art, the main resin and the hardening agent of the resin are measured and supplied in a fixed amount, whereby the mixture of the resin is supplied in a fixed amount from the injection valve. However, when the injection valve is opened because the injection valve is located in the vacuum chamber, a strong vacuum is suctioned from the vacuum chamber, and this suction force acts up to the fixed-rate extrusion pump to inject the product from the injection valve. In some cases, the resin mixture may be higher or lower than the set amount, and there is a problem that it is not possible to accurately supply a fixed amount of the resin mixture. In other words, in a fixed-rate extrusion pump or a mixer, there is a movable member such as a shaft, and the movable member is rotatably and movably supported by a sealing material in order to keep the portion airtight. It is not always possible to completely maintain the airtightness (particularly, the sealing performance is deteriorated due to abrasion due to aging, etc.). When suction force from the vacuum chamber acts, air often flows from this portion, and the air that flows in When the resin is caught in the resin, a problem arises in that the amount injected from the injection valve is different for each injection because it is sucked from the vacuum chamber. In addition, when air is entrained in the resin, there is also a problem that air bubbles are included in the product or air bubbles adhere to the product, resulting in a defective product.

SUMMARY OF THE INVENTION The present invention has been made in view of the above description, and has as its object to accurately supply a fixed amount of liquid even if a liquid such as resin is supplied from an injection valve in a vacuum chamber. I do.

[0006]

In order to solve the above-mentioned problems, a liquid quantitative supply system according to the present invention is capable of pouring a liquid into an article.
The injection valve is arranged in the vacuum chamber to be filled, and the injection valve and the liquid supply source for supplying the liquid are communicated with each other through the supply pipe, and the liquid is stored in the lower part in the middle of the supply pipe and the upper part is in the space. A delivery tank is provided, and a piston-type delivery pump is provided at the bottom of the delivery tank to measure and deliver the liquid.When the injection valve is opened and the liquid is delivered by the pump, the space above the delivery tank is removed. It is characterized by being kept in a vacuum state. When an injection valve is opened when a liquid is sent out by a delivery pump unit and a fixed amount of liquid is sent out by a delivery pump unit, a fixed amount of liquid can be discharged from the injection valve and injected. Vacuum pressure is applied from the vacuum chamber when the liquid is delivered by the delivery pump unit.However, since the upper space in the delivery tank is also maintained in a vacuum state, air is not entrained in the liquid, and The suction pressure and the suction pressure from the delivery tank are balanced, and even a liquid that is supplied from an injection valve in a vacuum chamber can inject a fixed amount of liquid.

It is also preferable that the space above the delivery tank is maintained at a normal pressure when the piston of the piston type delivery pump is slid so as to be pulled out of the measuring tube. . After injecting the liquid with the sending pump part with the upper part in the sending tank in a vacuum state, close the injection valve and slide the piston part to pull out from the measuring tube part, the liquid smoothly flows into the measuring tube part Then, the next fixed quantity sending can be performed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an example in which a mixture of a resin base material and a curing agent is used as a liquid, and the mixture is injected into an article in a vacuum chamber from an injection valve and sealed. The article is obtained by inserting a component such as an ignition coil into a casing, for example, and injecting the resin into the casing and sealing the casing.

In FIG. 3, reference numeral 1 denotes a main agent storage tank for storing the main agent of the resin. The main agent heated to a predetermined temperature is supplied from the main agent supply pipe 2 by suction by evacuating the main agent storage tank 1 so that the main agent is supplied. Is stored in a predetermined amount. In the main agent storage tank 1, a stirring blade 3 for stirring the main agent is provided, and the stirring blade 3 is driven to rotate by a stirring motor 4. A vacuum pump 6 is connected to the main agent storage tank 1 via a vacuum pipe 5 so that the main agent can be degassed by vacuum suction of the main agent storage tank 1. The vacuum line 5 is provided with a trap 7 and an opening / closing valve 8. The main agent storage tank 1 is provided with a vacuum gauge 9 and a leak valve 10 for opening to the atmosphere. A main agent feed pipe 11 is led out from an outlet at the bottom of the main agent storage tank 1, and an opening / closing valve 12 is provided in the main agent feed pipe 11. In FIG. 3, reference numeral 13 denotes a hardening agent storage tank for storing the hardening agent of the resin. When the inside of the hardening agent storage tank 13 is evacuated, the hardening agent is sucked in from the hardening agent supply pipe 14 and stored therein. It has become so. The hardener storage tank 13 has basically the same structure as the main agent storage tank 1. The inside of the hardening agent storage tank 13 is provided with a stirring blade 3 for stirring the hardening agent, and the stirring blade 3 is rotated by a stirring motor 4. The hardening agent storage tank 13 is connected to a vacuum pump 6 via a vacuum pipe 5 so that the hardening agent can be degassed by vacuum suctioning the inside of the hardening agent storage tank 13. The vacuum line 5 is provided with a trap 7 and an opening / closing valve 8. The hardener storage tank 13 is provided with a vacuum gauge 9 and a leak valve 10 for opening to the atmosphere. A curing agent feed pipe 15 is led out from an outlet at the bottom of the curing agent storage tank 13,
5 is provided with an opening / closing valve 12.

FIG. 4 shows a path through which the main agent and the hardener are sent from the main agent feed pipe 11 and the hardener feed pipe 15, and the portion indicated by the symbol A in FIG. 3 and the portion indicated by the symbol A in FIG. In this case, a portion indicated by reference numeral B in FIG. 3 and a portion indicated by reference numeral B in FIG. 4 communicate with each other. As shown in FIG. 4, a main agent feed pump 16 is disposed in the main agent feed tube 11, and a hardener agent feed tube 15 is provided.
Is provided with a hardener feed pump 17. The main agent feed pump 16 and the curing agent feed pump 17 have the same structure, and have a structure as shown in FIG. Cylinder 18
Is provided with an inflow port 19 through which a main agent, a curing agent, etc. flows, and a discharge port 20 for discharging the same, and a cylinder 18 is provided with a piston 22 reciprocally driven by a piston rod 21. A check valve 23 is provided in front of the discharge port 20. 6A, when the piston 22 is advanced from the state in which the piston 22 is retracted from the measuring tube 24 and the piston 22 is inserted into the measuring tube 24, the main agent and the curing agent in the measuring tube 24 are pushed. When the check valve 23 is opened and the main agent or the hardener is discharged from the outlet 20 and the predetermined main agent or the hardener in the measuring tube 24 is pushed, the check valve 23 is closed as shown in FIG. Then, as shown in FIGS. 6D and 6E, the piston 22 retreats, and the main agent and the curing agent are supplied into the measuring tube 24. By extruding the main agent and the hardener in the measuring tube 24 from the piston 22 in this manner, the metered amount of the main agent and the hardener is discharged from the discharge port 20.
At this time, by changing the length by which the piston 22 is moved in the measuring tube 24, the amount of the main agent and the curing agent to be sent can be changed. Main agent feed pump 16 and hardener feed pump 1
The piston rod 21 is driven in synchronization with a common driving device 25. This driving device 25
Is designed to drive the piston rod 21 by converting the rotation of the servomotor into a reciprocating motion. A main agent feed pipe 27 is led out from the outlet 20 of the main agent feed pump 16, and a hardener feed tube 28 is drawn out from the outlet 20 of the hardener feed pump 17. Is connected to the mixer 29. The main resin extruded from the main agent feed pump 16 and the hardener extruded from the hardener feed pump 17 are mixed by the mixer 29 so that the mixed resin mixture is discharged from the outlet of the mixer 29. Has become. The mixer 29 is configured to rotate the stirring blades by a motor 65 to mix. The mixer 29 is provided with a heater for heating the resin mixture as required. The mixture feed pipe 30 is led out from the discharge port of the mixer 29, and the mixture of the resin is supplied from the mixer 29 to the mixture feed pipe 30.
It can be sent at.

FIG. 5 shows the path through which the mixture is sent next in the mixture feed pipe 30, and FIG.
C of the mixture feed pipe 30 is connected. The mixture feed pipe 30 is provided with a distribution section 31, and a plurality of branched mixture feed pipes 32 are led out of the distribution section 31, and the resin mixture sent from the mixture feed pipe 30 is distributed by the distribution section 31. Thus, the mixture can be sent through a plurality of mixture sending pipes 32. Each of the mixture feed pipes 32 is provided with a delivery tank 33 as shown in FIG. 1 so that the resin mixture sent from the mixture feed pipe 32 can be supplied to the delivery tank 33. Can be stored in the lower portion of the delivery tank 33. A liquid level sensor 66 is provided on the side of the delivery tank 33, and when the liquid level falls, a resin mixture is supplied into the delivery tank 33 from a supply port 67 communicating with the mixture delivery pipe 32. Thus, the liquid level of the resin mixture in the delivery tank 33 is always kept constant. A piston type delivery pump section 34 is provided below the delivery tank 33.
The delivery pump section 34 is mainly composed of a vertically long cylindrical body 35 and a piston section 37 driven up and down by a piston rod 36. A communication hole 38 for communicating the inside of the cylinder 35 with the outside of the cylinder 35 is provided at an upper portion of the cylinder 35, and a portion below the communication hole 38 of the cylinder 35 serves as a measuring tube portion 39. A portion above the communication hole 38 of the body 35 serves as a guide portion 40 of the piston portion 37.
A check valve 68 is provided below the discharge port 41 at the lower end of the measuring tube section 39. Then piston rod 3
6, the piston portion 37 can be driven up and down. However, by lowering the piston portion 37 and sliding the piston portion 37 in the measuring tube portion 39, the resin mixture is extruded and the discharge port 41 is extruded. , Can be discharged through the check valve 68 and sent out through the mixture feed pipe 42. The piston rod 36
Are driven by converting the rotation of a servomotor into a reciprocating motion. The upper part in the delivery tank 33 is a space, and the air pipe 43 is led out of the space above the delivery tank 33. This air line 43
Is connected to a vacuum pump 45 via a vacuum pipe 44, and a trap 46 and an opening / closing valve 47 are interposed in the vacuum pipe 44. When the mixture is delivered from the delivery pump section 34, the space above the delivery tank 33 is kept in a vacuum state. The air line 43 is provided with a branch line 48 separate from the vacuum line 44. The branch line 48 is provided with a leak valve 49, an atmosphere release valve 50 and a vacuum gauge 51 in parallel. When the piston portion 37 is pulled out of the measuring tube portion 39 after the resin mixture has been sent out from the delivery pump portion 34, the space above the delivery tank 33 is opened to the atmosphere to be at normal pressure. In FIG. 1, 58 is a viewing window for looking into the internal state, 69 is a heater, and 70 is a heat insulating material.

A vacuum cooker 54 is disposed in the injection molding apparatus. A table 53 is disposed below the vacuum cooker 54 so as to be movable up and down. Is closed by a table 53 to form a vacuum chamber inside. That is, the vacuum cooker 54 has an opening at the lower surface, and the opening at the lower surface is closed by the table 53 serving as a lid to form a vacuum chamber. On the table 53, a pallet on which a plurality of items are set is placed.
The pallet on which the articles are placed can be set in the vacuum chamber by placing the pallet at a position below the pallet and raising the table 53. The article placed on the pallet is, for example, one in which a component such as an ignition coil is inserted into a casing, and a plurality of articles are set on the pallet at equal intervals. The vacuum pot 54 is provided with an injection valve 55 for each of a plurality of articles. Injection valve 5
Reference numeral 5 has a nozzle for injecting a resin mixture into an article, and has a structure which is opened and closed by a needle valve. The mixture feed pipes 42 for sending the resin mixture sent from the delivery pump section 34 are respectively connected to the injection valves 55. A vacuum pump 57 is connected to the vacuum cooker 54 via a vacuum pipe 56, and an open / close valve 59 is provided in the vacuum pipe 56. When the table 53 is in contact with the lower surface of the vacuum cooker 54 to form a vacuum chamber, the vacuum is suctioned from the vacuum pipe 56 to maintain the vacuum state of the vacuum chamber. An atmosphere opening valve 61 is connected to the vacuum cooker 54 through an atmosphere opening pipe 60.
The vacuum chamber can be opened to the atmosphere by opening the atmosphere release valve 61. The vacuum cooker 54 is provided with a leak valve 63 via a leak pipe 62, and the degree of vacuum in the vacuum chamber can be adjusted by leaking at the leak valve 63.

Next, the overall operation of injecting a mixture of a resin obtained by mixing a resin base material and a curing agent in a fixed amount from the injection valve 55 will be described. The main agent storage tank 1 stores the main agent of the resin, and the hardened material storage tank 13 stores the hardener of the resin. The main agent feed pump 16 and the hardener feed pump 17 are driven to drive the main agent feed pipe. The main agent and the hardener are sent to the main agent feed pump 16 and the hardener feed pump 17 via 11 and the hardener feed pipe 15. By driving the main agent feed pump 16 and the hardener feed pump 17, the main agent and the hardener are measured via the main agent feed pipe 27 and the hardener feed pipe 28, and a predetermined amount of the mixture is supplied to the mixer 29.
And the mixing of the main agent and the curing agent by the mixer 29 to form a resin mixture. The mixture of the resins mixed by the mixer 29 is supplied to a delivery tank 33 through a mixture delivery pipe 30. Delivery tank 33
Is fed to the injection valve 55 via the mixture feed pipe 42 by the delivery pump section 34,
From the injection valve 55, a fixed amount of the resin mixture is injected into the article in the vacuum chamber.

When the resin mixture is injected from the injection valve 55, a table 53 is in contact with the lower surface of the vacuum pot 54 to form a vacuum chamber, and a predetermined vacuum state is established by vacuum suction in the vacuum chamber. It can be injected while keeping it. When injecting a fixed amount of the resin mixture from the injection valve 55, open the injection valve 55,
The resin mixture in the measuring tube section 39 is extruded by lowering the piston section 37 of the delivery pump section 34. At this time, the space above the delivery tank 33 is maintained in a predetermined vacuum state. At this time, by controlling the vacuum suction from the vacuum pump 45 and the leak from the leak valve 49, the vacuum state in the space above the delivery tank 33 is set to a predetermined vacuum state. When the space above the delivery tank 33 is evacuated in this way, even if the injection valve 55 is opened and vacuum is drawn from the vacuum chamber, no air is entrained in the resin mixture, and the vacuum chamber is The balance between the suction pressure and the suction pressure from the delivery tank 33 can be balanced, and the resin mixture can be injected from the injection valve 55 by a predetermined amount to extrude the resin mixture in the measuring tube section 39 by the piston section 37. . When the resin mixture is delivered from the delivery tank 33, the piston portion 37 is stationary at a position where the lower end of the piston portion 37 and the upper end of the measuring tube portion 39 correspond to each other. The portion 37 is driven downward to extrude the resin mixture by the piston portion 37 and discharged from the injection valve 55, and only the fixed amount of the resin mixture extruded by the piston portion 37 is injected from the injection valve 55. At this time, the amount to be measured can be changed by changing the length of movement of the piston portion 37. The degree of vacuum in which the space above the delivery tank 33 is evacuated may be a predetermined degree of vacuum or higher, and may be lower than the degree of vacuum in the vacuum chamber. Of course, the delivery tank 33
It is most preferable that the degree of vacuum in the space above and the degree of vacuum in the vacuum chamber be the same. When the resin mixture is injected into the product from the injection valve 55, air bubbles are not included in the product because the resin mixture does not contain air. After the fixed amount of the resin mixture is injected from the injection valve 55, the injection valve 55 is closed, and the piston 37 is driven so as to be pulled out of the measuring tube 39. At this time, the atmosphere release valve 50 is opened,
The space above the delivery tank 33 is at normal pressure. By setting the space above the delivery tank 33 to normal pressure in this manner, when the piston portion 37 is pulled out of the measuring tube portion 39, the resin mixture smoothly flows into the measuring tube portion 39 from the communication hole 38. Prepare for the next extrusion.
Immediately after the piston portion 37 is removed from the measuring tube portion 39 and the resin mixture is filled in the measuring tube portion 39, the space above the delivery tank 33 is evacuated.

[0015] In the above example, 2 is composed of the main agent and the curing agent.
Although an example in which a liquid-curable resin is supplied in a fixed amount has been described, the present invention is not limited thereto, and a one-liquid curable resin or a light-curable resin may be used. Other liquids may be used. In short, any liquid can be supplied quantitatively.

[0016]

As described above, the present invention injects a liquid into an article.
The injection valve is arranged in the vacuum chamber to be connected and the injection valve and the liquid supply source for supplying the liquid are communicated through the supply pipe,
A supply tank is provided in the lower part of the supply pipe in which liquid is stored at the lower part and the upper part is a space, and a piston type pump part for measuring and sending the liquid at the lower part of the supply tank is provided. since to keep a vacuum state an upper space of the tank for feeding when feeding in the open pump unit feed liquid, a vacuum chamber
Open the inlet valve when the feeding liquid pump unit delivery in order to inject the liquid into the goods, the feeding was weighed quantified feed pump liquid from the injection valve as it can be injected by ejecting Determination of liquid Of course, there is a vacuum pressure from the vacuum chamber when sending out the liquid with the delivery pump part, but since the upper space in the delivery tank is also kept in a vacuum state, air is not caught in the liquid, In addition, the pressure of suction from the vacuum chamber and the pressure of suction from the delivery tank can be balanced, and even if liquid is supplied from the injection valve of the vacuum chamber, a certain amount of liquid can be injected. Since the air is not entrained in the liquid, there is no danger that the injected liquid contains bubbles or adheres to the bubbles.

According to a second aspect of the present invention, when the piston portion of the piston type delivery pump is slid so as to be pulled out of the measuring tube portion, the space above the delivery tank is maintained at normal pressure. Since the upper part of the delivery tank is evacuated and the liquid is injected by the delivery pump, the injection valve is closed and the piston is slid so that the piston is removed from the measurement tube. The next time, a fixed amount of liquid can be sent by injecting the liquid.

[Brief description of the drawings]

FIG. 1 is a sectional view of a delivery tank portion, which is a main part of a quantitative supply system according to the present invention.

FIG. 2 is a partially cut-away schematic front view of an injection molding apparatus using the above quantitative supply system.

FIG. 3 is a piping diagram of an upstream portion of a supply line of the quantitative supply system according to the first embodiment.

FIG. 4 is a piping diagram of an intermediate portion of a supply pipe of the quantitative supply system according to the first embodiment.

FIG. 5 is a piping diagram of a downstream portion of a supply pipe of the fixed quantity supply system.

FIGS. 6 (a), (b), (c), (d), and (e) are cross-sectional views showing the structure and operation of a main agent feed pump and a curing agent feed pump according to the first embodiment.

[Explanation of symbols]

 33 Delivery tank 34 Delivery pump section 35 Piston section 39 Measuring tube section 54 Vacuum pot 55 Injection tube

Claims (2)

(57) [Claims] An injection valve is disposed in a vacuum chamber for injecting a liquid into an article, and the injection valve is connected to a liquid supply source for supplying the liquid through a supply line. Is provided and a delivery tank is provided in which the upper part becomes a space, a piston type delivery pump part for measuring and sending the liquid is provided at the lower part of the delivery tank, the injection valve is opened and the liquid is sent out by the pump part. A fixed-quantity liquid supply system characterized in that the space above the delivery tank is maintained in a vacuum state. 2. The method according to claim 1, wherein the space above the delivery tank is maintained at normal pressure when the piston of the piston type delivery pump is slid so as to be pulled out of the measuring tube. 2. The liquid quantitative supply system according to 1.