JPH0657334B2 - Liquid circulation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for circulating a liquid by a pump using air as a drive source, and more particularly to a liquid circulation apparatus for circulating a liquid by alternate operation of two pumps.

(Prior Art) This type of liquid circulation device is useful when a viscous liquid such as paint is circulated.

FIG. 5 and FIG. 6 show a conventional example when this liquid circulation device is applied to coating equipment. In these drawings, 1a and 1b are pumps using air as a driving source, and diaphragm pumps 3a and 3b driven by motors 2a and 2b are provided in the pumps 1a and 1b, respectively, and air supply pipes 4a and 4b and exhaust pipes. They are connected via pipes 5a and 5b. Valves 6a and 6b and valves 7a and 7b are provided in the air supply pipes 4a and 4b and the exhaust pipes 5a and 5b, respectively, and the pumps 1a and 1b are switched to the air supply side and the exhaust side by switching these valves. It is possible to communicate with the side alternately.

Each of the pumps 1a and 1b has a casing 9 containing a paint 8.
A discharge port 10 connected to a main tank (depping tank) A at the bottom of the tank and an overflow tank C at the main tank A.
And a suction port 11 connected to the sub-tank B connected via the discharge port 1 and the discharge port 1 at the inner bottom of the casing 9.
It has a structure in which a valve device 12 for opening and closing 0 and a butterfly valve 13 for opening and closing the suction port 11 are incorporated.

The valve device 12 includes, in particular, an outer pipe 14 connected to the discharge port 10, an inner pipe 15 which is fitted to the outer pipe 14 and communicates with the casing 9 through a liquid passage port 15 ′, and an upper opening of the inner pipe 15. It consists of a ball 16 seated on the. As a result, when the pump 1a (1b) is now connected to the air supply side,
Internal pressure is generated in the paint 8 by being pressed by the air, and as a result, the butterfly valve 13 is closed and the paint 8 flows into the inner pipe 15 through the liquid passage port 15 'and pushes up the ball 16 to raise the inner pipe 1
The gas reaches the discharge port 10 through the gap between the outer pipe 5 and the outer pipe 14, and is discharged from the discharge port 10 toward the main tank A. On the other hand, when the casing 9 is communicated with the exhaust side, the internal pressure of the paint 8 in the casing 9 is reduced and the ball 16 is closed. On the other hand, the pressure on the sub tank B side opens the butterfly valve 13 to open the paint in the sub tank B. Flows into the casing 9 through the suction port 11.

That is, the pumps 1a and 1b are operated by switching the valves 6a and 7a and the valves 6b and 7b, and the paint 8 circulates between the pump and the tank side. It should be noted that the pumps 1a and 1b are controlled to operate alternately by providing a time difference between the switching of the valves 6a and 7a and the valves 6b and 7b.

(Problems to be Solved by the Invention) However, according to the above-mentioned conventional liquid circulation device, the blowers 3a and 3b are individually provided for the pumps 1a and 1b, and the air switching valves 6a and 7a and 6b are provided. And 7
Since b must be provided individually, there is a problem that the structure becomes complicated and large, and the equipment cost and installation space increase, and maintainability deteriorates.

In addition, since the valves must be changed frequently (about 20 times per minute), the valves are heavily worn and must be replaced frequently. In some cases, a failure may occur during operation, resulting in production. There was a problem of inviting a stop.

In addition, a time lag is likely to occur when switching the valves, and smooth air supply may not be possible.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a liquid circulation device that has a simple structure, has few failures, and can exhibit a stable function.

(Means for Solving the Problems) Therefore, the present invention provides a liquid circulation device that circulates a liquid by providing two pumps using air as a drive source and operating the two pumps alternately. The two pumps are provided with a discharge port and a suction port in a casing that contains liquid, a valve for opening and closing the discharge port is provided at the discharge port, and a valve for opening and closing the suction port is provided at the suction port. , The casing is provided with an air inlet nozzle,
The air inlet nozzle of the one pump is connected to the first port of the air distributor, the air inlet nozzle of the other pump is connected to the second port of the air distributor, and the discharge ports of the two pumps are connected. And a suction port are connected to a common liquid tank, and the air distributor rotates the rotor so that the two pumps are alternately connected to the air source and when one pump is connected to the air source, the other pump is connected. Is an air distributor that communicates with the exhaust system.

(Operation) Since the present invention is configured in this way, it has the following effects. That is, the two pumps driven by air are
A discharge port and a suction port are provided in a casing that stores liquid,
The discharge port is provided with a valve for opening and closing the discharge port, the suction port is provided with a valve for opening and closing the suction port, and the casing is provided with an air inlet nozzle. The inlet nozzle is connected to the first port of the air distributor, and the air inlet nozzle of the other pump is connected to the second port of the air distributor, while the discharge and suction ports of the two pumps are common. Since it was connected to the liquid tank, a closed circulation circuit from the discharge port of the pump to the suction port of the pump via the tank that stores the liquid,
It becomes possible to form for each of the two pumps, and the rotation of the rotor causes the air distributor to alternately connect the two pumps to the air source and to connect one pump to the air source. Since it is an air distributor that connects the other pump to the exhaust system when they communicate with each other, the pressure inside the casing of one pump is increased, and this increase in pressure closes the butterfly valve and opens the on-off valve to discharge the liquid from the discharge port. , The inside of the casing of the other pump is open to the atmosphere,
Since it is possible to open the valve at the same time as closing the open / close valve and suck the liquid, and since the liquid tank is common, the liquid is discharged from one pump to the common tank and the other pump common tank. By sucking the liquid inside and alternating this, it is possible to form a closed circulation circuit between the two pumps via a common tank.

(Example) Hereinafter, the Example of this invention is described based on an accompanying drawing.

FIG. 1 shows the overall structure of the liquid circulation device according to the present invention. In the figure, the same elements as those shown in FIGS. 5 and 6 are designated by the same reference numerals, and the description thereof will be omitted. The feature of this embodiment is that two pumps 1a and 1b are connected to one diaphragm type blower 22 driven by a motor 21, and an air distributor 24 driven by a motor 23 is provided in the middle of the connection circuit.
It is in the point of interposing.

As shown in FIGS. 2 to 4, the air distributor 24 includes a casing 25 and bearings 26, 2 in the casing 25.
And a rotor 27 that is rotatably fitted in through. The rotor 27 has its stop ring 28, 28 fixed to the peripheral surface thereof engaged with the end surface of the bearing 26 so as to prevent the rotor 27 from coming off in the axial direction. A sprocket 29 is fixed to one end of the rotor 27, and a chain (not shown) is wound between the sprocket 29 and the motor 23. That is,
The rotor 27 is rotationally driven by the operation of the motor 23. On the other hand, a cover 30 is provided on the end surface of the casing 25 opposite to the end surface facing the sprocket 29.
Are fastened with bolts 32 via packing 31.
The cover 30 is provided at its center with a mouth 30a to which a pipe 32c (FIG. 1) connecting to the blower 22 is connected.

The casing 25 has a first port 33 to which a pipe 32a (FIG. 1) connected to one pump 1a is connected and a second port to which a pipe 32b (FIG. 1) connected to the other pump 1b is connected. And a second chamber 36 defined by the rotor 27 and facing the first port 33, and a second chamber 36 defined by the rotor 27 and facing the second port 34. It is equipped with.

Further, the rotor 27 has the cover 30 on the same line.
And a bottomed second hole 38 opening toward the outside on the side opposite to the cover, which are independently provided, and from the peripheral surface thereof, Hole 3 in 1
Second through-hole 4 penetrating from the peripheral surface to the bottom of the second hole 38 as well as the first through-hole 39 penetrating to the bottom of No. 7
0 is provided at the opposite site.

Reference numerals 41 and 41 are O-rings that seal the first and second chambers 35 and 36 from the outside.

With such a configuration, first, the blower 22 is driven by the operation of the motor 21, and the rotor 27 in the air separator 24 is rotated by the operation of the motor 23. As a result, when the rotor 27 is positioned in the state shown in FIGS. 2 to 4, the air discharged from the blower 22 has the opening 30a of the cover 30 → the first hole 37 of the rotor 27 → the first Through hole 3
9 → First chamber 35 → First port 33 → Pipe 32a is fed into one pump 1a, and the pump 1a performs a pumping action. At this time, the other pump 1b is
The pipe 32b is connected to the outside through the second port 34, the second chamber 36, the second through hole 40, and the second hole 38.
The air in the pump 1b is exhausted. Next, the rotor 27
However, when the second through hole 40 is positioned so as to face the first chamber 35, one pump 1a communicates with the exhaust system and the other pump 1b communicates with the blower 22, contrary to the above. , This time the other pump 1b performs the pumping action.

That is, the supply / exhaust systems for the two pumps 1a and 1b are switched following the rotation of the rotor 27 of the air separator 24, and the alternate operation of the two pumps 1a and 1b is ensured.

Then, two pumps 1a and 1b driven by air are used.
Is provided with a discharge port 10 and a suction port 11 at the bottom of a casing 9 for containing liquid, a valve 12 for opening and closing the discharge port 10 and a butterfly valve 13 for opening and closing the suction port 11 are provided at the bottom of the casing 9. , The casing 9 is provided with an air inlet nozzle to which the pipes 32a and 32b are connected, and one pump
1a air inlet nozzle to air distributor 24 first port 33
And the air inlet nozzle of the other pump 1b is connected to the second port 34 of the air distributor 24, and the discharge port 10 and the suction port 11 of the two pumps 1a and 1b are connected to the common liquid tank A. , B are connected to the pump 1a (1b) through the discharge ports 10 of the pump 1a (1b) via the tanks A and B which store the liquid.
It is possible to form a closed circulation circuit to the suction port 11 of b) for each of the two pumps 1a and 1b, and the rotation of the rotor 27 causes the air distributor 24 to Since the base pumps 1a and 1b are alternately communicated with the air source 22, and when the one pump 1a is communicated with the air source 22, the other pump 1b is communicated with the exhaust system, so that one of the The pressure inside the casing 9 of the pump 1a is increased, and the pressure increase causes the butterfly valve 11 to close and the open / close valve 12 to open to discharge the liquid from the discharge port 10, and the other pump 1b.
The inside of the casing 9 is opened to the atmosphere, the opening / closing valve 12 is closed, and at the same time, the butterfly valve 13 can be opened to suck the liquid, and the liquid tanks A and B are common, so The liquid is discharged from 1a to the common tank A, the other pump 1b sucks the liquid in the common tank B, and by alternately performing this, two pumps 1a via the common tanks A and B are used. It is possible to form a closed circuit between 1 and 1b.

Although the diaphragm blower 22 is used as the air source in the above embodiment, the present invention may use another air source instead. Further, in the above-mentioned embodiment, the application example to the coating equipment is shown, but the present invention is not limited to this, and it is needless to say that the present invention can be applied to equipment using other liquids.

(Effects of the Invention) As described above in detail, in the liquid circulation device according to the present invention, the two pumps that use air as a drive source are provided with a discharge port and a suction port in the casing that stores the liquid, The discharge port is provided with a valve for opening and closing the discharge port, the suction port is provided with a valve for opening and closing the suction port, and the casing is provided with an air inlet nozzle. Connect to the first port of the distributor, connect the air inlet nozzle of the other pump to the second port of the air distributor, and connect the outlet and inlet of the two pumps to a common liquid tank Therefore, a closed circulation circuit from the discharge port of the pump to the suction port of the pump via the tank that stores the liquid can be formed for each of the two pumps.

The air distributor is an air distributor that alternately connects the two pumps to the air source by rotating the rotor, and when one pump communicates with the air source, the other pump communicates with the exhaust system. When the pressure inside the casing of one pump is increased, the valve is closed by this pressure increase to open the opening / closing valve, liquid is discharged from the discharge port, and the inside of the casing of the other pump is released to the atmosphere and the opening / closing valve is closed. At the same time, the valve can be opened to suck the liquid.

Since the liquid tank is common, the liquid is discharged from the one pump to the common tank, the liquid in the common tank is sucked by the other pump, and by alternately performing this, the common tank is passed through. It is possible to form a closed circuit between two pumps. This has the following effects.

As in the conventional case, a valve for switching the air is not required, and only one air source is required, which can significantly simplify the structure.

By simplifying the above structure, it is possible to reduce the equipment cost, the installation space, and the maintainability.

By eliminating the use of valves, which have many failures, the durability of the device is significantly increased, and functional stabilization can be achieved.

[Brief description of drawings]

FIG. 1 is a system diagram showing the entire structure of the liquid circulation device according to the present invention, and FIGS. 2 to 4 are structural diagrams of an air distributor, which is a part thereof. The figure is a longitudinal sectional view, FIG. 3 is a sectional view taken along the line III-III in FIG. 2, and FIG.
Sectional drawing which follows the IV-IV arrow line of a figure, FIG. 5 is a systematic diagram which shows the whole structure of the conventional liquid circulation apparatus, and FIG. 6 is a schematic diagram which shows the structure of the pump which is one part. 1a, 1b …… Pump, 22 …… Blower (air source) 24 …… Air separator, 27 …… Rotor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuo Hori, 239 Shimoshiota, Narumi-cho, Midori-ku, Nagoya, Aichi Prefecture, Nagoya Nadacuro Co., Ltd. (72) Inventor Shimitsu Kurokawa 11-4 Nishikomatsugawa-cho, Edogawa-ku, Tokyo No. KOKI HOT INDUSTRY CO., LTD. (56) References JP-A-52-63574 (JP, A)

Claims (1)

[Claims] 1. A liquid circulating device for circulating a liquid by providing two pumps (1a), (1b) using air as a drive source and alternately operating the two pumps (1a), (1b). In, the two pumps (1a), (1b) are casings for containing liquid
The discharge port (10) and the suction port (11) are provided in (9), and the discharge port (10)
Is provided with a valve (12) for opening and closing the discharge port (10), a valve (13) for opening and closing the suction port (11) at the suction port (11), and an air inlet for the casing (9). It is formed by providing a nozzle, while connecting the air inlet nozzle of the one pump (1a) to the first port (33) of the air distributor (24),
Connect the air inlet nozzle of the other pump (1b) to the air distributor (24).
Connected to the second port (34) of one of the two pumps (1a),
Liquid tank with common outlet (10) and inlet (11) of (1b)
Connected to (A) and (B), the air distributor (24) alternately connects the two pumps (1a) and (1b) to the air source (22) by rotating the rotor (27). The pump (1a) to the air source (22)
A liquid circulation device characterized by being an air distributor (24) that communicates the other pump (1b) with the exhaust system when communicating with the liquid.