JP7493239B2 - Liquid volume adjustment mechanism, metering pump equipped with liquid volume adjustment mechanism, and liquid filling system - Google Patents

Description

The present invention relates to a liquid volume adjustment mechanism, a metering pump equipped with the liquid volume adjustment mechanism, and a liquid filling system.

Conventionally, metering pumps capable of accurately delivering a fixed amount of liquid are well known. However, if there are mechanical sliding parts inside a metering pump, it is usually necessary to apply a lubricant such as grease to those parts to reduce friction and ensure smooth movement, but if the liquid being handled is an organic solvent such as alcohol or acetone, such lubricants will dissolve in the organic solvent and become useless. Furthermore, in pumps that are driven by a motor or electricity, there is a risk of ignition due to sparks or heating if the liquid being handled is a highly flammable organic solvent such as alcohol or acetone.

In recent years, metering pumps that do not have mechanical sliding parts have been developed (see Patent Documents 1 and 2, etc.). The metering pumps described in Patent Documents 1 and 2 use Bernoulli's theorem to suck up liquid. When pressurized air is passing through the air passage pipe, the reduced pressure chamber connected to the small diameter part in the air passage pipe is reduced in pressure, so that the cylinder part connected to the reduced pressure chamber is in a suction state in which it sucks up liquid. When the liquid level in the cylinder part subsequently reaches the upper limit, the exhaust side of the small diameter part is closed, so that pressurized air is sent from the small diameter part to the reduced pressure chamber, and the cylinder part is in a discharge state in which it discharges liquid. In this way, the metering pumps described in Patent Documents 1 and 2 that suck up and discharge liquid by controlling the pressurized air are highly useful because they can handle not only non-flammable liquids but also highly flammable organic solvents such as alcohol and acetone.

Patent No. 4589623 Japanese Patent No. 4860171

By the way, brake part cleaners (cleaning agents) used in vehicle inspection and maintenance shops and the like are increasingly being switched from the conventional petroleum-based types to non-flammable types, due to considerations of the global environment and user safety. Non-flammable cleaners that have the same drying time and cleaning power as petroleum-based cleaners have also already been developed. From the perspective of reducing waste, the most desirable way to use such safe and powerful cleaners is to transfer only the required amount from a large-capacity pail (e.g., 20 kg) to a reusable, portable spray can (e.g., a low-cost one that can be used more than 3,000 times) and use it up each time.

However, because the conventional metering pumps mentioned above are designed to always suck up a fixed amount of liquid, in order to transfer only the required amount into a spray can, the user must, for example, stop the supply of pressurized air at an appropriate time while the pump is sucking up liquid. Furthermore, if a control switch for stopping the supply of pressurized air were to be provided on the metering pump, it would be desirable for the above-mentioned advantage of the metering pump (the advantage of being able to safely handle flammable cleaning fluids) to be preserved.

Therefore, the present invention has been made in consideration of the above problems, and aims to provide a liquid volume adjustment mechanism that combines safety and operability suitable for transferring only the required amount of liquid, and a metering pump and liquid filling system equipped with the liquid volume adjustment mechanism.

In order to solve the above problems, the present invention provides a liquid amount adjustment mechanism for a metering pump, which, when pressurized air is passing through an air passing tube, reduces the pressure of a pressure reduction chamber communicating with a small diameter portion midway through the air passing tube, thereby putting a cylinder portion communicating with the pressure reduction chamber into a suction state, and, when an exhaust side of the small diameter portion is closed, sends pressurized air from the small diameter portion to the pressure reduction chamber, thereby putting the cylinder portion into a discharge state,
the exhaust pipe is provided separately from the air passage pipe and is supplied with pressurized air together with the air passage pipe; a diaphragm which expands and contracts the external exhaust pipe according to the air passing state in the air passage pipe; a changeover valve which opens and closes the exhaust side of the small diameter portion and the external exhaust pipe in conjunction with the diaphragm while maintaining an inverted relationship between the open/closed state of the exhaust side of the small diameter portion and the open/closed state of the external exhaust pipe; and a control switch for manually operating the diaphragm and the changeover valve, so that when the exhaust side of the small diameter portion is closed by operation of the control switch while the cylinder portion is in a suction state, the cylinder portion can be forcibly transitioned from the suction state to the discharge state.

In order to solve the above problem, the present invention described in claim 2 is characterized in that, in the liquid volume adjustment mechanism of the metering pump described in claim 1, a float valve is provided that temporarily closes the air suction path from the small diameter portion to the decompression chamber when the liquid level in the decompression chamber reaches an upper limit, so that the cylinder portion automatically transitions from the suction state to the discharge state when the liquid volume in the cylinder portion reaches an upper limit without operating the control switch.

To solve the above problem, the present invention described in claim 3 is characterized in that in the liquid volume adjustment mechanism of the metering pump described in claim 1 or 2, the switching valve is attached to a valve shaft common to the diaphragm, and the valve shaft can be operated by the control switch.

To solve the above problem, the present invention described in claim 4 is characterized in that in the liquid volume adjustment mechanism of the metering pump described in claim 3, the valve shaft further includes a coil spring for assisting the return of the control switch after the control switch is operated.

In order to solve the above problem, the present invention described in claim 5 is characterized in that the liquid volume adjustment mechanism of the metering pump described in any one of claims 1 to 4 further includes a communication pipe that connects the pressure reduction chamber and the cylinder portion, and the communication pipe is configured so that the liquid level can be visually confirmed.

In order to solve the above problem, the present invention described in claim 6 is characterized in that in the liquid volume adjustment mechanism of the metering pump described in claim 5, the communication tube has a scale for measuring the liquid sucked up into the cylinder portion in real time.

In order to solve the above problem, the present invention described in claim 7 provides a metering pump equipped with a liquid volume adjustment mechanism for a metering pump described in any one of claims 1 to 6.

In order to solve the above problem, the present invention described in claim 8 is a liquid filling system equipped with the metering pump described in claim 7, characterized in that it includes a clamp for fixing a portable container that contains the liquid discharged by the metering pump, and a mechanical switch that starts the supply of pressurized air from an air source to the liquid volume adjustment mechanism when the portable container is fixed, and stops the supply of pressurized air from the air source to the liquid volume adjustment mechanism when the fixation is released.

In order to solve the above problem, the present invention described in claim 9 is characterized in that, in the liquid filling system described in claim 8, an air-operated valve is provided midway along a liquid suction pipe that connects a storage container that stores liquid to the cylinder portion, and the air-operated valve opens the liquid suction pipe when the supply of pressurized air to the liquid volume adjustment mechanism begins.

According to the liquid volume adjustment mechanism and the metering pump and liquid filling system equipped with the liquid volume adjustment mechanism of the present invention, the user can quickly reverse the open/closed state of the exhaust side of the small diameter section and the external exhaust pipe by simply operating the control switch while liquid is being sucked up into the cylinder section of the metering pump, and transition the cylinder section from the suction state to the discharge state. Moreover, the main parts required for this reversal are only the manually operated control switch, the diaphragm, and the switching valve located outside the cylinder section. This realizes a liquid volume adjustment mechanism, metering pump, and liquid filling system that combine safety and operability suitable for transferring only the required amount of liquid.

FIG. 1 is a schematic diagram of an embodiment of a liquid filling system according to the present invention. FIG. 2(1) is an enlarged view of the liquid amount adjusting mechanism and its surroundings in FIG. 1 (during suction), and FIG. 2(2) is a partially enlarged view of FIG. 2(1). FIG. 3 is an enlarged view of the liquid amount adjusting mechanism and its periphery in FIG. 1 (during ejection). FIG. 4 is a flow chart illustrating the operation of the liquid filling system. FIG. 5 is an explanatory diagram illustrating the state of the liquid filling system at the start of suction (second step). FIG. 6 is an explanatory diagram for explaining the state of the liquid filling system when the control switch is operated (step 2B). FIG. 7 is an explanatory diagram illustrating the state of the liquid filling system when suction is completed (third step). FIG. 8 is an explanatory diagram illustrating the state of the liquid filling system at the start of filling (fourth step). FIG. 9 is an explanatory diagram illustrating the state of the liquid filling system when filling is completed (fifth step).

Below, an embodiment of a liquid volume adjustment mechanism and a metering pump equipped with a liquid volume adjustment mechanism and a liquid filling system according to the present invention will be described with reference to the drawings.

[General configuration of liquid filling system]
Fig. 1 is a schematic diagram of an embodiment of a liquid filling system according to the present invention. As shown in Fig. 1, the liquid filling system 1 of this embodiment generally includes a storage container 50, a metering pump 10, a liquid amount adjustment mechanism 8, an air source 80, a mechanical air valve 81, an air regulator 9, a holding mechanism 6a, a clamp 6, and the like.

The storage container 50 is an airtight liquid can weighing 20 kg that stores non-flammable cleaning liquid 51 for cleaning brake parts, for example. When the amount of cleaning liquid 51 stored in the storage container 50 becomes low, the manager of the liquid filling system 1 removes the storage container 50 and replaces it with a new storage container 50 filled with cleaning liquid 51.

The metering pump 10 is a pump that draws up a predetermined or required amount of cleaning liquid 51 from the storage container 50 and discharges the drawn-up cleaning liquid 51 toward the portable container 70. The configuration of this metering pump 10 will be described in detail later.

The portable container 70 is a container for filling the cleaning liquid 51 stored in the storage container 50, and is, for example, a reusable and portable spray can. A user of the liquid filling system 1 can transfer the required amount of cleaning liquid 51 into this portable container 70, carry the cleaning liquid 51 to the desired location, and clean brake parts.

The liquid volume adjustment mechanism 8 is a mechanism that uses pressurized air to control the timing at which the metering pump 10 sucks up the cleaning liquid 51 and the timing at which the metering pump 10 discharges the cleaning liquid 51. Note that while the liquid volume adjustment mechanism 8 is disposed close to the top of the metering pump 10 in FIG. 1, it may be disposed at a position away from the metering pump 10. The configuration of this liquid volume adjustment mechanism 8 will be described in detail later.

The air source 80 is a compressor that generates the pressurized air to be supplied to the liquid volume adjustment mechanism 8.

The mechanical air valve 81 is a valve that opens and closes the flow path of the pressurized air generated by the air source 80, and opens and closes the flow path depending on whether the mechanical switch 81a is on or off.

The air regulator 9 is a control device that keeps the operating pressure of the liquid volume adjustment mechanism 8 below a predetermined pressure (e.g., 0.8 MPa).

The holding mechanism 6a is a mechanism for fixing the portable container 70 to a mounting table (not shown).

The clamp 6 is an operating lever that drives the holding mechanism 6a to secure/unlock the portable container 70 to the mounting table. A user of the liquid filling system 1 can place an empty portable container 70 on the mounting table and operate the clamp 6 to secure the portable container 70 to the mounting table with the holding mechanism 6a. In addition, a user of the liquid filling system 1 can automatically start the operation of the liquid filling system 1 by performing the operation of securing the portable container 70.

[Cleaning fluid flow path]
In the liquid filling system 1 of this embodiment, a suction unit 52, a liquid suction pipe 53, an air operated valve 32, a check valve 31a, and a suction port 30in of the cylinder section 30 are arranged in this order in the flow path of the cleaning liquid 51 from the storage container 50 to the metering pump 10. Also, a discharge port 30out of the cylinder section 30, a valve 35b, a filling path 72, and a filling valve 71 are arranged in this order in the flow path of the cleaning liquid 51 from the metering pump 10 to the portable container 70.

The cleaning liquid 51 stored in the storage container 50 is therefore sucked up into the cylinder section 30 of the metering pump 10 via the suction unit 52, the liquid suction pipe 53, the air operated valve 32, the check valve 31a, and the suction port 30in of the metering pump 10. The cleaning liquid 51 sucked up into the cylinder section 30 is then filled into the portable container 70 via the discharge port 30out of the cylinder section 30, the valve 35b, the filling path 72, and the filling valve 71.

[Compressed air flow path]
In the liquid filling system 1 of this embodiment, a joint 100, an air inflow path 101, a mechanical air valve 81, an air inflow path 95, a joint 100, an air regulator 9, and an air inflow path 92 are arranged in this order in the flow path of pressurized air from the air source 80 to the liquid volume adjustment mechanism 8. In addition, an air inflow path 91 is also arranged in parallel to the air inflow path 92 in the flow path of pressurized air from the air regulator 9 to the liquid volume adjustment mechanism 8. In addition, an air inflow path 82 is arranged in parallel to the air inflow path 95 in the flow path of pressurized air from the mechanical air valve 81 to the air operated valve 32.

Therefore, the pressurized air generated by the air source 80 is supplied to the air passage 16 (described later) of the liquid volume adjustment mechanism 8 via the joint 100, the air inlet passage 101, the mechanical air valve 81, the air inlet passage 95, the joint 100, the air regulator 9, and the air inlet passage 91. The pressurized air on the outlet side of the air regulator 9 is supplied to the external exhaust pipe 14 (described later) of the liquid volume adjustment mechanism 8 via the air inlet passage 91. The pressurized air on the outlet side of the mechanical air valve 81 flows into the air operated valve 32 via the air inlet passage 82.

[Configuration of the metering pump]
1, the metering pump 10 includes, in order from the storage container 50 side, a check valve 31a, a suction port 30in provided at the bottom of the cylinder portion 30, the cylindrical cylinder portion 30, a reduced pressure chamber 20 arranged above the cylinder portion 30, and a discharge port 30out provided in the side wall at the lower end side of the cylinder portion 30. Of these, the lower opening of the reduced pressure chamber 20 is connected to the upper opening of the cylinder portion 30, and a float 25 that rises together with the liquid level is accommodated inside the reduced pressure chamber 20.

A communication pipe 40 that connects the cylinder section 30 and the decompression chamber 20 is attached to the outer wall of the metering pump 10, and this communication pipe 40 is made of a transparent tube made of a material such as glass so that the liquid level inside can be visually confirmed. Furthermore, a scale (not shown) is displayed on the surface of this communication pipe 40, so that the cleaning liquid 51 sucked up into the cylinder section 30 can be measured in real time.

[Configuration of liquid volume adjustment mechanism]
Fig. 2(1) is an enlarged view of the liquid amount adjustment mechanism and its periphery in Fig. 1 (during suction), Fig. 2(2) is a partial enlarged view of Fig. 2(1), and Fig. 3 is an enlarged view of the liquid amount adjustment mechanism and its periphery in Fig. 1 (during discharge). As shown in Figs. 2 and 3, the liquid amount adjustment mechanism 8 includes an air passage pipe 16, an external exhaust pipe 14, a diaphragm 85, a switching valve B, a control switch 8A, a bypass pipe 18, etc.

The air passage tube 16 is connected to the air inlet passage 92 described above. The pressurized air supplied from the air inlet passage 92 to the air passage tube 16 flows in from the injection side 16-1 of the air passage tube 16, passes through the small diameter portion 16-2, and is then discharged to the outside from the exhaust side 16-3. The small diameter portion 16-2 is set to have a relatively small diameter compared to the injection side 16-1 and the exhaust side 16-3, and this small diameter portion 16-2 is connected to the reduced pressure chamber 20 (see FIG. 1) of the metering pump 10 via the suction passage 17.

The external exhaust pipe 14 is an exhaust pipe provided separately from the air passage pipe 16, and is connected to the air inlet passage 91 described above. The pressurized air supplied from the air inlet passage 91 to the external exhaust pipe 14 flows from the injection side 14-1 to the exhaust side 14-2 of the external exhaust pipe 14, and is then discharged to the outside. The space between the injection side 14-1 and the exhaust side 14-2 of the external exhaust pipe 14 is an area that can be opened and closed by the diaphragm 85 (upper chamber 14A of the diaphragm 85 (see Figure 3)). A throttle valve 82 is provided on the exhaust side 14-2 of the external exhaust pipe 14.

The diaphragm 85 expands and contracts the upper chamber 14A (see FIG. 3) of the diaphragm 85 according to the air passing state in the air passage tube 16. Directly below the diaphragm 85 (upper area 14B-1 of the lower chamber 14B of the diaphragm 85) are arranged a diaphragm guide 86 and a sheet packing (e.g., made of fluororesin) 87. The sheet packing 87 divides the lower chamber 14B of the diaphragm 85 into an upper area 14B-1 and a lower area 14B-2 as necessary. The operation of the diaphragm 85 and the sheet packing 87 will be described in detail later.

The switching valve B is a valve that opens and closes the exhaust side 16-3 of the air passage tube 16 and the external exhaust tube 14 in conjunction with the diaphragm 85 while maintaining the open/closed state of the exhaust side 16-3 of the air passage tube 16 and the open/closed state of the external exhaust tube 14 in an inverted relationship. As shown enlarged in FIG. 2 (2), the switching valve B is attached to a valve shaft 88 common to the diaphragm 85, and a valve shaft 83 and a valve packing 84 for opening and closing the external exhaust tube 14 (upper chamber 14A of the diaphragm 85) are attached to the upper end side of this valve shaft 88, and a valve packing 89 for opening and closing the exhaust side 16-3 of the air passage tube 16 is attached to the lower end side of the valve shaft 88. A coil spring 8a is arranged around the valve shaft 88 that exists in the lower area 14B-2 of the lower chamber 14B of the diaphragm 85. This coil spring 8a has the function of assisting the return of the control switch 8A and the diaphragm 85.

The control switch 8A is a push button type switch for operating the diaphragm 85 and the switching valve B that is linked to it. Note that the type of the control switch 8A is not limited to a push button type, but the following will assume that it can be pushed downward.

The bypass pipe 18 is a passageway that connects the lower area 14B-2 of the lower chamber 14B of the diaphragm 85 with the suction passage 17. The bypass pipe 18 has the function of depressurizing/pressurizing the lower chamber 14B of the diaphragm 85 depending on the air passing state in the air passage pipe 16 (details will be described later).

[Basic operation of the liquid volume adjustment mechanism]
In the liquid amount adjusting mechanism 8 configured as described above, when pressurized air is passing through the air passage tube 16, the pressure reduction chamber 20 communicating with the small diameter portion 16-2 in the air passage tube 16 is reduced in pressure according to Bernoulli's theorem, and the cylinder portion 30 communicating with the pressure reduction chamber 20 (see FIG. 1) is brought into a suction state (a state in which cleaning liquid 51 is sucked up from a suction port 30in). At this time, the lower chamber 14B of the diaphragm 85 communicating with the suction path 17 is also reduced in pressure. On the other hand, when the exhaust side 16-3 of the small diameter portion 16-2 is closed, pressurized air is sent from the small diameter portion 16-2 to the pressure reduction chamber 20, and the cylinder portion 30 is brought into a discharge state (a state in which cleaning liquid 51 is discharged from a discharge port 30out).

[Diaphragm operation]
(1) When the lower chamber 14B of the diaphragm 85 is in a negative pressure state (however, the negative pressure is equal to or greater than a predetermined value):
The lower chamber 14B of the diaphragm 85 is in a state of a single chamber that is not divided into the upper area 14B-1 and the lower area 14B-2, and the overall cross-sectional area of the lower chamber 14B maintains a state equal to the cross-sectional area of the upper chamber 14A of the diaphragm 85. At this time, the diaphragm 85 is flat (FIG. 2).

(2) When the pressure in the lower chamber 14B decreases from the state of (1) and falls below a predetermined value:
The diaphragm 85 is deformed, and the lower chamber 14B of the diaphragm 85 is separated into the upper area 14B-1 and the lower area 14B-2 by the sheet packing 87, and the upper area 14B-1 maintains a negative pressure state. At the same time, pressurized air is introduced into the upper chamber 14A of the diaphragm 85 (FIG. 3).

(3) When the lower chamber 14B of the diaphragm 85 is changed from the state of (2) to the pressurized state:
The pressurized air introduced from the suction passage 17 through the bypass pipe 18 flows only into the lower area 14B-2 of the lower chamber 14B. This state is maintained until the difference between the cross-sectional area of the lower chamber 14B of the diaphragm 85 and the cross-sectional area of the upper chamber 14A of the diaphragm 85 disappears and the state returns to (1).

(4) When the supply of compressed air stops:
Since a small amount of air is constantly exhausted to the outside from the exhaust side 14-2 of the external exhaust pipe 14, when the supply of pressurized air is stopped, the air in the upper chamber 14A of the diaphragm 85 disappears and the diaphragm 85 returns to its flat plate shape.

[Switching valve operation]
When the diaphragm 85 is flat (FIG. 2(1)), the switching valve B closes the external exhaust pipe 14 and opens the exhaust side 16-3 of the small diameter portion 16-2. On the other hand, when the diaphragm 85 is deformed (FIG. 3), the switching valve B opens the external exhaust pipe 14 and closes the exhaust side 16-3 of the small diameter portion 16-2.

Specifically, in the state shown in FIG. 2 (1), the control switch 8A located on the upper end side of the valve shaft 88 (the upper end side of the valve shaft 83) is not pressed downward, so the valve packing 89 on the lower end side opens the exhaust side 16-3 of the small diameter section 16-2, and the valve packing 84 on the upper end side closes the external exhaust pipe 14.

On the other hand, in the state shown in FIG. 3, the control switch 8A located at the upper end of the valve shaft 88 (the upper end of the valve shaft 83) is pressed downward, so that the valve packing 89 on the lower end closes the exhaust side 16-3 of the small diameter section 16-2, and the valve packing 84 on the upper end opens the external exhaust pipe 14.

[Control switch operation]
2(1), when the control switch 8A is pressed down to transition to the state shown in Fig. 3, the pressurized air supplied to the air passage tube 16 is sent from the small diameter portion 16-2 to the reduced pressure chamber 20, and the cleaning liquid 51 that had been sucked up into the cylinder portion 30 up to that point begins to be discharged. Therefore, the liquid amount adjustment mechanism 8 of this embodiment is designed to forcibly transition the cylinder portion 30 from the suction state to the discharge state by operating the control switch 8A.

[Float operation]
A float valve B3 is provided at the top end of the float 25 in the decompression chamber 20. This float valve B3 temporarily closes the air suction passage 17 when the liquid level in the decompression chamber 20 reaches an upper limit. This stops the suction of air from the decompression chamber 20 to the suction passage 17, causing a sudden drop in the pressure of the air passing through the small diameter section 16-2 (a sudden drop in the pressure on the exhaust side 16-3). As a result, the diaphragm 85 deforms (FIG. 3), causing the cylinder section 30 to automatically transition from the suction state to the discharge state without operating the control switch 8A.

[Other controls using pressurized air]
1, the liquid filling system 1 of this embodiment includes a clamp 6 for fixing a portable container 70 that contains cleaning liquid 51 discharged by a metering pump 10 to a mounting table (not shown), and a mechanical switch 81a that starts the supply of pressurized air from an air source 80 to the metering pump 10 when the portable container 70 is fixed and stops the supply of pressurized air from the air source 80 to the metering pump 10 when the fixation is released. This mechanical switch 81a is, for example, a mechanical switch for opening and closing a mechanical air valve 81 in Fig. 1, and is turned on (valve open) when the holding mechanism 6a fixes the portable container 70 by operating the clamp 6, and is turned off (valve closed) when the holding mechanism 6a releases the fixation of the portable container 70 by operating the clamp 6.

Therefore, the supply of pressurized air to the liquid volume adjustment mechanism 8 is automatically started when the portable container 70 is fixed, and the supply of pressurized air to the liquid volume adjustment mechanism 8 is automatically stopped when the portable container 70 is released. In other words, the user of the liquid filling system 1 can simultaneously fix/release the portable container 70 and supply/stop the pressurized air by operating the clamp 6.

In addition, as described above, in the liquid filling system 1 of this embodiment, the air operated valve 32 is provided in the middle of the liquid suction pipe 53 that connects the storage container 50 storing the cleaning liquid 51 to the cylinder portion 30, and this air operated valve 32 is also connected to the above-mentioned mechanical air valve 81. Therefore, when the supply of pressurized air to the liquid volume adjustment mechanism 8 starts, the air operated valve 32 automatically opens the liquid suction pipe 53, and when the supply of pressurized air to the liquid volume adjustment mechanism 8 stops, the air operated valve 32 automatically closes the liquid suction pipe 53. Therefore, in this embodiment, unnecessary suction from the storage container 50 to the metering pump 10 can be prevented.

[Configuration of suction unit]
Furthermore, in the liquid filling system 1 of this embodiment, as described above, the liquid suction pipe 53 is connected to the storage container 50 via the suction unit 52, and the suction unit 52 is provided with a check valve 52a for releasing negative pressure to prevent the inside of the storage container 50 from becoming negative pressure and becoming a resistance to suction to the cylinder portion 30. The suction unit 52 is attached so as to be in close contact with the opening of the storage container 50, and the liquid suction pipe 53 is attached via a connection joint 52c that can be fixed to the suction unit 52. Therefore, the manager of the liquid filling system 1 of this embodiment can safely replace the heavy storage container 50 while preventing the backflow of the cleaning liquid 51 from the metering pump 10 to the storage container 50.

[Operation flow of liquid filling system]
The flow of the operation of the liquid filling system of this embodiment will be described below. Fig. 4 is a flow chart for explaining the operation of the liquid filling system. As shown in Fig. 4, the liquid filling system 1 sequentially executes a waiting step (first step S1) before suction when the portable container 70 is not fixed by the clamp 6, a suction start step (second step S2) immediately after the portable container 70 is fixed by the clamp 6, a suction completion step (third step S3) when the amount of the cleaning liquid 51 in the cylinder section 30 reaches an upper limit, a filling start step (fourth step S4) in which the cylinder section 30 starts discharging the cleaning liquid 51 sucked up toward the portable container 70, and a filling completion step (fifth step S5) in which the filling of the portable container 70 is completed.

However, in the liquid filling system 1 of this embodiment, when the switch operation step (step S2B) of pressing down the control switch 8A is executed after the start of suction (after execution of step S2), even if the amount of cleaning liquid 51 in the cylinder portion 30 has not reached the upper limit at that time, the system proceeds to the filling start step (step S4). Below, the first step S1, the second step S2, the second step S2B, the third step S3, the fourth step S4, and the preliminary fifth step S5 will be described in order.

[Standby step (first step)]
The state of the liquid filling system in the waiting step (first step) before suction is as shown in Fig. 1. In Fig. 1, the flow paths where pressurized air exists are marked with dark hatching or thick lines , the flow paths where negative pressure air exists are marked with light hatching or thin lines , and the areas where cleaning liquid exists are marked with a dot pattern (the same applies to the other figures).

First, in the state shown in FIG. 1, the clamp 6 is in an open state, and the portable container 70 is not fixed to the mounting table. In this state, the mechanical switch 81a of the mechanical air valve 81 is turned off, so pressurized air is not supplied to the liquid volume adjustment mechanism 8. Furthermore, when the mechanical switch 81a is turned off, pressurized air is not supplied to the air operated valve 32, so the liquid suction pipe 53 is closed. Therefore, in the state shown in FIG. 1, the cylinder portion 30 of the metering pump 10 does not suck up the cleaning liquid 51 from the storage container 50, and the portable container 70 is not discharged (filled) with the cleaning liquid 51.

Here, if the cleaning liquid 51 stored in the storage container 50 is highly volatile and has the property of vaporizing and expanding in a high temperature environment, the pressure in the storage container 50 may increase depending on the temperature, and the cleaning liquid 51 may flow from the storage container 50 into the metering pump 10. However, in the state shown in FIG. 1, the air-operated valve 32 closes the liquid suction pipe 53, so that it is possible to prevent the cleaning liquid 51 from flowing from the storage container 50 into the metering pump 10 even if the temperature is high. Incidentally, if the cleaning liquid 51 is highly volatile, it is desirable to use a pressure-resistant container as the storage container 50.

In addition, in this embodiment, the suction unit 52 of the storage container 50 is attached to the liquid suction pipe 53 via the connecting joint 52c, so that in the state shown in FIG. 1, the manager of the liquid filling system 1 can easily connect/disconnect a heavy storage container 50 (e.g., 20 kg) to/from the liquid suction pipe 53 while maintaining the airtightness of the storage container 50.

[Suction start step (second step)]
The state of the liquid filling system in the start step of suction (second step) is as shown in Fig. 5. In the state shown in Fig. 5, the portable container 70 is fixed to the mounting table by the clamp 6. This turns on the mechanical switch 81a of the mechanical air valve 81, and the supply of pressurized air to the liquid volume adjustment mechanism 8 is started. In addition, because the mechanical switch 81a is turned on, pressurized air is also supplied to the air operated valve 32, and the liquid suction pipe 53 is opened.

In the state shown in FIG. 5, as shown in an enlarged view in FIG. 2(1), the diaphragm 85 becomes flat, and the switching valve B opens the exhaust side 16-3 of the air passage tube 16 and closes the external exhaust tube 14 (the upper chamber 14A of the diaphragm 85). Therefore, the reduced pressure chamber 20 connected to the small diameter portion 16-2 (negative pressure generating portion) of the air passage tube 16 becomes negative pressure, and the cleaning liquid 51 in the storage container 50 is sucked up to the cylinder portion 30 of the metering pump 10. Note that as long as the reduced pressure chamber 20 is under negative pressure, the cleaning liquid 51 is not discharged from the cylinder portion 30 toward the portable container 70. In addition, in the liquid filling system 1 of this embodiment, the suction unit 52 with a check valve 52a is provided in the storage container 50, so that the occurrence of suction resistance can also be prevented.

The user of the liquid filling system 1 can check the amount of cleaning liquid 51 sucked up into the cylinder section 30 in real time by visually observing the change in the liquid level through the transparent connecting tube 40 provided along the cylinder section 30, and press the control switch 8A when the amount of liquid reaches the desired value. However, if the user of the liquid filling system 1 wishes to fill the portable container 70 (to suck up the cleaning liquid 51 to the upper limit), he or she can wait without touching the control switch 8A.

[Control switch operation process (step 2B)]
The state of the liquid filling system in the control switch operation step (step 2B) is as shown in Fig. 6. In the state of Fig. 6, the control switch 8A is pressed down, so that the diaphragm 85 is deformed as shown in the enlarged view of Fig. 3, and the switching valve B closes the exhaust side 16-3 of the small diameter portion 16-2 and opens the external exhaust pipe 14, so that exhaust from the exhaust side 16-3 of the air passage pipe 16 stops, and pressurized air passes from the injection side 14-1 to the exhaust side 14-2 of the external exhaust pipe 14 (upper chamber 14A of the diaphragm 85).

At this time, the pressurized air flowing in from the injection side 16-1 of the air passage tube 16 is sent to the reduced pressure chamber 20 via the small diameter section 16-2 and the suction path 17, so that the liquid level in the cylinder section 30 is pushed downward, and the cleaning liquid 51 that the cylinder section 30 has sucked up up to that point begins to be discharged toward the portable container 70. As a result, the cleaning liquid 51 and the pressurized air in the cylinder section 30 are filled into the portable container 70 in that order (see FIG. 9 described later). Therefore, the user of the liquid filling system 1 can freely control the ratio of cleaning liquid 51 and pressurized air filled into the portable container 70 by the timing of operating the control switch 8A.

[Completion of suction process (third process)]
The state of the liquid filling system at the completion step of the suction (third step) is as shown in Figure 7. In the state shown in Figure 7, the liquid level in the decompression chamber 20 rises to the upper limit, and the float valve B3 provided at the upper end of the float 25 closes the suction passage 17.

[Filling start step (fourth step)]
The state of the liquid filling system in the filling start step (fourth step) is as shown in Fig. 8. When the suction path 17 is closed, the pressure in the small diameter portion 16-2 (negative pressure generating portion) of the air passing tube 16 drops to the set pressure, and the pressure in the exhaust side 16-3 of the air passing tube 16 and the pressure in the lower chamber 14B of the diaphragm 85 drop, causing the diaphragm 85 to deform (Fig. 3). This results in a state similar to that when the control switch 8A is pressed down. In other words, pressurized air is sent to the decompression chamber 20 via the small diameter portion 16-2 and the suction path 17, the liquid level in the cylinder portion 30 is pushed down, and the cleaning liquid 51 in the cylinder portion 30 starts to be discharged toward the portable container 70.

[Filling completion step (fifth step)]
The state of the liquid filling system in the filling completion step (fifth step) is as shown in Fig. 9. When all of the cleaning liquid 51 in the cylinder section 30 has been filled into the portable container 70, the pressurized air in the cylinder section 30 flows into the portable device 70. When the pressure inside the portable device 70 rises to a predetermined pressure, filling is complete. Thereafter, when the user of the liquid filling system 1 operates the clamp 6 to release the fixation of the portable container 70, the supply of pressurized air to the liquid volume adjustment mechanism 8 is stopped, and the air in the liquid volume adjustment mechanism 8 is exhausted. This returns the liquid filling system 1 to the state shown in Fig. 1 (first step).

[Effects of the embodiment]
As described above, according to the liquid amount adjustment mechanism 8 and the metering pump 10 and the liquid filling system 1 equipped with the liquid amount adjustment mechanism according to this embodiment, the user of the liquid filling system 1 can quickly reverse the open/closed state of the exhaust side 16-3 of the small diameter portion 16-2 and the external exhaust pipe 14 by simply operating the control switch 8A during the suction of the cleaning liquid 51 into the cylinder portion 30 of the metering pump 10, and the cylinder portion 30 can be shifted from the suction state to the discharge state. Moreover, the main parts required for the reversal are only the control switch 8A for manual operation, the diaphragm 85, and the switching valve B arranged outside the cylinder portion 30. Therefore, the liquid amount adjustment mechanism 8 and the metering pump 10 and the liquid filling system 1 equipped with the liquid amount adjustment mechanism according to this embodiment are suitable for transferring only the required amount of cleaning liquid 51, and are safe and easy to operate.

[others]
As described above, the preferred embodiment of the present invention has been described in detail, but the present invention is not limited to the specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. For example, the liquid handled by the liquid amount adjusting mechanism 8, the metering pump 10, and the liquid filling system 1 according to the present embodiment is not limited to a non-flammable cleaning liquid for cleaning brake parts, but may be a flammable cleaning liquid or a liquid other than a cleaning liquid.

10 Metering pump 100 Joint 101 Air inlet passage 14 External exhaust pipe 14A Upper chamber 14B of diaphragm Lower chamber 14B-1 of diaphragm Upper area 14B-2 Lower area 15 Air piping 16 Air passage pipe 17 Suction passage 17a Packing 18 Bypass pipe 20 Decompression chamber 25 Float 30 Cylinder section 30in Suction port 30out Discharge port 31a Check valve 32 Air operated valve 35b Valve 40 Connecting pipe 50 Storage container 51 Cleaning liquid 52 Suction unit 53 Liquid suction pipe 6 Clamp 6a Hold mechanism 70 Portable container 71 Filling valve 72 Filling passage 8 Liquid amount adjustment mechanism 80 Air source 81 Air inlet passage 81 Control switch 81 Mechanical air valve 81a Mechanical switch 82 Air inlet passage 82 Throttle valve 83 Valve shaft 84 Valve packing 85 Diaphragm 86 Diaphragm guide 87 Seat packing 88 Valve shaft 89 Valve packing 8a Coil spring 9 Air regulator 91 Air inflow passage 92 Air inflow passage 95 Air inflow passage B Switching valve B1 First passage pipe valve B2 Second passage pipe valve B3 Float valve

Claims (9)

a liquid amount adjusting mechanism for a metering pump, which, when pressurized air is passing through an air passing tube, reduces the pressure of a pressure reduction chamber communicating with a small diameter portion midway through the air passing tube, thereby putting a cylinder portion communicating with the pressure reduction chamber into a suction state, and, when an exhaust side of the small diameter portion is closed, sends pressurized air from the small diameter portion to the pressure reduction chamber, thereby putting the cylinder portion into a discharge state,
an external exhaust pipe provided separately from the air passage pipe and to which pressurized air is supplied together with the air passage pipe;
a diaphragm that expands and contracts the external exhaust pipe according to an air passing state in the air passing pipe;
a switching valve that opens and closes the exhaust side of the small diameter portion and the external exhaust pipe in conjunction with the diaphragm while maintaining an inverted relationship between an open/closed state of the exhaust side of the small diameter portion and an open/closed state of the external exhaust pipe;
a control switch for manually operating the diaphragm and the switching valve;
By providing
A liquid volume adjustment mechanism for a metering pump, characterized in that when the exhaust side of the small diameter portion is closed by operating the control switch while the cylinder portion is in a suction state, the cylinder portion can be forcibly transitioned from the suction state to the discharge state. 2. The liquid amount adjusting mechanism for a metering pump according to claim 1,
By providing a float valve that temporarily closes the air suction passage from the small diameter portion to the decompression chamber when the liquid level in the decompression chamber reaches an upper limit,
A liquid volume adjustment mechanism for a metering pump, characterized in that the cylinder portion automatically transitions from a suction state to a discharge state when the amount of liquid in the cylinder portion reaches an upper limit without the need to operate the control switch. The liquid amount adjusting mechanism for a metering pump according to claim 1 or 2,
2. A liquid volume adjusting mechanism for a metering pump, wherein the switching valve is attached to a valve shaft common to the diaphragm, and the valve shaft can be operated by the control switch. 4. The liquid amount adjusting mechanism for a metering pump according to claim 3,
13. A liquid volume adjusting mechanism for a metering pump, comprising: a valve shaft having a coil spring for assisting the return of the control switch after the control switch is operated. The liquid amount adjusting mechanism for a metering pump according to any one of claims 1 to 4,
A communication pipe that communicates the decompression chamber with the cylinder portion is further provided,
A liquid volume adjusting mechanism for a metering pump, characterized in that the liquid level in the communicating pipe is visually confirmed. 6. The liquid amount adjusting mechanism for a metering pump according to claim 5,
2. A liquid volume adjusting mechanism for a metering pump, comprising: a communicating tube having a scale for measuring the amount of liquid drawn up into the cylinder portion in real time; A metering pump comprising a liquid volume adjustment mechanism for a metering pump according to any one of claims 1 to 6. A liquid filling system including the metering pump of claim 7,
a clamp for fixing a portable container that contains the liquid discharged by the metering pump;
a mechanical switch that starts the supply of pressurized air from an air source to the liquid volume adjustment mechanism when the portable container is fixed, and stops the supply of pressurized air from the air source to the liquid volume adjustment mechanism when the portable container is released from the fixation;
A liquid filling system comprising: 9. The liquid filling system of claim 8,
The liquid suction device further includes an air operated valve provided in a liquid suction pipe connecting a storage container storing liquid and the cylinder portion,
a liquid filling system comprising: a liquid intake mechanism that receives a liquid from the liquid volume adjusting mechanism; a liquid intake pipe that receives the liquid from the liquid volume adjusting mechanism;

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