JP7614621B2 - Liquid supply device and cleaning system - Google Patents

Description

The present invention relates to a liquid supply device and a cleaning system that supply liquid to a liquid supply target.

A liquid supplying device is known that sends liquid such as brine, whose temperature has been adjusted by a refrigeration device having a compressor, a condenser, an expansion valve, and an evaporator, to a temperature-controlled object, and adjusts the temperature of the liquid that has passed through the temperature-controlled object again by the refrigeration device (see, for example, Patent Document 1).

Also, a discharge-type liquid supply device that discharges liquid without circulating it is also known. The applicant of the present application has previously proposed a device of this type in Patent Document 2.

JP 2015-14417 A JP 2019-82280 A

In a discharge-type liquid supply device, liquid may be discharged from one or more nozzles to a liquid supply target. In this case, the flow rate of the discharged liquid can be changed by throttling the nozzle or switching the nozzle between open and closed.

However, when the flow rate is changed as described above, the pressure of the liquid flowing inside the liquid supply device fluctuates, and the pressure of the liquid supplied from the nozzle may also fluctuate. It is desirable to avoid such fluctuations in liquid pressure when it is required to supply liquid to the liquid supply target within a desired pressure range.

For example, in a liquid supply device that uses liquid discharged from a nozzle at a constant pressure for cleaning, increasing the flow rate of the liquid discharged from the nozzle can cause a drop in the pressure of the liquid being discharged. It is desirable to avoid such a drop in pressure, as it may cause a situation in which the desired cleaning power cannot be ensured. It is also possible to compensate for the drop in pressure by increasing the discharge flow rate of the pump. However, this measure is not necessarily satisfactory in terms of control responsiveness to the desired pressure and control precision.

In addition, in a liquid supply device that circulates liquid whose temperature has been controlled by a temperature regulator through a liquid supply target, the pressure of the liquid may fluctuate significantly, for example, depending on heat exchange between the liquid supply target and the liquid. As a result, the pressure of the liquid upstream of the liquid supply target may fluctuate significantly, and the flow rate of the liquid upstream of the temperature control target may change. In this case, there is a risk that the accuracy of temperature control of the liquid supply target by the liquid may decrease due to changes in the flow rate and temperature of the liquid whose temperature is controlled by the temperature regulator.

The present invention has been made in consideration of the above circumstances, and aims to provide a liquid supply device and cleaning system that can effectively prevent the supplied liquid from being disturbed from the desired state.

A liquid supply device according to one embodiment of the present invention includes a main flow path connected to a pump that sucks in and pumps out liquid in a tank, and through which the liquid pumped out from the pump flows and is sent to a liquid supply target side; a branch flow path that branches off midway through the main flow path and is connected to the tank; an adjustment valve that is provided in the branch flow path and adjusts the flow rate of the liquid flowing through the branch flow path from the main flow path to the tank; and a controller that controls the pump and the adjustment valve. The controller controls the opening of the adjustment valve so that the detection value of a pressure sensor that detects the pressure of the liquid flowing through the portion of the main flow path upstream of the connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed.

In this liquid supply device, when the pressure of the liquid flowing through the main flow path fluctuates due to some factor, such as switching the flow rate of the liquid supplied to the liquid supply target, the opening of the adjustment valve is controlled to adjust the flow rate of the liquid returning from the branch flow path, thereby controlling the pressure of the liquid pumped out from the pump toward the target pressure. This makes it possible to mitigate pressure fluctuations of the liquid in the main flow path. Specifically, when the detection value of the pressure sensor becomes larger than the target pressure, the opening of the adjustment valve is increased, and when the detection value becomes smaller than the target pressure, the opening of the adjustment valve is decreased, thereby controlling toward the target pressure and mitigating fluctuations in the pressure of the liquid in the main flow path from the target pressure. In this pressure adjustment by adjusting the opening of the adjustment valve, the pressure of the liquid is adjusted responsively and is not greatly disturbed, so that disturbances from the desired state of the liquid to be supplied can be effectively suppressed. Specifically, significant fluctuations in the pressure of the liquid from the desired pressure (target pressure) can be suppressed.

The liquid supply device according to one embodiment may further include a relief flow path that branches off from a portion of the branch flow path upstream of the adjustment valve and is connected to the tank, and a relief valve that is provided in the relief flow path and opens when the pressure upstream of the relief flow path exceeds a predetermined pressure.

This configuration can improve the control responsiveness to the target pressure when the pressure of the liquid flowing through the main flow path suddenly increases. In other words, when the pressure of the liquid flowing through the main flow path suddenly increases, the relief valve opens and the stagnation of the liquid is quickly eliminated, causing the pressure of the liquid to instantly approach the target pressure. This can improve the control responsiveness to the target pressure.

In one embodiment, the liquid supply device may further include a temperature regulator that regulates the temperature of the liquid flowing through a portion of the main flow path upstream of the connection position of the branch flow path, and the pressure sensor may detect the pressure of the liquid before the temperature is regulated by the temperature regulator.

In this configuration, the above-mentioned function of the adjustment valve suppresses fluctuations in the flow rate of the liquid flowing into the temperature regulator, preventing the flow rate and temperature of the liquid temperature-controlled by the temperature regulator from deviating from the desired state. This makes it possible to supply liquid at the desired pressure while suppressing a decrease in temperature control accuracy when controlling the temperature of a liquid supply target using liquid.

The liquid supply device according to one embodiment may be configured as a discharge type liquid supply device that discharges the liquid delivered by the main flow path to a liquid supply target.

This configuration helps to reduce pressure disturbances in the liquid being released.

The discharge-type liquid supply device according to one embodiment further includes one or more nozzles that receive the liquid delivered by the main flow path and discharge it to the liquid supply target, and the nozzles may be capable of switching between discharging and blocking the liquid and/or adjusting the flow rate when discharging.

In this configuration, by switching between releasing and blocking liquid from the nozzle and/or adjusting the flow rate of the nozzle, it is possible to suppress disturbances in the pressure of the liquid released from the nozzle even if the pressure of the liquid flowing through the main flow path fluctuates.

The liquid supply device according to one embodiment may be configured as a circulation type liquid supply device in which the liquid discharged from the main flow path is returned to the tank via a liquid supply target.

In this configuration, the pressure fluctuations of the liquid in the main flow path are mitigated by the function of the adjustment valve as described above, thereby suppressing disturbances in the flow state of the liquid passing through the liquid supply target.

Moreover, a cleaning system according to one embodiment includes a main flow path connected to a pump that sucks in and sends out liquid in a tank, and through which the liquid sent out from the pump flows and sends it to a liquid supply target side, one or more nozzles that receive the liquid sent out by the main flow path and discharge it to the liquid supply target, a branch flow path that branches off midway through the main flow path and is connected to the tank, an adjustment valve that is provided in the branch flow path and adjusts the flow rate of the liquid flowing through the branch flow path from the main flow path to the tank, and a controller that controls the pump and the adjustment valve, wherein the nozzle is capable of switching between discharging and blocking the liquid and/or adjusting the flow rate during discharging, and the controller controls an opening degree of the adjustment valve so that a detection value of a pressure sensor that detects a pressure of the liquid flowing through a portion of the main flow path upstream of a connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed,
The cleaning system performs cleaning by ejecting the liquid from the nozzle.

This cleaning system prevents the liquid used for cleaning from being disturbed from the desired state, so the cleaning effect can be maintained stably.

The present invention effectively prevents the liquid being supplied from being disturbed from the desired state.

1 is a diagram showing a schematic configuration of a liquid supplying apparatus according to a first embodiment of the present invention. FIG. 4 is a graph illustrating an example of the operation of the liquid supplying apparatus according to the first embodiment. FIG. 11 is a graph illustrating an example of a pressure adjusting operation of the liquid supply apparatus according to the first embodiment. FIG. 11 is a diagram showing another graph illustrating an example of the pressure adjustment operation of the liquid supply apparatus according to the first embodiment. 5A and 5B are diagrams illustrating an example of a pressure adjustment operation of the liquid supplying apparatus according to the first embodiment and a graph illustrating changes in the flow rate of the liquid during this operation. FIG. 13 is a diagram showing a schematic configuration of a liquid supplying apparatus according to a second embodiment of the present invention. FIG. 13 is a diagram showing a schematic configuration of a liquid supplying apparatus according to a third embodiment of the present invention.

Each embodiment of the present invention will be described below.

First Embodiment
1 is a diagram showing a schematic configuration of a liquid supplying apparatus 1 according to a first embodiment of the present invention. The liquid supplying apparatus 1 includes a tank 2 for storing liquid, a pump 3 for sucking the liquid in the tank 2 and discharging it from a discharge port, a main flow path 4 connected to the discharge port of the pump 3 and for passing the liquid discharged from the pump 3 to a liquid supply target T, and a controller 20.

In this embodiment, the upstream end of the main flow path 4 is connected to the discharge port of the pump 3, and the downstream end of the main flow path 4 is connected to the downstream distribution flow path 5. A plurality of nozzles 6 are attached to the downstream distribution flow path 5, and each nozzle 6 is connected to the downstream distribution flow path 5 so as to branch off from the downstream distribution flow path 5.

Each nozzle 6 is configured to receive the liquid discharged from the pump 3 and flowing out from the downstream end of the main flow path 4 via the downstream distribution flow path 5 and discharge it to the liquid supply target T. The liquid discharged from the nozzle 6 is then supplied to the liquid supply target T and then drained. In other words, the liquid supply device 1 according to this embodiment is configured as a discharge-type liquid supply device that discharges the liquid discharged from the main flow path 4 to the liquid supply target T via the downstream distribution flow path 5 and the nozzle 6. Each nozzle 6 can switch between discharging and blocking liquid and/or adjust the flow rate during discharge, thereby allowing liquid to be supplied to the liquid supply target T in various patterns.

The liquid supply device 1 also includes a temperature regulator 7 that regulates the temperature of the liquid flowing through the main flow path 4, thereby allowing temperature-regulated liquid to be supplied to the liquid supply target T. The temperature regulator 7 in this embodiment includes a cooler 7A and a heater 7B. However, the temperature regulator 7 may be configured to include only the cooler 7A, or may be configured to include only the heater 7B. The cooler 7A is also disposed upstream of the heater 7B, but this arrangement is not particularly limited.

The liquid that the liquid supply device 1 passes through is not particularly limited and may be appropriately determined depending on the liquid supply target T. The liquid may be, for example, water, pure water, etc. In this embodiment, as an example, it is assumed that the liquid supply device 1 is used as a cleaning system. When pure water is used as the liquid in such a cleaning system, the liquid supply target T can be cleaned while suppressing adhesion of impurities to the liquid supply target T during cleaning. When the liquid supply target T is a precision machined product such as a semiconductor wafer, and this is cleaned by the liquid supply device 1 as a cleaning system, it is preferable to use pure water as the liquid, and it is more preferable to use ultrapure water.

As described above, the liquid supply device 1 according to this embodiment is configured as a discharge-type liquid supply device, so the liquid in the tank 2 gradually decreases as the liquid is discharged. For this reason, the liquid supply device 1 is equipped with a replenishing unit 2A that appropriately replenishes liquid in the tank 2. The replenishing unit 2A is connected to a liquid source, such as another tank, and appropriately replenishes liquid from the liquid source into the tank 2.

The pump 3 is a non-positive displacement pump, and is configured so that its rotation speed can be freely adjusted. The rotation speed of the pump 3 is controlled by the controller 20. More specifically, in this embodiment, as an example, the propeller of the pump 3 is rotated by an AC motor or a brushless motor, and the controller 20 controls the rotation speed of the AC motor or brushless motor via an inverter. This controls the rotation speed of the pump 3. Note that in this embodiment, during normal operation of the liquid supply device 1, the controller 20 rotates the pump 3 at a constant rotation speed.

The liquid supply device 1 according to this embodiment also includes a branch flow path 10 that branches off midway through the main flow path 4 and is connected to the tank 2. More specifically, the branch flow path 10 branches off from a portion of the main flow path 4 downstream of the heater 7B. This branch flow path 10 is provided to bypass a portion or all of the liquid flowing through the main flow path 4 to the tank 2 without sending it to the liquid supply target T, and an adjustment valve 11 is provided midway through the branch flow path 10. The adjustment valve 11 adjusts the flow rate of the liquid flowing through the branch flow path 10 from the main flow path 4 toward the tank 2, and is controlled by the controller 20.

The liquid supply device 1 according to this embodiment further includes an escape flow path 12 that branches off from the upstream portion of the control valve 11 in the branch flow path 10 and is connected to the tank 2, and a relief valve 13 that is provided in the escape flow path 12 and opens when the pressure on the upstream side exceeds a predetermined pressure. In more detail, in this embodiment, the escape flow path 12 branches off into two branches, and a relief valve 13 is provided at each of these branched portions.

The branch flow path 10, the adjustment valve 11, the escape flow path 12, and the relief valve 13 are provided to restore the pressure of the liquid to the state before the pressure fluctuation when the pressure of the liquid flowing through the main flow path 4 fluctuates. In detail, when the pressure of the liquid flowing through the main flow path 4 fluctuates, the opening of the adjustment valve 11 is adjusted and/or the relief valve 13 is opened, thereby restoring the pressure of the liquid to the state before the pressure fluctuation. More specifically, the adjustment valve 11 can mitigate the pressure fluctuation of the liquid by adjusting the opening when the pressure of the liquid flowing through the main flow path 4 increases and decreases. On the other hand, the relief valve 13 can mitigate the pressure increase by opening when the pressure of the liquid flowing through the main flow path 4 increases.

The control valve 11 is a proportional two-way valve, and in this embodiment, as an example, has a stepping motor 11M as an actuator that drives the valve body. The control valve 11 adjusts the position of the valve body (not shown) by the stepping motor 11M, changes the opening depending on the position of the valve body, and adjusts the flow rate of liquid flowing through the branch flow path 10 from the main flow path 4 toward the tank 2.

When the pressure of the liquid flowing through the main flow path 4 increases, the adjustment valve 11 can be opened wider to increase the flow rate of the liquid flowing through the branch flow path 10 from the main flow path 4 toward the tank 2, thereby lowering the pressure of the liquid flowing through the main flow path 4. On the other hand, when the pressure of the liquid flowing through the main flow path 4 decreases, the adjustment valve 11 can be opened narrower to decrease the flow rate of the liquid flowing through the branch flow path 10 from the main flow path 4 toward the tank 2, thereby raising the pressure of the liquid flowing through the main flow path 4.

The relief valve 13 is configured to press the valve body against the valve seat by a biasing member such as a spring, and the valve body separates from the valve seat when the upstream pressure exceeds a predetermined pressure. The relief valve 13 opens, for example, when the pressure of the liquid flowing through the main flow path 4 increases suddenly, thereby instantly reducing the pressure of the liquid flowing through the main flow path 4. In this embodiment, the biasing force of the biasing member is adjustable, and the value of the predetermined pressure at which the relief valve 13 opens can be adjusted.

The controller 20 may be configured, for example, as a computer having a CPU, ROM, etc. In this case, the controller 20 performs various processes according to a program stored in the ROM. Note that the controller 20 may also be configured as other processors or electrical circuits (for example, an FPGA (Field Programmable Gate Alley), etc.).

The controller 20 is electrically connected to the pump 3 and the control valve 11, and is also electrically connected to a pressure sensor 14. The pressure sensor 14 detects the pressure of the liquid flowing through the portion of the main flow path 4 upstream of the connection position of the branch flow path 10, more specifically, the portion of the temperature regulator 7 upstream of the cooler 7A. In other words, the pressure sensor 14 detects the pressure of the liquid that is sent out from the pump 3 and before its temperature is adjusted by the temperature regulator 7.

When the liquid supply device 1 is in normal operation, the controller 20 in this embodiment rotates the pump 3 at a "predetermined rotation speed" and controls the opening of the adjustment valve 11 so that the detection value of the pressure sensor 14 becomes the set target pressure. Note that normal operation refers to operation when liquid is supplied to the liquid supply target T, excluding when the liquid supply device 1 is started up and stopped. The target pressure is a value input to the controller 20 by a user operation.

The opening of the regulator valve 11 is controlled by feedback control based on the difference between the detection value of the pressure sensor 14 and the target pressure. This feedback control is performed continuously, and more specifically, for example, every sampling period of the pressure sensor 14.

In this embodiment, when the control valve 11 is set to an intermediate opening between fully open and fully closed (e.g., an opening between 5% and 40%) and all nozzles 6 are fully closed (in other words, outflow from the main flow path 4 is blocked) so that all of the fluid discharged by the pump 3 is bypassed from the branch flow path 10 to the tank 2, the rotation speed of the pump 3 that satisfies the following conditions is set as the "predetermined rotation speed": the flow rate of the liquid discharged by the pump 3 is greater than the maximum required flow rate of the liquid to be supplied to the liquid supply target T (e.g., 1.1 times or more the maximum required flow rate), and the pressure of the liquid discharged by the pump 3 at this time is greater than the minimum required pressure of the liquid to be supplied to the liquid supply target T (e.g., 1.2 times or more the minimum required pressure).

Then, the pump 3 is rotated at the predetermined rotation speed set as described above, and the pressure of the liquid in a state in which all of the fluid discharged by the pump 3 is bypassed from the branch flow path 10 to the tank 2 is set as the target pressure. Furthermore, this target pressure is also set as the predetermined pressure when the relief valve 13 opens.

Note that the settings of the rotation speed and target pressure of the pump 3 as described above are one example when the required specifications (specifically, the required pressure) of the liquid to be supplied to the liquid supply target T are constant, and such settings do not limit the present invention.

Figure 2 is a graph illustrating an example of the operation of the liquid supplying device 1. In the operation example shown in Figure 2, the liquid supplying device 1 operates as follows.

First, liquid is discharged from the nozzle 6 at 5 L/min for 300 seconds (section In in the figure).
Next, liquid is discharged from the nozzle 6 at 10 L/min for 600 seconds (starting at I in the figure).
Next, liquid is discharged from the nozzle 6 at 30 L/min for 600 seconds (starting at II in the figure).
Next, liquid is discharged from nozzle 6 at 10 L/min for 600 seconds (starting at III in the figure).
Thereafter, the liquid is ejected from the nozzle 6 at 30 L/min for 90 seconds, and then the liquid is ejected from the nozzle 6 at 10 L/min for 5 seconds. This operation is repeated multiple times (starting at IV in the figure).

In the above-described operation, when the flow rate of the liquid ejected by the nozzle 6 is changed, the pressure of the liquid in the main flow path 4 fluctuates. At this time, the liquid supply device 1 operates to return the pressure of the liquid to the state before the fluctuation, specifically to the target pressure, by adjusting the opening of the adjustment valve 11 and/or opening the relief valve 13.

In the operation shown in FIG. 2, when the control valve 11 is set to an intermediate opening between fully open and fully closed, and all of the nozzles 6 are fully closed, and all of the fluid discharged by the pump 3 is bypassed from the branch flow path 10 to the tank 2, the rotation speed of the pump 3 is set to a rotation speed (predetermined rotation speed) at which the pump 3 discharges liquid at a flow rate of 35 L/min. The pressure Ps of the liquid flowing through the main flow path 4 at this time is set as the target pressure.

Figures 3 and 4 each show a graph illustrating an example of the pressure adjustment operation of the liquid supply device 1 performed during the operation shown in Figure 2. Figure 5 shows a graph illustrating an example of the pressure adjustment operation of the liquid supply device 1 performed during the operation shown in Figure 2 and the change in the liquid flow rate during this operation. Details of the operation shown in Figure 2 and the state of pressure adjustment during this operation will be described below with reference to Figures 2 to 5.

In section In in FIG. 2, liquid is ejected from nozzle 6 at 5 L/min for 300 seconds. In this operation, liquid is bypassed from branch flow path 10 to tank 2 at 30 L/min. At this time, the pressure of the liquid flowing through main flow path 4 is roughly maintained at target pressure Ps. If pressure fluctuations occur in the liquid, adjustment valve 11 may operate, but since no large pressure fluctuations occur in section In, adjustment valve 11 does not operate significantly.

In FIG. 3 to FIG. 5, a state or section corresponding to the section In is indicated by the same reference symbol In.
The horizontal axis of Fig. 3 indicates the flow rate of liquid (pump discharge flow rate (L/min)) sent by the pump 3 to the main flow path 4, and the vertical axis indicates the pressure of the liquid (pump discharge pressure (MPa)) sent by the pump 3 to the main flow path 4. The state In shown in Fig. 3 indicates that the pump discharge flow rate is 35 L/min and the pump discharge pressure is maintained at Ps.
The horizontal axis of Figure 4 indicates the flow rate of liquid bypassed from the branch flow path 10 to the tank 2 (tank relief flow rate (L/min)), and the vertical axis indicates the pressure of the liquid sent by the pump 3 to the main flow path 4 (pump discharge pressure (MPa)). The state of In shown in Figure 4 indicates that the tank relief flow rate is 30 L/min and the pump discharge pressure is maintained at Ps. In addition, "Supply: 5 (L/min)" is shown under the dotted circle indicating In, which indicates the flow rate of liquid discharged by the nozzle 6. The tank relief flow rate and the flow rate of liquid discharged by the nozzle 6 are added together to obtain a pump discharge flow rate of 35 L/min.
5, the horizontal axis indicates time (seconds), and the vertical axis indicates the flow rate of the liquid (L/min) and the pressure of the liquid sent by the pump 3 to the main flow path 4 (pump discharge pressure (MPa)). In the graph of FIG. 5, the symbol X is a broken line indicating the change in the tank relief flow rate, the symbol Y is a broken line indicating the change in the flow rate of the liquid supplied from the nozzle 6, and the symbol Z is a broken line indicating the change in the pump discharge pressure.

After the above-mentioned operation of section In, the operation of "discharging liquid from nozzle 6 at 10 L/min for 600 seconds" is performed, which starts at the timing of symbol I in FIG. 2. In this operation, the flow rate of the liquid supplied from nozzle 6 is suddenly switched from 5 L/min to 10 L/min. Due to this, immediately after the switch, the pump discharge flow rate sent from pump 3 to main flow path 4 becomes greater than 35 L/min, and the pump discharge pressure becomes smaller than the target pressure Ps. This state is shown by symbol I in FIG. 3 and FIG. 4. In FIG. 3, in the state shown by symbol I, the pump discharge flow rate exceeds 35 L/min, and the pump discharge pressure is smaller than the target pressure Ps. In FIG. 4, in the state shown by symbol I, the flow rate of the liquid supplied from nozzle 6 is 10 L/min, while the tank relief flow rate exceeds 25 L/min, and the pump discharge flow rate obtained by adding these exceeds 35 L/min. In addition, the pump discharge pressure is lower than the target pressure Ps.

When the pump discharge flow rate sent from the pump 3 to the main flow path 4 exceeds 35 L/min and the pump discharge pressure is lower than the target pressure Ps, the liquid supply device 1 adjusts the adjustment valve 11 so that the opening of the adjustment valve 11 is reduced, and the detection value of the pressure sensor 14 approaches the target pressure. This increases the pressure drop of the liquid in the main flow path 4 toward the target pressure. The flow of pressure adjustment by the operation of the adjustment valve 11 is shown by the solid arrow in Figure 3, and by the arrow from the state indicated by symbol I to state A in Figure 4. Also, Figure 5 shows that the pump discharge pressure is decreasing at the point in time indicated by symbol I, but then converges to the target pressure Ps.

After that, the operation of "discharging liquid from nozzle 6 at 30 L/min for 600 seconds" is performed, which starts at the timing of symbol II in FIG. 2. In this operation, the flow rate of the liquid supplied from nozzle 6 is suddenly switched from 10 L/min to 30 L/min. Due to this, immediately after the switch, the pump discharge flow rate sent from pump 3 to main flow path 4 becomes greater than 35 L/min, and the pump discharge pressure becomes smaller than the target pressure Ps. This state is shown by symbol II in FIG. 3 and FIG. 4. In FIG. 3, in the state shown by symbol II, the pump discharge flow rate greatly exceeds 35 L/min, and the pump discharge pressure is significantly smaller than the target pressure Ps. In FIG. 4, in the state shown by symbol II, the flow rate of the liquid supplied from nozzle 6 is 30 L/min, while the tank relief flow rate exceeds 5 L/min, and the pump discharge flow rate obtained by adding these exceeds 35 L/min. In addition, the pump discharge pressure becomes smaller than the target pressure Ps.

Even in this case, the liquid supply device 1 adjusts the adjustment valve 11 so that its opening becomes smaller, and the detection value of the pressure sensor 14 approaches the target pressure. This causes the pressure drop of the liquid in the main flow path 4 to increase toward the target pressure. The flow of pressure adjustment by the operation of the adjustment valve 11 is shown by the dashed arrow in Figure 3, and by the arrow pointing from the state indicated by symbol II to state B in Figure 4. Also, Figure 5 shows that the pump discharge pressure drops significantly at the point in time indicated by symbol II, but then converges to the target pressure Ps.

After this, the operation of "discharging liquid from nozzle 6 at 10 L/min for 600 seconds" is performed, which starts at the timing of symbol III in Figure 2. In this operation, the flow rate of the liquid supplied from nozzle 6 is suddenly switched from 30 L/min to 10 L/min. Due to this, immediately after the switch, the pump discharge flow rate sent from pump 3 to main flow path 4 becomes smaller than 35 L/min, and the pump discharge pressure becomes larger than the target pressure Ps. This state is shown by symbol III in Figures 3 and 4. In Figure 3, in the state shown by symbol III, the pump discharge flow rate becomes significantly smaller than 35 L/min, and the pump discharge pressure becomes significantly larger than the target pressure Ps. In Figure 4, in the state shown by symbol III, the flow rate of the liquid supplied from nozzle 6 is 10 L/min, while the tank relief flow rate becomes significantly smaller than 25 L/min, and the pump discharge flow rate obtained by adding these becomes significantly smaller than 35 L/min. In addition, the pump discharge pressure is significantly higher than the target pressure Ps.

In such a case, the liquid supply device 1 adjusts the adjustment valve 11 so that its opening is increased, and the relief valve 13 opens, bringing the detection value of the pressure sensor 14 closer to the target pressure. This reduces the increase in liquid pressure in the main flow path 4 toward the target pressure. The flow of pressure adjustment by such operation of the adjustment valve 11 is shown by the two-dot chain arrow in Figure 3, and by the arrow pointing from the state indicated by symbol III to state A in Figure 4. Also, Figure 5 shows that the pump discharge pressure rises significantly at the point in time indicated by symbol III, but then converges to the target pressure Ps.

Then, in the operation of "ejecting liquid from nozzle 6 at 30 L/min for 90 seconds, followed by ejecting liquid from nozzle 6 at 10 L/min for 5 seconds, repeated multiple times," which starts at timing IV in FIG. 2, the flow rate of liquid from nozzle 6 is repeatedly increased or decreased significantly, and even in this case, if the liquid pressure decreases, the opening of adjustment valve 11 decreases, and if the liquid pressure increases, the opening of adjustment valve 11 increases and relief valve 13 opens appropriately. This reduces fluctuations in the liquid pressure from the target pressure.

As described above, in the liquid supply device 1, when the pressure of the liquid flowing through the main flow path 4 fluctuates due to switching of the flow rate of the liquid supplied from the nozzle 6 to the liquid supply target T, the opening of the adjustment valve 11 is controlled to adjust the flow rate of the liquid returning from the branch flow path 10, thereby controlling the pressure of the liquid sent out from the pump 3 toward the target pressure. This makes it possible to mitigate pressure fluctuations of the liquid in the main flow path 4. Specifically, when the detection value of the pressure sensor 14 becomes larger than the target pressure, the opening of the adjustment valve 11 is increased, and when the detection value becomes smaller than the target pressure, the opening of the adjustment valve 11 is decreased, thereby controlling toward the target pressure, and fluctuations in the pressure of the liquid in the main flow path 4 from the target pressure can be mitigated. In such pressure adjustment by adjusting the opening of the adjustment valve 11, the pressure of the liquid is adjusted with good responsiveness and is not greatly disturbed. Therefore, disturbances from the desired state of the liquid to be supplied can be effectively suppressed, and specifically, significant fluctuations in the pressure of the liquid from the desired pressure can be suppressed.

The liquid supply device 1 according to this embodiment further includes an escape flow path 12 that branches off from the upstream portion of the control valve 11 in the branch flow path 10 and is connected to the tank 2, and a relief valve 13 that is provided in the escape flow path 12 and opens when the pressure upstream of the escape flow path exceeds a predetermined pressure. This improves the control responsiveness to the target pressure when the pressure of the liquid flowing through the main flow path 4 increases suddenly. In other words, when the pressure of the liquid flowing through the main flow path 4 increases suddenly, the relief valve 13 opens and the stagnation of the liquid is quickly eliminated, so that the pressure of the liquid immediately approaches the target pressure. This improves the control responsiveness to the target pressure.

The liquid supply device 1 according to this embodiment further includes a temperature regulator 7 that regulates the temperature of the liquid flowing through the portion of the main flow path 4 upstream of the connection position of the branch flow path 10, and the pressure sensor 14 detects the pressure of the liquid before its temperature is regulated by the temperature regulator 7. In this configuration, the function of the adjustment valve 11 as described above suppresses fluctuations in the flow rate of the liquid flowing into the temperature regulator 7, thereby preventing the flow rate and temperature of the liquid whose temperature is regulated by the temperature regulator 7 from being disturbed from the desired state. This makes it possible to supply liquid at the desired pressure while suppressing a decrease in the accuracy of temperature regulation when regulating the temperature of the liquid supply target T by liquid.

Second Embodiment
Next, a liquid supplying apparatus according to a second embodiment will be described. Fig. 6 shows a schematic configuration of the liquid supplying apparatus according to the second embodiment. The same components in this embodiment as those in the first embodiment are indicated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 6, the second embodiment does not include the escape flow path 12 and relief valve 13 described in the first embodiment. The other components are the same as those in the first embodiment. In this embodiment, when the pressure fluctuation of the liquid is not large, the device configuration can be simplified while ensuring the desired pressure adjustment function.

Third Embodiment
Next, a liquid supplying device according to a third embodiment will be described. Fig. 7 shows a schematic configuration of the liquid supplying device according to the third embodiment. The same components in this embodiment as those in the first and second embodiments are indicated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 7, the liquid supply device according to the third embodiment is configured as a circulation type liquid supply device in which the liquid discharged from the main flow path 4 is returned to the tank 2 via the liquid supply target T. In this type of embodiment, disturbances in the flow state of the liquid passing through the liquid supply target T can be suppressed.

Although each embodiment has been described above, the present invention is not limited to the above-mentioned embodiments, and various modifications can be made to each of the above-mentioned embodiments. Such modified forms are also included in the scope of the present invention.

1...liquid supply device, 2...tank, 2A...supply section, 3...pump, 4...main flow path, 5...downstream distribution flow path, 6...nozzle, 7...temperature regulator, 7A...cooler, 7B...heater, 10...branch flow path, 11...regulating valve, 11M...stepping motor, 12...relief flow path, 13...relief valve, 14...pressure sensor, 20...controller

Claims (5)

a main flow path connected to a pump that sucks and delivers liquid from a tank, and through which the liquid delivered from the pump flows and is delivered to a liquid delivery target side;
a branch flow path that branches off midway through the main flow path and is connected to the tank;
an adjustment valve provided in the branch flow path to adjust a flow rate of the liquid flowing through the branch flow path from the main flow path toward the tank;
A controller for controlling the pump and the regulator valve;
a relief flow path that branches off from a portion of the branch flow path upstream of the adjustment valve and is connected to the tank;
a relief valve that is provided in the relief flow path and opens when the pressure on the upstream side of the relief flow path exceeds a predetermined pressure,
The controller controls the opening of the adjustment valve so that the detection value of a pressure sensor that detects the pressure of the liquid flowing through the portion of the main flow path upstream of the connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed. a main flow path connected to a pump that sucks and delivers liquid from a tank, and through which the liquid delivered from the pump flows and is delivered to a liquid delivery target side;
a branch flow path that branches off midway through the main flow path and is connected to the tank;
an adjustment valve provided in the branch flow path to adjust a flow rate of the liquid flowing through the branch flow path from the main flow path toward the tank;
A controller for controlling the pump and the regulator valve;
a temperature regulator that regulates a temperature of the liquid flowing through a portion of the main flow path upstream of a connection position of the branch flow path,
the controller controls an opening of the adjustment valve so that a detection value of a pressure sensor detecting a pressure of the liquid flowing through a portion of the main flow path upstream of a connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed;
The pressure sensor detects the pressure of the liquid before its temperature is adjusted by the temperature adjuster. a main flow path connected to a pump that sucks and delivers liquid from a tank, and through which the liquid delivered from the pump flows and is delivered to a liquid delivery target side;
a branch flow path that branches off midway through the main flow path and is connected to the tank;
an adjustment valve provided in the branch flow path to adjust a flow rate of the liquid flowing through the branch flow path from the main flow path toward the tank;
A controller for controlling the pump and the regulator valve;
one or more nozzles that receive the liquid delivered by the main flow path and eject it to the liquid supply target;
The liquid supply device is configured as a discharge type liquid supply device that discharges the liquid delivered by the main flow path to the liquid supply target,
The nozzle is capable of switching between discharging and blocking the liquid, and/or adjusting the flow rate during discharging,
The controller controls the opening of the adjustment valve so that the detection value of a pressure sensor that detects the pressure of the liquid flowing through the portion of the main flow path upstream of the connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed . a main flow path connected to a pump that sucks and delivers liquid from a tank, and through which the liquid delivered from the pump flows and is delivered to a liquid delivery target side;
a branch flow path that branches off midway through the main flow path and is connected to the tank;
an adjustment valve provided in the branch flow path to adjust a flow rate of the liquid flowing through the branch flow path from the main flow path toward the tank;
a controller for controlling the pump and the regulator valve;
a circulation type liquid supply device that returns the liquid discharged from the main flow path to the tank via the liquid supply target ,
The controller controls the opening of the adjustment valve so that the detection value of a pressure sensor that detects the pressure of the liquid flowing through the portion of the main flow path upstream of the connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed . a main flow path connected to a pump that sucks and delivers liquid from a tank, and through which the liquid delivered from the pump flows and is delivered to a liquid delivery target side;
One or more nozzles that receive the liquid delivered by the main flow path and eject it to the liquid supply target;
a branch flow path that branches off midway through the main flow path and is connected to the tank;
an adjustment valve provided in the branch flow path to adjust a flow rate of the liquid flowing through the branch flow path from the main flow path toward the tank;
a controller for controlling the pump and the regulator valve;
The cleaning system is configured as a discharge type cleaning system that discharges the liquid delivered by the main flow path to the liquid supply target,
The nozzle is capable of switching between discharging and blocking the liquid, and/or adjusting the flow rate during discharging,
the controller controls an opening of the adjustment valve so that a detection value of a pressure sensor detecting a pressure of the liquid flowing through a portion of the main flow path upstream of a connection position of the branch flow path becomes a set target pressure while rotating the pump at a predetermined rotation speed;
A cleaning system that performs cleaning by ejecting the liquid from the nozzle.