JP4809809B2 - Liquid supply system - Google Patents

Description

  The present invention relates to a liquid supply system for distributing and supplying a liquid such as a chemical used for manufacturing a semiconductor product or a chemical to a plurality of use points.

  In manufacturing plants for semiconductor products and chemicals, a system is used in which a liquid such as a chemical is pumped from a supply source such as a tank and circulated through a distribution line and distributed to a plurality of use points. The outline of the system will be described with reference to FIG.

  As shown in FIG. 12, a main supply line 72 is connected to the liquid tank 71, and the liquid in the liquid tank 71 is pumped up by a pump 73 and then circulates through the main supply line 72. A plurality of branch lines 74 are connected to the main supply line 72, and an open / close valve 75 and a variable throttle 76 are provided for each branch line 74. In such a configuration, a liquid is supplied to a predetermined use point by opening one of the on-off valves 75 of each branch line 74. Further, a pressure gauge 77 for detecting the liquid pressure and a relief valve 78 for releasing the liquid pressure are provided on the downstream side of each branch line 74 in the main supply line 72.

  In the system having the above-described configuration, it is possible to supply liquid to a large number of use points with a configuration having a single liquid pumping system. At this time, the liquid can be distributed and supplied to any number of use points at the same time within the range of the set number of branch lines.

  However, in the above-described conventional system, when each branch line 74 is arbitrarily opened, the total flow rate of the liquid flowing out through each branch line 74 changes accordingly. Therefore, the liquid pressure flowing through the main supply line 72 varies, and as a result, the liquid flow rate in each branch line varies. As a result, the liquid flow rate supplied to each use point varies.

As a countermeasure, it is conceivable to install a pressure sensor, a pressure regulating valve (regulator) or the like for each branch line 74 and individually adjust the pressure. However, in such a case, the configuration becomes complicated, and problems remain in installation space and cost. Incidentally, Patent Document 1 and the like are known as a technique for stabilizing the liquid discharge flow rate by feedback control.
JP-A-7-232113

  The main object of the present invention is to appropriately control a liquid pressure as desired while avoiding complication of the configuration in a liquid supply system that enables the distribution and supply of liquid to a plurality of use points. is there.

  Hereinafter, effective means for solving the above-described problems will be described while showing effects and the like as necessary. In the following, in order to facilitate understanding, a corresponding configuration example in the embodiment of the invention is appropriately shown in parentheses, etc., but is not limited to the specific configuration shown in parentheses.

Means 1. A liquid passage (main supply line 12) for circulating liquid;
A pumping means (pump 13) provided in the middle of the liquid passage for pumping the liquid;
A plurality of branch passages (branch lines LN1 to LNn) provided by branching from the liquid passage;
A pressure adjusting actuator (relief valve 31, electropneumatic regulator 32, etc.) provided in the middle of the liquid passage for adjusting the liquid pressure in the liquid passage;
A liquid supply system that individually opens or closes the plurality of branch passages and distributes the liquid from the liquid passage through the opened branch passages.
A control amount calculation means (controller 35) for calculating a control amount of the pressure adjusting actuator corresponding to a change in the flow rate of the branch passage when the branch passage is opened or closed;
Actuator control means (controller 35) for controlling the drive of the pressure adjusting actuator based on the actuator control amount calculated by the control amount calculation means in synchronization with opening and closing of the branch passage;
A liquid supply system comprising:

  The liquid supply system of means 1 is provided with a plurality of branch passages branched from the liquid passage, and the liquid is distributed and supplied to a plurality of liquid supply destinations (use points) by the branch passages. In such a configuration, it is considered that when the flow rate of the liquid flowing through the open branch passage is changed as the number of open branch passages is changed, pressure fluctuation may occur in the liquid passage. In this regard, in the present invention, when each branch passage is required to be opened or closed as described above, the actuator control amount corresponding to the flow rate change amount of the branch passage accompanying the opening or closing is calculated, and the branch passage is opened or closed. Even if the flow rate of the branch passage changes due to the change in the number of opening of the branch passage by controlling the driving of the pressure adjusting actuator based on the actuator control amount in synchronization with The pressure fluctuation in the liquid passage caused by the above can be suppressed. Further, in this configuration, it is not necessary to install a pressure sensor, a pressure regulating valve (regulator), or the like for each branch passage, so that the configuration can be simplified. As described above, the liquid pressure can be appropriately controlled as desired while avoiding complication of the configuration. Thereby, the flow rate of the liquid flowing through each branch passage is stabilized.

Mean 2. Control amount data defining the relationship between the number of the branch passages that are simultaneously opened and closed and the actuator control amount is stored in a storage device (memory 35b),
The liquid supply system according to claim 1, wherein the control amount calculation means calculates the actuator control amount with reference to the control amount data when the branch passage is opened and closed in response to the request.

  If the number of branch passages that are simultaneously opened / closed according to the request is different, the flow rate change amount of the branch passages accompanying the opening / closing is changed, and the state of pressure fluctuation in the liquid passage is also changed. In this regard, by defining the control amount data as described above and calculating the actuator control amount with reference to the control amount data, any number of branch passages opened and closed at the same time, The pressure fluctuation in the liquid passage when the branch passage is opened and closed can be suitably suppressed.

  In addition, it is thought that the structure which makes the parameter the number of the branch passages opened and closed simultaneously as mentioned above becomes an effective means when those passage cross-sectional areas are the same about several branch passages.

Means 3. For each of the plurality of branch passages, passage-specific data defining the actuator control amount corresponding to the flow rate change accompanying opening and closing for each branch passage is stored in a storage device (memory 35b),
The liquid supply system according to claim 1, wherein the control amount calculation means calculates the actuator control amount with reference to the data for each passage when the branch passage is opened and closed in response to the request.

  It is also conceivable that the amount of change in flow rate associated with opening and closing of a plurality of branch passages differs for each passage. In this regard, by defining the path-specific data as described above and calculating the actuator control amount with reference to the path-specific data, even if the flow rate is different for each branch path, The pressure fluctuation in the liquid passage during opening and closing can be suitably suppressed.

  When a plurality of branch passages are opened and closed simultaneously, the final actuator control amount may be calculated by adding the actuator control amounts for the branch passages opened and closed simultaneously. For example, the actuator control amount corresponding to the flow rate change accompanying opening and closing of the first branch passage is β1, and the actuator control amount corresponding to the flow rate change accompanying opening and closing of the second branch passage is β2, and the first and second branches When the passages are simultaneously opened (or closed), the actuator control amount is calculated as “β1 + β2”.

Means 4. Pressure detecting means (pressure sensor 33) for detecting the liquid pressure in the liquid passage;
Feedback control means (controller 35) for feedback-controlling the control amount of the pressure adjusting actuator so that the liquid pressure detected by the pressure detection means matches a target value;
The liquid supply system according to any one of means 1 to 3, further comprising:

  As described above, it is considered that the pressure fluctuation in the liquid passage is greatly suppressed by controlling the driving of the pressure adjusting actuator in synchronization with the opening and closing of the branch passage upon request. It is assumed that pressure fluctuations occur in the liquid passage. In this regard, by executing the feedback control in combination, even if the pressure fluctuation temporarily occurs, the pressure fluctuation can be quickly eliminated.

Means 5. Open / close command means (controller 35) for commanding to open / close at least one of the plurality of branch passages;
After the command by the opening / closing command means, feedback control by the feedback control means is executed in a state where control of the pressure adjusting actuator by the actuator control means is stopped, and an actual control amount (feedback control amount) obtained by the feedback control And a control amount storage means (controller 35) for storing in correspondence with each opening / closing command of the branch passage,
5. The liquid supply system according to claim 4, wherein the control amount calculation means calculates an actuator control amount each time using the actual control amount stored by the control amount storage means.

  According to the means 5, by feedback control of the liquid pressure in the liquid passage in a state where the control by the actuator control means (that is, drive control of the pressure adjusting actuator performed in synchronization with opening and closing of the branch passage) is stopped, It is possible to accurately grasp how much the actuator control amount (actual control amount) is actually required by opening and closing the branch passage upon request. That is, as a result, teaching processing can be performed appropriately, and good teaching data can be obtained for the actuator control amount (actual control amount). When the system is in operation, the pressure adjustment actuator can be controlled with the optimum actuator control amount by using the teaching data. In this case, even if the flow rate change amount at the time of opening and closing each branch passage changes due to a change over time or the like, it is possible to realize optimal control in accordance with the change.

  Teaching data acquisition may be performed at the time of system startup, or may be repeatedly performed periodically or irregularly after system startup. If teaching data is already stored, the previous teaching data is updated with new teaching data.

  Means 6. 6. The liquid supply system according to claim 5, wherein the opening / closing command means sequentially commands all patterns corresponding to the number of branch paths that can be simultaneously opened / closed for the plurality of branch paths.

  This makes it possible to acquire actual control amounts (teaching data) for all patterns corresponding to the number of branch paths that can be opened and closed simultaneously.

  Mean 7 6. The liquid supply system according to claim 5, wherein the opening / closing command means sequentially commands the branch passages to be opened or closed one by one for the plurality of branch passages.

  Thereby, the actual control amount (teaching data) can be acquired individually for all the branch passages that are opened and closed in response to the request. In this case, even if the liquid flow rate at the time of opening is different for each branch passage, or even if there is an individual difference, the actual control amount (teaching data) can be suitably acquired by dealing with it.

Means 8. Pressure change detection means (controller 35) for detecting a pressure change in the liquid passage after the actuator is driven by the actuator control means;
Timing control means (controller 35) for changing the drive timing of the actuator for pressure adjustment by the actuator control means based on the pressure change detected by the pressure change detection means;
The liquid supply system according to any one of means 1 to 7, further comprising:

  Here, if the driving of the pressure adjusting actuator is controlled in synchronization with the opening and closing of the branch passage as described above, it is possible to sufficiently suppress the pressure fluctuation in the liquid passage. If it is too early or too late, pressure fluctuations are considered to occur temporarily. This is considered to be caused by an operation delay of the pressure adjusting actuator. In this respect, according to the means 8, since the timing for driving the pressure adjusting actuator is appropriately changed, even if a temporary pressure fluctuation occurs immediately after the opening and closing of the branch passage, the pressure fluctuation is caused at the next driving of the actuator. Can be suppressed.

  Means 9. The timing control means advances the actuator drive timing when the pressure change detecting means detects a decreasing pressure change when the branch passage opening is requested, and the pressure change detecting means is also used when the opening request is requested. 9. The liquid supply system according to claim 8, wherein the actuator drive timing is delayed when an increase in pressure change is detected.

  According to the above configuration, when the opening of the branch passage is requested, the actuator drive timing is advanced, so that the pressure adjustment by the actuator (here, the pressure adjustment that suppresses the decrease in the liquid pressure) can be applied quickly. Thereby, the pressure change on the decreasing side in the liquid passage can be suppressed. Similarly, when the release request is made, the actuator drive timing is delayed, so that the pressure adjustment by the actuator (here, the pressure adjustment for suppressing the increase of the liquid pressure) can be applied quickly. Thereby, the pressure change on the increase side in the liquid passage can be suppressed.

  Incidentally, the following configuration is applied when driving the pressure adjusting actuator in response to a request for closing the branch passage. That is, when an increase in pressure change is detected by the pressure change detecting means when the branch passage is closed, the actuator drive timing is advanced, and when the close request is received, the pressure change detecting means reduces the pressure on the decreasing side. If a change is detected, the actuator drive timing is delayed. Thereby, the pressure fluctuation in the liquid passage can be more appropriately suppressed when the branch passage is closed.

Means 10. Pressure change detection means (controller 35) for detecting a pressure change in the liquid passage after the actuator is driven by the actuator control means;
Control amount correction means (controller 35) for correcting the actuator control amount from the next time on by the actuator control means based on the pressure change detected by the pressure change detection means;
The liquid supply system according to any one of means 1 to 7, further comprising:

  As described above, when the pressure fluctuation is temporarily generated when the drive of the pressure adjusting actuator is controlled in synchronization with the opening and closing of the branch passage, one reason is considered that the actuator control amount is too large or too small. . In this respect, according to the means 10, since the control amount of the pressure adjusting actuator is appropriately changed, even if a temporary pressure fluctuation occurs immediately after the opening and closing of the branch passage, the pressure fluctuation is suppressed at the next and subsequent actuator driving. can do.

Means 11. As the pressure adjusting actuator, a pilot-operated relief valve (relief valve 31) provided downstream of the branch point of each branch passage in the liquid passage, and a pilot for adjusting the pilot pressure acting on the relief valve Pressure adjusting means (electropneumatic regulator 32),
The control amount calculating means calculates a control amount corresponding to a pilot pressure for eliminating a pressure change accompanying opening and closing of the branch passage as the actuator control amount. The liquid supply system as described.

  According to the means 11, the degree of pressure release (pressure release) by the relief valve is changed by controlling the pilot pressure by the pilot pressure adjusting means, and accordingly, the primary pressure of the relief valve (that is, upstream side of the relief valve) Liquid pressure) can be properly controlled. Therefore, the liquid pressure and flow rate in each branch passage are stabilized.

  In the configuration in which the pressure control is performed on the downstream side of the branch point of each branch passage as described above, even if particles (dust etc.) are generated by the relief valve, the particles do not flow into each branch passage. Therefore, it can be said that it is advantageous also in maintaining the cleanliness of the liquid.

Means 12. As the pressure adjusting actuator, a pilot-actuated pressure adjusting valve (pressure regulator 61) provided upstream of the branch point of each branch passage in the liquid passage, and a pilot pressure acting on the pressure adjusting valve are adjusted. Pilot pressure adjusting means (electropneumatic regulator 62) for
The control amount calculating means calculates a control amount corresponding to a pilot pressure for eliminating a pressure change accompanying opening and closing of the branch passage as the actuator control amount. The liquid supply system as described.

  According to the means 12, the degree of pressure adjustment by the pressure adjusting valve is changed by controlling the pilot pressure by the pilot pressure adjusting means, and accordingly, the secondary pressure of the pressure adjusting valve (that is, downstream side of the pressure adjusting valve) Liquid pressure) can be properly controlled. Therefore, the liquid pressure and flow rate in each branch passage are stabilized.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. An outline of the liquid supply system in the present embodiment will be described with reference to FIG. The liquid supply system of FIG. 1 assumes, as an example, a system for distributing and supplying a cleaning liquid to a plurality of cleaning apparatuses (use points) when manufacturing semiconductor products, chemicals, and the like.

  In FIG. 1, the liquid tank 11 stores a cleaning liquid as a liquid. A main supply line 12 made of piping or the like is connected to the liquid tank 11, and the main supply line 12 is provided with a pump 13 that pumps up the liquid in the liquid tank 11 and discharges (pressure-feeds) the liquid at a predetermined pressure downstream. It has been. The main supply line 12 circulates liquid using the liquid tank 11 as a liquid supply source, and the line start end and the line end are both connected to the liquid tank 11. In the present embodiment, the main supply line 12 corresponds to a “liquid passage”, and the pump 13 corresponds to a “pressure feeding unit”.

  The main supply line 12 is connected to a plurality of branch lines LN1, LN2, LN3,..., LNn for distributing and supplying the liquid flowing through the line 12 to a plurality of cleaning devices (for example, n = 10). The branch lines LN1 to LNn are constituted by a plurality of pipes having the same passage opening area, and this corresponds to a “branch passage”. Each branch line LN1 to LNn is provided with an open / close valve 21 that opens or closes the branch line to permit or prohibit passage of liquid and a variable throttle 22 for adjusting the flow rate. The on-off valves 21 of the branch lines LN1 to LNn are constituted by air operated valves that are opened and closed by air pressure. Depending on the energization state of the electromagnetic valves 23 provided for the on-off valves 21, the on-off valves 21 are provided. The acting air pressure is adjusted, and the on-off valve 21 is opened and closed accordingly. When any of the on-off valves 21 of the branch lines LN1 to LNn is opened, the liquid flows through the branch line corresponding to the open on-off valve 21.

  The opening / closing operation of each on-off valve 21 is controlled by the branch line control device 25. That is, the branch line control device 25 has control management data for determining which liquid supply destination (use point) to supply liquid (that is, which branch line to open) based on each work process or the like. Is stored, and the branch line control device 25 determines which open / close valve 21 is to be opened / closed based on the management data (that is, in which branch line the fluid is circulated). And according to the result of the judgment, an open / close drive signal is outputted to each electromagnetic valve 23, and each open / close valve 21 is selectively opened or closed.

  When each open / close valve 21 is opened or closed by the branch line control device 25, a branch line open / close signal indicating which open / close valve 21 (branch line) is opened or closed is a controller 35 of the pressure controller 30 described later. To be sent to. At this time, the branch line control device 25 outputs a branch line opening / closing signal to the controller 35 of the pressure control unit 30 simultaneously with outputting an opening / closing drive signal to the electromagnetic valve 23.

  Further, a pressure control unit 30 for controlling the liquid pressure in the present system is provided downstream of the branch points of the branch lines LN1 to LNn in the main supply line 12. The pressure control unit 30 includes a relief valve 31 provided on the main supply line 12, an electropneumatic regulator 32 that adjusts the pressure of operation air supplied to the relief valve 31, and a liquid pressure (relief valve 31) in the main supply line 12. A pressure sensor 33 for detecting a primary pressure) and a controller 35 formed of a microcomputer having a CPU 35a, a memory 35b, and the like. The relief valve 31 and the electropneumatic regulator 32 correspond to a pressure adjusting actuator.

  The relief valve 31 is a pilot-operated pressure regulating valve, and its configuration will be briefly described with reference to FIG. In the relief valve 31, a valve body 44 integrally having a diaphragm portion 43 is provided between a primary side passage 41 on the liquid inlet side and a secondary side passage 42 on the liquid outlet side. Displacement prevents or allows the liquid to flow through the primary side passage 41 and the secondary side passage 42. At this time, the liquid pressure in the primary side passage 41 (primary side pressure) acts on the diaphragm 43 to displace the valve body 44 to the open side, and the liquid in the primary side passage 41 flows out to the secondary side passage 42. To do.

  The relief valve 31 is provided with an operation air chamber 46 for introducing operation air from the outside. The valve body 44 has a pressure (operation air pressure) in the operation air chamber 46 opposite to the primary side pressure. Has come to work. This operating air pressure corresponds to the pilot pressure. The operation air chamber 46 communicates with an air inlet / outlet port 47, and the operation air pressure is variably adjusted by introducing the operation air supplied from the electropneumatic regulator 32 through the air inlet / outlet port 47.

  In this case, when the operating air pressure is changed to the increasing side, the opening degree of the valve body 44 is controlled to the closed side even if the liquid pressure (primary side pressure) in the primary side passage 41 is constant. As a result, the flow rate of the liquid flowing through the relief valve 31 is reduced, and the degree of pressure release (pressure release) by the relief valve 31 is reduced. In other words, by increasing the operating air pressure, the liquid pressure in the main supply line 12 can be controlled to the increasing side. When the operating air pressure is changed to the decreasing side, the opening degree of the valve body 44 is controlled to the open side even if the liquid pressure (primary side pressure) in the primary side passage 41 is constant. As a result, the flow rate of the liquid flowing through the relief valve 31 increases, and the degree of pressure release (pressure release) by the relief valve 31 increases. In other words, by reducing the operating air pressure, the liquid pressure in the main supply line 12 can be controlled to the decreasing side. In addition, as a structure of the relief valve 31, the electropneumatic regulator 32 can also be provided integrally.

  Returning to the description of FIG. 1, the pressure detection signal from the pressure sensor 33 is sequentially input to the controller 35 in the pressure control unit 30. The controller 35 adjusts the pressure of the operation air discharged from the electropneumatic regulator 32 based on the liquid pressure (actual pressure) calculated from the pressure detection signal. By adjusting the operating air pressure by the electropneumatic regulator 32, the liquid pressure in the main supply line 12 (primary side pressure of the relief valve 31) is controlled to each set pressure. At this time, the set pressure may be set by an external input by the operator, or may be set by a calculation process of the controller 35 so as to become an optimum value each time.

  The controller 35 also receives a branch line opening / closing signal from the branch line control device 25, and grasps the opening / closing state of each branch line based on the branch line opening / closing signal. For example, the presence / absence of a line open / close request for increasing or decreasing the number of branch lines is determined based on the branch line open / close signal.

  By the way, in the liquid supply system having the above-described configuration, pressure feedback control for converging the liquid pressure in the main supply line 12 to each set pressure (target value) is executed. More specifically, for example, a control command value for the electropneumatic regulator 32 is calculated based on the deviation between the set pressure and the actual pressure (measured pressure by the pressure sensor 31) using a control method such as PID and PI. Pressure control is performed by a signal output based on the control command value. By the above feedback control, even if the liquid pressure in the main supply line 12 changes due to the flow of liquid through any branch line LN1 to LNn, the original set pressure can be quickly restored thereafter.

  Here, in the above system, which one of the plurality of branch lines LN1 to LNn is opened is arbitrarily switched, and when the number of branch lines opened or increased, the liquid pressure in the main supply line 12 is increased. Variation occurs. Specifically, as shown in FIG. 3A, when the number of open lines increases by newly opening the branch line LNi, the liquid from the main supply line 12 is supplied to the branch line LNi by opening the branch line LNi. Flows in, the main line pressure (liquid pressure in the main supply line 12) decreases. At this time, however, a pressure deviation (ΔP in the figure) is generated due to a decrease in the main line pressure, so that pressure feedback control is executed to eliminate the pressure deviation, and the operating air pressure adjusted by the electropneumatic regulator 32 increases. As a result, the main line pressure gradually returns to the set pressure.

  Contrary to the above, when the branch line LNi is closed and the number of open branch lines is reduced, the flow of liquid to the branch line LNi is stopped as shown in FIG. The main line pressure temporarily rises, and then the operating air pressure drops by pressure feedback control, and then gradually returns to the set pressure.

  When pressure fluctuation occurs as the branch line increases or decreases as described above, the state in which the pressure deviation has occurred is gradually resolved by pressure feedback control (feedback control based on the deviation between the set pressure and actual pressure) after the pressure fluctuation. However, even if it is temporary, pressure fluctuation occurs, and it is desired to improve it.

  As a countermeasure against main line pressure fluctuation, in the present embodiment, when the number of open branch lines is increased or decreased, the increase / decrease of the operating air pressure is adjusted simultaneously with the increase / decrease of the number of lines. Specifically, as shown in FIG. 4A, when the number of open lines increases as the branch line LNi is newly opened, the operating air pressure is increased by a predetermined set value A at the same time as the line is opened. Let As a result, the amount of fluctuation in the main line pressure is smaller than when only the pressure feedback control is executed without increasing the operating air pressure at the same time as opening the line (the dashed line in the figure), and the set value is restored. Can be expedited.

  As shown in the figure, when a slight pressure fluctuation occurs, pressure feedback control is executed based on the pressure deviation (ΔP in the figure), and the operating air pressure increases accordingly.

  Further, as shown in FIG. 4B, when the number of open lines is reduced by closing the branch line LNi, the operating air pressure is lowered at a time by a predetermined set value A simultaneously with the closing of the line. As a result, as compared with the case where only the pressure feedback control is executed without decreasing the operating air pressure at the same time as the line is closed (the dashed line in the figure), the fluctuation amount of the main line pressure is small, and The return can be accelerated.

  Here, the value at which the operating air pressure is controlled when the branch line LNi is newly opened or closed, that is, what value the set value A is set to, is mainly determined by increasing or decreasing the number of branch lines opened. It is desirable to predict and determine how much the line pressure will fluctuate. In the present embodiment, operation air pressure control amount data in which the number of branch lines increase / decrease (the number of lines opened and closed simultaneously) and the increase / decrease amount of the operation air pressure are prepared in advance and the operation air pressure control amount data is included in the operation air pressure control amount data. Based on this, the set value A is determined each time. FIG. 5 (a) shows map data related to the operation air pressure control. The increase / decrease amount (α1, α2, α2) of the operation air pressure for each increase / decrease number (± 1, ± 2,... ± n) of the branch line. ... Αn) is defined. At this time, the larger the increase / decrease number of branch lines, the larger the value that is specified as the increase / decrease amount of the operating air pressure.

  Incidentally, when the passage opening areas of the branch lines LN1 to LNn are all the same, it is possible to simply define the increase / decrease amount of the operating air pressure for each increase / decrease number of the branch lines. When the passage opening areas of LN1 to LNn are not the same, it is desirable to define the amount of increase / decrease in the operating air pressure when opened / closed for each branch line. That is, as shown in FIG. 5B, the increase / decrease amount (β1, β2,... Βn) of the operating air pressure is defined for each branch line number (LN1, LN2,... LNn). In this case, for example, if the branch lines LN1 and LN2 are opened simultaneously, the increase / decrease amount of the operating air pressure is set to “β1 + β2”.

  Each data in FIGS. 5A and 5B is obtained in advance by adaptation or the like, and is stored and held in the memory 35 b in the controller 35.

  FIG. 6 is a flowchart showing the procedure of the liquid pressure control process, and this process is repeatedly executed by the controller 35 at a predetermined time period.

  In FIG. 6, in step S11, the basic control value of the operating air pressure is calculated by feedback calculation using PID or the like for the liquid pressure in the main supply line 12. Specifically, the deviation between the set pressure and the actual pressure (measured pressure by the pressure sensor 31) is calculated, and the basic control value of the operation air pressure of the electropneumatic regulator 32 is calculated based on the deviation.

  Thereafter, in step S12, it is determined whether or not a branch line opening / closing request has been made this time. This determination is made based on the branch line opening / closing signal input from the branch line control device 25, and an affirmative determination is made when there is a request to increase or decrease the number of branch lines.

  If there is no line opening / closing request, the process proceeds to step S13, and the calculated basic control value of the operating air pressure is directly calculated as a control command value for the electropneumatic regulator 32 (control command value = basic control value).

  If there is a line opening / closing request, the process proceeds to step S14. In step S14, the number of branch lines that are increased or decreased by the current opening / closing request is calculated based on the branch line opening / closing signal input from the branch line control device 25. At this time, numerical values such as “+1” and “−1” are calculated as the increase / decrease numbers of the branch lines.

  Thereafter, in step S15, an increase / decrease amount of the operating air pressure is calculated based on the number of increase / decrease of the branch line, and an increase / decrease correction value corresponding to the increase / decrease amount is calculated. At this time, the increase / decrease amount of the operation air pressure is calculated with reference to the operation air pressure control amount data shown in FIG. 5A, and the increase / decrease correction value is calculated corresponding to the increase / decrease amount. At this time, the increase / decrease amount of the operation air pressure is calculated with reference to the operation air pressure control amount data shown in FIG. 5B, and the increase / decrease correction value is calculated corresponding to the increase / decrease amount. Good.

  Thereafter, in step S16, the control command value of the electropneumatic regulator 32 is calculated by adding the increase / decrease correction value calculated in step S15 to the basic control value of the operating air pressure calculated in step S11 (control command value = basic). Control value + increase / decrease correction value).

  Finally, in step S17, a regulator drive signal corresponding to the control command value calculated in step S13 or S16 is output to the electropneumatic regulator 32. Thereby, the operation air pressure of the electropneumatic regulator 32 is adjusted appropriately.

  According to the embodiment described in detail above, the following excellent effects can be obtained.

  Since the drive of the electropneumatic regulator 32 is controlled in synchronization with the opening / closing of the branch line when the opening / closing request of each branch line is made, the flow rate change of the branch line is caused by changing the number of opening of the branch line. In addition, the pressure fluctuation in the main supply line 12 caused by the flow rate change can be suppressed. Further, in this configuration, it is not necessary to install a pressure sensor or a regulator for each of the branch lines LN1 to LNn, so that the configuration can be simplified. As described above, the liquid pressure can be appropriately controlled as desired while avoiding complication of the configuration. Thereby, the flow volume fluctuation | variation of the liquid which flows via each branch line LN1-LNn can be suppressed, and a liquid (cleaning liquid) can be stably supplied with respect to several washing | cleaning apparatus.

  The timing at which the branch line control device 25 outputs the opening / closing drive signal to the electromagnetic valve 23 and the timing at which the branch line opening / closing signal is output to the controller 35 of the pressure control unit 30 are simultaneously set. Since the opening / closing request of each branch line is determined based on the opening / closing signal, the opening / closing of the branch line and the drive control of the electropneumatic regulator 32 can be performed in synchronization. At this time, in addition to simultaneously executing the opening / closing of the branch line and the drive control of the electropneumatic regulator 32, it is also possible to execute them by shifting them back and forth by a predetermined time.

  Further, since the pressure feedback control is combined and executed, even if the pressure fluctuation temporarily occurs with the opening and closing of the branch line, the pressure fluctuation can be quickly eliminated.

  Operation air pressure control amount data defining the relationship between the number of branch line increases / decreases (the number of lines opened and closed simultaneously) and the operation air pressure increase / decrease amount is stored, and the electropneumatic regulator 32 is referred to the control amount data. Therefore, the pressure fluctuation in the main supply line 12 when the branch line is opened and closed can be suitably suppressed regardless of the number of branch lines that are simultaneously opened and closed. At this time, the operation air pressure control amount data is stored in the memory 35b in advance, so that the pressure control is compared with the configuration in which the increase / decrease amount of the operation air pressure is calculated each time according to various parameters related to the operating status of the system. Can be easily implemented.

  In addition, if it is the structure which prescribes | regulates the increase / decrease amount of the operation air pressure for every branch line number, even if the flow volume at the time of opening differs for every branch line, it is the main supply line 12 at the time of opening / closing of a branch line similarly. The pressure fluctuation can be suitably suppressed.

  By controlling the operating air pressure (pilot pressure) of the electropneumatic regulator 32, the valve opening state of the relief valve 31 is adjusted, and accordingly, the primary pressure of the relief valve 31 (that is, from the branch point of each branch line LN1 to LNn). Also, the liquid pressure on the downstream side) can be properly controlled. Accordingly, the liquid pressure and flow rate in the branch lines LN1 to LNn are stabilized.

  Since the pressure control unit 30 is provided on the downstream side of the branch points of the branch lines LN1 to LNn, even if particles (dust etc.) are generated in the relief valve 31 of the pressure control unit 30, the particles are transferred to the branch lines. It does not flow into LN1 to LNn. Therefore, it can be said that it is advantageous also in maintaining the cleanliness of the liquid.

  According to the above system, it is possible to realize a suitable cleaning operation or the like when manufacturing semiconductor products or chemical products. Therefore, effects such as productivity improvement and quality stability can be expected. In addition, an effect of simplifying the adjustment of the flow rate of the branch line at the time of starting the apparatus can be expected.

(Second Embodiment)
In the second embodiment, for a plurality of branch lines LN1 to LNi, it is obtained by teaching processing how much actuator control amount (operating air pressure) is actually required when the lines are opened or closed, and the teaching processing is performed. The driving of the electropneumatic regulator 32 is controlled using the teaching data acquired by the above.

  Specifically, regarding the teaching process, it is instructed which of the plurality of branch lines LN1 to LNi is to be opened and closed, and after that instruction, pressure feedback control is executed to obtain the feedback control amount at that time. At this time, the pressure feedback control is executed in a state in which the drive control of the electropneumatic regulator 32 (steps S14 to S16 in FIG. 6) performed in synchronization with the opening and closing of the branch line is stopped. It is possible to accurately grasp how much feedback control amount (actual control amount) is required. Thereby, good teaching data can be obtained. Then, the data is stored in association with each branch line opening / closing command. In the present embodiment, an electrically rewritable nonvolatile memory such as an EEPROM is used as at least a part of the memory 35b, and teaching data is stored in the EEPROM or the like. An external storage medium can also be used as a memory for storing teaching data.

  Teaching data is acquired when the system is started up, and is repeatedly executed periodically or irregularly after the system is started up. When operating this system in a factory, it may be performed before the start of work every day, for example. When teaching data is already stored in the memory 35b, the previous teaching data is updated with new teaching data.

  FIG. 7 is a flowchart showing the procedure of the teaching process, and this process is repeatedly executed by the controller 35 at a predetermined time period.

  In FIG. 7, in step S <b> 21, it is determined whether or not teaching of all opening / closing patterns has been completed for the plurality of branch lines LN <b> 1 to LNi. If the teaching has been completed for all patterns, the present process is terminated, and if not all patterns have been completed, the process proceeds to the subsequent step S22.

  In step S22, a branch line opening / closing pattern in the teaching process to be executed this time is determined. In the present embodiment, all the patterns of the number of lines that can be simultaneously opened and closed for a plurality of branch lines LN1 to LNi are sequentially commanded. Specifically, one line is opened, two lines are opened simultaneously,... N lines are opened simultaneously. Each pattern (all lines open) is prepared, and each pattern is selected in order.

  Thereafter, in step S23, the branch line control device 25 is commanded to open the branch valve 21 to open the branch line according to the open / close pattern determined each time. For example, if the pattern is one line open, only the first line LN1 is opened, and if the pattern is two lines open simultaneously, the first and second lines LN1 and LN2 are opened simultaneously.

  Thereafter, in step S24, pressure feedback control using PID or the like is executed. In this feedback control, as described above, the basic control value of the electropneumatic regulator 32 is calculated based on the deviation between the set pressure at each time and the actual pressure (measured pressure by the pressure sensor 31), and the basic control value is used as a control command. The drive of the electropneumatic regulator 32 is controlled as a value. At this time, since the electropneumatic regulator 32 is controlled only by the pressure feedback control, the main line pressure fluctuates after the opening / closing valve 21 is instructed, and the feedback control is executed to suppress the pressure fluctuation (FIG. 3 ( a)).

  In step S25, the feedback control amount calculated in the pressure feedback control is acquired as teaching data. In step S26, the feedback control amount is stored in the memory 35b in association with the opening / closing pattern (opening / closing command) of each branch line. At this time, if control amount data having the same number of open / close lines already exists in the memory 35b, the existing data is updated with the current teaching data. An update permission condition may be set. For example, new and old data are compared, and update is permitted only when the difference is within a predetermined value.

  The teaching is repeatedly executed until the line opening of all opening / closing patterns is completed. Then, after the teaching data of all the open / close patterns is prepared, the above-described liquid pressure control process (see FIG. 6) is executed using the teaching data.

  As described above, according to the second embodiment, when the system is in operation, drive control of the electropneumatic regulator 32 can be executed using teaching data obtained by teaching processing, so that controllability can be improved. . In this case, even if the flow rate change amount at the time of opening and closing the branch line changes due to a change with time or the like, it is possible to realize optimal control in accordance with the change.

(Third embodiment)
As described in the first embodiment, if the driving of the electropneumatic regulator 32 is controlled in synchronization with the opening / closing of the branch line (opening / closing operation of the opening / closing valve 21), the pressure fluctuation can theoretically be prevented from occurring. Although it is considered possible, if the electropneumatic regulator 32 is driven too early or too late, it is considered that pressure fluctuation occurs temporarily. That is, depending on the relationship between the timing at which the on-off valve 21 is opened and closed and the liquid flow rate in the branch line changes and the timing at which the electropneumatic regulator 32 is driven and the relief valve 31 is operated by the operating air pressure at that time, the increase side ( Pressure fluctuation on the positive side or on the negative side (negative side) will occur. As the reason, there is an operation delay on the on-off valve 21 side or the pressure control unit 30 side.

  Here, as shown in FIG. 8A, when the opening of the on-off valve 21 and the driving of the electropneumatic regulator 32 are simultaneously performed, the main line pressure (the liquid pressure in the main supply line 12) is a predetermined amount K. As described above, in the case of fluctuation to the decreasing side, it is considered that the timing at which the relief valve 31 is activated by the operating air pressure of the electropneumatic regulator 32 is later than the timing at which the liquid flow rate in the branch line changes due to opening / closing of the on / off valve 21. It is done. In such a case, as indicated by the alternate long and short dash line in the figure, the drive timing of the electropneumatic regulator 32 is advanced, and the timing at which the relief valve 31 operates is advanced. Thereby, the fluctuation | variation to the reduction | decrease side of the main line pressure can be suppressed, and the same pressure can be kept at a constant pressure.

  Further, as shown in FIG. 8B, when the opening of the on-off valve 21 and the driving of the electropneumatic regulator 32 are simultaneously performed, the main line pressure (the liquid pressure in the main supply line 12) is a predetermined amount K or more. In the case of fluctuation to the increasing side, the timing at which the relief valve 31 is activated by the operating air pressure of the electropneumatic regulator 32 is considered to be earlier than the timing at which the liquid flow rate in the branch line changes due to the opening / closing of the opening / closing valve 21. . In such a case, as indicated by the alternate long and short dash line in the figure, the drive timing of the electropneumatic regulator 32 is delayed, and the timing at which the relief valve 31 operates is delayed. Thereby, the fluctuation | variation to the increase side of the main line pressure can be suppressed, and the same pressure can be kept at a constant pressure.

  FIG. 9 is a flowchart showing a drive timing control process of the electropneumatic regulator 32. This process is repeatedly executed by the controller 35 at a predetermined time period.

  In FIG. 9, in step S31, the main line pressure immediately after the opening of the on-off valve 21 and the drive of the electropneumatic regulator 32 is read in response to the branch line opening request is read. In the subsequent step S32, the main line pressure is read. It is determined whether or not the amount has increased or decreased by a predetermined amount K or more. If step S32 is negative, the process is terminated. If step S32 is positive, the process proceeds to step S33.

  In step S33, it is determined whether or not the pressure fluctuation is a decrease-side fluctuation. If the pressure fluctuation is decreasing, the drive timing of the electropneumatic regulator 32 is advanced by a predetermined time (step S34). If the pressure fluctuation is on the increasing side, the drive timing of the electropneumatic regulator 32 is delayed by a predetermined time (step S35). The change of the drive timing of the electropneumatic regulator 32 is applied from the next opening / closing of the branch line.

  As described above, according to the third embodiment, since the drive timing of the electropneumatic regulator 32 is appropriately changed, a temporary pressure fluctuation occurs immediately after opening and closing of the branch line due to an operation delay in the on-off valve 21 and the electropneumatic regulator 32. Even if it occurs, it is possible to suppress the pressure fluctuation when the regulator is driven next time.

  Incidentally, when the electropneumatic regulator 32 is driven in response to a branch line closing request, the following configuration may be applied. That is, when an increased pressure change is detected immediately after the electropneumatic regulator 32 is driven in response to the branch line closing request, the drive timing of the electropneumatic regulator 32 is advanced. Similarly, when a decrease in pressure change is detected immediately after the electropneumatic regulator 32 is driven in response to the closing request, the drive timing of the electropneumatic regulator 32 is delayed. Thereby, the pressure fluctuation in the main supply line 12 can be more appropriately suppressed when the branch line is closed.

  The following configuration may be adopted as a countermeasure when pressure fluctuation occurs temporarily even if the driving of the electropneumatic regulator 32 is controlled in synchronization with opening and closing of the branch line (opening and closing operation of the on-off valve 21). That is, a change in the main line pressure after the regulator is driven is detected, and a control amount for the next and subsequent times for driving the regulator is corrected based on the detected pressure change.

  FIG. 10 is a flowchart showing a control amount correction process of the electropneumatic regulator 32. This process is repeatedly executed by the controller 35 at a predetermined time period.

  In FIG. 10, in step S41, the main line pressure immediately after the opening of the on-off valve 21 and the driving of the electropneumatic regulator 32 is executed in response to the branch line opening request is read. In the subsequent step S42, the main line pressure is read. It is determined whether or not the amount has increased or decreased by a predetermined amount K or more. When step S42 is denied, the process is terminated as it is, and when step S42 is affirmed, the process proceeds to step S43.

  In step S43, it is determined whether or not the pressure fluctuation is a decrease-side fluctuation. If the pressure fluctuation is on the decrease side, the regulator control amount correction value is increased (step S44). If the pressure fluctuation is on the increase side, the regulator control amount correction value is decreased (step S45). The initial value of the correction value is 0, and each time step S42 is affirmed, the correction value is updated by adding or subtracting a predetermined value from the previous value of the correction value. The correction values calculated in steps S44 and S45 are applied from the next branch line opening / closing.

  If the regulator control amount is too small, pressure fluctuations occur on the decrease side immediately after the regulator is driven. However, when the regulator is driven the next time or later, the correction value is used to correct (increase) the regulator control amount. The change in pressure becomes large, and the pressure fluctuation on the decreasing side is suppressed. In addition, when the regulator control amount is too large, pressure fluctuation occurs on the increasing side immediately after the regulator is driven, but by correcting (decreasing) the regulator control amount using the correction value at the next and subsequent regulator driving. The change in the operating air pressure is reduced, and the pressure fluctuation on the increasing side is suppressed.

  Incidentally, when the electropneumatic regulator 32 is driven in response to a branch line closing request, the following configuration may be applied. That is, when a pressure change on the increasing side is detected immediately after the electropneumatic regulator 32 is driven in response to the branch line closing request, the correction value of the regulator control amount is increased (the change in the operating air pressure is increased). . Similarly, when a decrease in pressure change is detected immediately after the electropneumatic regulator 32 is driven in response to the closing request, the correction value of the regulator control amount is decreased (change in the operation air pressure is decreased). Thereby, the pressure fluctuation in the main supply line 12 can be more appropriately suppressed when the branch line is closed.

(Another embodiment)
The present invention is not limited to the description of the above embodiment, and may be implemented as follows, for example.

  In the above embodiments, the configuration in which the pressure control unit 30 is provided on the downstream side of the branch lines LN1 to LNn in the main supply line 12 has been described, but this is changed as shown in FIG. In FIG. 11, in the main supply line 12, the pressure control unit 60 is provided upstream of the branch points of the branch lines LN1 to LNn. The pressure control unit 60 includes a pilot-operated pressure regulator 61 provided on the main supply line 12, an electropneumatic regulator 62 that adjusts the pressure (pilot pressure) of operation air supplied to the regulator 61, and the main supply line 12. A pressure sensor 63 for detecting the liquid pressure (secondary pressure of the pressure regulator 61) and a controller 65 composed of a microcomputer having a CPU 65a, a memory 65b, and the like.

  The pressure detection signal from the pressure sensor 63 is sequentially input to the controller 65. The controller 65 adjusts the pressure of the operation air discharged from the electropneumatic regulator 62 based on the liquid pressure (actual pressure) calculated from the pressure detection signal. By adjusting the operating air pressure by the electropneumatic regulator 62, the liquid pressure in the main supply line 12 (secondary pressure of the pressure regulating valve 61) is controlled to the set pressure at each time. In addition, the controller 65 controls the driving of the electropneumatic regulator 62 in synchronization with the opening / closing of the branch line in response to the opening / closing request of each branch line. However, since the details are the same as the processing contents of the controller 35 in the first embodiment, the description thereof is omitted here.

  Also in the above configuration, as in the first embodiment, the liquid pressure can be appropriately controlled as desired while avoiding complication of the configuration. Thereby, the flow volume fluctuation | variation of the liquid which flows through each branch line LN1-LNn can be suppressed.

  In the above embodiment, the branch line open / close signal output from the branch line control device 25 is input to the controller 35 of the pressure control unit 30, and the controller 35 determines whether or not there is a request to open / close each branch line based on the branch line open / close signal. I decided to change this. For example, the opening / closing drive signal output from the branch line control device 25 to the electromagnetic valve 23 is also output to the controller 35 in the same manner, and the controller 35 requests the opening / closing of each branch line based on the opening / closing drive signal. The structure which determines presence or absence may be sufficient. The controller 35 may centrally manage which branch line LN1 to LNn circulates the liquid, and may determine that there is an opening / closing request by itself when changing the number of opened branch lines.

  In the above embodiment, the pressure feedback control is executed as the liquid pressure control, but the pressure feedback control may not be executed. In this case, even if the pressure feedback control is not executed, when the opening / closing request for each branch line is requested as described above, the actuator control amount corresponding to the flow rate change of the branch line accompanying the opening / closing is calculated and the branch line is opened / closed. By controlling the driving of the electropneumatic regulator 32 based on the actuator control amount in synchronization, the liquid pressure in the main supply line 12 can be properly controlled. According to such a configuration, the pressure sensor 33 is not necessary, and the cost can be reduced.

  In the second embodiment, in the teaching process, all the patterns of the number of lines that can be simultaneously opened and closed for the plurality of branch lines LN1 to LNi are sequentially commanded (step S22 in FIG. 7). It is good also as a structure which sequentially instruct | indicates to open or close the said branch line one by one about several branch lines LN1-LNn. This makes it possible to acquire teaching data individually for all branch lines that are opened and closed in response to a request. In this case, even if the liquid flow rate at the time of opening is different for each branch line, or even if there is an individual difference, teaching data can be suitably acquired by coping with it.

  In the second embodiment, when teaching the actuator control amount (the adjustment amount of the operating air pressure), the controller 35 of the pressure control unit 30 determines the opening / closing pattern of the branch line, and the branch line control device according to the opening / closing pattern. However, this is changed. For example, when teaching the actuator control amount (operation air pressure adjustment amount), the branch line control device 25 determines the branch line opening / closing pattern and issues an opening / closing command to the controller 35 according to the opening / closing pattern. Good.

  The opening area (that is, the opening degree of the on-off valve 21) in each of the branch lines LN1 to LNn can be variably adjusted. When each of the branch lines LN1 to LNn is opened or closed, 21), the control amount of the electropneumatic regulator 32 may be determined. For example, when the opening area of the branch line is smaller than the area when fully opened, the control amount of the electropneumatic regulator 32 is corrected to be reduced by taking that amount into account.

  A pump having a metering function may be used as the pump 13 (pressure feeding means) provided in the main supply line 12, and the liquid discharge amount by the pump may be adjusted according to the number of open branch lines.

The lineblock diagram showing the outline of the liquid supply system in a 1st embodiment. Sectional drawing which shows the structure of a relief valve. The time chart for demonstrating that the fluctuation | variation of the main line pressure arises at the time of opening and closing of a branch line. The time chart for demonstrating the outline | summary of liquid pressure control concretely. The figure which shows the map data regarding operation air pressure control. The flowchart which shows the procedure of a liquid pressure control process. The flowchart which shows the procedure of a teaching process in 2nd Embodiment. The time chart for demonstrating the outline | summary of the drive timing control of an electropneumatic regulator in 3rd Embodiment. The flowchart which shows the drive timing control process of an electropneumatic regulator in 3rd Embodiment. The flowchart which shows the controlled variable correction process of an electropneumatic regulator in 3rd Embodiment. The block diagram which shows the outline of the liquid supply system in another embodiment. The block diagram which shows the outline of the liquid supply system in a prior art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Liquid tank, 12 ... Main supply line, 13 ... Pump, 21 ... On-off valve, 30 ... Pressure control part, 31 ... Relief valve, 32 ... Electropneumatic regulator, 33 ... Pressure sensor, 35 ... Controller, 35b ... Memory, 60 ... Pressure controller, 61 ... Regulator, 62 ... Electro-pneumatic regulator, 63 ... Pressure sensor, 65 ... Controller, 65b ... Memory, LN1 to LNn ... Branch line.

Claims (11)

A liquid passage through which liquid flows;
A pumping means provided in the middle of the liquid passage for pumping the liquid;
A plurality of branch passages branched from the liquid passage;
A pressure adjusting actuator provided in the middle of the liquid passage for adjusting the liquid pressure in the liquid passage;
A liquid supply system that individually opens or closes the plurality of branch passages and distributes the liquid from the liquid passage through the opened branch passages.
When the opening or closing of the branch passages is required, the control amount calculating means for calculating a control amount of the pressure adjustment actuator corresponding to the flow rate change in the branch passage accompanying the opening or closing,
Actuator control means for controlling the drive of the pressure adjusting actuator based on the actuator control amount calculated by the control amount calculation means in synchronization with opening and closing of the branch passage;
Equipped with a,
Control amount data defining the relationship between the number of the branch passages opened and closed simultaneously and the actuator control amount is stored in a storage device,
The liquid supply system according to claim 1, wherein the control amount calculation means calculates the actuator control amount with reference to the control amount data when the branch passage according to the request is opened and closed . A liquid passage through which liquid flows;
A pumping means provided in the middle of the liquid passage for pumping the liquid;
A plurality of branch passages branched from the liquid passage;
A pressure adjusting actuator provided in the middle of the liquid passage for adjusting the liquid pressure in the liquid passage;
A liquid supply system that individually opens or closes the plurality of branch passages and distributes the liquid from the liquid passage through the opened branch passages.
When the opening or closing of the branch passages is required, the control amount calculating means for calculating a control amount of the pressure adjustment actuator corresponding to the flow rate change in the branch passage accompanying the opening or closing,
Actuator control means for controlling the drive of the pressure adjusting actuator based on the actuator control amount calculated by the control amount calculation means in synchronization with opening and closing of the branch passage;
Equipped with a,
Storing, in a storage device, path-specific data defining the actuator control amount corresponding to the flow rate change accompanying opening and closing of the plurality of branch paths for each branch path;
The liquid supply system according to claim 1, wherein the control amount calculation means calculates the actuator control amount with reference to the data for each passage when opening and closing the branch passage according to the request . Pressure detecting means for detecting a liquid pressure in the liquid passage;
Feedback control means for feedback-controlling the control amount of the pressure adjusting actuator so that the liquid pressure detected by the pressure detection means matches a target value;
Liquid supply system according to claim 1 or 2, further comprising a. A liquid passage through which liquid flows;
A pumping means provided in the middle of the liquid passage for pumping the liquid;
A plurality of branch passages branched from the liquid passage;
A pressure adjusting actuator provided in the middle of the liquid passage for adjusting the liquid pressure in the liquid passage;
A liquid supply system that individually opens or closes the plurality of branch passages and distributes the liquid from the liquid passage through the opened branch passages.
When the opening or closing of the branch passages is required, the control amount calculating means for calculating a control amount of the pressure adjustment actuator corresponding to the flow rate change in the branch passage accompanying the opening or closing,
Actuator control means for controlling the drive of the pressure adjusting actuator based on the actuator control amount calculated by the control amount calculation means in synchronization with opening and closing of the branch passage;
Pressure detecting means for detecting a liquid pressure in the liquid passage;
Feedback control of the control amount of the pressure adjusting actuator so that the liquid pressure detected by the pressure detecting means matches a target value,
Open / close command means for commanding to open / close at least one of the plurality of branch passages;
After the command by the opening / closing command means, the feedback control is executed in a state where the control of the actuator for pressure adjustment by the actuator control means is stopped, and the actual control amount obtained by the feedback control is changed to the opening / closing command for each branch passage. Control amount storage means for storing in association with
The liquid supply system according to claim 1, wherein the control amount calculation unit calculates an actuator control amount each time using the actual control amount stored by the control amount storage unit . 5. The liquid supply system according to claim 4 , wherein the opening / closing command means sequentially commands all patterns corresponding to the number of branch paths that can be simultaneously opened / closed for the plurality of branch paths. 5. The liquid supply system according to claim 4 , wherein the opening / closing command means sequentially commands the branch passages to be opened or closed one by one with respect to the plurality of branch passages. Pressure change detection means for detecting a pressure change in the liquid passage after the actuator is driven by the actuator control means;
Timing control means for changing the drive timing of the actuator for pressure adjustment by the actuator control means based on the pressure change detected by the pressure change detection means;
Liquid supply system according to any one of claims 1 to 6, further comprising a. The timing control means advances the actuator drive timing when the pressure change detecting means detects a decreasing pressure change when the branch passage opening is requested, and the pressure change detecting means is also used when the opening request is requested. 8. The liquid supply system according to claim 7 , wherein the actuator drive timing is delayed when a pressure change on the increase side is detected. Pressure change detection means for detecting a pressure change in the liquid passage after the actuator is driven by the actuator control means;
Based on the pressure change detected by the pressure change detection means, a control amount correction means for correcting the actuator control amount from the next time on by the actuator control means;
Liquid supply system according to any one of claims 1 to 6, further comprising a. As the pressure adjusting actuator, a pilot-actuated relief valve provided downstream of the branch point of each branch passage in the liquid passage, and a pilot pressure adjusting means for adjusting a pilot pressure acting on the relief valve. Prepared,
The control amount calculating means, as the actuator control amount, any one of claims 1 to 9 and calculates a control amount corresponding to the pilot pressure for eliminating the pressure change accompanying the opening and closing of the branch passage Liquid supply system as described in. As the pressure adjusting actuator, a pilot-actuated pressure adjusting valve provided upstream of the branch point of each branch passage in the liquid passage, and a pilot pressure adjusting means for adjusting a pilot pressure acting on the pressure adjusting valve And
The control amount calculating means, as the actuator control amount, any one of claims 1 to 9 and calculates a control amount corresponding to the pilot pressure for eliminating the pressure change accompanying the opening and closing of the branch passage Liquid supply system as described in.

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