JP5879280B2 - Liquid chromatograph liquid feeding device and liquid chromatograph device - Google Patents

Description

  The present invention relates to a liquid chromatograph, and more particularly to a liquid chromatograph liquid feeding device and a liquid chromatograph device that perform liquid feeding control with high accuracy.

  An analysis technique using a liquid chromatograph is required to be highly accurate. For this reason, it is important that liquid feeding of the mobile phase by the liquid feeding device is accurately controlled.

  Here, the control of the low pressure gradient liquid feeding is performed by combining the liquid feeding operation of the liquid feeding pump main body which is a liquid feeding device and the operation of the valve for switching the flow path of the liquid to be fed. In Patent Document 1, a plurality of components in a mobile phase to be fed are detected and the concentration is calculated, a mixing ratio error with a set mixing ratio is calculated based on the component concentration, and the mixing ratio error is electromagnetically detected. A technique for feeding back the valve switching timing is disclosed.

JP 2002-243712 A

  In Patent Document 1, the accuracy of the mixing ratio is improved by adjusting the switching timing of the solenoid valve. However, in actuality, the operation of the solenoid valve is not performed instantaneously but with a certain time width. Here, when the solenoid valve performs an operation of switching between opening and closing, a variation in this operation may affect the flow rate of the mobile phase to be fed.

  In the technique disclosed in Patent Document 1, since the variation in the transient operation is not taken into consideration, more accurate control cannot be performed.

  An object of the present invention is to provide an apparatus and a method for realizing a more precise control of liquid feeding by reducing a change in flow rate and pressure of a mobile phase due to variations and characteristics of valve opening / closing operations on a flow path. That is.

  As an aspect for solving the above-described problems, the present invention has the following characteristics.

  That is, a liquid feeding section that feeds liquid, a valve that is disposed on a flow path of liquid fed from the liquid feeding section, and that performs an opening and closing operation, and a control that controls the operation of the liquid feeding section and the valve And the control unit provides a device for controlling the operation of the liquid feeding unit based on the timing of the opening / closing operation of the valve, and a method using the device.

  ADVANTAGE OF THE INVENTION According to this invention, regarding the liquid feeding of a liquid chromatograph, the influence which the variation in the opening / closing operation | movement of a valve has on the flow volume and pressure of a liquid can be reduced, and highly accurate liquid feeding control can be implement | achieved.

The figure which shows schematic structure of the liquid feeding apparatus which concerns on embodiment of this invention. The figure which shows the whole structure of the liquid feeding apparatus which concerns on 2nd embodiment of this invention. The figure explaining the relationship between the switching of the solenoid valve which concerns on embodiment of this invention, and the mixing ratio in a mobile phase The figure explaining the valve opening instruction | command given to the solenoid valve which concerns on embodiment of this invention, and the displacement of a solenoid valve The figure explaining the relationship between operation | movement of the conventional solenoid valve, and the liquid feeding speed of a liquid feeding pump The figure explaining the 1st example of the relationship between operation | movement of the solenoid valve which concerns on embodiment of this invention, and the liquid feeding speed of a liquid feeding pump The figure explaining the 2nd example of the relationship between operation | movement of the solenoid valve which concerns on embodiment of this invention, and the liquid feeding speed of a liquid feeding pump. The figure explaining the 3rd example of the relationship between operation | movement of the solenoid valve which concerns on embodiment of this invention, and the liquid feeding speed of a liquid feeding pump. The figure explaining the 4th example of the relationship between operation | movement of the solenoid valve which concerns on embodiment of this invention, and the liquid feeding speed of a liquid feeding pump. The figure explaining the 5th example of the relationship between operation | movement of the solenoid valve which concerns on embodiment of this invention, and the liquid feeding speed of a liquid feeding pump. The figure which shows the whole structure of the liquid feeding apparatus which concerns on 3rd embodiment of this invention. The figure which shows the valve opening operation | movement of (alpha) flow path of the wake switching valve which concerns on 3rd embodiment of this invention. The figure which shows valve opening operation | movement of (beta) flow path of the wake switching valve which concerns on 3rd embodiment of this invention The figure explaining operation | movement of the solenoid valve which concerns on 2nd embodiment of this invention. 1 is a system configuration diagram of a liquid chromatograph apparatus according to an embodiment of the present invention. Basic operation flow diagram of liquid feeding control according to an embodiment of the present invention The figure which shows the example of a structure of the solenoid valve which concerns on embodiment of this invention The figure which shows the position structure of the flow-path switching valve which concerns on 4th embodiment of this invention. The figure which shows the whole structure of the autosampler (sample injection part) in the liquid chromatograph which concerns on 4th embodiment of this invention. The figure which shows the connection relationship of the synchronizing signal between the liquid feeding pump and autosampler which concern on 4th embodiment of this invention. The figure which shows the relationship between the operation | movement of the flow-path switching valve which concerns on 4th embodiment of this invention, and a liquid feeding pump liquid feeding speed. The figure which shows the 1st example of the relationship between operation | movement of the flow-path switching valve which concerns on 4th embodiment of this invention, and rotation of the motor of a liquid feeding pump. The figure which shows the 2nd example of the relationship between operation | movement of the flow-path switching valve which concerns on 4th embodiment of this invention, and rotation of the motor of a liquid feeding pump. The figure which shows the 3rd example of the relationship between operation | movement of the flow-path switching valve which concerns on 4th embodiment of this invention, and rotation of the motor of a liquid feeding pump. The comparison figure which shows the pressure of the liquid feeding pump when not applying / applying the control method of the liquid feeding pump concerning embodiment of this invention The comparison figure which shows the pressure of the column inlet in the case where the control method of the liquid feeding pump which concerns on embodiment of this invention is not applied / when it applies

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 15 is a system configuration diagram of the liquid chromatograph apparatus according to the embodiment of the present invention. The liquid chromatograph apparatus shown in this figure is a liquid chromatograph unit 1501 where a mixed sample is separated and analyzed, and a control device for controlling each apparatus related to the liquid chromatograph unit 1501 based on a predetermined measurement method. A control unit 1509 is provided.

  The liquid chromatograph unit 1501 receives a liquid feeding device (liquid feeding unit) 1502 that sends an eluent based on a command from the control unit 1509 and the eluent sent from the liquid feeding device 1502 from the control unit 1509. Autosampler that injects a sample based on the command of the sample, (sample injection unit) 1503, a column (separation unit) 1504 that separates components in the sample, and components separated by the column are detected and converted into electrical signals. A detector (detection unit) 1505 that outputs to the control unit 1509 is provided.

  The control unit 1509 includes a data processing device 1507 that executes command and data exchange with each device related to the liquid chromatograph unit 1501, an input device 1506 that receives an instruction from the operator, and a detection result obtained by the detector 1505. And an output device 1508 for displaying a graphical user interface (GUI) and the like related to various operations of the liquid chromatograph unit 1501 and the control unit 1509. The measured value of each component detected by the detector 1505 is taken into the data processing device 1507, and the analysis result of the sample is transmitted and displayed on the output device 1508.

  Next, the liquid delivery apparatus according to the embodiment of the present invention will be described with reference to FIG.

  The liquid feeding device includes a liquid feeding control unit 1, an actuator 95, a liquid feeding pump 94, and an electromagnetic valve 93.

  The liquid feed pump 94 performs a pump operation of sucking the liquid feed from the suction port and pushing it out from the discharge port by the driving force from the actuator 95.

  The electromagnetic valve 93 is installed on the suction side of the liquid feed pump 94 and is configured to control the flow from the liquid feed tank 91 in this example. The solenoid valve 93 operates in accordance with a command from the liquid feeding control unit 1 described later, and is configured to open when energized and to pass liquid, and when energized, the flow path of the liquid is closed and closed by the force of the spring. Have.

  The liquid feeding control unit 1 is provided in the data processing device 1507 shown in FIG. The data processor 1507 receives a command relating to the mobile phase feeding amount, the feeding rate, etc., and generates a driving command for the actuator 95 and an opening / closing command for the electromagnetic valve 93.

  The actuator 95 includes a motor and a sensor, and is configured to receive a drive command from the liquid feeding control unit 1 to rotate the motor and supply the power to the liquid feeding pump.

  The operation of the liquid delivery device according to the present embodiment shown in FIG. 1 will be described below.

  Here, it is assumed that the initial suction operation of the necessary liquid, the operation of returning the origin of the actuator 95, and the like have been completed, and the liquid feeding device is ready to be moved.

  When performing highly precise liquid feeding control, the solenoid valve 93 is, for example, a liquid feeding pump for keeping the pressure of each part constant, preventing air suction due to backflow, and preventing liquid movement due to gravity. It is installed around 94.

  In the embodiment of the present invention, an electromagnetic valve 93 is installed between the suction port of the liquid feed pump 94 and the liquid feed tank 91 as shown in the drawing in order to prevent the liquid flow of the suction flow path 92 of the liquid feed pump 94. The liquid flow is cut off when the liquid feed pump 94 is stopped.

  Here, when liquid feeding is performed by operating the liquid feeding pump 94, liquid feeding is performed in a state where the electromagnetic valve 93 is opened. However, the operation of the electromagnetic valve 93 is not performed instantaneously, and a certain amount of time is required between the start and end of the opening / closing operation.

  FIG. 4 is a diagram for explaining the operation of the electromagnetic valve according to the embodiment of the present invention.

  In the process of switching the opening and closing of the electromagnetic valve 93, the operation of the electromagnetic valve 93 varies as shown in the figure. Furthermore, the time required to reach a sufficiently open state or a sufficiently closed state varies depending on operating conditions and the like. Here, if the liquid feed pump 94 is operated in such a state that the state of the electromagnetic valve 93 varies, the relationship between the liquid feed amount of the liquid feed pump 94 and the opening area of the electromagnetic valve 93 varies, and as a result There is a risk of causing variations in flow rate and instantaneous pressure fluctuations.

  In the operation control according to the embodiment of the present invention, as shown in a graph 101 representing a change in the liquid feeding speed of the liquid feeding pump over time and a graph 102 representing an opening / closing operation of the electromagnetic valve 93 in FIG. While 93 is in the middle of the opening / closing operation, the liquid feed pump 94 is controlled to stop. That is, after the electromagnetic valve 93 is sufficiently opened, the liquid feeding pump 94 is started to move, and after the liquid feeding pump 94 is stopped, the electromagnetic valve 93 is closed.

  That is, when the electromagnetic valve 93 performs an opening operation, the liquid supply control unit 1 supplies a signal instructing the electromagnetic valve 93 to start the opening operation, and then issues a stop signal to the liquid supply pump 94. After detecting that the electromagnetic valve 93 is fully opened by the sensor, the instruction to start the operation of the liquid feeding pump 94 is issued. Next, when performing the closing operation of the electromagnetic valve 93, a stop signal is first output to the liquid feed pump 94, and after stopping the operation, a signal instructing the electromagnetic valve 93 to start the closing operation is supplied.

  Here, FIG. 17 is a diagram showing a configuration of the electromagnetic valve 93 according to the embodiment of the present invention. As described above, when an opening / closing command is given to the electric circuit 1701 by the liquid feeding control unit 1, electric energy is converted into mechanical energy by the solenoid 1702. Due to the mechanical energy, the valve body 1703 is moved and displaced, and a sensor such as the Hall element 1704 detects the displacement. Thus, based on the detection of the displacement of the valve, the liquid feed speed of the liquid feed pump 94 is adjusted.

  FIG. 16 shows a basic operation flow of liquid feeding control according to the embodiment of the present invention. This control is performed by the liquid feeding control unit 1 (see FIG. 1) in the data processing device 1507 of FIG.

  First, the opening operation of the electromagnetic valve 93 will be described. After instructing the electromagnetic valve 93 to start the opening operation (S1601), the liquid feed pump 94 is instructed to stop the operation (S1602). After detecting that the electromagnetic valve 93 is fully opened by a sensor such as the hall element 1704 (S1603), the liquid feed pump 94 is instructed to start operation (S1604). Next, the closing operation of the electromagnetic valve 93 will be described. In this case, after instructing the liquid feed pump 94 to stop the operation (S1605), the solenoid valve 93 is instructed to start the closing operation (S1606). The above operation is repeated until the end of analysis (S1607).

  By such control, the liquid feeding amount of the above-described liquid feeding pump 94 is not affected by the fluctuation of the opening area of the electromagnetic valve 93 during the opening / closing operation, and the liquid feeding operation can be performed stably.

  Here, in the present embodiment, an example in which the electromagnetic valve 93 is installed on the suction side of the liquid feed pump 94 is shown, but the installation location of the electromagnetic valve 93 is not specified, and the installation position of the electromagnetic valve 93 is the discharge side. Or both.

  In addition, although the example which stops the liquid feeding pump 94 at the time of the opening / closing operation | movement of the solenoid valve 93 was shown, according to the objective of the liquid feeding apparatus, either the liquid feeding pump speed was reduced or increased during the operation. The speed may be adjusted.

  Moreover, although the example which used the electromagnetic valve 93 as a valve for liquid feeding control was shown, it is not restricted to this, The structure which carries out liquid feeding control with other motive power may be sufficient.

  As described above, according to the present embodiment, by performing the liquid feeding control of the liquid feeding pump 94 according to the state of the opening / closing operation of the electromagnetic valve 93, the variation amount of the liquid feeding flow rate due to the variation of the valve operation. Further, by reducing fluctuations in pressure, liquid feeding control with higher accuracy can be realized.

  Hereinafter, the liquid feeding device according to the second embodiment of the present invention will be described with reference to FIG.

  FIG. 2 shows the configuration of the entire liquid delivery device.

  The liquid feeding device includes a liquid feeding controller, an actuator, a liquid feeding pump, and a liquid feeding switching valve (here, a case where an electromagnetic valve is used will be described. Hereinafter, electromagnetic valves 43 and 53).

  The liquid feed pump has a structure in which two plunger pumps are connected in series. The first plunger 2P and the second plunger 3P are reciprocated by the first actuator 2A and the second actuator 3A, respectively. Pressurization and depressurization of the liquid feeding in the first cylinder 2C and the second cylinder 3C are performed.

  Here, a first check valve 2CV is installed at the suction port of the first cylinder 2C, and a second check valve 3CV is installed at the suction port of the second cylinder. Each check valve is installed so as to allow liquid to be sucked into the cylinder and not to allow liquid to be discharged from the cylinder.

  Here, the flow path of the liquid feeding is connected in the order of the first check valve 2CV to the first cylinder 2C, then the second check valve 3CV to the second cylinder 3C, and the discharge pipe 7. The discharge pipe 7 It is connected to analyzers including autosamplers, columns, and detectors.

  With such a connection, when an appropriate reciprocating motion is given to each of the first and second plungers, the liquid is sucked from the first check valve 2CV and pressurized by the two plungers 2P and 3P. The liquid is sent, passes through the second cylinder 3C, and is discharged from the discharge pipe 7.

  The liquid feed switching solenoid valves (A solenoid valve 43 and B solenoid valve 53) are installed on the suction side of the liquid feed pump, and in this example, are configured to switch between two types of liquids, A liquid and B liquid. In the liquid A, the flow path of the liquid is connected from the liquid A tank 41 through the liquid A suction pipe 42 to the solenoid valve 43 and the suction pipe 6 to the first cylinder. In the B liquid, the flow path of the liquid supply is connected from the B liquid tank 51 through the B liquid suction pipe 52 to the B electromagnetic valve 53 and the suction pipe 6 to the first cylinder 2C.

  Here, the suction pipe 6 to the first cylinder 2C is T-shaped, and the flows of the liquid A and the liquid B merge here. Each of the A solenoid valve 43 and the B solenoid valve 53 operates in response to a command from the liquid feeding control unit 1. When energized, the A solenoid valve 43 and the B electromagnetic valve 53 are in an open state. Closed and closed.

  The liquid feeding control unit 1 is provided in the data processing device 1507 shown in FIG. The data processor 1507 receives a command related to the mobile phase liquid supply amount, liquid supply speed, and the like, and generates an actuator drive command and an opening / closing command for the A solenoid valve 43 and the B solenoid valve 53.

  Although the detailed structure of the actuator is not shown in the figure, it is composed of a motor, a sensor, a rotation / linear motion conversion mechanism, etc., receives a drive command from the liquid feeding control unit 1, rotates the motor, and moves the motion by the rotation / linear motion conversion mechanism. Instead of linear motion, the plungers 2P and 3P are reciprocated.

  Here, in the present embodiment, a configuration using two types of liquids A and B is shown, but a configuration in which a plurality of three or more types of liquids are mixed may be used.

  In addition, a filter, a mixer, or the like can be installed in the liquid flow path depending on the purpose.

  The operation of the liquid delivery device according to the present embodiment will be described below with reference to FIG.

  It is assumed that the initial suction operation of the necessary liquid, the operation of returning the plunger to the origin, and the like are completed, and the preparation for moving the liquid feeding device is completed.

  The basic operation of the liquid feeding device is to reciprocate the first plunger 2P at a constant period to suck liquid from the suction pipe 6 and send it to the second plunger 3P. The second plunger 3P While reciprocating with one plunger 2P, it is reciprocated in the opposite phase. That is, the second plunger 3P performs a discharge operation in a section in which the first plunger 2P performs a suction operation, and conversely, the second plunger 3P performs a suction operation in a section in which the first plunger 2P performs a discharge operation. Like that. Here, when the ratio of the stroke volume of the first plunger 2P to the stroke volume of the second plunger 3P is 2: 1, the discharge of the second plunger 3P obtained as the sum of the liquid feeding operations of the two plungers is always performed. A constant flow rate is obtained continuously.

  Next, paying attention to the suction operation of the liquid feed pump, that is, the flow of the liquid in the suction pipe 6, here, the suction of the liquid feed is intermittently performed in synchronization with the operation of the first plunger 2P. Solenoid valves 43 and 53 are disposed upstream of the suction pipe 6. The A solenoid valve 43 performs liquid feeding control of the A liquid, and the B electromagnetic valve 53 performs liquid feeding control of the B liquid. The mixing ratio is adjusted.

  FIG. 3 shows the relationship between the switching of the solenoid valve and the mixing ratio in the mobile phase according to the embodiment of the present invention.

  As described above, the suction operation of the liquid feeding pump is performed intermittently, and a section corresponding to this suction is shown as a suction stroke. During this intake stroke, first, the A solenoid valve 43 is opened and the B solenoid valve 53 is closed in the portion A shown in the figure. Next, in the portion B shown in the figure, the A electromagnetic valve 43 is closed and the B electromagnetic valve 53 is opened. Assuming that the operating speed of the first plunger 2P of the liquid feed pump in the suction stroke is constant, an amount of liquid proportional to the open time of the electromagnetic valves 43 and 53 in the suction stroke is sucked into the first cylinder 2C. Will be. Therefore, when changing the mixing ratio of the liquid feeding, the required mixing ratio can be realized by changing the time ratio of the open state of the A solenoid valve 43 and the B solenoid valve 53 as shown in FIG.

  Here, when attention is paid to the operation of the electromagnetic valve, it is shown in FIG. FIG. 4 shows the relationship between the valve opening command given to the solenoid valve and the displacement of the solenoid valve. When the electromagnetic valve receives a valve opening command, the electromagnet is energized and excited, and the valve is moved by the generated magnetic attractive force to open and close the liquid flow path.

  Here, there is a delay in the rise of the actual electromagnetic force, and variations in actual valve displacement occur as shown in the figure due to changes in inductance caused by the attraction of the magnetic material, resistance of the liquid that the valve pushes away, and the like. A section where the displacement of the valve varies is indicated by a symbol td.

  FIG. 5 shows the relationship between the operation of the conventional solenoid valve and the liquid feed speed of the liquid feed pump when the liquid to be sucked is switched using two solenoid valves in the suction stroke.

  In this case, in order to prevent generation of a large negative pressure in the liquid feed pump, suction is performed after opening the electromagnetic valve, and even when switching, the B electromagnetic valve 53 is opened while the A electromagnetic valve 43 is closed, and all the electromagnetic valves are closed. The operation of changing the liquid feed speed of the liquid feed pump is performed before. As shown in the figure, there are three sections td where the displacement of the electromagnetic valve varies, and the suction operation by the liquid feeding pump is continued in that section as a result. , And is sucked into the first cylinder 2C (see FIG. 2), leading to deterioration in the accuracy of the liquid feed mixing ratio.

  The operation | movement in the suction stroke of the liquid feeding apparatus which concerns on this Embodiment is shown in FIG. According to the present invention, in the section in which the A solenoid valve 43 and the B solenoid valve 53 are operating, the liquid feed speed of the liquid feed pump is decreased and stopped. That is, a command to open the A solenoid valve 43 is issued first, and the suction operation of the liquid feeding pump is performed after the A solenoid valve 43 is sufficiently opened. Next, after stopping the suction operation of the liquid feed pump, a command to close the A solenoid valve 43 and to open the B solenoid valve 53 is issued. After the A solenoid valve 43 is sufficiently closed and the B solenoid valve 53 is fully opened, the suction operation of the liquid feeding pump is performed. Next, after the suction operation of the liquid feeding pump is stopped, the B solenoid valve 53 is closed. Here, as described above with reference to FIG. 17, whether or not the electromagnetic valve is sufficiently opened or closed is determined by confirming the displacement of the valve element using a sensor such as a Hall element. Thereby, since the suction is not performed in the section td in which the displacement of the electromagnetic valve varies, the suction amount can be controlled stably and accurately. In addition, although the example which waits until a valve complete | finishes operation | movement fully and operates a liquid feeding pump was demonstrated here, it is not limited to this, Liquid feeding is considered after progress of delay time of valve displacement. The pump operation may be started.

  FIG. 7 shows a second example of the relationship between the operation of the solenoid valve and the liquid feed speed of the liquid feed pump according to the embodiment of the present invention. As shown in this figure, the liquid feeding speed of the liquid feeding pump is not completely stopped but can be controlled to be lower than the speed at the time of inhalation. According to such control, even if the speed change time of the liquid feed pump is longer than the opening / closing operation time of the solenoid valve and the speed change cannot catch up, it can be dealt with.

  FIG. 8 shows a third example of the relationship between the operation of the solenoid valve and the liquid feed speed of the liquid feed pump according to the embodiment of the present invention. As shown in the figure, after the liquid feeding speed of the liquid feeding pump is reduced at the time of switching of the solenoid valve, the suction from the B solenoid valve 53 is performed at a low speed without returning to the normal speed. Also good. In this case, since the opening time of the B solenoid valve 53 can be made longer than the normal speed of the liquid feed pump, the time ratio of the section td having a variation when switching the solenoid valve is relatively lowered. Can do. Therefore, even when the opening time of the B solenoid valve 53 is short and the speed change of the liquid feed pump cannot keep up, the accuracy of the mixture ratio control can be improved.

  FIG. 9 shows a fourth example of the relationship between the operation of the solenoid valve and the liquid feed speed of the liquid feed pump according to the embodiment of the present invention. The control shown in this figure can also be performed as another countermeasure when the opening time of the B solenoid valve 53 is short and the speed change of the liquid feed pump cannot catch up. As shown in this figure, the section where the liquid feeding speed of the liquid feeding pump is reduced enters the section where the solenoid valve is switched, or the liquid feeding speed of the liquid feeding pump is reduced when switching the solenoid valve so as to straddle. After that, it is possible to perform the control for performing the suction from the B solenoid valve 53 at the low speed without returning to the normal speed. Also in the case of such control, as in the example of FIG. 8, the time ratio of the section td in which variation occurs when switching the solenoid valve can be relatively lowered, and the accuracy of the mixture ratio control can be improved. Can do.

  FIG. 10 shows a fifth example of the relationship between the operation of the solenoid valve according to the embodiment of the present invention and the liquid feed pump liquid feed speed. The control shown in this figure can also be performed as another countermeasure when the opening time of the B solenoid valve 53 is short and the speed change of the liquid feed pump cannot catch up. That is, after the liquid feeding speed of the liquid feeding pump is reduced at the time of switching of the B solenoid valve 53, it is returned to a speed lower than the normal speed without returning to the normal speed, and the suction from the B solenoid valve 53 is performed. Control may be performed. Even in such a control, since the opening time of the B solenoid valve 53 can be made longer than the case of the liquid feed speed of a normal liquid feed pump, the time of the section td having a variation when switching the solenoid valve. This ratio can be lowered relatively, and the accuracy of the mixing ratio control can be improved.

  In this embodiment, the description has been made that the liquid feeding speed of the liquid feeding pump is reduced. However, in order to obtain the same effect, control is performed so as to increase the liquid feeding speed of one liquid feeding pump. May be performed.

  As described above, according to the present embodiment, when the control of the mixing ratio is performed with higher accuracy, the operation control of the liquid feeding pump according to the operation status of the electromagnetic valve is performed, resulting in the variation in the operation of the valve. By reducing the variation amount of the flow rate, a more accurate mixing ratio can be realized, and a highly accurate liquid chromatograph pump and liquid chromatograph apparatus can be provided.

  Next, a liquid feeding device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 11 shows the overall configuration of the liquid delivery device according to the third embodiment of the present invention.

  The configuration of the liquid delivery device according to the third embodiment is the same as that of the second embodiment in many parts. Hereinafter, only the part which becomes a different structure from the liquid feeding apparatus which concerns on 2nd embodiment is demonstrated.

  A multi-channel switching valve 8 is installed in the downstream of the discharge pipe 7 and controls the connection between the discharge pipe 7 and one of the flow paths α, β, and γ, as shown in the figure. That is, the flow path for flowing the liquid delivered from the liquid feed pump is switched. Here, the multi-channel switching valve 8 is not an essential configuration that switches the three channels as shown in the figure, and may be a valve that switches inflow into the two channels. For example, a configuration in which the switching operation of connecting the discharge pipe and the α flow path and connecting the β flow path and the γ flow path may be combined.

  Here, in order to simplify and explain the operation of the multi-channel switching valve 8, it is limited to the case where the discharge pipe 7 and the α channel are connected and the case where the discharge pipe 7 and the β channel are connected, respectively, FIG. FIG. 13 shows a schematic cross-sectional view of the multi-channel switching valve 8. The multi-channel switching valve 8 switches the channel by moving the valve body 8B relative to the valve body 8A. Here, in order to prevent liquid leakage from the sliding portion and seal the liquid, the valve body 8B is pressed against the valve body 8A using the biasing spring 8C. As described above, since the leakage from the gap is sealed by applying pressure, the sliding resistance increases when the pressure of the liquid flowing through the multi-channel switching valve increases, and the operation of the valve body 8B. May become dull. Therefore, smooth operation of the valve body 8B cannot be performed, and the switching control of the liquid feeding from the liquid feeding pump is deteriorated due to the delay in switching of the valve due to the delay of the valve operation, that is, the variation, and the accuracy of the liquid feeding flow control is deteriorated. There is a concern that will decrease.

  The state of the liquid feed pump operation in this embodiment is shown in FIG. By the above switching operation, the flow area changes, and the connection flow path between the discharge pipe and the α flow path is expressed as α, and the connection flow path between the discharge pipe and the β flow path is expressed as β, as shown in FIG. It becomes.

  In the liquid feeding pump operation according to the present invention, the operation of the liquid feeding pump is started after the α channel is sufficiently opened, and after the operation is stopped, the α channel is closed. Next, the operation of the liquid feeding pump is started after the β channel is sufficiently opened, and after the operation is stopped, the β channel is closed.

  Further, as shown in FIG. 11, when there is a multi-flow path switching valve 8 on the discharge side, the reverse operation of the liquid feed pump is performed so that the pressure of the discharge pipe is lowered before the flow path is switched. Is going. Since the discharge pressure is lowered by the reverse operation, the switching of the liquid feeding by the multi-channel switching valve 8 is not deteriorated, and the deterioration of the precision of the liquid feeding control can be prevented.

  In addition, although the example which performs the operation | movement which reverses a liquid feeding pump was shown in a present Example, depending on the specification of an apparatus, it is good also as control which reduces speed, without performing until reverse. In addition, the liquid feeding pump does not necessarily have to be stopped in the valve element switching section.

  As described above, according to the present embodiment, in the liquid feeding device in which the electromagnetic valve and the liquid feeding pump are combined, even when the solenoid valve is on the discharge side, the liquid feeding liquid pump according to the operation status of the electromagnetic valve. By performing this operation control, it is possible to reduce the amount of flow variation and pressure fluctuation caused by variation in valve operation.

  Next, a fourth embodiment according to the present invention will be described. In the present embodiment, the liquid feeding control of the liquid feeding device is performed based on the operation of a valve that switches the flow path after injecting the sample onto the mobile phase flow path. Further, the present embodiment is not limited to the control of the low-pressure gradient liquid feeding as in the first to third embodiments, and includes one that is performed only by the operation of the liquid feeding pump main body as the liquid feeding device.

  FIG. 18 shows the positional configuration of the channel switching valve when the sample introduction channel is connected, when the channel is switched, and when the analysis channel is connected. As shown in this figure, from the state where the groove provided in the valve body is connected to the sample introduction flow path, it is connected to the analysis flow path through a switching operation by rotation. Here, since the groove of the flow path switching valve is closed during the switching operation (about 100 to 300 ms), no liquid flows from the liquid feed pump side to the analysis flow path. Then, immediately after connection with the analysis channel, a phenomenon occurs in which the liquid flows in a state where the pressure of the liquid is increased.

  FIG. 19 is an overall configuration diagram of an autosampler (sample injection unit) in the liquid chromatograph according to the present embodiment.

  The sample is weighed by the syringe 20 through the needle 22. The needle 22 is connected to the injection port 23, and the sample is injected into the flow path switching valve 24 side. The injected sample is introduced into the sample introduction channel in the channel switching valve 24. By switching the flow path switching valve 24, the sample introduction flow path is switched to the analysis flow path (the downstream flow from the column 15), and the sample is introduced to the column side.

  When a column used in a liquid chromatograph is used at a pressure higher than the upper limit of pressure, the packing material packed therein deteriorates, resulting in a decrease in separation performance and a shortened life. Therefore, in order to use the column for a longer period of time, it is necessary to make the pressure of the liquid discharged from the liquid feed pump and reaching the analysis flow path be in a range not exceeding the upper limit of the column pressure.

  FIG. 20 shows that the liquid feed pump and the autosampler according to the present embodiment are connected by a signal cable and synchronized. The synchronization signal can be output from either the liquid feed pump 12 or the autosampler 13, and can be synchronized by supplying the output signal to the other in accordance with one cycle.

  FIG. 21 is a diagram showing the relationship between the operation of the flow path switching valve 24 and the liquid feeding speed of the liquid feeding pump 12 in the present embodiment. As shown in the figure, the liquid feed pump 12 starts the operation of reducing or stopping the liquid feed speed by reducing the rotation speed of the motor. The sampler 13 starts the operation of switching the flow path switching valve 24 from the sample introduction flow path to the analysis flow path.

  Since the time required for switching the flow path is determined by the type of valve to be used and the control method by the control unit 1509, the time for the liquid feeding pump to decelerate the liquid feeding speed is input based on the switching time.

  FIG. 22 shows that the operation of stopping the motor of the liquid feeding pump 12 is performed during the switching of the flow path switching valve 24 by outputting a synchronization signal from the autosampler 13 to the liquid feeding pump 12. When the switching operation of the flow path switching valve 24 is started, a synchronization signal is output from the autosampler 13 to the liquid feeding pump 12, and the motor of the liquid feeding pump 12 responds to the output by a predetermined pulse rate (9600 [pps here). ]) Is changed from the operating state to the stopped state (0 [pps]). Thereby, in the section of the change concerned, since liquid feeding pump 12 is not performing further liquid feeding, it can prevent an increase in pressure.

  FIG. 23 shows that the motor of the liquid feed pump 12 is gradually decelerated and stopped during the switching of the flow path switching valve 24 by outputting a synchronization signal from the autosampler 13 to the liquid feed pump 12. Is shown. In the example of FIG. 22, under a high pressure condition of 140 [MPa], it is difficult from the aspect of the motor torque performance to instantaneously stop the operation from the pulse rate during operation in the section. Therefore, as shown in the figure, the motor is gradually decelerated from a predetermined pulse rate (here, 9600 [pps]) to 0 [pps] and then gradually accelerated again to the pulse rate before the change. Like that. By adopting such control, it is possible to prevent an increase in the fluid pressure when the flow path switching valve 24 is switched while suppressing a burden on the motor of the liquid feeding pump 12.

  FIG. 24 shows that by outputting a synchronization signal from the autosampler 13 to the liquid feed pump 12, the operation of decelerating without stopping the motor of the liquid feed pump 12 is performed during the switching of the flow path switching valve 24. Show. In the case where it is difficult to completely stop the liquid feed pump 12 due to the relationship between the torque performance of the motor of the liquid feed pump 12 and the switching time, as shown in FIG. It is also possible to only decelerate the pulse rate of the motor. Also by this control, it is possible to prevent an increase in fluid pressure when the flow path switching valve 24 is switched while suppressing a burden on the motor of the liquid feeding pump 12.

  FIG. 25 shows the pressure detected by the liquid feed pump 12 when the liquid feed pump control method according to the present embodiment is applied / applied. In the case where this embodiment is not applied, it can be seen that the pressure continues to increase as shown in the above figure because the motor continues to operate at the set pulse rate even during the switching operation of the flow path switching valve 24. On the other hand, when the above-described control method was applied, the increase in the pressure of the liquid feed pump 12 could be significantly reduced.

  FIG. 26 shows the pressure detected at the column inlet when the liquid pump control method according to the present embodiment is applied / applied. As shown in FIG. 25, since the increase in pressure in the liquid feed pump 12 is applied to the column inlet, according to the present invention, the increase in pressure applied to the column can also be suppressed.

  As described above, according to the present embodiment, it is possible to reduce the pressure increase of the liquid feed pump and the column due to the characteristics of the flow path switching valve when introducing the sample in the autosampler, so that it is possible to realize high-precision liquid feed control, In addition, deterioration of the column can be prevented and analysis accuracy can be increased.

DESCRIPTION OF SYMBOLS 1 ... Liquid feeding control part 2A ... 1st actuator 3A ... 2nd actuator 2C ... 1st cylinder 3C ... 2nd cylinder 2CV ... 1st check valve 3CV ... second check valve 2P ... first plunger 3P ... second plunger 8A ... valve body 8B ... valve body 8C ... biasing spring 43 ... A Solenoid valve 53 ... B solenoid valve 7 ... discharge pipe 8 ... multi-channel switching valve 8A ... valve body 8B ... valve body 10 ... sample introduction channel 11 ... analytical flow Channels 12, 94 ... liquid pumps 13, 1503 ... autosampler (sample injection part)
15, 1504 ... column (analysis section)
19 ... Sample bottle 20 ... Syringe 21 ... Buffer tube 22 ... Needle 23 ... Injection port 24 ... Flow path switching valve 25 ... Waste liquid 91 ... Liquid feed tank 92- ··· Suction channel 93 ··· Solenoid valve 95 ··· Actuator 1501 ··· Liquid chromatograph portion 1502 ··· Liquid feeding device (liquid feeding portion)
1505 ... Detector (detector)
1506 ... Input device 1507 ... Data processing device 1508 ... Output device 1509 ... Control unit 1701 ... Electric circuit 1702 ... Solenoid 1703 ... Valve element 1704 ... Hall element 1705 ..Detection electric circuit

Claims (11)

A liquid feeding section for feeding a liquid;
A valve that is disposed on the flow path of the liquid fed from the liquid feeding section and performs an opening and closing operation;
A liquid feeding device for a liquid chromatograph comprising the liquid feeding unit and a control unit for controlling the operation of the valve,
Based on the timing of the opening and closing operation of the valve, the control unit,
A liquid feeding device for a liquid chromatograph , wherein operation of the liquid feeding unit is controlled so as to change a speed at which the liquid feeding unit feeds a liquid. In the liquid chromatograph liquid feeding device according to claim 1,
Based on the timing of the opening and closing operation of the valve, the control unit,
Speed said liquid feed unit for feeding the liquid, the valve is in so that such slower than feeding speed in the open state, feeding liquid chromatograph and controls the operation of the liquid supply portion Liquid device. In the liquid chromatograph liquid feeding device according to claim 1,
The liquid feeding part is a pump for sucking a plurality of types of liquids,
The valve is arranged at least two on the suction side of the pump, and is configured to be able to switch the type of liquid sucked by the pump by opening and closing operations,
The controller is
And when one of the valve starts to transition from the open state to the closed state, and when the other finishes transition from a closed state to an open state, based on the rate at which the pump for feeding the liquid, the A liquid chromatograph liquid feeding device, characterized in that the operation of the pump is controlled such that the valve is slower than the liquid feeding speed in the open state. In the liquid chromatograph liquid feeding device according to claim 3 ,
The controller is
At least before the timing at which one of the valves starts to transition from the open state to the closed state and after the timing at which the other ends the transition from the closed state to the open state, the liquid feed pump is liquid. The liquid chromatograph liquid feeding device controls the operation of the pump so that the liquid feeding speed is lower than the liquid feeding speed when the valve is open . In the liquid chromatograph liquid feeding device according to claim 3 ,
The control unit determines a flow rate of each liquid among a plurality of types of liquid sucked by the pump,
Based on the determined flow rate, the liquid feeding speed of the pump when each corresponding valve is in the open state, and before the timing at which one of the valves starts transition from the open state to the closed state, the other There liquid transfer device for a liquid chromatograph, wherein Rukoto seek feed rate of the pump until after the timing to be completely transition from a closed state to an open state. A liquid feed pump that sucks and discharges liquid;
A flow path switching valve that is disposed on the discharge side of the liquid feed pump and switches a plurality of flow paths of the discharged liquid;
In the liquid feeding device for a liquid chromatograph comprising the liquid feeding pump and a control unit that controls the operation of the flow path switching valve ,
The controller is
Either or both while the flow path switching valve is transitioning from the closed state to the open state, or while the flow path switching valve is transitioning from the open state to the closed state,
Control to liquid transfer device for a liquid chromatograph, wherein Rukoto to vary the feed rate of the liquid feed pump. In the liquid chromatograph liquid feeding device according to claim 6 ,
The controller is
Either or both while the flow path switching valve is transitioning from the closed state to the open state, or while the flow path switching valve is transitioning from the open state to the closed state,
Wherein the so that a low discharge pressure of the flow path switching valve, the liquid feed liquid chromatograph liquid transfer apparatus characterized by controlling the operation of the pump. In the liquid chromatograph liquid feeding device according to claim 1 ,
A sensor for detecting an open / closed state of the valve;
The controller is
A liquid chromatograph liquid feeding device that controls an operation of the liquid feeding unit based on a detection result of the sensor . A liquid feeding section for feeding a liquid;
A valve that is disposed on the flow path of the liquid fed from the liquid feeding section and performs an opening and closing operation;
A liquid chromatograph device comprising: the liquid feeding unit; and a control unit that controls the operation of the valve,
Based on the timing of the opening and closing operation of the valve , the control unit,
The way feeding unit alters the speed of feeding the liquid, the liquid chromatograph Fuso location, characterized by controlling the operation of the liquid supply portion. A liquid feeding part for feeding the mobile phase;
A sample injection portion for injecting a sample into the liquid phase mobile phase flow path,
A flow path switching valve for switching the mobile phase flow path containing the injected sample;
A separation unit for separating components in the injected sample;
A detection unit for detecting the separated sample components;
A liquid chromatograph apparatus comprising: the liquid feeding unit , the sample injection unit, the flow path switching valve, the separation unit, and a control unit that controls the operation of the detector ,
The control unit , based on the timing when the flow path switching valve switches the mobile phase flow path,
A liquid chromatograph apparatus for controlling an operation of the liquid feeding section. The liquid chromatograph apparatus according to claim 10 ,
The flow path switching valve is
After injection of the sample, the liquid supply portion and the liquid chromatograph and wherein the Rukoto switched mobile phase flow path so as to connect the separation unit.