JPH07332227A - Drive control device for plunger reciprocating type pump - Google Patents

Abstract

PURPOSE:To improve flow rate precision by a method wherein given correction is applied on the gear shift pattern of a produced eccentric cam by a detecting pressure and a detecting displacement amount and based on a correcting gear shift pattern, a motor drive signal is produced, and an eccentric cam is rotated. CONSTITUTION:The pressure of a pump 11a (11b) is detected by a pressure sensor and a displacement amount of a constant velocity pattern producing part 41 produces and stores the constant velocity pattern of an eccentric cam 24 for reciprocating the plunger 23. When the eccentric cam 24 is rotated at a constant velocity, based on detecting information from the two sensors, a gear shift pattern is corrected by a fundamental clock pattern producing part 44 according to the rotary angle of the eccentric cam 24. When the eccentric cam 24 is rotated in a correcting gear shift pattern, acceleration is corrected by a correction pattern producing part 48 during suction at a part corresponding to the suction stroke of a pump 11A (11B) so that a detecting pressure is rendered constant. The correcting gear shift pattern is outputted to a driver 49 to rotate the eccentric cam 24. This constitution improves processing precision and reduces cost without forming the eccentric cam in a complicated shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a plunger reciprocating pump, and more particularly, a drive control for driving and controlling a plunger reciprocating pump so as to stably deliver a constant flow rate liquid within a working liquid pressure range. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, a plunger reciprocating pump is
It is used as a liquid feed pump for a liquid chromatography system, for example, where a liquid feed at a constant flow rate is required.
This type of plunger reciprocating pump includes the following. (1) Reciprocating type: As shown in FIG. 6, a pump head 1 provided with check valves 2a and 2b at the liquid suction (suction) part and the liquid discharge part, respectively, and the pump head 1 slidably in the axial direction. A plunger 3 which is inserted and changes the pressure in the pump head 1 by the reciprocating motion in the axial direction thereof;
An eccentric cam 4 that slides (linearly moves) the plunger 3 in the axial direction, and a motor 5 that rotates the eccentric cam 4 at a constant speed.
Is a plunger reciprocating pump provided with, and by adjusting the return amount of the plunger 3 by the stroke adjusting screw 6, the stroke length of the plunger 3 is mechanically changed to change the flow rate. ing. Reference numeral 7 denotes a return spring compressed between the pump head 1 and the plunger 3. This reciprocating type plunger reciprocating pump has a simple structure, and if the pressure is the same, the flow rate accuracy is high, The operation of the check valves 2a and 2b is also stable.

(2) Quick return type: As shown in FIG. 7, a non-circular eccentric cam 8 is used. The eccentric cam 8 is driven by the motor 5 at a constant speed, and the eccentric cam 8 has a cam profile. Accordingly, the plunger 3 is accelerated when the liquid suction is started and when the liquid suction is completed. This tie return type plunger reciprocating pump can reduce the pulsation of the discharge liquid pressure.

(3) Dual type: There are a parallel type and a series type. In the parallel type, as shown in FIG. 8, the single motor 9 rotates the cams 8A and 8B of the same shape, which are 180 degrees out of phase with each other, and the two plungers 3A and 3B are rotated.
The plungers 3A and 3B are alternately operated so that one of B is in the suction stroke and the other is in the discharge stroke, and the pulsation of the discharge side hydraulic pressure is reduced by the continuous discharge operation. Further, as shown in FIG. 9, the in-series type is a first type in which check valves 2a and 2b for suction and discharge are provided.
The pump head 1A is connected to the second pump head 1B having a capacity of ½ of that capacity and having no check valve, and the plungers 3A and 3B fitted in both pump heads 1A and 1B are slidable in the axial direction. By driving with a 180 degree phase shift, the second pump head 1B functions as a damper, and the pulsation of the discharge side hydraulic pressure is reduced.

[0005]

However, the above-mentioned conventional plunger reciprocating pumps of each type have the following problems. (1) In the reciprocating type, since the pulsation of the discharge side hydraulic pressure becomes large, an effective pressure damper is required outside.

(2) In the quick return type, the operation of the check valves 2a and 2b tends to be unstable because the plunger 3 moves rapidly when switching between suction and discharge. Further, since the cam 8 has a complicated shape and is required to have high processing accuracy, the cost is inevitably high. (3) In the dual type, the cam pattern is complicated because the cams 8A and 8B are shaped so as to reduce the pulsation of the discharge side hydraulic pressure when switching between the suction stroke and the discharge stroke. The theoretically required accuracy cannot be sufficiently satisfied due to the difficulty of.

That is, in the conventional plunger reciprocating pump, since the cams have complicated cam driving plungers 8A and 8B in order to suppress the pulsation of the discharge liquid pressure, the cams 8A and 8B are used. There is a problem that the machining of 8B is difficult and that the pump performance (particularly the flow rate accuracy) is greatly affected by the cam machining accuracy. Therefore, the present invention uses a simple eccentric cam having a cam shape capable of high-precision machining, and drives the eccentric cam so as to move the plunger at a substantially constant speed (rotational speed control). It is an object of the present invention to realize a drive control device for a plunger reciprocating pump that sufficiently satisfies the required pump performance.

[0008]

To achieve the above object, the present invention is directed to rotating a plurality of eccentric cams at different phases by a single motor to engage a plurality of plungers engaged with the eccentric cams at different timings. In addition to reciprocating in one direction, liquid is sucked into the suction part when each plunger moves in one direction, and liquid is discharged from the discharge part when moving each plunger in the other direction for continuous discharge operation. A device for driving and controlling a plunger reciprocating pump, comprising: pressure detecting means for detecting the discharge pressure of the plunger reciprocating pump; the eccentric cam corresponding to the rotation angles of the plurality of eccentric cams; and the plan. A displacement amount detecting means for detecting the displacement amount of the contact point with the jar or holding the displacement amount as stored data, and the plurality of plungers by the motor under a predetermined speed condition. A shift pattern creating means for creating a shift pattern of the eccentric cam for the backward movement, a pattern storing means for variably storing the shift pattern created by the shift pattern creating means, and a predetermined discharge load condition for storing the shift pattern. When the eccentric cam rotates at a constant speed, the shift stored in the pattern storage means is set so that the plunger moves at the predetermined speed condition based on the detection information of at least one of the pressure detection means and the displacement amount detection means. First correction means for correcting and changing a pattern according to the rotation angle of the eccentric cam, and when the eccentric cam rotates under a predetermined discharge load condition with a unique gear shift pattern corrected by the first correction means , The shift pattern stored in the pattern storage means is set so that the detection value of the pressure detection means becomes substantially constant. Second to acceleration correction at the portion corresponding to the time of suction and discharge switching of reciprocating Dogata pump
Correction means and a motor drive signal corresponding to the shift pattern stored in the storage means, and the motor is driven by the motor drive signal to drive the plurality of eccentric cams to shift the speed stored in the pattern storage means. A motor drive circuit that rotates in a pattern is provided, and the invention according to claim 2 is such that the movement of the plunger under a predetermined speed condition is substantially the same as the reference speed of the plunger. The feature is that the movement is at a constant speed.

By the storage means, a plurality of shift patterns corresponding to different discharge hydraulic pressures or different discharge loads can be stored so that a constant flow rate of liquid can be constantly fed even in different hydraulic pressure regions. Also, the motor is
For example, a pulse motor, in which case the first correction means is at least one of the pressure detection means and the displacement amount detection means when the eccentric cam rotates at a constant speed at a predetermined speed under a predetermined discharge load condition. The pulse rate of the pulse motor is changed so that the plunger moves under the predetermined speed condition based on the detection information of the displacement of the contact point between the eccentric cam and the plunger during one rotation of the eccentric cam. It is preferable to correct the pattern.

[0010]

According to the present invention, the shift pattern of the eccentric cam for reciprocating the plunger under the predetermined speed condition is created by the shift pattern creating means, and the shift pattern is stored in the pattern storing means so as to be changeable. Meanwhile,
When the eccentric cam rotates at a constant speed under the specified discharge load condition,
Based on the detection information of at least one of the pressure detection unit and the displacement amount detection unit, the first correction unit corrects and changes the shift pattern according to the rotation angle of the eccentric cam so that the plunger moves under the predetermined speed condition. It Further, when the eccentric cam rotates under the predetermined discharge load condition with the shift pattern corrected by the first correcting unit, the shift pattern by the second correcting unit is set so that the detection value of the pressure detecting unit becomes substantially constant. Is accelerated and corrected at the portion corresponding to the suction stroke of the plunger reciprocating pump. Then, the motor drive circuit drives the motor corresponding to the shift pattern, and the eccentric cam rotates in the shift pattern. Therefore, the deviation of the displacement pattern of the plunger due to the dimensional error of the eccentric cam can be corrected accurately in the actual load state, and the flow rate accuracy of the pump is improved. Further, it is not necessary to form the eccentric cam into a complicated shape corresponding to a complicated shift pattern, and it is possible to improve the processing accuracy of the eccentric cam and reduce the cost. Further, by driving a plurality of plungers by a plurality of eccentric cams, a continuous discharge operation is performed, and pulsation is prevented by acceleration correction during suction / discharge switching. Therefore, it is possible to perform liquid delivery with excellent flow rate accuracy by continuous discharge operation and suppression of pressure fluctuation during suction / discharge switching.

Further, according to the second aspect of the present invention, since the movement of the plunger under the predetermined speed condition is the movement at a substantially constant speed at the reference speed, the constant flow rate liquid feeding accompanied with the above-mentioned operation is performed. be able to.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 5 are views showing an embodiment of a drive control device for a plunger reciprocating pump according to the present invention, showing an example in which the present invention is applied to a small-sized portable type liquid chromatography system. .

First, the structure will be described. FIG. 1 is a diagram showing the overall configuration of the liquid chromatography system. In FIG. 1, 11 is a dual-type plunger reciprocating means for sucking and discharging a predetermined liquid (developing solvent not shown) from a liquid source not shown. Dynamic pump, 12 is a passage type pressure sensor (pressure detecting means) for detecting the pressure of the liquid discharged from the plunger reciprocating pump 11, and 13 is a sample mixture in the liquid on the downstream side of the pressure sensor 12. Is a column oven having a container 14a and a column 14b arranged therein, and 15 is a detector. Injector 13, column oven 14 and detector 15
Are well-known, and the column 14 of the column oven 14
A predetermined adsorbent is incorporated in b. Then, the mixed sample injected from the injector 13 into the liquid is separated, for example, in the column oven 14 using the strength of the adsorptivity, and is introduced into the detector 15 in order from the weakest adsorptive component.
The process itself of such liquid chromatography is the same as the conventional one.

The plunger reciprocating pump 11 comprises a pair of pump units 11a and 11b.
As shown in FIG. 3, a and 11b are a liquid suction part 21a provided with a check valve 22a and a liquid discharge part 21b provided with a check valve 22b.
And a pump head 21 having an end portion 23a slidably fitted into the pump head 21 through a plunger seal 21c in the axial direction, and reciprocally moved in the axial direction (for example, a reciprocating motion of a stroke of 2 mm) inside the pump head 21. A plunger 23 that changes the pressure of the liquid, and a cam surface 24 that is engaged with the plunger 23 and is eccentric with respect to a rotation center shaft 24a having a predetermined large diameter.
a substantially circular eccentric cam 24 having b and rotating about its rotation center axis, a pump head 21 and a plunger.
It is provided with a return spring 25 compressed between 23. The check valves 22a and 22b use, for example, 1/16 inch balls. The rotation center shaft 24a of the eccentric cam 24 of both pump units 11a and 11b is coaxially coupled, and a single pulse motor 27 (for example, a stepping motor) is coupled to the rotation center shaft 24a via a timing belt 26. ing. Further, the eccentric cam 24 can cooperate with the return spring 25 to reciprocate the plunger 23 in the axial direction.

Further, the plunger reciprocating pump 11 is
The pair (plurality) of eccentric cams 24 are rotated by the pulse motor 27 in different phases, the pair of plungers 23 engaged with the eccentric cams 24 are axially reciprocated in opposite phases (different timings), and each plunger is reciprocally moved. When the plunger 23 moves in one direction, the liquid is sucked into the suction part 21a, and when the plunger 23 moves in the other direction, the liquid is discharged from the discharge part 21b to perform a continuous discharge operation.

A control unit 30 controls the operations of the plunger reciprocating pump 11, the column oven 14 and the detector 15. The control unit 30 sets various set value information or selects an operation mode. The operation unit 29 for is connected. As shown in FIG. 2, the control unit 30 includes a CPU 31, RO
M32, RAM33, motor driver 34, sensor amplifier 3
5, the A / D converter 36 and the like are included, and the pressure sensor 12, the pulse motor 27, the power supply 37, and the position sensor 38 are connected to the control unit 30. CPU31
For example, it consists of a 16-bit microcomputer,
In order to change the pulse rate supplied to the pulse motor 27 according to the amount of displacement of the plunger, a pulse rate pattern is created on the memory by using a real-time output, a timer, and a DMA (Direct Memory Access) function. Therefore, the pulse rate can be changed without the intervention of a microcomputer program.

The position sensor 38 is a displacement amount detecting means for detecting the displacement amount of the plunger 23 corresponding to the rotation angle of the eccentric cam 24, that is, the displacement amount of the contact point between the eccentric cam 24 and the plunger 23. , This sensor 38 is
It may be separated from. In that case, the displacement amount is measured in advance at the manufacturing stage and the measured data is RO
By storing it in M32, the position sensor 38 can be made unnecessary when the actual liquid is fed.

FIG. 3 shows a CPU 31, a ROM 32 (storage means).
FIG. 3 is a functional block diagram of a RAM 33 (storage means). In the figure, 41 is a constant velocity pattern creating unit that creates a constant velocity pattern (each pattern will be described later) for rotating the eccentric cam 24 at a constant velocity, and 42 is an eccentric cam based on the detection information of the position sensor 38. This is a basic cam displacement pattern creation unit including a PROM that creates and stores a cam displacement pattern in consideration of mechanical dimension errors and the like in 24. Further, 43 is a cam constant-speed rotation pressure pattern creation unit that creates a pressure pattern based on the pressure detected by the pressure sensor 12 when the eccentric cam 24 is rotated at a uniform speed under actual load conditions, and 44 is a basic cam. This is a basic clock pattern creation unit that performs a comparative calculation of the data of the displacement pattern and the pressure pattern during constant speed rotation of the cam, and creates a basic clock pattern for driving and controlling the pulse motor 27 so as to obtain the uniform motion of the plunger 23. . The basic clock pattern creation unit 44 is a shift pattern creation unit that creates a shift pattern of the eccentric cam 24 for calculating the reciprocating movement of the plunger 23 at the reference speed to a substantially constant speed (under a predetermined speed condition) by the pulse motor 27. In addition, it also functions as first pattern storage means for storing the calculated theoretical shift pattern (clock pattern in this case) in the memory.

Further, the basic cam displacement pattern creating section 42, the cam constant speed rotation time pressure pattern creating section 43 and the basic clock pattern creating section 44 are the cam rotation clock pattern creating section.
When the pulse motor 27 operates according to the drive pulse from 46 and the eccentric cam 24 rotates at a constant speed under a predetermined discharge load condition,
For example, 400 points of pressure data are always collected per revolution of the eccentric cam 24, and the patterns for the past 5 revolutions are stored in the memory. With this data, an acceleration correction data table described below and self-learning processing are performed. Further, the basic clock pattern creation unit 44, based on the detection information of at least one of the pressure sensor 12 and the position sensor 38, so that the plunger 23 moves at a substantially constant speed at a predetermined speed (moves at a predetermined speed condition), It also functions as a first correction unit that corrects and changes the stored theoretical basic clock pattern according to the rotation angle of the eccentric cam 24.

The clock pattern created and corrected by the basic clock pattern creation unit 44 is given to the flow rate value corresponding clock creation unit 45. Then, the flow-rate-corresponding clock generation unit 45 performs proportional calculation in accordance with the set flow-rate value of the system to generate a clock pattern corresponding to the set flow-rate value. The clock pattern created by the flow rate value corresponding clock creating unit 45 and the constant velocity pattern created by the constant velocity pattern creating unit 41 are stored in the cam rotation clock pattern creating unit 46, respectively. That is, the cam rotation clock pattern creating section 46 constitutes a second pattern storing means for variably storing the shift pattern corrected by the basic clock pattern creating means 44 which is the first correcting means.

Further, the cam rotation clock pattern creating section 46
Can send a clock corresponding to the stored shift pattern to the motor driver 49 to drive the pulse motor 27 with the shift pattern stored at that time. Specifically, the pulse motor 27 is driven to rotate the eccentric cam 24 at a constant speed based on the constant speed pattern from the constant speed pattern creating section 41, or based on the clock pattern from the flow rate value corresponding clock creating section 45. The pulse motor 27 can be driven so as to reciprocate the plunger 23 at a substantially constant speed.

When the eccentric cam 24 rotates in a gear shift pattern corrected by the basic clock pattern 44 under a predetermined discharge load condition, 47 creates a pressure pattern during steady rotation based on the detection value of the pressure sensor 12. Reference numeral 48 denotes a pressure pattern creation unit during steady rotation, in which the shift pattern stored in the cam rotation clock pattern creation unit 46 is sucked by the plunger reciprocating pump so that the detection value of the pressure sensor 12 becomes substantially constant. It is a suction-time correction pattern creation unit as a second correction means for performing acceleration correction (details will be described later) so that the portion corresponding to the discharge switching is rotated at the maximum speed.

The motor driver 49 also generates a motor drive signal corresponding to the clock pattern stored in the cam rotation clock pattern generator 46, and drives the pulse motor 27 by the motor drive signal to drive the plurality of eccentric cams 24. The cam rotation clock pattern creating section 46 is adapted to rotate in the gear shift pattern stored therein. The displacement amount of the plunger 23 corresponding to the rotation of the eccentric cam 24, that is, the displacement amount of the engaging portion between the plunger 23 and the eccentric cam 24 in the axial direction of the plunger 23 can be approximated by the following equation. it can.

Displacement amount = A (1-COSφ) (where φ is the rotation angle of the eccentric cam) When the displacement is calculated by dividing the half rotation of the eccentric cam 24 into 200, the minimum displacement = 0.000123 mm, the maximum displacement = When the moving speed of the plunger 23 is 1 mm / sec, the minimum displacement pulse rate is 123 μsec and the maximum displacement pulse rate is 15707 μsec. Also, if the pulse motor 27 is driven in 8 divisions, one cam rotation will become 6400 pulses, and the pulse rate table requires 12800 bytes (4
1 bit output with a bite, half rotation pattern with 3200 pulses). In order to use the same clock for every 200 divisions, 32 data must be the same. From the above reference data, the pulse rate pattern for each flow rate can be calculated and created by proportional calculation.

Next, the operation will be described. First, the basic operation of the plunger reciprocating pump 11 will be described with reference to FIG.
When the eccentric cam 24 is rotated at a constant speed as shown in (b), the plunger 23 has a displacement pattern as shown in FIG. 4 (a), but at the rotation speed as shown in FIG. 4 (d). Eccentric cam
When 24 is rotated, as shown in Fig. 4 (c), the plunger
The displacement speed of 23 can be made substantially constant.

In this embodiment, in order to suppress the pressure pulsation on the discharge pressure side, the moving speed of the plunger 23 is made substantially constant by controlling the rotation speed of the eccentric cam 24. For that purpose, the discharge pressure is fed back. Instead, the control is performed so as to create a pressure pattern by feeding the test liquid to minimize the width of the pulsation. When sending this test solution, first,
The reference discharge load and the cam rotation speed are set by an input operation from, while the constant-speed pattern creating unit 41 gives a constant-speed pattern to the cam rotation clock pattern creating unit 46, and the pulse motor is supplied via the motor driver 49. By driving 27, the pair of eccentric cams 24 of the plunger reciprocating pump 11 rotate at a constant speed in opposite phases under a predetermined discharge load condition, and based on the detection information of the position sensor 38 at that time. A basic cam displacement pattern creating unit 42 creates a basic cam displacement pattern as shown in FIG. Further, the pressure sensor 12 when the eccentric cam 24 is rotated at a constant speed under the discharge load (actual load) condition on the basis of the theoretical pattern calculated by the basic clock pattern creation unit 44.
The detected pressure data of is collected, and the collected data is shown in FIG.
A pressure pattern as shown in (b) is created by the pressure pattern creating unit 43 during constant-speed rotation of the cam.

Next, based on the pressure pattern, the average pressure value excluding the pressure value around the time of switching between suction and discharge, the actual pressure value, and the unique displacement of each pump unit 11a, 11b which is detected or stored in advance. By comparing the patterns (basic cam displacement patterns), a clock pattern for one rotation of the eccentric cam 24 is created, and an operation clock pattern in which the response delay of pressure is corrected in the cam rotation direction is created. It is stored in the memory of the clock pattern creating unit 44. That is, the basic clock pattern creation unit 44 performs the correction processing of the pulse rate according to the mechanical error of the eccentric cam 24 and the creation of the basic clock pattern which is the shift pattern. The pressure pattern at the time of steady rotation created and stored here is as shown in FIG. 5 (d).

Next, the basic clock pattern is adjusted by the flow rate value corresponding clock generation unit 45 so as to correspond to the flow rate value of the system, and then stored in the cam rotation clock pattern generation unit 46. Next, the cam rotation clock pattern creation unit 46
Based on the clock pulse stored in the motor driver 49
The pulse motor 27 is driven by this, and the eccentric cam 24 rotates steadily. At this time, based on the detection information of the pressure sensor 12, a pressure pattern at the time of steady rotation (at the time of eccentric cam shift rotation) as shown in FIG. 5D is created by the pressure pattern creating unit 47, and the discharge stroke and the suction stroke are made. By rotating the eccentric cam 24 at the maximum speed before and after the switching time and accelerating the plunger 23, the suction correction pattern as shown in FIG. It is created by the suction time correction pattern creation unit 48.

At the time of actual liquid feeding, based on the clock pattern 2 stored in the cam rotation clock pattern creating section 46,
The pulse motor 27 is drive-controlled so that a substantially constant pressure pattern as shown in (e) is obtained. Further, by changing the width of the acceleration correction region at the time of switching the suction / discharge, the fixed amount liquid is fed at the set flow rate even in different pressure regions.

As described above, in this embodiment, the deviation of the displacement pattern of the plunger 23 due to the dimensional error of the eccentric cam 24 or the like can be accurately corrected under the actual load condition, and the flow rate accuracy of the pump 11 is improved. Further, it is not necessary to form the eccentric cam 24 into a complicated shape corresponding to a complicated shift pattern, so that the processing accuracy of the eccentric cam 24 can be improved and the cost can be reduced. Further, by driving the plurality of plungers 23 by the plurality of eccentric cams 24, a continuous discharge operation is performed, and sufficient pulsation is prevented by acceleration correction during suction / discharge switching.
Therefore, it is possible to perform liquid delivery with excellent flow rate accuracy by continuous discharge operation and suppression of pressure fluctuation during suction / discharge switching.

Furthermore, since the movement of the plunger 23 under the predetermined speed condition is the movement at substantially the same speed at the reference speed, it is possible to carry out the constant-rate liquid transfer with the above-mentioned action. In this embodiment, a dual type plunger reciprocating pump having a single motor as a driving means is used, but this is for downsizing, and a plurality of motors are used according to the number of pump units. It goes without saying that it may be one.

[0032]

As described above, according to the present invention, the eccentric cam capable of high-precision machining is used, and the displacement pattern of the plunger due to the dimensional error of the eccentric cam is accurately corrected under the actual load condition. Therefore, the flow rate accuracy of the pump can be improved. Further, it is not necessary to form the eccentric cam in a complicated shape, and it is possible to improve the processing accuracy of the eccentric cam and reduce the cost. Further, by driving a plurality of plungers by a plurality of eccentric cams, a continuous discharge operation is performed, and pulsation is prevented by acceleration correction when switching between suction and discharge. Therefore, it is possible to perform liquid delivery with excellent flow rate accuracy by continuous discharge operation and suppression of pressure fluctuation during suction / discharge switching.

According to the second aspect of the present invention, since the movement of the plunger under the predetermined speed condition is a substantially constant speed movement at the reference speed, a more stable constant flow rate liquid feed having excellent flow rate accuracy is performed. be able to.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a liquid chromatography system showing an embodiment of a drive control device for a plunger reciprocating pump according to the present invention.

FIG. 2 is a block configuration diagram of a control unit according to an embodiment.

FIG. 3 is a control function block diagram including a pump according to an embodiment.

4A is a constant velocity pattern of the plunger of one embodiment, FIG. 4B is a constant velocity cam rotation speed and a constant velocity pattern of the plunger, and FIG. 4C is a constant velocity displacement of the plunger. The pattern, (d), shows the cam rotation speed corresponding to the constant velocity displacement pattern of the plunger.

5A is a constant velocity pattern of the plunger of one embodiment, FIG. 5B is a pressure pattern during constant velocity rotation, FIG. 5C is a constant velocity displacement pattern of the plunger, and FIG. 5D is a plunger. FIG. 8 is a diagram showing a pressure pattern during variable speed rotation of FIG.

FIG. 6 is a schematic view of a conventional reciprocating type plunger reciprocating pump.

FIG. 7 is a schematic view showing a conventional quick return type plunger reciprocating pump.

FIG. 8 is a schematic view of a conventional dual type parallel plunger reciprocating pump.

FIG. 9 is a schematic view of a conventional dual type in-line type plunger reciprocating pump.

[Explanation of symbols]

11 Plunger reciprocating pump 12 Pressure sensor (pressure detection means) 23 Plunger 24 Eccentric cam 27 Pulse motor (motor) 30 Control section 31 CPU 32 ROM (memory) 33 RAM (memory) 38 Position sensor (displacement amount detection means) ) 44 basic clock pattern creation section (shift pattern creation means, pattern storage means, first correction means) 48 suction time correction pattern creation section (second correction means) 49 motor driver (motor drive circuit)

Claims (2)

[Claims] 1. A plurality of eccentric cams are rotated in different phases by a motor to axially reciprocate a plurality of plungers engaged with the eccentric cams at different timings, and each plunger is moved in one direction. A device for driving and controlling a plunger reciprocating pump that sometimes sucks liquid into a suction unit and discharges liquid from a discharge unit when moving each plunger in the other direction, wherein: A pressure detection means for detecting the discharge pressure of the plunger reciprocating pump, and a displacement amount at the contact point between the eccentric cam and the plunger corresponding to the rotation angle of the plurality of eccentric cams, or the displacement amount. Is stored as stored data, and a shift pattern of the eccentric cam for reciprocating the plurality of plungers at a predetermined speed condition by the motor. And a pattern storage means for variably storing the shift pattern created by the shift pattern creating means, and the pressure detection when the eccentric cam rotates at a constant speed under a predetermined discharge load condition. Means for correcting the shift pattern stored in the pattern storage means so that the plunger moves at the predetermined speed condition, based on the detection information of at least one of the means and the displacement amount detection means, according to the rotation angle of the eccentric cam. When the eccentric cam rotates under the predetermined discharge load condition with the shift pattern corrected by the first correcting means, the detected value of the pressure detecting means becomes substantially constant. The speed change pattern stored in the pattern storage means is applied at the portion corresponding to the suction / discharge switching of the plunger reciprocating pump. Second correction means for correcting, a motor drive signal corresponding to the shift pattern stored in the storage means is generated, and the motor is driven by the motor drive signal to drive the plurality of eccentric cams in the pattern storage means. A drive control device for a plunger reciprocating pump, comprising: a motor drive circuit that rotates a stored gear shift pattern. 2. The driving of the plunger reciprocating pump according to claim 1, wherein the movement of the plunger under a predetermined speed condition is a substantially constant speed movement of the plunger at a reference speed. Control device.