JPH0772533B2 - Automatic liquid feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention eliminates the pulsation that occurs when switching between suction and discharge of a reciprocating pump composed of two syringes, and automatically delivers a constant discharge amount. Regarding a liquid feeding device.

"Prior Art" A device for continuously sending a liquid is, for example, Shoukai 57-88.
There is No. 075, which operates the reciprocating pumps alternately by symmetrically alternately reciprocating a rack connected to each piston of a double piston type reciprocating pump by one gear. The liquid is continuously sent while being performed.

[Problems to be Solved by the Invention] However, in the conventional reciprocating pump, the pistons of the two reciprocating pumps are alternately reciprocated by the racks connected so as to interlock with each other by gears. When the direction is switched, the rotation of the gear is temporarily stopped and then reversed. However, the operation could not be corrected because it was operated by one drive motor. Therefore, when the end point and the start point of the moving distance of the piston are switched, pulsation occurs in the discharge amount, and there is a problem that a constant amount of discharge cannot be continuously performed. In addition, this type of pump prevents the occurrence of pulsation when the piston is turned back by correcting the operation of the motor with a cam or the like while alternately reciprocating two pistons with one motor. It was almost impossible to eliminate pulsation with a single motor.

"Means for Solving the Problem" The present invention relates to a pair of syringes that move forward and backward alternately and a first and a second syringe.
The three-way valve and the first suction port of the first three-way valve are connected with the first suction tube of the first three-way valve, respectively, by connecting the three-way valve with the first and second tubes. The first branch part provided on the way is connected to the second suction port of the second three-way valve by the second suction tube, and is provided on the way of the first discharge tube connected to the first discharge port of the first three-way valve. To the first and second pulse motors that connect the two-branch part and the tip of the second discharge tube that connects to the second discharge port of the second three-way valve, and connect to the pulse control circuit via the first and second motor drive circuits. The first and second pistons, which are housed in the syringes so as to be movable back and forth, through the first and second piston rods connected to the first and second pistons, are interlocked with the interlocked first and second ball screw mechanisms, A microcomputer that controls the 1 and 2 pulse motors and the entire automatic liquid feeder A control box having a digital display unit for displaying the input numerical value, as well as inputting a numerical value by operating a frequency oscillator that oscillates a frequency serving as a reference of a flow rate and a key operation on a keyboard display, which is connected via the pulse control circuit. A control circuit, an input / output control device, and a speed control circuit, which are connected to each other, are connected to the microcomputer, and the discharge amount for alternately sending liquid from two syringes and the discharge amount of one syringe before the decrease of the discharge amount of the other It is characterized in that the discharge from the syringes is started and the combined discharge amount obtained by combining the discharge amounts from both syringes is adjusted to be the set discharge amount.

"Action" The same discharge amount is sent from two syringes,
The discharge from one syringe is started before the decrease in the discharge volume of one syringe is started by subtracting or adding the rising and falling pulses at the time of starting and ending the piston that moves back and forth in the syringe, respectively. By complementing each other, the combined discharge amount that is the same as the set discharge amount is discharged to prevent the occurrence of pulsation during syringe switching, and to maintain a constant discharge amount. You can In this way, it is possible to continuously supply the set discharge amount so that the discharge amount from one syringe or the other syringe and the combined discharge amount that complements the discharge amount from both syringes become constant. It can be so.

[Embodiment] An embodiment of the present invention will be described with reference to FIG. 1. A pair of piston type syringes A and B and first and second three-way valves 5 and 10 are shown.
And the first suction tube 6 of the first three-way valve 5 are connected to each other by the first suction tube 21. A first branch portion 24 is provided in the middle of the tube. The tip of the first discharge tube 22 connected to the first discharge port 7 of the first three-way valve 5 has a second discharge tube connected to the second discharge port 12 of the second three-way valve 10.
It is connected to a second branch portion 25 provided in the middle of 22a, and the tip of the second discharge tube is arranged at a predetermined position where liquid supply is required. The tip of the second suction tube 21a connected to the second suction port 11 of the second three-way valve 10 is connected to the first branch portion 24 provided in the middle of the first suction tube 21.

Reference numerals 31 and 32 are first and second pulse motors for advancing and retracting the first and second pistons 3 and 4, which are mounted in the syringes A and B so as to be able to move back and forth, respectively. First and second piston rods 3a and 4a connected to the first and second pistons 3 and 4 are connected to be alternately moved back and forth. The forward and backward movements of the first and second pistons 3 and 4 are the first and second movements.
The first and second pulse motors are controlled through the motor drive circuits 41 and 42, and a 10 MHz click by the frequency oscillator 48 serving as a reference for adjusting the discharge amount is divided by the control by the microcomputer 45. . In this case, the first, second and third limit switches 36, 37, and 37 are respectively provided at the middle and both ends of the moving distance of the protrusion 35 provided at the rear end of the one rod 3a.
38 are installed respectively. That is, when the first pulse motor 31 advances the first piston rod 3a via the ball screw mechanism 33, the protrusion 35 provided at the rear end of the rod 3a advances and the first limit switch 36 located at the intermediate portion. Engage with.
Then, the second piston rod 4a on the other side retreats at a speed twice as fast as the forward speed and quickly sucks the liquid into the syringe B to prepare for the next discharge. When the first piston 3a moves forward and approaches the front end of the syringe A, the second limit switch
Simultaneously with or immediately before the decrease of the discharge amount starts by engaging with 37, the discharge from another syringe B is started, and the combined discharge amount obtained by combining the discharges from both syringes A and B is the same as the set discharge amount. Since it is set so that a constant discharge amount can be continuously supplied. The piston 3 stops its advance after engaging the second limit switch 37,
At that time, the discharge amount from the syringe B is the set discharge amount.

40 is a pulse control circuit, which is the first and second motor drive circuits 41, 42.
It is connected to the first and second pulse motors 31 and 32 via.
A speed control circuit 43 divides a 10-megahertz click for controlling the suction amount or the discharge amount of the liquid by the control of the microcomputer 45. The microcomputer 45 controls the entire automatic liquid feeder and is connected to a control box 47 having a keyboard via a control circuit 46. Reference numeral 48 is a frequency oscillator composed of a crystal oscillator or the like, which serves as a reference for adjusting the discharge amount and is connected to the microcomputer 45. 49 is a RAM, that is, a random access memory, 50 is an erasable programmable ROM (read only memory), 51 is an input / output control device, 54 is a communication circuit connected to the communication line 52, and an external host computer
Connected to 55. Reference numeral 56 is a plug for connecting to an external power source, 57 is a noise suppressor, 58 is a power supply circuit for driving the switch of the control box, 58a is a constant current circuit for operation, and the first and second motor drive circuits 41, 42 are provided. Connected to.

FIG. 2 shows a state in which the automatic liquid feeder comprising the syringes A and B continuously discharges the liquid as shown in I to VIII, and “%” indicates the set liquid. It means the discharge amount, and “stop” means that the piston in the syringe is stopped. "100% discharge" means the set discharge amount of liquid by moving (advancing) the piston. Further, "100-200% suction" means that the piston in the syringe is moved at a speed (maximum 2 times) higher than the speed (100%) corresponding to the set discharge amount to rapidly suck the liquid. Both syringes A and B are "0-100% spitting"
In the case of, it means that the combined discharge amount of the syringes A and B is the same as the set discharge amount.

Referring to FIG. 2 “I”, the advance of the piston of the syringe B is stopped and the discharge of the liquid is finished, and the piston 3 of the syringe A is started and set before the piston of the syringe B is stopped. It shows a state in which the liquid is being ejected at the ejection amount.

Referring to FIG. 2 "II", the piston of the syringe A continuously advances from "I" to continuously deliver the set discharge amount, while the piston 4 of the syringe B prepares for the next discharge. The piston 4 is retracted at a speed (maximum 2 times) higher than the forward speed of the piston 4 moving forward in the syringe B to suck the liquid, and a suction amount larger than the discharge amount of the syringe A is sucked in a short time. Prepare for the next ejection of Syringe B.

Referring to FIG. 2 “III”, the piston B of the syringe B stops retreating to complete the suction of the liquid and prepare for the next discharge. Further, the syringe A continues to eject the liquid at the set ejection amount by moving the piston forward.

Referring to FIG. 2 "IV", the piston of the syringe A approaches the stop position and the discharge amount decreases, while the syringe B starts to discharge gradually while advancing the piston 4 immediately before that. The combined ejection amount including the ejection amounts of B is set to be the same as the set ejection amount.

Referring to FIG. 2 "V", when the syringe A finishes discharging, the piston 3 stops, but the syringe B advances the piston 4 to deliver the set discharge amount.

Referring to FIG. 2 "VI", when the discharge amount of the syringe B approaches the end and the discharge amount starts to decrease, the other syringe A moves faster than the forward speed of the piston 3 that delivers the discharge set amount (maximum 2 Piston 4 of other syringe A
Retreat starts and the liquid is rapidly sucked in to prepare for the next discharge.

Referring to FIG. 2 "VII", the suction of the syringe A is completed and the retreat of the piston 3 is stopped. On the other hand, the piston 4 of the syringe B moves forward and continues to discharge at the set discharge amount.

Referring to FIG. 2 "VIII", as the piston 4 of the syringe B approaches the stop and the end of the discharge approaches, the discharge amount starts to decrease, and the piston 3 of the syringe A advances to start the discharge. The combined ejection amount of B and B is set to be the same as the set ejection amount. In this manner, the syringes A and B are alternately reciprocated to continuously discharge a fixed amount of liquid.

The operation panel of the control box 47 shown in FIG. 4 will be described. The numeric keypad 59, the entry key 60, and the subtraction key 61, which are numbers 0 to 9, form a numeric keypad portion D. Entry key 60 is the amount of "+" to be corrected, and subtraction key
For 61, enter the amount of "-" to be corrected in%. Mode part E
Has first and second keys 62 and 63 for issuing commands to move the syringes A and B upward or forward and to move them downward or backward. In this case, when the syringe is installed vertically, it moves up and down, but when the syringe is installed horizontally, it moves forward and backward. The fifth key 66 is syringe A,
The discharge amount of B is set in ml, and the sixth key 67 is for setting the discharge speed in ml / min. The seventh key 68 sets a discharge time with respect to the setting of the discharge amount of the fifth key 66.

The eighth key 69 is for instructing the suction operation of the syringes A and B, and the ninth key 70 is for instructing the discharge operation of the syringes A and B. The tenth key 71 is for stopping the syringe at the front and rear ends in the suction / discharge operation, and the eleventh key 72 is for continuously sucking or discharging the liquid from the syringes A and B. The twelfth key 73 is a mode key for ejecting the syringes A and B at the amount and speed or time set in the basic pattern. The thirteenth key 74 includes syringes A and B for a first up key 64a, a first down key 64b, a second up key 65a, and a second key.
The down key 65b is used to feed the quill step. The 14th key 75 is a program setting key that can set up to 99 steps when operating the 10th key 71 and the 11th key 72, and the 15th key 76 is how many times the predetermined programming is repeated when setting the program. Is for setting. The sixteenth key 77 is for correcting the discharge amount at the time of setting, and is a key for inputting the amount of “+” or “−” of the desired correction by using the numeric keypad in%. 78 is a start key for starting the operation of the pump (not shown),
79 is a stop key for inserting a stop time (pause time) between discharges when stopping the pump or setting a program, and the stop time can be set by continuously inputting the time.

The principle of the constant flow rate according to the present invention will be described with reference to FIGS. 3A and 3B. The A axis and the B axis respectively indicate the discharge amounts of the syringes A and B, and the set speed a of the syringe A and the set speed of the syringe B b is set to be equal by adjusting the frequencies of the pulse motors 31 and 32 with the microcomputer 45. Further, "to" represents the set discharge amount of the syringe A, "ri" represents the set discharge amount of the syringe B, and "chi" indicates that the piston in the syringe A or B retracts at a maximum speed of 2 times. It means the liquid that has been aspirated. That is, since the suction is performed at a speed twice as fast as the forward speed at maximum, the backward speed of the piston is about half the forward speed, and the piston can be prepared for the next discharge.

Set speed a = b Discharge amount To = Re = Ro + C Syringe A and B discharge amount rising and falling pulse numbers, that is, the rising pulse number c of the flow rate of the syringe A and the falling pulse number d, and The rising pulse number e and the falling pulse number f of the discharge amount of the syringe B can be set equal by subtracting or adding to the same rate in the internal calculation of the microcomputer 45.

The number of rising and falling pulses c = d = e = f The four triangles “a”, “b”, “c”, and “d” shown in FIG. Has the same right triangle, and the discharge amount is set by complementing each other on the A-axis “B” and the B-axis “C”. The suction speed of the syringe is set to a speed twice as high as the discharge speed at the maximum so that the suction of the liquid is quickly completed to prepare for the next discharge.

The first limit switch in which the piston 3 in the syringe A advances and the protrusion 35 provided at the rear end of the piston is installed in the middle.
When it engages with 36, and further moves forward to approach the stop position, the decrease of the discharge amount of the syringe A, which is the A axis, is started,
Under the same conditions, the discharge “C” of the syringe B, which is meant by the B axis, starts, and the combined discharge amount of both is the same as the set discharge amount. However, in reality, there are interruptions in the flow due to elements such as the reversal of the pump and the switching valve, so as shown in FIG. Start before the start of
It is necessary to superimpose the combined ejection amounts of both axes so that the set ejection amount is achieved.

The following formula is a formula derived by the inventor after repeating many experiments. That is, in FIGS. 3A and 3B, when the time (pulse number) before the decrease of the discharge amount of the A-axis is K, K = (V + 32) × 3 V = speed (pulse / min) Eliminate air bubbles, constant K shown in
Is set to prevent the pulsating flow from being generated during the combined discharge amount, and the fixed discharge amount is continuously fed.

Next, the operation of this embodiment will be described. First, the plug
56 is connected to an external power source (not shown), and a constant current circuit 58a,
The pulse control circuit 40 and the control box 47 are electrically connected, and the ejection speed, the ejection amount, and the ejection time are input numerically by the key operation on the control box 47.

Here, the discharge of the syringe A will be described with reference to FIG.
When the liquid discharge speed, discharge amount, and discharge time are set, the first
The driving force of the pulse motor 31 is transmitted to the first ball screw mechanism 33 to change the rotary motion into the linear motion, and the first piston rod 3A
The first piston 3 is moved forward via. This syringe A
The liquid inside is sent from the opened first discharge port 7 of the first three-way valve 5 through the first discharge tube 22 and the second branch portion 25 to the predetermined position from the tip of the second discharge tube 22a. In this case, since the first suction port 6 of the first three-way valve 5a is closed, the liquid in the container 16 is not sucked by the first three-way valve 5.

In addition, the suction of the syringe B will be described with reference to FIG. 1. By operating the keys of the control box 47, the driving force of the second pulse motor 32 is transmitted to the second ball screw mechanism 34 to change the rotational movement into a linear movement. Second piston rod
When the second piston 4 is retracted via 4a, the second three-way valve
A liquid is sucked from the container 16 into the syringe B through the first suction tube 21, the first branch portion 24, and the second suction tube 21a through the opened second suction port 11 of 10. In this case, the second discharge port 12 of the second three-way valve 10 is closed, the first suction port 6 of the first three-way valve 5 is also closed, and the second piston 4 has a reverse speed faster than the forward speed. To retreat to suck and then stop to prepare for the next discharge. When the syringe A continues to advance and engages with the second limit switch 37, the discharge amount starts to decrease, and at the same time, the second piston 4 in the syringe B starts to advance, and at the same time, the second three-way valve 10 switches. The second discharge port 12 opens, and the liquid in the syringe B is discharged from the second discharge tube 22a via the second discharge tube 22a and the second branch portion 25, and the combined discharge amount of both is equal to the set discharge amount. It's the same. Then, the first piston 3 is stopped, the discharge from the syringe A is stopped, and only the discharge amount from the syringe B becomes. In this case, the second discharge port 11 of the second three-way valve 10 and the first discharge port 7 of the first three-way valve 5 are both closed,
The first suction port 6 opens.

Then, the first piston 3 in the syringe A begins to retract,
The liquid in the container 16 sucks the liquid into the syringe A from the first suction port 6 via the first suction tube 21, but the second branch connected to the first branch portion 24 provided in the middle of the first suction tube 21. Since the second suction port 11 of the three-way valve 10 is closed, the second three-way valve
10 does not suck.

Each operation will be described below.

The manual / single mode (manual operation) of this device will be described. The 13th key 74 is operated to operate the syringes A and B.
Quill step feed with the first vertical movement keys 64a and 64b, and operates the tenth key 71 of the operation panel of the control box 47 to discharge or deliver liquid from the first and second three-way valves 5 and 10. If it is determined that discharge is to be performed, the discharge ninth key 70 is operated to instruct the syringe A to discharge by quill feed, and the pump is operated for 1 ml.
In this case, the other syringe B operates the eighth key 69 for suction to instruct to suck the liquid by quill feeding. It is determined whether or not the liquid is stopped, and when it is stopped, the pump is stopped and the discharge is completed. To continue discharging, operate the ninth key 70 for discharging again to turn on the pump.
Operate for 1 ml.

Explaining the auto / program / single mode, the 12th key 73 is used to determine which of the syringes A and B is to be used, or both of them, and to input the set discharge amount, speed and time. After operating the first key 62 or the second key 63, and then operating the ninth key 70 or the eighth key 69 for instructing the discharge or suction operation of the syringes A and B, operating the fifth key 66. Then, input the numerical value of the discharge amount and operate the entry key 60. Further, if the liquid feeding speed is determined, and if it is a set speed, the 7th key 68 is operated, then a numerical value is input, the discharge amount and the time are set, and then the entry key 60
To operate. If the speeds do not match, the 6th key 67 is operated, a numerical value is input, and the entry key 60 is further operated. In this case, when the number of steps displayed on the digital display unit 26 is finished, predetermined programming is performed by operating the fifteenth key 76 to repeat the number of steps and then stop. If you want to provide a liquid feeding pause, operate the stop key 79, then enter a numeric value and
Is operated to stop the discharge after a predetermined time. Then, a new program is input and the liquid feeding is repeated again.

Explaining the single mode, the 11th key 72, the 5th key
The discharge amount is set by operating 66, a numerical value is input by a key operation, and the discharge speed is set in units of ml by operating the sixth key 67 respectively. In addition, if you enter the discharge time in seconds and operate the entry key 60 and then the start key 78, the pump will start operating and the discharge will start, and when the discharge amount reaches the specified amount, stop the pump and perform the discharge work. Is completed.

The continuous mode will be described. The 11th key 72 is operated to set the syringes A and B so as to continuously discharge, the 5th key 66 is operated, and the numeric key “0” is input and then the entry key 60 is operated. Enter. Then, the sixth key 67 is input to input a numerical value for setting the discharge speed, and then the entry key 60 is operated and the start key 78 is operated to operate the pump to start the discharge. When the predetermined amount is reached, the stop key 79 is operated to stop the pump and stop the discharge.

Pause time when program injection is performed
To explain the case where there is not, first, to enter the program, the syringes A and B are set to a mode in which the syringes A and B discharge at the amount and speed or time set in the basic pattern.
The entry key 60 is operated by inputting with the key 73, inputting with the eleventh key 72 so as to discharge continuously, and further inputting a numerical value to set the discharge amount. When the discharge speed is inappropriate, a numerical value instructing the discharge operation of the syringe is input by key operation and the entry key 60 is operated. Then enter the program to stop the pump, or set the program to stop the pump or insert a stop (pause) time between discharges when setting the program.
, And input the time by key operation. Determine how many times the specified program should be repeated after it is delivered according to the program, and if so, enter the numerical value by key operation, operate the entry key 60, and then start the pump operation with the start key 78. Discharging starts when this is done.

Explaining the case where there is a stop (pause) time for performing program injection, the 12th key 73 for inputting a program and causing the syringes A and B to discharge at the amount, speed and time set in the basic pattern is operated. Enter the mode. The keys are operated so as to continuously discharge with both syringes, the sixth key 67 is further operated, and subsequently, a numerical value is input to set the discharge amount, and then the entry key 60 is input. To set the discharge rate by distinguishing this discharge speed, input the 6th key 67, then the numerical value, and press the entry key.
Operate 60. In order to set the discharge time in seconds with respect to the setting of the discharge amount, the 7th key 68 is input, a numerical value is input, and then the entry key 60 is operated. Enter the stop key 79, enter the time to stop after a predetermined time in seconds, then operate the 15th key 76 to set how many times the predetermined programming at the time of programming is repeated, and enter the number. Input key 60 and then start key 78.

[Advantages of the Invention] In the present invention, the forward and backward movements of the two syringes are controlled by the pulse motors respectively, so that both syringes are moved forward and the suction amount is made larger than the discharge amount in a certain period of time to finish the suction work quickly. By adjusting the timing of both pistons and preparing for the next discharge quickly, the liquid can be sucked and adjusted. In addition, when switching the liquid transfer, there is an interruption in the flow rate due to the reversal of the pump, the operation delay of the switching valve, etc.Therefore, before starting the decrease of the discharge amount of the syringe, gradually start discharging from the other syringe Since the combined discharge amount that is adjusted to the set discharge amount is adjusted to the set discharge amount, pulsation does not occur in the discharge amount, and liquid is delivered continuously for a long time while keeping the discharge amount per unit time constant. It has an advantage that can be achieved.

[Brief description of drawings]

FIG. 1 is an overall block diagram, and FIG. 2 is syringes A and B.
Of the suction and discharge state, Figure 3A is an explanatory view of the state of preventing the pulsating flow when switching from one syringe to the other, Figure 3B is a state in which the discharge of one syringe is a little earlier FIG. 4 is a plan view showing the operation panel of the control box. A, B ... Syringe, 1 ... First tube, 2 ... Second
Tube, 3 ... first piston, 4 ... second piston,
5 ... First three-way valve, 6 ... First suction port, 7 ... First discharge port, 10 ... Second three-way valve, 11 ... Second suction port, 12 ... Second
Discharge port, 16 ... Container, 21 ... First suction tube, 21a ...
… Second suction tube, 22 …… First discharge tube, 22a…
… Second discharge tube, 24 …… First branch, 25 …… Second branch, 31 …… First pulse motor, 32 …… Second pulse motor, 33 …… First ball screw mechanism, 34 …… Second 2 Ball screw mechanism, 35 ... Projector, 36 ... First limit switch, 37 ...
… Second limit switch, 38 …… Third limit switch, 40 …… Pulse control circuit, 41,42 …… Motor drive circuit, 43 …… Speed control circuit, 45 …… Microcomputer, 46 …… Control circuit, 47… …Control box. 48: Frequency oscillator, 51: Input / output controller.

Claims (1)

[Claims] 1. A pair of syringes that move back and forth alternately and a first,
The two three-way valves are respectively connected by the first and second tubes, and the container for containing the liquid for liquid transfer and the first suction port of the first three-way valve are connected to the first
While connecting with the suction tube, the first branch portion provided in the middle of the first suction tube and the second suction port of the second three-way valve are connected with the second suction tube, and the first discharge port of the first three-way valve. The second branch portion provided in the middle of the first discharge tube connected to the first discharge tube and the tip of the second discharge tube connected to the second discharge port of the second three-way valve are connected, and the pulse control circuit drives the first and second motors. First and second pistons connected to first and second ball screw mechanisms interlocked with first and second pulse motors connected via a circuit
Via the pulse control circuit, the first and second pistons, which are housed in the respective syringes through piston rods so as to be movable back and forth, are interlocked with each other, and the first and second pulse motors and a microcomputer for controlling the entire automatic liquid feeding device are provided through the pulse control circuit. And a control circuit that connects a control box with a digital display that displays the entered numerical value, as well as inputting a numerical value by operating the frequency oscillator that oscillates the frequency that is the reference of the flow rate and the key operation on the keyboard display. An input / output control device and a speed control circuit are connected to the microcomputer, and the discharge amount for alternately sending liquid from two syringes and the discharge from one syringe are started before the discharge amount of one syringe starts to decrease. In this way, the combined discharge amount that combines the discharge amounts from both syringes was adjusted to the set discharge amount. Dooku solution apparatus.