JP3634959B2 - Nozzle device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nozzle device, and more particularly to a nozzle device in which a nozzle tip is detachably attached to a nozzle base.
[0002]
[Prior art]
In a nozzle device such as an automatic dispensing device, a nozzle tip made of a transparent resin or the like is attached to a metal pipe-like nozzle base. The liquid sample is sucked and discharged by the nozzle tip. The nozzle base is supported by a transport mechanism that transports it three-dimensionally. When a chip is mounted, first, the nozzle base is positioned above any nozzle chip held in the chip rack, and the nozzle base is lowered to insert the taper portion of the nozzle base into the upper end opening of the nozzle chip. , Both join. The mounting force at that time is adjusted by controlling the lowering amount of the nozzle base. Note that the conventional nozzle device transport mechanism includes a jamming sensor for detecting, for example, a state in which the tip of the nozzle tip has accidentally collided with the edge of the discharge destination container. The sensor directly detects the mounting force. Not like that.
[0003]
[Problems to be solved by the invention]
By the way, in the conventional device, when there is an error in the taper angle inside the upper opening of the nozzle tip, or when the taper surface of the nozzle base is worn, there is a problem that the nozzle tip cannot be mounted with an appropriate mounting force. . In that case, various problems such as chip dropping, air leak at the time of suction and discharge, chip mounting with excessive mounting force, and the like occur.
[0004]
Also, if there is an error in the lowering amount of the nozzle base, the mounting force will fluctuate accordingly, the nozzle base will enter the nozzle tip more than necessary or the insertion will become shallower, and the dead volume of the piping will not be constant. The problem arises. That is, there is a concern that the dispensing accuracy will be affected.
[0005]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a nozzle device capable of appropriately controlling the mounting force when a chip is mounted.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a nozzle device that sucks and discharges liquid by a nozzle composed of a nozzle base and a nozzle chip that is detachably attached to the nozzle base. At least one mounting force sensor that is provided on a mounting surface to be mounted and detects the mounting force of the nozzle chip, and a control unit that controls mounting of the nozzle chip based on a signal from the mounting force sensor. It is characterized by that.
[0007]
According to the above configuration, when the nozzle tip is mounted on the nozzle base, the mounting force is directly detected by the mounting force sensor, and the mounting operation is controlled according to the detected mounting force. For example, the mounting force is controlled to be a constant value by adjusting the lowering amount of the nozzle base. As a result, problems associated with variations in mounting force can be solved, and dispensing reliability and accuracy can be guaranteed.
[0008]
In a preferred aspect of the present invention, the mounting surface is provided with a deterioration detection sensor that detects the state when the mounting surface is worn. When the mounting surface is worn out due to long-term use of the nozzle, there is a risk of mounting failure and error in detecting the mounting force, but such problems can be prevented beforehand by monitoring the mounting surface for deterioration.
[0009]
In a preferred aspect of the present invention, the control unit controls an elevating mechanism that elevates and lowers the nozzle base, and controls the mounting force of the nozzle tip on the nozzle base to a constant value.
[0010]
In a preferred aspect of the present invention, the mounting surface is provided with a plurality of mounting force sensors separated from each other in the circumferential direction thereof, and the control unit controls the mounting based on the output of each mounting force sensor. I do. Preferably, the two mounting force sensors are provided on the mounting surface while being separated from each other by 90 degrees in the circumferential direction.
[0011]
For example, even when the mounting pressure (contact force) at each part varies due to deformation of the insertion hole of the nozzle tip or partial wear of the nozzle base, the state can be detected by a plurality of mounting force sensors. In this case, the mounting control may be performed using the average value of the mounting forces detected by the respective mounting force sensors, or a plurality of detected mounting forces are compared with each other and the smallest one is used. Mounting control may be performed. Considering that the detected mounting force is considered to be approximately equal on one side and the other side in the circumferential direction, and that it is considered sufficient to detect the mounting force for only one of them, the mounting force sensor It is most reasonable to provide two of them with 90 degrees different in the circumferential direction.
[0012]
In a preferred aspect of the present invention, there are included means for comparing the signals from the plurality of mounting force sensors to determine a detection abnormality and means for executing an error process when the detection abnormality is determined. When an abnormality occurs in any of the plurality of mounting force sensors, there is a possibility that proper mounting control cannot be performed, and this is determined by comparison between signals, and error processing is performed.
[0013]
In a preferred aspect of the present invention, means for monitoring a signal from the mounting force sensor during the dispensing operation to determine a decrease in the mounting force, and an error process when the decrease in the mounting force is determined. Means. According to this configuration, during the dispensing operation, it is possible to always monitor the mounting state, and it is possible to perform error processing by detecting a situation such as occurrence of a leak or loosening or dropping of the nozzle tip.
[0014]
In a preferred aspect of the present invention, the presence / absence of a nozzle tip is determined based on a signal from the mounting force sensor. According to this configuration, there is an advantage that it is possible to determine the absence of the nozzle tip during the nozzle tip mounting operation and the drop of the nozzle tip during the dispensing operation.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0016]
FIG. 1 shows a preferred embodiment of a nozzle device according to the present invention, and FIG. 1 is a conceptual diagram showing the overall configuration thereof. This nozzle device substantially functions as an automatic dispensing device.
[0017]
In FIG. 1, a nozzle 10 that sucks and discharges a liquid includes a nozzle base portion 12 made of metal or the like, and a nozzle tip 14 that is detachably attached to the nozzle base portion 12. Here, the nozzle tip 14 is, for example, a molded product such as a resin, and is exchanged every time the liquid is dispensed. That is, the nozzle tip 14 is a disposable tip.
[0018]
The nozzle chip 14 is aligned and held in the chip rack 16 before being mounted on the nozzle base 12. When the nozzle tip 14 is mounted, the nozzle base 12 is positioned above the specific nozzle tip 14, the nozzle base 12 is lowered from the position, and the tip of the nozzle base 12 is fitted into the upper opening of the nozzle tip 14. By inserting, the nozzle tip 14 is attached to the nozzle base 12. After the mounting, the nozzle 10 is raised, and then a dispensing process is executed. After dispensing, the nozzle tip 14 is removed from the nozzle base 12 and discarded.
[0019]
As shown in FIG. 1, a mounting force sensor 18 and a deterioration sensor 19 are provided on the mounting surface 12 </ b> A at the tip of the nozzle base 12. The mounting surface 12A is formed as a tapered surface, and the mounting surface 12A is surface-bonded to the tapered surface 14A formed on the nozzle chip 14 side. That is, the two surfaces are connected by joining the surfaces, that is, by fitting the nozzle base 12 and the nozzle tip 14 together.
[0020]
The mounting force sensor 18 is a sensor that directly detects the mounting force when the nozzle chip 14 is mounted. The mounting force sensor 18 is composed of, for example, a strain gauge. Of course, various sensors can be used as long as the mounting force can be detected. At least one mounting force sensor 18 is provided, and preferably two are provided at regular intervals in the circumferential direction of the nozzle base 12 as will be described later.
[0021]
The degradation sensor 19 is a sensor that is provided on the mounting surface 12A as with the mounting force sensor 18 and detects wear on the mounting surface 12A by using a joint with the tapered surface 14A. The specific structure will be described later. The transport mechanism 24 is a mechanism that transports the nozzle 10, and the transport mechanism 24 includes a drive motor and the like.
[0022]
The dispensing pump 20 is connected to the nozzle base 12 by a tube 21 and is a means for generating suction force and discharge force. A driving signal is supplied to the dispensing pump 20 from the pump driving unit 22.
[0023]
The control unit 26 controls each means in the apparatus including the transport mechanism 24 and the pump drive unit 22. In this embodiment, the control unit 26 receives the mounting force detection signal 100 output from the mounting force sensor 18 and the deterioration sensor 19. An output deterioration detection signal 102 is input. That is, the control unit 26 performs various operation controls including the mounting control of the nozzle tip 14 according to the mounting force detection signal 100 and the deterioration detection signal 102.
[0024]
FIG. 2 shows the appearance of the mounting force sensor 18. In the present embodiment, a mounting force sensor 18 extending in the axial direction of the nozzle base is provided at the center of the mounting surface 12A. Thus, when the mounting force sensor 18 is exposed on the mounting surface 12A, the mounting force sensor 18 contacts the tapered surface 14A when the nozzle chip 14 is mounted. The pressing force or distortion generated at the time of contact is detected by the mounting force sensor 18, and the detection result is output as the mounting force detection signal 100 as described above. Incidentally, the signal line connected to the mounting force sensor 18 passes through the nozzle base 12 and is drawn out to the control unit 26 as described above. Note that the mounting force sensor 18 is not limited to that shown in FIG. 2, and for example, a circular sensor may be used, or an annular sensor formed along the circumferential direction may be used.
[0025]
FIG. 3 shows the structure of the deterioration sensor 19 shown in FIG. The deterioration sensor 19 includes a balloon 30 that slightly bulges from the mounting surface 12A, and electrodes 32 and 34 that are provided on the inner surface of the balloon 30 so as to face each other. When the mounting surface 12A is not worn, the two electrodes 32 and 34 are not in contact with each other even when the balloon 30 is pressed. On the other hand, when the mounting surface 12A is worn and worn, the mounting of the nozzle tip 14 is performed. Sometimes the balloon 30 is crushed, and as a result, the electrodes 32 and 34 come into contact with each other, and the deterioration detection signal 102 shown in FIG. 1 is output. For example, air is injected under pressure into the balloon 30 and itself has elasticity. Of course, as long as the wear of the mounting surface 12A can be detected, various deterioration sensors can be used. It is desirable to apply a coating or the like to protect the surface of the balloon 30.
[0026]
FIG. 4 shows an example of the AA ′ cross section shown in FIG. In the example shown in FIG. 4, two mounting force sensors 18 </ b> A and 18 </ b> B are provided along the circumferential direction of the nozzle base 12, specifically, at an angle of 90 degrees. Indeed, the above-described deterioration sensor 19 is also provided. Furthermore, in the example shown in FIG. 4, the coating 40 is applied over the entire mounting surface 12A. The coating 40 is composed of a thin layer such as silicone.
[0027]
According to the configuration example shown in FIG. 4, even when the mounting force is different at each part in the circumferential direction of the mounting surface 12 </ b> A, it can be reasonably detected. That is, since the mounting forces detected on one side and the other side in the circumferential direction are considered to be substantially equal, the two mounting force sensors 18A, 18A, If 18B is provided, more significant information can be acquired. Incidentally, in the configuration example shown in FIG. 4, the deterioration sensor 19 and the mounting force sensor 18B are provided on one side and the other side in the circumferential direction, but they may be provided so as not to line up in the diameter direction. The signal lines from the mounting force sensors 18A and 18B and the deterioration sensor 19 may be bundled with each other and passed through the nozzle base 12, or may be individually passed through the nozzle base 12.
[0028]
FIG. 5 shows each process of dispensing control in the control unit 26. In S101, the nozzle base 12 is positioned above the nozzle tip 14 to be attached to the nozzle base 12, and the nozzle base 12 is pulled downward from the positioned state. At the same time, monitoring by the mounting force sensor 18 and the deterioration sensor 19 is started.
[0029]
In S <b> 102, it is determined whether the mounting force has reached a certain value K based on the mounting force detection signal 100 from the mounting force sensor 18. In the case of the configuration example shown in FIG. 5, the determination in S102 is performed based on the mounting force detection signals from the two mounting force sensors 18A and 18B, and whether or not the average value has reached a certain value K. Has been determined. Of course, the determination in S102 may be performed based on the smaller of the detected two mounting forces.
[0030]
In this embodiment, if the level difference between the two mounting force detection signals is greater than or equal to a certain value in S102, it is determined that the signal is abnormal, and error processing is executed in S103. Alternatively, the signal abnormality is determined even when the level of any of the mounting force detection signals is out of the appropriate range.
[0031]
If it is determined in S102 that the mounting force has reached a certain value K, the descent of the nozzle base 12 is stopped in S104. In S <b> 105, it is determined whether wear has occurred on the mounting surface 12 </ b> A of the nozzle base 12 based on the deterioration detection signal 102. If it is determined that wear has occurred, error processing is executed in S103.
[0032]
In S106, the whole nozzle 10 is pulled upward, and then a dispensing process is executed as in the conventional case. During the execution of the dispensing process, the control unit 26 constantly monitors the mounting force detection signal 100. If the level falls below a predetermined value, it is determined that the mounting force has decreased, and error processing is performed in S103. Execute. That is, for example, loosening or leakage of the nozzle tip 14 due to vibration during the conveyance of the nozzle 10 is detected by a decrease in mounting force, thereby ensuring an appropriate dispensing operation.
[0033]
In S107, after dispensing is completed, monitoring of the mounting force detection signal by the control unit 26 is completed, and the nozzle tip 14 is removed from the nozzle base 12 and discarded. In S108, it is determined whether or not to repeat the above steps.
[0034]
Therefore, according to the above control, the mounting force of the nozzle tip 14 can always be maintained at a constant value so that the nozzle tip 14 can be properly mounted on the nozzle base 12 and the mounting state can be maintained even after the mounting. There is an advantage that it can be monitored. Furthermore, since the presence or absence of wear of the mounting surface 12A is also detected, there is an advantage that the above determination can be performed more accurately.
[0035]
【The invention's effect】
As described above, according to the present invention, the mounting force at the time of chip mounting can be appropriately controlled.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a preferred embodiment of a nozzle device according to the present invention.
FIG. 2 is an external view of a mounting force sensor.
FIG. 3 is a diagram showing a structure of a deterioration sensor.
FIG. 4 is a view showing a cross section of a tip portion of a nozzle base portion.
FIG. 5 is a diagram showing the contents of control by a control unit.
[Explanation of symbols]
10 nozzles, 12 nozzle bases, 14 nozzle tips, 16 tip racks, 18 mounting force sensors, 19 deterioration sensors, 20 dispensing pumps, 22 pump drive units, 24 transport mechanisms, 26 control units.

Claims (8)

In a nozzle device that performs suction and discharge of a liquid by a nozzle composed of a nozzle base and a nozzle chip that is detachably attached thereto,
At least one mounting force sensor that is provided on a mounting surface on which the nozzle tip is mounted on the nozzle base and detects the mounting force of the nozzle chip;
A control unit for controlling the mounting of the nozzle chip based on a signal from the mounting force sensor;
A nozzle device characterized by comprising: The apparatus of claim 1.
The nozzle device according to claim 1, wherein the mounting surface is provided with a deterioration detection sensor that detects the state when the mounting surface is worn. The apparatus of claim 1.
The said control part controls the raising / lowering mechanism which raises / lowers the said nozzle base, and controls the mounting force of the said nozzle chip to the said nozzle base to a fixed value, The nozzle apparatus characterized by the above-mentioned. The apparatus of claim 1.
A plurality of the mounting force sensors are provided on the mounting surface while being separated from each other in the circumferential direction,
The nozzle device according to claim 1, wherein the control unit performs mounting control based on an output of each mounting force sensor. The apparatus of claim 4.
2. The nozzle device according to claim 1, wherein two mounting force sensors are provided on the mounting surface while being separated from each other by 90 degrees in the circumferential direction. The apparatus of claim 4.
Means for comparing the signals from the plurality of mounting force sensors to determine a detection abnormality;
Means for executing error processing when the detection abnormality is determined;
A nozzle device comprising: The apparatus of claim 1.
Means for monitoring a signal from the mounting force sensor during a dispensing operation to determine a decrease in the mounting force;
Means for executing an error process when it is determined that the mounting force is reduced;
A nozzle device comprising: The apparatus of claim 1.
A nozzle device comprising means for determining the presence or absence of the nozzle tip based on a signal from the mounting force sensor.

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