JPH0648499A - Controlling method for dispenser - Google Patents

Abstract

PURPOSE:To precisely discharge a certain slight amount of a fluid in the full stroke of a piston by giving a correction conformable to the remaining quantity of the fluid to a command signal at a set value corresponding to the material, viscocity and the like of the fluid from the side of a controlling means for commanding the feed quantity of the piston to a piston stroking means even when a residual stress with respect to the fluid varies due to variations in the remaining quantity of the fluid in a cylinder. CONSTITUTION:In reciprocating drive means 8, 10, the feed quantity of a piston 3 in every discharge operation is set by a command signal from a controlling means 100. Further, in the controlling means 100, a correction value conformable to stress strain to be caused to the piston 3 and/or a cylinder 2 in response to the material, viscocity and the like of a fluid is set according to variations in the remaining quantity of the fluid in the cylinder 2, whereby the command signal is corrected so as to regulate the feed quantity of the piston.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control system for a dispenser which separates and cuts a predetermined amount of a fluid from a container containing a fluid such as an adhesive.

[0002]

2. Description of the Related Art A dispenser of this type is usually provided with an opening / closing valve at the discharge port of a container, and a required atmospheric pressure is applied to the container side. Depending on the opening time of the opening / closing valve, a fluid such as an adhesive is discharged in a required amount, or a pump mechanism is provided between the container and the discharge port, and the pump mechanism operates. The required amount of fluid is being discharged.

However, in the above-mentioned conventional example, in the case where the fluid is hardened with time with the above-mentioned adhesive or the like, the opening / closing valve or the pump mechanism must be thoroughly cleaned before hardening. And maintenance is very difficult. Also, with the above-mentioned configuration, it is difficult to cut out a very small amount of fluid, and it cannot be used for a fluid cutting operation such as precision dispensing.

[0004]

Therefore, it has already been possible to discharge the fluid from the container without any mechanical structure, maintenance is easy, and a disposable container or the like can be adopted. A dispenser has been proposed, which can cut out a very small amount intermittently or continuously. This dispenser adopts a so-called syringe-type container, which is composed of a cylinder having a discharge opening at one end and a piston slidably fitted in the cylinder, as a container for storing a fluid, The dispenser main body side on which the container is detachably mounted is equipped with a driving means for performing a predetermined feeding operation with respect to the piston.

However, the problem here is that when the container is made of a material such as synthetic resin which is distorted and expanded at a relatively low pressure, and the fluid contained in the container is For example, in the case of containing a gas such as air and having a compressibility, even if the feed amount of the piston for each cutting operation is set to be constant by the driving means,
As the residual amount of the fluid in the cylinder changes, the residual stress on the fluid may change, and it may not be possible to cut out a certain amount of precise minute amount.

[0006]

SUMMARY OF THE INVENTION The present invention has been made based on the above circumstances. Even when the residual amount of the fluid in the cylinder changes and the residual stress on the fluid changes, the piston feed amount is transmitted to the piston driving means. On the control means side that issues a command, the command signal is corrected with a set value corresponding to the material and viscosity of the fluid, and a fixed amount of precise micro-cutting is realized in the entire stroke of the piston. It is intended to provide a dispenser control method that is made possible.

[0007]

Therefore, in the present invention,
From a container composed of a cylinder having an ejection opening at one end and a piston slidably fitted in the cylinder, a fluid contained therein is driven by the reciprocating drive means to drive the piston. In a dispenser control system in which a predetermined amount is separately cut out, in the reciprocating drive means, the feed amount of the piston for each cutting operation is set by a command signal of the control means, and in the control means, the flow A correction value commensurate with the stress strain generated in the piston and / or the cylinder corresponding to the material of the body, the viscosity, etc. is set according to the change of the remaining amount of the fluid in the cylinder, and the feed amount is adjusted, The command signal is corrected.

[0008]

As a result, even if the residual amount of the fluid in the cylinder changes and the residual stress on the fluid changes in the course of the piston feeding operation by the driving means, a certain amount of precise micro-cutting is performed. Can be realized.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to the drawings. Here, since the fluid stored in the container 1 is separated and cut out by a predetermined amount, the container 1 is
It is of a syringe type, which is composed of a cylinder 2 having an ejection opening 2A at one end and a piston 3 slidably fitted in the cylinder 2. This container 1 is a device frame 4
In this case, the cylinder 2 is attached to the device frame 4 in the operating direction of the piston 3,
That is, the cylinder holder 5 is provided so that it can be detachably mounted in the vertical direction. In particular, in this embodiment, the cylinder holder 5 is composed of a stator 16 provided on the apparatus frame 4 and an annular screw member 17 screwed to the stator 16, and supports the cylinder 2 with a support flange. Hold 2B by sandwiching it from above and below
It is designed to be fixed.

Further, the apparatus frame 4 is equipped with a stepping motor 10 and a screw shaft 7 as a reciprocating drive means for reciprocating the piston 3. That is, the screw shaft 7 is axially supported with respect to the device frame in the operation direction of the piston 3 (vertical direction in this embodiment), and the drive element 8 is screwed thereto. . The drive element 8 includes a screwing piece 8A that is rotatably screwed into the screw shaft 7, and a pair of connecting rods 8B provided below the screwing piece 8A so as to be parallel to the screw shaft 7. And a piston connecting piece 8C located below the screw shaft 7 and attached to the lower end of the connecting rod 8B. The connecting rod 8B is provided on the device frame via a sleeve 9. It is slidably fitted to the support bracket 4A.

In this embodiment, the piston connecting piece 8C has a ball clutch structure. That is, as is known in the structure and operation of a general ball clutch, the piston connecting piece 8C has a stator 13 having an annular surface 13A which is tapered downward, and an insert for inserting the piston head 3A in the center. The clutch release operation is configured by an operator 15 having a hole 15A and having a large number of support holes 15B into which the balls 14 are inserted on the peripheral surface, and by pushing up an operation flange 15C provided on the operator 15. In addition, when it is lowered by its own weight, the clutch is engaged (that is, when the operating flange 15C is pushed up, the ball 14 faces the annular surface 13A side in the support hole 15B). The ball 14 moves away from the outer circumference of the piston head 3A inserted into the insertion hole 15A, but when the ball 14 descends by its own weight, the ball 14 moves toward the annular surface 13A. Pushed, pressed against the outer periphery of the piston head).

The stepping motor 10 is mounted on the upper part of the device frame 4, and its output shaft 1
0A extends downward and is connected to the screw shaft 7 via a coupling 11. The stepping motor 10 is controlled by the control means 100 such as a CPU,
Intermittent (or continuous) according to the required program
The screw shaft 7 can be rotated a required amount for each cutting of the fluid based on the command signal from the control means 100.

The initial stroke of the piston 3 is given to the control means 100 as data from the capacity of the container 1, the inner diameter of the cylinder, the filling amount of the fluid, and the material and viscosity of the fluid. A coefficient A corresponding to the above is set, and the correction value commensurate with the stress strain generated in the piston and / or the cylinder changes according to the change in the remaining amount (x) of the fluid in the cylinder y = A · f It is set as (x). Then, the reciprocating driving means, that is, the stepping motor 10 is corrected by correcting the command signal that determines the piston feed amount for each cutout corresponding to the given minute cutout amount with the correction value.
To give to.

The coefficient of f (x) is set according to the type of container used in this dispenser, for example, the material of the cylinder. Further, in the figure, reference numeral 12
Is a bearing for pivotally supporting the screw shaft 7 on the device frame 4.

In such a structure, the container 1 is set on the apparatus frame 4 by detachably holding the cylinder 2 on the cylinder holder 5 and detachably holding the piston 3 on the piston connecting piece 8C. After that, the screw shaft 7 is rotated by the rotation operation of the stepping motor 10 corresponding to the feed amount set by the control means 100. Therefore, the drive element 8 performs the feeding operation of the piston 3, and the fluid such as the adhesive can be cut out from the container 1 through the opening 2A for discharging in a predetermined amount.

In this case, unlike the conventional case, the mechanical portion does not exist in the passage of the fluid, so that in order to avoid obstacles such as solidification of the fluid in the passage, cleaning or the like is appropriately performed. There is no need to perform maintenance. Further, in some cases, there is an advantage that the container can be disposable.

In particular, in the present invention, even if the residual amount of the fluid in the cylinder 2 changes and the residual stress on the fluid changes, the control means for instructing the piston drive means the piston feed amount, As described above, since the command signal is corrected by the set value corresponding to the material and viscosity of the fluid, the command signal is corrected accordingly.
A certain amount of precise micro cutout can be realized.

The details will be described below. The operation of the stepping motor 10 is intermittent, and a command signal from the control means 100 causes the piston 3 to be pushed at a constant speed until the required minute amount of cutting is completed after the start of the feeding operation and the flow in the cylinder 2. Open the body 2A
Discharge from. During this time, the internal pressure of the cylinder 2 rises, but when the internal pressure at that time causes the cylinder 2 to expand and / or the fluid has compressibility, compression occurs, and the cut-out amount decreases correspondingly. Moreover, the value of the internal pressure (residual stress) for such a fluid becomes higher as the remaining amount of the fluid in the cylinder 2 becomes smaller. At the end, a considerable cutting amount error occurs. However, in the present invention, since the control means 100 corrects the command signal as described above, the amount of fluid cut out for each discharge is constant.

After cutting out the fluid, the fluid is extruded with time from the opening 2A due to the above-mentioned residual stress,
In some cases, problems such as drooping remain. Therefore, in the control system of the present invention, the control means sets the return amount of the piston corresponding to the material of the fluid, the viscosity, and the like, and outputs a command signal based on the return amount each time the discharge operation ends. You may make it give to a reciprocating drive means. As a result, the fluid that tends to flow out of the opening 2A due to the residual stress can be pulled back to the inside of the cylinder 2 and can be prevented from dropping.

In the above embodiment, the driving amount is set digitally by using the stepping motor 10 to drive the driving element 8. However, in a commonly used servo motor, etc., The drive amount may be set digitally or analogly. Further, although the driving element is fed by using the structure of the screw shaft 7, for example, a linear motor or the like is used as the motor, and the movable portion of the motor is directly attached to the driving element. Such a structure may be adopted.

Further, in the above-described embodiment, the control means is previously given the operation stroke of the piston as an initial value, and the stroke of each cutout of the fluid is reduced, that is, the remaining amount of the fluid in the cylinder is set. Correspondingly, although the correction value is set, the container 1 is initially empty, and the fluid is sucked into the cylinder 2 by the lifting operation of the piston 3 so that the fluid is filled in the container 1. In this case, the maximum stroke due to the suction at that time may be stored in the memory as an initial value, and the piston position for each cutout of the fluid may be calculated using this as a reference.

[0022]

The present invention has been described in detail above, and in the reciprocating drive means for pushing out the contents of the container, that is, the fluid by the piston, the above-mentioned operation for each cutting operation is performed by the command signal of the control means. The feed amount of the piston is set, and in the control means, a correction value commensurate with the stress strain generated in the piston and / or the cylinder corresponding to the material, viscosity, etc. of the fluid is set to the fluid in the cylinder. It is set according to the change in the remaining amount, and the command signal is corrected so as to adjust the feed amount, so cutting of the fluid from the container can be realized without any mechanical configuration, and maintenance is easy. So, disposable containers can be adopted,
Moreover, even if the residual amount of the fluid in the cylinder changes and the residual stress on the fluid changes in the course of the piston feeding operation by the driving means, a certain amount of precise microscopic cutting can be realized. Excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a side view of the above embodiment.

FIG. 3 is a front view showing a part of the above embodiment in a longitudinal section.

FIG. 4 is a side view showing another part of the above embodiment in a longitudinal section.

[Explanation of symbols]

 1 Container 2 Cylinder 3 Piston 4 Device Frame 5 Cylinder Holder 7 Screw Shaft 8 Drive Element 9 Sleeve 10 Stepping Motor 100 Control Means

Claims (2)

[Claims] 1. A container comprising a cylinder having a discharge opening at one end and a piston slidably fitted in the cylinder, and a fluid contained in the container. In the control method of the dispenser, which is configured to separate and cut out by a predetermined amount by driving, in the reciprocating driving means, the feed amount of the piston for each cutting operation is set by the command signal of the control means, and the control is performed. In the means, a correction value corresponding to the stress strain generated in the piston and / or the cylinder corresponding to the material and viscosity of the fluid is set according to the change in the remaining amount of the fluid in the cylinder, and the feed amount is set. A control system for a dispenser, wherein the command signal is corrected so as to be adjusted. 2. The control means sets the amount of return of the piston corresponding to the material and viscosity of the fluid, and outputs a command signal based on this to the reciprocating drive means each time each cutting operation is completed. The dispenser control system according to claim 1, wherein the dispenser control system is provided.