JP3362563B2 - Viscous liquid minute discharge detection device and viscous liquid discharge amount management device using this detection device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting a small amount of viscous liquid and a device for managing the discharge amount of a viscous liquid using this detecting device.

[0002]

2. Description of the Related Art Liquid sealing agents are used in processes such as filling holes in works, filling plug members, and adhering.

An example of processing steps using this liquid sealing agent is shown in FIG. This step is a step of embedding seven welch plugs 52 in the holes 51 of the automobile engine casing 50, in which a sealing agent is applied to the inner surfaces of the holes 51 to press-fit the welch plugs 52.

FIG. 8 shows an example of a sealant applying device used for applying a sealant to such a hole portion. This device is a device for efficiently applying the sealant to the hole portion.
In this device, a sealing agent is stored in a sealing agent tank 21, and the inside of the tank 21 is pressurized by air from an air source 20 and is supplied to the sealing valve 22 through a tube 27. And the seal valve 2
2 is opened and closed by the air valve 23, and when the seal valve 22 is opened, the sealing agent is discharged from the nozzle 24 through the tube 28. At this time, the rotating body 31 inserted in the hole 51 is rotated by the air rotating tool 32, and the sealing agent discharged from the nozzle 24 is rotated by the rotating body 31.
Is applied to the inner wall of the hole 51.

The amount of sealant applied is controlled by the air valve 2
The timer 29 provided in FIG. 3 operates with the passage of time, and the timer 29 starts the passage of time at the same time when the seal valve 22 opens, and automatically closes the seal valve 22 after a lapse of a certain time. Also, the air rotation tool 32 is also
It is automatically stopped by the time of a timer 30 provided in an air valve 25 for driving the air rotating tool 32. The sealant tank 21 is provided with a level detector 26 for knowing the amount of the sealant contained therein, and supplies the sealant appropriately when the amount of the sealant falls below a certain amount.

In such a sealant coating device, the sealant itself has a high viscosity and is hardened by volatilization of the solvent.
The sealant may be hardened at the tip and the seal may be clogged.

[0007] When such a seal clogging occurs, not only the sealing agent is not ejected well, and the uniform sealing agent cannot be applied, but if it is bad, the opening and closing of the sealing valve will occur and the sealing agent will not come out at all. Or (the valve cannot be opened) or the discharge of the sealing agent cannot be stopped (the valve cannot be closed).

[0008] If the sealing agent does not come out, there is a problem that the sealing agent is not applied and the quality of the processed product is greatly deteriorated. On the contrary, if the sealing agent is left out, the cost of the sealing agent increases. It becomes a problem.

In order to solve such a problem, it is necessary to accurately detect whether the sealing agent comes out or stops by the opening / closing operation of the sealing valve.

[0010]

However, the amount of the sealing agent discharged from the tip of the nozzle is extremely small, and the amount is about 0.03 ml or less.

For this reason, conventionally, there is no device for detecting the discharge of a minute amount of a viscous liquid such as a sealant, and the present situation is to visually check, and it is desired to detect this automatically. ing.

[0012] Therefore, an object of the present invention is to provide a small amount discharge detecting device for a viscous liquid capable of detecting a very small discharge amount of a viscous and curable liquid such as a sealant, It is another object of the present invention to provide a viscous liquid ejection amount management device that manages the ejection amount of a viscous liquid by using this minute amount ejection detection device.

[0013]

The present invention for achieving the above object is achieved by releasing a part of a flow path through which a viscous liquid passes,
A micro-viscosity detection device for a viscous liquid, comprising: a strain plate provided so as to seal the released portion; and a strain gauge that converts the strain of the strain plate into a voltage.

The small amount ejection detecting device for the viscous liquid of the present invention comprises:
The voltage value output from the strain gauge is equal to or higher than the upper threshold, from the lower threshold to the upper threshold, by two thresholds that are arbitrarily specified lower and upper thresholds, and It is characterized in that it has a signal separating means for separating into three stages equal to or lower than the lower limit threshold value, and a judging means for judging whether or not there is an abnormality in ejection by a signal from the signal separating means.

Further, according to the present invention for achieving the above object, a strain plate provided so as to release a part of a flow path through which a viscous liquid passes and seal the released part, and the strain plate. A strain gauge for converting a strain into a voltage, a timer for elapse of an arbitrary fixed time from the time when the voltage value output from the strain gauge becomes equal to or higher than an arbitrarily specified fixed value, and a timer provided in the middle of the flow path And a valve that opens and closes the flow of the viscous liquid, and closes the valve when the timer expires.

[0016]

The present invention constructed as described above operates as follows for each claim. First, according to the first aspect of the present invention, when the viscous liquid flows in the flow passage, the pressure inside the flow passage and the flow passage resistance cause the liquid to spread the strain plate provided in the open portion. Therefore, the strain plate is distorted. By converting this strain into a voltage with a strain gauge, the ejection of a very small amount of liquid is detected.

According to a second aspect of the present invention, the voltage obtained from the strain gauge is separated into three levels by the signal separating means by the two threshold values of the upper limit and the lower limit, and the judging means separates the voltage from the signal separating means. If the signal is a signal indicating a stage above the upper limit, it is judged that the viscous liquid is discharged for some reason and the pressure in the flow path is high, and the stage between the lower and upper limits is determined. If it is the signal shown, it is judged that the viscous liquid is being discharged at an appropriate pressure, and if it is a signal showing a stage below the lower limit, it is judged that the viscous liquid is not being discharged.

According to the third aspect of the present invention, when the viscous liquid flows in the flow passage, the pressure inside the flow passage and the flow passage resistance cause the liquid to spread the strain plate provided in the open portion. Therefore, the strain plate is distorted. This strain is converted into a voltage by a strain gauge, and a timer elapses from the time when this voltage value exceeds a certain value, that is, the time when the liquid is actually ejected, and the valve is closed after the elapse of a certain time. Thus, the discharge amount of the viscous liquid is accurately controlled.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. The members having the same function are designated by the same reference numerals.

FIG. 1 is a perspective view showing the external appearance of a viscous liquid minute discharge detection device to which the present invention is applied, FIG. 2 is a partial sectional perspective view of this device, and FIG. 3 is an exploded view of this device. Is.

In this discharge detecting device, a flow path 11 through which a viscous liquid passes is formed in the main body block 1, a part of the flow path 11 is released 12, and the open portion 12 is formed.
A strain plate 3 made of spring steel having a thickness of 0.1 mm is provided so as to seal the sheet. In order to prevent outflow of liquid between the strain plate 3 and the main body block 1 and to prevent reaction sticking between the seal plate and the strain plate 3 (made of steel), which will be described later, which is the purpose of use in this embodiment. A Teflon packing 2 having a thickness of 0.1 mm is inserted.

The strain plate 3, together with the packing 2, is attached to the main body block 1 from above by means of a pressing plate 4 whose inside is hollowed out, and the upper part of the pressing plate 4 is covered by a cover 5.

A strain gauge 6 made of a piezoelectric conversion element for converting the deformation pressure of the strain plate 3 into a voltage is attached to the strain plate 3, and a signal of the strain gauge 6 passes through a signal line 7. It is supplied to the connector 8 and connected to the external signal line 9.

1 and 2, the cover 5 is removed so that the strain plate 3 inside can be seen.

The flow of the viscous liquid of this detecting device enters from the IN side and exits to the OUT side as shown by the arrow in the figure. Then, when the viscous liquid is discharged and flows in the flow path 11,
Due to the internal pressure generated by the interaction between the flow path resistance due to the viscosity of the liquid and the flow path diameter difference with the outlet tip, the strain plate 3
The force that pushes and spreads acts on the strain plate 3 to cause strain. The strain generated in the strain plate 3 is converted into a voltage by the strain gauge 6, and the presence or absence of ejection is detected.

The viscosity of the viscous liquid that can be detected by this detection device is, for example, about 1500 to 3000 poises. If the viscosity is lower than 1500 poises,
This device is not incapable of detecting the discharge of a liquid having a viscosity less than that, but if it is less than such a viscosity, it can be easily detected by a simple U-shaped tube, etc. Is. On the other hand, when it exceeds 3000 poise, the viscosity is too high and the fluidity is too small to be detected.

Further, the range of the discharge amount that can be detected by this device is different depending on the thickness of the strain plate to be used, the spring rigidity, the area of the portion that is in contact with the liquid, etc., and is not particularly limited, but as in this embodiment. When a spring steel with a thickness of 0.1 mm is used, the amount is around 0.03 ml, preferably 0.01
It is suitable to use for measurement of about 0.1 ml. This is because, in the case of the thickness of the strain plate in the present embodiment, if the flow rate becomes too high, the pressure applied to the strain plate may become too large and accurate measurement may not be possible. On the contrary, if the strength of the strain plate is increased in order to increase the upper limit of the measurement range, it becomes impossible to detect an extremely small amount of ejection. Further, in the present embodiment, Teflon packing is used to cover the entire surface of the strain plate in order to prevent reaction sticking between the sealant and the strain plate. If there is no problem such as this, it is not necessary to cover the entire surface of the strain plate with this Teflon packing, and the liquid may directly contact the strain plate. In that case, it becomes possible to detect a smaller amount of ejection.

Next, a description will be given of an embodiment in which the discharge detecting device is installed in a sealant applying device to detect the presence / absence of discharge of the sealant and to control the discharge amount.

FIG. 4 is a drawing of a sealant applying device using the discharge detecting device according to the above-mentioned embodiment, and a tube extending from the seal valve 22 to the nozzle 24 of the above-mentioned sealant applying device (shown in FIG. 8). Since the discharge detection device is provided in the middle of 28, and the other configuration is the same as that already described, the description thereof will be omitted.

FIG. 5 is a block diagram showing a configuration relating to the control of this sealant applying device. In this sealant applying device, an electric signal from the discharge detecting device 10 is amplified by an amplifier 40 and enters a comparator 41 which is a signal separating means for separating into three stages by two threshold values, and an output from the comparator 41. Based on the above, the sequencer 42, which is a judging means, judges the signal of each stage, controls the start of the timers 29 and 30 over time, and controls the opening and closing of the seal valve 22 to apply the sealant. The comparator 41 used here separates the voltage value from the amplifier 40 into three stages, and when the voltage is less than the lower threshold value as a reference,
It has a FF, a Low output that is turned on when it is higher, and a Hi output that is turned off when it is lower than the upper threshold and is turned on when it is higher than the upper threshold. The upper and lower thresholds are arbitrarily defined. For example, for the lower threshold, the voltage when discharge is reliably stopped and the upper threshold are high pressures that cause defects. Voltage.

Here, the signal from the strain gauge 6 (the signal after being amplified by the amplifier 40) due to the discharge of the sealant, the output signal from the comparator 41, the operation of the timers 29 and 30, and the opening / closing timing of the seal valve 22. Will be described.

FIG. 6 shows the voltage from the strain gauge 6 (the voltage after being amplified by the amplifier 40, the same applies hereinafter) and the timer 2.
9 is a timing chart showing the operations of 9 and 30, the output of the comparator 41, and the opening / closing of the seal valve 22. Since the timers 29 and 30 operate in synchronization with each other, when the seal valve 22 shown in one chart in the figure is opened, the seal agent is discharged from the tip of the nozzle 24 from the tank 26 containing the seal agent. Since the sealant is viscous, it will not be discharged immediately and there will be a slight time lag. Therefore, as shown in the figure, the voltage from the strain gauge 6 gradually rises after the seal valve 22 is opened. Then, when the lower limit threshold value is exceeded, the output Low of the comparator 41 is turned on. At this time, the output Hi of the comparator 41 is OFF. Then, at the same time when the Low output is turned on, the timers 29 and 30 start the lapse of time. Time timer 2 specified arbitrarily
After the passage of time according to 9 and 30, the seal valve 2
Close 2 As a result, it can be seen from the voltage of the strain gauge that the discharge from the tip of the nozzle 24 is gradually disappearing.

The opening and closing of the seal valve 22 and the operations of the timers 29 and 30 are controlled by the Lo from the comparator 41.
Sequencer 42 based on the w and Hi outputs.

The control of the sealant application will be described below with reference to the flow chart shown in FIG.

First, when the discharge detection device 10 operates, it is judged from the Low output from the comparator 41 whether or not the discharge of the sealing agent from the tip of the nozzle 24 is stopped without fail (S1). In this step S1, if it is visually confirmed that the sealant is not ejected, conversely, it may be used for diagnosing whether the small amount ejection detecting device 10 is operating properly. At this time, if the Low output is not OFF, there is an abnormality, and an alarm is sounded (S12). If an alarm occurs in this state, the valve is not closed completely and the seed agent is leaking, or if the seed agent is audible by visual inspection even though the seed agent is not ejected, the discharge detection The device 10 may be defective.

Next, when it is confirmed in step S1 that the sequencer 41 operates normally, the air valve 23 is opened so that the sequencer 41 opens the seal valve 22, and at the same time, the air valve 25 for driving the air rotating tool 30 is opened. Open (S2).

When the Low output is turned on (S
3), the timers 29 and 30 are started (S5).
If the Low output is not turned on in step S3, the Low output is monitored for 2 seconds, and the O
If it does not reach N, an alarm is sounded (S13).
If an alarm occurs in this state, the seal valve 22
It is considered that the cause is that the valve does not open, the pressure of the liquid is abnormal (insufficient pressure), the seal valve 22 and the tubes 27 and 28 are clogged. The 2 seconds in step S4 is a time to wait for a time lag from the opening of the seal valve 22 to the actual discharge of the sealing agent, which is appropriately changed depending on the viscosity of the viscous liquid (sealing agent). To do.

Next, in steps S6, S7 and S8, the Hi output and the Low output of the comparator 41 are monitored until the timers 29 and 30 elapse (time up), and the Hi output is turned on or the low output is turned on.
When it is no longer an alarm (S14 or S15)
Sound. When the Hi output is turned on and an alarm is generated (S14), it is considered that the seal valve 22 and the tube internal pressure are abnormally high. However, in this case, the liquid is being discharged. Also, Low output is O
When it is no longer N, it means that the discharge is not performed, and the seal valve 22 and the tubes 27, 28
May be blocked.

When the timers 29 and 30 have elapsed (S8), the air valve 23 is closed to close the seal valve 22 (S9).

Next, it waits for 2 seconds (S10) and judges whether the Low output of the comparator is OFF (S1).
1) If it does not turn off, an alarm sounds (S1)
6). The alarm in this state may be an abnormality in which the seal valve 22 does not close. The 2 seconds in step S10 is a time for waiting a time lag after the sealing valve 22 is closed until the discharge of the sealing agent is actually stopped, which is appropriately changed depending on the viscosity of the viscous liquid (sealing agent). To do.

As described above, by using the output of the discharge detection device for the sealant application control by the sequencer, the timer can be started from the time when the sealant is actually discharged, and the sealant is wasted. Can be omitted.

[0042]

As described above, according to the present invention, each of the claims has the following effects.

According to the first aspect of the present invention, a release portion is provided in a part of the flow path of the viscous liquid, and the strain plate and the strain of the strain plate are converted into a voltage in the release portion. By providing the strain gauge, it is possible to detect the presence / absence of a small amount of discharge of, for example, about 0.1 ml or less.

According to the second aspect of the present invention, by dividing the voltage value from the strain gauge into three stages,
It is possible to easily know at which stage the voltage is being output, and it is possible to monitor various discharge abnormalities of the viscous liquid.

Further, according to the invention of claim 3,
An open part is provided in a part of the flow path of the viscous liquid, a strain plate and a strain gauge that converts the strain of this strain plate into a voltage are provided in this open part, and the voltage from this strain gauge is above a certain value. When it becomes, the timer is operated and the valve is opened and closed by this timer, so it is possible to pass from the time when the viscous liquid is actually discharged, and the discharge amount of the viscous liquid is accurately controlled. become able to.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of a small amount discharge detection device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional perspective view showing the structure of the small amount discharge detection device according to the above embodiment.

FIG. 3 is an exploded perspective view showing a configuration of a micro discharge detection device according to the above embodiment.

FIG. 4 is a diagram showing a configuration of a sealant applying device using the micro-discharge detection device according to the above-described embodiment.

FIG. 5 is a block diagram showing a control system of the sealant applying apparatus according to the above embodiment.

FIG. 6 is a view for explaining control timings in the sealant applying device according to the above embodiment.

FIG. 7 is a flowchart showing a control flow of the sealant applying device according to the above embodiment.

FIG. 8 is a view showing a configuration of a conventional sealant applying device.

FIG. 9 is a view showing an example of a sealing agent applying step.

[Explanation of symbols]

1 ... Main body block, 2 ... Packing, 3 ... Distorted plate, 4 ...
Pressing plate, 5 ... Cover, 6 ... Strain gauge, 7 ... Signal line,
8 ... Connector, 9 ... External signal line, 10 ... Minute discharge detection device, 11 ... Flow path, 12 ... Opening portion, 20 ... Air source, 2
1 sealant tank, 22 ... Seal valve, 23, 25 ...
Air valve, 24 ... Nozzle, 29, 30 timer, 40
... amplifier, 41 ... comparator, 42 ... sequencer.

Claims (3)

(57) [Claims] 1. A strain plate provided so as to open a part of a flow path through which a viscous liquid passes and seal the open part, and a strain gauge for converting a strain of the strain plate into a voltage. A device for detecting a minute amount of a viscous liquid characterized by having. 2. The voltage value output from the strain gauge is set to an upper limit threshold or more and an upper limit from a lower threshold by two thresholds, a lower threshold and an upper threshold, which are arbitrarily defined. 7. A signal separating means for separating the threshold value and a lower threshold value in three stages, and a judging means for judging whether or not there is an abnormal discharge by a signal from the signal separating means. 1
The minute amount ejection detection device for the viscous liquid described. 3. A strain plate provided so as to open a part of a flow path through which the viscous liquid passes and seal the open part, and a strain gauge for converting a strain of the strain plate into a voltage. A timer that elapses an arbitrary fixed time from the time when the voltage value output from the strain gauge becomes equal to or higher than a predetermined value that is arbitrarily specified, and a valve that opens and closes the flow of the viscous liquid provided in the middle of the flow path, And a discharge amount management device for the viscous liquid, wherein the valve is closed when the timer expires.