JPH0230057Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention supplies coating liquid to a coating device equipped with a positive displacement slave pump of the same type by a positive displacement parent pump provided on the side of the coating liquid supply tank. This device relates to a quantitative coating device that discharges the amount of coating liquid from the coating device in exact proportion to the rotational speed of the pump when performing coating work using a robot. The present invention relates to a fixed-quantity coating device that is effective for

[Conventional technology]

If the coating liquid supply tank and the coating equipment are far apart, or if the coating liquid is supplied to multiple coating devices at the same time from a common coating liquid supply tank, the coating liquid supply tank may be used. The pump provided on the side (parent pump) requires a pump with a higher discharge pressure than the pump provided in the coating device (child pump).

In such cases, both the parent pump and the slave pump are generally positive displacement pumps, such as single-screw pumps, whose rotor operating time (rotation speed) is proportional to the amount of liquid discharged, and are installed in the coating equipment. The pressure sensor senses the internal pressure of the coating device and controls the drive of the main pump to maintain the internal pressure of the coating device within a predetermined pressure range.

[The problem that the idea aims to solve]

However, according to the conventional coating device described above, even if the parent pump starts driving when the internal pressure of the coating device drops to the lower limit setting pressure, the internal pressure of the coating device does not rise immediately, and the coating liquid from the coating device There may be interruptions. Conversely, even if you stop driving the parent pump when the internal pressure of the coating device rises to the upper limit set pressure, the internal pressure of the coating device does not drop immediately, and the amount of liquid discharged from the coating device increases, or the slave pump There was also a risk that the coating liquid might leak out when the machine was in a stopped state.

Additionally, the present applicant has applied for a coating device of this type that can be incorporated into a robot and automatically apply a fixed amount of material along the scheduled coating line of the workpiece, but this device has a coating device that can be installed in a robot to automatically apply a fixed amount of material along the planned coating line of the workpiece. This system controls the pump driving speed of the coating device so that the thickness of the coating line is always constant regardless of changes in the moving speed of the robot.

Therefore, in order to keep the thickness of the coating line constant, it is necessary to ensure that the amount of liquid discharged from the coating device is accurately matched to the pump drive speed. It is required to maintain the internal pressure within a predetermined pressure range.

This idea was created in view of the above points, and the internal pressure of the coating device can always be maintained within the set pressure range regardless of whether the parent pump is running or stopped, and there is no leakage of the coating liquid, ensuring a reliable and stable operation. It is an object of the present invention to provide a quantitative coating device that discharges a fixed amount of coating liquid.

(Means for solving the problem) The gist of this invention to achieve the above-mentioned purpose is to supply the coating liquid sent from the coating liquid supply tank via the positive displacement parent pump to the coating device. , in a quantitative coating device that discharges the coating liquid through a positive displacement sub-pump provided in the coating device, a communication port is provided in the peripheral wall of the intermediate portion of the main body of the coating device, and the communication port communicates with the inside and outside of the device main body; At the same time, a cylindrical expanding body is fitted onto the elastic sleeve, and the inside of the expanding diameter body is separated from the inside of the device main body by the elastic sleeve. forming a pressurized chamber, communicating with the pressurizing chamber and connecting a pressurized fluid source via a switching valve, detecting an upper limit set pressure and a lower limit set pressure in the coating device, and outputting a signal. The quantitative coating device is characterized in that it is equipped with a pressure detector and is configured to operate and control the parent pump and the switching valve based on the output from the detector.

[Effect]

According to the quantitative coating device of this invention, when the internal pressure of the coating device reaches the upper limit set pressure and is detected by the pressure detector while the parent pump is supplying the coating liquid to the coating device, the pressure detector The output from the main pump stops driving the main pump, and at the same time the switching valve switches to open the pressurized chamber to the atmosphere.

Even if the parent pump is driven as described above, the internal pressure of the applicator tends to rise further due to residual pressure immediately after it stops, but this internal pressure acts on the elastic sleeve through the communication hole in the main body of the device, causing it to rise to the atmosphere. It expands toward the open pressurized chamber to increase the volume inside the coating device and suppress the increase in internal pressure.

When the internal pressure of the applicator reaches the lower limit set pressure and this is detected by the detector, the output from the detector starts driving the main pump, and at the same time the switching valve switches and pressurized fluid is supplied to the pressurizing chamber. Pressurized fluid is introduced from a source.

Therefore, immediately after the parent pump starts driving, there is a time lag before the pressurizing force from the parent pump reaches the coating device, so the internal pressure of the coating device cannot increase during this time, and if the coating device is used in this state, the coating device will The internal pressure of the coating device attempts to further decrease below the lower limit set pressure, but the introduction of pressurized fluid into the pressurizing chamber causes the elastic sleeve to contract, reducing the volume within the applicator and preventing the internal pressure from decreasing. . In this way, the internal pressure of the coating device is always maintained within the set pressure range, and a proper coating operation is performed by reliably and stably discharging a fixed amount of coating liquid.

〔Example〕

Hereinafter, embodiments of this invention will be described in detail based on the drawings.

FIG. 1 is a sectional view showing an embodiment of the quantitative coating apparatus according to the invention, FIG. 2 is a front view thereof, and FIG. 3 is an overall system diagram of the quantitative coating apparatus.

In the figure, reference numeral 1 denotes the main body of the apparatus, in which a coating liquid supply port 2 is opened on the peripheral wall of one end, and a positive displacement slave pump 4 with a coating liquid discharge nozzle 4c attached to the tip is connected to the other end 3. It is set up. This girl pump 4
A uniaxial screw pump is used, which consists of a female screw type stator 4a having a female screw shaft with an oval cross section and a male screw type rotor 4b rotating within a hole of this stator 4a, and a motor 5 fixed at the end of the device body 1. The rotor 4b of the pump 4 is connected via a connecting rod 5a. Note that this motor 5 uses a servo motor with variable rotation speed.

Reference numeral 6 denotes slit-like communication holes opened in the circumferential wall of the cylindrical intermediate portion of the device main body 1, which are provided at a plurality of locations at intervals in the circumferential direction. Reference numeral 7 denotes an elastic sleeve made of rubber which is arranged on the main body 1 of the apparatus by surrounding the communication hole 6, and 8 is fitted onto the elastic sleeve 7 as an enlarged diameter part of the side peripheral wall of the main body 1 of the apparatus. It is a cylindrical expanded diameter body, and both ends of the elastic sleeve 7 are pressed and fixed against the device main body 1 in an airtight manner by opening edges 8a and 8b at both ends of the expanded diameter body 8.
A pressurized chamber 9 is formed therein, which is separated from the inside of the apparatus main body 1 by an elastic sleeve 7.

Reference numeral 10 denotes an air compressor that serves as a pressurized fluid source, and an electromagnetic switching valve 1 is connected to a pressurized fluid inlet/outlet 8c provided in the enlarged diameter body 8 so that the discharge port of the compressor 10 communicates with the pressurizing chamber 9.
By switching the electromagnetic switching valve 11, the pressurizing chamber 9 is opened to the atmosphere and compressed air from the compressor 10 is introduced.

A pressure detector 12 is arranged near the coating liquid supply port 2 of the apparatus main body 1 and detects the internal pressure of the apparatus main body 1. The pressure detector 12 detects the upper limit set pressure and the lower limit set pressure of the apparatus main body 1 and outputs a signal.

Reference numeral 13 denotes a positive displacement parent pump that supplies the coating liquid from the coating liquid supply tank 15 to the main body 1 of the apparatus, which uses a single screw pump of the same type as the slave pump 4 and is driven by the motor 14. The discharge port is connected to the coating liquid supply port 2 of the main body 1 of the apparatus.

Reference numeral 16 denotes a control device, and this control device 16 controls the motors 5, 14, the electromagnetic switching valve 11, and the pressure detector 1.
2, when the internal pressure of the main body 1 reaches the upper limit set pressure, the motor 14 of the main pump 13 is stopped by the signal output from the pressure detector 12, and at the same time the switching valve 11 is switched to reduce the pressure. The chamber 9 is opened to the atmosphere, and when the internal pressure of the main body 1 reaches the lower limit setting pressure, the motor 14 of the main pump 13 is driven by the signal output from the pressure detector 12, and at the same time, the switching valve 11 is returned to its original state. It generates an operation command to switch to and introduce pressurized air into the pressure chamber 9.

Therefore, after the internal pressure of the coating device, that is, the device main body 1 reaches the upper limit set pressure and the motor 14 of the main pump 13 stops, if the internal pressure of the device main body 1 attempts to rise beyond the upper limit set pressure due to residual pressure, etc. In response to this internal pressure, the elastic sleeve 7 expands into the pressure chamber 9 which is open to the atmosphere, thereby suppressing an increase in the internal pressure of the apparatus main body 1.

In addition, the internal pressure of the device main body 1 reaches the lower limit set pressure,
After the parent pump 13 starts driving, the parent pump 1
There is a time lag until the pressurizing force from 3 reaches the device main body 1. Therefore, if the applicator is still in use during this period, the internal pressure of the main body 1 of the apparatus tends to fall further below the lower limit set pressure, but at the same time as the main pump 13 is driven, the switching valve 11 is switched and the pressure in the pressurizing chamber 9 is reduced. Since pressurized air with a pressure slightly higher than the internal pressure of the device main body 1 is introduced from the air compressor 10, the elastic sleeve 7 contracts in response to this pressure, raising the internal pressure of the device main body 1 higher than the lower limit set pressure. It is something to do. (4th
(See figure) In this way, the internal pressure of the device main body 1, that is, the pressure on the sub pump 4 suction side of the device main body 1, is always maintained between the upper limit set pressure and the lower limit set pressure.
The coating liquid is discharged under appropriate pressure conditions in a manner that accurately matches the rotational speed of the rotor 4b of the slave pump 4.

(Effects) As explained above, the quantitative coating device of this invention provides the following effects.

(1) The internal pressure of the coating device can always be maintained within the set pressure range regardless of whether the parent pump is running or stopped, so there is no leakage of coating liquid and the rotational speed of the positive displacement slave pump installed in the coating device can be maintained. A precisely proportionate amount of the coating liquid is discharged, so that uniform coating can be achieved on the object to be coated. In addition, by storing the coating liquid in a sealed coating liquid supply tank, it is possible to eliminate contact with the outside air.
Even if a coating liquid that hardens easily, such as an adhesive, is used, the coating liquid will not solidify during the coating operation, and the partially solidified coating liquid will not be applied to the object to be coated.

(2) Even when using a common coating liquid supply tank and simultaneously supplying coating liquid to multiple coating devices using one main pump, it is especially important to avoid using other accumulators (pressure adjustment devices). However, each coating device can be freely used for quantitative coating.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the quantitative coating device according to this invention, Fig. 2 is a front view of the same, Fig. 3 is an overall system diagram of the quantitative coating device, and the upper part of Fig. 4a is a conventional quantitative coating device. A graph showing how the internal pressure changes due to the device,
The lower part of the figure is a graph showing the pressurization or depressurization status of the internal pressure of the quantitative coating device using the pressure chamber of this invention.
is a graph showing changes in internal pressure due to the quantitative coating device of this invention. 1...Device main body, 2...Coating liquid supply port, 3...
Opening, 4... Child pump, 4c... Discharge port, 7...
Elastic sleeve, 8... Expanded body, 8c... Pressurized fluid inlet/outlet, 9... Pressurizing chamber, 10... Air compressor,
11...Switching valve, 12...Pressure detector, 13...
Parent pump, 15... Coating liquid supply tank.

Claims (1)

[Scope of utility model registration request] In the quantitative coating apparatus, the coating liquid is supplied from the coating liquid supply tank via a positive displacement parent pump to the coating apparatus, and the coating liquid is discharged via a positive displacement slave pump provided in the coating apparatus. A communication port that communicates with the inside and outside of the device body is provided in the peripheral wall of the intermediate portion of the device body, and an elastic sleeve is arranged on the device body by surrounding the communication port portion, and a cylindrical sleeve is placed on the elastic sleeve. The enlarged diameter body is fitted to form a pressurized chamber inside the enlarged diameter body that is separated from the main body of the device by an elastic sleeve, and the pressurized fluid source is communicated with the pressurized chamber via a switching valve. A pressure detector is connected and configured to detect an upper limit set pressure and a lower limit set pressure in the coating device and output a signal, and to operate and control the parent pump and the switching valve based on the output from the detector. A quantitative coating device characterized by: