JP2809751B2 - Paint gun discharge control system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint discharge amount of a manual type paint gun for discharging a so-called two-liquid type paint which is applied after mixing a main agent and a curing agent. It relates to a control device.

2. Description of the Related Art For example, in a coating gun to which a two-liquid (base agent and curing agent) mixed type urethane paint is to be discharged, a discharge amount control method as shown in FIGS. 3 and 4 is employed.

FIG. 3 shows an example of automatic painting by an automatic painting machine or a robot.
Main agent supply path 35 including 2 and positive displacement gear pumps 33 and 34
The main agent and the curing agent, each of which has been quantitatively supplied separately from the curing agent supply path 36, are completely mixed at a predetermined ratio by a mixing valve 37, and then spray-painted by a painting gun 38, and a coating pattern set in advance. By controlling the rotation speed of the gear pumps 33 and 34 according to the coating conditions of the
The discharge amount from 8 is controlled. 39 and 40 are supply sources of the main agent and the curing agent, and 41 and 42 are pressure gauges with output terminals.

FIG. 4 is based on the premise that manual painting is performed, and the color change valves 31 and 32 and the gear pump 3 are used.
3, 34 and a hardener supply path 36
The main agent and the curing agent, which are respectively supplied in a fixed amount from each other, are injected into a paint container 44 attached to a manual-type painting gun 43 for painting.

Problems to be Solved by the Invention However, in the former method shown in FIG. 3, since only the purpose of automatic painting is intended, painting conditions such as painting timing and discharge amount are predicted in advance as in manual painting. If not, it cannot be used.

In the latter method shown in FIG. 4, the maximum discharge amount when the trigger 45 of the coating gun 43 is pulled to the maximum position is uniquely determined, but the discharge is performed at an intermediate position according to the operation amount of the trigger 45. In order to adjust the amount, it is necessary to rely on the operator's feeling, and it is difficult to finely adjust the discharge amount. Therefore, when an attempt is made to adjust the discharge amount, not only does the discharge amount suddenly change and the coating film thickness varies, but also the coating film thickness tends to vary due to individual differences, which limits the improvement of coating quality.

The present invention has been made in view of the above-described problems, and an object of the present invention is to make it possible to continuously and smoothly variably control the discharge amount by a worker's will while using a manual type coating gun. It is an object of the present invention to provide an improved paint discharge amount control device.

Means for Solving the Problems In the present invention, the main agent and the curing agent respectively supplied from the main agent supply path and the curing agent supply path individually provided with the gear pumps for the fixed amount supply are mixed at a predetermined ratio by a mixing valve. The above paint is supplied to a manual type paint gun, and a valve incorporated in the paint gun is opened and closed by operating a trigger of the paint gun to control the discharge amount of the paint. Pressure detection means for detecting the pressure of the paint supply path between the pressure pump and the pressure detection means for variably controlling the supply amounts of the base material and the curing agent from each of the gear pumps based on the pressure detected by the pressure detection means. Control means for performing feedback control of the pump rotation speed.

According to the present invention, when the discharge amount changes due to the trigger operation of the coating gun, the pressure in the paint supply path changes according to the change in the discharge amount. When this pressure change is detected by the pressure detecting means, the control means changes the number of revolutions of the gear pump, which is the fixed-quantity supply device, so that the discharge amount is optimal for the pressure.

As a result, the discharge amount follows continuously and smoothly according to a change in the operation amount of the trigger of the coating gun according to the will of the operator.

Embodiment FIG. 1 is a structural explanatory view showing an embodiment of the present invention.
Is a supply source of a main agent and a curing agent, 3 is a main agent supply path, and 4 is a curing agent supply path. A pressure gauge with an output terminal in the main agent supply path 3 and the curing agent supply path 4 in order from the upstream side
5, 6, color change valves 7, 8 and positive displacement gear pumps 9, 10 as a fixed amount supply device are interposed. Then, the main agent and the curing agent supplied by the supply paths 3 and 4 are mixed at a predetermined ratio by the mixing valve 11, and then supplied to the coating gun 13 through the paint supply path 12.

The coating gun 13 is a known air spray type having a built-in needle valve. The needle valve is displaced in conjunction with the operation of the trigger 14 to adjust the nozzle opening.

A pressure sensor 15 as a pressure detecting means is provided in the paint supply path 12.
The pressure sensor 15 is connected to the paint supply path 12.
The pressure inside the gear pump is detected and the detected pressure P is
Is output to a controller 16 as control means for controlling the rotation of the motor.

The controller 16 is configured with, for example, a microcomputer or the like as a main component.The controller 16 controls the amount of supply from each of the gear pumps 9, 10 required when the needle valve is fully opened by operating the trigger 14.
In addition to the preset number of rotations of 10, the gear pump
Since there is a correlation between the paint supply amount from the paint supply path 9, 9 and the pressure P of the paint supply path 12, the set rotation speed of the gear pumps 9, 10 is determined based on a correction condition set in advance according to the detected pressure P. Is provided with a function of increasing or decreasing the correction.

In the paint discharge amount control device configured as described above, when the trigger 14 of the coating gun 13 is pulled to the maximum stroke limit position at the time of coating to fully open the needle valve,
Air flow switch of atomizing air supply passage (not shown) is ON
Under the condition, the gear pumps 9 and 10 are driven to rotate at the above set number of rotations. As a result, gear pumps 9, 10
The main agent and curing agent sent out by the mixing valve
After being mixed at a predetermined ratio at 11, the mixture is discharged from the coating gun 13.

On the other hand, when it is desired to reduce the discharge amount during painting, the trigger 14 is returned to, for example, about half of the total stroke according to the worker's will. As a result, the discharge amount of the paint discharged from the coating gun 13 is limited to about half of the fully opened state, and the pressure P in the paint supply path 12 increases accordingly. Then, the pressure P at this time is detected by the pressure sensor 15, and the detected pressure P is input to the controller 16.

The controller 16 performs a predetermined calculation based on the above detected pressure P, and based on the correction conditions set in advance, the gear pumps 9, 10 are controlled so that the supply amount from the gear pumps 9, 10 becomes smaller than the set supply amount. The rotation speed of is corrected and controlled.

Conversely, when the detected pressure P becomes lower than the supply amount from each gear pump 9, 10, each gear pump 9 is set so that the supply amount from the gear pumps 9, 10 increases with the previously set rotation speed being the maximum limit. , 10 are corrected and controlled.

In addition, when the painting is completed, the operation of the trigger 14 is stopped to turn off the airflow switch, so that the driving of the gear pumps 9 and 10 is stopped on the condition that the airflow switch is turned off.

As described above, according to the present embodiment, the rotation speeds of the gear pumps 9 and 10 as the quantitative supply devices continuously and smoothly follow a change in the stroke of the trigger 14, that is, a change in the opening of the needle valve according to the will of the operator, Fine discharge amount control can be performed while maintaining the mixing accuracy of the main agent and the curing agent.

Here, as shown in FIG. 2, pressure sensors 17 and 18 are provided on the downstream side of the gear pumps 9 and 10 separately from the pressure gauges 5 and 6 on the upstream side of the gear pumps 9 and 10, respectively. Pressure P ₁ , P
Based on the correlation between the difference ΔP between the pressures ₁₁ and the outlet side pressures P ₂ , P ₁₂ and the pump discharge amount error (actual discharge amount−theoretical discharge amount) ΔQ, the gear pumps 9 and 10 When the rotation speed is corrected, the supply accuracy from the gear pumps 9 and 10 can be further increased.

Advantageous Effects of the Invention As described above, according to the present invention, the pressure of the paint supply path in the preceding stage of the coating gun is detected, and the supply amounts of the main agent and the curing agent from the gear pump are variably controlled based on the detected pressure. By doing so, it is possible to perform continuous and smooth discharge amount control as well as fine discharge amount adjustment by the worker's will, even though it is a manual type coating gun. As a result, it is possible to eliminate a sudden change in the discharge amount and a variation in the discharge amount due to individual differences, thereby making the coating film thickness uniform and contributing greatly to the improvement of the coating quality.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a configuration showing an embodiment of the present invention, FIG. 2 is an explanatory view of a configuration showing another embodiment of the present invention, and FIGS. 3 and 4 are examples of a conventional paint discharge amount control device. FIG. DESCRIPTION OF SYMBOLS 1 ... Main agent supply source 2, ... Hardener supply source 3, ... Main agent supply path 4, ... Hardener supply path 9,10 ... Gear pump as fixed-quantity supply device, 11 ... Mixing valve, 12 ... …
Paint supply path, 13 ... Painting gun, 14 ... Trigger, 15 ...
... pressure sensor as pressure detection means, 16 ... controller as control means.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-111966 (JP, A) JP-A-2-298375 (JP, A) JP-A-63-111965 (JP, A) JP-A 64-64 22368 (JP, A) JP-A-64-85159 (JP, A) JP-A-55-163119 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05B 7/00-7 / 32 B05B 13/00 B05C 11/10

Claims (1)

(57) [Claims] 1. A main valve and a curing agent respectively supplied from a main agent supply path and a curing agent supply path, which are individually provided with a gear pump for a fixed amount supply, are mixed at a predetermined ratio by a mixing valve, and then the paint is manually operated. A paint supply path between the mixing valve and the paint gun in a device that supplies to the paint gun of the type and controls the paint discharge amount by opening and closing the valve built in the paint gun by operating the trigger of the paint gun Pressure detection means for detecting the pressure of the pump, and feedback control of the pump rotation speed according to the detection pressure in order to variably control the supply amounts of the main agent and the curing agent from each gear pump based on the pressure detected by the pressure detection means. A paint discharge amount control device for a coating gun, comprising: control means;