JPH03127655A - Device for controlling discharge of coating from coating gun - Google Patents

Abstract

PURPOSE:To delicately, continuously and smoothly control the discharge as desired by an operator with a manual coating gun by detecting the pressure in the coating supply line of the gun and variably controlling the supply of the main agent and curing agent from a constant-quantity feeder based on the detected pressure. CONSTITUTION:When a trigger 14 of the coating gun 13 is pulled to the maximum strike in coating to fully open a needle valve, an air flow switch in an atomizing air supply passage is turned on, and pumps 9 and 10 are driven at a set speed. Consequently, the main agent and curing agent delivered by the pumps 9 and 10 are mixed by a mixing valve 11 in a specified ratio, and the mixture is discharged from the gun 13. When the discharge is reduced, the trigger 14 is returned to the half stroke, for example, hence the discharge from the gun 13 is halved, and consequently the pressure P in the coating supply line 12 is increased. The pressure P is detected by a pressure sensor 15 and inputted to a controller 16, and the speeds of the pumps 9 and 10 are controlled by the controller 16 based on the set compensating condition.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to paint discharging from a manual paint gun that discharges so-called two-component heating type paint, which is applied after mixing a base agent and a curing agent. It relates to a quantity control device.

Conventional technology For example, in a painting gun that discharges a two-component (main agent and curing agent) mixed type urethane paint, the discharge rate control method % type % as shown in Figures 3 and 4 is used. An example of automatic painting using an automatic painting machine or robot is shown, and the color change valve 31.
32 and a positive displacement gear pump 33, 34, the main agent and curing agent are supplied in fixed quantities from a main agent supply path 35 and a curing agent supply path 36, respectively, and are completely mixed at a predetermined ratio at a mixing valve 37. The amount of discharge from the paint gun 38 is controlled by controlling the rotational speed of the gear pumps 33 and 34 according to the coating conditions of a preset painting pattern. 39.40 is the source of the main agent and curing agent, 41
．． 42 is a pressure gauge with an output terminal.

Furthermore, the one shown in Fig. 4 is intended for manual painting, and a fixed amount is supplied separately from the main agent supply route 35 and hardening agent supply route 36, which are equipped with color change valves 31 and 32 and gear pumps 33 and 34. The main agent and curing agent thus prepared are injected into a paint container 44 attached to a manual paint gun 43 for painting.

Problems to be Solved by the Invention However, since the former method shown in Fig. 3 is aimed exclusively at automatic painting, it is necessary to predict painting conditions such as painting timing and discharge amount in advance, unlike manual painting. If it is not possible, it cannot be used.

In addition, in the latter method shown in FIG. 4, although the maximum discharge amount when the trigger 45 of the painting gun 43 is pulled to the maximum position is uniquely determined, the discharge amount depends on the amount of operation of the trigger 45 at an intermediate position. To adjust the amount, the operator must rely entirely on his or her senses, making it difficult to finely adjust the amount of discharge. Therefore, when trying to adjust the discharge amount, not only the discharge amount changes suddenly and the coating film thickness varies, but also variations in coating film thickness due to individual differences are likely to occur, which limits the improvement of coating quality.

The present invention was made in view of the above problems.
The object of the present invention is to provide a paint discharge amount control device which is a manually operated paint gun but can continuously and smoothly control the discharge amount according to the operator's will.

Means for Solving the Problems The present invention involves mixing a base agent and a curing agent in a predetermined ratio using a mixing valve, which are supplied from a base agent supply path and a hardening agent supply path each equipped with a metered supply device, and then mixes the paint. In a device that supplies paint to a manual paint gun, and operates a trigger on the paint gun to open and close a valve built into the paint gun to control the amount of paint discharged, the The present invention is characterized by comprising a pressure detection means for detecting the pressure in the paint supply path, and a control means for variably controlling the supply amount of the base resin and curing agent from the quantitative supply device based on the detected pressure. As the quantitative supply device, for example, a positive displacement gear pump is used.

According to the present invention, when the discharge rate of the paint gun changes due to trigger operation of the paint gun, the pressure in the paint supply path changes in accordance with the change in the discharge rate. When the pressure detection means detects this pressure change, the control means changes the rotational speed of, for example, a gear pump, which is a quantitative supply device, so that the discharge amount is optimal for that pressure.

As a result, the discharge amount continuously and smoothly follows changes in the operating amount of the coating gun according to the operator's will.

Embodiment FIG. 1 is a configuration explanatory diagram showing an embodiment of the present invention, and 1.2
is a supply source of the main agent and curing agent, 3 is a main agent supply route, and 4 is a curing agent supply route. A pressure gauge 5, 6 with an output terminal, a color change valve 7.8, and a positive displacement gear pump 9.10 as a quantitative supply device are installed in the main agent supply path 3 and the curing agent supply path 4 in order from the upstream side. ing. The main agent and curing agent supplied through each supply route 3 and 4 are mixed at a predetermined ratio by a mixing valve 11, and then passed through a paint supply route 12 to a paint gun 1.
3.

The coating gun 13 is of a known air spray type having a built-in needle valve, and in conjunction with the operation of the bird -14, the needle valve is displaced and its nozzle opening degree is adjusted.

The paint supply path 12 includes a pressure sensor L as pressure detection means.
5 is provided, and this pressure sensor 15 detects the pressure in the paint supply path 12 and transmits the detected pressure P to a controller 16 as a control means for controlling the rotation of the gear pumps 9 and 10. It has become.

For example, the controller 16 is mainly configured with a microcomputer, etc., and this controller 16 includes:
The supply amount from each gear pump 9゜lO required when the needle valve is fully opened by the -14 operation is preset as the rotation speed of each gear pump 9.10, and the paint supply from gear pump 9゜10 is also set in advance. Since there is a correlation between the amount and the pressure P of the paint supply path 12, the detected pressure P
The gear pump 9 has a function of increasing or decreasing the set rotation speed of the gear pump 9 or 10 based on correction conditions set in advance.

In the paint discharge amount control device configured in this way,
When painting, when the paint gun 13 pulls -14 to the maximum stroke limit position and fully opens the needle valve,
The air flow switch of the atomizing air supply passage (not shown) is turned to
N, and under this condition, each gear pump 9, 10 is driven to rotate at the above-mentioned set rotation speed. As a result, the main agent and curing agent sent out by the gear pump 9-10 are mixed at a predetermined ratio by the mixing valve 11 and then discharged from the coating gun 13.

On the other hand, if the operator wishes to reduce the discharge amount during painting, the operator returns the trigger 14 to, for example, about half of the total stroke. As a result, the amount of paint discharged from the paint gun 13 is limited to about half that of when it is fully opened.
Correspondingly, the pressure P within the paint supply path 12 increases.

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 detected pressure P, and adjusts each gear pump 9° IO so that the supply amount from the gear pump 9.10 is less than the set supply amount based on preset correction conditions. Correctly control the rotation speed.

Conversely, when the detected pressure P becomes lower than the supply amount from each gear pump 9, 10, each gear pump 9 is adjusted so that the supply amount from the gear pumps 9, 10 increases with the previously set rotation speed as the maximum limit. ．． Correctly control the rotation speed of lO.

Further, when finishing the painting, the above-mentioned air flow switch is turned OFF by ceasing to operate the trigger 14, and therefore, the drive of the gear pumps 9 and 10 is stopped on condition of this.

In this way, according to this embodiment, the rotational speed of the gear pumps 9 and 10, which are quantitative supply devices, continuously and smoothly follows the stroke change of the trigger 14, that is, the change in the opening degree of the needle valve, caused by the operator's will. It becomes possible to finely control the discharge amount while maintaining the mixing precision of the base resin and curing agent.

Here, as shown in FIG. 2, the gear pump 9. In addition to the pressure gauge 5.6 on the upstream side of gear pump 9, pressure sensors 17 and 18 are provided on the downstream side of gear pump 9.
0 inlet side pressure P l + P II and outlet side pressure P
Based on the correlation between the difference ΔP with IF 11 and the pump discharge amount error (actual discharge amount - theoretical discharge amount) ΔQ, the rotation speed of each gear pump 9° and 10 is corrected according to the above differential pressure ΔP. This makes it possible to further improve the accuracy of supply from the gear pumps 9 and 10.

Effects of the Invention As described above, according to the present invention, the pressure in the paint supply path upstream of the coating gun is detected, and the amount of the main agent and curing agent supplied from the quantitative supply device is variably controlled based on the detected pressure. By doing this, even though it is a manual painting gun, it is possible to not only finely adjust the discharge amount according to the will of the operator but also to perform continuous and smooth control of the discharge amount. As a result, it is possible to eliminate sudden changes in the discharge amount and variations in the discharge amount due to individual differences, making it possible to make a uniform coating film thickness and greatly contribute to improving the coating quality.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a configuration showing one embodiment of the present invention, FIG. 2 is an explanatory diagram of a configuration of another embodiment of the invention, and FIGS. 3 and 4 are examples of a conventional paint discharge amount control device. FIG. l...Main agent supply source, 2...Curing agent supply source, 3...
Main agent supply route, 4... Curing agent supply route, 9, 10...
・Gear pump as quantitative supply device, 11... Mixing valve, 12... Paint supply route, 13... Paint gun, 14... Trigger 15... Pressure sensor as pressure detection means, 16...・Controller as a control means.

Claims (1)

[Claims] (1) The base agent and curing agent supplied from the base agent supply route and the hardener supply route each equipped with a quantitative supply device are mixed at a predetermined ratio using a mixing valve, and then the paint is supplied to a manual painting gun. In a device that controls the amount of paint discharged by opening and closing a valve built into the paint gun by operating the trigger of the paint gun, the pressure is used to detect the pressure in the paint supply path between the mixing valve and the paint gun. 1. A paint discharge amount control device for a coating gun, comprising: a detection means; and a control means for variably controlling the supply amount of the base agent and curing agent from the quantitative supply device based on the detected pressure.