JPH051331Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a paint quantitative supply device that discharges a predetermined amount of paint from a spray gun onto an object to be coated, and in particular, the invention relates to a paint metering device that discharges a predetermined amount of paint from a spray gun to an object to be coated. This is to speed up the rise speed of the discharge amount when performing this.

(Prior art) For example, when applying an intermediate coat or top coat to an object to be coated, such as an automobile body, paint is discharged in a spray form from a spray gun and applied to the object. There is.

Figure 6 is a diagram showing a paint quantitative supply device conventionally used for applying intermediate and top coats to automobile bodies. A large number of main pipes 1 shown in the figure are installed. These main pipes 1 each include a number of pipes having different colors and corresponding to the colors of the paints to be applied, and pipes for supplying thinner and air for cleaning.

These main pipes 1 are connected to a color change valve CCV by a flow path 2 branched from each main pipe 1. This color change valve CCV is a three-way valve that integrates a paint valve, a cleaning valve, and an air valve. A number of gear pumps 3 corresponding to the colors of the paint to be applied are attached to the paint supply flow path 2.
These are connected by a shaft and driven by one motor 4. A spray gun 5 for applying paint is connected to a color change valve CCV by a paint discharge hose 6, and the spray gun 5 is attached to a reciprocator 7 so as to be movable up and down. Incidentally, the spray gun 5 may be attached to the arm of an industrial robot to perform painting work.

In such a paint quantitative supply device, the first
As a method, there is a method in which an inverter is used to constantly supply paint at a motor rotation speed commensurate with the discharge amount, and a three-way valve in the color change valve CCV is switched to correspond to the on/off of the spray gun 5. In this case, when discharging paint from spray gun 5, use a color change valve.
The three-way valve inside the CCV is placed on the gun side, and when the paint is stopped, the three-way valve is placed on the circulation side.

In another method, a clutch is provided between the motor 4 and the gear pump 3, and only the gear pump 3 corresponding to the paint color to be used is operated by operating the clutch.

(Problem to be solved by the invention) However, in the first method described above, all the gear pumps 3 are always driven by the motor 4, which constantly circulates the paint. In this case, the aluminum powder contained in the paint will be crushed in the gear pump 3, making it difficult to ensure sufficient finish quality.

In addition, in the other methods mentioned above, it takes a relatively long time from when the clutch is turned on until the paint is discharged by the spray gun 5, and the rise of the discharge amount is delayed. There was a problem that became noticeable when it wore out.

The present invention has been made in view of the problems of the prior art described above, and an object of the present invention is to speed up the rise in the amount of paint discharged when the spray gun starts discharging paint.

(Means for Solving the Problems) The present invention to achieve the above object connects the tip of a paint discharge hose to an on-off valve provided on a spray gun that applies paint, and is driven by a motor to discharge the paint from the paint source. In the paint discharging device, the rear end of the paint discharging hoe is connected to a switching valve connected to a gear pump that supplies the paint under pressure via a supply side flow path. A pressure sensor is provided to detect pressure, and a very low speed rotation command signal is sent to the motor in response to a signal from the device orbiting means, and the pressure of the paint in the paint discharge hose is set to the discharge pressure and a preparation pressure lower than this. and a control means for sending a high-speed rotation command signal to the motor when the opening/closing valve is opened, and causing the paint to be discharged from the spray gun at the discharge pressure. It is a device.

(Function) When the device is activated, the pressure of the paint in the paint discharge hose is between the predetermined preparation pressure and the predetermined discharge pressure, and the on-off valve, that is, the trigger valve, is activated and the spray is started. When applying paint from a gun to an object to be coated, the paint can be discharged by increasing the pressure from the preparatory pressure to the predetermined discharge pressure, so the on-off valve is activated. After that, the rising speed until the predetermined discharge pressure is reached becomes extremely fast.

(Example) Hereinafter, the present invention will be described in detail based on an illustrative example. FIG. 1 is a piping diagram showing the entire paint quantitative supply device according to an embodiment of the present invention,
A spray gun 10 for applying paint is provided with an on-off valve 11 also called a trigger valve, and the operation of this on-off valve 11 causes the spray gun 10 to apply and stop the application of paint. This on-off valve 11
The tip of a paint discharge hose 12 connected to the discharge end of the color change valve CCV is connected to. This color change valve CCV is composed of a large number of three-way valves as switching valves corresponding to the types of paint colors to be applied and the number of cleaning thinners, air, etc. For Figure 1,
Three-way valves 13a to 13d for four colors A to D, and three-way valve 1 for two types of curing agent, A type and B type.
Only 3e and 13f are shown for convenience of explanation.
A number of gear pumps 1 corresponding to each type of paint and corresponding to each type of curing agent.
4a to 14f are provided, and these are driven by one servo motor 15. For this purpose, the servo motor 15 is connected to the main shaft 17 via a power transmission section 16 consisting of a chain or the like.
Rotation is transmitted from these main shafts 17 to gear pumps 14a to 14f, respectively, by power transmission sections 18a to 18f. Each of the power transmission sections 18
A to 18f have a motor 15 and a gear pump 14a.
Clutches 19a to 19f are provided for turning on and off the interlocking with the clutches 19a to 14f.

Discharge ends of the respective gear pumps 14a to 14f and three-way valves 13 corresponding to these gear pumps.
A supply side flow path 20 is provided between the inlets a to 13f.
a to 20f are connected, and the three-way valves 13a to
Circulation channels 21a to 21f are connected between the circulation port of 13f and the inflow ends of gear pumps 14a to 14f. Each circulation channel 21a-2
Paint sources 22a to 22d are connected to 1d, and curing agent sources 22e and 22 are connected to circulation channels 21e and 21f.
f is connected. In the case shown in the figure, since a two-component mixture type is used as each paint, a static mixer 23 for mixing these is provided in the paint discharge hose 12.

When one of the three-way valves is operated to the discharge side, paint and curing agent flow into the paint discharge hose 12. In order to detect the pressure of the paint in the paint discharge hose 12, A pressure sensor 24 is provided on the paint discharge hose 12.

A device for controlling the operation of the device of the present invention shown in FIG. 1 will be explained based on FIG. 2.

The control means 30 includes device starting means 31a to 3, which are comprised of push button switches, etc., the total number of which corresponds to the type of paint color and the number of which corresponds to the type of curing agent.
1f is connected, and these starting means 31a to 31
When any of f is turned on, the apparatus shown in FIG. 1 is set to be ready for painting using paint of that color. In this state, a predetermined color for the object to be coated is selected, and the three-way valve corresponding to that color enters the paint discharging state. For example, paint source 2
When applying the paint from 2a to the object to be coated, by turning on the starting means 31a, a signal is sent from the control means 30 to the clutches 19a, 19e to turn them on. Thereafter, after a predetermined period of time has elapsed, the control means 30 sends a very low speed rotation command to the motor 15 to rotate the motor 15 at a very low speed. The rotation of this motor 15 stops when the pressure of the paint in the paint discharge hose 12 detected by the pressure sensor 24 reaches a predetermined discharge pressure. At a predetermined pre-pressure lower than , it will rotate again. As a result, when the device starting means 31a is turned on, the paint corresponding to the color is maintained within the paint discharge hose 12 between the discharge pressure and a lower preparation pressure (control pressure value).

When the on-off valve 11 is turned on, this signal is sent to the control means 30, and a signal for setting the motor 15 to a high speed rotation state is sent to the control means 3.
Sent from 0.

FIG. 3 is a flowchart showing the operating state of the device of the present invention, and FIG. 4 is an operation graph showing the operating timing of each component of the device.

The operating state of the device of the present invention will be explained with reference to these figures. For convenience of explanation, the case where the paint of color A from the paint source 22a is applied to the object will be described below.

When the starting means 31a is turned on, the clutch 19a corresponding to the color and the clutch 19 of the curing agent A are activated.
Enter e. At the same time, the color change valve
Each three-way valve 13a forming the CCV,
13e operates on the discharge side. When a predetermined time T set by a timer built into the control means 30 has elapsed from this state, the servo motor 1
5 is driven. In FIG. 4, the reason why the motor 15 is driven only for the time indicated by the symbol T is to prevent heat generation from the clutches 19a and 19e.

The rotational state of the motor 15 at this time is determined by the control means 3.
The signal from 0 causes it to rotate at an extremely low speed. As a result, the pressure of the paint within the paint discharge hose 12 gradually increases as shown in FIG. When the pressure sensor 24 detects that the pressure inside the paint discharge hose 12 has reached the discharge pressure due to this pressure increase,
The rotation of the motor 15 is stopped, and when this pressure reaches a predetermined preparatory pressure lower than the discharge pressure, the motor 15 is restarted.
Activate. The on/off operation of the motor 15 at a very low speed is repeated until the on-off valve 11 is turned on. As a result, the paint within the paint discharge hose 12 is maintained at a pressure between the discharge pressure and the preparation pressure.

In such a pressure state, the paint discharge hose 1 of the device
2 is set, open/close valve, trigger valve 1, to perform painting work on the object to be coated.
1 is turned on, the motor 15 rotates at high speed according to a signal from the control means 30. As a result, the paint source 22 is emitted from the spray gun 10.
The paint from a and the curing agent from the curing agent source 22e are mixed by the static mixer 23 and then discharged.

After painting a specific part of the car body, in preparation for painting other parts,
When the discharge of the spray gun 10 is stopped, the inside of the discharge hose 12 is maintained at a pressure higher than the predetermined preparatory pressure as described above, so paint is not supplied from the spray gun 10 again. When discharging the paint, the paint starts to be discharged from a preparatory pressure state, and the discharge amount rises quickly.

When painting of a certain color is completed or when the next painting takes a relatively long time, a discharge completion signal is sent and each clutch 19a, 19e
is turned off, the motor 15 stops, and the three-way valves 13a, 1
3e closes. Note that if each gear pump is stopped for a long period of time, paint will settle, so in order to prevent this, each three-way valve 13a is
The supply side flow paths 20a... and the circulation side flow paths 21a... are brought into communication via the supply side flow paths 20a..., and the paint can be circulated within the system.

FIG. 5 is a diagram showing a quantitative paint supply device according to another embodiment of the present invention, in which a two-component paint is used, whereas a one-component paint is used in this case. I am using it. Therefore, in this case,
Gear pump 14e for curing agent shown in FIG.
14f is not provided, and furthermore, a static mixer 23 for mixing is not used. In addition, in the illustrated embodiment, the color change valve
A large number of three-way valves are used as switching valves in the CCV, but if circulation within the system is not performed as described above, a switching valve that only performs on/off operations may be used. Further, as shown in the figure, each of the gear pumps 14a to 14f is connected to a motor 15 via a clutch 19a to 19f, so that the gear pump corresponding to the color rotates only when painting is performed. Therefore, even if metallic paint is used as a paint, the aluminum powder contained therein will not be crushed.

(Effects of the invention) As described above, according to the invention, the paint discharge hose is provided with a pressure sensor that detects the pressure of the paint therein, and the motor is rotated at an extremely low speed by a signal from the device starting means. A command signal is sent to set the pressure of the paint in the paint discharge hose between the discharge pressure and a lower preparation pressure, and when the on-off valve opens, a high speed rotation command signal is sent to the motor to control the spray gun. Since the apparatus includes a control means for discharging the paint at the discharge pressure, the pressure inside the paint discharge hose is always maintained between the preparation pressure and the discharge pressure when the apparatus is activated. become,
When discharging paint from a spray gun, the desired discharge pressure can be built up within an extremely short period of time, making it possible to improve the responsiveness of painting work.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a paint quantitative supply device according to an embodiment of the present invention, FIG. 2 is a block diagram showing the connection state of the control means, and FIG. 3 is a flowchart showing the operating state of the embodiment. FIG. 4 is an operation graph showing the same operating state, FIG. 5 is a schematic diagram showing a quantitative paint supply device according to another embodiment of the present invention, and FIG. 6 is a schematic diagram showing a conventional paint supply device. 10...Spray gun, 11...Open/close valve, 12
...Paint discharge hose, 13a-13f...Three-way valve (switching valve), 14a-14f...Gear pump, 15
... Motor, 20a to 20f ... Supply side flow path, 2
1a to 21f...Circulation flow path, 22a to 22d...
Paint source, 24... pressure sensor, 30... control means.

Claims (1)

[Scope of utility model registration request] The tip of the paint discharge hose is connected to the on-off valve provided on the spray gun that applies the paint, and the switching valve is connected via the supply flow path to a gear pump driven by a motor that supplies paint from the paint source under pressure. and the rear end of the paint discharge hose, the paint discharge hose is provided with a pressure sensor for detecting the pressure of the paint therein, and the paint discharge hose is provided with a pressure sensor that detects the pressure of the paint therein, and the motor is activated by a signal from the device starting means. A very low speed rotation command signal is sent to the motor to set the pressure of the paint in the paint discharge hose between the discharge pressure and a lower preparation pressure, and when the on-off valve opens, the motor is rotated at high speed. A quantitative paint supply device using a gear pump, comprising a control means for sending a command signal to discharge paint from the spray gun at the discharge pressure.