JPS634468B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for supplying high-viscosity paint, such as soundproof paint, to an airless paint machine such as an airless spray gun by pumping the high-viscosity paint using a paint pressure pump such as a plunger pump. .

FIG. 1 shows an example of a conventional method for supplying high viscosity paint, in which 1 is a high viscosity paint stored in a paint tank 2, and 3 is a high viscosity paint 1 containing, for example, 30 to 150
A plunger pump as a paint pressure pump that pressurizes to a high pressure of about Kg/cm ² , 4 is an air lifter that raises or lowers the plunger pump 3, 5 is a high viscosity paint connected to the plunger pump 3 and pressurized. 1 is a paint hose that supplies paint to the paint pressure feed line 7 via a valve 6, 8 is a pressure regulating tank called a surge chamber, and 9 is a paint pressure of high viscosity paint supplied through the paint pressure feed line 7 to an airless paint sprayer 10. This is a paint pressure reducing valve that adjusts to the working pressure.

A diaphragm 12 is attached to the lower end of the paint suction pipe 11 of the plunger pump 3 extending into the paint tank 2 to brush off the high viscosity paint 1 so that it does not adhere to the inner wall of the paint tank 2. By plunger pump 3
While the high viscosity paint 1 adhering to the inner wall of the paint tank 2 is brushed off by the diaphragm 12, the high viscosity paint 1 is sucked up and pressurized by the plunger pump 3, and is sent to the paint pressure feed pipe 7 through the paint hose 5. to pump. The paint pressure feed pipe 7 is extended into the paint booth 13 and supplies the high viscosity paint 1 to the airless paint sprayer 10 via the paint pressure reducing valve 9.

By the way, the high viscosity paint 1 is supplied to the airless paint sprayer 10 through such a paint pressure feed pipe 7.
is intermittently delivered from the plunger pump 3, which causes pulsation.

In order to eliminate this pulsation, a pressure regulating tank 8 is inserted into the paint pressure feed line 7 to remove a part of the paint from the bottom of the sealed container and eliminate the pulsation by using the air pressure at the top of the sealed container. The paint hose 5 connected to the plunger pump 3 is also made of, for example, a nylon tube reinforced with pressure-resistant stainless steel wire or nylon thread to provide elasticity to minimize paint pulsation.

However, in the conventional method shown in FIG.
The amount of paint discharged from zero was uneven, causing coating defects such as uneven coating.

In addition, in the conventional method, the high viscosity paint 1 is pumped by a plunger pump 3 to the airless paint sprayer 1.
This plunger pump 3 has a relatively low pressure to pump the high viscosity paint 1 through the long paint pressure feed pipe 7, so it can be connected to a single plunger pump 3. The number of airless paint sprayers 10 is limited to two or three at most. Therefore, when a large number of paint sprayers are installed in the paint booth 13, the plunger pump 3 should be adjusted accordingly. The disadvantage was that a large number of units had to be added, which increased equipment costs.

Furthermore, when using the conventional method, there was a problem in that clogging of the nozzle of the airless paint sprayer 10 could not be easily detected. In particular, since the paint flowing through the paint pressure feed pipe 7 has a high viscosity and a very small amount, it has been difficult to detect clogging of the nozzle by detecting changes in the flow rate using a flow meter or the like.

Therefore, the present invention provides a paint cylinder for temporarily storing high-viscosity paint pumped from a paint pressure-feeding pump in the paint pressure-feeding pipeline, and applies high pressure to the high-viscosity paint stored in the paint cylinder using a hydraulic cylinder. By pressurizing the paint and supplying it to the airless paint sprayer through the paint pressure feed pipeline, it is possible to connect more airless paint sprayers with one paint pressure pump than before.
In addition to reducing equipment costs by relatively reducing the number of paint pressure pumps installed, it also eliminates the pulsation that occurs when high viscosity paint is pumped by a paint pressure pump to ensure uniform paint discharge from the nozzle of an airless paint sprayer. In addition, it is an object of the present invention to provide a method for supplying a high viscosity paint that can easily detect clogging of the nozzle.

In order to achieve the above object, the present invention provides a high viscosity paint supply method for supplying high viscosity paint to an airless paint sprayer by force-feeding the high-viscosity paint using a paint pressure pump.
First, a paint cylinder is interposed in the paint pressure pipeline for pumping the high viscosity paint, and a hydraulic cylinder is provided in which the paint cylinder and its cylinder heads are separated from each other and the rod heads of the piston rods are connected to each other. The high viscosity paint pumped from the paint pressure pump is fed into the paint cylinder and temporarily stored therein, and then the piston rod of the paint cylinder is expanded by injecting hydraulic oil into the hydraulic cylinder and extending the piston rod. The paint cylinder is contracted and the high viscosity paint stored in the paint cylinder is supplied to the airless paint machine through the paint pressure feed pipe.

EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described with reference to specific embodiments shown in the drawings.

FIG. 2 is a system diagram showing an example of the high viscosity paint supply method according to the present invention, and parts common to those in FIG. 1 are given the same reference numerals and detailed explanation thereof will be omitted.

In FIG. 2, reference numeral 20 denotes a check valve 21 that protects the plunger pump 3 by preventing backflow of paint.
The electromagnetic switching valves 22 and 23 inserted between the paint pressure feed line 7 connected to the paint hose 5 via the paint hose 5 and the paint pressure feed line 7' connected to the airless paint sprayer 10 are electromagnetic changeover valves 22 and 23. The paint cylinders 24 and 25, which are interposed between the paint pressure feed lines 7 and 7' via the valve 20, are hydraulic cylinders whose cylinder heads are arranged to face and be spaced apart from the cylinder heads of the paint cylinders 22 and 23, respectively. It is.

Paint cylinders 22, 23 and hydraulic cylinder 2
4 and 25 are each provided with a connection port for injecting paint or hydraulic oil only on the bottom side of the cylinder, and are configured as a so-called single-acting type cylinder, and the piston rod 26 of the paint cylinder 22 and the hydraulic cylinder 24 facing each other are connected to each other. The piston rods 27 connect the rod heads to each other, and the piston rods 28 of the paint cylinder 23 and the piston rods 29 of the hydraulic cylinder 25 are also connected to each other.

Connected to the connection ports of the paint cylinders 22 and 23 are pipe lines 30 and 31, which are switchably connected to the paint pressure feed line 7 or 7' via an electromagnetic switching valve 20, respectively.

In addition, the connection ports of the hydraulic cylinders 24 and 25 are connected to a hydraulic pump 33 via an electromagnetic switching valve 32 that switches the flow path of the hydraulic oil, and are connected to a pressure pipe 34 or a hydraulic tank 35 that pressure-feeds the hydraulic oil. Conduits 37 and 38 are respectively connected which are switchably connected to the return conduit 36 for returning the hydraulic fluid.

The electromagnetic switching valves 20 and 32 are connected to the spool 4 by a solenoid 39 and a spring 40, respectively.
1 can be moved up and down to switch the flow paths for paint and hydraulic oil.

First, the high viscosity paint 1 in the paint tank 2 is pressurized by the plunger pump 3 while the solenoid 39 of the electromagnetic switching valve 20 inserted between the paint pressure feed pipes 7 and 7' is turned on. If you pressurize it,
The high viscosity paint 1 flows through the paint hose 5 and the paint pressure feed line 7 connected thereto into the flow path A shown in the block above the electromagnetic switching valve 20, and further flows into the flow path A shown in the block above the electromagnetic switching valve 20, and then through the connection on the bottom side of the cylinder of the paint cylinder 22. The paint cylinder 22 is fed through a line 30 connected to the mouth. At this time, the solenoid 39 of the electromagnetic switching valve 32 that switches the flow path of the hydraulic oil is also turned on, and therefore the paint cylinder 22 and its cylinder heads are connected to the connection port on the cylinder bottom side of the hydraulic cylinder 24, which is spaced apart from each other. Since the pipe 37 that has been supplied is connected to the return pipe 36 to the hydraulic tank 35 through the flow path a shown in the block above the electromagnetic switching valve 32, the high viscosity paint 1 is sent to the paint cylinder 22 as described above. When supplied, the piston 42 of the paint cylinder 22 is pushed up from the state shown by the chain line to the state shown by the solid line, and the high viscosity paint 1 is stored in the paint cylinder 22. In conjunction with this pushing up of the piston 42 of the paint cylinder 22, the piston 43 of the hydraulic cylinder 24 is also pushed up at the same time.
The hydraulic oil in the hydraulic cylinder 24 is returned to the hydraulic tank 35 through the conduit 37, the flow path a of the electromagnetic switching valve 32, and the return conduit 36.

On the other hand, at this time, the hydraulic oil in the hydraulic tank 35 is injected into the hydraulic cylinder 25 by the hydraulic pump 33 through the pressure pipe 34 - the flow path b of the electromagnetic switching valve 32 - the pipe 38. Push down the piston 44 and remove the piston rod 29.
Stretch. As a result, the piston rod 2
The piston rod 28 of the paint cylinder 23 connected to the paint cylinder 23 is contracted and its piston 45 is pushed down, and the high viscosity paint 1 stored in the paint cylinder 23 is transferred to the pipe line 31 - the flow path B of the electromagnetic switching valve 20.
The airless paint sprayer 10 is connected through the paint pressure feed pipe 7'.
is supplied under pressure.

That is, when the solenoids 39 and 39 of the electromagnetic switching valves 20 and 32 are turned on, the high viscosity paint 1 pumped from the plunger pump 3 flows through the paint hose 5 - the paint pressure feed line 7 - the electromagnetic switching valve 20. Line A - via line 30, the paint cylinder 22 is fed and stored therein.

At the same time, the high viscosity paint 1 that has already been force-fed from the plunger pump 3 and stored in the paint cylinder 23 is pushed out by the hydraulic cylinder 25, and is pushed out from the pipe line 31 to the flow path B of the electromagnetic switching valve 20 to the paint. It is supplied to the airless atomizer 10 through the pressure feed line 7'.

Then, at the same time as the extrusion of the high viscosity paint 1 stored in the paint cylinder 25 is completed, the solenoids 39, 39 of the electromagnetic switching valves 20 and 32
is turned off, the spools 41, 41 are moved upward by the elastic force of the springs 40, 40, and the electromagnetic switching valves 20, 32 are switched to the lower block in the figure.

As a result, the high viscosity paint 1 pumped from the plunger pump 3 is transferred from the paint hose 5 to the paint pressure feed line 7 to the flow path C of the electromagnetic switching valve 20 to the line 3.
1 to the paint cylinder 23.

At this time, the hydraulic oil injected into the hydraulic cylinder 25 is returned to the hydraulic tank 35 through the pipe 38, the flow path c of the electromagnetic switching valve 32, and the return pipe 36, so that the hydraulic oil injected into the hydraulic cylinder 25 is The high viscosity paint 1 fed into the paint cylinder 23 pushes up the piston 45 and is stored inside the paint cylinder 23. On the other hand, the hydraulic oil in the hydraulic tank 35 is injected into the hydraulic cylinder 24 by the hydraulic pump 33 through the pressure pipe 34 - the flow path d of the electromagnetic switching valve 32 - the pipe 37. The piston 43 is pushed down to extend its piston rod 27. As a result, the piston rod 27
The piston rod 26 of the paint cylinder 22 connected to the paint cylinder 22 is contracted, the piston 42 is pushed down, and the high viscosity paint 1 stored in the paint cylinder 22 is transferred from the pipe line 30 to the flow path D of the electromagnetic switching valve 20.
- Airless paint sprayer 1 through paint pressure pipe 7'
0 will be supplied under pressure.

As described above, according to the embodiment of the present invention, the high viscosity paint 1 pumped from the plunger pump 3 is
The high viscosity paint 1 stored in the paint cylinders 22 or 23 is automatically and alternately stored in the paint cylinders 22 or 23 interposed between the paint pressure feed pipes 7 and 7'. Paint pressure feed pipe 7'
It will be supplied to the airless paint sprayer 10 through.

In this case, the high viscosity paint 1 is supplied to the airless paint sprayer 10 through the paint pressure feed pipe 7'.
Since the pump is not directly pumped by the plunger pump 3 as in the past, but is pumped by the hydraulic cylinders 24 and 25 that can be pressurized to an extremely high pressure, a high discharge amount can be obtained. Compared to the conventional method, more airless paint sprayers 10 can be connected to one plunger pump 3, and paint can be uniformly discharged without pulsation.

Additionally, if the nozzle of the airless paint sprayer 10 becomes clogged, this may cause the paint cylinders 22, 23 to become clogged.
Or, since it appears as a change in the operating speed of each piston rod of the hydraulic cylinders 24, 25, clogging of the nozzle can be detected relatively easily and quickly.

In the above embodiment, two paint cylinders 22 and 23 are connected to one plunger pump 3 via an electromagnetic switching valve 20, and the on/off control of the electromagnetic switching valves 20 and 32 is performed. Although the method of alternately storing the high viscosity paint 1 in the paint cylinders 22 and 23 and continuously supplying the high viscosity paint 1 to the airless paint sprayer 10 has been described, the present invention is not limited to this. As shown in Figure 3,
A set of paint cylinders 2 between the paint pressure feed pipes 7 and 7'
2 and a hydraulic cylinder 24, first, with the paint discharge of the airless paint sprayer 10 stopped, high viscosity paint 1 is introduced into the paint cylinder 22 from the plunger pump 3 through the paint hose 5 and the paint pressure feed pipe 7. It is fed and stored once, and then the hydraulic cylinder 2
4, the high viscosity paint 1 stored in the paint cylinder 22 is supplied to the airless paint sprayer 10 through the paint pressure feed pipe 7', and is intermittently discharged from the airless paint sprayer 10. , the same effect as above can be obtained in this case as well.

As described above, according to the present invention, a paint cylinder is interposed in a paint pressure-feeding conduit for pumping high-viscosity paint, and the paint cylinder and its cylinder heads are spaced apart from each other, and the rod heads of the piston rods are connected to each other. Connected hydraulic cylinders are arranged, and the high viscosity paint that is pumped from the paint pressure pump is first fed into the paint cylinder and temporarily stored, and then hydraulic oil is injected into the hydraulic cylinder to move the piston rod. By extending the piston rod of the paint cylinder, the piston rod of the paint cylinder is contracted, and the high viscosity paint stored in the paint cylinder is supplied to the airless paint machine through the paint pressure feed pipe, so the high viscosity paint can be delivered without pulsation. It is possible to supply airless paint sprayers under high pressure, which eliminates uneven paint discharge due to pulsation, and at the same time allows the use of more airless paint sprayers than before with one paint pressure pump. This has the excellent effect of significantly reducing equipment costs, and also has the effect of relatively easily detecting clogging of the nozzle of an airless paint sprayer.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional method for supplying a high viscosity paint, and FIGS. 2 and 3 are system diagrams showing an example of a method for supplying a high viscosity paint according to the present invention. Explanation of symbols, 1... High viscosity paint, 3... Plunger pump (paint pressure feeding pump), 7, 7'... Paint pressure feeding pipeline, 10... Airless paint sprayer, 22, 2
3... Paint cylinder, 24, 25... Hydraulic cylinder, 26, 28... Piston rod of the paint cylinder, 27, 29... Piston rod of the hydraulic cylinder.

Claims (1)

[Claims] 1. In a method of supplying high viscosity paint to an airless paint sprayer by force-feeding the high-viscosity paint with a paint pressure-feeding pump, a paint cylinder is interposed in the paint pressure-feeding pipeline for force-feeding the high-viscosity paint, and the paint cylinder and A hydraulic cylinder is provided whose cylinder heads are separated from each other and which are connected to each other, and the rod heads of the piston rods are connected to each other, and the high viscosity paint that is pumped from the paint pressure pump is first fed into the paint cylinder and temporarily stored. Then, by injecting hydraulic oil into the hydraulic cylinder and extending its piston rod, the piston rod of the paint cylinder is contracted, and the high viscosity paint stored in the paint cylinder is transferred to the airless paint cylinder through the paint pressure feeding pipe. A method for supplying high viscosity paint, characterized by supplying it to a coating machine.