JP2728804B2 - Paint supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paint supply device including a color changing device, a paint pipe, a paint gear pump, and the like.

[0002]

2. Description of the Related Art FIG. 5 shows a general structure of a paint supply apparatus using a paint gear pump (20). In the figure,
Reference numeral 10 denotes a color change device, and a color change valve CVx, Y (for example, white) for X (for example, red) color is provided in the manifold 11.
A color change valve CVy for color, an air change valve CVa, and a cleaning liquid change valve CVw are attached.

[0003] A paint gear pump 20 is accommodated in a casing 21.
0 and the downstream side is connected to a supply destination (spray gun) 100 by a paint pipe 14. The casing 21 has a plurality of casing elements 21A,
21B and 21C (see FIG. 6).

[0004] The gear pump 20 has a higher quantitative accuracy than a so-called air operation type. Japanese Patent Application Laid-Open No. 57-165885,
JP-A-60-178381 is an example. Also,
The compressed air source 12 is connected to the air change valve CVa, and the paint cleaning liquid supply source 31 is connected to the cleaning liquid change valve CVw via a pipe 32.

In such a paint supply device, the color changing device 10
When the X color change valve CVx and the air change valve CVa are opened, the X color paint is sent to the gear pump 20 through the paint pipe 13. Here, if the drive shaft 22 is rotated, the X-color paint can be supplied to the spray gun 100 from the discharge unit 28 to the spray gun 100 through the paint pipe 14 in cooperation with the two gears 23 and 26 (the driven shaft 25).

Next, in order to switch to the Y color paint, both change valves CVx and CVa are closed and the cleaning liquid change valve CVw is opened. Then, the pressure P from the supply source 31
A paint cleaning liquid (for example, 1 to 5 kg / cm ² g) (for example, thinner) is injected into the manifold 11. That is, the paint supply system [11, 13, 20 (23, 26),
14], and the previously used X-color paint can be washed and wiped off. Reference numeral 30 in FIG. 5 indicates a cleaning system of the paint supply system. Thereafter, by opening the Y color change valve CVy and the air change valve CVa as before, the Y color paint can be supplied to the spray gun 100.

By the way, the above-mentioned washing step must be performed promptly and completely so that the paint (X color) used before does not remain. Here, conventionally, at the time of washing, the gear pump 20 is rotated at a higher speed than the rotation speed at the time of the normal paint supply operation,
In addition, a bypass pipe 34 and a bypass valve 33 are provided to allow a large amount of cleaning liquid to flow through the paint pipes 13 and 14 for quick cleaning.

On the other hand, in order to clean up the integrity, that is, the residual color, the side surfaces 23 of the gear pump 20, especially the gears 23 and 26, are removed.
The pre-color (X in the above case) paint adhered to S and 26S is also cleaned. For this purpose, the gear pump 2
Gear cleaning system 4 for injecting the cleaning liquid through the drive shaft 22
0 is provided. That is, as shown in FIG. 6, the injection flow path 41 (the branch fine hole 41) is provided in the drive shaft 22 of the gear pump 20.
a), the return flow path 43 into the driven shaft 25 (branch pore 43a)
And the two 41 and 43 are communicated with each other through a communication channel 42 in the casing 21. As shown in FIG. 5, pipes 45 and 47 having a cleaning valve 46 are connected to the injection channel 41. Further, a pipe 49 for discharging to the outside is connected to the return channel 43. The casing 21A
Are connected to the injection flow path 41 and the return flow path 43, respectively, and are interposed between the flow paths 41 and 43 and the pipes 47 and 49, respectively.

As shown in FIG. 6, the drive shaft 22 passes through a casing 21C (through hole 21H) and is connected to a motor shaft 29 (not shown) via a coupling. The penetrating portion is provided with a shaft seal portion including a packing receiver 37, a seal packing 38, and a case 27 as a packing presser. Further, the supply source of the cleaning liquid is a paint supply system (1) from the viewpoint of equipment economy and handling.
In general, the supply source 31 of the cleaning liquids (1, 13, 20, 14) is shared.

Thus, if the cleaning valve 46 is opened during the color change (X → Y), the paint cleaning liquid supplied from the supply source 31 through the pipes 45 and 47 causes the injection flow in the drive shaft 22 to flow. The pre-color paint adhered to the side surfaces 23S and 26S of the gears 23 and 26 through the path 41 and the branch pore 41a is wiped out, and is discharged to the outside through the branch pore 43a and the return passage 43. However, a part is discharged to the downstream paint pipe 14 through the teeth of the gears 23 and 26 of the gear pump 20 and the discharge section 28. As described above, the paint supply system (11, 13, 20, 14) is quickly cleaned while rotating the gear pump 20 at a higher speed than usual using the cleaning systems 30, 40, and the side surfaces 23S, The paint adhered to 26S etc. is also completely washed.

[0011]

By the way, even if such a high-speed and complete cleaning measure is taken, it is a modern technology which satisfies the practice of operation such that it does not make excess equipment and it is difficult to allow some residual color after switching. I cannot fulfill my request.

That is, the paint color after color change often contains a residual color exceeding the allowable range of quality (paint before switching), and in some cases, a residual color solidified component such as the last two times before. is there. Also, if the motor is overloaded,
There is also a problem that the drive shaft 22 itself cannot rotate due to seizure.

Further, such a problem arises in the paint supply system (1).
1,13,20,14) tend to occur more easily so as to take the most effective measures for achieving faster cleaning, that is, as the rotational speed of the gear pump 20 during the cleaning operation is further increased from the rotational speed during the paint supply operation. This is a factor that hinders high-speed color change.

Here, as proposed in the above publications, the paint supply apparatus employing the gear pump 20 is not widely used, while having the advantage of high-precision quantitative supply over the air operation type. The fact is that it is.

SUMMARY OF THE INVENTION An object of the present invention is to provide a paint supply apparatus capable of quickly cleaning a paint supply system and a gear side surface and performing color change without residual color.

[0016]

SUMMARY OF THE INVENTION According to the present invention, as a result of tests and studies using practical equipment, paint is easily solidified in a shaft seal portion of a drive shaft, and in some cases, a backflow into a gear pump is prevented. Based on the analysis that these factors have been one of the main causes of problems in the past, and based on the analysis that these factors were one of the main causes of The above purpose is achieved by removing.

That is, the present invention comprises a color changing device, a paint piping, and a paint gear pump housed in a casing, and supplies a paint cleaning liquid from the color changing device to the gear pump rotated at high speed between color changes. To wash the paint supply system, and to wash the side of the gear inside the gear pump while injecting the paint washing liquid through the injection passage in the drive shaft so that the washed liquid can be returned to the outside through the return passage in the driven shaft. In the coating material supply device formed in the above, an annular recess is provided in a packing receiver forming a shaft seal portion provided in a portion of the drive shaft penetrating the casing, and the annular recess and the injection flow path are connected to the drive shaft. A first communication passage formed therein, and the annular recess and the return flow passage are connected by a second communication passage penetrating the casing.

[0018]

According to the present invention, the side surface of the gear is washed while the paint washing liquid is injected from the injection passage in the drive shaft. At this time, the annular recess provided in the packing receiver forming the shaft seal portion has the first
Fresh paint cleaning liquid is supplied from the injection flow path through the communication path and returned to the return flow path through the second communication path. Therefore, the cleaning liquid pressure in the shaft seal portion (annular concave portion) is equal to the liquid pressure after cleaning the inside of the casing, so that the dirt cleaning liquid does not enter the drive shaft and the casing penetrating portion.
Of course, the liquid in the shaft seal portion is a fresh paint cleaning liquid and does not cause stagnation of the liquid.

Therefore, it is possible to completely prevent the paint from solidifying in the shaft seal portion and the shaft penetrating portion, and to carry out a complete color change quickly and smoothly.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the present paint supply device has a basic structure of a color changing device 10, a paint gear pump 20, a paint pipe 1
5, 14 and the like, and the shaft seal portion (37H) between the through hole 21H of the casing 21 (21C) and the drive shaft 22 is fresh. The paint cleaning liquid is positively circulated and circulated to eliminate the solidification phenomenon of the paint. Note that the color changing device 1
The same reference numerals as those in the conventional example, such as 0, the gear pump 20, and the like, are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 1 to FIG. 4, a packing receiver (made of metal) 37 that forms a shaft seal together with a case 27 as a packing presser and a packing (made of Teflon) 38 is provided.
An annular recess 37H is provided. On the other hand, a first communication passage 51 communicating with the injection flow path 41 is provided in the drive shaft 22. As shown in FIGS. 2 and 3, the first communication passage 51 is a passage 51 </ b> C extending in the axial direction directly connected to the injection flow passage 41.
And two communication passages 51a and 51b extending in the radial direction. However, the communication path may be any one of 51a and 51b.

That is, the first communication passage 51 is connected to the drive shaft 22.
The inside of the injection channel 41 communicates with the shaft seal portion (annular concave portion 37H), and has a role to positively inject fresh paint cleaning liquid in the injection channel 41 into the shaft seal portion (37H).
In this embodiment, the first communication passage 51 (51c) is formed integrally with the injection flow passage 41, that is, the shaft diameter is the same, and the shaft sealing portion ( The cleaning liquid pressure in 37H) is formed to be slightly higher. Therefore, even if fresh paint washing liquid in the shaft seal portion (37H) flows through the through hole 21H and into the casing 21, the paint containing the paint from the inside of the casing 21 to the shaft seal portion (37H) side becomes dirty. There is no influx of cleaning liquid.

On the other hand, the second communication passage 52 is means for directly discharging the cleaning liquid in the shaft seal portion (37H) to the return flow passage 43 formed in the driven shaft 25.
It is formed from a pipe passing through 1C.

Here, the first and second communication flow paths 51, 5
2 is understood to form a forced circulation means for forcibly circulating fresh paint cleaning liquid to the shaft seal portion (37H).

In this embodiment, when a fresh paint cleaning liquid is injected from the injection channel 41 (41U) in the drive shaft 22,
The liquid that has flowed into the casing 21 from the branch pore 41a cleans the gear side surfaces 23S and 26S, and then cleans the branch pore 43a.
Through the return passage 43 (43D). That is, the gear side surfaces 23S and 26S can be cleaned.

At this time, fresh paint washing liquid is forcibly circulated through the first and second communication passages 51 and 52 in the shaft seal portion (37H). Therefore, the shaft seal portion (37,
37H, 38), the cleaning liquid is always kept clean so that the dirty cleaning liquid does not enter and there is no idea that stagnation and solidification of the paint will occur. Further, the dirty cleaning liquid does not enter the through hole 21H of the casing 21C.

Thus, according to this embodiment, the drive shaft 2
The first communication path 51 (51a, 51b, 51c) connecting the injection flow path 41 in the second 2 and the shaft seal portion (37H), and connects the shaft seal portion (37H) with the return flow path 43 in the driven shaft 25. Since the second communication path 52 is provided and the fresh paint cleaning liquid is forcibly circulated in the shaft seal portion (37H), the dirty cleaning liquid containing the washed paint in the casing 21 can pass through the penetrating portion ( 22, 22H), the conventional problem of residual color due to stagnation in the shaft seal portions (37, 38) at the dead end and backflow of the solidified paint into the paint supply system is eliminated, and complete color change can be guaranteed.

Further, although a fresh paint cleaning liquid flows into the casing 21 from the shaft seal portion (37H), a dirty cleaning liquid containing a paint component from the casing 21 passes through the penetrating portions (22, 21H) to seal the shaft. Parts 37H, 37, 3
8 so as not to penetrate into the through portion (2
2, 21H) does not contain the solidified paint, particularly the aluminum fine particles of the metallic paint, so that smooth rotation of the drive shaft 22 is ensured, and shaft damage due to galling or the like can be completely prevented.

[0029]

According to the present invention, the first and second communication passages are provided for communicating the injection flow passage, the return flow passage, and the annular recess provided in the packing receiver forming the shaft seal portion, and the shaft seal portion ( Since the fresh paint cleaning liquid is forcibly circulated in the annular concave portion), overload of the motor, damage to the drive shaft, sticking of the seal packing of the shaft seal portion, and the like can be eliminated, and smooth and quick color change can be performed.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of the present invention.

FIG. 2 is also an enlarged sectional view of a main part.

3 is a vertical sectional view based on the line AA of FIG. 2;

FIG. 4 is an external perspective view of a packing receiver and a packing.

FIG. 5 is an overall configuration diagram of a conventional paint supply device.

FIG. 6 is a side sectional view of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Color changing device 11 Manifold 12 Compressed air source 13 Paint pipe 14 Paint pipe 20 Paint gear pump 21 (21A, 21B, 21C) Casing 21H Through hole (penetrating part) 22 Drive shaft (penetrating part) 23 Drive gear 23S Gear side face 25 Driven shaft 26 driven gear 26S gear side surface 27 case (shaft seal portion) 28 discharge portion 29 motor shaft 30 paint supply system cleaning system 31 cleaning liquid supply source 32 pipe 33 bypass valve 34 bypass pipe 37 packing receiver (shaft seal section) 37H annular Concave part (shaft seal part) 38 Packing (shaft seal part) 40 Gear cleaning system 41 Injection flow path 41U flow path 41a Branch fine hole 42 Communication flow path 43 Return flow path 43a Branch fine pore 43D flow path 45 Piping 46 Cleaning valve 47 Piping 49 Piping 50 Forced circulation means 51 (51a, 51b) , 51c) First communication path 52 Second communication path 100 Supply destination (spray gun)

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-326958 (JP, A) JP-A-4-65157 (JP, U) JP-A-2-81656 (JP, U) JP-A-4-86 121486 (JP, U)

Claims (1)

(57) [Claims] 1. A paint supply system comprising a color changing device, a paint pipe, and a paint gear pump housed in a casing, and supplying a paint cleaning liquid from the color changing device to the gear pump rotated at a high speed during the color change. It is formed so that the system can be washed, and the side of the gear inside the gear pump can be washed while the paint washing liquid is injected through the injection passage in the drive shaft, and the washed liquid is returned to the outside through the return passage in the driven shaft. In the paint supply device, an annular recess is provided in a packing receiver that forms a shaft seal portion provided in a portion of the drive shaft that penetrates the casing, and the annular recess and the injection channel are formed in the drive shaft. A paint supply device, wherein the paint supply device communicates with a first communication passage, and the annular concave portion and the return flow passage communicate with each other through a second communication passage penetrating the casing.