JPH0356103B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a spray device for painting the inner surface of a can, particularly a three-nozzle spray device provided with nozzles for painting the crevasse between the can body and the can end plate. Regarding.

(Prior art) In the can making process, the inner surfaces of cans are painted by holding empty cans that fall from a chute in an overturned manner into individual pockets of a rotating turret that rotates intermittently on a vertical surface. When it rotates and reaches the position where the injection nozzle is located, the rotation of the rotating turret momentarily stops, and during that time, the two spray guns for the can body and can end plate (hereinafter referred to as the end) rotate at high speed. This is done by sticking out like a spear into an empty can and spraying paint on it.

Conventionally, as a spray device for this purpose, a spray device as shown in FIG. 3, which is called a lance type spray device, is known. In this spray device, a body gun 15 for painting the inner surface of the can body and an end gun 16 for painting the inner surface of the end are combined together and fixed on a movable table 17. connected to the paint supply. A body nozzle 20 is provided at the tip of the body gun 15 and sprays paint at a certain angle to the axis of the body nozzle 20.
An end nozzle 21 for spraying paint in the axial direction is provided at the tip. The movable trolley 17 is driven reciprocally toward the rotary turret 23 in which the cans are held.
It is located on 2.

When painting the inside of a can, the rotary turret 23, which holds the can c and revolves around it, stops instantaneously when it reaches the position where the spray device is installed. In the meantime, the movable cart 17 supporting the body gun and the end gun moves on the machine base 22, and as shown by the phantom line in FIG.
The nozzles 20 and 21 at the tip of the end gun 16 are gradually inserted into the rotating can c held in the pocket of the turret, and during the entry process, paint is ejected from each nozzle to paint the inner surface of the can. It's summery.

Therefore, in this coating method, when painting the crevasses that occur in the seams of the can body and end of a three-piece can, paint applied excessively on the end may flow into the crevasse due to centrifugal force. A method is used in which excess paint applied to the can body is allowed to drip naturally at an upright position during transportation.

For this reason, the coating of crevasses is greatly influenced not only by spray conditions, but also by conveyance conditions and drying conditions. Otherwise, there were problems such as blistering caused by caramel-like foaming of excess paint.

Furthermore, in neck-in cans in which the diameter of the can body is reduced near the seam, paint tends to accumulate in the neck shoulder where the diameter is reduced, and it is difficult for the paint to naturally flow down into the crevasse.

In order to reliably paint the crevasse without causing the above problems, it is desirable to spray the can body, end, and crevasse with separate nozzles. However, in the conventional device called the lance type, the number of guns that can be inserted into the can body is limited to two, one for the end and one for the body, and three guns were considered impossible.

In contrast, the present inventors first provided a branching path in the paint flow path of the nozzle tip body of the end gun, provided an end nozzle at the tip of the flow path, and provided a crevasse nozzle at the tip of the branched path. We proposed a spray device that not only sprays the ends but also directly sprays and paints the crevasses using a special nozzle.
No. 59-22831). Although this device has two guns inserted into the can body, one for the end and one for the body, it has the great effect of improving the coating of the crevasse area, greatly reducing the defects of conventional devices, and saving the amount of paint used. Obtained.

(Problem to be solved by the invention) However, when paint is sprayed from a crevasse nozzle, the paint becomes mist droplets and is distributed with a wide spread, making it impossible to concentrate on one specific point. When the production line is run at a high speed, such as for cans, the time required for drying after painting is short, resulting in the problem that the paint cannot flow down sufficiently into the crevices. Furthermore, if the amount of spray is increased in order to increase the amount of flow, the same problems as those of conventional devices will occur.

The present invention was devised to solve the above problems, and it is possible to reliably paint crevasses even at high production line speeds.
It is an object of the present invention to provide a spray device that can save paint and can be easily applied to conventional spray devices.

(Means for Solving the Problems) The present invention solves the above problems by combining a body gun having a body nozzle at its tip and an end gun having an end nozzle at its tip, fixed on a movable table, and the movable table movable. By doing so, the body nozzle and the end nozzle enter the can together, and spray paint from the body nozzle to the inner surface of the can body and from the end nozzle to the inner surface of the can plate, thereby painting the inner surface of the can. Attaching a nozzle tip body having a paint flow path to the end nozzle and a branching path from the paint flow path to the tip of the end gun, and attaching the end nozzle to the tip of the paint flow path,
The problem has been solved by a structure characterized in that a crevasse stream nozzle is provided at the tip of the branching path to directly inject paint into the crevasse portion of the can.

(Function) Since the crevasse nozzle provided in the end gun is configured as a stream nozzle, the paint sprayed from the nozzle becomes a jet stream and can be sprayed in a concentrated manner at one point. Therefore, by directing this paint stream toward the crevasse, paint can be applied directly to the crevasse, and the paint sprayed around the crevasse can flow into the crevasse, as in the case of spraying in the form of mist droplets. Since it does not require much time, even if the production line speed is high, it not only ensures reliable coating, but also eliminates wasted coating around crevasses, saving paint usage.

In addition, since the crevasse nozzle is provided by forming a branch path in the nozzle tip body attached to the end gun, there is no need to provide a separate crevasse gun.
It can be constructed compactly, can be freely moved in and out of the can, and can be easily applied to conventional equipment.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic diagram of the spray gun section of the three-spray device of this embodiment, and only the vicinity of the nozzle section, which is different from the conventional rank type spray device shown in FIG. It is shown enlarged to show that it has penetrated inside.

In the figure, reference numeral 2 denotes a body gun, which has a body nozzle 10 at its tip that sprays paint at a constant angle to its axis to paint the inner surface of the can body.
3 is an end gun, and a nozzle tip body 3' is attached to the tip thereof. A cross section of one embodiment of the nozzle tip body 3' is shown in FIG. As shown in the figure, the nozzle tip body 3' is
A branch path 11 is formed in the middle of the paint flow path 7, and an end nozzle 8 is provided at the tip of the paint flow path 7 to spray paint in the axial direction of the end gun to paint the inner surface of the end, as in the conventional case. A crevasse stream nozzle 9 is provided at the tip of the branch path 11 at a constant angle with the end nozzle and sprays paint toward the crevasse of the can to paint the crevasse. This nozzle 9 is a stream injection nozzle that has a minute injection hole with a diameter of about 0.1 mm at its tip and aims directly at the crevasse portion 5.

And the body gun 2 and the end gun 3
is fixedly supported on a moving table (not shown), and its base end is connected to a paint supply source, similar to the conventional lance type spray device shown in FIG.

The apparatus of this embodiment is constructed as described above, and the body gun 2 and the end nozzle 3 are inserted into a rotating can, and the body nozzle 10 and the end nozzle 8 are inserted into the can.
By spraying the paint from the crevasse stream nozzle 9, the paint is directly sprayed toward the inner surface of the can, the end inner surface, and the crevasse, and the inner surface of the can is uniformly coated.

In particular, since the crevasse nozzle is constituted by a stream nozzle, the paint is directly applied to the crevasse, and the amount of paint applied to the shoulder portion 4 and end 6 around the crevasse is much smaller than in the past.

(Effects) Since the present invention has the above-mentioned configuration, the crevasse portion is directly coated with the paint jet, so even if the line takes a short time to reach the drying oven after painting, problems such as paint omission will not occur. In addition, there is no need to spray excessive amounts of paint onto the can body or end portions, resulting in significant effects such as saving paint and preventing the occurrence of bridging and blisters.

[Brief explanation of drawings]

The drawings show an embodiment of the three-nozzle spray device according to the present invention, FIG. 1 is a schematic side view thereof, FIG. 2 is a sectional view of one embodiment of the nozzle tip body, and FIG. 3 is a conventional lance type spray device. FIG. 2 is a side view of the device. 1: Can body, 2: Body gun, 3: End gun,
3': Nozzle tip body, 5: Crevasse, 7:
Paint flow path, 8: End nozzle, 9: Dream nozzle for crevasse, 10: Body nozzle, 11: Branch path.

Claims (1)

[Claims] 1. A body gun with a body nozzle at the tip,
An end gun having an end nozzle at the tip is combined and fixed on a movable table, and as the movable table moves, the body nozzle and the end nozzle enter the can together, and the can is removed from the body nozzle. In a spray device for painting the inner surface of a can by spraying paint from the end nozzle onto the inner surface of the can end plate, the end gun includes a paint flow path to the end nozzle and a branch path branching from the paint flow path. A three-nozzle spray device, characterized in that a nozzle tip body having a nozzle tip body is attached thereto, an end nozzle is provided at the tip of the paint flow path, and a crevasse stream nozzle for spraying paint directly into the crevasse of a can is provided at the tip of the branch path.