JPH0798229B2 - Method and apparatus for applying a lubricant to a molded object - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for uniformly applying a small amount of lubricant to the molding surface of a molded object such as a can lid.

[0002]

2. Description of the Related Art Conventionally, when a can lid with a tab is manufactured, a rivet for fixing the tab to the center is formed by pressing, so that wax or palm oil is applied as a lubricant before the forming. Conventionally, the lubricant is applied to the sheet or coil before blank punching by spraying or roll coating.

[0003]

[Problems to be Solved by the Invention] In the case of press molding,
It is necessary to apply a lubricant to the molding surface for smooth molding, but in the case of a can lid, the lubricant is not only an impurity for the contents of the can, but also when printing on the lid surface after molding. Since it causes inconveniences such as difficulty in attaching the ink, it is desirable to apply the ink only to a necessary place as much as possible. However, since the conventional lubricant application method is performed by spraying or roll coating as described above, it is not possible to apply it only to a necessary portion, and it is applied to the entire surface of the blank or coil, and it is thin and uniform. There is a problem in that it is difficult to apply and it is not possible to satisfy the above demand.

The present invention is intended to solve the above-mentioned drawbacks of the prior art, and it is possible to apply a lubricant thinly and uniformly to only a required portion of the surface of the object to be molded. It is an object to provide a method and an apparatus thereof.

[0005]

In order to solve the above problems, as a result of various studies, the present inventor has found that when a lubricant is intermittently dropped into an air pipe which is horizontally long, The present invention has been achieved by finding that a continuous and uniform thin flow is obtained. That is, the method for applying a lubricant to a molded article of the present invention is to drop a lubricant into an air pipe in which an air flow is formed, and to apply the lubricant to the air flow in a horizontal long horizontal pipe portion of the air pipe. This can be solved by adopting a technical means characterized in that a continuous and uniform flow is sprayed onto the molding surface of the molding target.

An apparatus for achieving the above method is also
Lubricant metering device that discharges the lubricant quantitatively, the upstream end is connected to the air supply source, and the downstream end is connected to the nozzle that applies the lubricant to the molding surface of the molding target. connecting an air pipe, and a horizontal pipe portion of the air pipe and the discharge side of the lubricant dispensing device having a horizontal pipe portion of the
The lubricant dripping pipe, and
The feature is that the lubricant is dropped from the lubricant dropping pipe .

[0007]

[Operation] When a fixed amount of lubricant is intermittently dropped on the upstream side of the horizontal pipe portion of the air pipe, the lubricant dropped on the air pipe becomes a continuous and uniform flow of air in the horizontal and long horizontal pipe portion. . Therefore, when this is sprayed on the required parts of the molding surface of the object to be molded by opening and closing the solenoid valve, the lubricant can be applied thinly and uniformly only to the necessary parts.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 schematically shows an embodiment of the lubricant applying device of the present invention. In the figure, 1 is a lubricant dispenser,
In the present embodiment, a constant-quantity discharge device whose discharge amount can be freely adjusted by a ratchet knob is adopted, and its driving air is supplied from an air supply source 3 via a solenoid valve 2. Reference numeral 5 denotes a lubricant tank, which communicates with the suction port 7 of the lubricant constant amount discharger 1 from the lubricant tank via a check valve 6 by a lubricant supply pipe 8. The discharge port 9 of the lubricant constant quantity discharge device is connected to the upstream side of a horizontal pipe portion 16 of an air pipe 15 described later by a lubricant dropping pipe 11 via a check valve 10. The upstream end of the air pipe 15 is connected to the same air supply source 3 as the air supply source for supplying the drive air to the lubricant dispenser via a regulator 17. Reference numeral 18 is a solenoid valve, and a nozzle 20 for spraying a lubricant is provided at the outflow port thereof. The lubricant applying device of the present embodiment is configured as described above, and is disposed above the conveyor 22 that conveys the can lid shell 21 to the rivet forming device in the can lid forming process, and the can lid is conveyed by the conveyor. A lubricant is applied to the center of the panel of the shell 21.

The lubricant is applied to the can lid shell by the above apparatus as follows. The air supplied from the air supply source 3 through the air filter is controlled to a constant pressure by the regulator 17 and supplied to the air pipe 15. Further, the solenoid valve 2 is repeatedly turned on and off at an appropriate timing so that air is supplied from the air supply source 3 to the lubricant constant amount discharger 1, and the lubricant constant amount discharger 1 is intermittently driven to perform lubrication. The lubricant is sucked from the agent tank 5 and discharged from the discharge port 9, and the fixed amount of lubricant is intermittently dropped through the check valve 10 to the upstream side of the horizontal pipe portion 16 of the air pipe 15. The lubricant dropped onto the air pipe 15 becomes a continuous and uniform flow of air in the horizontal and long horizontal pipe portion 16. The can lid shell 21 conveyed by the conveyor 22 is detected by a sensor (not shown), and the solenoid valve 18 is placed at a timing when the can lid shell 21 is directly below the nozzle 20.
Open and spray the lubricant from the nozzle 20 to the center of the can lid. As a result, the lubricant is thinly and uniformly applied to the central portion of the can lid shell. The amount of lubricant applied to the can lid shell can be adjusted by adjusting the discharge amount from the lubricant constant amount discharge device 1 each time, adjusting the number of operations of the solenoid valve 2, that is, the number of drops, or both. Either adjustment or simultaneous adjustment is possible.

In the case of rivet molding of a can lid shell, the amount of lubricant applied to the rivet molding part is empirically 0.05 mg to 0.1 mg.
This is sufficient, and the following experiment was carried out in the above apparatus in order to obtain a coating amount in that range. Horizontal piping section 1
6 with a length of 1 meter, air pressure of 0.
For every 20 can lid shells that pass 5 kgf / cm ² and the number of discharges from the lubricant constant amount discharger 1 at a speed of 550 pieces per minute,
An experiment was conducted in which the lubricant was applied to all the can lid shells 21 passing below the nozzle so that the lubricant was discharged once every 30 and 40 sheets. As a result, in each case, by adjusting the discharge amount of the lubricant constant amount discharge device 1 within the range of 7 mg to 120 mg, the amount of adhesion to the central portion of the can lid shell can be freely adjusted from 0.02 mg to 0.8 mg. It was possible to adjust to a uniform value and to apply it uniformly. Further, when the length of the horizontal pipe portion 16 was set to 20 cm, a sufficient fine stream of the lubricant could not be obtained, and the coating amount in the desired range could not be obtained. Therefore, according to this example, it was found that the length of the horizontal pipe portion of the air pipe is 50 cm or more, preferably in the range of 1 to 2 m. Further, in the air pipe, the horizontal pipe portion only needs to be horizontal, and similar results were obtained even if the air pipe was bent or spiraled in a plane. However, when the air pipe was inclined, a continuous uniform flow of the lubricant could not be obtained even if the air pipe was long. From the above experimental examples, it was confirmed that the lubricant application method of the present invention is very effective for applying the lubricant to the can lid rivet portion in a minute amount.

[0011]

As is apparent from the above description, according to the present invention, it is possible to apply the lubricant thinly and evenly and reliably only to the required parts of the molding surface of the object to be molded. The adverse effect can be eliminated. Moreover, the device is simple and can be easily applied to a conventional molding line.

[Brief description of drawings]

FIG. 1 is a schematic diagram of piping of a lubricant applying device according to an embodiment of the present invention.

[Explanation of symbols]

1 Lubricant Dispenser 2, 18 Solenoid valve 11 Lubricant dripping pipe 15 Air pipe 16 Horizontal pipe portion 20 Nozzle 21 Can lid shell

Claims (2)

[Claims] 1. A lubricant is dropped into an air pipe in which an air flow is formed, and the lubricant is made into a continuous and uniform flow by the air flow in a horizontal and long horizontal pipe portion of the air pipe to be molded. A method for applying a lubricant to a molded article, which comprises spraying the molded surface of the article. 2. A lubricant metering device for metering a quantity of a lubricant, an upstream end connected to an air supply source, and a downstream end a nozzle for applying a lubricant to a molding surface of a molding target. An air pipe having a connected horizontal pipe portion of a predetermined length ,
A lubricant drip pipe connecting the discharge side of the lubricant constant amount dispenser and a horizontal pipe portion of the air pipe,
Lubricant should be dripped into the pipe from the lubricant drip pipe.
An apparatus for applying a lubricant to an object to be molded, characterized in that