JPH02185444A - Printing device for columnar object - Google Patents

Abstract

PURPOSE:To ensure that a columnar object is printed at low cost without requiring a large space for complicated printing work by supporting the first and second moving shafts in an axial direction allowing these shafts to rotate at the central axis of a columnar object, as an axis, which is placed at a printing position, and controlling the output of dots from a printing head in response to a position signal from the two moving shafts in an axial direction and a position signal from a rotating shaft. CONSTITUTION:Two printing heads are provided; one of these is a printing head 1 for lateral writing and the other is a printing head 2 for vertical writing. Each one of these is supported, in parallel with the center axis of a cylinder 3, on moving shafts 4, 4' caused to move simultaneously in an axial direction. These two moving shafts in an axial direction are installed at an almost opposed position with respect to the center shaft, and are fixed to a single rotating shaft 5 which rotates at the center shaft as a pivot. The ejection in dots of ink or paint ejected from the individual nozzles of the printing head is controlled in response to a signal corresponding to the position of the printing head caused to move on two moving shafts in an axial direction and a position signal from the rotating shaft 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for printing on the surface of a cylindrical object, particularly a cylinder, a drum can, etc.

[Conventional technology]

LP gas cylinders are required by law to undergo pressure tests and other inspections at regular intervals. Normally, cylinders are painted entirely gray, with legal letters printed in red, as well as the cylinder owner's address, store name, etc. During inspection, it has been decided that these coatings will be removed, and after the inspection, the pages will be IH and legal characters will be printed on them. In addition, it is necessary to print the owned pitch name, address, etc. again. There are many types of cylinders, such as those for 10.20130.50kg, and owners may have as many as 1000 types of printing. Even in cylinders for hydrogen, oxygen, and nitrogen,
There are many types of printing required. There is also a large demand for printing on the surface of drum cans.

Conventionally, printing on the surfaces of these cylindrical objects has relied on manual labor. That is, a stencil in which predetermined characters are cut out from a steel or plastic plate having the same curvature as the surface of the cylindrical object is applied to the cylindrical object, and paint is sprayed or applied.

[Problem that the invention seeks to solve]

Conventional manual processing has problems with the working environment and takes time.

When printing, the stencil tends to lift off the surface, making the characters in that area blurry and unclear. This phenomenon is particularly likely to occur because the surface to be printed is cylindrical. Furthermore, in order to cut out hollow characters (for example, ``times'') or complex characters using a stencil, a connecting part is required, so the characters cannot be expressed accurately.Additionally, stencils for each type of printed content are required.

As for the printing content on LP gas cylinders, legal characters are printed in red in 3 to 4 lines in the circumferential direction of the cylinder. Ordinary characters such as addresses are often printed in white in vertical writing in 3 to 4 lines, and must be printed on the opposite side of the circumference from legal characters.

Therefore, an object of the present invention is to provide a device that automates the above-mentioned complicated printing work, which does not require a large space and can be manufactured at low cost.

[Means to solve problems]

The present invention is an apparatus for printing on the surface of a cylindrical object, in which a dot matrix print head that prints dots of ink or paint and expresses characters and symbols by a collection of dots is supported toward the surface of the cylindrical object. A first axial movement axis for moving the cylindrical object in the axial direction and a central axis of the cylindrical object placed at the printing position are located at a position substantially opposite to the above movement axis, and a similar dot matrix print head is used. a second axial movement axis that similarly supports and moves; a rotation axis that supports the first and second axial movement axes and rotates about the central axis of the cylindrical object placed at the printing position; This printing device has a control section that controls the output of dots from a print head in accordance with position signals from two axial movement axes and a position signal from a rotation axis.

In the present invention, a cylindrical object does not necessarily have to be cylindrical in its entirety, but refers to an object in which the part to be printed is cylindrical, such as cylinders, especially LP gas cylinders, oxygen cylinders, hydrogen cylinders, and nitrogen cylinders. , it is a drum can.

As the dot matrix print head itself used in the present invention, a known one can be used.

Preferably, the print head comprises several, for example 24, non-contact dot marking guns arranged in a straight line, each capable of ejecting pressurized ink or paint in the form of small droplets to mark dots on the surface to be marked. is preferred. Such individual marking guns themselves may be those described in, for example, Japanese Utility Model Publication No. 62-29094, filed by the present applicant, and a print head composed of a marking gun may be, for example, the one described in Japanese Utility Model Publication No. 1982-29094, filed by the present applicant. Those described in Japanese Patent No.-145734 can be used. by this,
Problems with stencil printing methods such as unclear characters, managing and storing stencils, expressing complex characters, and difficulty changing printed content are resolved.

The present invention will be described below with reference to the drawings.

FIG. 1 is a sketch showing an example of the device of the present invention, which has two print heads, one for horizontal writing (writing along the circumference at right angles to the central axis of a cylindrical object). The other is a printing head 1 for vertical writing (writing parallel to the central axis of a cylindrical object), and each print head is connected to the central axis of the cylinder 3 (hereinafter simply referred to as the central axis). It is supported on an axial displacement shaft 4.4' for movement parallel to (sometimes), simultaneously or preferably independently. These two axial movement axes are located substantially opposite to each other with respect to the central axis.

The above two axial movement axes are fixed to one pivot shaft 5 that pivots around the central axis.

A maximum angle of rotation of 90 to 120 degrees is usually sufficient.

Since the two axial movement axes are thus provided and these are fixed to one rotation axis, the mechanical structure is simple and the control is also simple as will be described later.

Control of the dot-like jetting of ink or paint from the individual nozzles of the print head is controlled by signals corresponding to the position of the print head as it is moved on the two axial movement axes, such as encoder pulse signals detected from the motor shaft. , and a position signal of the rotation axis, such as an encoder pulse signal, the control unit opens a predetermined nozzle.

The cylinder to be printed is fed from the left side of the figure and transported by a conveyor to the position of the rotation axis 5, where it is placed in the clamp 1.
0 and fixed. When printing is completed, the cylinder is carried to the right in the figure by a conveyor, and at the same time another cylinder is carried to the position of the rotation axis 5.

FIG. 2 shows the flow of control signals in the device of the present invention.

In the figure, the pulse signal from the encoder of the moving axis or rotation goes to the control device. Then the control device is the upper CP
Reads the print data from the floppy disk according to instructions from the LI or keyboard, and passes the print dot signal to the print driver. The print driver includes 24 drivers corresponding to 16 or 24 dot matrices in the vertical and horizontal directions to constitute, for example, kanji characters and symbols, and converts each dot signal into a pulse signal for driving the print head (for example, 24V, I
Convert to OA>.

It is possible to have two rows of control devices and print drivers corresponding to the two print heads, but in order to reduce costs, one row is used, and the driver pulses from the print driver are sent to two prints according to instructions from the control device. It is preferable that the head is provided with a distributor for distributing it appropriately.

The operating time of the printing drive itself is extremely short.

Legal characters and ordinary characters, such as addresses and store names, are entered from the keyboard and recorded on a floppy disk with a registration number attached as print data.

The configuration of the control unit described above is an example and is not limited thereto.

Let us take as an example the case where legal characters and ordinary characters are printed on an LP gas cylinder. LP gas cylinders are printed in an upright position. The first print head sprays dots of red paint to write legal characters horizontally (circumferentially), and 24 nozzles are arranged vertically in a line on the front surface of the print head. The second print head normally sprays dots of white paint to write characters vertically, and has 24 nozzles lined up horizontally on the front surface of the print head.

Legal characters are printed by rotating the rotation axis in forward and reverse directions, and line breaks are performed by stepwise movement of the movement axis that supports the first print head. That is, printing is performed by repeating forward rotation → line feed → reverse rotation → line feed → forward rotation.

Printing of ordinary characters is performed when the moving shaft supporting the second print head is lowered and raised, and horizontal movement at the time of line feed is performed by the rotating shaft. In other words, it repeats descending → line feed → rising → line feed → descending. 16 or 24 dot signals corresponding to characters and symbols are sent from the control device to the print driver in the order corresponding to the normal rotation or reverse rotation of the rotation axis, and the upward or downward movement of the moving axis.

The dot signal from the control device to the print driver outputs normal character content when the moving axis is moved, and legal character content when the rotation axis is moving. The distributor outputs the dot signal received from the control device to the first head when the vertical axis is moving, and to the second head when the rotating axis is moving. By controlling two types of printing contents in accordance with the movement of the machine in this way, the structure of the machine is simplified, and there is only one control system, resulting in an inexpensive device.

Although the apparatus described above has two print heads, this is the basic configuration, and three or more print heads can be provided as desired.

However, recent print heads (for example, Japanese Utility Model No. 58145
Since the printer (No. 734) operates at high speed, two print heads are usually sufficient.

As described above, according to the present invention, there has been provided a printing device that automatically prints on a cylindrical object and that can achieve complicated printing contents with a simple and inexpensive device configuration.

[Brief explanation of the drawing]

FIG. 1 is a sketch showing an example of the device of the present invention;
The figure is a diagram showing the flow of control signals of the device. (Explanation of symbols of main parts) 1.2: Print head 3: Cylinder 4.4': Axial movement axis 5: Swivel axis Applicant: Marktec Co., Ltd.

Claims (1)

[Claims] 1. In an apparatus for printing on the surface of a cylindrical object, a dot matrix print head that prints ink or paint in dots and expresses characters and symbols by a collection of dots is used to print on the surface of a cylindrical object. A first axial movement axis for supporting the cylindrical object in the axial direction, and a central axis of the cylindrical object placed at the printing position, which is located at a position substantially opposite to the above-mentioned movement axis, and similar dots. a second axial movement axis that similarly supports and moves the matrix print head; a rotation axis that supports the first and second axial movement axes and rotates about the central axis of the cylindrical object placed at the printing position; and a control section that controls the output of dots from the print head in accordance with the position signals from the two axial movement axes and the position signal of the rotation axis. 2. Each dot matrix print head has a plurality of linearly arranged ink or paint injection nozzles, and in printing supported by the first axial movement axis, the row of the injection nozzles is aligned with the central axis of the cylindrical object. 2. The printing device according to claim 1, wherein the row of jet nozzles is arranged perpendicular to the center axis of the cylindrical object in a print head which is arranged parallel to the cylindrical object and supported by the second axial movement axis.