JPS5814315B2 - Jiku Ukesouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bearing device for a printing device that supports a movable body to which a print head is attached movably about a shaft.

For example, an ink jet recording device that has become widely used these days has a movable body equipped with an emitter having an ink jet mechanism, and this movable body is movably supported on a horizontally installed shaft. It is configured to move in the horizontal direction, that is, in the digit direction of the characters and numbers to be printed, guided by a shaft by a moving mechanism.

In this case, in order to move the movable body smoothly, a bearing is provided at the fitting portion of the movable body with the shaft.

Since the shaft and the bearing are in surface contact with each other, this bearing undergoes changes due to wear due to friction during operation and expansion and contraction due to temperature changes.

This causes looseness or close contact between the shaft and the bearing, making it difficult for the moving body to move linearly and smoothly in a stable state.

In addition, there is also a loss of power in the driving force of the moving mechanism that moves the moving body.

In particular, with this printing device, if the linear and smooth movement of the moving object is disturbed, the ejected ink will be disturbed, making it impossible to print well, and the printing speed will be delayed, which can have a serious impact on the function. Become.

The present invention has been made in view of the above-mentioned circumstances, and by imparting a magnetic force to the shaft and the bearing of the moving body to which the print head is attached, and applying magnetic repulsion between the bearing and the shaft, the moving body is moved relative to the shaft. A printing device that not only eliminates the above-mentioned drawbacks but also prevents wear between the bearing and shaft, allowing for faster, more stable, linear and smooth movement. The present invention provides a bearing device.

An embodiment in which the present invention is applied to an ink jet recording apparatus will be described below with reference to the drawings.

FIG. 1 shows the above-mentioned ink jet printing device. In the figure, 1 is a base provided with a pulse motor of a moving mechanism, etc., and 2 is a pulley 3 provided on this base 1.・A wire 5 is suspended on the drive wheel 4 and is wound around the drive wheel 4 driven by a pulse motor to pull the moving body. The wire 5 is provided horizontally on the upper part of the base 1 and consists of a permanent magnet that is a component of the bearing device. A horizontal shaft 6 is a movable body movably supported on the horizontal shaft 5 via a bearing to be described later, 7 is an emitter or print head attached to this movable body 6 and equipped with an ink jetting mechanism, 8 is a platen, and 9 is a guide shaft provided on the upper part of the base 1 in parallel with the horizontal shaft 5, and guides the moving body in the horizontal direction.

Further, to describe this moving body with reference to FIGS. 2 to 5, the moving body is made of an insulating material, and a bearing hole 10 is formed in the longitudinal direction on one side of the moving body. A cylindrical bearing 11, which is a component of a bearing device and is made of a permanent magnet, is fitted therein.

A horizontal shaft 5 provided on the base 1 is inserted into the inner hole of the bearing 11.

In this case, an appropriate gap is formed between the horizontal shaft 5 and the bearing 11 over the periphery thereof.

In addition, a groove 12 that opens at the side surface is formed on the other side of the moving body, and a protrusion 13 is formed on the upper wall of the groove, and an auxiliary bearing 14 that engages with this protrusion 13 has a horizontal A guide shaft 9 provided parallel to the shaft 5 is inserted.

The bearing device is composed of the horizontal shaft 5 and the bearing 11 described above, and it is necessary that each of these has a magnetic force. For this purpose, for example, the horizontal shaft 5 and the bearing 11 each form a permanent magnet.

For example, as shown in FIG. 5, the horizontal axis 5 has an N pole at the top,
A permanent magnet is formed by magnetizing so that the S pole is located at the bottom of each magnet.

Further, the bearing 11 is magnetized so that the north pole is located at the upper part of the inner circumferential wall and the south pole is located at the lower part, thereby forming a permanent magnet.

Therefore, the same poles are located opposite to each other between the upper part of the horizontal shaft 5 and the upper part of the bearing 11 and between the lower part of the horizontal shaft 5 and the lower part of the bearing 11.

Between these mutually opposing magnetic poles, that is, the horizontal shaft 5 and the bearing 11
A strong magnetic repulsive force acts between the upper and lower parts of the bearing 11 that are opposed to each other, and the upper and lower parts of the bearing 11 are separated from the upper and lower parts of the horizontal shaft 5 due to this magnetic repulsive force.

In addition, this magnetic repulsion force acts not only on the upper and lower parts of the bearing 11 and the horizontal shaft 5, but also on the surroundings thereof, and the surroundings are also separated from each other, so that the bearing 11 and the horizontal shaft 5 as a whole The space between them constitutes a gap A.

However, because of the weight of the bearing 11 between the horizontal shaft 5 and the bearing 11, the bearing 11 descends to the upper part of the horizontal shaft 5.

Here, the gap between the horizontal shaft 5 and the bearing 11 narrows due to the lowering, and the magnetic repulsion between the two becomes even stronger, so that the two only make slight and light line contact at the upper part of the horizontal shaft 5.

Further, in the configuration of this embodiment, although the weight of the emitter 7 and the moving body 11 is added to the weight of the bearing 11, the weight applied to the horizontal shaft 5 is reduced because of the magnetic repulsion as described above.

Therefore, the moving body is supported in slight and light line contact with the horizontal axis 5.

Note that even if the upper part of the inner circumferential wall of the bearing 11 contacts the horizontal shaft 5,
As mentioned above, this is slight and light, so it does not interfere with the movement of the moving object at all.

Therefore, when the movable body is moved horizontally along the horizontal axis 5 by the drive mechanism via the wire, the movable body moves while maintaining a line contact support state with respect to the horizontal axis 5.

Here, even if the horizontal shaft 5 and the bearing 11 are deformed due to wear, the magnetic repulsion is acting between them, so they can maintain a line contact state, and the bearing 11 is attached to the horizontal shaft 5. The movement of the moving object will not be hindered by uneven hitting or close contact with the moving object.

In particular, when moving the moving body, the contact resistance between the bearing 11 and the horizontal shaft 5 is small, so it can be moved extremely lightly and smoothly, and the wear between the horizontal shaft 5 and the bearing 11 is reduced. The durability of each decreases and increases.

Further, while a strong magnetic repulsion force acts on the line contact portion between the horizontal shaft 5 and the bearing 11, a uniform magnetic repulsion force also acts on the gap between the horizontal shaft 5 and the bearing 11 other than the line contact portion. Therefore, the moving body can be stably supported.

Further, in order to support the moving body in slight and light line contact, magnetic poles were provided at least at the top and bottom of the horizontal shaft 5 and the bearing 11 in consideration of the load of the moving body, but the present invention is not limited to this. Alternatively, by providing magnetic poles at other positions to apply magnetic force, the magnetic force can be applied more reliably and uniformly between the two, so that the moving body can be stably supported.

Furthermore, either the horizontal shaft 5 or the bearing 11 may be made of a permanent magnet;
Instead of forming these as permanent magnets, small magnetic pole bodies may be implanted at predetermined locations on the horizontal shaft 5 and the bearing 11 to impart magnetic force to each. It is sufficient that it has magnetic force so that it can be positioned.

As explained above, the bearing device of the printing device of the present invention supports the movable body of the printing device, which performs printing while moving the movable body to which the print head is attached, along the axis, so as to be movable around the axis. In the bearing device of the printing device, either the shaft or the bearing is formed of a permanent magnet, or magnetic poles are provided opposite the shaft and the bearing in a direction perpendicular to the axial direction, so that a magnetic repulsion force is applied; Since the bearing is supported in slight and light line contact with the shaft, the contact resistance between the shaft and the bearing can be reduced, and the influence of friction during movement can be reduced.

Therefore, in a printing device that prints while a moving body is moved at a constant speed by a pulse motor, the friction between the shaft and the bearing is caused by the movement of the moving body in steps in response to the steps of the pulse motor. If is large, the moving body is likely to vibrate when it moves in steps, which may cause disturbances in printing, but in the bearing device of the present application, the friction between the shaft and the bearing is small. The movable body can be moved easily and smoothly, and there is no disturbance in printing caused by the print head, so that good printing can be performed.

It is particularly suitable for use in an ink jetting type recording device in which the head jets ink particles while moving.

In addition, when accelerating a stationary moving object to a constant speed, if the friction is large, the acceleration distance must be long; however, with the bearing device of the present application, the friction between the shaft and the bearing is small. Therefore, the moving object can be smoothly accelerated and the distance traveled can be shortened.

[Brief explanation of the drawing]

The drawings show an embodiment of the apparatus of the present invention, FIG. 1 is a schematic configuration diagram showing an ink jet recording apparatus, FIG. 2 is a front view showing a moving body of a printing apparatus using the apparatus of the present invention, and FIG. 3 is a cross-sectional view of the same, FIG. 4 is a longitudinal cross-sectional view of the same, and FIG. 5 is an explanatory view showing the state of action of magnetic force between the shaft and the bearing. 5...Horizontal axis, 6...Moving object, 7...
...Emitsuta, 9...Guide shaft, 11...
...Bearing, 14...Bearing, A...Gap.

Claims (1)

[Claims] 1. A bearing device for a printing device that movably supports a forward movable body of a printing device that performs printing while moving a movable body to which a print head is attached along a shaft by a pulse motor, the shaft being movably supported on the shaft. magnetic poles of different polarities are formed on at least the upper and lower parts of the shaft, and magnetic poles of the same polarity as the magnetic poles of the shaft are formed on the bearings of the moving body, facing the magnetic poles of the upper and lower parts of the shaft, and A bearing device for a printing device, wherein a magnetic repulsion force is applied between the bearing device and the bearing device.