KR100715857B1 - Heat Roller for Fixing Apparatus - Google Patents

Abstract

A heat roller for a fuser is disclosed. The heat roller is a conductive cylindrical roller body; A resistance heating element provided inside the roller body; Caps coupled to both ends of the roller body, each cap having electrodes for supplying current to the resistance heating element; And coupling means for restraining the at least one of the caps from turning in the roller body without being separated in the axial direction of the roller body.

Fuser, Heater, Fusing Roller, Gear Cap, Coupling Means

Description

Heat Roller for Fixing Machine {Heat Roller for Fixing Apparatus}

1 is a cross-sectional view of a heat roller for a general fixing device.

Figure 2 is an exploded perspective view of the gear cap side of the heat roller of Figure 1;

Figure 3 is an exploded perspective view of the gear cap side of another conventional heat roller.

4 is a cross-sectional view of FIG. 3.

5 is an exploded perspective view of the gear cap side of the heat roller according to the present invention.

FIG. 6 is a partial cutaway perspective view of the combined state of FIG. 5.

<Explanation of symbols for the main parts of the drawings>

100 ... Hitler

111 ... roller body

112 ... resistance heating element

114 .... Gear Cap

114a ... electrode

120 .... Joining means

121 ... Sticky Keys

122 ... coupling

124 ... engaging groove

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing unit for an image forming apparatus, and more particularly, to a heat roller of a fixing unit having a key that can prevent slippage in a roller cap portion during driving.

Image forming apparatuses such as laser printers, copiers and the like print and print desired images on paper through charging, exposure, development, transfer and fixing processes. In this process, the fixing process is a process of fixing a toner image transferred to a sheet by applying heat and pressure, and is usually performed by a mounting machine comprising a pair of opposed rollers.

One of the pair of rollers constituting the fixing unit is a pressure roller, and the other is a heat roller. The structure of a conventional heat roller is shown in FIG. Since the heat roller 10 shown in the drawing has a heat source, it requires a rotary power supply unit for supplying external power to the heat source. In the conventional heat roller, the rotary power supply unit includes an end cap (13) and a gear cap (gear cap) 14 mounted at both ends of the heat roller body 11, and It consists of connecting terminals 15 and 15 for electrically connecting the electrode and the heating source. Therefore, when the coupling of the gear cap and the end cap to the heat roller is not firm, the caps 13 and 14, in particular, the gear cap 14 are loosened, and the connection terminal 15 is twisted and broken. Therefore, it is necessary to fix the caps firmly.

Figure 2 is an exploded perspective view of the gear cap side of the heat roller of Figure 1; As shown in the figure, the gear cap 14 is normally fastened to the female screw portion 11b formed on the roller body 11 by forming the male screw portion 14b. Although not shown, the end cap 13 is also screwed.

However, even if the gear cap and the roller body in the heat roller of the fuser is coupled by a screw fastening method, the gear cap may be separated from the roller body during reverse rotation, and thus the electrodes 13a and 14a and the resistance heating element 12 may be separated. When the connecting terminals 15 and 15 connecting the twisted wires may cause a disconnection defect. In addition, the heat roller has a thickness of about 1 mm, and the height of the thread cannot be reduced to about 0.35 mm. Therefore, when the rotation torque of the roller is strong, the screw cap is crushed due to the screw thread being crushed, so that the disconnection or the contact of the terminal part is poor. There was a problem that sparks occur.

In order to solve this problem, the present applicant has been patented by proposing a fixing roller for fixing the roller body and the cap by a separate coupling means without screwing the gear cap (Korean Patent No. 452874).

3 and 4 are views of the gear cap side of the heat roller proposed by such a technique, FIG. 3 is an exploded perspective view, and FIG. 4 is a sectional view thereof. Referring to the drawings, the gear cap 24 is fastened to the roller body by the fixing ring 30 and the locking protrusion 32a at the body end of the heat roller 20. The fixing ring 30 is constrained so that the gear cap 24 does not deviate in the axial direction of the roller body 21, and the locking protrusion 32a inserted into the locking groove 31a is a gear cap constrained in the axial direction. 24 is constrained so as not to rebound from the roller body 21.

The fastening structure of the gear cap 24 is superior to the coupling force compared to the conventional screw fastening structure. However, as shown in the drawing, since the engaging groove 21b is formed in the roller body 21 to insert the fixing ring 30, groove processing is still applied to both ends of the body, thereby weakening the body. . Although the thinner the roller body can shorten the time to reach the printing temperature, that is, the first print out time (FPOT), there is a limit to the thinner the roller body for the above reason.

The present invention has been proposed to solve the above disadvantages of the prior art. SUMMARY OF THE INVENTION An object of the present invention is to provide a heat roller for a fixing apparatus which firmly maintains the coupling of the roller body and the cap by a new coupling means without screwing or grooving the roller body.

In order to achieve the above object, the fixing apparatus heat roller of the present invention comprises a conductive cylindrical roller body; A resistance heating element provided inside the roller body; Caps coupled to both ends of the roller body, each cap having electrodes for supplying current to the resistance heating element; And coupling means for restraining the at least one of the caps from turning in the roller body without being separated in the axial direction of the roller body.

The coupling means, the coupling portion protruding from the gear cap to be fitted to the roller body, the outer peripheral surface coupling portion formed with a predetermined depth; And a fixing key fitted into the coupling groove and having a plurality of protrusions formed on an outer circumferential surface thereof.

The coupling means may restrain the gear cap and / or the end cap.

The coupling groove may be an annular groove or a hexagonal or octagonal groove.

The fixed key is preferably composed of a semi-circular elastic key.

More preferably, the fixing key has an inner circumferential surface formed of a plurality of planes.

It is most preferable that the two fixing keys are installed in one cap facing each other.

It is preferable that an inner cap is mounted inside the caps.

The caps and the inner cap are preferably coupled by fastening means such as screws or bolts.

Bearings may be mounted on the outer circumferential surface of the roller body.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 5 is an exploded perspective view of the gear cap side of the heat roller according to the present invention, Figure 6 is a partially cut perspective view showing the coupled state.

Referring to the drawings, the filament heat roller 100 of the present invention includes a conductive cylindrical roller body 111; A resistance heating element (112) provided inside the roller body; Caps 114 coupled to both ends of the roller body and each having electrodes for supplying current to the resistance heating element; At least one of the caps includes a coupling means 120 for restraining from turning in the roller body without deviating in the axial direction of the roller body.

The coupling means 120, the coupling portion projecting from the cap 114 to be fitted to the roller body 111, the outer peripheral surface coupling portion 122 having a coupling groove 124 to a predetermined depth; And a fixing key (spring key) 121 fitted into the coupling groove 124.

The coupling means 120 may restrain the gear cap 114 and / or the end cap. The coupling groove 124 may be an annular groove or a hexagonal or octagonal groove.

The fixing key 121 has a plurality of protrusions 125 formed on the outer circumferential surface thereof, and the inner circumferential surface thereof has an annular shape or a hexagonal shape such as a hexagonal or octagonal shape, and more preferably a rectangular shape having a plurality of planes 123. It is made of. The protrusion 125 may have various shapes such as a triangle or a sawtooth shape, and preferably a triangular shape. The fixing key 121 may be formed in a semicircular shape. As shown in FIG. 5, the fixing keys 121 are most preferably installed in two caps facing each other. The fixing key is preferably made of a material having elasticity, for example, steel or steel alloy or stainless steel.

An inner cap 115 may be mounted inside the caps, and the cap 114 and the inner cap 115 are coupled by fastening means 117 such as a screw or bolt. An insulator 114b is provided on a side surface of the cap with the roller body, and an electrode 114a is mounted thereon.

A bearing 116 may be mounted on the outer circumferential surface of the roller body.

Since the roller body is firmly coupled by the fixing key, the heat roller 100 having the above-described coupling structure does not generate any waste in the axial direction of the roller as well as in the rotational direction of the roller.

On the other hand, in order to compare the performance of the heat roller 100 and the conventional heat roller 10 of the present invention, a gear chuck capable of snapping the cap was manufactured and a torque test was performed on each of them. .

As a result of the torque test, in the conventional heat roller, a screw thread was crushed at a torque of 30 to 35 kg · cm, and the coil was disconnected, whereas the heater of the present invention did not generate waste even at 163 to 167 kg · cm.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications may be made by those skilled in the art. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, in the fixing apparatus heat roller of the present invention, the roller body and the cap are more firmly coupled by the new coupling means, and thus there is no disconnection of the coil or spark generation between the electrodes, thereby extending the life of the heat roller. Can be.

Furthermore, the filament heat roller of the present invention does not use a screw thread, thereby reducing the cost of the roller body processing, and can further reduce the thickness of the roller body compared to the conventional one, thereby reducing the first print out time (FPOT). .

Claims (11)

delete delete delete delete Conductive cylindrical roller body; A resistance heating element provided inside the roller body; Caps coupled to both ends of the roller body, each cap having electrodes for supplying current to the resistance heating element; And And coupling means for restraining the at least one of the caps from retracting from the roller body without being separated in the axial direction of the roller body. The coupling means, A coupling portion which protrudes from the cap so as to be fitted to the roller body, and an outer circumferential surface of which a coupling groove is formed to a predetermined depth; And And a fixing key inserted into the coupling groove and having a plurality of protrusions formed on the outer circumferential surface so as to uniformly contact the inner circumferential surface of the roller body at a predetermined interval. delete Conductive cylindrical roller body; A resistance heating element provided inside the roller body; Caps coupled to both ends of the roller body, each cap having electrodes for supplying current to the resistance heating element; And And coupling means for restraining the at least one of the caps from retracting from the roller body without being separated in the axial direction of the roller body. The coupling means, A coupling part which protrudes from the cap so as to be fitted to the roller body, and an outer circumferential surface of the coupling groove has a predetermined depth; And It is fitted to the coupling groove, a plurality of protrusions are formed on the outer peripheral surface to uniformly contact the inner peripheral surface of the roller body at a predetermined interval, the inner peripheral surface is a rectangular key consisting of a plurality of plane; Heater for fixing unit. delete Conductive cylindrical roller body; A resistance heating element provided inside the roller body; Caps coupled to both ends of the roller body, each cap having electrodes for supplying current to the resistance heating element; And And coupling means for restraining the at least one of the caps from retracting from the roller body without being separated in the axial direction of the roller body. The coupling means, A coupling part which protrudes from the cap so as to be fitted to the roller body, and an outer circumferential surface of the coupling groove has a predetermined depth; And And a spring key inserted into the coupling groove and having a plurality of protrusions formed on the outer circumferential surface so as to uniformly contact the inner circumferential surface of the roller body at a predetermined interval. Heater for the fuser, characterized in that the inner cap (inner cap) is mounted on the inside of the caps. delete The method of claim 9, The cap and the inner cap is a heat roller for the fuser, characterized in that coupled by the fastening means.

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