JPS58180Y2 - heat roll - Google Patents

Description

[Detailed description of the invention] This invention relates to a heat roll used in the fusing section of copying machines, etc. The purpose of this invention is to improve the structure of the heat roll so that the set temperature is stable and the power consumption is low. They have rolls to offer.

In this case, when the thermistor used as a heat generating element is composed of a plurality of small pieces that fit into support holes provided in the support tube, an effect can be obtained in that it can be locally repaired.

Furthermore, the structure can be simplified by configuring the thermistor as a whole into one cylinder.

This invention will be explained in detail below based on the illustrated embodiments.

In the figure, numeral 1 is a cylindrical aluminum tube,
A thin rubber layer 2 is pasted (or may be baked) on its outer periphery.

A boss tube 4 equipped with a trunnion 3 is fixed to both ends of the aluminum tube 1 by screws 5, and between the boss portions 4, 4, the inside of the aluminum tube 1 is provided with a trunnion 3. A support cylinder 6 having an outer diameter slightly smaller than the inner diameter is fitted.

The support tube 6 has boss portions 8 fixed at both ends with screws 7, and a support shaft 9 provided on the boss portion 8 is removably inserted into a center hole 10 bored in the boss portion 4. has been done.

The support cylinder 6 has oval support holes 11 on its outer peripheral surface.
... are formed in a staggered manner at a predetermined pitch, and a small piece thermistor 12 ... is inserted as a heating element into each of the support holes 11 .... .

The leaf springs 13 are inserted into the bottoms of the support holes 11, and the thermistors 12 are supported, and the thermistors 12 are , are individually press-welded to the inner circumferential surface of the aluminum cylinder 1.

In the figure, reference numeral 14 is a shaft bearing, and 15 is a transmission sprocket.

In such a configuration, the thermistor 12 is in close contact with the inner wall of the aluminum cylinder 1, so it has good thermal conductivity, has almost no thermal gradient like nichrome wire, and can achieve uniform heat generation as a whole. , temperature control is also done using thermistor 1.
2... Since the intermediate rest period is automatically adjusted, temperature changes are small and temperature stability as a heat roll can be ensured.

Furthermore, since the thermistor is used, power consumption can be reduced compared to the case where a resistance wire is used, which is economical.

Additionally, even if a thermistor fails locally during use, only the corresponding failed thermistor needs to be replaced, making repairs easier and cheaper than replacing the entire nichrome wire as in the past. .

The thermistor 12 has a small piece shape with a flat surface;
A slight gap is created between the aluminum cylinder 1 and the thermistor 12, resulting in a decrease in thermal conductivity.

Therefore, by forming the surface of the thermistor in the same arc shape as the inner wall of the aluminum tube 1 as shown in FIG. , the thermal conductivity is further improved, and the surface temperature of the thermo roll can be raised to a predetermined temperature in a short time.

In the above embodiment, an aluminum tube was used as the metal tube, but it goes without saying that other materials such as a copper alloy or an aluminum alloy may also be used.

Silicone rubber is optimal for the thin rubber layer 2 from the viewpoint of heat resistance.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing an embodiment of this invention, Fig. 2 is a developed view of the support tube, Fig. 3 is an enlarged longitudinal sectional view of the main parts, and Fig. 4 is an enlarged longitudinal sectional view of the main parts.
Figures a and l) are shape diagrams of the thermistor, and Figure 5 is a cross-sectional front view of the main parts. 1... Aluminum tube, 2... Rubber layer, 3... Trunnion, 4... Boss part,
5... Screw, 6... Support tube, 7...
... Screw, 8 ... Boss part, 9 ... Support shaft, 10 ... Center hole, 11 ... Support hole, 12 ... ...Thermistor, 13...Plate spring, 14...Shaft bearing, 15...Transmission sprocket.

Claims (1)

[Scope of utility model registration request] A plurality of thermistors are arranged at equal intervals as heat generating elements inside a metal cylinder with a rubber layer pasted on the surface, the thermistor is provided with a support cylinder with a slight gap inside the metal cylinder, 1. A hot roll, which is fitted into support holes formed in the support cylinder at a predetermined pitch, and is held in pressure contact with the inner wall surface of the metal cylinder by a spring member.