JPH08272239A - Fixing device for copying machine or the like - Google Patents

Abstract

PURPOSE: To improve reliability of a contact and to prevent damage to this device when a heater is thermally expanded and is subjected to vibration and impact by providing an expansion and contraction absorbing bent part with a obtain spring property at a part. CONSTITUTION: At the time of supporting the heater 1 by a heater support 2, platelike terminals 3 provided on both ends of the heater 1 are used as attaching parts for the heater support 2 and each of the attaching parts is fixed by a screw, to support the heater 1. Each of the platelike terminals 3 as the attaching parts provided on both ends of the heater 1 is composed of a fixing part 4 and the expansion/contraction absorbing bent part 5. A thread groove or oblong hole for fixing the terminal 3 on the heater support 2 by the screw is formed in the end part of the fixing part 4. The bent part 5 provided between the heater 1 and the fixing part 4 is formed like a V- or U-shape and the expansion of the heater 1 or the heater support 2 is absorbed by the spring of the bent part 5, to prevent the damage of the heater 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device such as a copying machine, and more particularly to a heater mounting structure for the fixing device.

[0002]

2. Description of the Related Art As a mounting method of a heater of a fixing device of a copying machine, Japanese Patent Laid-Open No. 3-252689 discloses a heater 53 in a fixing roller 52 supported by a frame 51, as shown in FIG. To elastically support
A method is disclosed in which a spring member 54 that presses the heater 53 in the direction of arrow A is interposed, a terminal 55 made of a lead wire is sandwiched between a conductive plate 56 and a cover 57, and a screw 58 is fastened to absorb the extension due to thermal expansion. .

Further, in Japanese Patent Laid-Open No. 4-316073, as shown in FIG. 4, the heater 43 in the heat roller 42 supported by the supporting member 41 is supported by the elastic force of the leaf spring 44. There is disclosed a method in which the electrode terminal 45 provided on the heater 43 is formed by a deformable nickel-plated copper wire, the electrode terminal 45 is sandwiched by a contact plate 46, and the screw 47 is tightened.

Further, as shown in FIG. 3, flat-plate terminals 32 are provided at both ends of the heater 31, and the flat-plate terminals 3 are provided.
It has also been proposed to fix the heater 31 to the heater support 33 with screws 34 to support and fix the heater 31.

[0005]

In the techniques described in both the above publications, the structure is complicated because the thermal expansion of the heater is absorbed by pressing the heater against the case or the support by a spring, and the heater is also complicated. Since the terminal is a lead wire, there is a drawback that foreign matter may enter the gap between the lead wire and the contact portion, or that the terminal and the contact portion are easily oxidized to cause poor contact, causing sparking and separation.

Next, in the case of the heater having the above-mentioned flat terminals at both ends, when both ends of the heater are fixed to the heater support, a tensile force or a compressive force is applied to the heater due to a difference in thermal expansion between the heater and the heater support. , The heater is damaged. Further, in fixing the flat plate-shaped terminal, it is necessary to align the long hole of the flat plate-shaped terminal with the screw hole provided in the support, so that there is a drawback that it takes time to position the terminal.

Therefore, the present invention has a heater structure that improves the reliability of the contacts, does not break even when the heater is thermally expanded and is subjected to vibrational shock, and a heater mounting structure that facilitates positioning during terminal mounting. Is provided.

[0008]

According to the present invention, a fixing device for fixing terminals at both ends of a heater with a screw is provided with an expansion and contraction absorbing bending portion to have a spring property.
Expansion and contraction due to thermal expansion during heating or cooling of the heater is absorbed in the axial direction of the heater.

Further, by providing the heater support with the protrusions, the flat terminals are dropped between the protrusions and fixed by screws, so that the heater can be prevented from being damaged by the spiraling of the terminals.

[0010]

According to the present invention, the expansion and contraction absorbing bending portion formed on the flat plate terminal of the heater absorbs the expansion and contraction due to the elasticity of the expansion and contraction absorbing bending portion even when the heater and the heater support expand and contract due to thermal expansion. By providing the support with a protrusion into which the flat terminal can be inserted, when the flat terminal is tightened with a screw, the rotation of the heater is restricted by the protrusion, so that it is possible to prevent whirling of the heater. With
Can firmly fix the fence plate terminal.

[0011]

Embodiments of the present invention will be described in detail below with reference to the drawings.

According to the present invention, when the heater 1 is supported on the heater support 2 as shown in FIG.
The plate-like terminals 3 provided at both ends of the are used as mounting portions for the heater support 2, and the mounting portions are screwed and supported. The flat plate-shaped terminals 3 provided at both ends of the heater 1 and serving as mounting portions are composed of a fixing portion 4 and an expansion / contraction absorbing bending portion 5. A screw groove 6 or an elongated hole for screw-fixing the flat terminal 3 to the heater support 2 is formed at the end of the fixing portion 4. As shown in FIG. 2, the expansion / contraction absorption bending portion 5 provided between the heater 1 and the fixed portion 4 is formed into a V shape (FIG. 1a) or a U-order shape (FIG. 1b). The elasticity of the heater 1 absorbs the expansion and contraction of the heater 1 and that of the heater support 2 to prevent the heater 1 from being damaged.

As shown in FIG. 3, the heater support 2 is formed with a projection 7 into which the flat terminal 3 can be inserted, and the flat terminal 3 is dropped between the projections and screwed. Fix it. When the protrusion 7 is provided with a taper at the top on the side where the flat plate terminal 3 is fitted and inserted, the flat plate terminal 3 can be guided by a hand and dropped into the space between the projections more easily. The protrusion 7 allows the flat plate terminal 3 to be easily positioned and prevents whirling when screwing.

[0014]

The effects of the present invention are as follows.

1) The expansion and contraction due to the thermal expansion of the heater and the thermal expansion of the support are absorbed by the elasticity of the expansion and contraction absorbing bending portion formed in the flat plate-like terminal, so that an axial tensile force and a compressive force are generated in the heater. Since it does not happen, the heater will not be damaged even if it gets hot.

Further, even if the positional accuracy such as the parallelism on both sides of the heater mounting surface varies, the variation can be absorbed by twisting the terminal by the expansion and contraction absorbing bending portion.

2) The expansion / contraction absorbing / bending portion can be formed by a simple sheet metal working by simply bending it into a V-shape or a U-shape, and has a simpler structure than the conventional means for absorbing thermal expansion / contraction. , Reliability is also improved.

3) When the heater is attached to the heater support by providing a protrusion on the heater support,
Positioning can be done easily by simply dropping the flat plate terminal, and when fixing the flat plate terminal with a screw, the protrusion prevents the flat plate terminal from twisting. Since the terminal and the contact part can be firmly tightened and fixed, the reliability of the contact is improved.

[Brief description of drawings]

1A and 1B are explanatory views of a heater having a flat terminal according to the present invention, FIG. 1A is a plan view, and FIG. 1B is a front view.

2 is a plan view of a flat terminal according to the present invention, FIG.
Is an explanatory view of a V-shaped stretchable bending portion, and FIG. 2b is an explanatory view of a U-shaped stretchable bending portion.

FIG. 3 is an explanatory view of a conventional first heater support structure.

FIG. 4 is an explanatory view of a conventional second heater support structure.

FIG. 5 is an explanatory view of a third conventional heater support structure.

[Explanation of symbols]

1 heater, 2 heater support, 3 flat terminal, 4 fixed part, 5 expansion and contraction absorption bending part, 6 screw groove, 7 protrusion, 31 heater, 32 flat terminal,
33 heater support, 34 screw, 41 support member, 42 heat roller, 43 heater, 44
Leaf spring, 45 electrode terminal, 46 contact plate, 47
Screw, 51, frame, 52 fixing roller, 53
Heater, 54 spring member, 55 terminal, 56
Conductive plate, 57 cover, 58 screws

Claims (3)

[Claims] 1. The heater has both electrode terminals formed in a flat plate shape to be a mounting portion to the heater support, and the mounting portion is formed by a fixing portion to the support and an expansion / contraction absorbing bending portion. Fixing device such as copier. 2. The fixing device for a copying machine or the like according to claim 1, wherein the expansion / contraction absorbing bending portion is bent in a V shape or a U shape. 3. The fixing device for a copying machine or the like according to claim 1, wherein a terminal rotation preventing projection is provided on the terminal mounting portion of the heater support.