JP2002229362A - Fixing device for image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device for an image forming device capable of realizing the improvement of the assemblability of a heating heater for the fixing device of the image forming device, and preventing the increase of contact resistance between the power receiving terminal part and the power supply holder member of the heating heater. SOLUTION: This fixing device is equipped with a pair of power supply holder members 20A and 20B holding the heating heater 16 by pressing a pair of power receiving terminal parts 22 and 22 provided at both ends of the heater 16 by elastic force from both sides, also supplying power from a power source to the heater 16 and set so that the elastic force of either one may be smaller than that of the other, and an attachable/detachable reinforcing pressing member 25 pressing to reinforce the elastic force of the member 20B whose elastic force is smaller out of a pair of members 20A and 20B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic method, such as a printer, a copying machine, and a facsimile, and more particularly to an improvement in a fixing device.

[0002]

2. Description of the Related Art As a fixing device of a conventional image forming apparatus, for example, there is one as shown in FIG. In the figure, a cylindrical heating roller 12 for heating and melting the heat-soluble toner is rotatably provided at the upper part, and an elasticity for pressing the toner paper against the heating roller 12 is provided below the heating roller 12. A body pressure roller 14 is rotatably provided. Such a heating roller 12
Device 1 of the image forming apparatus by means of pressure roller 14
0 is mainly configured.

A heating heater 16 (see FIG. 8) having a nichrome wire provided in a glass tube is disposed on the axis of the heating roller 12. The heating roller 12 is detachably provided in a casing 18 fixed in the image forming apparatus, and the heating heater 16 is detachably provided in the heating roller 12.

That is, as shown in FIG.
A pair of power supply holder members 20, 20 connected to a power supply (not shown) are provided inside both end portions of the heater 8.
The power receiving terminals 22, 22 at both ends of No. 6 are pressed and held from both sides by elastic force.

As a result, the power supply holder member 20,
20 can hold the heater 16 and supply power from a power source (not shown) to the heater 16 via the power receiving terminals 22 and 22. By the way, in FIG. 8, the illustration of the heating roller 12 around the heating heater 16 is omitted for convenience.

As another conventional fixing device of an image forming apparatus, there is one as shown in FIG. In this conventional fixing device, a pair of flat mounting terminals 32, 32 are connected to the power receiving terminal portions 22, 22 of the heater 16, and each of the mounting terminals 32, 32 is connected to a power supply (not shown). A pair of washer-shaped flat terminals 34, 34 and screws 36, 36
Are attached to each of the support members 38, 38 by being fastened together.

[0007]

However, in the conventional fixing device shown in FIG. 8, since the pair of power supply holder members 20 have the same magnitude of elastic force, the pair of power supply holder members 20, 20 have the same elastic force. In order to prevent the contact resistance between the power receiving terminal portions 22 and 22 from increasing by making the pressing force between the power receiving terminal portions 22 and 22 equal to or higher than a predetermined pressure F, the power supply holder members 20 and 2 may be used.
When temporarily assembling with the heater 16 being sandwiched between the zeros, a force larger than the above-mentioned pressure F is required, and as a result, there has been a problem that the assemblability is significantly deteriorated.

Further, when the power supply holder members 20, 20 are deformed with such a large force, the power supply holder members 20, 20 are deformed beyond the elastic region into the plastic region.
When the deformation of the power supply holder members 20, 20 is reduced to a position where the tip thereof contacts the power receiving terminal portions 22, 22 of the heater 16 due to the repulsive force of the power supply holder members 20, 20, Cannot generate a pressure F equal to or higher than a certain value, the contact resistance between the power supply holder member 20 and the power receiving terminal portion 22 increases, and the power from the power supply holder member 20 to the power receiving terminal portion 22 is reduced. There was a problem that supply was hindered.

Further, in the conventional fixing device shown in FIG. 9, the man-hour for tightening the flat terminal 34 connected to the power supply together with the mounting terminal 32 by the screw 36 is increased, and the assemblability is deteriorated. In addition, there is a problem that the space is required and the number of components increases because the mounting terminals 32 and the flat terminals 34 are provided, which leads to an increase in cost.

In view of the above problems, the present invention can improve the assemblability of the heater to the fixing device, and can reduce the contact resistance between the power receiving terminal portion of the heater and the power supply holder member. It is an object of the present invention to provide a fixing device of an image forming apparatus, which can prevent increase in cost and increase in cost.

[0011]

In order to solve the above-mentioned problems, a fixing device of an image forming apparatus according to the present invention fixes a heat-soluble toner transferred from a photosensitive member or an intermediate transfer member onto a sheet on the sheet. A fixing device, a heating roller that performs the fixing operation while feeding the sheet by rotating the sheet across the sheet, a heating heater that is provided inside the heating roller and heats the heating roller, and both ends of the heating heater A pair of power receiving terminal portions provided in the portion, the pair of power receiving terminal portions are pressed by elastic force from both sides to hold the heater, and supply power from a power source to the heater to supply at least one elastic force. A pair of power supply holder members each having a force smaller than a predetermined elastic force; and a power supply holder having a smaller elastic force among the pair of power supply holder members. A detachable reinforcing pressing member that presses to reinforce the elasticity of the member, wherein when the heating heater is temporarily assembled between the pair of power supply holder members, the reinforcing pressing member is not attached; Is tentatively assembled between the pair of power supply holder members, and then the reinforcing pressing member is attached.

According to the fixing device of the image forming apparatus having such a configuration, the elastic force of at least one of the pair of power supply holder members is smaller than the predetermined elastic force, and the power supply holder member having the smaller elastic force is used. A detachable reinforcing pressing member that reinforces the elastic force of the heater. When the heater is temporarily assembled between the pair of power supply holder members, the reinforcing pressing member is not attached, and the heater is connected between the pair of power supply holder members. Since the reinforcing pressing member is attached after temporarily assembling, when the heater is temporarily assembled to the fixing device, the power supply holder member with the smaller elasticity is easily deformed, so it is easily attached and assembled. It is possible to enhance the elasticity of the power supply holder member having the smaller elastic force after the temporary assembly so that the reinforcing pressing member reinforces the elastic force. Accordingly, it is possible to contact resistance between the power-receiving terminal portion and the power supply holder member of heater is prevented from increasing. In addition, since the number of components does not increase significantly, it is possible to prevent an increase in the number of mounting steps, deterioration in assemblability, and an increase in cost.

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. 1 to 4
FIG. 1 is a diagram referred to for describing an embodiment of a fixing device of an image forming apparatus according to the present invention. The same components as those of the fixing device of the conventional image forming apparatus are denoted by the same reference numerals, and the description thereof will not be repeated.

FIG. 1 is a view showing a fixing device 30 of an image forming apparatus according to one embodiment of the present invention. Its configuration is basically the same as that of the fixing device 10 of the conventional image forming apparatus shown in FIG.
The elastic force (elastic coefficient) of 0B is the power supply holder member 20A.
Is smaller than the predetermined elastic force, and a spacer 25 (reinforcement pressing member) is inserted (sandwiched) between the power supply holder member 20B and the casing 18 having the smaller elastic force. ) Is provided.

Since the spacer 25 is inserted and provided in this manner, even if the elasticity of the power supply holder member 20B is smaller than that of the power supply holder member 20A, it can be reinforced. The pressing force between the power supply holder members 20A and 20B in a reaction relationship becomes a pressure F which is equal to or greater than a predetermined value (approximately 2 kgf or more). This pressure F is the power reception between the power supply holder members 20A and 20B and the heater 16. It is also a pressing force between each of the terminal portions 22 and 22.

For this reason, the above-mentioned predetermined pressure F is applied to each of the power supply holder members 20A and 20B and the power receiving terminal portion 2.
The contact resistance value between the power supply holder members 20A and 20B can be supplied to the heater 16 through the power receiving terminal portion 22 without any problem.

The method of assembling the fixing device 30 of the image forming apparatus will be described below with reference to FIGS. As shown in FIG. 2, the power supply holder members 20A,
Before the heater 16 is mounted between the heaters 20B, the distance between the ends of the power supply holder members 20A and 20B is different from the distance between the power supply holder members 20A and 20B of the power receiving terminal portions 22 and 22 at both ends of the heater 16. It is smaller than the interval between the contact portions.

The power supply holder members 20A, 20B
When the heater 16 is temporarily assembled in the middle, the power supply holder member 20B has a smaller elastic force than the power supply holder member 20A and thus is easily deformed. By arranging the heater 16 so that the distance between the power supply holder members 20A and 20B is larger than the length of the heater holder 16 and then weakening the force for deforming the power supply holder member 20B to reduce the deformation, as shown in FIG. Power supply holder member 20
The heater 16 is temporarily assembled and supported between A and 20B.

When the heater 16 is temporarily assembled to the fixing device 30 of the image forming apparatus, the power supply holder member 20B having the smaller elasticity is easily deformed, so that the heater 16 can be easily attached. Therefore, the assemblability of the fixing device 30 can be improved.

Next, the power supply holder member 20 shown in FIG.
As shown in FIG. 1, the spacer 25 is inserted from above into the gap C between the casing B and the casing 18 so as to widen the gap C so that the tip of the power supply holder member 20B is heated by a heater. 16 toward the power receiving terminal portion 22.

As described above, the elastic force of the power supply holder member 20B having a smaller elastic force is reinforced and pressed by the spacer 25, so that the power supply holder members 20A and 20B which have an action and a reaction relation with each other. Of the power supply holder member 20
A, 20B and the pressing force between each of the power receiving terminals 22, 22 of the heater 16.

For this reason, the pressure F above a certain level is applied to each of the power supply holder members 20A and 20B and the power receiving terminal 2.
2, the contact resistance value between the power supply holder members 20A and 20B can be supplied to the heater 16 via the power receiving terminal portion 22 without any problem.

By the way, as shown in FIG.
Spacer 2 so that the thickness of the taper gradually decreases toward the tip
Since the inclined surface 25a is formed at the tip of the spacer 5, the spacer 25 can be smoothly inserted into the gap C.

A projection 25b is formed at the rear end (upper end in FIG. 1) of the spacer 25 so as to project in a direction perpendicular to the length direction of the spacer 25. When completely inserted into the gap C, the protruding portion 25b shields the distal end portion of the power supply holder member 20B, so that the finger of the hand erroneously moves when the spacer 25 is inserted. 20B can be prevented from touching.

As shown in FIG. 4, a notch 18 is formed in the wall plate portion 18a of the casing 18 on the front side of the spacer 25.
b is formed, and the protrusion 25 of the spacer 25 is formed.
b also extends into the notch 18b of the front wall plate portion 18a, and when the spacer 25 is completely inserted,
Between the notch 18b and the protruding portion 25b, a wiring hole 34 through which the wiring 32 connected from the power supply holder member 20B to the power supply is formed. Therefore, the wiring 32 can be easily fixed in the wiring hole 34 so that the wiring 32 does not move after the fixing device 30 is assembled, and the assemblability of the wiring 32 can be improved.

In the above-described embodiment, the spacer 25 is used as the reinforcing pressing member for reinforcing the elastic force of the power supply holder member 20B having the smaller elastic force. A leaf spring member 41 or a disc spring (not shown) as shown in FIG.

In the above-described embodiment, the case has been described where only one of the pair of power supply holder members 20A and 20B has a smaller elastic force than the predetermined elastic force. The elastic force of both power supply holder members 20A and 20B may be smaller than a predetermined elastic force, and a pair of spacers 25 may be inserted between them and the casing 18.

As shown in FIG. 6, a fillet M is formed in a part (a bent portion) of the power supply holder member 20B 'having a smaller elastic force without using such a reinforcing pressing member. By making the bent part of the lever undeformable,
The elasticity of the power supply holder member 20B 'as a whole may be increased to obtain a pressure F equal to or higher than a predetermined value.

Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and based on the technical idea of the present invention, various other embodiments are possible. Can be changed.

[0030]

As described above, according to the fixing device of the image forming apparatus of the present invention, when the heater is temporarily assembled to the fixing device, the power supply holder member having the smaller elastic force is easily deformed. As a result, it is possible to easily mount the power supply holder member and improve the assemblability of the power supply holder member. It is possible to prevent the contact resistance between the receiving terminal portion and the power supply holder member from increasing. Also, since the number of parts does not increase significantly,
Deterioration of assemblability or increase in cost can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a fixing device 30 of an image forming apparatus according to an embodiment of the present invention, partially cut away.

FIG. 2 is a schematic side view partially cut away for explaining a method of assembling the fixing device 30 of FIG. 1;

FIG. 3 is a schematic side view partially broken away for explaining an assembling method of the fixing device 30;

FIG. 4 is a schematic side view showing the fixing device 30 partially cut away as viewed from outside the wall plate portion 18a.

FIG. 5 is a schematic side view of a fixing device according to another embodiment, in which a leaf spring member 41 is used in place of the spacer 25, with a part cut away.

FIG. 6 is a schematic side view, partially broken away, for explaining still another embodiment.

FIG. 7 is a front sectional view of a fixing device 10 of a conventional image forming apparatus.

FIG. 8 is a schematic side view of a fixing device 10 of a conventional image forming apparatus, partially cut away.

FIG. 9 is a schematic side view showing a fixing device of another conventional image forming apparatus, partially cut away.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fixing device 12 Heating roller 14 Pressure roller 16 Heater 18 Casing 18a Wall plate 18b Notch 20, 20A, 20B Power supply holder member 22 Power receiving terminal 25 Spacer 25b Projection 30 Fixing device 32 Wiring 34 Wiring Hole 41 Leaf spring member C Gap M Fillet

Claims (4)

[Claims] 1. A fixing device for fixing a heat-soluble toner transferred from a photoreceptor or an intermediate transfer member onto a sheet on a sheet, wherein the fixing operation is performed while feeding the sheet by rotating the sheet across the sheet. A heating roller to be performed, a heating heater provided inside the heating roller to heat the heating roller, a pair of power receiving terminals provided at both ends of the heater, and the pair of power receiving terminals from both sides. A pair of power supply holder members, which are pressed by an elastic force to hold the heater and supply electric power from a power supply to the heater to make at least one elastic force smaller than a predetermined elastic force; A detachable reinforcing pressing member that presses so as to reinforce the elastic force of the power supply holder member having the smaller elastic force among the members; When the heater is temporarily assembled between the pair of power supply holder members, the reinforcing pressing member is not attached. After the heater is temporarily assembled between the pair of power supply holder members, the reinforcing pressing member is attached. A fixing device for an image forming apparatus, comprising: 2. The fixing device of an image forming apparatus according to claim 1, wherein an inclined surface is formed at a front end portion of the reinforcing pressing member so that the thickness of the reinforcing pressing member gradually decreases toward the front end. 3. The reinforcing pressing member according to claim 1, wherein a projection for shielding at least the power supply terminal member near the reinforcing pressing member when the reinforcing pressing member is attached is provided at a rear end of the reinforcing pressing member. Fixing device of the image forming apparatus. 4. A projecting portion which forms a part of a wiring hole through which a wiring connected to the power supply passes when the reinforcing pressing member is attached is provided at a rear end of the reinforcing pressing member. 2. A fixing device for an image forming apparatus according to claim 1.