JPS63157181A - Fixing device - Google Patents

Abstract

PURPOSE:To easily manufacture the titled device, and also, to reduce its cost by providing a positioning part for controlling the fitting-in depth of a bearing on both end parts of a metallic pipe of a pressure roller having an elastic member on the outside peripheral surface. CONSTITUTION:A pressure roller 3 for pressing an image carrying body against a heat roller is constituted of an elastic member 21 formed along the outside peripheral surface of a metallic pipe 20 functioning as a mandrel, and a bearing 22 is fitted into the inside diameter part of both its ends. The pressure roller 3 is supported so as to be freely rotatable by a supporting lever 25 through a supporting shaft 30 fitted into the bearing 22. In the inside diameter part of both ends of the pipe 20, a positioning part 35 consisting of plural emboss parts 33, or stepped parts 34 is formed, the fitting-in depth into the pipe 20 of the bearing 22 is controlled. As for the bearing 22, a usual inexpensive bearing an be used, and welding work of flanges to both end parts of the pipe is also unnecessary, by which an inexpensive fixing device which can be manufactured easily can be offered.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to a fixing device applied to image forming VRM of electronic copying machines, electronic printers, etc., and particularly relates to a fixing roller and its fixing device. This invention relates to an improvement in a fixing device comprising a pressure roller mechanism that presses an image support against a fixing roller.

(Prior Art) Usually, this type of fixing device is equipped with a heat roller b having a built-in heater lamp a as a fixing roller, as shown in FIG.
and a pressure roller mechanism C that presses an image support P such as transfer paper against the heat roller b.

Further, in the conventional fixing device, the pressure port-ra mechanism C has a structure as shown in detail in FIGS. 7 and 8.

That is, h is a pressure roller that can be in rolling contact with the heat roller b, and this pressure roller h is welded to a metal pipe serving as a core metal so as to close the openings at both ends of this metal pipe f. A flange e having axes d and d integrally at the center of the outer wall surface.

e, and an elastic member Q formed along the outer peripheral surface of the pipe f.

Further, the above-mentioned shaft d protrudes from the flanges e and e.

Grooved bearings i, i are mounted on d, and these grooved bearings i, i are supported by a pair of support levers n, n.

The support levers n, n have an engaging portion k formed on one end side.
can be rotated freely with the rotation fulcrum, and the free end side is a compression spring r
, r[, and there is a grooved bearing i in the middle.

A notch m is formed along the outer periphery of the groove into which the groove bottom j is inserted.

Thus, the pressure roller h is always pressed against the heat roller b, and the heat roller b is rotated at the same time by being rotationally driven by a drive system (not shown). The developer image (toner image) S on the image support P passing between the heat roller b and the pressure roller h is fixed by temperature and pressure.

(Problems to be Solved by the Invention) However, with such a conventional configuration, the flanges e and e must be welded to both ends of the pipe f, resulting in extremely poor workability and high manufacturing costs. , it is necessary to use a rather expensive grooved bearing 1, which has been a major obstacle in reducing the cost of the fixing device.

The present invention has been made based on the above circumstances, and an object thereof is to provide a fixing device that is easy to manufacture and is low in cost.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the present invention provides a fixing roller,
and a pressure roller mechanism that presses the image support member against the fixing roller, and fixes an unfixed developer image formed on the surface of the image support member, the pressure roller mechanism comprising a metal pipe. a pressure roller whose outer peripheral surface is coated with an elastic member; bearings having outer diameter portions fitted into the inner diameter portions of both ends of the pipe of the pressure roller; and bearings rotatably provided at both ends of the pressure roller; A pair of support levers having a support shaft that fits into the inner diameter of the bearing, and a biasing member that biases the support levers so that the pressure roller comes into pressure contact with the fixing roller. It is.

(Function) That is, the present invention, with the above configuration, eliminates the need for welding the flanges to both ends of the pipe, which was conventionally done, and also eliminates the need for two flanges. Furthermore, it is possible to use ordinary inexpensive bearings instead of special specification bearings such as relatively expensive grooved bearings. This makes manufacturing easy and
Moreover, it is cheap! Equipment can be provided.

(Example) An example of the present invention will be described below with reference to FIGS. 1 to 5.

In FIG. 1, 1 is a heat roller as a first fixing roller with a built-in heater lamp 2, and 3 is a pressure roller as a second fixing roller that constitutes a part of a pressure roller mechanism 4, which will be described later. .

These rollers 1.3 roll into contact under constant pressure, and when the beat roller 1 is rotationally driven in the direction of the arrow in the figure by a drive means (not shown), the pressure roller 3 is also rotated.

By passing the image support P between the heat roller 1 and the pressure roller 3, the developer image (toner@) S on the image support P is fixed by temperature and pressure.

Also, a peeling claw 5. is provided opposite to the peripheral surface of the heat roller 1.
A cleaning felt 6, a temperature fuse 7, a thermistor 8, etc. are provided, and the image support P in the fixing method can be peeled off smoothly, and the heat roller 1
It can be used to remove dirt and control the temperature.

In addition, 15 is belt 10. This is an image support transport path formed by guide plates 11 and 12, a discharge roller 13, and the like.

Further, the pressure roller mechanism 4, which includes the pressure roller 3 described above and presses the image support P against the heat roller 1, has the following configuration.

That is, as shown in FIGS. 2 to 4, the pressure roller 3 is composed of a metal pipe 20 made of aluminum, iron, etc., which serves as a core metal, and an elastic member 21 formed along the outer peripheral surface of the pipe 20. Bearings 22 and 22 are fitted (press-fitted) into the inner diameter portions of both ends of the pipe 2o.

Further, support levers 25.25 are disposed on both ends of the pressure roller 3, and have an engaging portion 23 serving as a rotational fulcrum at the lower end of one end, and a spring support portion 24 at the lower end of the other end. ,
These support levers 25° 25 are connected to the engaging portion 2, respectively.
3 is engaged with the support shaft 26 to be rotatably supported.

Support shafts 30.30 are protruded from the midway portions of these support levers 25.25 and from mutually opposing surfaces, and by fitting these support shafts 30.30 into the inner diameter portions of the bearings 22.22, pressure can be increased. The roller 3 is rotatably supported.

Further, the support lever 25.25 is such that the other end side (free end side) is pushed up by a compression spring 31. 3 is in pressure contact with the heat roller 1.

In addition, the inner diameter portions of both ends of the pipe 20 are provided with, for example,
A positioning part 35 consisting of a plurality of embossed parts 33 as shown in a> or a stepped part 34 as shown in FIG. This prevents the inserted bearing 22 from shifting inward when the support shaft is inserted.

Therefore, in the fixing device having the above structure, there is no need for welding the flanges to both ends of the pipe, which was conventionally done, and two flanges are also no longer necessary. Furthermore, it is possible to use ordinary inexpensive bearings instead of special specification bearings such as relatively expensive grooved bearings. This makes it possible to provide a constant l device that is easy to manufacture and inexpensive. Also, it is possible to reduce the number of parts, thereby making the device lighter in weight.

Note that the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

"Effects of the Invention" As explained above, according to the present invention, the conventional work of welding flanges to both ends of a pipe is no longer necessary, and two flanges are also no longer necessary.

Furthermore, it is possible to use ordinary inexpensive bearings instead of special specification bearings such as relatively expensive grooved bearings. As a result, it is possible to provide an inexpensive fixing device that is easy to manufacture.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention,
Fig. 1 is an explanatory diagram schematically showing the overall structure of the fixing device, Fig. 2 is a perspective view of the pressure roller mechanism, which is the main part, Fig. 3 is an exploded perspective view, and Fig. 4 is partially omitted. 5 is a schematic plan view shown in FIG. FIG. 7 is a partially cutaway sectional view of the main part, and FIG. 8 is a perspective view showing the installation state with some parts omitted. DESCRIPTION OF SYMBOLS 1... Heat roller (fixing roller), 3... Pressure roller, 4... Pressure roller mechanism, 20... Metal pipe (core metal), 21... Elastic member, 22... Bearing ,2
5... Support lever, 30... Support shaft, 31... Compression spring (biasing body), 33... Embossed part, 34... Stepped part, 35... Positioning part, 41... ... Cap (jig), P... Image support. Applicant's agent Patent attorney Takehiko Suzue (a)
(b) Construction 5 Figure 6 Figure 7 Figure 8

Claims (4)

[Claims] (1) A fixing device that includes a fixing roller and a pressure roller mechanism that presses an image support against the fixing roller, and fixes an unfixed developer image formed on the surface of an image carrier, the pressure roller mechanism There is a pressure roller formed by covering the outer peripheral surface of a metal pipe with an elastic member, a bearing whose outer diameter part is fitted into the inner diameter part of both ends of the pressure roller, and a bearing on both ends of the pressure roller and a rotating part. A pair of support levers that are movable and have a support shaft that fits into the inner diameter of the bearing, and a biasing member that biases the support levers so that the pressure roller comes into pressure contact with the fixing roller. A fixing device characterized by: (2) The fixing device according to claim 1, wherein the metal pipe of the pressure roller is provided with a positioning portion for regulating the insertion depth of the bearing. (3) The fixing device according to claim 1, wherein the fixing roller is a heat roller. (4) The fixing device according to claim 1, wherein the biasing member is a compression spring.