JPS5841542Y2 - Pressure roller cooling device of heat fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for cooling a pressure roller of a heat fixing device used in an electrophotographic copying machine.

Conventionally, this type of heat fixing device has a structure in which a pressure roller is pressed against a heating roller to form a nip, and a transfer paper having a toner image transferred thereto is passed through the nip portion to fix the image.

Since the pressure roller must form a predetermined nip between the heating roller and the roller, it is made of an elastic material such as rubber, but it must be cooled to prevent deterioration and deformation of the material due to heat. be.

Also, if the width of the transfer paper is smaller than the specified size, the temperature at the edge where the transfer paper does not come in contact with and pass through may become high enough to deform (extend the diameter, etc.) compared to other parts. These ends especially need to be cooled.

, these things are described, for example, in Japanese Patent Application Laid-open No. 48-7
It is described in Publication No. 4235.

Therefore, a cooling device has been proposed in which a cooling mechanism connected to a blower is disposed opposite to a heating roller, and the hot air on the surface of the heating roller is sucked and discharged.

However, this structure has the disadvantage that the air sucked by the blower is discharged into the atmosphere, which is wasteful.

The present invention was devised in view of the above circumstances, and its purpose is to provide a pressure roller cooling device for a heat fixing device in which suction air for cooling can be effectively used as an auxiliary means for the transfer paper peeling mechanism of the heating roller. The goal is to provide the following.

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

FIG. 1 is a schematic explanatory diagram showing the entirety of the present invention, in which a pressure roller 2 is pressed against a heating roller 1 to form a nip portion 3;
It has a structure in which a transfer paper 5 carrying a toner image 4 is passed through the nip portion 3 to be heated and fixed.

Reference numeral 6 denotes a cooling mechanism, in which three suction tubes 8 are fixed in the axial direction of the pressure roll 2 in a cover frame T disposed close to opposite to the pressure roller 2, and one end of each suction tube 8 is connected to a cylinder. The suction pipe 8 is connected to the suction port 12 of the blower 11 through the body 9 and the hose 10, and the other end is closed. The holes 13 are densely formed at one end in the axial direction.

This is to prevent this portion from becoming hotter than other portions when the size of the transfer paper 5 (paper) is small.

14 is a transfer paper peeling mechanism, in which a heating roller 1 has a peeling claw 1;
5 are in contact with each other.

The peeling claw 15 is rotatably fitted onto a shaft 17 fixed to a support member 16, and a spring 18 is provided between the support member 16 and the peeling claw 15, so that the peeling claw 15 is lightly pressed against the circumferential surface of the heating roller 1. It is urged to rotate in the direction of

The peeling claw 15 is provided with a groove 19 which is open at the pointed end 15a, and the groove 19 is in open communication with the shaft hole 20 of the shaft 17 via the hole 21, and the shaft hole 20 is connected to the hose 22.
It communicates with the discharge port 23 of the blower 11 through.

Thus, the high temperature air on the circumferential surface of the pressure roller 2 is sucked by the blower 11 from the suction port 13 of the suction tube 8, through the suction tube 8, the cylinder 9, and the hose 10, so that the pressure roller 2 can be cooled.

Further, the suction air of the blower 11 is discharged and ejected from the hose 22, the shaft hole 20, the hole 2'1, and the groove 19 to the pointed end 15a through the discharge port 23.

Therefore, the transfer paper 5 that has adhered to the heating roller 1 after being subjected to the fixing action is subjected to the peeling action by the peeling claw 15 and is reliably peeled off by the air jet.

Incidentally, part of the suction air may be discharged to the atmosphere, or all of the suction air may be discharged to the peeling claw 15.

Since the present invention is configured as described above, the suction air of the cooling mechanism 6 of the pressure roller 2 can be effectively used as a peeling assisting means of the transfer paper peeling mechanism 14.

Therefore, pressure roller 2f! : Not only can it be cooled, but also the transfer paper 5 can be reliably peeled off from the heating roller 1 without providing a special air jet source.

In addition, since the suction port 12 of the blower 11 is connected and communicated with the cooling mechanism 6, and the discharge port 23 is connected and communicated with the air jetting portion of the peeling claw 15, by operating the blower 11, the pressure roller 2 is cooled and peeled off. Air can be ejected from the claws 15 at the same time, and only one blower 11 needs to be controlled, which simplifies the control of the cooling mechanism 6 and the peeling mechanism 14, and also allows the blower 11 to be used for both purposes, reducing costs. becomes.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a general schematic explanatory diagram, FIG. 2 is a sectional view taken along the line ■-■, FIG. 3 is a detailed plan view of four parts, and FIG. It is a sectional view taken along the line ■-■. 1 is a heating roller, 2 is a pressure roller, 5 is a transfer paper, 6 is a cooling mechanism, 11 is a blower, 14 is a transfer paper peeling mechanism, 15 is a peeling knife

Claims (1)

[Scope of utility model registration request] In a heat fixing device formed by pressing a heating roller 1 and a pressure roller 2, a cooling mechanism 6 for sucking high-temperature air around the circumferential surface of the pressure roller 2 is disposed in the vicinity of the pressure roller 2, The heating roller 1 includes a transfer paper peeling mechanism 1 equipped with a peeling claw 15 having an air jet portion on the circumferential surface of the heating roller 1.
4, the suction port 12 of the blower 11 is connected and communicated with the cooling mechanism 6, and the discharge port 23 is connected and communicated with the air jetting portion of the peeling claw 15. Device.