JPS61204667A - Oil coater - Google Patents

Abstract

PURPOSE:To prevent oil from pooling by coating a fixing roll with the oil through an intermediate member when the intermediate member is at an abutting position. CONSTITUTION:The switch SW of the solenoid 10 of an oil coater is operated associatively with the power switch of a copying machine and turns off when the power switch is turned off, and an intermediate roll 8 is held at the abutting position through the operation of a tension spring. Then, the oil 4 in a storage tank 5 is supplied to the intermediate roll 8 through felt 7 from a supply port 6 and the intermediate roll 8 is driven to apply the oil to a heat roll 1. When the power switch is turned off and the switch SW is turned on, the solenoid 10 is excited to move the intermediate roll 8 to a separation position along a long-sized hole 9 and the oil coater 3 leaves the heat roll 1. The oil coater 3 coats the heat roll 1 with the oil 4 through the intermediate roll 8 when the power switch of the copying machine is on. Consequently, the oil is prevented securely from pooling between a couple of fixing rolls.

Description

TECHNICAL FIELD The present invention relates to an oil coating device that applies oil to the surface of at least one roll of a pair of fixing rolls either directly or via an intermediate roll.

BACKGROUND OF THE INVENTION In electrophotographic copying apparatuses and other recording apparatuses, fixing apparatuses are often used in which a support carrying an unfixed toner image is held and conveyed by a pair of fixing rolls and is fixed by the action of heat. This type of fixing device has problems such as adhesive substances such as toner adhering to the fixing roll and causing offset, and in order to prevent this, the above-mentioned oil application device is provided.

The conventional oil application device uses heating o-
Oil 105 from an oil tank 104 is applied to a pair of fixing rolls consisting of a felt 106 and an application roller /L/ 103.

In the oil applicator with this configuration, the application row /L'10B is always heated even when the machine is stopped for a long time.
It is in contact with 101. Therefore, there was a problem in that oil clumps were formed at the contact portions between the felt 106 and the coating o-1v10B, and between the coating CI-/L/103 and the heating row/L/101. Due to this oil clump, a large amount of oil may be applied to a part of the support, and there is a possibility that the heating roll may be deformed or damaged.

OBJECTS The present invention aims to solve the above-mentioned conventional problems and provide an oil applicator that is completely free from oil clumps.

The present invention provides means for supplying oil to the intermediate member, and a means for moving the intermediate member between a contact position where the intermediate member contacts a fixing roll to be coated and a separation position where the intermediate member is separated from the fixing roll. means, and when the intermediate member is located at the abutting position, oil is applied to the fixing roll via the intermediate member.

Embodiments in which the present invention is applied to an electrophotographic copying machine will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a heating roll equipped with a heating means such as a heater inside, and a pressure roll 2 is provided at the bottom of the heating roll 1 to be brought into pressure contact at least during fixing. This heating roller/L/1 and the pressure roller 2 constitute a fixing roller pair. Then, oil is applied to the surface of the heating roll 1 by an oil application device 3 according to the present invention in order to prevent offset due to toner or the like.

The oil application device 3 stores oil 4 and heats the oil by heating
The storage tank 5 has a width slightly longer than the width of the heating roll 1, and an elongated hole-shaped supply port 6 extending in the axial direction of the heating roll 1 is formed at the bottom of the storage tank 5. The supply port 6 has a length that is approximately the same as the maximum size width of the support 1, for example, a transfer paper 13, which is held and conveyed by a pair of fixing rolls, and is formed at a position that approximately corresponds to the position through which the transfer paper 13 passes. In addition, the storage tank 5 has a feed/l/) 7 so as to cover the supply port 6.
In this example, the felt 7 is attached to the storage tank 5 with an adhesive or the like. This felt 7 is in contact with the upper circumferential surface of an intermediate member configured as an intermediate roll 8, which will be described later. The oil/L/4 applied to the heating row) Vl is usually silicone oil, but if necessary, chlorinated modified silicone oil, fatty acid modified silicone oil, polyoxyalkylene modified silicone oil, fluffy modified silicone oil can be used. Modified silicone oils such as nitrile-modified silicone oils and nitrile-modified silicone oils may also be used.

The intermediate roll 8 is configured to follow the rotation of the heating roller/L/1, and has a long hole 9 formed in the side plate (not shown) so that its shaft 8a extends substantially horizontally.
is mated to. The intermediate roll 8 is provided with means for moving in the longitudinal direction of the elongated hole 9. The moving means in this example has a plunger 11 connected to a shaft 8a, and a solenoid 10 that moves the intermediate roller lv8 to the right in the figure when excited, and a solenoid 10 that always moves the intermediate roller /L/g to the left. It is composed of a tension spring 12 that is biased.

In this case, if the solenoid 10 is demagnetized, □
The intermediate roll 8 is held in a position where the shaft 8a is in contact with the left end of the elongated hole 9 by the action of the tension spring 12. At this time, the intermediate roll 8 is in a contact position where it is in contact with the heating roll 1 and the felt 7, respectively, and the oil 4 is applied to the heating roll 1 via the intermediate roll at the corresponding rear position. Also, solenoid 1
0 is excited, the intermediate roll 8 is held at a position where the shaft 8a is in contact with the right end of the elongated hole 9 against the action of the tension spring 12. At this time, the intermediate roll 8 is located at a separate position away from the heating roll 1 and the felt 7.

The oil applicator thus configured is turned off when the switch SW of the solenoid 10 is linked with a power switch (not shown) of the copying machine, and the power switch is turned on. At this time, as mentioned above, due to the action of the tension spring, the intermediate roll 8
is held in the abutting position.

Then, the oil 4 in the storage tank 5 is supplied from the supply port 6 through the felt 7 to the intermediate roll 8, and the intermediate roll 8 is driven and applied to the heating roll 1.

Note that depending on the type and amount of oil supplied to the intermediate roll 8, the intermediate roll 8 may slip with respect to the heating roll 1. In such a case, if the pressing force of the storage tank 5 to the intermediate roll 8 is Po, and the pressing force of the intermediate low/I/8 to the heating roll l is P2, then the intermediate low/I/8 is adjusted so that Pl<P2. and/or it is expedient to provide the storage tank with suitable pressing means.

Next, when the power switch is turned off and the switch SW is turned on, the solenoid 10 is energized and the intermediate low
8 moves along the elongated hole 9 to the above-mentioned separated position. When the intermediate row/I/8 moves to the separated position, the oil application device 3 separates from the heating row/I/1. In addition, felt 7,
The widths of the intermediate roll 8 and the fixing row/L/1 may be set as appropriate, but for example, as shown in FIG. There is little oil unevenness over the entire width of the heating roll 1, which is advantageous.

In the oil applicator 3 thus configured, the oil level 4 is maintained at the intermediate level cff- only while the power switch of the copying machine is ON.
/l/8 to the heating roll l. Therefore, the intermediate o-)v8 will not be in contact with the heating roni/L/1 for a long time, and oil clumps can be reliably prevented. The switching between the supply position and the separation position of the intermediate roller Jv8 is 1, for example, so that the intermediate roller 8 is located at the supply position only while a copying operation is being performed, and furthermore, while the fixing roll pair is holding the transfer paper. May be controlled.

In this way, oil clumps can be eliminated, but in the case of the above embodiment, when the intermediate low/L/8 is located at the separated position, oil/v4 may drip through the felt 7 depending on the type and viscosity of the oil.

Therefore, in the present invention, as shown in FIG.
A prevention plate 27 is connected to the shaft 28a of the shaft 28a via an arm 26. In this case, the prevention plate 27 moves to the lower part of the storage tank 25 when the intermediate low/v28 moves to the separated position.

According to the oil applicator 23 configured in this way, heating low)
A storage tank 25 is arranged above the v21, and even if oil drips, it is blocked by a prevention plate 27, and the oil is heated to low/L/21.
It is advantageous because it does not stick to the surface.

FIG. 3 shows another embodiment of the invention, in which two intermediate rolls 88. (9 is provided.

Usually, the intermediate low/L'88e39 is the intermediate region, that is, the heating roll 1 is placed at the intermediate low/l'3
8.39 are held in a position where none of them touch. Here, when a copy command is issued, an intermediate roll having a width approximately corresponding to the size of the transfer paper at that time is selected and brought into contact with the heating roll 1.

For example, if the intermediate row/v38 is approximately the same width as A4 size and A4 size transfer paper is used, the intermediate row/l
/88 comes into contact with the heating roll 1.

With this configuration, the amount of oil applied is the same size as the transfer paper, which is advantageous because there is no unnecessary oil application.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, the driving source of the means for moving the intermediate roll is not limited to a solenoid, but may be a motor, and the driving source may be configured to move the intermediate roll via a link or a cam. In addition, among felts, the liquid-absorbing member is preferably one that allows oil to easily pass through, such as Cornex or Nomex (both are trade names), but cloth, non-woven fabric, etc. may also be used depending on the type and/or viscosity of the oil. .

Furthermore, the oil application device may be provided on the pressure roll side as well, if necessary.

Although the above embodiment has been described as an oil applicator used in a fixing device of a copying machine, it is of course possible to use it in a fixing device of not only a copying machine but also a facsimile and other recording devices.

Effects According to the above-described configuration, oil clumps on the pair of fixing rolls can be reliably prevented, and therefore, there is no fear of deformation or damage to the fixing roll.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, FIGS. 2 and 3 are explanatory diagrams showing embodiments of each side of the present invention, and FIG. 4 is a preferred example of each component of the present invention. FIG. 5 is an explanatory diagram of a conventional oil application device. 1... Heating low/L/2... Pressure roll 3... Oil applicator 4... Oil 5... Storage tank
6... Supply lower... Felt 1
0... Solenoid Figure 1 Figure 2

Claims (1)

[Claims] (1) When a support carrying an unfixed toner image is held and conveyed, an intermediate member is placed on the surface of at least one of a pair of fixing rolls that fixes the toner image on the support by the action of heat. In the oil coating device, the oil coating device includes a means for supplying oil to the intermediate member, a contact position where the intermediate member contacts a fixing roll to be coated, and a separation position where the intermediate member is separated from the fixing roll. an oil applying device that moves between the fixing roll and the fixing roll, and when the intermediate member is located at the contact position, oil is applied to the fixing roll via the intermediate member.