JP2868554B2 - Fixing roller oil supply device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for supplying oil to a fixing roller in a fixing device such as a copying machine.

(Prior Art) In an electrophotographic copying machine or the like, a fixing device is used to fix a toner image transferred in a transfer process on transfer paper.

As shown in FIG. 4, the transfer paper P on which the toner image T is formed is conveyed by a fixing roller 1 and a pressure roller 2 which rotate while being pressed against each other, as shown in FIG. A heating / pressing type fixing device for fixing a toner image T on P is known.

Here, the fixing roller 1 is provided with a heat source 20 such as a heater.
The pressure roller 2 is pressed against the fixing roller 1 by a pressure arm 3 which is swung by a pressure spring.

In FIG. 4, the transfer paper P enters the nip (pressure contact portion) between the fixing roller 1 and the pressure roller 2 through the transfer paper carry-in path formed by the entrance guide plates 4 and 5, and the transfer paper P It is nipped and conveyed by the pressure roller 2.

Thus, the toner image T transferred in the transfer step is heated and pressed by the fixing roller 1 and is fixed on the transfer paper P.

The transfer paper P on which the toner image has been fixed is separated from the peripheral surface of the fixing roller 1 by the separation claws 21 and
Are discharged from the fixing device main body by a pair of paper discharge rollers guided and rotated in contact with each other.

By the way, the fixing roller 1 of this type of fixing device is made of a material having excellent releasability and heat resistance such as silicon rubber or Teflon in order to prevent the toner image T from being offset at the time of fixing. , Surface treatment.

Further, this type of fixing device, in particular, a fixing device in which the fixing roller 1 is a silicon rubber roller, applies silicone oil (hereinafter simply referred to as oil) as a release agent to the peripheral surface of the fixing roller 1, and It is configured to further enhance the releasability.

As shown in FIG. 4, the oil supply device for the fixing roller usually has an oil application felt 8 so that the upper end contacts the peripheral surface of the fixing roller 1 and the lower end is immersed in the oil 11 in the oil receiver 10. The oil application felt 8 is configured to suck up the oil 11 in the oil receiver 10 by capillary action and apply the oil 11 to the peripheral surface of the fixing roller 1.

Here, the oil 11 is supplied from the oil tank 111 to the oil receiver 10 by oil supply means 110 as shown in FIG.
Supplied within.

The oil supply means 110 includes a pump drive gear 13, a pump drive cam gear 14, an actuator 15, and an oil pump sleeve 1.
6, the oil hose 18, the discharge nozzle 19 and the like.

In FIG. 5, the pump driving gear 13 is
The pump driving cam gear 14 is rotated in synchronism with the rotation of.

The actuator 15 is driven in conjunction with the rotation of the pump drive cam gear 14, and the drive of the actuator 15 causes the oil pump sleeve 16 to be pumped, thereby pumping up the oil 11 in the oil tank 111.

The oil 11 thus pumped is supplied from the discharge nozzle 19 into the oil receiver 10 through the oil hose 18.

However, as described above, such an oil application device sucks up the oil 11 in the oil receiver 10 and applies the oil 11 to the peripheral surface of the fixing roller 1 due to the capillary phenomenon of the oil application felt 8. There is a limit to the speed at which the oil 11 can be sucked up.
When the fixing process is performed by rotating at a high speed of about 40 rpm or more, there is a problem that the amount of oil applied to the fixing roller 1 becomes insufficient and the speed of the fixing process cannot be increased.

Therefore, in order to solve such a problem,
As shown in FIG. 6, the oil
An oil supply method (Japanese Patent Application Laid-Open No. 59-10047) in which the oil supply amount is prevented from being insufficient even at the time of high-speed fixing by dropping the oil 11 directly, or the oil 11 supplied from the oil tank 111 is used. The oil is directly dropped at a substantially central position in the width direction of the fixing roller 1, and oil receiving portions are provided on both sides of the oil application felt 8 located on both sides of the fixing roller 1.
An oil coating device (Japanese Utility Model Laid-Open No. 63-038166) has been proposed in which a hanging portion is provided in the fixing roller 1 so that oil can be reliably supplied to the fixing roller 1 even when the fixing roller 1 is used at high speed. ing.

(Problems to be Solved by the Invention) However, in the conventional oil supply method (or apparatus), a large amount of oil 11 is deposited at the dropping portion of the oil 11, that is, at the central portion of the oil-applied felt 8 or the fixing roller 1. However, at a position distant from the dropping portion, that is, at both sides of the fixing roller 1, as before, it depends on the capillary phenomenon of the oil-applied felt 8. Tends to occur.

For this reason, in particular, a silicone rubber roller having a low mechanical strength is used as the fixing roller 1,
In the case where a toner that requires a high release property is used, there is a problem that the fixing roller 1 is damaged or an offset occurs due to the above-described phenomenon of the shortage of the oil 11.

The present invention has been made in view of the above points,
An object of the present invention is to provide a fixing roller oil supply method that can prevent the occurrence of an excessive or insufficient oil application amount in a fixing roller and improve the reliability of a fixing device.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a fixing roller having a built-in heat source for fixing a toner image on a transfer sheet by nipping and conveying the transfer sheet on which the toner image is formed. An oil-applied felt for applying oil for preventing offset of the toner image in contact with a peripheral surface of the oil-applied felt; an oil supply unit for supplying the oil to the oil-applied felt; and a part of the oil-applied felt. An oil supply device for a fixing roller having an oil receiver for immersing the oil in an oil, comprising an oil distribution weir located above an oil application site of the oil application felt, and temporarily supplying oil supplied by the oil supply means. It has an oil storage tank for blocking, and the oil blocked by the oil storage weir passes through the oil distribution weir, Oil is supplied to the oil-applied felt by substantially evenly overflowing toward the oil-applied felt of the oil-applied felt.

(Operation) According to the present invention, the oil temporarily blocked by the oil storage tank overflows from the oil distribution weir toward the oil-applied felt of the oil-applied felt, so that the oil is applied to the oil-applied felt. The oil is supplied substantially evenly.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

A feature of the present invention is that, as shown in FIG. 1, an oil storage tank 22 is provided above an oil application portion 8a of an oil application felt 8 to temporarily store the oil 11 supplied by the above-described oil supply means 110. While blocking the oil, the oil 11 blocked by the oil storage tank 22 is removed from the oil distribution weir.
Through 24, the oil application part 8a of the oil application felt 8
The oil 11 is supplied to the oil-applied felt 8 by substantially evenly overflowing toward the oil-applied felt 8.

That is, in FIG. 1, the oil 11 passes through the oil hose 18 of the oil supply means 110 as described above.
From the discharge nozzle 19, the oil is dropped and supplied onto an oil storage tank 22 provided above the oil application site 8 a of the oil application felt 8. The lower portion of the oil-applied felt 8 is immersed in the oil in the oil receiver 10.

Here, as shown in FIG. 1, the oil storage tank 22 in the present embodiment utilizes a felt presser 23 for pressing the oil application portion 8a of the oil application felt 8 against the peripheral surface of the fixing roller 1. Is formed.

As a result, a new member for forming the oil storage tank 22 is not required, and the cost and complexity are not increased.
An oil reservoir 22 can be provided.

An oil distribution weir 24 is formed in a portion of the oil storage tank 22 along the oil application portion 8a of the oil application felt 8, that is, a portion along the width direction on the peripheral surface of the fixing roller 1.

Here, the oil distribution weir 24 in this embodiment is formed by bending the end of the felt presser 23 in the width direction similarly to the oil storage tank 22, and is formed without using a new member. Have been.

The oil distribution weir 24 shown in FIG. 1 has an oil overflow portion formed by a plurality of notches 24a cut out in a V-shape.

These notches 24a allow the oil 11 blocked by the oil storage tank 22 to almost uniformly overflow toward the oil application site 8a of the oil application felt 8 from the dropping point of the oil 11 by the discharge nozzle 19. It is formed so that the number increases (the pitch decreases) as the distance increases.

That is, in this type of oil supply device, the oil 11 is not supplied so as to flow out of the discharge nozzle 19, and the oil drops from the discharge nozzle 19 in synchronization with the rotation speed of the fixing roller 1 as described above. Is done.

For this reason, as described above, the oil 11 dropped into the oil storage tank 22 is centered around the drop point,
The liquid is gradually diffused in the width direction of 22, and sequentially overflows from the notch 24a near the drop point.

Therefore, like the oil distribution weir 24, the number of the notches 24a is increased as the distance from the drop point of the oil 11 increases, so that the oil 11 from the oil distribution weir 24 is increased.
Can be averaged.

As another method of averaging the supply amount of the oil 11 from the oil distribution weir 24, the pitch of each notch 24a is equal, and as the distance from the drop point of the oil 11 increases, each notch 24a
The depth of 24a, that is, the height from the bottom of the oil storage tank 22 may be formed so as to gradually decrease, and the oil overflow amount may be adjusted so as to be substantially uniform.

Also, as is apparent here, this oil distribution weir 24
As shown in FIG. 2, the height of the upper edge portion 24b, ie, the oil storage tank, increases with distance from the drop point of the oil 11, as shown in FIG. Forming the height from the bottom of 22 gradually lower,
The oil overflow amount in the width direction may be configured to be substantially uniform.

Further, in the oil distribution weir 24 shown in FIGS. 1 and 2, an example is shown in which the oil 11 overflows through each notch 24a or the upper edge 24b. Other ways of spilling oil 11 include:
As shown in FIG. 3, a number of small holes 24c may be formed in the bottom of the oil storage tank 22 to form an oil overflow portion.

Here, as a method of equalizing the overflow amount of the oil 11 from each small hole 24c, as in the case of each notch 24a shown in FIG. Either gradually increase the density of the holes 24c, or
The diameter of 4c may be gradually increased so that the oil overflow in the width direction is substantially uniform.

As described above, according to the present invention, the oil 11 temporarily blocked by the oil storage tank 22 is
From the oil-applied felt 8 to the oil-applied area 8a of the oil-applied felt 8 so that the oil 11 does not depend on the capillary action of the oil-applied felt 8 , Are directly dripped substantially uniformly along the width direction thereof, and are supplied substantially uniformly.

(Effects of the Invention) According to the present invention, the oil distribution weir is provided above the oil application site of the oil application felt, and the oil blocked by the oil storage weir is substantially evenly directed toward the oil application site of the oil application felt. Since it overflows, it is possible to prevent the occurrence of excessive or insufficient partial oil application amount of the fixing roller with a simple configuration.For example, as a fixing roller, a silicon rubber roller having low mechanical strength can be used, Even when a toner that requires high releasability is used as a developer, it is possible to prevent damage to the fixing roller and occurrence of offset due to a shortage of oil supply amount, thereby improving the reliability of the fixing device. Can be improved.

[Brief description of the drawings]

1 is a schematic perspective view of one embodiment of the present invention, FIG. 2 is a perspective view of a main part of another embodiment of the present invention, FIG. 3 is a perspective view of a main part of still another embodiment of the present invention, FIG. 4 is a schematic sectional view of a conventional fixing device, FIG. 5 is a perspective view of oil supply means in the fixing device, and FIG. 6 is a schematic perspective view of another conventional fixing device. 1 ... fixing roller, 8 ... oil-coated felt, 8a ...
Oil application site, 11 Oil, 20 Heat source, 24 Oil distribution weir, 24a Notch, 24b Upper edge of oil distribution weir, 24c Small hole, 110 Oil supply means , 22 ... oil storage tank, P ... transfer paper, T ... toner image.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsuneo Kurotori 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References Japanese Utility Model Showa 60-176459 (JP, U) (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 13/20 G03G 15/20

Claims (1)

(57) [Claims] An oil for preventing offset of the toner image is applied in contact with a peripheral surface of a fixing roller having a built-in heat source for fixing the toner image on the transfer paper by nipping and transporting the transfer paper on which the toner image is formed. And an oil supply unit for supplying the oil to the oil-coated felt, and an oil receiver for immersing a part of the oil-coated felt in the oil. An oil distribution weir located above the oil application site of the oil application felt, and an oil storage tank for temporarily obstructing the oil supplied by the oil supply means; The oil that has flowed through the oil distribution weir almost evenly overflows toward the oil-applied area of the oil-applied felt. Oil supply device of the fixing roller, characterized in that to.