JPS5924049Y2 - Copy machine cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forced air cooling device for an electrostatic or diazo copying machine, and more particularly to a structure for driving a fan.

Electrostatic copiers have several sources of heat generation.

For example, an electrostatic copying machine that uses a dry development method is equipped with a heat fixing device that includes a heat roller because it uses a toner made of thermoplastic resin. In order to achieve this, it is energized not only during copying operations but also during copying standby to maintain a temperature at which thermal fixing can be performed.

Also, during copying operations, a light source lamp that generates a large amount of heat is turned on.

Therefore, there is a risk that the temperature of various parts of the copying machine may rise undesirably due to heat generation sources such as the heat fixing device and the light source lamp, and a cooling device is required to prevent this.

In the prior art, the fan motor that rotates the fan is driven at a relatively low speed during copying standby to prevent the temperature inside the machine from rising and to prevent the heat fixing device from becoming too cold.
However, during copying operations that generate a large amount of heat, the cooling air volume is increased by driving at a relatively high speed.

In another prior art, blower assemblies each comprising a fan and a fan motor are individually mounted near a heat fixing device and a light source lamp, and the blower assembly near the light source lamp is energized only during copying operations. Ru.

These prior art techniques require a complicated electric circuit to appropriately control low-speed rotation and high-speed rotation of the fan motor.

In still another prior art, a main motor for performing a copying operation is constantly driven, a fan is constantly rotated by the main motor, and the rotational force of the main motor is transmitted to a conveyance roller or the like during a copying operation.

Since the main motor consumes a relatively large amount of power, using the main motor to rotate the fan even when copying is on standby wastes a lot of power and also generates a lot of noise.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and its main purpose is to provide a cooling device for a copying machine with a simple configuration. A cooling device for a copying machine including a main motor that is energized only to control copying operations, a fan for cooling the inside of the copying machine, a rotating shaft fixed to the fan,
a fan motor having the same rotational direction as the output shaft rotational direction of the main motor, a load rotation speed of the fan being lower than the output shaft rotational speed of the main motor, and energized at least during copy standby; A drive configured to transmit rotational driving force from the main motor to the fan when the main motor is energized, and to cut off transmission of power between the main motor and the fan when the main motor is not energized. A cooling device for a copying machine is provided, which includes a power transmitting means and is characterized in that the no-load speeds of a main motor and a fan motor are approximately equal.

An electrostatic copying machine to which the present invention is applied will be explained with reference to FIG.

Above the body 1 is a movable frame 3 having a transparent plate on which a document 2 is placed.

The moving frame 3 is provided with a holding plate 4 for pressing the original 2 onto the transparent plate.

The moving frame 3 is supported on the upper part of the fuselage so that it can be horizontally reciprocated.

Inside the body 1, there are provided a supply reel 6 on which a roll of photosensitive copy paper 5 is fitted, a copy paper cutting device 7, a charging device 8, a copy paper exposure section 9, a magnetic brush developing device 10, and a heat fixing device 11.
A copy paper transport path 12 is provided which includes the following in this order.

Above the supply reel 6 and above the copy paper cutting device 7, there is provided a driven paper feed roller 13 with a paper feed clutch which is activated at the start of a copying operation.

The copy paper cutting device 7 cuts between the fixed blade 14 and the rotary blade 15, and the rotary blade 15 is rotated by the operation of a cutter solenoid (not shown), thereby passing between the fixed blade 14 and the rotary blade 15. The rolled copy paper 5 is cut.

At this time, the rolled copy paper 5 is cut into a length corresponding to the length of the original document 2 by a conventionally known mechanism (not shown).

The charging device 8 includes a shield case 18 provided opposite to each other across the copy paper transport path 12 between the drive roller pair 16 and 17, and a thin wire corona discharge electrode 19 installed within the shield case 18. , which imparts a uniform electrostatic charge onto the photoconductive layer of the copy paper 5.

The copy paper exposure section 9 is separated from a transparent plate 21 and a guide plate 22 provided between the drive roller pair 17 and 20.

An optical system 23 that optically connects the copy paper exposure section 9 and the transparent plate of the moving frame 3 and forms an image of the original 2 onto the copy paper 5 is fixedly provided inside the body 1.

The optical system 23 includes a light source lamp 24, a reflective wall 25, a reflective mirror 26, an in-mirror lens 27, a reflective mirror 28, and the like, and has an exposure aperture 29 above the reflective wall 25 for scanning the original image. is formed.

Exposure opening 29 of the original 2 placed on the transparent plate of the moving frame 3
The movement above and the movement of the exposure section 9 of the copy paper 5 below the transparent plate 21 are performed 7 in synchronization, and the image of the original 2 is reflected by the reflecting mirror 26.
, an image is formed on the photoconductive layer of the charged copy paper 5 through the in-mirror lens 27, the reflecting mirror 28, and the transparent plate 21, and an electrostatic latent image corresponding to the image of the original 2 is formed on the copy paper 5. be done.

A guide plate 51 is provided on the lower side of the drive roller pair 20,
A magnetic brush developing device 10 is arranged below the guide plate 51.

This magnetic brush developing device 10 includes a cylindrical developer holding member 31 that magnetically holds powdered toner 30 on its surface, and a developer holding member 31 that accommodates replenishment toner 30 and holds the toner 30 from an opening provided in a side wall. It is removed from the toner replenisher 32 that supplies the toner to the member 31.

A guide roller 33 for guiding the copy paper 5 is provided below the developer holding member 31.
3 and the developer holding member 31, a minute gap is formed to allow the copy paper 5 to pass therethrough.

The copy paper 5 on which the electrostatic latent image is formed passes between the developer holding member 31 and the guide roller 33, and the electrostatic latent image on the copy paper 5 is developed.

Further downstream of the developing device 10, a heat fixing device 11 is provided.

The heat fixing device 11 includes heat rollers 3 each having a built-in heater.
When the developed copy paper 5 passes between these rollers 34 and 35, the toner 30 is heated and pressed, and the toner image is fixed.

A discharge roller 36 is provided on the downstream side of the heat fixing device 11,
The copy paper 5 on which the image has been fixed is discharged onto the copy receiving plate 37.

A cooling device 38 is provided to prevent parts of the body 1 from being heated by heat generated from the heat fixing device 11, the light source lamp 24, and the like.

The cooling device 38 includes a cross-flow fan 39, guide walls 40, 41, etc., and sucks air from an intake hole 42 provided at the bottom of the aircraft body 1 and other gaps by the rotation of the cross-flow fan 39, thereby cooling the inside of the aircraft. The heated air is discharged from the exhaust hole 44 to the outside through a ventilation hole provided in the partition wall 43 or the like inside the body 1.

FIG. 2 is a simplified perspective view of one embodiment of the present invention.

As is known, when the power switch 45 is turned on, the fan motor 46 is energized, and the heaters built into the heat roller 34 and pressure roller 35 of the heat fixing device 11 are energized, and the heat roller surface temperature control mechanism ( When the surface temperature of the heat roller 34 rises to a predetermined temperature by a mechanism (not shown), the machine body 1 enters a copy standby state.

When the print button 47 is pressed, the relay 48 is self-held.

Therefore, the main motor 49 that controls the copying operation remains energized, the copy paper 5 begins to move along the copy paper transport path 12 by the power of the main motor 49, the light source lamp 24 lights up, and the moving frame 3 is moved. Ru.

When the copying operation is completed, the microswitch 50 (see FIG. 2) detects the completion of the copying operation and interrupts the circuit, thereby releasing the self-holding of the relay 48 and deenergizing the main motor 49.

Such operating sequences are known to those skilled in the art.

As mentioned above, the main motor 49 is a capacitor motor having a rated output sufficient to control the copying operation, and its rotational speed is approximately the same under load and under no load, for example, about 330 rpm.

During the copying operation, the output of the main motor 49 is transmitted from the gear reducer 52 via the output shaft 53 of the gear reducer 52.

FIG. 3 shows a cutaway longitudinal section of a portion of the cross flow fan 39. As shown in FIG.

Referring to FIGS. 2 and 3, the fan motor 46 is an induction motor having a dark coil and has a rotational speed approximately equal to that of the main motor 49 when no load is applied (for example, 3300 rpm).
rpm), and the load rotation speed when rotating the cross flow fan 39 is low, for example about 100 Orr.
It has characteristics such as pm.

The output shaft 54 of the fan motor 46 is the cross flow fan 3
A set screw 5 is attached to a boss 56 formed on one end plate 55 of 9.
Fixed by 7.

A boss 59 provided on the other end plate 58 of the crossflow fan 39 is connected to an output shaft 61 of the main motor 49 via a one-way clutch 60.

The one-way clutch 60 is connected to the output shaft 61 of the main motor 49.
Only when the rotational speed of the crossflow fan 39 is higher than the rotational speed of the fan motor 46, the power of the main motor 49 is transmitted to the three crossflow fans through the boss 59.

Therefore, the rotation direction (arrow 62) of the output shaft 54 of the fan motor 46 and the output shaft 61 of the main motor 49 is the same.

FIG. 4 shows part of a cross section of a one-way clutch 60, which is known per se.

The outer ring 63 is fixed to the boss 59.

The output shaft 61 of the main motor 49 is disposed on the inner periphery of the outer ring 63.
A large number of inclined surfaces 64 that narrow in the direction of rotation (arrow 62) are formed at intervals in the circumferential direction.

A cylindrical roller 65 is interposed between each inclined surface 64 and the outer peripheral surface of the output shaft 61.

These rollers 65 are given elastic force in the rotational direction 62 of the output shaft 61 by spring pieces 67 provided on the retainer 66 .

Regarding the operation, during copy standby, the fan motor 46 is energized and the main motor 49 is not energized.

The fan motor 46 generates a slip by driving the cross flow fan 39 and rotates at a relatively low speed.

Therefore, the heater of the heat fixing device 11 prevents the temperature inside the copying machine from rising abnormally.

In FIG. 4a showing the standby state of the one-way clutch 60, the cross flow fan 39 and the boss 59 are shown at the arrow mark 6.
Since the output shaft 61 of the main motor 49 is stopped, the rollers 65 are located on the expanding side of the inclined surface 64 (clockwise in FIG. 4a).

Therefore, the rotational force of the boss 59 is not transmitted to the output shaft 61 of the main motor 49.

During a copying operation, not only the fan motor 46 but also the main motor 49 is energized.

The slippage of the main motor 49 under load is small, and its load rotational speed is higher than that of the fan motor, as described above.

Therefore, in FIG. 4, which shows the state of the one-way clutch 60 during the copying operation, the spring pieces 67 supported by the retainer 66 are shown.
The roller 65 is pushed in the rotational direction 62 by the elastic force.

Therefore, the rollers 65 bite between the outer peripheral surface of the output shaft 61 of the main motor 49 and the inclined surface 64, and power is transmitted from the output shaft 61 to the outer ring 63.

As a result, the power of the main motor 49 rotates the boss 59 and therefore the crossflow fan 39 at a relatively high speed, and the amount of cooling air is increased compared to when copying is on standby.

Therefore, a large amount of heat from the light source lamp 24 that is turned on during a copying operation is sufficiently radiated to the outside, and the temperature inside the copying machine is prevented from rising.

At this time, the output shaft 54 of the fan motor 46 is rotated by the main motor 49 at a speed close to the no-load rotation speed, and slippage is reduced, so that the power consumption of the fan motor 46 is advantageously reduced.

In place of the one-way clutch 60 shown in the fourth figure, a one-way clutch 68 shown in the fifth figure may be used.

In this one-way clutch 68, a driven shaft 69 is fixed to the boss 59 of the cross flow fan 39, and this driven shaft 69 has the same diameter as the output shaft 61 of the main motor 49.
are on the same axis.

A spring 70 having an inner diameter slightly smaller than that of the shaft 61, 69 is fitted to the output shaft 61 and the driven shaft 69, straddling both ends adjacent to them.

The winding direction of the spring 70 is opposite to the rotation direction of the output shaft 61.

During copy standby, only the fan motor 46 is energized, so the driven shaft 69 rotates in the direction of arrow 62, and the spring 70 releases the tightening force on the shafts 61 and 69, causing an output from the driven shaft 69. No power is transmitted to the shaft 61.

When the output shaft 61 rotates at a higher speed than the driven shaft 69 during a copying operation, the spring 70 tightens the shaft 61.69 and transmits torque from the output shaft 61 to the driven shaft 69, thereby causing the crossflow fan 39 to rotate at a higher speed. Rotate.

As yet another embodiment of the present invention, the one-way clutch 60, 68 described above may be replaced with a conventional one-way ratchet clutch that transmits power by hooking a pawl onto a ratchet wheel.

These one-way clutches are small and simple in structure;
It is suitable for copying machines because there is no failure.

Also, instead of these one-way clutches, the main motor 4
9 is operated at high speed, the torque of the main motor is transmitted to the cross flow fan 39, and when the main motor 49 is at rest, the torque from the fan motor 46 is transmitted to the cross flow fan 3 without transmitting the torque from the fan motor 46 to the main motor 49.
It may be a centrifugal clutch that transmits the signal to 9.

Furthermore, the main motor 49 and the cross flow fan 3
9, the electromagnetic clutch is connected at the same time as the main motor 49 is energized, and the torque of the main motor 49 is transmitted to the cross flow fan 39.
When the main motor 49 is at rest, power may not be transmitted between the main motor 49 and the fan.

Such a driving force transmission means is also included in the spirit of the present invention.

Other fans such as centrifugal or axial fans may be used in place of the cross-flow fan 39.

As another embodiment of the present invention, the electric circuit may be configured such that the fan motor is energized only when copying is on standby and is deenergized during copying operations.

Main motor 49 and fan motor 46 may be DC motors.

It is pointed out that the present invention can be broadly implemented in conjunction with other electrostatic and diazo type copiers, where more heat is generated during copying operations than when copying is on standby.

As described above, the present invention uses a simple structure to transmit a part of the power of the main motor, which is energized only during copying operations, to the fan using the driving force transmission means and rotate the fan at high speed. The fan can be switched between high and low speeds, is easy to maintain, and is realized at low cost.

[Brief explanation of drawings]

FIG. 1 is a simplified sectional view of an electrostatic copying machine including an embodiment of the present invention, FIG. 2 is a simplified perspective view of an embodiment of the present invention, and FIG. 3 is a cross-flow fan 39. FIG. 4 is a cross-sectional view of a portion of the one-way clutch 60 taken along section line IV-IV in FIG. 3, and FIG. 5 is a partially cutaway longitudinal sectional view, and FIG. 6 is a front view of a one-way clutch 68. FIG. 1... Aircraft, 2... Manuscript, 3...
...Moving frame, 5... Copy paper, 7... Copy paper cutting device, 8... Charging device, 9...
・Copy paper exposure section, 10...Developing device, 11...
...Heat fixing device, 24...Light source lamp, 3
4... Heat roller, 35... Pressure roller,
38... Cooling device, 39... Cross flow fan, 40.41... Guide wall, 42...
...Intake hole, 44...Exhaust hole, 46...
...Fan motor, 49...Main motor,
54.61...Output shaft, 59...Boss, 60°68...One-way clutch, 62...
···Direction of rotation.

Claims (2)

[Scope of utility model registration request] (1) A cooling device for a copying machine including a main motor that is energized only during a copying operation and controls the copying operation, comprising: a fan that cools the interior of the copying machine; a rotating shaft fixed to the fan; a fan motor that has the same rotational direction as the rotational direction of the output shaft of the motor, the load rotational speed of the fan is lower than the rotational speed of the output shaft of the main motor, and is energized at least during copy standby; A driving force configured to transmit rotational driving force from the main motor to the fan when the main motor is energized, and to cut off transmission of power between the main motor and the fan when the main motor is not energized. 1. A cooling device for a copying machine, comprising a transmission means, wherein a main motor and a fan motor have substantially the same no-load speed. (2) The fan motor is energized even during a copying operation, and the main motor and the fan motor are induction motors.
A cooling device for a copying machine according to item 1).