JP2638670B2 - Electromagnet for driving the damper in the air feeding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention is provided in a paper feeding device of an air feeding type in an image forming apparatus such as an electrophotographic copying machine, and drives a damper to open and close an air passage. The present invention relates to a solenoid type electromagnet.

(Prior Art) As a paper feeding device used in an image forming apparatus such as an electrophotographic copying machine, for example, an air feeding system disclosed in JP-A-58-78932 is known. . A paper feeder adopting the air paper feed system separates the topmost sheet in the tray one by one from other sheets and sequentially feeds the sheets in a predetermined direction by a combination of air intake and air supply. In the paper feeder, the air passage is switched between an open state and a closed state by a damper in accordance with the timing of intake and supply. Normally, a solenoid type electromagnet is used for switching control of the damper.

As shown in FIG. 7, for example, the electromagnet includes a plunger 51 having one end connected to a damper via a wire 40.
And a solenoid 52 inserted into the shaft center so that one end of the plunger 51 extends. The damper is, for example, urged to close the air passage, and the urging force pulls the plunger 51 via the wire 40. The solenoid 52 has a built-in coil 53 for moving the plunger 51 in the axial direction against the traction force.
Is energized. As a result, the plunger 51 is pulled into the solenoid 52, and the air passage is opened.

The plunger 51 is usually fitted with a buffer ring 54 made of an elastic material such as rubber.
54 allows the plunger 51 to stop at a predetermined position.

When the energization of the coil 53 is stopped, the plunger 51 is pulled through the wire 40, and the one end face of the plunger 51 is placed on the buffer plate 55 made of an elastic material such as rubber held by the solenoid 52. The plunger 51 is pulled out of the solenoid 52 until it comes into contact.

(Problems to be Solved by the Invention) An air-feeding type sheet feeding device using such an electromagnet as a damper driving device usually has a high-speed electrophotographic copying machine having a copying capacity of 60 sheets / min or more. Used for For this reason, paper dust,
Many foreign substances such as toner are scattered. When the sheet feeding device operates in such a state, foreign matter is diffused by an air current used for air feeding, and the electromagnet in the sheet feeding device is used in a state where the foreign matter is floating. For this reason, in an electromagnet in a state where one end of the plunger 51 extends from the solenoid 52, the solenoid in which the plunger 51 and the plunger 51 are inserted.
Foreign matter may enter into the gap with 52. When foreign matter enters between the plunger 51 and the solenoid 52, the resistance of the plunger 51 during operation increases, and in the worst case, the plunger 51 becomes inoperable.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to prevent foreign matter from entering the gap between the plunger and the solenoid even when the plunger is driven while the foreign matter is floating. To provide a damper driving electromagnet.

(Problems to be Solved by the Invention) The damper driving electromagnet in the air sheet feeding apparatus of the present invention separates the stacked sheets by air, and sucks and feeds the top sheet by air. An electromagnet for driving a damper for opening and closing an air passage, the plunger having one end connected to the damper urged in a predetermined direction, and one end of the plunger from one end. The plunger is inserted into the shaft center portion so that the portion protrudes, and a seating portion is formed on the other end side, and a solenoid in which the plunger is moved in the axial direction by energization is made of a flexible material, A cylindrical holding portion fitted to the outer peripheral surface of the plunger protruding from one end of the solenoid, a contact portion having a diameter larger than that of the holding portion and abutting on one end of the solenoid; The holding portion and the A connecting portion formed between the abutting portions and deforming by movement of the plunger, extending over an outer peripheral surface of the plunger protruding from the solenoid and around a portion of the solenoid where the plunger protrudes; When the plunger moves to the solenoid side, the holding portion contacts one end of the solenoid to stop the plunger, and in this state, the other end of the plunger, It is configured such that a slight gap is formed between the solenoid and the seating portion, thereby achieving the above object.

(Operation) According to the above configuration, the outer peripheral surface of the plunger projecting from the solenoid and the periphery of the protruding portion of the plunger in the solenoid are sealed by the cover. In this cover, since the connecting portion expands and contracts and deforms following the operation of the plunger, the respective sealed states are maintained.
Therefore, there is no possibility that foreign matters such as paper dust and toner enter the gap between the plunger and the solenoid.

In addition, according to the above configuration, when the plunger moves to the solenoid side, the holding portion of the cover made of a flexible material, that is, a material having high elasticity, comes into contact with one end side of the solenoid, whereby the plunger moves. Is stopped. Therefore,
The holding portion functions as a stopper member for the plunger.

Here, when the plunger is stopped, a slight gap is formed between the other end of the plunger and the seat of the solenoid. Therefore, there is no possibility that the two will come into contact with each other violently and generate an impact sound. In addition, one of them does not wear and its life is not shortened.

On the other hand, the contact between one end of the solenoid and the holding portion absorbs the impact at the time of the contact because the holding portion is formed of a material having a high elasticity. Therefore, no impact noise and no abrasion occur.

For this reason, according to the above configuration, when the plunger is stopped, no impact sound or wear occurs at both ends of the plunger and the solenoid, so that the damper driving electromagnet for the silent and long life air feeder is used. realizable.

In addition, this type of air feeding apparatus is provided in an image forming apparatus such as a copying machine. Here, the image forming apparatus is generally installed in an environment where quietness is required, such as an office. Therefore, the installation environment of the image forming apparatus can be improved according to the damper driving electromagnet for the air feeding device having the above configuration.

(Example) Hereinafter, the present invention will be described with reference to examples.

INDUSTRIAL APPLICABILITY The electromagnet of the present invention is used as a driving device of a damper used for opening and closing an air passage in an air feeding type paper feeding device used in an electrophotographic copying machine. As shown in FIG. 4, a paper feeding device of an air feeding type in an electrophotographic copying machine is a paper feeding means for sucking and sending out the top sheet 11 among the sheets 11, 11,... 20a
And a sheet separating means 20b for separating the uppermost sheet 11 from the other sheets 11, 11,... So that the uppermost sheet 11 is sucked by the sheet sending means 20a.

The paper feeding means 20a includes an endless porous belt 22 having a large number of through-holes wound between a pair of rollers 21 and 21.
And an intake box 23 disposed inside the porous belt 22. The intake box 23 has an internal air passage 23a that is depressurized by a vacuum pump (not shown), and has a suction port 23b at a lower portion facing the inner surface of the porous belt 22. The paper separating means 20b is provided in an air supply box disposed in the paper feeding direction of the tray 10 and below the porous belt 22.
With 24. In the air supply box 24, an internal air passage 24a is connected to a blower (not shown), a floating nozzle 24b is provided on the tray 10 side portion, and a separating nozzle 24c is provided on the upper portion. I have.

In the paper feeding device, when feeding paper, the vacuum pump and the blower start operating, and the air passage 23 of the intake box 23 is opened.
a and the air passage 24a of the air supply box 24 are opened. Thus, outside air is sucked into the air passage 23a from the suction port 23b through the many through holes of the porous belt 22, and the floating nozzle 24b and the separation nozzle 24c of the air supply box 24 are provided.
Air is blown out from each. The air blown out from the levitation nozzle 24b is applied to the paper stacked in the tray 10.
Several sheets of paper 11,11 including the topmost sheet 11 of 11,11 ...
… Emerge. These sheets 11, 11,... Are blown by the air blown out from the separation nozzle 24c, and the lower sheets 11, 11,.
, And is adsorbed on the outer peripheral surface of the porous belt 22. When the top sheet 11 is adsorbed on the porous belt 22,
The side of the paper 11 on the paper feed side is in a wavy state protruding upward, and a gap is created between the paper 11 and the second paper 11. In such a state, the air blown out from the separation nozzle 24c enters the gap, so that the gap between the uppermost sheet 11 and the second sheet 11 further widens, and the uppermost sheet 11 becomes two sheets. Are completely separated from the papers 11, 11,. In this way, when only the uppermost sheet is attracted to the porous belt 22, the porous belt 22 is driven, and the uppermost sheet 11 is moved in the sheet feeding direction by the porous belt 22. .

The paper feeder is provided with an opening / closing mechanism for switching the air passage 23a between an open state and a closed state in order to turn on / off a sheet suction operation by the suction box 23. Similarly, an opening / closing mechanism for switching the air passage 24a between an open state and a closed state is provided to turn on / off the sheet separating operation by the air supply box 24. These opening and closing mechanisms are shown in FIG. 5 and FIG.

The opening / closing mechanism of the intake box 23 includes an internal air passage 23a.
And a rotary damper 25 disposed therein. The damper 25 has a damper plate 2 large enough to close the air passage 23a.
5a, a rotating shaft 25b for rotatably pointing the damper plate 25a into the air passage 23a, and a vertical pulley 25c attached to one end of the rotating shaft 25b. A wire 40 is wound around the pulley 25c. One end of the wire 40 is connected to a tension spring 26 disposed on the upstream side of the air passage 23a, and the other end of the wire 40 is below the intake box 23 and is connected to the air supply box 24. It is connected to the electromagnet 30 of the present invention, which is disposed on the side.

The opening and closing mechanism in the air supply box 24 also has an internal air passage 24a.
And a rotary damper 27 disposed therein. The damper 27 also has a damper plate 27a capable of closing the air passage 24a, a rotating shaft 27b for rotating the damper plate 27a, and a pulley 27c attached to an end of the rotating shaft 27b. A wire 40 is wound around the pulley 27c. The wire 40
One end is pulled by a tension spring 28 disposed on the air supply direction upstream side of the air supply box 24, and the other end is provided below the side of the air supply box 24. Is connected to the electromagnet 30 of the present invention, which is disposed in the first embodiment.

Each electromagnet 30 has the same structure,
As shown in the figure, it has a solenoid 33 and a cylindrical plunger 31 disposed in the solenoid 33.

In the solenoid 33, a coil 33b is wound around a bobbin 33a, and the bobbin 33a and the coil 33b are accommodated in a yoke 33c. The yoke 33c has one end face open, and the other end face is covered by a side face having a through hole 33g. The plunger 31 is attached to the bobbin 33a.
Is accommodated so as to be movable in the axial direction, and one end thereof is extended from the open end surfaces of the bobbin 33a and the yoke 33c. The open end face of the yoke 33c is covered by a lid 33d having a through hole through which the plunger 31 is inserted. The through hole of the lid 33d is sized so as not to hinder the movement of the plunger 31 in the axial direction.

An end of the plunger 31 extending from the yoke 33c has a slit 31a parallel to the axis, and a pin hole penetrating in a radial direction of the plunger 31 in a state perpendicular to the slit 31a.
31b. In the slit 31a, the wire 40
The stopper 41 attached to the end of is inserted,
The stopper 41 is separated by the split pin 32 inserted into the pin hole 31b.
It is held in the slit 31a. Accordingly, the plunger 31 is in a biased state pulled by the tension spring 26 or 28 attached to the other end of the wire 40.

The other end of the plunger 31 located inside the bobbin 33a has a tapered portion 31 whose diameter is gradually reduced toward the distal end.
has become c. The tapered portion 31c of the plunger 31
The bobbin 33a is configured to be seated on a seat portion 36 housed at an end thereof.

The seat portion 36 is held in a through hole provided in a bottom surface that covers the end surface of the yoke 333, and a portion of the bobbin 33a on the plunger 31 side is formed by a tapered surface 31c of the plunger 31.
Has a tapered surface 36a similar to the tapered surface 31c so as to fit therein. A through hole 36b is provided in the axial center of the seat 36.

A stopper 34 is attached to the outer peripheral surface of the yoke 33c in the solenoid 33. The stopper 34 extends in the direction of extension of the plunger 31 along the outer peripheral surface of the yoke 33c, and the tip of the stopper 34 is bent toward the plunger 31 so that the outer edge of the end surface of the plunger 31 is formed. And a main body 34b facing the main body. A buffer plate 34a made of an elastic material such as rubber which alleviates an impact when the end surface of the plunger 30 collides is attached to a side surface of the distal end portion of the main body portion 34b facing the end surface of the plunger 31. I have.

The tip end surface of the plunger 31 pulled by the wire 40 abuts on the buffer plate 34a, thereby preventing the plunger 31 from being pulled out of the solenoid 33. solenoid
When the coil 33b of 33 is energized, the plunger 31 is pulled into the solenoid 33 against the pulling force of the wire 40.

A cylindrical cover 35 made of a flexible material such as rubber is attached to a tip of the plunger 31 projecting from one end of the solenoid 33. As shown in FIGS. 3 (a) to 3 (c), the cover 35 has a holding portion fitted to the solenoid 33 side of the split pin 32 at the tip of the plunger 31.
35a, a thin cylindrical connecting portion 35b extending from the substantially central portion of the holding portion 35a in the axial direction toward the solenoid 33 side and having a diameter larger than that of the holding portion 35a, and further, the connecting portion 35b on the solenoid 33 side. And a cylindrical contact portion 35c thicker than the connecting portion 35b.

The holding portion 35a of the cover 35 has an inner diameter (for example, about 0.2 to 0.5 mm) slightly smaller than the outer diameter of the plunger 31, and is held in a sealed state in close contact with the outer peripheral surface of the plunger 31. . The holding portion 35a is in contact with the split pin 32, and the holding portion 35a is pressed by the split pin 32 to prevent the holding portion 35a from coming off. Also, the contact portion 35c on the solenoid 33 side
Is in a sealed state in contact with the lid 33d of the solenoid 33. When the plunger 31 is pulled into the solenoid 33, the holding portion 35a moves integrally with the plunger 31 and contacts the lid 33d of the solenoid 33. At this time, the thin connecting portion 35b is
Deformation follows the movement of the holding portion 35a that moves together with 1. The axial length of the holding portion 35a is
When the plunger 31 is pulled, the tapered surface 31c of the end in the solenoid 33 of the plunger 31
However, it is set so as to have a slight gap with the tapered surface 36a of the seat portion 36.

The operation of the electromagnet 30 of the present invention having such a configuration is as follows. In the electromagnet 30 that controls the opening and closing of the air passage 23a in the intake box 23, when the coil 33b of the solenoid 33 is not energized, the plunger 31 is pulled out of the solenoid 33 by the wire 40 pulled by the tension spring 26. As shown in FIG. 1, the plunger 31 is in contact with the buffer plate 35a of the stopper 34. Thereby, the damper plate 25a of the damper 25 disposed in the air passage 23a keeps the inside of the air passage 23a closed. On the other hand, when the coil 33b of the solenoid 33 is energized, the plunger 31 is pulled into the solenoid 33 as shown in FIG.
Is pulled by the plunger 31.
Accordingly, the damper plate 25a of the damper 25 is rotated, and the air passage 23a is switched from the closed state to the open state. As a result, air feeding is performed by the sheet feeding device as described above.

The opening and closing control of the damper 27 disposed in the air passage 24a in the air supply box 24 is also performed by the solenoid 30 in the same manner.

Each of the electromagnets 30 is in a state where the plunger 31 extends from a cover 35 in contact with the lid 33c of the solenoid 33. The cover 35 is in a state in which a cylindrical holding portion 35a is in close contact with the outer peripheral surface of the plunger 31 and is sealed, and the abutment surrounding the plunger 31 portion of the solenoid 33 extending from the lid. The part 33c is the lid 33c
Is pressed into contact with the end face and is sealed. Moreover, a thin connecting portion 35b is provided between the contact portion 35c and the holding portion 35a.
When the paper is fed by the paper feeding device, foreign matters such as paper dust and toner floating around the electromagnet 30 may enter the solenoid 33 from the through hole of the lid 33c. Absent. Further, even when the plunger 31 is retracted into the solenoid 33, the holding portion 35
The sealing state of the outer peripheral surface of the plunger 31 is maintained while the contact part 35c is pressed against the lid 33c. Then, as the plunger 31 moves, the holding portion 35c and the contact portion 35c expand and contract, and there is no possibility that the sealing performance of the cover 35 is impaired. Therefore, the plunger 31 always operates smoothly.

Further, when the plunger 31 is pulled into the solenoid 33, the holding portion 35a of the cover 35 contracts in the axial direction, thereby absorbing the shock when the plunger 31 stops at the retracted position. The sound can be kept low.

(Effect of the Invention) The electromagnet for driving the damper in the air sheet feeding device of the present invention can be operated in a state in which the foreign matter accompanying the air feeding is floating, so that the foreign matter is present in the gap between the plunger and the solenoid. There is no risk of intrusion. Therefore, even when an electronic copying machine or the like employing an air feeding device is used for a long time,
At all times, a smooth paper feeding operation is performed.

In addition, according to the present invention, the holding portion of the cover made of a flexible material, that is, a material having a high elasticity, functions as a stopper member of the plunger. Since a slight gap is formed between the solenoid and the seating portion of the solenoid, when the plunger is stopped, no impact noise or wear occurs at both ends of the plunger and the solenoid, so that the air is quiet and has a long life. It is possible to achieve an effect that a damper driving electromagnet for a sheet feeding device can be realized.

In addition, this type of air feeding apparatus is provided in an image forming apparatus such as a copying machine, and the image forming apparatus is generally installed in an environment where quietness is required, such as an office. Therefore, according to the present invention, the installation environment of the image forming apparatus can be improved.
Such an effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an example of the electromagnet of the present invention, FIG. 2 is a longitudinal sectional view for explaining its operation, FIG. 3 (a) is a front view of a cover used for the electromagnet, FIG. Fig. 3 (b)
3 (c) is a cross-sectional view taken along line II of FIG. 3 (a), FIG. 4 is a schematic side view of a paper feeder using the electromagnet, and FIG. FIG. 6 is a front view of an air passage opening / closing mechanism in a paper device, FIG. 6 is a side view thereof, and FIG. 7 is a longitudinal sectional view of a conventional electromagnet. 23a, 24a Air passage, 25, 27 Damper, 30 Electromagnet, 31 Plunger, 33 Solenoid, 35 Cover.

Claims (1)

(57) [Claims] 1. An electromagnet for driving a damper for opening and closing an air passage, which is used for an air sheet feeding device that separates the stacked sheets by air and sucks and feeds the uppermost sheet by air. A plunger having one end connected to the damper urged in a predetermined direction, the plunger being inserted into a shaft center portion such that one end of the plunger projects from one end side, and A seat is formed at the other end, and the plunger is axially moved by energization. The solenoid is made of a flexible material, and is fitted to the outer peripheral surface of the plunger protruding from one end of the solenoid. A cylindrical holding portion, a contact portion having a diameter larger than the holding portion and being in contact with one end of the solenoid, and formed between the holding portion and the corresponding contact portion to move the plunger. Has a connecting part that is deformed by A cover that seals around an outer peripheral surface of the plunger protruding from the solenoid, and a periphery of a portion of the solenoid where the plunger protrudes, and when the plunger moves toward the solenoid, the holding portion is The plunger is stopped by abutting against one end of the solenoid, and in this state, a small gap is formed between the other end of the plunger and the seat of the solenoid. An electromagnet for driving a damper in a paper device.