JPH01116566A - Image forming device - Google Patents

Abstract

PURPOSE:To attain miniaturization and to reduce weight by integrating a cam part with an energizing means. CONSTITUTION:A torsion bar 34 is provided to rotate centering around a point 36 deviated from the center of rotation and one end part thereof is fixed on a 1st main body part 31. The cam parts 34a and 34b which control rotation moment acting to a 2nd main body part 32 according to the opening position of the 2nd main body part 34 are integrated with the torsion bar 34. Thus, the angle E of a cam part 32a and the relation between the center of rotation 33 and the center of rotation 36 can be selected and the moment acting to the part of interval L2 becomes small, so that the deformation of the 2nd main body part 32 can be made small. Since rigidity can be made small, the reduction in weight such as molding the 2nd main body part or the reduction of reinforcing members can be attained.

Description

Detailed Description of the Invention [Field of Application in Industry A] The present invention comprises a device main body that is composed of a lower first main body portion and a second upper main body portion that are divisible, and the second main body portion is rotatably coupled to the body portion to connect the second body portion to the first body portion;
The present invention relates to an image forming apparatus whose main body portion can be opened and closed.

[Prior Art] Conventionally, image forming apparatuses in which the main body of the apparatus can be divided into two as described above have been widely used. In order to prevent accidents such as injury due to the body closing during operations such as processing, it is common to provide a biasing means for biasing the upper body portion in the opening direction. However, the upper body part contains units surrounding the photosensitive drum such as the process cartridge, an optical system, part of the transport device, drive-related units, etc., so it is quite heavy. . Therefore, the load applied to the biasing means for biasing the upper body part becomes large, and the upper body part needs to have rigidity, so the upper body part becomes larger and its weight increases. increase

[Problems to be Solved by the Invention] In order to eliminate such disadvantages, the document table, which was conventionally provided in the upper main body part, is configured to remain in the lower main body part, and the upper main body part is An image forming apparatus has been proposed that is smaller in size and has a lighter weight.

However, in such conventionally proposed image forming apparatuses, it is possible to significantly reduce the size and weight of the upper main body part, but even in such image forming apparatuses, the biasing means itself is When the upper main body part is closed, that is, when the image forming apparatus is in use, the generated load is larger than when the upper main body part is opened. Setting the means load
When the upper body part is closed, an unnecessarily large load is applied to the body part, causing deformation of the upper body part, or requiring reinforcement to prevent deformation of the upper body part. There was a problem.

The present invention is intended to solve the above-mentioned problems in an image forming apparatus of the type in which the apparatus main body is divided into a lower first main body part and an upper second main body part.

[Means for Solving the Problems] As a means for solving the above-mentioned problems, the present invention comprises a device main body consisting of a lower first main body portion and an upper second main body portion that are separable, and a second main body portion that is separable. In an image forming apparatus in which a main body part is rotatably connected to a first main body part and the second main body part can be opened and closed with respect to the first main body part, a direction in which the second main body part is opened with respect to the first main body part. a biasing means for applying a rotational moment to the first body portion, and a cam portion for controlling the rotational moment acting on the second body portion in response to an open position of the second body portion to the biasing means. The present invention provides an image forming apparatus characterized in that it is integrated. As the biasing means, a torsion bar or the like can be used.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

Before describing embodiments of the present invention, a conventional image forming apparatus will be described with reference to FIG. FIG. 4 is a perspective view showing a conventional image forming apparatus in which the main body of the apparatus is composed of a first body part on the lower side and a second main body part on the upper side. indicates a second main body portion. The second main body portion 2 is connected to the first
It is rotatably connected to the body part 1 so that the second body part 2 can be opened and closed relative to the first body part 1.

Two torsion bars 4 are provided as biasing means for applying a rotational moment in the direction of opening the second body portion 2 relative to the first body portion 1, and each torsion bar 4 is provided so as to pass through the rotation center 3. Its one end 4A is fixed to the first body 1, and the other end 4B engages with a pin 5 provided on the second body 2 to apply a rotational moment to the second body 2 in the opening direction. There is.

In such a conventional structure, when the strength of the torsion bar 4 is set to a strength that holds the second body part 2 in an open state, the torsion bar 4 further increases when the second body part 2 is closed. To be twisted, the second body part 2
The rotational moment acting on the motor becomes unnecessarily large.

In order to eliminate the above-mentioned drawbacks, in the present invention, a cam member for controlling the rotational moment acting on the second body part 2 according to the opening angle of the second body part 2 is integrally provided on the torsion bar.

FIG. 1 is a side view of the main parts of an electrophotographic copying apparatus 11 to which the present invention is applied. The illustrated apparatus 11 is a copying apparatus using electrophotography, in which a photosensitive drum 12 having a photoconductive layer provided on a conductive drum base is rotatably supported in the direction of the arrow.

Around this drum 12, according to the rotational direction of the drum,
A corona discharger 13, a short focus optical element array 14, a developing device 15, a transfer corona discharger 16, and a cleaning device 17 are provided.

In this device 11, a photosensitive drum 12, a discharger 13, a developing device 15, and a cleaning device 17 are integrally supported within a cartridge 18.

In the copying apparatus described above, the surface of the photosensitive drum 12 is uniformly charged with a predetermined polarity by the corona discharger 13, and then the original on the document platen 20, which is reciprocated at the upper part of the apparatus main body, is charged with a fluorescent lamp 21.
The reflected light is transmitted to the drum 12 via the element array 14.
It is exposed to light to form a latent image. The formed latent image is developed by the developing device 15, and the developed image is transferred to the transfer corona discharge device 1.
6. The transfer paper P on the paper feed tray 22 is fed by a paper feed roller 23, and is conveyed to the transfer section by a timing roller 24 at the same timing. The transfer material that has been transferred is sent to a fixing device 27 via a moving path 26, where it is fixed, and then sent out of the machine by a discharge roller 28.

The main body of the device 11 is similar to the conventional device shown in FIG.
2, the second body part 32 is rotatably connected to the first body part 31 about the bin 33, so that the second body part 32 can be opened and closed with respect to the first body part 31. There is.

In the illustrated embodiment, the second main body portion 32 includes a photosensitive drum 12, a discharger 13, a developing device 15, and a cleaning device 1.
A cartridge 18 that integrally supports the front panel, a short focus optical element array 14, and a fluorescent lamp 21 are provided.
3, a timing roller 24, a transfer corona discharger 16, a moving path 26, a fixing device 27, a discharge roller 28, a driving mechanism thereof, etc. are provided.

In FIG. 1, in order to open the 's2 main body portion 32, the document table 20 is brought to the left end in the figure, and then the second main body portion 23 is opened. In this state, the cartridge 18 can be pulled out toward the front in FIG. 1 and can be replaced, and jams can be cleared through the opening between the first body part 31 and the second body part 32.

Similar to the conventional example shown in FIG.
A torsion bar 34 is provided as a biasing means for applying a rotational moment in the opening direction to the main body portion 31,
At one end thereof, it engages a pin 35 fixed to the second body part 32, imparting a rotational moment to the second body part 32 in the opening direction.

In this embodiment, the torsion bar 34 is not provided so as to pass through the center of rotation of the second body portion as shown in FIG. 4, but is provided to rotate around a point 36 that is offset from the center of rotation. , and the other end (not shown) is fixed to the first body portion 31.

FIG. 2 shows details of a portion of the torsion bar.

The torsion bar 34 is integrally provided with cam portions 34 a and 34 b that control the rotational moment acting on the second body portion 32 depending on the open position of the second body portion 34 . In FIG. 2, a solid line indicates a state in which the second body portion 32 is closed, and a dashed line indicates a state in which the second body portion 32 is opened.

First, with reference to FIGS. 1 and 2, the moment when the second main body portion 32 is opened will be described.

The weight of the second body part 32 is W, the position of the center of gravity is 01, the horizontal distance between the center of rotation and the center of gravity is Ll, and the opening angle of the second body part is A.
Then, the second body portion 32 has M, mWXLl
cosA (7) A moment due to its own weight is acting.

On the other hand, if the torsion bar is already generating a rotational moment MT at the position indicated by the dotted chain line in Figure 2, then the moment M2 acting on the second body portion 32 is here, and L2 is the moment L2 acting on the second body portion 32. Center of rotation 33 of part 32 and pin 3
5 distance, IL2 is the rotation center 36 of the torsion bar 34
to the point of contact with the pin 35, D is the force F2 acting on the pin 35 from the torsion bar 34 and the second body portion 32
It is the angle made with the reference line of Here, in order to maintain the second body portion in an open state, it is sufficient that there is a relationship of Ml <M.

Next, considering the state in which the second main body portion 32 is closed, the moment M3 due to its own weight becomes M3WWXL1. Furthermore, since the torsion bar is twisted by an angle B from the position indicated by the dashed-dotted line to the position indicated by the solid line, the generated moment increases by M degrees.

Further, in this embodiment, the rotation center 3 of the second main body portion 32 is
3 and the rotation center 36 of the torsion bar 34 are not provided on the same axis, so the distance from the rotation center 36 of the torsion bar 34 to the point where it abuts the pin 35 changes from 12 and becomes it 0 In this embodiment, The device is arranged so that 111<112.

Also, when the second main body portion 32 is closed, the torsion bar 3
A cam portion 34a tilted by an angle E is formed at the portion where 4 contacts the bottle 35. In this state, the second main body portion 32
The moment M4 acting on is: where C is the angle between the force F1 acting on the pin 35 and the reference line of the second body portion 32. Therefore, by selecting the angle E of the cam portion 32a, the relationship between the moments M3 and M4 can be optimally selected without unnecessarily increasing the moment M4. In addition, the rotation center 33 and the rotation center 3
By selecting the relationship 11.12, the angles C and D change, so the moment M4 can be controlled. Therefore, when the second body part 32 is closed, the moment acting on the distance L2 between the center of rotation 33 and the engagement with the first body part 31 becomes smaller, thereby reducing the deformation of the second body part 32. things become possible. Furthermore, since the rigidity can be reduced, it is possible to reduce the weight by molding the second main body portion or reducing the number of reinforcing members.

In the above embodiment, the tip of the torsion bar 37 is bent and the cam part is integrally provided, but as shown in FIG. Alternatively, a separate member 38 may be provided, and the cam portion 38a may be formed on this member.

In addition, in the embodiment shown in FIG. 3, a groove-shaped cam part 38b is provided in addition to the slope-shaped cam part 38a, so that a larger force is required when the bottle 35 comes off the groove-shaped cam part 38b. It is also possible to configure it in such a way.

[Effects of the Invention] As described above, according to the present invention, the rotational moment acting on the second main body portion can be controlled by a simple configuration in which the cam portion is integrally provided with the urging means. Furthermore, since the moment acting on the second main body portion is small, it is possible to achieve a reduction in the size and weight of the main body.

Further, since the force required to close the second main body portion can be similarly controlled, it is possible to provide an image forming apparatus with excellent operability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main body of an electrophotographic copying apparatus embodying the present invention, FIG. 2 is a detailed side view of a portion of the torsion bar shown in FIG. 1, and FIG. 3 is a side view showing a modification of the torsion bar. FIG. 4 is a perspective view showing a conventional example. 1... First main body part, 2... Second main body part, 3-1
! ! 1 rotation center, 4... torsion bar, 5...
・Pin, 31...first body part, 32...
2nd main body portion, 33... bottle, 34... torsion bar,
35...Bin 36...Rotation center, 37...
- Torsion bar, 38... cam member.

Claims (2)

[Claims] (1) The main body of the device is composed of a first main body part on the lower side and a second main body part on the upper side that can be divided, the second main body part is rotatably connected to the first main body part, and the second main body part is connected to the second main body part. In an image forming apparatus that can be opened and closed with respect to one main body part, the second
providing a biasing means on the first body part for applying a rotational moment in the direction of opening the body part relative to the first body part, and said rotation acting on the second body part in accordance with the open position of the second body part; An image forming apparatus characterized in that the urging means is provided with a cam portion for controlling moment. (2) The image forming apparatus according to claim (1), wherein the biasing means comprises a torsion bar.