JPH07261490A - Image forming device - Google Patents

Abstract

PURPOSE:To simplify the constitution, to reduce the space and to easily secure the strength by integrally forming the supporting part of a rotary shaft and a member covering an energizing part for pushing up the upper main body on the end part of the lower main body together with the lower main body. CONSTITUTION:The lower main body B and the upper main body A are respectively constituted so that an exterior member and a frame are formed so one body or the exterior member is made attachable and detachable, and the lower frame 15 and the upper frame 9 are coupled with a rotary supporting shaft 16. By the rotary supporting shaft 16, a supporting shaft supporting part 17 formed integrally with the lower frame 15 is connected to a supporting shaft bearing 22 fixed to the upper frame 9 as a single body a pressurizing member 18 for pushing up the upper main body A taking the rotary supporting shaft 16 as the center for instance, a compression coil spring is used and the member 18 is surrounded by a housing wall 19 formed integrally with the lower frame 15, and the housing wall 19 is connected to the supporting shaft supporting part 17 as one body. Moreover, a supporting shaft bearing 22 is pressurized upward against the weight of the upper main body A by the pressurizing member 18 by bringing the slider pin 21a into contact with the slider pin pressing part 22a formed integrally with the supporting shaft bearing 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus in which an apparatus main body is divided into an upper main body and a lower main body, and the upper main body and the lower main body are connected by a support shaft so that they can be opened and closed.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus, an apparatus main body is divided into upper and lower parts and an upper main body is openably and closably supported with respect to a lower main body in order to facilitate operations such as jam clearance, toner replenishment, and development section maintenance. Some of them are connected by a shaft, and in order to facilitate the opening operation when opening the upper main body of these image forming apparatuses, it is known that a biasing means for overcoming the weight of the upper main body is provided. .

FIG. 10 is an exploded perspective view of a conventional example, in which the image forming means and the exterior cover are omitted. Image forming means is separately installed inside the upper frame 9 of the upper main body A and the lower frame 15 of the lower main body B, and the upper and lower frames 9 and 15 can be closed to form an image, and opened to perform maintenance. Is supposed to do.

To connect the upper and lower frames 9 and 15, the fitting fitting portions 17a of the hinges C are fitted into the hinge fitting holes 15a, which are rectangular holes provided on both sides of one side of the lower frame 15, and the flanges 17b are inserted so as not to be shown. Screw the mounting screw of to the lower frame 15,
The hinge C is fixed to the lower frame 15. The brim 17b is integrally provided with the brim 17b, and is provided with a support shaft supporting portion 17 and an urging member storage box 19a which are separated from each other at an upper portion, and the urging member storage box 19a immediately above the mounting fitting portion 17a is provided with a compression coil spring. The biasing member 18 and the slider 21 as described above are housed in the slider 2
The slider pin 21a which is in contact with the above
It is fitted in the guide groove 21 of a so as to be vertically movable. The support bearing 22 is fixed to the upper frame 9, and the lower end of the slider pin retainer 22a fixed to the support bearing 22 is in a position to retain the slider pin 21. The hinge C is fitted with the support bearings 22 so as to sandwich the upper part of the support shaft support portion 17, and the rotary support shaft 16 has a hole 22b in the support shaft bearing 22 and a hole 1 in the support shaft support portion 17.
7c is inserted.

With the above structure, the rotation support shaft 16 of the hinge C is provided.
The upper main body A is opened and closed with respect to the lower main body B by rotating around the center of the upper main body A. When the upper main body A is opened, the biasing member 18 includes the slider 21, the slider pin 21a, and the slider pin retainer 22.
The upper body A is urged upward to be supported via the support bearing 22a.

[0006]

Since the urging member for opening the upper body supports the weight of the upper body near the rotation support shaft, it is sufficient to support the force expanded by the leverage. A biasing force is required, and in addition to the compression coil spring shown in FIG. 10, a torsion bar or an air damper utilizing a gas compression force is used as a biasing member.

The member of the supporting portion of the rotary support shaft 16 that supports the support portion of the biasing member and the upper body is required to have a sufficient biasing force and sufficient strength to support the weight of the upper body.

When opening and closing the upper body, a biasing member,
The supporting portion and the supporting portion of the rotary support shaft are required to have a shape that prevents the risk of pinching a finger, electric wiring or the like.

Conventionally, because of its shape factor or the above-mentioned strength, the hinge C is constituted by another member attached to the lower body as shown in FIG. 1. The supporting portion of the urging means is a separate member from the lower body of the device, and the separate member and the separate member mounting portion of the lower main body must have a strength to withstand a large urging force, and have a large shape due to the strength constraint, and the space corresponding to that is required. Space is required and the device becomes large. 2. The support part of the rotation support shaft for opening and closing the upper body (support shaft support part 1
Also in 7), sufficient strength is required to withstand the large biasing force and the load due to the weight of the upper main body as described above, and the variously reinforced large shapes require a correspondingly large space, which leads to downsizing of the device. Hindering 3. The urging member supporting portion and the mounting portion are required to have a structure in which there is no risk of pinching a finger and cannot be touched directly by the hand, and a structure for preventing bundled electric wire scissors, and a member for covering these parts is required. This complicates the structure of the biasing member supporting portion, which is a separate member from the main body, and increases the cost of the device. 4. In a general configuration of an apparatus in which the upper main body can be opened and closed with respect to the lower main body, for example, a copy document is set on the upper main body side and an optical system, a photosensitive drum and a developing device are provided, while the lower main body side is provided with a paper feeding and conveying system. , A transfer unit and a fixing unit. In this case, if the positional relationship between the upper main body and the lower main body is misaligned, for example, the copy image formed on the upper main body side is transferred to the misaligned position on the paper conveyed on the lower main body side and reaching the transfer position, Part of the copied image may be missing or may be skewed to the transfer paper. Therefore, the accuracy of the alignment between the upper body and the lower body is one of the important factors for improving the image quality of the copy, and the supporting shaft is supported between the lower body and the upper body, and the supporting shaft bearing is attached as a separate member from the main body. Since they are fixed, high precision is required for each member that constitutes the support portion of the opening / closing shaft of the main body and its mounting, and since many members are required for the assembly precision, the equipment configuration or the cost of each member is increased. Connected to.

The present invention solves the above problems by providing a simple structure around the support shaft and around the biasing member mounting portion so that the space is small and strength can be easily obtained.
An object of the present invention is to provide an image forming apparatus that is divided into three parts.

[0011]

According to a first aspect of the present invention, an image forming apparatus main body is divided into an upper main body and a lower main body, and the upper main body can be opened and closed with respect to the lower main body. A biasing member that pushes up the upper main body when the upper main body is opened and a member that covers the biasing member are arranged between the upper main body and the lower main body and are openably and closably connected about the support shaft. In the image forming apparatus, a member for covering the supporting portion and the urging member is provided in parallel with the lower main body and is integrally formed with the lower main body.

According to a second aspect of the present invention, the member for covering the supporting portion of the support shaft and the urging member has a common wall portion over substantially the entire height thereof. It is a forming device.

A third aspect of the present invention is the image forming apparatus according to the second aspect, wherein the common meat portion is a common wall forming a part of a member for covering the biasing member.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIGS. 1 and 2 show Embodiment 1 of the present invention, and FIG. 1 is a vertical sectional view of an image forming apparatus embodying the present invention. In FIG. 1, a document 1 is placed on a platen glass 2, and reflected light from the document 1 emitted by a moving light source 3 is reflected by a mirror group 4 having a fixed mirror and a moving mirror.
It is placed in the mirror group 4 and forms an image on the drum-shaped photoconductor 6 through the lens 5 for enlarging and reducing the original image at the set magnification.

The photoconductor 6 is rotating in the direction of the arrow in the figure,
The original image is formed into a latent image by being uniformly charged by the primary charger 23, and toner is applied to the latent image by the developing device 7 to form a toner image, which reaches the transfer position. The residual toner on the photoconductor 6 after transfer is removed by the cleaning device 8. The above-mentioned members, the lens 5, the movable mirror in the mirror group 4, the motor of the drive source for driving the light source 3, and the power transmission member are mounted in the upper frame 9 of the upper main body A.

In accordance with the formation of the toner image on the photoconductor 6, the transfer paper in the paper feed cassette 10 is fed to one sheet by a paper feed roller (not shown), and the registration roller 11 forms a toner image on the photoconductor 6. The photoconductor 6 and the transfer charger 12 are timed with
Then, the toner image on the photoconductor 6 is transferred to a transfer sheet. After the transfer, the transfer paper supporting the toner image is the guide member 1.
The toner image is guided to the fixing device 3 and reaches the fixing device 14, and the toner image is permanently fixed to the transfer paper and is discharged to the outside of the machine. The above members are attached to the frame 15 of the lower body B. Further, in order to simplify the apparatus, the photoconductor 6, the developing device 7, the paper feeding / conveying member, the fixing device 14, and a drive transmission member between the main motor, which is a drive source (not shown) for driving these, and the main motor are arranged in the upper part. It is attached to the body A side. Further, a main board of a power source for supplying electric power to each of the above-mentioned devices is also arranged in the upper frame 9 at the rear of the upper main body A from the viewpoint of effective use of the space.

In the lower body B and the upper body A, the exterior member and the frame are integrally formed, or the exterior member can be attached to and detached from the integrated frame. In either case, the lower frame 15 and the upper frame 9 are rotatable spindles 16. Are joined by. The rotary support shaft 16 connects a support shaft support portion 17 formed integrally with the lower frame 15 and a single support shaft bearing 22 fixed to the upper frame 9.

A biasing member 18 for pushing up the upper main body A about the rotary support shaft 16 is, for example, a compression coil spring,
It is surrounded by a storage wall 19 formed integrally with the lower frame 15, and the storage wall 19 is continuous and integral with the support shaft support portion 17 as shown in FIG. 9 of the AA enlarged sectional view of FIG. The storage wall 19 and the support shaft support portion 17 have a common meat portion, but in this case, they are a common wall 19a over the entire height of both. Alternatively, although not shown, the storage wall 19 and the support shaft supporting portion 17 may have wall surfaces facing each other over the entire height, and these wall surfaces may be integrally molded by ribs over the entire height. The support shaft support 17 and the storage wall 19 are either a molded product integrated with the lower frame 15 or embedded so as to be integrated when the lower frame 15 is molded.
To prevent fingers, wiring, etc. from being pinched, and to reduce the mounting space of the hinge C, which is provided with a means for connecting the upper body A and the lower body B and for urging the upper body A upwards, to reduce the strength. It is big.

A longitudinal guide groove 20 is provided on the side surface of the storage wall 19 and contacts the upper end turn portion of the urging member 18.
A slider pin 21a on a slider 21 that is vertically movably accommodated therein is vertically movably fitted. The lower end of the biasing member 18 is seated on the bottom plate 19b connected to the storage wall 19, the upper end is in contact with the slider 21, and the slider pin 21a is supported by the support bearing 2
By contacting the slider pin pressing portion 22a which is integral with the unit 2, the support shaft bearing 22 is urged upward and against the weight of the upper main body A. In the state shown in FIG. 1, a locking device (not shown) (not shown) is used for the upper frame 9 and the lower frame 1.
5 is locked to prevent the upper body A from being lifted by the biasing member 18.

FIG. 2 is a view in which a locking device described later is released. The upper body A is rotated with respect to the lower body B by the spring force of the urging member 18, and is rotated about the rotation support shaft 16 to open. In this state, maintenance such as removal of the jammed transfer paper, replenishment of toner, and replacement of the photoconductor 6 is performed.

FIG. 3 is a view of a locking device for preventing the upper main body A provided on the opposite side of the rotary support shaft 16 from opening when the upper main body A is closed.

The hook plate 3 is provided on the upper body A side.
5, one of the rotating hook-shaped levers 31 fixed to the shaft 32 rotatably supported by the bearing plate 35a and urged in the direction of arrow a by a spring (not shown) about the shaft 32 is the upper body. It is housed between the hook plates 35 attached to A. When the upper body A is closed, the lever 31 has a structure in which the hook-shaped tip is hooked on the upper side of the square hole 33 provided in the hook-shaped portion 34 formed integrally with the lower body B. ing. Any one lever 31 has a bell-crank shape as a whole, and the other end different from the one end that is caught by the square hole 33 is pushed by pressing a release button (not shown) protruding above the upper frame 9, The engagement is released.

Here, the urging force of the urging member 18 and the upper body A
2, the weight of the upper body A is W, the urging force of the urging member 18 when the upper body A is opened is P, and the urging force P ′ when the upper body A is closed is P ′ in FIG. , Upper body A
G is the center of gravity when the is opened, L is the horizontal distance from the rotary support shaft 16 to the center of gravity G, and G ′ is the center of gravity when the upper body A is closed.
The horizontal distance from the rotary support shaft 16 to the center of gravity G'is L ', and the pushing force applied vertically downward with the upper side angle of the upper frame 9 at the time of starting to close the upper body A as a force application point being F, the rotary support shaft. The horizontal distance from 16 to the force applying point of the pushing force F is E, the pushing force when closing the upper body A is F ′, the horizontal distance from the rotary support shaft 16 to the applying point of the pushing force F ′ is E ′, and Assuming that the horizontal distance from the rotary support shaft 16 to the center of the biasing member 18 is H, when the upper body A is open, W · L + FE · P = H ····· When the upper body is closed, W · L ′ + F ′ · E ′ = P ′ · H ... Also, the spring constant of the biasing member is K, and the difference between the lengths of the biasing member 18 when the upper body is opened and when it is closed is δ. Then, a relational expression such as P′−P = K · δ ···· is obtained.

An image forming apparatus in which the main body of the apparatus is divided into an upper main body A and a lower main body B, and the upper main body A can be opened and closed with respect to the lower main body B is generally used in a relatively small apparatus. Here, a case will be described in which the present invention is applied to a copying machine capable of copying a document of maximum size Japanese Industrial Standard Paper size A4.

The maximum original is A4 size (210 mm × 29
7 mm), the size of the main body of the device for placing the document horizontally is mm
With the width 430, the depth 438, and the height 280, the above-described various devices related to image formation are arranged and housed.

The weight W of the upper main body A is equal to that of the platen glass 1
0.3N, lens mirror group 10.2N, optical driving device (including motor) 3.9N, original pressure plate 7.1N, power supply unit (including operation display unit) 14.5N, upper body A outer cover ( 15N on the upper frame 9, the main motor driving device 10N, the photoconductor 6, the developing device 7, the cleaning device 8.3N, and the structure 47.4N on the upper frame 9 and the like, W = 126.7N.

As can be seen from FIG. 4, the rotary support shaft 16 has
If the distance from the right end of the upper main body A to the rotary support shaft 16 is increased, the space outside the rotary support shaft 16 into the main body becomes larger when the upper main body A rotates. Considering the effective use of the main body space with a certain dead space, the end of the main body is good, so it should be 13 mm from the right end of the main body of the apparatus. Also, the biasing member 1
8 is also a rotary support shaft 16 from the viewpoint of effective use of the body space
The supporting part of the supporting part is close to the supporting shaft supporting part 17 and is installed at a position where H = 47 mm from the rotary supporting shaft 16 inside the apparatus.

The center of gravity G of the upper body A when the opening angle of the upper body A is set to 35 ° and the upper body A is opened by 35 ° is L = 166 mm from the rotary support shaft 16. Therefore,
Since the upper body A is opened when the upper body A is opened by 35 °, the force of the biasing member 18 that supports the weight 126.7 N of the upper body A is 0 N in the formula. It must be greater than or equal to the force at the time. Substituting the above numerical values into the formula, 126.7 × 166 + 0 × (430−13) = P × 47 Therefore, the biasing force P = 447.5N or more is required.

If the biasing member 18 is, for example, a compression coil spring, the wire diameter φ2.9 mm, the coil diameter φ18 mm, and the free length 17 are taken into consideration when considering the apparatus space and the above-mentioned load conditions.
A coil spring of 2 mm material SWPB was compressed by 51 mm and used as an initial load with the upper body A opened, and the spring constant was 4.405 N / mm from a known coil spring calculation formula.
And the spring force is 2 when the upper body A in FIG. 2 is opened.
When this spring is placed at the front and rear of the device body at 24.6N, 2
24.6N × 2 = 449.2> P.

The spring force of this compression coil spring when the upper body A is closed is that the spring length is changed from 121 mm to 91 mm by closing the upper body A, and the spring δ = 30 mm.
+ Because of the initial load, the amount of compression is 51 mm = 81 mm, so 81 mm x 4.405 N / mm per spring
= 356.8N.

Since two springs are used, 356.
This means that an extremely large biasing force of 8N × 2 = 713.6N is applied.

The positioning of the upper main body A with respect to the lower main body B is carried out in the lateral direction (left-right direction) and the height direction (vertical direction) of the apparatus main body by the side of the lower main body B which supports the above-mentioned two rotary support shafts 16 portions. Is determined by the support shaft support portion 17 and the support shaft bearing 22 on the upper body A side, and the front side wall surface and the rear side of the support shaft support portion 17 in one of the two in the depth direction (front-back direction) It is determined by the inner wall surfaces of the front and rear walls of the support shaft bearing 22 coming into contact with the wall surface (the wall surface perpendicular to the depth direction of the apparatus body).

Further, for the positioning in the depth direction, as shown in FIG. 3, the thickness t dimension portion of the hook-shaped portion 34 on the lower main body B side is provided on the hook plate 35 provided on the upper main body A side.
It is regulated by slipping into the T dimension part of the. Due to this positioning, the rotating main shaft 16 is damaged due to the displacement force of the upper main body A with respect to the lower main body B applied at the time of physical shock such as dropping, and the upper and lower main bodies A, when the upper main body A is closed, It prevents the misalignment and distortion of B.

Here, the T dimension is relative to the t dimension, and the relative position error between the hook-shaped portion 34 and the front and rear side wall surfaces of the support shaft supporting portion 17 (contact portions with the wall surface of the support bearing 22) and the support. Wall surface of bearing 22 (a portion in contact with support shaft support portion 17)
In order to absorb the total positional error between the hook plate 35 and the hook plate 35, a clearance T−t = Δd is provided, and the distortion to the upper main body A, the lower main body B, etc. caused by the deviation of these is minimized. This clearance Δd is actually about 0.3 mm and is equally distributed to both sides. The positional deviation of this angle is Δd / 2 ÷ (the distance from the rotation support shaft 16 to the shaft 32 is 4 when the upper body A is displaced from the lower body B).
(00 mm) = 0.15 / 400 rad, which is an acceptable level for image skew due to skew of the transfer sheet, which is a problem in transfer sheet transportation.

The support shaft supporting portion 17 of the first embodiment is a lower body B.
Since it is located at the end portion of and is integrally formed with the lower frame 15 of the lower body B, it is possible to lighten the side surface. And a support shaft support portion 17 for supporting the upper body A
By forming the urging member storage wall 19 integrally with the lower frame 15 of the lower main body B by being integrally provided over substantially the entire height thereof, the number of parts can be reduced and the cost can be reduced and mounted as compared with the case of the separate structure. The space of a part can be omitted, and since a large load (weight of the upper main body A and biasing force that pushes up the upper main body A) applied to this part between the lower frame 15 and these parts is received, it is smaller than a separate structure. The shape also provides sufficient strength to withstand these high loads.

Since the urging member storage wall 19 is formed integrally with the lower frame 15, a cover for preventing fingers or the like from being touched or pinched when the urging member 18 is operated, an upper main body A and a lower main body B. There is no need to add a cover for preventing the electrical wiring connected between them from being pinched, and the structure can be simplified accordingly, leading to cost reduction of the device.

Since the wall surface of the support shaft support 17 formed integrally with the lower body B is used for the positioning portion with respect to the upper body A, it is not necessary to consider a component mounting error as compared with a separate structure. In terms of strength, since improvement can be expected as described above, there is an effect on the deformation of this portion due to the increase in biasing force generated when the upper body A is closed.
And the positioning accuracy of the upper body A is improved.

Accordingly, when the upper main body A and the lower main body B are misaligned and the copy image is deteriorated, for example, when the upper and lower positions are displaced, the pressure balance between the pair of registration rollers 11 that stably conveys the transfer paper is improved. The transfer paper formed by the upper main body A and the lower main body B is misaligned, or the transfer paper is not conveyed properly such as a skew or a jam, or the upper main body A is slanted with respect to the lower main body B. It is possible to prevent a phenomenon in which the copy image is displaced to the position of the conveyed transfer paper, a phenomenon in which a part of the copy image is missing, or a case where the copy image is oblique to the transfer paper.

For the above-described reason, when the upper body A and the lower body B are positioned by the hook portions (31 to 35) in addition to the support shaft supporting portion 17, the upper body A is positioned.
Is in the depth direction (front-back direction) with respect to the lower body B.
Since the position of the rotary support shaft 16 which is owned by two is fixed, when the position of the rotary support shaft 16 which is owned by two in the depth direction is deviated, the corresponding amount distorts the upper body A or the lower body B, The support shaft supporting portion 17 is strengthened against various distortions of the copied image caused by the movement of the mirror group 4, the image formation, the conveyance of the transfer paper, the fixing, etc., and the deformation due to the load. It is very effective to reduce.

[Embodiment 2] FIG. 5 is a longitudinal sectional view of Embodiment 2 using the present invention, showing an example in which a biasing member is attached to the upper body side. In the figure, the urging member 50 includes an arm 52 rotatable about a rotation shaft 51 provided laterally of the rotation support shaft 16 with respect to the upper body A, and a support plate swingable with respect to the arm 52. It is installed between 53. The tip of the arm 52 is located upward and serves as an upper spring seat 52a, the lower end of the support plate 53 forms a lower spring seat 53b, and the biasing member 50 is contracted between the spring seats 52a and 53b. is there. The mandrel 53a fixed to the lower spring seat portion 53b is inserted through the hole of the upper spring seat portion 52a, and the mandrel 53 is mounted on the upper spring seat portion 52a.
A nut 53c is screwed into the end. By biasing the biasing member 50 toward the upper main body A side, the storage wall 55 that forms the biasing member storage space on the lower main body B side is raised to the bottom to make it smaller, which has the effect of favoring the component arrangement of the lower main body B. is there.

[Third Embodiment] FIG. 6 is a perspective view of the lower frame 15 of the lower body B described in the first embodiment and is shown with the support shaft support portion 17 of the rotary support shaft 16 of the upper body A. In the example in which the wall portion 60 of the biasing member 18 and the wall surfaces 60 and 61 having the exterior cover mounting portion are connected to each other, the support shaft support portion 17 of the rotary support shaft 16 of the upper main body A of the first embodiment described above is provided. Has the effect of reducing the positional deviation between the upper main body A and the lower main body B when the upper main body A is closed, and further reducing various drawbacks of the conventional example.

[Fourth Embodiment] FIG. 7 is a diagram showing an example in which the storage wall of the biasing member is used as a positioning or guiding surface for the biasing member. If the urging member is, for example, a compression coil spring, in order to obtain a large urging force when the upper body A is opened and a very small urging force when the upper body A is closed, the spring should be small and the spring storage space should be small. When considering a spring that makes the compression coil smaller, as in the fourth embodiment, the compression coil spring 75
It is advantageous to place a further compression coil spring 76 inside the. At this time, the inner compression coil spring 76
Is a guide portion 74 provided on the slider 73 and the lower body B.
The compression coil spring 75 on the outer side, which is positioned and attached to the protruding portion 71 formed above, is provided with a guide surface 72 provided on the support shaft supporting portion 70 of the lower main body B and a recess 77 provided on the slider 73. And has been inserted into. A guide surface 78 for guiding the slider 73 having a diameter larger than that of the guide surface 72 of the compression coil spring 75 is also provided on the support shaft supporting portion 70, and is connected to the guide surface 72 by an inclined surface 79.

In the case of using a plurality of compression coil springs 75 and 76 in which the storage space for the compression coil springs, which is the biasing member for pushing up the upper main body A, is reduced, the free length of the spring is set relative to the coil diameter of the spring. The provision of the above-mentioned guide surface 72 and the like connected to the support shaft supporting portion 70 of the lower main body B causes the compression coil spring 7 to expand and contract.
This is an effective measure to reduce the sliding noise by smoothing the movement of the sliding slider 73.

[Embodiment 5] FIG. 8 is a diagram showing a case where the urging portion storage space is changed in the depth direction (front and rear) of the apparatus body.

On the upper body A side, a power board, a drive source for the machine,
When the drive gear train and the like are arranged, it is advantageous in terms of space to arrange them on the back side (rear surface side) of the device when considering the layout of the entire device. In this case, the center of gravity of the upper main body A shifts to the back side (rear surface side), and in order to push up the upper main body A in a well-balanced manner, it is necessary to make the biasing force of the biasing member on the back side of the apparatus stronger than the front side (front side). is there. Therefore, considering the characteristics of a known biasing member (for example, a compression coil spring), it is necessary to secure a longer biasing member storage space on the back side, so in this example, for example, the paper feed cassette 1 for stacking transfer paper.
By using the space (height S) on the back side of 0, the storage space of the biasing member 81 on the back side can be set long from Q to R to effectively use the space of the apparatus. In addition, the biasing member 8 on the back side
The bottom surface (spring seat) 80 of the storage unit 1 may be a part of the lower main body B, or a cassette base metal plate 82 that is a receiving surface of the paper feed cassette 10 may be used. As described above, increasing the storage space of the biasing member 81 on the back side that receives a large load increases the degree of freedom in designing the biasing member 18, and is advantageous in design.

[0047]

As described above, according to the first aspect of the present invention, the end portion of the lower body is provided with a support portion for the rotating shaft when the upper body is opened and closed, and a force for pushing the upper body up against the lower body. By forming the member for covering the biasing member that is integrally formed with the lower body, The structure of these parts is simplified and the manufacturing cost can be reduced by reducing the number of parts. Since they are integrated, the parts to be mounted are not required, and the space is reduced accordingly, and the size of the device can be reduced. 3. The shape of the upper main body supporting portion to which a large load is applied can be made compact without lowering the strength. 4. It is possible to improve the relative positional accuracy between the lower main body and the upper main body, the transportability of the transfer material, and the copy image quality. And so on.

According to a second aspect of the present invention, in the first aspect, the supporting portion of the support shaft and the portion covering the biasing member have a common wall portion over substantially the entire height thereof. Since the portion that receives the force of the biasing member becomes extremely strong, the distance between the support shaft and the biasing member can be reduced and the strength,
Sufficient rigidity can be maintained.

In the third invention of the present invention, since the common wall portion is the common wall in the second invention, the effect of strengthening the portion of the lower body supporting the support shaft is particularly great.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state where an upper body is opened in FIG.

FIG. 3 is a perspective view of the upper main body of FIG. 1 in an open state.

FIG. 4 is a vertical cross-sectional view of the device in which the rotation support shaft of the upper body is located inside.

FIG. 5 is a vertical sectional view of a second embodiment of the present invention.

FIG. 6 is a perspective view of a third embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view of Embodiment 4 of the present invention.

FIG. 8 is a vertical sectional view of a fifth embodiment of the present invention.

9 is an enlarged cross-sectional view taken along the line AA of FIG.

FIG. 10 is an exploded perspective view of a conventional example.

[Explanation of symbols]

 9 Frame of upper main body 15 Frame of lower main body 16 Rotating support shaft 17 Support shaft supporting portion 18 Energizing member for pushing up the upper main body 19 Storage wall 20 Guide groove 21 Slider 22 Support bearing

Claims (3)

[Claims] 1. A device in which an image forming apparatus main body is divided into an upper main body and a lower main body, and the upper main body can be opened and closed with respect to the lower main body, and the upper main body and the lower main body are connected to be openable and closable around a support shaft. A biasing member that pushes up the upper body when the upper body is opened and a member that covers the biasing member are disposed between the upper body and the lower body. An image forming apparatus, which is provided in parallel with a main body and is integrally formed with a lower main body. 2. The image forming apparatus according to claim 1, wherein a member that covers the supporting portion of the support shaft and the urging member has a common wall portion over substantially the entire height thereof. 3. The image forming apparatus according to claim 2, wherein the common meat portion is a common wall that forms a part of a member that covers the biasing member.