JP2013068974A - Casing opening/closing mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casing opening/closing mechanism that provides both user's operability and assemblability while lighting the load on a spring.SOLUTION: The casing opening/closing mechanism includes a casing 22 supported on a device body 2 rotatably so as to open the interior of the device body 2; a link member 52 having its one end 53 rotated on the casing and the other end 55 swung between a support side 62 and an opening side 60, and holding an opening attitude of the casing 22; and a tension spring 90 having its one end 92 connected to the link member and the other end 93 connecting a suspension part 51 capable of moving to a direction connecting the support side 62 and opening side 60, and extending and contracting between those support side 62 and opening side 60 to adjust a load accompanying opening/closing operation of the casing 22. The tension spring 90 contracts as the casing 22 is opened to have a free length, and moves in the state of the free length toward the support side 62 of the casing 22 together with the suspension part 51 through further opening operation.

Description

  The present invention relates to a case opening / closing mechanism applicable to an image forming apparatus represented by a copying machine, a printer, a facsimile, and the like.

An image forming apparatus provided with this type of casing opening / closing mechanism has a document conveying device and an image reading means, for example, a scanner unit, mounted on the upper side of the apparatus main body, and a document set on the document conveying device or a scanner The document placed on the scanner is optically read by the scanner.
In an image forming apparatus using an electrophotographic process, the photosensitive drum of the image forming unit is charged in advance, and the surface of the photosensitive drum is irradiated with light to form an electrostatic latent image. Next, the developed toner image is transferred and fixed on a recording material.

Here, a heavy scanner unit is housed in a housing, and the housing is opened from the apparatus main body so that the inside of the apparatus main body can be visually confirmed. Maintenance of the image forming apparatus and replacement parts such as a toner container are provided. A structure enabling detachment is disclosed (for example, see Patent Documents 1 and 2).
Specifically, in Patent Document 1, an outer wall member that also serves as a paper discharge tray is provided on the rear surface of the casing, and the inside of the apparatus main body can be accessed when the casing is opened with respect to the apparatus main body together with the outer wall member. Also in Patent Document 2, when the casing is lifted from the apparatus main body with the support side as the center, the user can access the apparatus main body.

JP 2009-134227 A JP 2007-251934 A

  By the way, the above-described opening / closing operation of the casing is assisted by an assisting spring. Patent Document 1 discloses a torsion coil spring, and Patent Document 2 discloses a push spring. However, with the former torsion coil spring, the set load becomes very large and the assemblability is difficult. Further, the latter push spring has a problem that it is difficult to dispose in the horizontal direction in which the end portions on the support side and the open side of the casing are connected to each other because a force returning to the free length is generated when compressed in the longitudinal direction. .

This problem can be solved by using a tension spring that generates a force that shrinks and returns to the free length when pulled in the longitudinal direction.
Specifically, the fully open posture of the casing is held by a link member that rises with the opening operation, and the end portion of the link member and the support side of the casing of the apparatus main body are connected by a tension spring, thereby the casing This is because the tension spring that has been stretched contracts during the opening operation, and the casing is quickly opened, and when the casing is closed, the free-length tension spring extends and the casing is slowly closed.

However, if the tension spring is simply used in the above-described conventional technique, a spring having a high allowable stress that can withstand repeated fatigue must be installed if a large opening angle is to be provided, thereby reducing the manufacturing cost. There is no problem.
That is, when the tension spring is suspended on the fixed support side, the tension spring in the fully open position of the casing is in a free length state, while the tension spring in the fully closed position of the casing is The tension spring is required to have specifications that can repeatedly withstand expansion and contraction between the free length state and the most extended state connecting the end portions on the support side and the open side of the housing. This is because that.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a housing opening / closing mechanism that solves the above-described problems and achieves both user operability and assembly while reducing the load on the spring.

  In order to achieve the above object, a first invention is an apparatus main body, a casing that is rotatably supported with respect to the apparatus main body so as to open the inside of the apparatus main body, and one end of the casing that rotates relative to the casing. The other end swings between the support side of the housing and the open side of the housing, and the link member capable of maintaining the open posture of the housing, and one end connected to the link member, the other The end is connected to a suspension that is movable along the direction connecting the support side of the case and the open side of the case, and expands and contracts between the support side of the case and the open side of the case. A tension spring that adjusts the load associated with the opening / closing operation of the housing, and the tension spring contracts with the opening operation of the housing to become a free length. Along with the opening operation, it moves toward the support side of the casing together with the suspension.

According to the first invention, the casing is supported so as to be rotatable with respect to the apparatus main body, and when the casing is opened with respect to the apparatus main body, the inside of the apparatus main body can be viewed from the outside. Moreover, the attitude | position which the housing | casing opened is hold | maintained with a link member.
Here, the tension spring is connected to the link member and the suspension part, respectively, so that the above-described drawbacks of the structure using the torsion coil spring and the push spring can be eliminated. Specifically, the tension spring extends in the closed position of the casing, and contracts with the opening operation of the casing to quickly open the casing, improving user operability and a very large set load. Is also unnecessary, and its assemblability is also improved.

The opening operation of the casing continues even after the tension spring becomes free length, and the free length extension spring slides toward the support side of the casing together with the suspension portion.
Therefore, the amount of extension of the tension spring in the closed posture of the housing is small compared to the case where the suspension portion is fixed to the support side of the housing and does not slide at all. Further, the tension spring does not become a free length for the first time when the casing is fully opened (a timing when no load bias is required), but becomes a free length before the fully opened. As a result, the load on the spring is greatly reduced, and it is possible to reliably withstand repeated fatigue.

According to a second invention, in the configuration of the first invention, the tension spring moves toward the open side of the housing together with the suspension portion in accordance with the closing operation of the housing, and the movement of the suspension portion is stopped. In this case, the free length starts to increase with the further closing operation.
According to the second invention, in addition to the action of the first invention, the tension spring has a free length when the casing is opened, and the tension spring and the suspension portion of the free length are used for closing the casing. Along with this, it slides toward the open side of the housing. That is, the closing operation of the housing is performed in a state where the tension spring has a free length.

  Therefore, the amount of extension of the tension spring in the closed posture of the housing is small compared to the case where the suspension portion is fixed to the support side of the housing and does not slide at all. Furthermore, this free-length tension spring does not start to extend from the fully open time of the housing (timing that does not require load urging), but starts to extend after the suspension portion has stopped sliding. As a result, the load on the spring is greatly reduced, and it is possible to reliably withstand repeated fatigue.

In addition, the tension spring extends with the closing operation of the casing and slowly closes the casing, so that the operability for the user is improved, no very large set load is required, and the assemblability is also improved. .
According to a third aspect of the present invention, in the configuration of the second aspect of the present invention, the suspension portion stopper is in contact with the suspension portion moved toward the open side of the housing between the support side of the housing and the open side of the housing. Is provided.

  According to the third invention, in addition to the action of the second invention, the tension spring is always free length when the suspension part is separated from the suspension stopper, and the tension spring in this state is The suspended portion that has been slid in accordance with the closing operation starts to extend after coming into contact with the stopper. Therefore, the movement of the suspension portion can be surely stopped, and the optimum design of the tension spring can be performed according to the position of the stopper.

According to a fourth aspect of the present invention, in the configuration of the first to third aspects of the invention, the casing is rotatably supported with respect to the apparatus main body, and is configured to be interlocked with an opening / closing operation of the casing. And an opening angle of the outer wall member with respect to the apparatus main body is larger than an opening angle of the housing with respect to the apparatus main body.
According to the fourth invention, in addition to the effects of the first to third inventions, the opening angle of the casing is limited if the opening angle of the outer wall member is increased with respect to the opening angle of the casing. However, the outer wall member can be opened larger, and access to the inside of the apparatus main body is facilitated.

  According to the present invention, since the suspension portion of the tension spring is movable, it is possible to provide a housing opening / closing mechanism capable of reducing the load on the spring and achieving both user operability and assembly performance. .

1 is an external perspective view of a multifunction machine according to an embodiment. It is a schematic block diagram of the multifunction machine of FIG. 1 including a controller. FIG. 2 is a perspective view of the multifunction machine in which an outer wall member of FIG. 1 is opened. It is the side view which showed the fully open attitude | position of the outer wall member of FIG. It is a principal part enlarged view of FIG. It is a side view of the holding link in the fully open posture of FIG. FIG. 5 is a side view of the holding link in a slightly closed posture (a slightly opened posture from the fully closed posture) from the fully open posture in FIG. 4. It is a side view of the holding link in the fully closed posture of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
The housing opening / closing mechanism of the present embodiment is applicable to, for example, an image forming apparatus. FIG. 1 shows a digital multifunction peripheral, which is an example of an image forming apparatus, a so-called multifunction peripheral (hereinafter referred to as MFP) 1 from the upper right front. In the figure, the front of the MFP 1 facing the user and the right side of the MFP 1 can be seen. The MFP 1 includes a box-shaped apparatus main body 2, and a sheet (recording material) is discharged to the upper side of the apparatus main body 2.

Specifically, the inside of the apparatus main body 2 is covered with an outer wall member 6 from above, and the surface 7 of the outer wall member 6 visible in FIG. 1 functions as a paper discharge tray.
Further, the apparatus main body 2 of this embodiment protrudes upward and downward on the left and right sides and the back side of the surface 7 as viewed in FIG. 1, and an optical scanner unit (image reading means) is provided above the apparatus main body 2. ) 20 is installed.

  Further, although not shown in this figure, an automatic document feeder (hereinafter referred to as ADF) can be mounted on the upper side of the scanner unit 20, and when the MFP 1 is used as a copying machine, a facsimile, or a network scanner. The original is conveyed from the ADF, and the image surface is optically read by the scanner unit 20.

  The scanner unit 20 is housed in a casing (housing) 22 described later, and an operation panel 28 is installed on the front side of the casing 22. The operation panel 28 is provided with an operation screen for displaying various information such as a plurality of operation keys used for various operations of the user, character information, and guide images. These operations are notified to the controller 38 of FIG.

On the other hand, a front loading type paper supply device is disposed at the lower part of the apparatus main body 2. Specifically, the supply device has a paper feed cassette 4 (FIG. 1), and the paper feed cassette 4 can store sheets stacked in the thickness direction and can be pulled out from the apparatus main body 2. Is done.
Next, FIG. 2 is a schematic configuration diagram including the controller 38 of the MFP 1.

The MFP 1 is connected to a network via a network interface (IF) 26 and further connected to a public line. The MFP 1 executes various operations in accordance with program instructions.
The MFP 1 has, for example, a printing function (Copy function), a transmission function (Send function), and a storage function (Box function).

Specifically, the HDD 32 includes a box area 34, and sequentially stores various data such as a print job transmitted from the client PC, a scan job read by the scanner unit 20, and a facsimile job received by the FAX communication unit 24. And has a Box function.
Further, the MFP 1 includes a memory 30. The memory 30 includes a ROM, a RAM, and the like, and stores programs for various processing operations.

The above-described FAX communication unit 24 also has a Send function, and transmits a facsimile job stored in the HDD 32 to the other party.
The print engine (image forming means) 10 includes an ADF that transports a document to an image reading position of the scanner unit 20, a paper feed cassette 4 that stores paper, a drum unit 14 that forms an electrostatic latent image corresponding to each color, Connected to the developing unit 16 that develops the toner image using the toner of the corresponding color toner container 18 and the intermediate transfer belt 12 that transfers the toner image onto the paper, the print job stored in the HDD 32 is transferred to the surface 7 of the outer wall member 6. It has a copy function.

The intermediate transfer belt 12, the drum unit 14, the developing unit 16, the toner container 18 and the like are accommodated in the apparatus main body 2 above the paper feed cassette 4. Further, the toner container 18 of the present embodiment is the front of the MFP 1. From the side, they are arranged in order of magenta, cyan, yellow and black.
Returning to FIG. 1 again, the casing 22 of the present embodiment is formed in a substantially rectangular parallelepiped whose longitudinal direction is larger than the width of the front surface of the MFP 1, and a contact glass 23 is disposed on the upper surface thereof.

  The components of the scanner unit 20 are housed in the casing 22 below the contact glass 23. Specifically, the scanner unit 20 includes a carriage for reading image data of a document, a CCD (none of which are shown), and the like. The carriage irradiates light toward the contact glass 23 and extends along the longitudinal direction of the casing 22. Moving. The irradiated light is read by the CCD and converted into a predetermined signal, and an electrostatic latent image of a document image can be formed on the photosensitive drum of the drum unit 14 by the laser unit 13.

  The casing 22 has an upper surface on which the contact glass 23 is disposed and a lower surface 66 covering the lower side of the operation panel 28 and the like (FIG. 3), and the peripheral edges of the upper surface and the lower surface 66 are also shown in FIG. , The front surface 60, the back surface 62 and the side surface 64. Specifically, the side surfaces 64 and 64 face each other at both end portions in the longitudinal direction of the casing 22. The front ends of these side surfaces 64, 64 are connected to a front surface (open side of the housing) 60 on which the operation panel 28 is arranged, and the front surface 60 is connected to a back surface (support side of the housing) 62 located on the back side as viewed in FIG. Confront.

A reading-side fulcrum 68 is provided at an appropriate position on the back surface 62 (FIG. 4), and the casing 22 is rotatably supported by the apparatus body 2.
In addition, a suspension mechanism for connecting the outer wall member 6 is provided on the lower surface 66 of the casing 22 at a position facing the surface 7 of the outer wall member 6. Specifically, as shown in FIGS. 1, 3, and 4, the suspension mechanism of this embodiment includes a rail member 80, an arm portion 42, and a link pin 46. First, the release rail 80 is formed on the lower surface 66. Is formed.

  Specifically, the release rail 80 of the present embodiment has cylindrical main bodies 82 that are positioned at the left and right ends of the surface 7 as viewed in FIG. This opening is formed in a rectangular shape and extends from the front side of the MFP 1 toward the back side. Further, the cylindrical main body 82 is provided with an outer groove 83 and an inner groove 84 penetrating through a peripheral wall connected to each opening (FIGS. 1, 3 and 4). 4 is a cross-sectional view, and the release rail 80 on the right side (the back side in FIG. 3) as viewed from the front of the MFP 1 can be seen in FIG.

  More specifically, the inner groove portion 84 is disposed close to the surface 7 of the cylindrical main body 82 and extends from the front side to the back side of the MFP 1 (FIGS. 1 and 4). On the other hand, the outer groove 83 also extends from the front side to the rear side of the MFP 1 (FIG. 3), but is located on the opposite side of the inner groove 84, and the outer groove 83 and the inner groove 84 are substantially the same. The link pin 46 is received facing the height.

The link pin 46 includes a head 47 and a leg 48, and the head 47 is disposed in the inner groove 84 and the leg 48 is disposed in the outer groove 83.
A hole penetrating the peripheral wall of the cylindrical main body 82 is formed in the cylindrical main body 82 in the vicinity of the back end of the outer groove 83, and the rotary portion 53 of a holding link (holding member) 52 described later is rotated. Support freely.

The casing 22 is provided with a hook member 61a that engages with the apparatus main body 2 (FIG. 4). The hook member 61 a protrudes downward from the lower surface 66 and can be engaged with the protruding left and right sides of the apparatus main body 2 in the vicinity of the front surface 60.
Further, an operation lever 61 is disposed on the front surface 60 on the right side of the operation panel 28 as viewed in FIG. When the operation lever 61 is pulled toward the front side, the engagement between the hook member 61a and the apparatus main body 2 can be released.

On the other hand, the arm portion 42 described above is provided on the surface 7 of the outer wall member 6. The arm portions 42 are also formed at the left and right ends of the surface 7 (FIG. 1), and are received between the peripheral walls having the outer groove portion 83 and the inner groove portion 84 from below the opening of the cylindrical main body 82.
The arm portion 42 is formed with through holes at positions corresponding to the outer groove portion 83 and the inner groove portion 84. The through hole is disposed between the outer groove portion 83 and the inner groove portion 84, and the link pin 46. When the casing 22 and the outer wall member 6 are connected together, the outer wall member 6 is suspended from the casing 22.

Further, as shown in FIG. 4, an outer wall side fulcrum 38 is provided at the inner end of the outer wall member 6, and this outer wall member 6 is also rotatably supported by the apparatus main body 2 in the same manner as the casing 22.
As described above, the casing 22 and the outer wall member 6 are connected by the lower surface 66 on which the surface 7 is projected, whereas the casing 22 and the apparatus main body 2 are connected outside the outer wall member 6. ing. Specifically, holding links 52 are provided on the outer sides of the opening rails 80 as viewed from the outer wall member 6 (FIGS. 3 and 4).

  A rotation portion 53 is formed at one end of the holding link 52 (FIGS. 4 and 5), and this rotation portion 53 is connected to the above-described hole near the outer groove portion 83. On the other hand, a slide portion 54 is formed at the other end of the holding link 52, and this slide portion 54 has a round pin 55, and this round pin 55 is formed on the protruding left and right sides of the apparatus body 2. The holding rail 50 is supported so as to be swingable.

  The slide portion 54 is biased by an assisting tension coil spring (tensile spring) 90 (FIGS. 4 and 5). Specifically, as will be described later, the tension spring 90 connects the slide portion 54 of the holding link 52 and the suspension portion 51 on the back side of the apparatus body 2 to open the casing 22, that is, in FIG. When the posture is changed to the posture of FIG. 3, the slide portion 54 is quickly moved toward the back side of the apparatus main body 2. On the other hand, when the casing 22 is closed, that is, when the posture of FIG. 3 is changed to the posture of FIG. 1, a damper function for slowly moving the slide portion 54 toward the front side of the apparatus main body 2 is provided. Yes.

  In the MFP 1, when the operation lever 61 is pulled toward the front side in the state of FIG. 1 to disengage the hook member 61 a from the apparatus main body 2, the front surface 60 side of the casing 22 is lifted by about 10 mm from the apparatus main body 2. . This is because the casing 22 is pushed up by the protrusion 49 shown in FIG. More specifically, trigger springs (not shown) are respectively provided on the protruding left and right sides of the apparatus main body 2 to urge the protrusions 49 upward. Thereby, when the engagement between the hook member 61a and the apparatus main body 2 is released, the protrusion 49 pushes up the front surface 60 side of the casing 22 by the biasing force of the spring.

  Subsequently, when the user lifts the front 60 side of the casing 22 with his / her hand, the release rail 80 is tilted, and the rotating portion 53 of the holding link 52 is directed from the front side of the MFP 1 to the back side with respect to the release rail 80. The slide part 54 moves along the holding rail 50 from the front side of the MFP 1 toward the back side. As a result, the casing 22 starts to open in the direction of the arrow in FIG. 4 with the reading side fulcrum 68 as the center.

  At the same time, the arm portion 42 of the outer wall member 6 has a link pin 46 positioned at the right end of the inner groove portion 84 (a position on the front side of the outer groove portion 83 or the inner groove portion 84 as viewed in FIG. ) Toward the left end position of the inner groove portion 84 (the outer groove portion 83 or the deeper position of the inner groove portion 84), and the outer wall member 6 opens in the direction of the arrow in FIG. Angle: about 60 °).

The opening angle of the outer wall member 6 is further increased if the distance between the reading side fulcrum 68 and the outer wall fulcrum 38 is increased.
Here, the holding rail 50 is provided with a stopper 56 (FIG. 5). The stopper 56 is provided at a position in contact with the slide portion 54 of the holding link 52 in the posture shown in FIGS. 3 and 4, and can hold the fully opened position of the outer wall member 6.

  Specifically, the stopper 56 is urged upward by a stopper spring 58 (FIG. 5), the slide portion 54 moves toward the rear side of the MFP 1 along the holding rail 50, and the slide portion 54 is moved. When coming into contact with the stopper 56, the stopper 56 is pushed downward of the holding rail 50 against the urging force of the stopper spring 58.

  On the other hand, when the slide portion 54 further moves toward the rear side of the MFP 1 from the position of the pushed stopper 56, the stopper 56 jumps out above the holding rail 50 by the biasing force of the stopper spring 58, and the slide portion 54 is locked (FIG. 5). Thus, the casing 22 opened in the direction of the arrow in FIG. 4 with the reading side fulcrum 68 as the center is held in the posture shown in FIGS. 3 and 4 (opening angle: about 40 °).

  3 and 4, when the back surface 8 of the outer wall member 6 is visible from the outside, the user can use the service unit housed in the apparatus main body 2, which is the above-described example. The intermediate transfer belt 12, the drum unit 14, the developing unit 16, the toner container 18, and the like can be accessed, and these can be easily replaced.

By the way, the tension spring 90 described above can move between the front side and the back side of the MFP 1 in a free length state as the slide portion 54 moves.
Specifically, the tension spring 90 of the present embodiment is disposed in a substantially horizontal direction, and as shown in FIG. 5, a front end (one end) 92 located on the front side of the MFP 1 and a rear end ( The other end) 93, and the front end 92 is connected to the slide portion 54 and the rear end 93 is connected to the suspension portion 51.

  The suspension portion 51 of the present embodiment is formed in a substantially L shape in cross section and has a standing wall portion on the back side of the MFP 1, and the rear end 93 of the tension spring 90 is hooked on this standing wall portion. Further, the lower surface portion of the suspension portion 51 is supported by the apparatus main body 2 in a free state, and is disposed at a height substantially equal to the holding rail 50. The suspension unit 51 is configured to be movable between the front side and the back side of the MFP 1 on the back side of the MFP 1 with respect to the stopper 56.

  More specifically, a suspension portion stopper 57 is erected on the apparatus main body 2 in the vicinity of the stopper 56, and the suspension portion stopper 57 is a front end portion opposite to the standing wall portion of the suspension portion 51. When the contact is made, the suspension unit 51 is prevented from moving to the front side of the MFP 1. On the other hand, the amount of movement of the MFP 1 to the back side of the MFP 1 is determined by the length of the free length of the tension spring 90.

That is, in the fully open position of the outer wall member 6, as shown in FIG. 6, the slide portion 54 of the holding link 52 is locked to the stopper 56, and the suspension portion 51 is located on the innermost side of the casing 22. The spring 90 is in a free length state.
Here, when the casing 22 is closed, that is, when the user pushes the front surface 60 side of the casing 22 downward with his / her hand, the slide portion 54 pushes the stopper 56 downward, along the holding rail 50 and the rear surface of the MFP 1. Start moving from side to front.

At the same time, the tension spring 90 and the suspension part 51 are also moved by the slide part 54 and start moving from the back side to the front side of the MFP 1. In other words, the tension spring 90 moves toward the front side of the MFP 1 in a free length state where no spring load is generated until the suspension portion 51 contacts the suspension portion stopper 57.
Next, the outer wall member 6 is in a slightly closed position from the fully open position, specifically, the slide portion 54 moves beyond the stopper 56 and further moves along the holding rail 50 toward the front side of the MFP 1, and the suspension portion 51 is moved. When coming into contact with the suspension stopper 57, the free-length tension spring 90 starts to extend toward the front side of the MFP 1 (FIG. 7).

  Thereafter, when the slide portion 54 further moves to the front side of the MFP 1, the fully closed position of the outer wall member 6 shown in FIG. 1 is reached. In this closed position, as shown in FIG. 8, the holding link 52 that has stood up completely falls down, and the slide portion 54 reaches the most front side of the MFP 1. Then, the tension spring 90 which has started to extend after the movement of the MFP 1 to the front side of the MFP 1 is blocked is in the most extended state in this posture.

  On the other hand, when the user lifts the front 60 side of the casing 22 in the closing operation of the casing 22 from FIG. 8, that is, in the fully closed position of the outer wall member 6 shown in FIG. The holding link 52 starts to stand up by moving toward the back side of the MFP 1 along the rail 50. At the same time, the tension spring 90 in the most extended state starts to shrink.

  Subsequently, even when the outer wall member 6 changes from the fully closed posture to a slightly opened posture, the tension spring 90 continues to contract while the suspension portion 51 is in contact with the suspension portion stopper 57 (FIG. 7). Then, when the slide portion 54 further moves to the back side of the MFP 1 and the tension spring 90 that has continued to contract is in a free length state, the contact between the suspension portion 51 and the suspension portion stopper 57 is released, and the suspension portion 51 is suspended. It leaves | separates from the stopper 57 for parts.

  Thereafter, when the slide part 54 further moves to the back side of the MFP 1, the suspension part 51 is pushed by the tension spring 90 in a free length state and moves on the extension line of the holding rail 50 toward the back side of the MFP 1. Then, as shown in FIG. 6, when the holding link 52 rises and the slide portion 54 is locked to the stopper 56, the suspension portion 51 is moved to the depth of the casing 22 by the length of the free length of the tension spring 90. Will be located on the side.

  As described above, according to the present embodiment, the casing 22 in which the scanner unit 20 is housed is supported so as to be rotatable with respect to the apparatus main body 2, and when the casing 22 is opened with respect to the apparatus main body 2, the outer wall member 6 is interlocked with the opening operation of the casing 22, and the print engine 10 in the apparatus main body 2 can be viewed from the outside. The posture in which the casing 22 and the outer wall member 6 are opened is held by the holding link 52.

  Here, the tension spring 90 is connected to the slide portion 54 and the suspension portion 51 of the holding link 52, respectively, and the above-described drawbacks of the structure using the torsion coil spring and the push spring can be solved. Specifically, the tension spring 90 extends in the closed position of the outer wall member 6 and contracts with the opening operation of the casing 22 to quickly open the casing 22, thereby improving user operability and extremely large. No set load is required, and the assemblability is improved.

The opening operation of the casing 22 continues even after the tension spring 90 becomes free length, and the free length tension spring 90 slides toward the back side of the MFP 1 together with the suspension portion 51.
Therefore, the extension amount of the tension spring 90 in the fully closed posture of the outer wall member 6 can be reduced as compared with the case where the suspension portion 51 is fixed to the back side of the MFP 1 and does not slide at all. In addition, the tension spring 90 does not become a free length for the first time when the outer wall member 6 is fully opened (a timing at which load urging is not required), but becomes a free length before the full opening. As a result, the load on the spring 90 is greatly reduced, and it is possible to reliably withstand repeated fatigue.

The tension spring 90 has a free length when the outer wall member 6 is fully opened, and the free length tension spring 90 and the suspension 51 slide toward the front of the MFP 1 as the casing 22 is closed. That is, the closing operation of the casing 22 is performed with the tension spring 90 in a free length state.
Therefore, also in this case, the amount of extension of the tension spring 90 in the fully closed posture of the outer wall member 6 can be reduced as compared with the case where the suspension portion 51 is fixed to the back side of the MFP 1 and does not slide at all. Furthermore, the free-length tension spring 90 does not start to extend from the fully open time of the outer wall member 6 (timing that does not require load urging), but starts to extend after the suspension portion 51 is stopped from sliding. As a result, the load on the spring 90 is greatly reduced, and it is possible to reliably withstand repeated fatigue.

Further, since the tension spring extends along with the closing operation of the casing 22 and closes the casing 22 slowly, the operability for the user is improved, a very large set load is unnecessary, and the assemblability is also improved. .
Further, the tension spring 90 is always free when the suspension 51 is separated from the suspension stopper 57, and the tension spring 90 in this state is suspended by the suspension 51 that has been slid as the casing 22 is closed. It begins to grow after contacting the part stopper 57. Therefore, the movement of the suspension part 51 can be stopped reliably, and the tension spring 90 can be optimally designed according to the position of the suspension part stopper 57.

Furthermore, if the opening angle of the outer wall member 6 is made larger than the opening angle of the casing 22, the outer wall member 6 can be opened more greatly even when the opening angle of the casing 22 is limited, and access to the inside of the apparatus main body 2 can be achieved. Becomes easier.
The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims.

For example, in the above embodiment, the casing 22 has the outer wall member 6 and the back surface 8 of the outer wall member 6 covers the toner container 18 and the like. However, the present invention is not necessarily limited to this form. The lower surface 66 of the device may constitute an exterior wall of the apparatus main body 2 and directly cover the toner container 18 and the like.
The above-described MFP 1 is an example of an image forming apparatus, and the present invention is naturally applicable to a copying machine, a printer, a facsimile machine, and the like in which the inside of the apparatus body is opened by opening the casing.

  In any of these cases, similarly to the above, there is an effect of achieving both user operability and assembly while reducing the load on the spring.

1 MFP (enclosure opening / closing mechanism)
2 Device body 6 Outer wall member 10 Print engine (image forming means)
20 Scanner unit (image reading means)
22 Casing (housing)
51 Suspension 52 Link member (holding link)
53 Rotating part (one end)
54 Slide part 55 Round pin (other end)
57 Suspension stopper 60 Front (open side of housing)
62 Rear (support side of the housing)
90 Tension coil spring for assist (tension spring)
92 Front end (one end)
93 Rear end (other end)

Claims (4)

The device body;
A housing that is rotatably supported with respect to the apparatus body to open the apparatus body;
One end of the link member rotates with respect to the casing, and the other end swings between the supporting side of the casing and the opening side of the casing, and can hold the opening posture of the casing. When,
One end of the casing is connected to the link member, and the other end is connected to a suspension that is movable along a direction connecting the support side of the casing and the open side of the casing. A tension spring that expands and contracts between the support side and the open side of the housing to adjust the load associated with the opening and closing operation of the housing;
The tension spring contracts with the opening operation of the housing to become a free length, and in this free length state, the tension spring and the suspension portion are directed toward the support side of the housing with the further opening operation. A case opening and closing mechanism characterized by moving. The housing opening / closing mechanism according to claim 1,
The tension spring moves toward the opening side of the housing together with the suspension portion with the closing operation of the housing, and with the further closing operation with the movement of the suspension portion stopped. A case opening and closing mechanism characterized by starting to extend from its free length. The housing opening / closing mechanism according to claim 2,
A casing is provided between the support side of the casing and the opening side of the casing, and a suspension stopper is provided that contacts the suspension that has moved toward the opening side of the casing. Opening and closing mechanism. The housing opening / closing mechanism according to any one of claims 1 to 3,
The casing is rotatably supported with respect to the apparatus main body, and is configured to be interlocked with an opening / closing operation of the casing, and includes an outer wall member that externally covers the image forming unit,
A casing opening / closing mechanism, wherein an opening angle of the outer wall member with respect to the apparatus main body is larger than an opening angle of the casing with respect to the apparatus main body.

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