JP7147382B2 - Snap-fit coupling structure and image forming apparatus - Google Patents

Description

The present invention relates to a snap-fit coupling structure and an image forming apparatus.

A first frame holding a process means, a second frame disposed at an end of the first frame, and a connecting structure for connecting the second frame to the first frame. The unit of the image forming apparatus comprising an elastic locking means integral with one of the first and second frames and a cover provided on the other of the first and second frames. A unit of an image forming apparatus is known which has a locking portion, a fitting portion formed on the back side of the elastic locking means, and an anti-falling member fitted into the fitting portion to prevent the elastic locking means from falling. (Patent Document 1).

A fixing member that heats and melts a toner image to fix it on a recording medium, a pressure member that presses against the fixing member to form a nip portion through which the recording medium is conveyed, and a recording medium that is delivered from the nip portion. a guide member disposed at a position facing the non-fixing surface of the recording medium and guiding the recording medium, wherein the guide member includes a plurality of ribs disposed so as to be linearly contactable with the recording medium. A rib-shaped member is detachably provided, and the rib-shaped member includes a hook portion that engages with the first hole portion of the guide member without being deformed, and a deformable portion that is deformed with respect to the second hole portion of the guide member. Also known is a fixing device including a snap-fit portion that engages by

JP-A-2003-195727 JP 2009-258247 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a snap-fit connection structure and an image forming apparatus that enable reliable connection by a normal snap-fit operation.

In order to solve the above problems, the snap-fit connection structure according to claim 1,
A snap-fit connection structure in which a claw portion formed at the tip of a flexible cantilever portion of a connecting member is elastically engaged with a connecting portion of a member to be connected,
A plate-like member attached to the member to be joined so as to rotate about a rotation shaft and a pressing spring are maintained in a state in which the plate-like member is pressed in a direction to block the connecting portion by the pressing spring. and pressing the claw portion in the direction in which the engaging surface of the claw portion provided on the coupling member extends at the tip portion of the plate-like member, and when the coupling of the claw portion of the coupling member is released, the pressing spring provided with a pressing means for blocking the connecting portion in a state of being pressed against
It is characterized by

The invention according to claim 2 is the snap-fit joint structure according to claim 1 ,
The plate-shaped member presses and contacts at an angle of 45 degrees or less with respect to the insertion direction of the cantilever portion in a state in which the claw portion is pressed in the direction in which the engaging surface of the claw portion extends.
It is characterized by

The invention according to claim 3 is the snap-fit joint structure according to claim 2 ,
The pressing force of the pressing spring is greater than the elastic force acting on the cantilever beam portion in the direction in which the claw portion separates from the coupling portion of the member to be coupled when the cantilever beam portion is inserted into the opening. too big,
It is characterized by

The invention according to claim 4 is the snap-fit coupling structure according to any one of claims 1 to 3 ,
The pressure spring is a torsion spring disposed so as to sandwich a portion fixed to the member to be joined and a portion of the plate-shaped member between two arms,
It is characterized by

In order to solve the above problems, the image forming apparatus according to claim 5 includes:
an image forming means for forming an image on a recording medium;
A cover member comprising the snap-fit coupling structure according to any one of claims 1 to 4 and covering the image forming means,
It is characterized by

According to the inventions of claims 1 and 5 , it is possible to achieve reliable coupling by a normal snap-fitting operation, as compared with the case where no pressing means is provided.

According to the second aspect of the invention, the claw portion of the connecting member can be reliably moved along the engaging surface to the connecting portion of the member to be connected and connected.

According to the third aspect of the invention, even if the cantilever portion of the connecting member is tilted with respect to the insertion direction, the claw portion of the connecting member can be moved along the engaging surface to move the connecting portion of the member to be connected. can be moved to

According to the fourth aspect of the invention, the plate member can be pressed with a simple configuration.

It is a perspective view which shows the snap-fit joint structure which concerns on this embodiment. (a) is a schematic cross-sectional view showing a state in which a joining member and a member to be joined are joined, and (b) is a schematic cross-sectional view showing a state in which the joining member is separated from the member to be joined. (a) is a plan view showing a plate member, and (b) is a side view. FIG. 5 is a schematic cross-sectional view for explaining an operation in which the cantilever portion of the connecting member enters the connecting hole of the member to be connected and the pressing mechanism presses the claw portion; It is a cross-sectional schematic diagram explaining the action angle of the plate-shaped member which pushes in a claw part. FIG. 5 is a schematic cross-sectional view for explaining the operation of the pressing mechanism pressing the claw portion when the cantilever beam portion of the coupling member is tilted. 1 is a perspective view showing the rear side of an image forming apparatus to which a snap-fit coupling structure according to the present embodiment is applied; FIG. FIG. 4 is a schematic cross-sectional view showing a state in which the shield case cover is joined to the main body cover by snap-fitting; FIG. 4 is a schematic cross-sectional view showing a state in which the shield case cover is removed from the main body cover; FIG. 4 is a schematic cross-sectional view showing a snap-fit coupling structure of a comparative example that does not have a pressing mechanism;

Next, with reference to the drawings, the present invention will be described in more detail with reference to embodiments and specific examples, but the present invention is not limited to these embodiments and specific examples.
In addition, in the explanation using the drawings below, it should be noted that the drawings are schematic, and the ratio of each dimension is different from the actual one. Illustrations other than members are omitted as appropriate.
(1) Overall Configuration of Snap-Fit Connection Structure FIG. 1 is a perspective view showing a snap-fit connection structure 1 according to the present embodiment, and FIG. 3(b) is a schematic cross-sectional view showing a state in which the coupling member 10 is separated from the member 20 to be coupled, FIG. 3 is a plan view showing the plate member 31, and FIG. 3(b) is a side view.
Hereinafter, the overall configuration of the snap-fit joint structure 1 will be described with reference to the drawings.

As shown in FIG. 1, the snap-fit joint structure 1 includes a joint member 10 having a claw portion 13 formed at the tip of a flexible cantilever portion 12, and a joint for receiving the claw portion 13 of the joint member 10. A member to be joined 20 having a hole 21 and a pressing mechanism 30 as an example of a pressing means for pressing the claw portion 13 of the coupling member 10 in the direction in which the engaging surface 13a of the claw portion 13 extends.

The coupling member 10 is entirely made of synthetic resin, and is formed such that a flexible cantilever portion 12 protrudes from a main body 11 as shown in FIG. 2(a). Although the number of cantilever beams 12 is not specified in FIG. 2( a ), it may be one or more depending on the specific coupling mode of the coupling member 10 and the member to be coupled 20 in the snap-fit coupling structure 1 . .

A claw portion 13 projecting in a direction crossing the extending direction of the cantilever portion 12 is integrally erected on the tip side of the cantilever portion 12 . The claw portion 13 is composed of a guiding portion 13 b inclined with respect to the insertion direction of the member 20 to be coupled into the coupling hole 21 and an engaging surface 13 a extending in a direction intersecting the cantilever portion 12 .
The claw portion 13 is inserted through the coupling hole 21 of the member to be coupled 20, and the engaging surface 13a is elastically engaged with the coupling surface 20a as the coupling portion of the member to be coupled 20, thereby connecting the coupling member 10 to the member to be coupled 20. (snap-fit connection).

The member 20 to be joined has a joint hole 21 passing therethrough, receives the cantilever beam portion 12 of the joint member 10 from the joint hole 21, and the engaging surface 13a of the claw portion 13 is one of the circumferences of the joint hole 21. It is elastically engaged with the coupling surface 20a.

A pressing mechanism 30 is arranged on the side facing the connecting surface 20a with the connecting hole 21 of the member to be connected 20 interposed therebetween.
The pressing mechanism 30 comprises a plate-like member 31 having a rotating shaft 31a and rotatable around the rotating shaft 31a, and a pressing spring 32 disposed between the plate-like member 31 and the member 20 to be joined.

Specifically, as shown in FIG. 2 , the plate-like member 31 has a rotation shaft 31 a protruding in the width direction of the plate-like member 31 on one end side of the side surface of the plate-like member 31 . It is rotatably supported by a bearing portion 22 erected from the inner side (the side opposite to the coupling member 10). A boss portion 31 b that protrudes in the width direction of the plate-like member 31 is formed at substantially the center of the side surface of the plate-like member 31 .

As shown in FIGS. 1 and 3, the plate-shaped member 31 configured in this manner has a winding portion 32a inserted through the rotating shaft 31a, and one end side of the arm portion 32b is fixed to the coupling surface 20a of the member 20 to be coupled. An arm portion 32b on the other end side is pressed by a pressure spring 32 (hereinafter referred to as a torsion spring 32) fixed to the boss portion 31b of the plate-like member 31 so as to always close the coupling hole 21. As shown in FIG.
Thus, the plate-like member 31 is a lid having a size that covers the coupling hole 21 , and the coupling member 10 is not coupled to the coupled member 20 (the cantilever portion of the coupling member 10 is attached to the coupling hole 21 ). 12 is not inserted), the inside of the member to be joined 20 in which the joining hole 21 is formed is invisible from the outside.

(2) Operation of snap-fit coupling structure FIG. 4 is a cross-sectional schematic diagram for explaining the operation of the cantilever portion 12 of the coupling member 10 entering the coupling hole 21 of the member to be coupled 20 and the pressing mechanism 30 pressing the claw portion 13. 5 is a schematic cross-sectional view for explaining the angle of the plate-shaped member 31 that pushes the claw portion 13. FIG. FIG. 10 is a schematic cross-sectional view for explaining the pressing operation, and FIG. 10 is a schematic cross-sectional view showing a snap-fit coupling structure of a comparative example that does not include the pressing mechanism 30. As shown in FIG.
The snap-fit operation of the snap-fit joint structure 1 according to this embodiment will be described below with reference to the drawings.

When connecting the connecting member 10 to the connecting member 20 by snap-fitting, as shown in FIG. Insert into coupling hole 21 .

The coupling hole 21 of the coupled member 20 is closed from the inside (the side opposite to the coupling member 10) by a plate member 31. The plate member 31 is pressed in the closing direction by a torsion spring 32 to rotate the rotation shaft 31a. , the coupling member 10 (cantilever portion 12) is inserted into the coupling hole 21 with a pressing force F2 greater than the pressing force of the torsion spring 32 (see F2>F1 in FIG. 4A). .

As shown in FIG. 4(b), the claw portion 13 of the connecting member 10 that has entered through the connecting hole 21 of the member to be connected 20 is pressed by the plate-like member 31 in the direction in which the engaging surface 13a of the claw portion 13 extends with a force F3. Being pressed, the engaging surface 13a moves along the connecting surface 20a of the member to be connected 20 (see arrow R in FIG. 4(b)). As a result, the engaging surface 13a of the connecting member 10 is elastically engaged with the connecting surface 20a of the member to be connected 20, and the connecting member 10 is connected to the member to be connected 20 by snap-fitting.

Here, depending on the posture of the plate member 31 contacting the claw portion 13, the action of pushing the engaging surface 13a of the claw portion 13 along the coupling surface 20a of the member 20 to be coupled differs. In the snap-fit coupling structure 1 according to the present embodiment, as shown in FIG. 5, the plate-like member 31 presses the claw portion 13 of the coupling member 10 in the direction in which the engaging surface 13a of the claw portion 13 extends. It contacts and presses at an angle θ of 45 degrees or less with respect to the insertion direction of the beam portion 12 .

Specifically, as shown in FIG. 5, the angle θ between the cantilever beam portion 12 into which the plate member 31 is inserted is 45 degrees or less (FIG. 5 shows a state of about 20 degrees). In this case, the pressing force F0 with which the arm portion 32b of the torsion spring 32 presses the boss portion 31b of the plate-like member 31 is stronger than when the angle θ is large.
Therefore, the pressing force F3 of the claw portion 13 due to the pressing force F0 also increases, and the claw portion 13 of the connecting member 10 is reliably moved along the engaging surface 13a to the connecting surface 20a of the member to be connected 20 to be connected. be able to.

The claw portion 13 of the coupling member 10 is provided at the distal end portion of the cantilever beam portion 12 formed so as to protrude from the main body 11 of the coupling member 10 so as to have flexibility. Such a connecting member 10 is molded using a synthetic resin, but since it has a cantilever structure, a certain tilt (warp) may occur even if the mold structure and molding conditions are adjusted. . If snap-fit coupling is performed in a state where the cantilever portion 12 is tilted, there is a risk that the claw portion 13 will not be sufficiently engaged with the coupling surface 20a of the member 20 to be coupled, as shown in FIG.

FIG. 6 schematically shows how the pressing mechanism 30 presses the claw portion 13 when the cantilever portion 12 of the coupling member 10 is bent (warped).
When connecting the connecting member 10 to the member to be connected 20 by snap-fitting, as shown in FIG. insert into When the cantilever portion 12 is tilted, the claw portion 13 is obliquely inserted into the coupling hole 21 .

The coupling hole 21 of the coupled member 20 is closed from the inside (the side opposite to the coupling member 10) by a plate member 31. The plate member 31 is pressed in the closing direction by a torsion spring 32 to rotate the rotation shaft 31a. is rotationally supported, the coupling member 10 (cantilever beam portion 12) is inserted into the coupling hole 21 with a pressing force F2 greater than the pressing force of the torsion spring 32 (see F2>F1 in FIG. 6A). .

The claw portion 13 of the connecting member 10 obliquely entering from the connecting hole 21 of the member to be connected 20 is connected to the connecting surface 20a of the member to be connected 20 as shown by the broken line in FIG. 6(b). is not sufficiently applied.
Here, when the claw portion 13 is pressed with a pressing force F3 larger than the elastic force G acting in the direction away from the connecting surface 20a of the member to be connected 20, the engagement surface 13a is along the connecting surface 20a of the member to be connected 20. (see arrow R in FIG. 6(b)). As a result, the engaging surface 13a of the connecting member 10 having the tilted (warped) cantilever beam portion 12 is elastically engaged with the connecting surface 20a of the to-be-connected member 20, and the connecting member 10 is snap-fitted to the to-be-connected member 20. Combined.

"Example"
FIG. 7 is a perspective view showing the rear side of the image forming apparatus 100 to which the snap-fit joint structure 1 according to the present embodiment is applied, and FIG. 9 is a schematic cross-sectional view showing a state in which the shield case cover 210 is removed from the body cover 200. FIG.
The snap-fit connection structure between the shield case cover 210 as a connecting member and the body cover 200 as a member to be connected will be described below with reference to the drawings.

The image forming apparatus 100 includes an image forming section 110 that forms an image by an electrophotographic method, a reading section 120 that is arranged above the image forming section 110 and reads an original or the like, and an operation information section 130 (unused) as a user interface. ) and a control device 140 (see FIGS. 8 and 9) that controls the operation of the image forming apparatus 100 .
Between the image forming section 110 and the reading section 120, an internal space S is formed, and a sheet discharge tray section T for stacking sheets P discharged from the image forming section 110 is formed.

Control device 140 is housed in shield case 150 and fixedly arranged on one side (rear side) of image forming apparatus 100 . One surface of the shield case 150 can be accessed from the outside when the snap-fit coupling of the shield case cover 210 from the body cover 200 is released, as shown in FIG. 7(b).

When the lids 151, 152, and 153 attached to the outer surface portion 150A of the shield case 150 are removed, an opening is formed, which is used for maintenance of the image forming apparatus 100 or for expansion equipment for expanding the functions of the image forming apparatus 100. At the time of attachment, the connector C (see FIGS. 8 and 9) of the control device 140 can be accessed through the opening. Specifically, diagnostic equipment and expansion equipment during maintenance are connected to the connector C through the opening, and the shield case cover 210 remains removed.

It is the shield case cover 210 detachably mounted on the main body cover 200 by snap-fitting that allows or disables access to the outer surface portion 150A of the shield case 150 from the outside.

The shield case cover 210 is an example of the coupling member according to the present embodiment, is made entirely of synthetic resin such as ABS or PC/ABS, and has flexibility from the body 211 as shown in FIG. 7(b). A cantilever portion 212 is formed to protrude. A shield case cover 210 according to this embodiment has two cantilever beams 212 formed at the ends of the main body 11 .

The body cover 200 is an example of a member to be joined according to the present embodiment, and has a through hole 201 through which the cantilever portion 212 of the shield case cover 210 is received. Surface 213a is resiliently engaged with coupling surface 200a, which is one of the perimeters of coupling hole 201. As shown in FIG.

A plate-like member 310 having a rotating shaft 310a and rotatable around the rotating shaft 310a, and a plate-like member 310 and the body cover 200 are provided on the side facing the connecting surface 200a with the connecting hole 201 of the main body cover 200 interposed therebetween. A biasing mechanism 300 is arranged consisting of a torsion spring 320 disposed therebetween.

As shown in FIG. 8, the claw portion 213 of the shield case cover 210 which has entered through the coupling hole 201 of the main body cover 200 is pressed by the plate-like member 310 in the direction in which the engaging surface 213a of the claw portion 213 extends with a pressing force F3. The engaging surface 213a of the shield case cover 210 is elastically engaged with the connecting surface 200a of the body cover 200, so that the shield case cover 210 is snap-fitted to the body cover 200. As shown in FIG.

FIG. 9 shows a state in which the shield case cover 210 is removed from the body cover 200. As shown in FIG. When the snap-fit connection between the body cover 200 and the shield case cover 210 is released, the plate-like member 310 is pressed by the torsion spring 320 and rotates to a position closing the connection hole 201, as shown in FIG.
As a result, even if the shield case cover 210 is removed from the main body cover 200, the coupling hole 201 for snap-fit coupling is closed by the plate-like member 310, thereby blinding the inside of the main body cover 200 and preventing entry of foreign matter. can be done.

DESCRIPTION OF SYMBOLS 1... Snap-fit connection structure 10... Connection member 11... Main body 12, 212... Cantilever part 13, 213... Claw part 13a, 213a... Engagement surface 20... Cover Coupling member 20a, 200a Coupling surface 21, 201 Coupling hole 30, 300 Pressing mechanism 31, 310 Plate member 31a, 310a Rotating shaft 31b Boss portion 32 , 320 Torsion spring 100 Image forming apparatus 150 Shield case 200 Body cover (member to be coupled)
210: Shield case cover (coupling member)

Claims (5)

A snap-fit connection structure in which a claw portion formed at the tip of a flexible cantilever portion of a connecting member is elastically engaged with a connecting portion of a member to be connected,
A plate-like member attached to the member to be joined so as to rotate about a rotation shaft and a pressing spring are maintained in a state in which the plate-like member is pressed in a direction to block the connecting portion by the pressing spring. and pressing the claw portion in the direction in which the engaging surface of the claw portion provided on the coupling member extends at the tip portion of the plate-like member, and when the coupling of the claw portion of the coupling member is released, the pressing spring provided with a pressing means for blocking the connecting portion in a state of being pressed against
A snap-fit coupling structure characterized by: The plate-shaped member presses and contacts at an angle of 45 degrees or less with respect to the insertion direction of the cantilever portion in a state in which the claw portion is pressed in the direction in which the engaging surface of the claw portion extends.
The snap-fit connection structure according to claim 1 , characterized in that: The pressing force of the pressing spring is greater than the elastic force acting on the cantilever beam portion in the direction in which the claw portion separates from the coupling portion of the member to be coupled when the cantilever beam portion is inserted into the opening. too big,
The snap-fit engagement structure according to claim 2 , characterized in that: The pressure spring is a torsion spring disposed so as to sandwich a portion fixed to the member to be joined and a portion of the plate-shaped member between two arms,
The snap-fit connection structure according to any one of claims 1 to 3 , characterized in that: an image forming means for forming an image on a recording medium;
A cover member comprising the snap-fit coupling structure according to any one of claims 1 to 4 and covering the image forming means,
An image forming apparatus characterized by:

Images