Positioning apparatus and image forming apparatus

1. A positioning apparatus comprising:

an apparatus body;

a draw-out portion configured to be drawn out from and attached to the apparatus body; and

a positioning mechanism configured to position the draw-out portion at an attachment position with respect to the apparatus body, the positioning mechanism including:

a first engaging portion provided in one of the apparatus body and the draw-out portion; and

a first engaged portion provided in the other one of the apparatus body and the draw-out portion and configured to determine a position of the draw-out portion in an attachment direction by engaging with the first engaging portion, the first engaged portion having an inclined surface and a positioning surface, the inclined surface being configured to contact the first engaging portion, the positioning surface being configured to position the draw-out portion in the attachment direction at the attachment position,

wherein the inclined surface is inclined downward toward a downstream side in the attachment direction and causes a component force in the attachment direction to act on the draw-out portion on a basis of a weight of the draw-out portion such that the positioning surface is pressed against the first engaging portion in a state in which the inclined surface contacts the first engaging portion.

2. The positioning apparatus according to claim 1 , wherein the other one of the apparatus body and the draw-out portion further includes a sliding surface that is inclined upward toward the downstream side in the attachment direction and that slides on the first engaging portion in attachment of the draw-out portion to the apparatus body, and

wherein the sliding surface is arranged such that the sliding surface slides on the first engaging portion after the inclined surface slides on the first engaging portion when the draw-out portion is drawn out.

3. The positioning apparatus according to claim 2 , wherein the positioning surface and the sliding surface are formed to be continuous from the inclined surface.

4. The positioning apparatus according to claim 1 , wherein the positioning mechanism further includes:

a second engaging portion provided in one of the apparatus body and the draw-out portion; and

a second engaged portion provided in the other one of the apparatus body and the draw-out portion and configured to position the draw-out portion in a direction perpendicular to the attachment direction by engaging with the second engaging portion.

5. The positioning apparatus according to claim 1 , wherein the first engaging portion comprises a shaft having a circular shape in a section view.

6. The positioning apparatus according to claim 1 , wherein the first engaging portion is provided in the apparatus body and comprises a shaft,

wherein the first engaged portion is provided in the draw-out portion, and

wherein the draw-out portion includes a contact portion configured to come into contact with a lower portion of the shaft to regulate deformation of the shaft in a gravity direction.

7. The positioning apparatus according to claim 6 , wherein the draw-out portion comprises a third engaged portion provided at a position different from the first engaged portion in an axial direction of the shaft and configured to determine the position of the draw-out portion in the attachment direction by engaging with the first engaging portion,

wherein the apparatus body includes a first support portion and a second support portion that support the shaft, the first support portion and the second support portion being arranged in the axial direction with an interval therebetween,

wherein the first engaged portion and the third engaged portion are provided between the first support portion and the second support portion in the axial direction, and

wherein the contact portion is provided between the first engaged portion and the third engaged portion in the axial direction.

8. The positioning apparatus according to claim 7 , wherein the contact portion is provided at a center portion between the first engaged portion and the third engaged portion in the axial direction.

9. The positioning apparatus according to claim 1 , further comprising:

a door member openable and closeable with respect to the apparatus body; and

a first pressing unit configured to press the draw-out portion in the attachment direction when the draw-out portion is positioned at the attachment position and the door member is closed with respect to the apparatus body, the first pressing unit being disposed on a lower side of the draw-out portion.

10. The positioning apparatus according to claim 9 , further comprising a second pressing unit configured to press the draw-out portion downward in a state in which the door member is closed with respect to the apparatus body, the second pressing unit being disposed on an upper side of the draw-out portion.

11. The positioning apparatus according to claim 1 , wherein the draw-out portion holds a unit comprising a photosensitive member configured to bear a toner image.

12. The positioning apparatus according to claim 1 , wherein the draw-out portion holds a unit configured to accommodate a developer.

13. The positioning apparatus according to claim 1 , wherein the first engaging portion includes a shaft configured to slide on the inclined surface and to abut against the positioning surface, and

the first engaged portion is a groove having the inclined surface and the positioning surface.

14. The positioning apparatus according to claim 1 , wherein the first engaging portion is provided in the apparatus body, and

the first engaged portion is provided in the draw-out portion.

15. The positioning apparatus according to claim 4 , wherein the first engaging portion includes a first shaft configured to slide on the inclined surface and to abut against the positioning surface,

the first engaged portion is a first groove having the inclined surface and the positioning surface,

the second engaged portion is provided on the draw-out portion and includes a second shaft, and

the second engaging portion is provided on the apparatus body and is a second groove.

16. The positioning apparatus according to claim 4 , wherein the second engaging portion and the second engaged portion are disposed more upstream than the first engaging portion and the first engaged portion in the attachment direction in a case where the draw-out portion is at the attachment position.

17. The positioning apparatus according to claim 4 , wherein the second engaging portion positions the draw-out portion in a vertical direction by nipping the second engaged portion in the vertical direction.

18. An image forming apparatus configured to form an image on a sheet, the image forming apparatus comprising:

an apparatus body;

a draw-out portion configured to be drawn out from and attached to the apparatus body; and

a positioning mechanism configured to position the draw-out portion at an attachment position with respect to the apparatus body, the positioning mechanism including:

a first engaging portion provided in one of the apparatus body and the draw-out portion; and

a first engaged portion provided in the other one of the apparatus body and the draw-out portion and configured to determine a position of the draw-out portion in an attachment direction by engaging with the first engaging portion, the first engaged portion having an inclined surface and a positioning surface, the inclined surface being configured to contact the first engaging portion, the positioning surface being configured to position the draw-out portion in the attachment direction at the attachment position,

wherein the inclined surface is inclined downward toward a downstream side in the attachment direction and causes a component force in the attachment direction to act on the draw-out portion on a basis of a weight of the draw-out portion such that the positioning surface is pressed against the first engaging portion in a state in which the inclined surface contacts the first engaging portion.

19. The image forming apparatus according to claim 18 , wherein the other one of the apparatus body and the draw-out portion further includes a sliding surface that is inclined upward toward the downstream side in the attachment direction and that slides on the first engaging portion in attachment of the draw-out portion to the apparatus body, and

wherein the sliding surface is arranged such that the sliding surface slides on the first engaging portion after the inclined surface slides on the first engaging portion when the draw-out portion is drawn out.

20. The image forming apparatus according to claim 18 ,

wherein the first engaging portion is provided in the apparatus body, and includes a first shaft configured to slide on the inclined surface and to abut against the positioning surface,

the first engaged portion is provided in the draw-out portion, and is a first groove having the inclined surface and the positioning surface.