Sheet conveyance apparatus and image forming apparatus

A sheet conveyance apparatus comprising:

• a first conveying rotary member pair configured to nip and convey a sheet;
• an abutment portion arranged on one side in a width direction orthogonal to a sheet conveyance direction with respect to the sheet being conveyed;
• a first skewing rotary member pair arranged downstream of the first conveying rotary member pair in the sheet conveyance direction and configured to obliquely convey the sheet toward the abutment portion;
• a second skewing rotary member pair arranged downstream of the first conveying rotary member pair in the sheet conveyance direction and configured to obliquely convey the sheet toward the abutment portion;
• a switching mechanism configured to switch the second skewing rotary member pair between a nipping state in which the sheet is nipped and conveyed and a non-nipping state in which the nipping of the sheet is released;
• and
• a control unit configured to control the switching mechanism,
• wherein the control unit is configured to execute
• a first mode of controlling the second skewing rotary member pair to be in the nipping state in a sheet oblique conveyance state which is a state from when the first skewing rotary member pair starts an oblique conveyance of the sheet having been conveyed by the first conveying rotary member pair until an edge portion in the width direction of the sheet abuts the abutment portion, and
• a second mode of controlling the second skewing rotary member pair to be in the non-nipping state in the sheet oblique conveyance state.