The invention relates to a grounding wheel unfolding and retracting device of a ladder car.Including a ladder car equipped with a wheel frame,One grounding wheel group,The wheel is mounted on one end of the ladder car.The grounding wheel group is slidably arranged at the bottom side of the wheel frame；A connecting rod device comprises a driven shaft,A driving shaft and a connecting rod,The driven shaft is pivoted on the wheel frame and is combined with the grounding wheel group.The driving shaft is arranged on the ladder car and is respectively provided with a wheel swing at both ends and each end is combined with a second grounding wheel.The connecting rod is connected with the driven shaft and the driving shaft.And an electric cylinder drives the driving shaft to swing the second grounding wheel.And the second grounding wheel is synchronously driven by the driven shaft linked by the connecting rod.Make the grounding wheel group and the second grounding wheel protrude downward on the outer side of the track group to support the vehicle body for grounding.It can greatly improve the stability and smoothness of ladder car.本創作一種爬梯車之接地輪展收裝置，包括一爬梯車設有一輪架、一接地輪組，該輪架設於爬梯車一端，該接地輪組滑設於輪架底側；一連桿裝置包含一從動轉軸、一驅動轉軸以及一連桿，該從動轉軸樞設於輪架上且與該接地輪組連動組合，該驅動轉軸設於爬梯車並在兩端分別設有一輪擺件且各結合有一第二接地輪，該連桿連結該從動轉軸與驅動轉軸；以及一電動缸帶動該驅動轉軸而擺動第二接地輪，且透過連桿連動從動轉軸而同步帶動第二接地輪，使接地輪組與第二接地輪向下凸出於履帶組外側支撐車體接地行走，能大幅提高爬梯車行走的穩定性與順暢性。
