使用php中的Curl将文件下载到特定文件夹

Question

I have a Google Drive File Url suppose for eg.

https://doc-0c-90-docs.googleusercontent.com/docs/securesc/rgh255lj001rts71cq6a0d0fmikln8fe/gg1vds4tn8h88pushsj7s1c1qvsb8nk3/1442404800000/16565899266202741945/16565899266202741945/0B86G8IQ4Uf9ATk5wRW9pdXN6OFE?e=download&gd=true

I want to download it to a specific folder for that i am using curl

function pickerCallback(data) {
     if (data[google.picker.Response.ACTION] == google.picker.Action.PICKED) {
        var doc = data[google.picker.Response.DOCUMENTS][0];
        var fileId=doc[google.picker.Document.ID];

              $.ajax({
                type: "POST",
                url: "files/sample.php",
                data: { file_id:fileId,token:oauthToken },
                success: function(data)
                {   

                }
            });
         }
}

sample.php

$upload_path='folder_path';
$fileId = $_POST['file_id'];
$oAuthToken = $_POST['token'];

$getUrl = 'https://www.googleapis.com/drive/v2/files/'. $fileId .'?alt=media';
$authHeader = 'Authorization: Bearer ' . $oAuthToken ;

function get_data($url) {
    $ch = curl_init();
    $timeout = 5;
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
    $data = curl_exec($ch);
    curl_close($ch);
    return $data;
}

$returned_content = get_data($getUrl);
file_put_contents($upload_path.'/'."55dad26bf4165.jpg", $returned_content); 

this is the name of the file that i am downloading 55dad26bf4165.jpg, but it gives following error :

string(379)" { "error"; { "errors":[{ "domain":"usageLimits","reason":dailyLimitExceededUnreg", message:Daily Limit for Unauthenticated Use Exceeded. Continue use requires signup.". "extendedHelp":"https://code.google.com/apisconsole" }], "code":403, "message":"Daily Limit for Unauthenticated Use Exceeded. Continued use requires signup."}}"

Please help why this error is occuring.