Why did not save form data with validation in the Controller in Laravel 5.6?

am working with Laravel 5.6 and MySQL DB. I have data store function with validation in controller like following,

public function store(Request $request)
    {
        $this->validate($request, [
            'provincename'     => 'required|min:3',
            'districtname'    => 'required',
            'townname'    => 'required',
            'brandname'    => 'required',
            'modelname'    => 'required',
            'year'    => 'required',
            'condition'    => 'required',
            'milage'    => 'required',
            'data'    => 'required',
            'price'    => 'required',
            'telephone'    => 'required',
            'categoryname'    => 'required',
            'tramsmission'    => 'required',
            'fuel'    => 'required',
            'enginecap'   => 'required'
        ]);

My Problem is in above controller function store data is saving to data table with out controller validation part. but with validation codes it is not saving data to the table. no any error message displaying also. how can fix this problem? full Controller store function

public function store(Request $request)
    {
        $this->validate($request, [
            'provincename'     => 'required|min:3',
            'districtname'    => 'required',
            'townname'    => 'required',
            'brandname'    => 'required',
            'modelname'    => 'required',
            'year'    => 'required',
            'condition'    => 'required',
            'milage'    => 'required',
            'data'    => 'required',
            'price'    => 'required',
            'telephone'    => 'required',
            'categoryname'    => 'required',
            'tramsmission'    => 'required',
            'fuel'    => 'required',
            'enginecap'   => 'required'
        ]);
        $vehicle = new Vehicle;

        $vehicle->provincename = $request->input('provincename');
        $vehicle->districtname = $request->input('districtname');
        $vehicle->townname = $request->input('townname');
        $vehicle->brandname = $request->input('brandname');
        $vehicle->modelname = $request->input('modelname');
        $vehicle->modelyear = $request->input('year');
        $vehicle->condition = $request->input('condition');
        $vehicle->milage = $request->input('milage');
        $vehicle->detail = $request->input('data');
        $vehicle->price = $request->input('price');
        $vehicle->telephone = $request->input('telephone');
        $vehicle->categoryname =  $request->input('categoryname');
        $vehicle->transmission = $request->input('transmission');
        $vehicle->fueltype = $request->input('fuel');
        $vehicle->enginecapacity = $request->input('enginecap');

        $vehicle->user_id = Auth::user()->id;

        $vehicle->save();

$photos = $request->file('files');

        if (!is_array($photos)) {
            $photos = [$photos];
        }

        if (!is_dir($this->photos_path)) {
            mkdir($this->photos_path, 0777);
        }

        for ($i = 0; $i < count($photos); $i++) {
            $photo = $photos[$i];
            $name = sha1(date('YmdHis') . str_random(30));
            $save_name = $name . '.' . $photo->getClientOriginalExtension();
            $resize_name = $name . str_random(2) . '.' . $photo->getClientOriginalExtension();

            Image::make($photo)
                ->resize(250, null, function ($constraints) {
                    $constraints->aspectRatio();
                })
                ->save($this->photos_path . '/' . $resize_name);

            $photo->move($this->photos_path, $save_name);

            $upload = new Upload();
            $upload->filename = $save_name;
            $upload->resized_name = $resize_name;
            $upload->original_name = basename($photo->getClientOriginalName());
            $upload->vehicle_id = $vehicle->id;
            $upload->save();
        }
    }

via Chebli Mohamed