validate 限制表单提交的内容 302

我想用validate来限制用户不能输入空白的内容，搜索的字节，但是写了以后，已请求浏览器不停的连续发请求，请求返回302，然后最后提示重置太多，代码如下：

blade

@include('common._errors')
.
.
.
<form action="{{ route('search.result') }}" method="POST" class="d-flex flex-row justify-content-between  align-items-center">
    @csrf
    <input type="search" name="keyword" value="{{ $keyword }}">
</form>

controller

public function result(Request $request)
    {
        $this->validate($Request, [
            'keyword' => 'required|min:2|max:10',
        ],
        [
            'keyword.required' => '关键词不能为空',
            'keyword.min' => '搜索关键词至少需要2个字',
            'keyword.max' => '搜索关键词2个字',
        ]);

        $keyword = $request['keyword'];

        $articles = DB::table('articles')->where('title','like','%'. $keyword .'%')->paginate(7);

        if ($request->ajax()) {
            $view = view('mobile.layouts._article_search_list_ajax',compact('articles'))->render();
            return response()->json(['html'=>$view]);
        }

        return view('mobile.search.result', compact('articles','keyword'));
    }