PHP SOAP发送struct请求

I trying to get response from SOAP service, I have this in my XML file:

<xs:complexType name="GetInsuranceDataF">
    <xs:sequence>
        <xs:element name="req" type="tns:request" minOccurs="0"/>
    </xs:sequence>
</xs:complexType>
<xs:complexType name="request">
    <xs:sequence>
        <xs:element name="lbo" type="xs:string" minOccurs="0"/>
        <xs:element name="zk" type="xs:string" minOccurs="0"/>
    </xs:sequence>
</xs:complexType>

I try to send data on two ways:

class Request {
    public $lbo;
    public $zk;
}

$request = new Request();
$request->lbo = '13900140107';
$request->zk = '20024179770';
$search = array('req' => $request);

and:

$search = array('req' => array('lbo' => '13900140107', 'zk' => '20024179770'));

but this not working, can someone help me with this?