How to schedule event in my wordpress plugin : wp_schedule_event

HI,
I am trying to schedule event in my wordpress plugin, but this doesn’t work. I have tried this :

register_activation_hook(__FILE__, 'my_activation');
add_action('my_hourly_event', 'do_this_hourly');

function my_activation() {
	//create dable for data sync
	plugin_create_table() ;

	wp_schedule_event( current_time( 'timestamp' ), 'hourly', 'my_hourly_event');
	global $wpdb ;
	$wpdb->insert('afn_test_cron',
	array(	'chaine'=>'activation hook'
	)
	);
}

function do_this_hourly() {
	global $wpdb ;
	$wpdb->insert('afn_test_cron',
	array(	'chaine'=>'cron'
	)
	);
}

register_deactivation_hook(__FILE__, 'my_deactivation');

function my_deactivation() {
	wp_clear_scheduled_hook('my_hourly_event');
	global $wpdb ;
	$wpdb->insert('afn_test_cron',
	array(	'chaine'=>'deactivation hook'
	)
	);

This doesn’t work, I have got not error.
Does anybody can help me ?
Thanks,
greetings.Ben