Being only the need to submit the form, you could use ajax, but it does not seem to me the case, yet there is a new Html5 attribute that can help you, is the form="..." and create a hidden form (so you won’t need javascript):
<!--// formulário oculto -->
<form action="rota" method="POST" id="meuformulario">
  <input type="hidden" name="chave1" value="1">
  <input type="hidden" name="chave2" value="2">
  <input type="hidden" name="chave3" value="3">
</form>
...
<p>....</p>
...    
<button type="submit" form="meuformulario" value="Chamar">Chamar (trigger)</button>
Source: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/button
In addition it is still possible to control the form with other attributes by <button>:
formaction exchange form action pointed by attribute form=""
 
formenctype this attribute changes the ecntype form pointed by the attribute form="", values that can be used:
application/x-www-form-urlencoded 
multipart/form-data 
text/plain 
 
formmethod exchange the method of <form> pointed by the attribute form=""
 
formnovalidate exchange the value of <form novalidate=""> pointed by the attribute form="" is a Boleano value.
 
formtarget exchange the target of the window instance you want the request to be made, examples of values accepted:
_self 
_blank 
_parent 
_top 
 
Example:
<button formaction="/pagina" formenctype="multipart/form-data" formmethod="POST" formtarget="_blank">