Water-Cooled Engine and Cylinder Block Thereof

Abstract

A cylinder block has a cylinder bore and a water jacket provided about the cylinder bore. The cylinder block is divided at the water jacket into a cylinder liner portion and a cylinder outer wall portion. The cylinder liner portion has a wall defining the cylinder bore. The cylinder outer wall portion surrounds the wall of the cylinder liner portion, thereby defining the water jacket between the cylinder outer wall portion and the wall of the cylinder liner portion. The cylinder liner portion includes an upper deck portion integrally formed with the cylinder liner portion. The upper deck portion contacts the cylinder head assembled to the cylinder block. The cylinder outer wall portion has a top surface that functions as a receiving surface that contacts and supports the upper deck portion.

1 . A water-cooled engine, comprising:
 a cylinder block having a cylinder bore and a water jacket provided about the cylinder bore; and   a cylinder head assembled to the cylinder block, the water-cooled engine being characterized in that:   the cylinder block is divided at the water jacket into a cylinder liner portion and a cylinder outer wall portion, wherein the cylinder liner portion has a wall defining the cylinder bore, and wherein the cylinder outer wall portion surrounds the wall of the cylinder liner portion, thereby defining the water jacket between the cylinder outer wall portion and the wall of the cylinder liner portion, and   wherein the cylinder liner portion includes an upper deck portion integrally formed with the cylinder liner portion, the upper deck portion contacting the cylinder head assembled to the cylinder block, and wherein the cylinder outer wall portion has a top surface that functions as a receiving surface, the receiving surface contacting and supporting the upper deck portion.   
   
   
       2 . The water-cooled engine according to  claim 1 , characterized in that the cylinder outer wall portion includes a support portion integrally formed with the cylinder outer wall portion, the support portion supporting a lower portion of the cylinder liner portion. 
   
   
       3 . The water-cooled engine according to  claim 2 , characterized in that the support portion has a support surface that contacts and supports a lower end of the cylinder liner portion. 
   
   
       4 . The water-cooled engine according to  claim 2 , characterized in that the support portion has a support surface that contacts and supports the wall of the cylinder liner portion. 
   
   
       5 . The water-cooled engine according to any one of  claims 1  to  4 , characterized in that the cylinder block includes a crankcase portion that is integrally formed with the cylinder outer wall portion. 
   
   
       6 . The water-cooled engine according to any one of  claims 1  to  5 , characterized in that the upper deck portion has a through hole that connects a fluid passage formed in the cylinder head with a fluid passage formed in the cylinder outer wall portion. 
   
   
       7 . The water-cooled engine according to any one of  claims 1  to  6 , characterized in that, in a state where the upper deck portion is held between a bottom surface of the cylinder head and the receiving surface, the cylinder head and the cylinder outer wall portion are fastened to each other such that the cylinder block is assembled to the cylinder head. 
   
   
       8 . A cylinder block of a water-cooled engine, wherein the cylinder block has a cylinder bore and a water jacket provided about the cylinder bore, and is assembled to a cylinder head, the cylinder block being characterized in that:
 the cylinder block is divided at the water jacket into a cylinder liner portion and a cylinder outer wall portion, wherein the cylinder liner portion has a wall defining the cylinder bore, and wherein the cylinder outer wall portion surrounds the wall of the cylinder liner portion, thereby defining the water jacket between the cylinder outer wall portion and the wall of the cylinder liner portion, and   wherein the cylinder liner portion includes a substantially planar upper deck portion integrally formed with the cylinder liner portion, the upper deck portion forming a top surface of the cylinder block, and wherein the cylinder outer wall portion has a top surface that functions as a receiving surface, the receiving surface contacting and supporting the upper deck portion.   
   
   
       9 . The cylinder block according to  claim 8 , characterized in that the cylinder outer wall portion includes a support portion integrally formed with the cylinder outer wall portion, the support portion supporting a lower portion of the cylinder liner portion. 
   
   
       10 . The cylinder block according to  claim 9 , characterized in that the support portion has a support surface that contacts and supports a lower end of the cylinder liner portion. 
   
   
       11 . The cylinder block according to  claim 9 , characterized in that the support portion has a support surface that contacts and supports the wall of the cylinder liner portion. 
   
   
       12 . The cylinder block according to any one of  claims 8  to  11 , characterized by a crankcase portion that is integrally formed with the cylinder outer wall portion. 
   
   
       13 . The cylinder block according to any one of  claims 8  to  12 , characterized in that the upper deck portion has a through hole that communicates with a fluid passage formed in the cylinder outer wall portion. 
   
   
       14 . The cylinder block according to any one of  claims 8  to  13 , characterized in that the receiving surface of the cylinder outer wall portion has a bolt receiving hole to which a head bolt is threaded, and the upper deck portion has a bolt through hole through which the head bolt is passed.