Patent Publication Number: US-10307771-B2

Title: Lance nozzle and excess sprayed coating removal device including the same

Description:
BACKGROUND 
     1. Field of the Invention 
     The present invention relates to a lance nozzle and an excess sprayed coating removal device including the same that are appropriate for, for example, removing an excess sprayed coating adhering inside a crank chamber of an engine. 
     2. Description of the Related Art 
     There have been known aluminum cylinder blocks in which an iron-based sprayed coating is formed in a cylinder bore. When the sprayed coating is formed in the cylinder bore, the sprayed coating also adheres to the interior of a crank chamber. Since the sprayed coating adhering to the interior of the crank chamber is unnecessary, it is necessary to remove the sprayed coating (hereinafter referred to as the excess sprayed coating). A method for removing excess sprayed coatings adhering to the interior of the crank chamber by using the water jet from a water injection nozzle is disclosed for example in Japanese Unexamined Patent Application Publication No. 2008-303439. 
     The water injection nozzle disclosed in the Japanese Unexamined Patent Application Publication No. 2008-303439 is equipped with a first injection port of low-pressure injection, the first injection port provided on the leading end side thereof and a second injection port of high-pressure injection. This water injection nozzle is configured such that a water curtain is formed by the low-pressure injection from the first injection port and the excess sprayed coatings are removed by the high-pressure injection from the second injection port. According to the Japanese Unexamined Patent Application Publication No. 2008-303439, the water curtain formed by the low-pressure injection functions to inhibit the high-pressure injection water from being directed toward a sprayed coating formed in the cylinder bore, thereby preventing the sprayed coating from peeling off. 
     SUMMARY 
     A crank chamber of a cylinder block of a multi-cylinder engine includes a partition wall that separates each cylinder and supports a journal of a crankshaft. The partition wall includes various holes such as a communication hole and a journal hole. The excess sprayed coating also adheres on the inner surface of these holes. Hence, the excess sprayed coatings adhering on the inner surface of the various holes need to be removed. However, the method for removing the excess sprayed coating according to Japanese Unexamined Patent Application Publication No. 2008-303439 has a following problem: the configuration where the high pressure water is injected in a direction perpendicular to an axial direction of the nozzle (horizontal direction) makes it difficult to sufficiently remove the excess sprayed coating adhering on a surface in an approximately vertical direction with respect to a center axis of the cylinder bore, for example, the inner surface of the communication hole and the journal hole. 
     The present invention has been made to solve the above-described problem, and it is an object of the present invention to provide a lance nozzle and an excess sprayed coating removal device including the lance nozzle that ensures to more certainly remove an excess sprayed coating, for example, adhering on an inner surface of a hole formed in a crank chamber of a cylinder block. 
     To achieve the above-mentioned object, the representative present invention is a lance nozzle injecting fluid that includes a shaft body, a first nozzle hole, and a second nozzle hole. The shaft body internally includes a flow path of the fluid. The first nozzle hole is disposed on a leading end side of the shaft body, and generates a first jet in a first injecting direction inclining to a base end side of the shaft body with respect to a direction perpendicular to an axial direction of the shaft body. The second nozzle hole is disposed on a base end side of the first nozzle hole in the shaft body, and generates a second jet in a second injecting direction inclining to a leading end side of the shaft body with respect to a direction perpendicular to an axial direction of the shaft body. 
     According to the present invention, for example, excess sprayed coatings adhering on an inner surface of a hole disposed in a crank chamber of a cylinder block is removed with more certainty. Note that, descriptions of the following embodiments reveal problems, configurations, and effects other than the above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments of the present embodiments are described with reference to the following figures, wherein like reference signs refer to like parts throughout the various views unless otherwise specified. 
         FIG. 1  is a cross-sectional view illustrating an overall configuration of an excess sprayed coating removal device according to a first embodiment, 
         FIG. 2  is a schematic diagram illustrating a design limit of a lance nozzle indicated in  FIG. 1 , 
         FIG. 3  is a schematic diagram illustrating the design limit of the lance nozzle indicated in  FIG. 1 , 
         FIG. 4  is a cross-sectional view illustrating an overall configuration of an excess sprayed coating removal device according to a second embodiment, 
         FIG. 5  is a cross-sectional view taken along a line V-V in  FIG. 4 , 
         FIG. 6  is a cross-sectional view taken along a line VI-VI in  FIG. 4 , 
         FIG. 7  is a schematic diagram illustrating a method for using the excess sprayed coating removal device according to the second embodiment, and 
         FIG. 8  is a cross-sectional view illustrating an overall configuration of an excess sprayed coating removal device according to a third embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     (First Embodiment) 
     The embodiments according to the present invention will be described in detail in accordance with the drawings. The first embodiment indicates an exemplary case where an excess coating adhering inside a crank chamber of an in-line multi-cylinder engine is removed.  FIG. 1  is a cross-sectional view illustrating an excess sprayed coating removal device  10  including a lance nozzle  30  according to the embodiment, taken along a cross-sectional surface passing through a rotational axis  22  of the lance nozzle  30  in a state where the excess sprayed coating removal device  10  is inserted into an inverted cylinder block  100 . Note that, in the following description, “leading end side” means the lower side in  FIG. 1 , and “base end side” means the upper side in  FIG. 1 . 
     The excess sprayed coating removal device  10  inserts the lance nozzle  30  into each of spaces (small chambers)  108  partitioned by partition walls  101  in a crank chamber  107 , and removes excess sprayed coatings (not shown) adhering to the crank chamber  107  using jets J 1 , J 2  discharged from nozzle holes  35 , 36  of the lance nozzle  30 . 
     The excess sprayed coating removal device  10  can be applied as part of a turret cleaning device. Cleaning devices, such as disclosed in Japanese Unexamined Patent Application Publication Nos. 2011-230118 and 2015-58479, can be used as the turret cleaning device. 
     The excess sprayed coating removal device  10  is equipped with a turret  11  as a spindle casing which is provided to an orthogonal three-axis moving device (not shown). The orthogonal three-axis moving device is controlled, for example, by a numerical control device. The interior of the turret  11  is provided with a rotatably-supported main spindle  12 . The main spindle  12  is rotated about the rotational axis  22 . A receiving portion  12   a  is provided at the leading end portion of the main spindle  12 . The receiving portion  12   a  is formed in the shape of a U-section groove with its length in a direction to penetrate the drawing sheet. The receiving portion  12   a  is engaged with an engaging portion  16   a  of a nozzle supporting member  16  to be described later, and has the function of integrally rotating the nozzle supporting member  16  and the main spindle  12 . 
     The turret  11  is provided with a cylindrical housing  13  about the rotational axis  22 . The housing  13  is equipped with a cylindrical hole  13   b . Bearings  14 , packing  15  to be described later, and the nozzle supporting member  16  are inserted in the cylindrical hole  13   b . The nozzle supporting member  16  is rotatably supported in the housing  13  by the bearings  14 . 
     The nozzle supporting member  16  is composed of the engaging portion  16   a , a shaft  16   b , and a flange  16   c  of different diameters coaxially integrally provided, and is generally formed in an approximately cylindrical shape. The engaging portion  16   a  is double-chamfered or a key, both sides thereof being formed flat. Both flat surfaces of the engaging portion  16   a  are caught in the receiving portion  12   a  with a slight clearance therebetween. Thus, the nozzle supporting member  16  rotates in response to the rotation of the main spindle  12 . The flange  16   c  is formed in a disk-like shape and has a receiving portion  16   d  and a threaded hole  16   e . The receiving portion  16   d  is a cylindrical hole which fits a protruding portion  33   b  of the lance nozzle  30 . 
     The cylindrical hole  13   b  is provided with the packing  15 . The packing  15  is formed in a hollow cylindrical shape, and a circumferential groove  15   a  with rectangular section is provided in the center of the outer circumference thereof. A circumferential groove  15   c  with rectangular section is also provided in the center of the inner circumference of the packing  15 . The packing  15  is provided with at least one through-hole  15   b  that provides communication between the circumferential groove  15   a  and the circumferential groove  15   c . The packing  15  provides a seal between the housing  13  and the nozzle supporting member  16 , and provides communication between flow paths  19  and  24  to be described later. The packing  15  can be made of engineering plastics or super engineering plastics. 
     A cleaning liquid supplying device  17  supplies cleaning liquid in the range of 10 to 80 MPa, preferably in the range of 30 to 50 MPa. Options of the cleaning liquid supplying device  17  can include a piston pump. The cleaning liquid supplying device  17  discharges the cleaning liquid retained in a cleaning liquid tank not shown. Alkaline or neutral water-soluble cleaning liquid or oily cleaning liquid is available as the cleaning liquid. 
     A valve  18  switches between the transmission and the interruption of the cleaning liquid from the cleaning liquid supplying device  17  to the turret  11 . For example, a solenoid-operated cylinder valve can be used as the valve  18 . The opening/closing of the valve  18  is automatically controlled, for example, by a numerical control device. The valve  18  can be configured as a flow path switching valve that returns the cleaning liquid to the cleaning liquid tank during the interruption of the cleaning liquid. 
     The flow path  19  is provided through the turret  11  and the housing  13 . The flow path  19  is provided so as to communicate with the circumferential groove  15   a  of the packing  15 . The flow path  24  is formed in T shape, and provided inside the nozzle supporting member  16 . One end of the flow path  24  passes through the receiving portion  16   d . The other end of the flow path  24  opens into the circumferential groove  15   c  of the packing  15 . The flow path  19  and the flow path  24  are connected through the circumferential grooves  15   a  and  15   c  and the through-hole  15   b . The circumferential grooves  15   a  and  15   c  circumferentially distribute the cleaning liquid. 
     The lance nozzle  30  is equipped with a flange  33   a  and a shaft body  33 . The flange  33   a  is formed in a disk-like shape. The flange  33   a  is provided with through-holes  33   c  and the protruding portion  33   b . The lance nozzle  30  is fixed to the flange  16   c  of the nozzle supporting member  16  by bolts  21  inserted in the through-holes  33   c . The protruding portion  33   b  provided on the flange  33   a  is fitted and inserted in the receiving portion  16   d  of the nozzle supporting member  16 . When the protruding portion  33   b  is fitted into the receiving portion  16   d  and the flange  33   a  and the flange  16   c  are brought into abutting relation, the lance nozzle  30  is accurately fixed to the nozzle supporting member  16 . 
     It should be noted that the lance nozzle  30  can be configured in the shape of a rod without the flange  33   a  in place of the above-described configuration. In this case, the nozzle supporting member  16  is equipped with a collet in place of the flange  16   c . Furthermore, the rod-shaped lance nozzle  30  may be fixed to the nozzle supporting member  16  by the collet. 
     The shaft body  33  is a rod-shaped body extending along the rotational axis  22 , and preferably is formed in a spindly column shape. A flow path  34  is provided in the center of the shaft body  33 . The flow path  34  extends to the vicinity of the leading end of the shaft body  33 . The flow path  34  is connected to the flow path  24  of the nozzle supporting member  16 . 
     The shaft body  33  includes a circumferential groove  38  with an approximately V-shaped cross-sectional surface on the leading end portion of the shaft body  33 . Here, the “approximately V-shaped” includes a round bottom face and a flat bottom face. The cross-sectional surface of the circumferential groove  38  is not necessary to be disposed in symmetry with respect to the horizontal line. The circumferential groove  38  includes a nozzle hole  36  (a first nozzle hole) to inject high pressure water on a surface on the leading end side of the circumferential groove  38 . The nozzle hole  36  communicates with the flow path  34 , in which the high pressure water flows, and preferably, the nozzle hole  36  is disposed on slightly base end side with respect to the leading end of the flow path  34 . The nozzle hole  36  injects a jet J 1  (a first jet) toward an injecting direction F 1  (a first injecting direction). The jet J 1  is configured such that a centerline  32  of the jet J 1  intersects with the rotational axis  22  at an intersection point  32   a , and an angle between the centerline  32  and the rotational axis  22  is θ 1 . Hence, the jet J 1  is injected from the nozzle hole  36  toward the base end side inclining by the injection angle of θ 1  from the rotational axis  22 , and appears in a cylindrical shape along the centerline  32 . Preferably, the surface on the leading end side of the circumferential groove  38  is vertically disposed to the centerline  32  of the jet J 1 . Disposing the circumferential groove  38  ensures the lance nozzle  30  to be fabricated easier. Further, the peripheral area of the nozzle hole  36  appears on an approximately plane surface. This ensures the jet J 1  to be rod-shaped with little turbulence. 
     On the other hand, the shaft body  33  includes a circumferential groove  37  with an approximately V-shaped cross-sectional surface on the base end side of the nozzle hole  36  of the shaft body  33 , more specifically, on the generally center part of the shaft body  33 . Here, the “approximately V-shaped” includes a round bottom face and a flat bottom face. The cross-sectional surface of the circumferential groove  37  is not necessary to be disposed in symmetry with respect to the horizontal line. The circumferential groove  37  includes a nozzle hole  35  (a second nozzle hole) to inject high pressure water on a surface on the base end side of the circumferential groove  37 . The nozzle hole  35  communicates with the flow path  34 , in which the high pressure water flows. The nozzle hole  35  injects a jet J 2  (a second jet) toward an injecting direction F 2  (a second injecting direction). The jet J 2  is configured such that a centerline  31  of the jet J 2  intersects with the rotational axis  22  at an intersection point  31   a , and an angle between the centerline  31  and the rotational axis  22  is θ 2 . Hence, the jet J 2  is injected from the nozzle hole  35  toward the leading end side inclining by the injection angle of θ 2  from the rotational axis  22 , and appears in a cylindrical shape along the centerline  31 . Preferably, the surface on the base end side of the circumferential groove  37  is vertically disposed to the centerline  31  of the jet J 2 . Disposing the circumferential groove  37  ensures the lance nozzle  30  to be fabricated easier. Further, the peripheral area of the nozzle hole  35  appears on an approximately plane. This ensures the jet J 2  to be rod-shaped with little turbulence. 
     Here, the centerline  31  and the centerline  32  are disposed on an identical plane, and faces the opposite direction one another. Additionally, while, in this embodiment, the relation between the angles θ 1  and θ 2  is θ 1 &gt;θ 2 , the relation may be θ 1 =θ 2 , or θ 1 &lt;θ 2 . The angles θ 1  and θ 2  can be appropriately configured corresponding to the shape of the crank chamber  107 , the inner diameters of the journal hole  102  and the communication hole  103 , and similar factor. 
     Note that, the cross-sectional shape of the shaft body  33  may be a rectangular and similar shape. In this case, the shaft body  33  is configured such that the center of gravity of the shaft body  33  and the rotational axis  22  are disposed coaxially. Further, the circumferential grooves  37  and  38  may be omitted. Instead of the circumferential grooves  37  and  38 , the shaft body  33  may include cut-out portions configured to appear planes perpendicular to the nozzle holes  35  and  36  (planes perpendicular to the centerlines  31  and  32 ). Note that, each of the centerline  31  and the centerline  32  is not necessary to intersect with the rotational axis  22 . However, the centerline  31  and the centerline  32  are preferred to be disposed on a position in a point symmetry with the rotational axis  22  as the center viewing in the direction of the rotational axis  22 . 
     Next, the method for use of the excess sprayed coating removal device  10  configured in this manner and the advantageous effects thereof will be described. 
     The cylinder block  100  is the cylinder block of the in-line multi-cylinder engine. The cylinder block  100  is installed in an inverted manner with the cylinder head installation surface (not shown) facing downward in the vertical direction. The cylinder block  100  is equipped with the plurality of cylinder bores  104 . The crank chamber  107  is partitioned into the spaces (small chambers)  108  by the partition walls  101  for each of the cylinder bores  104 . The partition walls  101  are each provided with a journal hole  102  and the communication hole  103 . The communication hole  103  is a so-called vent. The cylinder bores  104  of the cylinder block  100  are film-formed with the sprayed coating  105 . At this time, excess sprayed coatings adhere to almost the entire inner surface of the crank chamber  107 . 
     At the time of using the excess sprayed coating removal device  10 , the cleaning liquid supplying device  17  is firstly operated. Then the main spindle  12  is rotated. The nozzle supporting member  16  and the lance nozzle  30  are rotated with the rotation of the main spindle  12 . The rotational axis  22  of the lance nozzle  30  is positioned spacedly above the crank chamber  107  in an extension of the bore center  106  of the cylinder bore  104 . The numerical control device switches the valve  18  to supply cleaning liquid to the turret  11 . The cleaning liquid is supplied to the nozzle holes  35 ,  36  through the valve  18 , the flow path  19 , the flow path  24 , and the flow path  34  from the cleaning liquid supplying device  17 . The cleaning liquid is discharged as the jet J 1  from the nozzle hole  36 , and discharged as the jet J 2  from the nozzle hole  35 . The nozzle hole  35  and the nozzle hole  36  are disposed in the point symmetry with the rotational axis  22  as the center viewing in the direction of the rotational axis  22 . Then, the injection of the jet J 1  and the jet J 2  cancels the reactive force that the shaft body  33  receives. Moving the turret  11  downward along the bore center  106  causes the jet J 2  to collide with the inner surfaces of a skirt  109  and the partition wall  101  that partition the space  108 . This peels off the excess sprayed coatings that adhere on the inner surfaces. 
     Continuously moving the turret  11  downward also causes the jet J 1  to start colliding with the inner surfaces of the skirt  109  and the partition wall  101 . The jet J 2  inclines to the leading end direction of the lance nozzle  30 . Then, the jet J 2  removes the excess sprayed coatings adhering on an inner surface  102   b  of the lower side of the journal hole  102  and an inner surface  103   b  of the lower side (hereinafter referred to as “a lower-side inner surface  103   b ”) of the communication hole  103 . On the other hand, the jet J 1  inclines to the base end direction of the lance nozzle  30 . Then, the jet J 1  removes the excess sprayed coatings adhering on an inner surface  102   a  of the upper side of the journal hole  102  and an inner surface  103   a  of the upper side (hereinafter referred to as “an upper-side inner surface  103   a ”) of the communication hole  103 . The lance nozzle  30  is mostly configured such that, on the position when the jet J 2  passes through the lower-side inner surface  103   b  of the communication hole  103 , the jet J 1  passes through the upper-side inner surface  103   a  of the communication hole  103 . 
     After the excess sprayed coating removal device  10  moved the lance nozzle  30  downward to the extent that the jets J 1  and J 2  do not collide with the cylinder bore  104 , the excess sprayed coating removal device  10  moves the lance nozzle  30  upward. When the lance nozzle  30  is raised to the position before the insertion at the first, the excess sprayed coating removal device  10  determines the position of the lance nozzle  30  to the bore center of a next cylinder bore  104   b . Then, the excess sprayed coating removal device  10  removes the excess sprayed coating adhering in a space  108   b  of the crank chamber  107  as well as the above-described procedure. The excess sprayed coating removal device  10  removes the excess sprayed coating of every space  108  separated by the partition wall  101  of the crank chamber  107 . 
     As described above, the lance nozzle  30  according to the embodiment includes the nozzle hole  36  (the first nozzle hole) that inclines in the base end direction of the lance nozzle  30  on the leading end portion of the lance nozzle  30 , and includes the nozzle hole  35  (the second nozzle hole) that inclines in the leading end direction of the lance nozzle  30  on the intermediate position of the nozzle hole  36  and the base end portion. Hence, when the lance nozzle  30  is inserted from the crank chamber  107  side along the bore center  106 , the jet J 1  (the first jet) generated from the nozzle hole  36  and the jet J 2  (the second jet) generated from the nozzle hole  35  can be disposed to reach an approximately identical height near the partition wall  101 . 
     Then, the jet J 1  and the jet J 2  are inclined in the base end direction (F 1  direction) and the leading end direction (F 2  direction) respectively. This ensures the jets J 1  and J 2  to directly reach the inner surfaces of the journal hole  102  and the communication hole  103  that are disposed on the partition wall  101 . In view of this, the lance nozzle  30  according to the embodiment can effectively remove the excess sprayed coating, which is difficult to be removed by conventional technology, adhering on surfaces facing in the direction approximately perpendicular to the bore center  106  (such as the inner surface of the journal hole  102  and the communication hole  103 ). The crank chamber  107  includes a wall surface where a part adjacent to the cylinder bore  104  is disposed approximately perpendicular to the bore center  106 . The angle θ 2  is a small angle, then, the part adjacent to the cylinder bore  104  in the crank chamber  107  receives the strong jet J 2 . This effectively removes the excess sprayed coating adhering on the part. 
     Further, according to the lance nozzle  30  of the embodiment, the jet J 1  and the jet J 2  reach the approximately identical height near the wall surfaces of the partition wall  101  and the cylinder bore  104 . This ensures the lance nozzle  30  to be deeply inserted. When the lance nozzle  30  is inserted until any one of the jet J 1  and the jet J 2  reaches the position slightly biased to the crank chamber  107  with respect to the upper end of the cylinder bore  104 , the excess sprayed coating adhering on the crank chamber  107  is removed without almost any blind spots. 
     The necessary sprayed coating  105  formed on the cylinder bore  104  is damaged by the jets J 1  and J 2  colliding with the sprayed coating  105 . The nozzle hole  35  of the lance nozzle  30  according to the embodiment is preferred to be disposed with a steep inclination to the extent that the jet J 2  does not pass through the communication hole  103 . This configuration prevents the jet J 2  from passing through the communication hole  103  and entering into next spaces  108   a  and  108   b  from the space  108  where the lance nozzle  30  is inserted. Hence, the jet J 2  is prevented from colliding with the inner surfaces of cylinder bores  104   a  and  104   b  coupled to the spaces  108   a  and  108   b  respectively. This prevents sprayed coatings  105   a  and  105   b  formed on the cylinder bores  104   a  and  104   b  from being damaged. 
     Next, a description will be given of a design limit of the preferred lance nozzle  30  referring to  FIG. 2  and  FIG. 3  in addition to  FIG. 1 .  FIG. 2  and  FIG. 3  are schematic diagrams illustrating the design limit of the lance nozzle illustrated in  FIG. 1 . 
     Referring to  FIG. 1 , the jet J 2  is preferred to be configured not to pass through the communication hole  103 . Preferably, an inclination angle of the nozzle hole  35 , that is, an angle (injection angle) θ 2  formed by the centerline  31  of the jet J 2  and the rotational axis  22  of the shaft body  33  is configured in a range of the following formula. 
     
       
         
           
             
               
                 
                   0 
                   &lt; 
                   
                     θ 
                     2 
                   
                   ≤ 
                   
                     
                       tan 
                       
                         - 
                         1 
                       
                     
                     ⁡ 
                     
                       ( 
                       
                         T 
                         D 
                       
                       ) 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Formula 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     4 
                   
                   ] 
                 
               
             
           
         
       
     
     Where 
     D: representative length (length of a hole along the bore center  106 ) of a hole (such as the journal hole  102  or the communication hole  103 ); and 
     T: representative thickness of the partition wall  101 . 
     If the jet J 2  is configured in a range of the above formula, the jet J 2  does not pass through the hole disposed on the partition wall  101  (such as the journal hole  102  or the communication hole  103 ). Hence, the jet J 2  does not damage the sprayed coatings  105   a  and  105   b  of the cylinder bores  104   a  and  104   b . Note that, the jet J 2  that passes through the journal hole  102  does not damage the sprayed coating  105   b  depending on the pressure and the flow rate of the jet J 2  because the distance between the nozzle hole  35  and the sprayed coating  105   b  is far. In this case, the jet J 2  may pass through the journal hole  102 . 
     The jet J 1  is less likely to damage the necessary sprayed coating because the jet J 1  inclines upward (toward the base end). The jet J 1  is preferred to be configured to reach at least a half of the depth of the partition wall  101  viewing from the space  108 , into which the lance nozzle  30  is inserted. Preferably, an inclination angle of the nozzle hole  36 , that is, an angle (injection angle) θ 1  formed by the centerline  32  of the jet J 1  and the rotational axis  22  of the shaft body  33  is configured in a range of the following formula. 
     
       
         
           
             
               
                 
                   
                     
                       tan 
                       
                         - 
                         1 
                       
                     
                     ⁡ 
                     
                       ( 
                       
                         T 
                         
                           2 
                           ⁢ 
                           D 
                         
                       
                       ) 
                     
                   
                   ≤ 
                   
                     θ 
                     1 
                   
                   &lt; 
                   
                     90 
                     ⁢ 
                     ° 
                   
                 
               
               
                 
                   [ 
                   
                     Formula 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     5 
                   
                   ] 
                 
               
             
           
         
       
     
     Where 
     D: representative length (length of a hole along the bore center  106 ) of a hole (such as the journal hole  102  or the communication hole  103 ); and 
     T: representative thickness of the partition wall  101 . 
     Note that, if it is not necessary to consider that the jet J 2  passes through the journal hole  102 , as D and T, the length relating to the communication hole  103  is available. The same applies to the following description. 
     Referring to  FIG. 2 , a minimum distance L min  between the intersection point  31   a  and the intersection point  32   a  will be described. A fall limit of the turret  11  is a position where the centerline  31  of the jet J 2  reaches the upper end of the cylinder bore  104 . On the position, the jet J 1  is preferred to be configured to remove the excess sprayed coating of the front half of the depth of the upper-side inner surface  103   a  of the communication hole  103 . The preferable L min  is provided by the following formula. 
     
       
         
           
             
               
                 
                   
                     L 
                     min 
                   
                   = 
                   
                     
                       BP 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           1 
                         
                       
                     
                     + 
                     
                       BD 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           2 
                         
                       
                     
                     - 
                     H 
                   
                 
               
               
                 
                   [ 
                   
                     Formula 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     6 
                   
                   ] 
                 
               
             
           
         
       
     
     Where 
     BP: distance of the pitch between the cylinder bores  104 ; 
     BD: diameter of the cylinder bore  104 ; 
     θ 1 : angle formed by the centerline  32  of the jet J 1  and the rotational axis  22  of the shaft body  33 ; 
     θ 2 : angle formed by the centerline  31  of the jet J 2  and the rotational axis  22  of the shaft body  33 ; and 
     H: height from the upper end of the cylinder bore  104  to the upper-side surface of the communication hole  103  disposed on the partition wall  101  in the case where the cylinder block  100  is inverted. 
     Referring to  FIG. 3 , a maximum distance L max  between the intersection point  31   a  and the intersection point  32   a  will be described. The fall limit of the turret  11  is a position where the centerline  32  of the jet J 1  reaches the upper end of the cylinder bore  104 . On the position, the jet J 2  is preferred to be configured to remove the excess sprayed coating of the entire lower-side inner surface  103   b  of the communication hole  103 . The preferable L max  is provided by the following formula. 
     
       
         
           
             
               
                 
                   
                     L 
                     max 
                   
                   = 
                   
                     
                       BD 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           1 
                         
                       
                     
                     + 
                     
                       
                         BP 
                         - 
                         T 
                       
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           2 
                         
                       
                     
                     + 
                     H 
                     - 
                     D 
                   
                 
               
               
                 
                   [ 
                   
                     Formula 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     7 
                   
                   ] 
                 
               
             
           
         
       
     
     Where 
     BD: diameter of the cylinder bore  104 ; 
     BP: distance of the pitch between the cylinder bores  104 ; 
     T: representative thickness of the partition wall  101 ; 
     θ 1 : angle formed by the centerline  32  of the jet J 1  and the rotational axis  22  of the shaft body  33 ; 
     θ 2 : angle formed by the centerline  31  of the jet J 2  and the rotational axis  22  of the shaft body  33 ; 
     H: height from the upper end of the cylinder bore  104  to the upper-side surface of the communication hole  103  disposed on the partition wall  101  in the case where the cylinder block  100  is inverted; and 
     D: representative length (length of a hole along the bore center  106 ) of a hole (such as the journal hole  102  or the communication hole  103 ). 
     Accordingly, a distance L (distance between the intersection point  31   a  and the intersection point  32   a ) between the nozzle hole  35  and the nozzle hole  36  in an axial direction of the shaft body  33  is preferred to be configured in a range of the following formula. 
     
       
         
           
             
               
                 
                   
                     
                       BP 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           1 
                         
                       
                     
                     + 
                     
                       BD 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           2 
                         
                       
                     
                     - 
                     H 
                   
                   ≤ 
                   L 
                   ≤ 
                   
                     
                       BD 
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           1 
                         
                       
                     
                     + 
                     
                       
                         BP 
                         - 
                         T 
                       
                       
                         2 
                         ⁢ 
                         
                           tanθ 
                           2 
                         
                       
                     
                     + 
                     H 
                     - 
                     D 
                   
                 
               
               
                 
                   [ 
                   
                     Formula 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     8 
                   
                   ] 
                 
               
             
           
         
       
     
     Where 
     BP: distance of the pitch between the cylinder bores  104 ; 
     BD: diameter of the cylinder bore  104 ; 
     θ 1 : angle formed by the centerline  32  of the jet J 1  and the rotational axis  22  of the shaft body  33 ; 
     θ 2 : angle formed by the centerline  31  of the jet J 2  and the rotational axis  22  of the shaft body  33 ; 
     T: representative thickness of the partition wall  101 ; 
     H: height from the upper end of the cylinder bore  104  to the upper-side inner surface of the communication hole  103  disposed on the partition wall  101  in the case where the cylinder block  100  is inverted; and 
     D: representative length (length of a hole along the bore center  106 ) of a hole (such as the journal hole  102  or the communication hole  103 ). 
     Note that, the excess sprayed coating removal device  10  according to the embodiment is applicable to a cylinder block of a single cylinder engine, a V-type multi-cylinder engine with a bank angle of 180°, or a horizontally-opposed type multi-cylinder engine other than the cylinder block  100  of the in-line multi-cylinder engine. 
     Furthermore, the excess sprayed coating removal device  10  according to the embodiment includes the turret  11 . Hence, the excess sprayed coating removal device  10  can mount a direct jet nozzle that downwardly injects the cleaning solution in the axis direction, an L-shaped nozzle that includes a nozzle hole to inject the cleaning solution from the shaft portion extending in the axis direction and the leading end portion of the shaft portion vertically to the axis, and similar nozzle on the turret  11  by each turret surface other than the lance nozzle  30 . The excess sprayed coating removal device  10  of the turret type can properly use these nozzles to remove the excess sprayed coating adhering on the cylinder block  100 . 
     While, in the above description, the cylinder block  100  is described with an inverted state, it is needless to say that the cylinder block can be disposed in other directions. Further, while the excess sprayed coating removal device  10  is described with the turret type cleaning device, a cleaning device without a turret is also applicable. 
     (Second Embodiment) 
     A second embodiment will be described referring to  FIG. 4  to  FIG. 7 .  FIG. 4  is a vertical cross-sectional view of a lance nozzle  30  of an excess sprayed coating removal device  40  according to the second embodiment taken along a cross-sectional surface passing through a rotational axis  22 , in a state where the lance nozzle  30  is inserted into an inverted cylinder block  200 . Further,  FIG. 5  is a cross-sectional view taken along a line V-V in  FIG. 4 ,  FIG. 6  is a cross-sectional view taken along a line VI-VI in  FIG. 4 , and  FIG. 7  is a schematic diagram illustrating a method for using the excess sprayed coating removal device  40  according to the second embodiment. 
     The excess sprayed coating removal device  40  according to the second embodiment is applied to the cylinder block  200  of a V-type multi-cylinder engine. A crank chamber  207  of the cylinder block  200  is partitioned by the partition walls  101  into spaces (small chambers)  208  which each accommodate cylinder bores  203  and  204  two by two provided in two banks  201  and  202 , respectively, offset in phase. The cylinder bores  203  and  204  are provided so as to be offset longitudinally with respect to each other. 
     The excess sprayed coating removal device  40  includes a shield  41 . The shield  41  is removably secured to a turret  11 , and integrally moves with the turret  11 . Then, when the lance nozzle  30  moves in an axial direction, the shield  41  moves in accordance with the move of the lance nozzle  30 . The excess sprayed coating removal device  40  further includes a tilting device (unillustrated) that tilts the cylinder block  200 . The other configurations are similar to the first embodiment. Like reference numerals designate corresponding or identical elements to those of the first embodiment, and therefore such elements will not be further elaborated here. 
     The tilting device tilts the cylinder block  200  so that the cylinder bore  203  of one  201  of the banks faces downward in the vertical direction or the cylinder bore  204  of the other bank  202  faces downward in the vertical direction. A well-known tilting device (for example, a rotary table) can be used as the tilting device. 
     Referring to  FIG. 4  and  FIG. 5 , nozzle holes  35  and  36  are disposed with a positional relationship where, when the lance nozzle  30  is inserted into the crank chamber  207  along a bore center  106 , the excess sprayed coating adhering on an inner surface of a communication hole  103  can be removed, and disposed such that jets J 1  and J 2  are cutoff by the shield  41  not to enter into the cylinder bore  204  of the bank  202 . 
     The shield  41  is composed of: a shield plate  41   a  that receives the jets J 1  and J 2  from the nozzle holes  35  and  36  of the lance nozzle  30 ; and reinforcing plates  41   b  and  41   c  that reinforce the shield plate  41   a . The shield plate  41   a  is a plate bent into an inverted L shape when seen in the longitudinal direction (direction perpendicular to the drawing sheet of  FIG. 4 ) of the cylinder block  200 . The shield plate  41   a  has a shape (see  FIG. 5 ) with a short side W 1  one-third or more the diameter of the cylinder bore  204  (the other cylinder bore) but less than the diameter of the cylinder bore  204  and a long side X 1  exceeding the length of the lance nozzle  30 , and is disposed at a position offset in the horizontal direction in  FIG. 4  from the lance nozzle  30  by a distance almost equal to the radius of the cylinder bore  203 . 
     The length of the short side W 1  is configured such that, when the lance nozzle  30  is inserted along the bore center  106 , the end portion of the shield plate  41   a  on the side where the cylinder bore  204  is not disposed in the front-back direction of the engine (downward direction in  FIG. 6 ) reaches at least a tangent  48   b  of the bore center  106  and the cylinder bore  204  (see  FIG. 6 ). 
     With this configuration, when the lance nozzle  30  is inserted into the bore center  106 , the shield plate  41   a  is located directly above the boundary K between the banks  201  and  202  (boundary between the one cylinder bore  203  and the other cylinder bore  204 ). Furthermore, the long side X 1  of the shield plate  41   a  is set so that the shield plate  41   a  is prevented from making contact with the cylinder block  200  by leaving a slight gap therebetween when the lance nozzle  30  is inserted to the bottom end (state in  FIG. 4 ). Further, the leading end portion of the shield plate  41   a  is formed with a block portion  41   a   2  that shuts the jets J 1  and J 2 . It should be noted that the center of the shield plate  41   a  may be hollowed out in any portion except the block portion  41   a   2 . 
     The block portion  41   a   2  is formed integrally with the shield plate  41   a , and has a simple configuration. The block portion  41   a   2  erodes due to jets impinging thereon. The block portion  41   a   2  may be formed in a tabular shape or may have a central portion raised toward the direction of the lance nozzle  30  in plan view. Furthermore, the surface of the block portion  41   a   2  may be configured so as to be inclined in such a manner that the distance from the lance nozzle  30  decreases towards the leading end side. The block portion  41   a   2  may be fixed to the shield plate  41   a , for example by a bolt. In this case, the shield plate  41   a  serves as a supporting member of the block portion  41   a   2 . In this case, it is unnecessary to provide the reinforcing plates  41   b  and  41   c . The block portion  41   a   2  also may be configured so as to have a thickness more than the shield plate  41   a . The block portion  41   a   2  may be configured from a laminated material composed of a plurality of layers. 
     The reinforcing plate  41   b  supports, from inside, a bent portion located at an upper portion of the shield plate  41   a . The reinforcing plate  41   c  is provided outside the shield plate  41   a  so as to be elongated in a direction parallel to the lance nozzle  30 . The reinforcing plates  41   b  and  41   c  are provided at the width center of the shield plate  41   a  (see  FIG. 6 ), and prevent the shield plate  41   a  from being deformed under the dynamic pressure of the jets J 1  and J 2 . 
     Referring to  FIGS. 4 and 6 , a bent side portion  41   a   1  bent in the direction of the lance nozzle  30  is provided at one end in the longitudinal direction of the shield plate  41   a  on the side on which the cylinder bore  204  of the bank  202  is provided. When the lance nozzle  30  is positioned with respect to the bore center  106  of the cylinder bore  203 , the bent side portion  41   a   1  has, in plan view, at least a height such that it reaches a tangent  48   a  to the cylinder bore  204  passing through the bore center  106  of the cylinder bore  203 . At this time, preferably, the bent side portion  41   a   1  is provided as close to the partition wall  101  as possible. The bent side portion  41   a   1  prevents the jets J 1  and J 2  (especially jet j 2 ) from impinging on the sprayed coating  105  provided on the inner surface of the cylinder bore  204 . The leading end portion of the bent side portion  41   a   1  constitutes part of the block portion  41   a   2 . It should be noted that the bent side portion  41   a   1  are unnecessary depending on the conditions, such as the required pressure of the jets J 1  and J 2 . 
     Next, the method for use of the excess sprayed coating removal device  40  configured in this manner and the advantageous effects thereof will be described. The tilting device tilts the cylinder block  200  so that the cylinder bore  203  faces downward. Then the lance nozzle  30  rotating while jetting cleaning nozzle is inserted into the space  208  to remove the excess sprayed coatings adhering to the inner surface of the space  208  while moving the lance nozzle  30  downward along the bore centers  106  of all cylinder bores  203  associated with the bank  201 . 
     The jet J 2  inclines toward an oblique leading end direction. Then, the jet J 2  collides with the partition wall  101  and a skirt  109  on the part indicated by a bold two-dot chain line  45  in  FIG. 6 . Then, during lowering the lance nozzle  30  with rotating, the excess sprayed coating adhering on the top surface of the crank chamber  107  is also removed gradually from the peripheral portion. In this case, the shield  41  positions so as to face an opening of the cylinder bore  204  that communicates with the space  208 , and the block portion  41   a   2 , which is disposed on the leading end portion of the shield plate  41   a , intercepts the jets J 1  and J 2 . This prevents the jets J 1  and J 2  from colliding with the inner surface of the cylinder bore  204 . 
     When the lance nozzle  30  is lowered to the lowermost, an annular space SP where the excess sprayed coating cannot be removed is left around the cylinder bore  203 . The lance nozzle  30  returns to rise and removes the excess sprayed coating again with the jets J 1  and J 2 . In this process, the area where the excess sprayed coating can be removed is an area of a cross hatching  46 . At this time, the excess sprayed coatings adhering on the upper-side inner surface  103   a  and the lower-side inner surface  103   b  of the communication hole  103 , and on inner surfaces  102   a  and  102   b  of a journal hole  102  are also removed. Then, the excess sprayed coating of one half side of the space  208  of the crank chamber  207  can be removed. 
     Here, the shield plate  41   a  lowers with the lance nozzle  30  to the extent that the shield plate  41   a  does not contact with the cylinder block  200 . Accordingly, the shield plate  41   a  receives the jets J 1  and J 2  near the leading end portion to expand the wall surface of the crank chamber  207  with which the jets J 1  and J 2  can contact. That is, the nearer to the leading end the position where the shield plate  41   a  receives the jets J 1  and J 2  is disposed, the more the removal range of the excess sprayed coating can be expanded. 
     Subsequently, the excess sprayed coating of the other half of the space  208  of the crank chamber  207  is removed. The tilting device tilts the cylinder block  200  such that the cylinder bore  204  faces downward. In this case, the mounting position of the shield  41  to the turret  11  is moved by 180° in the rotation direction of the lance nozzle  30 . Alternatively, another turret surface of the turret  11  (unillustrated) that is configured such that the shield  41  is rotated by 180° in  FIG. 6  is preliminarily prepared. Then, the following configuration may be employed: when the excess sprayed coating is removed in a state where the cylinder bore  203  faces downward, a turret surface  11   a  with the configuration in  FIG. 6  (see  FIG. 4 ) is determined to use, and when the excess sprayed coating is removed in a state where the cylinder bore  204  faces downward, the other turret surface where the shield  41  is mounted on the opposite position to the configuration in  FIG. 6  is determined to use. Note that, the other turret surface is such as a surface on the opposite side to the turret surface  11   a  of the turret  11 . 
       FIG. 7  illustrates a state where the cylinder block  200  is tilted from a state in  FIG. 6  such that the cylinder bore  204  faces downward. In the removal step of the excess sprayed coating in  FIG. 6 , the shield  41  is inserted so as to face the opening of the cylinder bore  204 . Then, the excess sprayed coating in the region of a cross hatching  47  illustrated in  FIG. 7  is not removed. To remove the excess sprayed coating in the region of the cross hatching  47 , it is necessary to incline the cylinder block  200  such that the cylinder bore  204  faces downward. 
     Lowering the lance nozzle  30  with rotating in a state of  FIG. 7  processes the region of the cross hatching  47  and the part of a bold two-dot chain line  49  in the wall surface of the space  208 . Therefore, the excess sprayed coating removal device  40  can remove the excess sprayed coating of most regions except the peripheral area of the cylinder bores  203  and  204  in the crank chamber  207  of the cylinder block  200 . In this case, the shield  41  of which the mounting position is rotated by 180° from the mounting position in  FIG. 6  intercepts the jets J 1  and J 2  to prevent the sprayed coating  105  on the inner surface of the cylinder bore  203  from peeling. This ensures the excess sprayed coating removal device  40  to surely remove the excess sprayed coating inside the crank chamber  207  without peeling the sprayed coating  105  formed on the cylinder bore even with respect to the V-type multi-cylinder engine. 
     It should be noted that in the above description, the case where the mounting position of the shield  41  is changed between the banks  201  and  202 , or the case where the turret surface  11   a  for the bank  201  and a turret surface for the bank  202  (not shown) are preliminarily prepared to determine the turret  11 . However, alternatively, a turning device for turning the cylinder block  200  through 180° in plan view may be provided. In this case, the position of the cylinder bore  204  with respect to the cylinder bore  203  before turning, and the position of the cylinder bore  203  with respect to the cylinder bore  204  when the cylinder block  200  is turned 180° and tilted are the same. Thus, the combination of the nozzle  30  and the shield  41  is applicable to the bank  201  and the bank  202  in common. Furthermore, two excess sprayed coating removal devices  40  may be provided so that one of the excess sprayed coating removal devices  40  processes one bank (for example, the right bank) and the other excess sprayed coating removal device  40  processes the other bank (for example, the left bank). In addition, the arrangement may be such that the single turret  11  is mounted with a pair of shields  41  arranged with a pitch of 180°. 
     (Third Embodiment) 
     A third embodiment will be described with reference to  FIG. 8 .  FIG. 8  is a longitudinal sectional view of an excess sprayed coating removal device  50  according to the third embodiment taken along the rotational axis  22  of a lance nozzle  60 , with the lance nozzle  60  inserted in the inverted cylinder block  100 . 
     The lance nozzle  60  of the third embodiment differs from the excess sprayed coating removal device  10  of the first embodiment in that an automatic-tool-changing cleaning machine is used. The automatic-tool-changing cleaning machine has a general structure similar to a machining center. However, while the machining center is used for cutting, the automatic-tool-changing cleaning machine is used for cleaning or deburring using jets. Furthermore, the high-pressure cleaning liquid in the range of 10 to 80 MPa is supplied to the main spindle. Therefore, although the machining center and the automatic-tool-changing cleaning machine differ from each other mainly in accuracy, mechanical stiffness, and mildew resistance, the major structures thereof are the same. Under such circumstances, differences from the first embodiment will be described in detail in the following description, in which like reference signs denote like portions and the description thereof is omitted. 
     In the excess sprayed coating removal device  50 , a main spindle  51  with a shank hole  51   a  is rotatably supported by a bearing  53  in a main spindle head  52  as a spindle casing which is provided to an orthogonal three-axis moving device. The main spindle head  52  is provided with a detent hole  56  adjacent to the shank hole  51   a . The main spindle head  52  is provided with a flow path  55  opening into the detent hole  56 . The detent hole  56  is provided with packing (not shown) for sealing the detent hole  56  with respect to an insertion portion  62 . 
     The lance nozzle  60  is replaced by means of an automatic tool changing device not shown. The lance nozzle  60  is equipped with: a body  61 ; a rotor  65  that journaled to the body  61 ; and flow paths  67  and  68  that supplies cleaning liquid to the interior of the rotor  65  from the detent hole  56 . 
     The body  61  has a general cylindrical shape, and the abdomen of the body  61  is equipped with a protruding portion  61   a . The protruding portion  61   a  is equipped with the insertion portion  62  that is inserted into the detent hole  56 . When the lance nozzle  60  is installed in the main spindle  51 , the insertion portion  62  is fitted and inserted into the detent hole  56 . A cylindrical hole  64 , which is a stepped through-hole, is provided in the center of the body  61 . Bearings  63  are provided at either end of the cylindrical hole  64 . 
     The rotor  65  includes a taper shank  65   a , a flange  65   b , a cylindrical portion  65   c , and a shaft body  65   d  integrally manufactured. The taper shank  65   a  is equipped with a conic surface in close contact with the shank hole  51   a . When the taper shank  65   a  and the shank hole  51   a  are brought into close contact with each other, the lance nozzle  60  is installed in the main spindle  51 . At this time, since the insertion portion  62  is inserted into the detent hole  56 , the body  61  does not rotate. The flange  65   b  is formed in a disk-like shape. The cylindrical portion  65   c  is equipped with a cylindrical surface  65   c   1  for sliding against the cylindrical hole  64 . The cylindrical surface  65   c   1  is provided with a circumferential groove  65   c   2 . Both ends of the cylindrical portion  65   c  are supported by the bearings  63 . The shaft body  65   d  corresponds to the shaft body  33  of the lance nozzle  30  in the first embodiment, and therefore the detailed description thereof is omitted. 
     The flow path  67  is provided between the insertion portion  62  of the body  61  and the cylindrical hole  64 . The flow path  67  opens into the circumferential groove  65   c   2  of the rotor  65 . The flow path  68  is provided inside the rotor  65 . The flow path  68  is of T-shape, which is composed of: a through-hole that has both ends opening into the circumferential groove  65   c   2 ; and a vertical hole that is provided along the center axis of the shaft body  65   d . The flow path  67  and the flow path  68  communicate with each other through the circumferential groove  65   c   2 . The circumferential groove  65   c   2  circumferentially evenly distributes the cleaning liquid supplied from the flow path  67 , and continuously supplies cleaning liquid to the nozzle holes  35 ,  36  even if the rotational direction of the rotor  65  is changed. The nozzle holes  35 ,  36  communicates with the flow path  68 . Furthermore, when the lance nozzle  60  is installed in the main spindle  51 , the flow path  67  communicates with the flow path  55 . The cleaning liquid supplied from the cleaning liquid supplying device  17  passes through the flow paths  55 ,  67 , and  68  and is discharged as the jets J 1  and J 2  from the nozzle holes  35 ,  36 . The third embodiment can also provide the operational advantage similar to the first embodiment. 
     The present invention is not to be understood limiting to the above-described three embodiments. The deformation and the combination of the above-described three embodiments may be performed to use. For example, the lance nozzle  60  of the third embodiment can be combined with the shield  41  of the second embodiment. Also, the main spindle head  52  of the excess sprayed coating removal device  50  of the third embodiment may be combined with the shield  41  of the second embodiment. Alternatively, the shield  41  of the second embodiment can be mounted on the end surface of the body  61  of the third embodiment. Furthermore, the shield  41  of the second embodiment may be combined with a linear guide and a moving device such as a cylinder to configure a shield into which the shield  41  can be inserted. 
     Note that, while in the above-described embodiments, the orthogonal three-axis type moving device is used for the move of the turret  11 , instead of the moving device, a vertical articulated robot and a parallel link robot may be employed. Further, it is needless to say that the lance nozzle according to the present invention can be widely applied to the removal of adhered substances adhered on the inner surfaces of various structures other than the removal of the excess sprayed coating inside the cylinder block.