Abstract:
A section of an engine mount bracket and a section of an engine accessory pass through a timing belt cover from the inside to the outside of the engine. The timing belt cover has an engine accessory opening and an engine mount bracket opening. During engine assembly, the engine accessory opening and engine mount bracket opening are aligned with the engine mount bracket and engine accessory, providing accurate alignment of the timing belt cover onto the engine. The alignment process prevents damage of the timing belt cover bolts as well as the threaded timing belt cover bolt insertion openings, resulting in an efficient process for engine assembly.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an engine cover structure. More specifically, the present invention relates to an engine mount and structure used to attach a timing belt cover. 
     In a conventional engine mount and timing belt cover, the timing belt cover includes an inside cover and an outside cover. The timing belt is enclosed by the cover when the inside and outside covers are joined. The inside cover is secured to the engine with bolts that fit into threaded openings in the engine block. The outside cover must then be visually aligned in relation to a plurality of openings around the perimeter of the inside cover. If the outside cover is not correctly aligned, the belt cover clamping bolts will not seat properly. An improper alignment leads to misalignment problems including damaging or stripping the threaded opening designed to receive the belt cover clamping bolts. In order to prevent this kind of damage, the outside cover must often be realigned, making assembly more time consuming, thereby decreasing efficiency. 
     If a separate part is provided to allow the timing belt cover to be aligned, the number of parts is increased, the structure becomes more complex, and costs are increased. 
     Referring to FIGS. 20 through 22, a conventional engine mount and timing belt cover  202  includes a cylinder block  204  with a cylinder head  206  mounted thereon. A crank shaft  208  is on cylinder block  204 . A crank timing pulley  210  is fixed to crank shaft  208  using a crank pulley attachment bolt  212 . A cam shaft  214  is disposed on cylinder head  206 . A cam timing pulley  216  is fixed to cam shaft  214  using a cam pulley attachment bolt  218 . A timing belt  220 , wrapped around crank pulley  210  and cam pulley  216 , is driven by crank shaft  208 . 
     Other engine components can be operated by timing belt  220 . A water pump  222  is an engine component that is operated by timing belt  220 . A water pump housing  224  attaches to cylinder block  204  with a plurality of water pump clamping bolts  226 . A belt tensioner  228  attaches to cylinder block  204  with a tensioner attachment bolt  230 . An oil pump  232  is another engine component operated by timing belt  220 . 
     A timing belt inside cover  234  attaches to cylinder head  206 , water pump  222 , oil pump  232 , cylinder block  204 , and cylinder head  206  using a plurality of inside cover clamping bolts (not shown in the figures). 
     A timing belt outside cover  238  attaches to timing belt inside cover  234 , water pump  222 , and oil pump  232  using a plurality of belt cover clamping bolts  240  disposed along the perimeter of timing belt cover  238 . Timing belt cover  238  forms a belt chamber  236  for timing belt  220 . 
     When timing belt cover  238  is attached, a plurality of belt cover bolt insertion openings (not shown in the figures), formed on timing belt cover  238 , are aligned with a plurality of belt cover bolt openings  242  formed on timing belt inside cover  234 . Belt cover clamping bolts  240  are then screwed in to attach timing belt cover  238 . 
     This type of timing belt cover structure has been presented in Japanese laid-open utility model publication number 6-25652, Japanese utility model number 2545119, Japanese laid-open utility model publication number 5-79195, Japanese laid-open utility model publication number 63-146256, Japanese laid-open utility model publication number 63-9444, Japanese laid-open patent publication number 7-259578, Japanese laid-open patent publication number 6-193460, Japanese laid-open patent publication number 5-203019, Japanese laid-open utility model publication number 5-89845, and Japanese laid-open utility model publication number 3-43563. 
     In the conventional technology disclosed in Japanese examined utility model publication number 6-25652, a pump case of a water pump and an engine mount bracket are disposed adjacent to each other. A ring-shaped rib is disposed on the outer surface of the water pump case to provide improved sealing. 
     Japanese utility model publication number 2545119 discloses a timing belt cover divided into a plurality of sections. 
     Japanese laid-open utility model publication number 5-79195 discloses a timing belt cover attached to a pump case with an elastic member interposed therebetween. 
     Japanese laid-open utility model publication number 63-146256 discloses a timing belt cover divided into sections, and an engine mount bracket disposed on the timing belt cover. 
     Japanese laid-open utility model publication number 63-9444 discloses an engine mounting bracket seat on an end cover. 
     Japanese laid-open patent publication number 7-259578 discloses an engine mount attachment seat on a timing belt cover. 
     Japanese laid-open patent publication number 6-193460 discloses a side of a chain cover toward an engine cylinder block attached to the lower portion of an engine mount bracket. 
     Japanese laid-open patent publication number 5-203019 discloses an engine mount bracket disposed on a front cover. 
     Japanese laid-open utility model publication number 5-89845 discloses a longitudinal section of a timing belt cover formed as a high-strength section. An attachment section for the main engine unit is disposed on this high-strength section. 
     Japanese laid-open utility model publication number 3-43563 discloses an engine mounting structure having radial ribs to connect thick sections of a cam journal, boss, and the like. 
     OBJECT AND SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an engine mount and cover structure which overcomes the foregoing problems. 
     It is a further object of the present invention to provide an engine mount and cover structure having components which allow for efficient assembly. 
     It is another object of the present invention to provide an engine structure allowing accurate alignment of a timing belt cover onto an engine. 
     The present invention provides an engine cover structure in which an engine accessory is fixed to a cylinder block of an engine. A crank shaft is disposed on the cylinder block. A crank timing pulley is fixed to the crank shaft. A cam shaft is disposed on a cylinder head of the engine. A timing pulley is fixed to the cam shaft. A timing belt extends between the crank timing pulley and the cam timing pulley. A timing belt cover is fixed to the engine using belt cover clamping bolts so that the timing belt cover surrounds the timing belt. In this engine cover structure, an engine mount bracket is fixed to the cylinder block. A section of the engine mount bracket and a section of the engine accessory are passed through the timing belt cover from the inside to the outside. 
     Briefly stated, the present invention provides a section of an engine mount bracket and a section of an engine accessory passing through a timing belt cover from the inside to the outside of the engine. The timing belt cover has an engine accessory opening and an engine mount bracket opening. During engine assembly, the engine accessory opening and engine mount bracket opening are aligned with the engine mount bracket and engine accessory, providing accurate alignment of the timing belt cover onto the engine. The alignment process prevents damage of the timing belt cover bolts as well as the threaded timing belt cover bolt insertion openings, resulting in an efficient process for engine assembly. 
     According to an embodiment of the present invention, there is provided a structure for an engine comprising an engine mount bracket attached to the engine; an engine accessory attached to the engine; a timing belt cover attached to the engine; the timing belt cover having at least a accessory insertion opening and a bracket insertion opening; and a section of the engine mount bracket passing through the bracket insertion opening and a section of the engine accessory passing through the accessory insertion opening, thereby accurately aligning the timing belt cover on the engine. 
     According to another embodiment of the present invention, there is provided an engine structure comprising an engine accessory attached to a cylinder block of the engine; a crank timing pulley on a crank shaft of the engine; a cam shaft on a cylinder head of the engine; a timing pulley on the cam shaft; a timing belt extending between the crank timing pulley and the cam timing pulley; a timing belt cover fixed to the engine; an engine mount bracket on the cylinder block; and a section of the engine mount bracket and a section of the engine accessory passing through the timing belt cover, thereby accurately aligning the timing belt cover with the engine. 
     The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front-view drawing of an engine. 
     FIG. 2 is a partially cut-away cross-sectional drawing of the engine of FIG.  1 . 
     FIG. 3 is a cross-section drawing of the engine of FIG.  1 . 
     FIG. 4 is a schematic close-up drawing of FIG.  3 . 
     FIG. 5 is a side-view drawing of the attachment section of the engine mount bracket. 
     FIG. 6 is a side-view drawing as seen from arrow IV from FIG.  5 . 
     FIG. 7 is a front-view drawing of the cylinder block. 
     FIG. 8 is a schematic side-view drawing of FIG.  7 . 
     FIG. 9 is a front-view drawing of the water pump case. 
     FIG. 10 is a front-view drawing of the engine mount bracket. 
     FIG. 11 is a front-view drawing showing the timing belt inside cover in an attached state. 
     FIG. 12 is a side-view drawing of FIG.  11 . 
     FIG. 13 is a front-view drawing of the water pump case according to a second embodiment. 
     FIG. 14 is a front-view drawing of the engine mount bracket according to the second embodiment. 
     FIG. 15 is a front-view drawing showing the engine mount bracket attached to the water pump case according to the second embodiment. 
     FIG. 16 is a side-view drawing showing the engine mount bracket, according to a third embodiment, in an attached state. 
     FIG. 17 is a side-view drawing of FIG.  16 . 
     FIG. 18 is a drawing showing the positioning of the engine mount bracket and the water pump case according to a fourth embodiment. 
     FIG. 19 is a side-view drawing of the guide body according to a fifth embodiment. 
     FIG. 20 is a front-view drawing of a conventional engine. 
     FIG. 21 is a cross-section drawing of a conventional engine. 
     FIG. 22 is a front-view drawing of a conventional engine with the timing belt cover removed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1 through 4, an engine  2 , mounted in an automobile (not shown in the figures), includes a cylinder block  4 , a cylinder head  6 , and a cylinder head cover  8 . 
     A crank shaft  10  is supported in cylinder block  4 . A trochoidal oil pump  12 , driven by the end surface of crank shaft  10 , is an engine accessory. Oil pump  12  has an oil pump case  14  and an integrally formed pump plate  16 . A knock pin (not shown in the figures) and an oil pump clamping bolt (not shown in the figures) provide accurate positioning of oil pump case  14  to stud bolt threaded openings  4   a  on the end surface of cylinder block  4 . 
     A crank timing pulley  18  and a crank pulley  20  are attached to an end of crank shaft  10  with a crank pulley attachment bolt  22 . A cam shaft  24  is supported in cylinder head  6 . A cam timing pulley  26  attaches to cam shaft  24  with a cam pulley attachment bolt  28 . A timing belt  30  extends across crank timing pulley  18  and cam timing pulley  26 . 
     A water pump  32  is on cylinder block  4  as an engine accessory. Water pump  32  includes a water pump case  34  and a water pump shaft  36 . 
     Referring to FIGS. 3 and 4 and FIGS. 7 through 9, one end of water pump case  34  is positioned with stud bolts  38  fixed in stud bolt threaded openings  4   a  on one end surface of cylinder block  4 . Stud bolts  38  and another water pump attachment bolt  40  serve to attach water pump case  34  to the end surface of cylinder block  4 . End sections  38   a  of stud bolts  38  engage with nuts  42 . A diameter D 1  of a stud bolt insertion opening  44 , through which stud bolts  38  of water pump case  34  are inserted, matches the maximum diameter of stud bolts  38 . Diameter D 1  is slightly smaller than a diameter D 2  of a water pump bolt insertion opening  46 , through which a water pump clamping bolt  40  is inserted. These relative diameters allows for the attachment of water pump case  34  to cylinder block  4  with accurate alignment. A belt tensioner attachment seat  48  is on water pump case  34 . A belt tensioner  50  attaches to belt tensioner attachment seat  48  to adjust the tension of timing belt  30 . Belt tensioner  50  rotates around a rotation shaft  54  disposed in a shaft opening  52  formed on belt tensioner attachment seat  48 . 
     A water pump shaft  36  extends in the same direction as crank shaft  10 . A pump impeller  56  is disposed on the end of water pump shaft  36  having a smaller diameter. Pump impeller  56  circulates cooling water inside a water jacket  58  of cylinder block  4 . One end of water pump shaft  36  is supported at one end of water pump case  34  by a shaft sealing member  60 . The end of water pump shaft  34  with the larger diameter is supported at the other end of water pump case  34 . An attachment flange  62  is fixed to a section of water pump shaft  34  projecting out from the end surface of water pump case  34 . A water pump pulley  64  attaches to attachment flange  62  using a pump-pulley attachment bolt  66 . Water pump pulley  64  and crank pulley  20  are attached after a timing belt cover  98 , described later, is attached to engine  2 . A drive belt  68  extends between water pump pulley  64  and crank pulley  20 . 
     Referring to FIG.  5  and FIG. 6, an engine mount bracket  70  attaches to an end surface of cylinder block  4 . Engine mount bracket  70  includes a fixing side  72 , located toward cylinder block  4 , and a mount attachment boss  74 , connected to fixing side  72 , extending parallel to water pump shaft  36 . Fixing side  72  is fixed using a bracket clamping bolt  78  inserted through a bracket bolt insertion opening  76  into a bracket bolt threaded opening  4   b  formed on the end surface of cylinder block  4 . To allow engine mount bracket  70  to be properly aligned, an alignment extension  80  is formed as a projection on fixed side  72  toward water pump case  34  and stud bolt  38 . Alignment extension  80  has an alignment opening  82  into which an end section  38   a  of stud bolt  38 , projecting from a nut  42  engaged with end section  38   a  of stud bolt  38 , is inserted. When attaching fixing side  72  of engine mount bracket  70  to cylinder block  4  using bracket clamping bolt  78 , alignment opening  82  is fitted to end section  38   a  of stud bolt  38 . This allows engine mount bracket  70  to be properly aligned and accurately positioned at a prescribed position. Even if nut  42  becomes loose, alignment extension  80  prevents nut  42  from dropping. Also, a mount attachment threaded opening  84  is formed on an end surface of mount attachment boss  74  of engine mount bracket  70 . 
     Referring to FIG. 10, in this embodiment of engine mount bracket  70 , a center  78   c  of bracket attachment bolt  78  is offset by a distance L 1  from a center  76   c  of bracket bolt insertion opening  76  of bracket attachment bolt  78 . A center  82   c  of alignment opening  82  is offset from a center  38   c  of stud bolt  38  by a distance L 2 . 
     Referring to FIG. 3, FIG. 11, and FIG. 12, a timing belt inside cover  86  attaches to an end surfaces of cylinder block  4  and cylinder head  6  using inside cover clamping bolts  88 . Inside cover clamping bolts  88  are inserted through a grommet  92  into an inside cover bolt insertion opening  90  of timing belt inside cover  86 . Inside cover clamping bolts  88  screw to cylinder head  6 . A plurality of belt cover bolt threaded openings  94  are along a perimeter of timing belt inside cover  86 . 
     A timing belt cover  98  attaches with belt cover clamping bolts  100  to timing belt inside cover  86 , water pump case  34 , and oil pump case  14  to form a belt chamber  96  along timing belt  30 . A plurality of cover bolt insertion openings (not shown in the figures) are along a perimeter of timing belt cover  98 . 
     Timing belt cover  98  has a pump-side insertion opening  102  and a bracket-side insertion opening  104 . An end of water pump case  34  passes through pump-side insertion opening  102 . Mount attachment boss  74 , which is a section of engine mount bracket  70 , passes through bracket-side insertion opening  104 . 
     Referring again to FIG. 4, the other end of water pump case  34  is supported on the side of timing belt cover  98  toward water pump case  34  with a pump-side sealing member  106 . Pump-side sealing member, which is an accessory-side sealing member, is supported with an E-ring  110  attached to an E-ring groove  108  of water pump case  34 . Pump-side sealing member seals pump-side insertion opening  102 . 
     Referring back to FIG. 5, in engine mount bracket  70 , mount attachment boss  74  is supported by a bracket-side sealing member  112 . 
     First Embodiment 
     Stud bolt  38  is inserted through stud bolt insertion opening  44 , having a diameter that corresponds to the maximum diameter of stud bolt  38 . Diameter D 1 , of stud bolt insertion opening  44 , is smaller than diameter D 1 , of water pump bolt insertion opening  46 . This attaches pump case  34  to cylinder block  4  and cylinder head  6 , while allowing water pump  32  to be accurately aligned to cylinder block  4 . 
     With engine mount bracket  70 , end section  38   a  of stud bolt  38  is fitted in bracket attachment bolt  78  and alignment opening  82 . Center  76   c , of bracket bolt insertion opening  76 , is offset from center  78   c , of bracket attachment bolt  78 , by a distance L 1 . Center  82   c , of positioning opening  82 , is offset from center  38   c , of stud bolt  38 , by a distance L 2 . This allows for the attachment of engine mount bracket  70  to cylinder block  4  with an accurate alignment. 
     With oil pump  12 , the knock pin and the oil pump clamping bolt (not shown in the figures) are used to accurately align oil pump  12  to the end surface of cylinder block  4 . 
     Thus, water pump  32 , engine mount bracket  70 , and oil pump  12  are attached to cylinder block  4  with accurate alignment relative to each other. 
     Timing belt cover  98  is guided into place by pump-side sealing member  106  on one side of water pump case  34  of water pump  32 . Timing belt cover  98  is also guided by bracket-side sealing member  112  of mount attachment boss  74  of engine mount bracket  70 . This allows timing belt cover  98  to be accurately aligned with water pump  32  and oil pump  12 . As a result, the cover bolt insertion openings of timing belt cover  98  are aligned with belt cover bolt threaded openings  94  on water pump  32  and oil pump  12 . This allows timing belt cover  98  to be attached quickly and easily while preventing belt cover bolt threaded openings  94  from being damaged. 
     Inside cover attachment bolt  88  attaches timing belt inside cover  86  to cylinder head  6  through grommet  92 . Thus, when timing belt cover  98  is being attached, belt cover bolt threaded opening  94  is easily aligned to the belt cover bolt opening on timing belt cover  98 , thereby avoiding attachment difficulties. 
     Since timing belt cover  98  is attached while being guided by a section of water pump case  32  and a section of engine mount bracket  70 , timing belt cover  98  is accurately aligned, and attachment is easily performed. Separate parts are unnecessary, making the structure simple and inexpensive. 
     Since pump-side sealing member  106  is on pump-side opening  102 , and bracket-side sealing member  112  is on bracket-side opening  104 , timing belt cover  98  attaches firmly with no looseness. Furthermore, timing belt cover  98  is accurately aligned. 
     With water pump case  34  of water pump  32 , stud bolt  38  is inserted through positioning opening  82 , having diameter D 2  that is smaller than diameter D 1  of water pump bolt insertion opening  44 . Thus, stud bolt  38  provides alignment without the need for separate parts. This allows water pump  32  to be aligned accurately and inexpensively. 
     Furthermore, center  76   c , of bracket bolt insertion opening  76 , and center  78   c , of bracket clamping bolt  78 , are offset by distance L 1 . Center  82   c , of alignment opening  82 , and center  38   c , of stud bolt  38 , are offset by distance L 2 . This allows engine mount bracket  70  to be positioned accurately without the use of separate parts, while only requiring a simple and inexpensive structure. 
     In engine mount bracket  70 , alignment is performed with end section  38   a  of stud bolt  38 . Thus, separate parts such as knock pins are not required, reducing the number of parts. Moreover, there is no need to form an opening on cylinder block  4 , thus further reducing costs. 
     Since alignment extension  80  of engine mount bracket  70  is positioned at end section  38   a  of stud bolt  38 , nut  42  cannot come off even if it becomes loose. This prevents nut  42  from damaging other parts. 
     Since engine mount bracket  70  is not fixed to separate elements, such as water pump  32 , the vibrations from the engine mount attached to mount attachment boss  74  does not affect the other elements, such as a water pump gasket (not shown in the figures). Thus, leakage and the like are prevented. 
     Second Embodiment 
     Referring to FIGS. 13 through 15, a second embodiment of the present invention is described. Elements that serve the same function as the embodiment described above are assigned the same numerals. 
     The characteristics of the second embodiment of the present invention are as follows. Pump-side processed surfaces  122 - 1  and  122 - 2  are formed on sections of water pump case  34 . Bracket-side processed surfaces  124 - 1  and  124 - 2 , corresponding to pump-side processed surfaces  122 - 1  and  122 - 2 , are on sections of engine mount bracket  70 . 
     According to this second embodiment, bracket-side processed surfaces  124 - 1  and  124 - 2  engage with pump-side processed surfaces  122 - 1  and  122 - 2  so that water pump  32  and engine mount bracket  70  are accurately positioned. 
     Third Embodiment 
     Referring to FIG.  16  and FIG. 17, a third embodiment of the present invention is described. The characteristics of the third embodiment are as follows. A positioning section  132  is on fixed-side section  74  of engine mount bracket  70 . Positioning section  132  extends near end section  38   a  of stud bolt  38 , covering nut  42 . Positioning section projects toward water pump case  34 . A positioning pin  134 , oriented toward the surface of water pump case  34 , is on positioning section  132 . On the surface of water pump case  34 , a positioning opening  136  faces positioning pin  134 . 
     According to the third embodiment, when engine mount bracket  70  is attached, positioning pin  134  is inserted into positioning opening  136 , thus allowing engine mount bracket  70  to be properly aligned. Since engine mount bracket  70  is then attached to cylinder block  4  using bracket clamping bolt  78 , engine mount bracket  70  is accurately positioned. 
     Even if nut  42  comes loose, positioning section  132  prevents nut  42  from dropping down. This prevents nut  42  from damaging other elements. 
     Fourth Embodiment 
     Referring to FIGS. 5 and 18, a fourth embodiment SG 1  of the present invention is described. The characteristics of fourth embodiment SG 1  are as follows. Mount attachment boss  74  of engine mount bracket  70  projects from water pump case  34  by a distance L 3 . A staircase shape is formed from the projections of water pump case  34  and engine mount bracket  70 . 
     According to this fourth embodiment, when timing belt cover  98  is attached, bracket-side opening  104  is fitted before pump-side opening  102 , thus providing easier assembly. 
     Fifth Embodiment 
     Referring to FIGS. 5 and 19, a fifth embodiment SG 2  of the present invention is described. The characteristics of fifth embodiment SG 2  are as follows. A tapered guide  142  is removably disposed on mount attachment boss  74  to fit with timing belt cover  98  when timing belt cover  98  is attached. Guide  142  includes a tapered guide section  144  and a compound section  148  mounted on mount attachment boss  74 . Guide  142  has a slit  146 . 
     According to the fifth embodiment, when timing belt cover  98  is attached, compound section  148  of guide body  142  mounts to mount attachment boss  74 . Then, bracket opening  104  of timing belt cover  98  fits to guide section  144 . This allows timing belt cover  98  to easily fit to mount attachment boss  74 . Once timing belt cover  98  is attached to mount attachment boss  74 , guide body  142  is pulled off of mount attachment boss  74 . This allows timing belt cover  98  to be easily attached. 
     With the present invention, it is also possible to accurately align water pump  32  and engine mount bracket  70  in other ways such as the following. Water pump  32  and engine mount bracket  70  can be formed integrally. Water pump  32  and engine mount bracket  70  can be positioned with a knock pin. Water pump  32  and engine mount bracket  70  and oil pump  12  can be also formed integrally. 
     As the detailed description of the present invention presented above shows, an engine mount bracket is fixed to a cylinder block, and a section of the engine mount bracket and a section of an engine accessory are passed through a timing belt cover from the inside to the outside. Thus, a section of the engine accessory and a section of the engine mount bracket serve to position the timing belt cover, allowing easy alignment of the timing belt cover. This allows assembly to take place more efficiently, eliminates the need for separate elements to perform alignment, provides a simplified structure, and reduces costs. 
     Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.