JP5462854B2 - Auxiliary machine mounting structure for internal combustion engine - Google Patents

Description

  The present invention relates to an auxiliary machine mounting structure for an internal combustion engine, and more particularly to a structure for mounting an auxiliary machine driven by a camshaft to a cylinder head.

  In a DOHC type internal combustion engine, a fuel pump such as an injection pump (fuel injection pump) that supplies high pressure fuel to an injector or a supply pump that supplies high pressure fuel to a common rail of a diesel engine is driven by a camshaft. (For example, Patent Documents 1 and 2). In the internal combustion engine according to Patent Documents 1 and 2, an extension portion that protrudes outside the edge wall of the cylinder head is provided at one end of the camshaft. The extension portion is cantilevered by a bearing provided on the edge wall of the cylinder head, and has a pump drive cam for driving the fuel pump at the protruding end. The fuel pump includes a plunger driven by a pump drive cam, and a housing that supports a pump body including the plunger is bolted to a side surface of an edge wall of the cylinder head. In the internal combustion engine according to Patent Document 2, the housing that supports the fuel pump is bolted to the bearing in addition to the edge wall of the cylinder head.

JP 2003-184688 A Japanese Patent Laid-Open No. 11-324846

  Since the fuel pump has a large driving resistance (advancing and retracting resistance of the plunger), the load received from the camshaft is large. Further, since the fuel pump is heavy even in the auxiliary machine, a relatively large load is applied to the connecting portion with the cylinder head. Therefore, as in the internal combustion engines according to Patent Documents 1 and 2, a bearing that supports the extension of the camshaft is provided on the edge wall of the cylinder head, and the housing that supports the fuel pump is a separate member from the bearing. When fastened to the edge wall, there is a problem that a mouth opening occurs between the cylinder head and the fuel pump housing due to a load applied to the fuel pump from the camshaft. When the opening of the mouth occurs and the relative position between the bearing and the housing of the fuel pump changes, uneven wear occurs in the journal portion of the extension portion supported by the bearing and the bearing, and vibration and noise occur. Further, as in Patent Document 2, when the housing of the fuel pump is directly fastened to the bearing, the load of the fuel pump is directly applied to the bearing, and the above-described uneven wear, vibration, and abnormal noise are noticeable. .

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the stability of coupling between an auxiliary machine driven by a camshaft and a cylinder head in an internal combustion engine.

  In order to solve the above-mentioned problems, the present invention provides an auxiliary machine mounting structure for an internal combustion engine (1), a cylinder head (2) having a valve operating chamber (16) on one side, and rotating in the valve operating chamber. A camshaft (37) that is arranged freely and has an extension (51) coaxially and integrally at its end, and is arranged between the cylinder head and the extension, and is arranged on the valve chamber side of the cylinder head. A first housing (42) coupled to the end surface (17) and projecting outward beyond the end (13) of the cylinder head on the side where the extension is disposed in the extending direction of the camshaft. ), A second housing (43) coupled to the first housing and defining a housing chamber (48) for receiving the extension between the first housing, and a plunger ( 86) Further, an auxiliary machine (4) supported by the second housing and driven by the advancement and retraction of the plunger, an auxiliary machine drive cam (61) formed in the extension part to advance and retract the plunger, and the first housing And a first bearing (53, 54) that rotatably supports the extension portion.

  According to this configuration, since the first housing receives a load in one direction of the camshaft radial direction from the accessory drive cam, the load received from the accessory drive cam can be reduced by coupling to the cylinder head from the valve operating chamber side. It can resist efficiently. That is, the coupling stability between the first housing and the cylinder head is improved, and the possibility that a mouth opening occurs between the first housing and the cylinder head is reduced. Further, since the first bearing for supporting the camshaft is formed integrally with the first housing, the first housing receives a load from the accessory drive cam from the accessory drive cam via the accessory and the second housing. A reaction force is received from the auxiliary machine via the drive cam, camshaft, and first bearing. Due to this reaction force, the first housing is pressed to the cylinder head side, so that the coupling between the first housing and the cylinder head becomes stronger, and an opening occurs in the coupling surface between the first housing and the cylinder head. The fear is reduced.

  Another aspect of the present invention is provided integrally with the first housing to rotatably support a portion between the portion of the extension supported by the first bearing and the auxiliary drive cam. A second bearing (56, 57) is further provided.

  According to this configuration, the extension portion is stably supported by the first housing via the first bearing and the second bearing.

  In another aspect of the present invention, the second bearing is disposed inward of the cylinder head in the extending direction of the camshaft and more inward of the cylinder head than the end of the cylinder head. In the extending direction of the camshaft, the camshaft is disposed outward of the cylinder head from the end of the cylinder head.

  According to this configuration, since the first bearing and the second bearing are arranged in a portion of the first housing that overlaps the cylinder head in the camshaft extending direction, the first bearing and the second bearing serve as the cylinder block. It is supported and the support rigidity of the extension portion is improved. Further, by arranging the auxiliary machine drive cam outside the end of the cylinder head, the space for arranging the auxiliary machine drive cam in the cylinder head can be omitted, so that the size of the cylinder head can be reduced.

  Another aspect of the present invention is characterized in that a portion of the extension portion provided with the accessory drive cam is cantilevered by the second bearing.

  According to this configuration, by supporting the extension portion in a cantilever manner, the bearing that supports the end portion of the extension portion can be omitted, and the extension portion can be shortened. Thereby, the size of the first housing and the internal combustion engine as a whole in the cam shaft direction can be reduced.

  According to another aspect of the present invention, a portion of the extension portion between the portion supported by the first bearing and the portion supported by the second bearing has an impact facing the extending direction of the camshaft. A thrust plate (62) having a temporary surface is protruded, and a thrust plate receiving groove (64) for receiving the thrust plate rotatably in the rotation direction of the camshaft is formed in the first housing. It is characterized by.

  According to this configuration, since the thrust plate is disposed in the dead space between the first bearing and the second bearing, the extension portion and the first housing can be reduced in size.

  Another aspect of the present invention includes an oil groove (121) for guiding lubricating oil overflowing from at least one of the first bearing and the second bearing to the thrust plate receiving groove.

  According to this configuration, the lubricating oil can be supplied to the thrust plate receiving groove from at least one of the first bearing and the second bearing.

  In another aspect of the present invention, the thrust plate has a protrusion (63) protruding in a radial direction, and the second housing is provided with a sensor for detecting the protrusion.

  According to this configuration, the thrust plate can be used in combination as a pulsar plate for angle detection, and the number of parts can be reduced. Further, the thrust plate generally has high rigidity and is difficult to be deformed, so that the detection error can be reduced.

In another aspect of the present invention, the camshaft rotatably disposed in the valve operating chamber and having the extension (51) coaxially and integrally at an end thereof is an exhaust side camshaft (37), the valve chamber, before Symbol exhaust camshaft parallel-arranged intake camshaft (30) rotatably supported, said first housing, rotating the end of the intake camshaft The intake side bearings (68, 69) are supported in a possible manner.

  According to this configuration, since the first housing supports the intake side camshaft, a part of the bearing provided in the cylinder head to support the intake side camshaft can be omitted. Thereby, the space which arrange | positions a 1st housing in a valve operating chamber can be ensured, and the support surface with respect to the cylinder head of a 1st housing can be increased.

In another aspect of the present invention, the valve operating chamber is surrounded by edge walls (11 to 14) extending along the side edge of the cylinder head, and the end surface of the cylinder head on the valve operating chamber side. Is formed by a protruding end of the edge wall, and a rocker shaft (33) extending in parallel with the camshaft is disposed in the valve chamber, and the first housing is coupled to the end surface (17). And an extension portion (66) extending into the valve operating chamber and a rocker shaft support portion (67) integrally formed with the extension portion to support the end portion of the rocker shaft. It is characterized by having.

  According to this configuration, when the first housing supports the intake side rocker shaft, a part of the rocker shaft support portion provided in the cylinder head to support the intake side rocker shaft can be omitted. Thereby, the space which arrange | positions a 1st housing in a valve operating chamber is ensured.

  According to the above configuration, in the internal combustion engine, the stability of the coupling between the auxiliary machine driven by the camshaft and the cylinder head can be improved.

Perspective view showing the superstructure of the engine Left side view showing the superstructure of the engine Exploded perspective view of fuel injection pump Plan view showing cylinder head and lower housing A perspective view showing a cylinder head and a lower housing The top view which expands and shows the lower housing The top view which expands and shows the lower housing Front side view showing cylinder head, lower housing and upper housing IX-IX sectional view of FIG. XX sectional view of FIG. XI-XI cross section of Figure 2 XII-XII sectional view of Fig. 1 XIII-XIII sectional view of FIG.

  Embodiments in which the present invention is applied to an automobile engine will be described below in detail with reference to the drawings. The engine 1 according to this embodiment is an in-line four-cylinder four-valve DOHC type gasoline direct injection engine. In the direction shown in the figure, the traveling direction of the vehicle body is defined as the front, and the cylinder head (head cover) side with respect to the cylinder block is defined as the upper side in the cylinder axis direction. The engine 1 is disposed horizontally on the vehicle body, and the cylinder row direction (crankshaft direction) coincides with the left-right direction (vehicle width direction). In each figure, attention is paid to the cylinder head 2 of the engine 1, the head cover 3 and the fuel injection pump 4 coupled to the upper end of the cylinder head 2, and the cylinder block and the like coupled to the lower end of the cylinder head 2 are omitted.

  As shown in FIGS. 1-4, the cylinder head 2 has the substantially rectangular parallelepiped lower part extended in the left-right direction, and the box-shaped upper part provided in the upper end of the lower part. At the bottom of the cylinder head are four combustion chambers (not shown) that open to the lower surface of the cylinder head 2, exhaust ports (not shown) that extend forward from each combustion chamber, and rearward from each combustion chamber. An intake port 6 is formed in the rear side surface. Each exhaust port is continuous with an exhaust collecting chamber 8 formed in the lower part of the cylinder head 2, and the exhaust collecting chamber 8 has a front end (downstream end) opened on the front side surface of the cylinder head 2. As shown in FIG. 4, the upper portion of the cylinder head 2 includes a front edge wall 11, a rear edge wall 12, a left edge wall 13, and a right edge wall that are erected upward along the lower edge of the cylinder head 2. 14 and a bottom wall 15 that forms the upper surface of the lower portion define a substantially rectangular parallelepiped box-shaped valve chamber 16 that opens upward. At the upper ends of the front edge wall 11, the rear edge wall 12, the left edge wall 13 and the right edge wall 14, a coupling surface 17 facing upward is formed. As will be described in detail later, the head cover 3 and the fuel injection pump 4 are fastened to the coupling surface 17 so as to cover the upper part of the valve operating chamber 16.

  As shown in FIG. 4, an injector hole 21 into which an injector (not shown) is inserted, a plug hole 22 into which an ignition plug (not shown) is inserted, and an intake valve and an exhaust valve (not shown) are inserted into the bottom wall 15 of the cylinder head 2. A valve hole 23 is formed. The injector hole 21, plug hole 22, and valve hole 23 are each in communication with the combustion chamber.

  As shown in FIGS. 3 and 4, a plurality of intake-side rocker shaft bearings 25 are integrally projected from the rear portion of the bottom wall 15. An intake side rocker shaft 26 is supported on the intake side rocker shaft bearing 25. An intake side rocker arm 27 to which an intake valve is connected is pivotally supported on the intake side rocker shaft 26 so as to freely rotate (turn). A semicircular recess is formed at the protruding end (upper end) of the intake-side rocker shaft bearing 25, and an intake-side cam cap 28 is fastened to cover the recess. The protruding end of the intake side rocker shaft bearing 25 and the intake side cam cap 28 form an intake side camshaft bearing 29. An intake side camshaft 30 is supported on the intake side camshaft bearing 29.

  A plurality of exhaust-side rocker shaft bearings 32 project integrally from the front portion of the bottom wall 15. An exhaust side rocker shaft 33 is supported on the exhaust side rocker shaft bearing 32. An exhaust side rocker arm 34 connected to an exhaust valve is rotatably supported on the exhaust side rocker shaft 33. A semicircular recess is formed at the protruding end (upper end) of the exhaust-side rocker shaft bearing 32, and an exhaust-side cam cap 35 is fastened so as to cover the recess. The protruding end of the exhaust side rocker shaft bearing 32 and the exhaust side cam cap 35 form an exhaust side camshaft bearing 36. An exhaust side camshaft 37 is rotatably supported by the exhaust side camshaft bearing 36.

  The intake side camshaft 30, the exhaust side camshaft 37, the intake side rocker shaft 26, and the exhaust side rocker shaft 33 each extend in the longitudinal direction (left-right direction) of the cylinder head 2. An intake side cam 38 that drives the intake side rocker arm 27 is formed on the intake side camshaft 30, and an exhaust side cam 39 that drives the exhaust side rocker arm 34 is formed on the exhaust side camshaft 37. The intake side camshaft 30 and the exhaust side camshaft 37 are rotated by a crankshaft via a timing belt (chain) (not shown).

  As shown in FIG. 3, the fuel injection pump 4 includes a pump main body 41, a lower housing (first housing) 42 and an upper housing (second housing) 43 for supporting the pump main body 41 on the cylinder head 2. doing. As shown in FIGS. 3 and 8, the lower housing 42 extends upward from an appropriate position at the left end of the left edge wall 13, the front edge wall 11 and the rear edge wall 12, and the left end of the bottom wall 15. It is fastened to a plurality of protruding bosses 44 and is disposed above the left end of the cylinder head 2 and protrudes to the left outward of the cylinder head 2 beyond the left edge wall 13. The upper housing 43 is fastened to the lower housing 42 so as to cover the upper portion of the lower housing 42. The cylinder head 2, the lower housing 42, and the upper housing 43 are fastened by passing through the lower housing 42 and the upper housing 43 and screwing into the cylinder head 2 or through the upper housing 43 and screwing into the lower housing 42. Is done by Bolt.

  A lower housing recess 46, which is a recess opening upward, is formed on the upper surface of the front portion of the lower housing 42 and corresponding to the extended line of the exhaust camshaft 37. On the lower surface of the upper housing 43 and corresponding to the lower housing recess 46, an upper housing recess 47 that is a recess opening downward is formed (see FIG. 12). The lower housing recess 46 and the upper housing recess 47 are combined with each other to define one housing chamber 48. The housing chamber 48 is open on both the left and right sides, and the left side is closed by a cap 49 (see FIG. 1). As a result, the housing chamber 48 is open at a portion corresponding to the exhaust side camshaft 37 on the left side.

  As shown in FIG. 3, the exhaust-side camshaft 37 has an extension 51 that is coaxially and integrally formed at the left end thereof. The extension 51 enters the housing chamber 48. The protruding end (left end) of the extension portion 51 is disposed to the left of the left edge wall 13 in the housing chamber 48.

  As shown in FIGS. 3 and 9, a first bearing lower portion 53 that forms the lower half of the bearing that rotatably supports the extension 51 is integrally formed at the right end portion of the lower housing recess 46 of the lower housing 42. ing. A first cam cap 54 that forms the upper half of the bearing is bolted to the first bearing lower portion 53, and the extension portion 51 is rotatably supported between the first bearing lower portion 53 and the first cam cap 54. That is, the first bearing lower portion 53 and the first cam cap 54 constitute a first bearing that supports the extension portion 51. A portion of the extension portion 51 supported by the first bearing lower portion 53 and the first cam cap 54 is referred to as a first journal portion 55.

  The portion of the lower housing recess 46 of the lower housing 42 that is located to the left of the first bearing lower portion 53 and that is located to the right of the outer surface of the left edge wall 13 of the cylinder head 2 (that is, viewed from above). The second bearing lower portion 56 that forms the lower half of the bearing that rotatably supports the extension 51 is formed integrally with the cylinder head 2. A second cam cap 57 that forms the upper half of the bearing is bolted to the second bearing lower portion 56, and the extension portion 51 is rotatably supported between the second bearing lower portion 56 and the second cam cap 57. That is, the second bearing lower portion 56 and the second cam cap 57 constitute a second bearing that supports the extension portion 51. A portion of the extension portion 51 supported by the second bearing lower portion 56 and the second cam cap 57 is referred to as a second journal portion 58.

  A portion of the extension portion 51 located on the left side of the second journal portion 58 is cantilevered by the second bearing lower portion 56 and the second cam cap 57 and drives the fuel injection pump 4 on the outer peripheral surface thereof. A pump drive cam (auxiliary drive cam) 61 is formed. As shown in FIG. 9, the pump drive cam 61 is disposed on the left side of the left edge wall 13 of the cylinder head 2. The pump drive cam 61 is rotatable in the housing chamber 48 without interfering with the wall surfaces of the lower housing recess 46 and the upper housing recess 47.

  A disc-shaped thrust plate 62 protruding outward in the radial direction is formed in a portion between the first journal portion 55 and the second journal portion 58 of the extension portion 51. The thrust plate 62 has a stop surface facing the thrust direction (left-right direction) of the exhaust side camshaft 37 on the left side and the right side, and a protrusion 63 protruding radially outward at the peripheral edge thereof. . As shown in FIG. 7, in a portion between the first bearing lower portion 53 and the second bearing lower portion 56 of the lower housing 42, a thrust plate receiving groove that rotatably receives a part (lower end portion) of the thrust plate 62. 64 is recessed. The thrust plate 62 abuts against the side wall of the thrust plate receiving groove 64 at the left and right side stop surfaces to determine the thrust direction position of the exhaust camshaft 37.

  As shown in FIG. 9, an extension portion 66 extending downward in the valve operating chamber 16 is formed at the right end portion of the lower housing 42 and substantially below the first bearing lower portion 53. The lower end of the extending portion 66 extends downward from the coupling surface 17 of the left edge wall 13 and is disposed close to the bottom wall 15. The extending portion 66 is formed with an exhaust-side rocker shaft support portion 67 having a bottomed cylindrical shape that opens toward the right. The left end of the exhaust side rocker shaft 33 is inserted into the exhaust side rocker shaft support portion 67 and is coupled so as not to rotate.

  As shown in FIGS. 5 and 6, a third bearing lower portion 68 is formed at the right end portion of the lower housing 42 and corresponding to the intake side camshaft 30. A third cam cap 69 is fastened to the third bearing lower portion 68, and the left end of the intake side camshaft 30 is rotatably supported between the third bearing lower portion 68 and the third cam cap 69. That is, the third bearing lower portion 68 and the third cam cap 69 constitute a third bearing that supports the intake side camshaft 30. Below the third bearing lower portion 68 of the lower housing 42, an extension portion 71 extending downward in the valve operating chamber 16 is formed, and the extension portion 71 has a bottom having an opening toward the right. An intake side rocker shaft support portion 72 having a cylindrical shape is formed. The left end of the intake side rocker shaft 26 is inserted into the intake side rocker shaft support portion 72 and is coupled so as not to rotate.

  As shown in FIGS. 5 and 6, on the bottom surface 74 of the lower housing recess 46, a coupling seat 75 is provided protruding from the side of the rear end of the second bearing lower portion 56 to the left and rearward. . The coupling seat 75 extends substantially behind the pump drive cam 61 so as not to interfere with the pump drive cam 61. The upper surface of the coupling seat 75 is formed in the same plane as the coupling surface with the second cam cap 57 of the second bearing lower portion 56, and the coupling seat distal end portion 76, which is the distal end portion thereof, is a coupling surface that abuts the upper housing 43. It has become. A coupling seat base end portion 77 that is a base end portion of the upper surface of the coupling seat 75 is covered with a second cam cap extending portion 78 extending from the second cam cap 57.

  As shown in FIGS. 1 and 3, the upper housing 43 has a sensor hole 81 that communicates a portion of the upper housing recess 47 facing the thrust plate 62 and the upper surface of the upper housing 43. A rotation sensor (not shown) that detects the rotation position and rotation speed of the exhaust camshaft 37 by detecting the protrusion 63 of the thrust plate 62 is inserted into the sensor hole 81 and coupled thereto. Thereby, the thrust plate 62 functions as a pulsar plate that generates a pulse signal corresponding to the rotation by the protrusion 63.

  As shown in FIGS. 11 and 12, the upper housing 43 has a plunger support hole 82 that is a through hole having a circular cross section that communicates the inner surface (lower surface) of the upper housing recess 47 and the upper surface of the upper housing 43. Yes. The plunger support hole 82 is disposed such that its axis coincides with the radial direction of the extension 51 of the exhaust camshaft 37 and is inclined with respect to the front-rear direction. In addition, when the engine 1 is disposed with an inclination, the axis of the plunger support hole 82 is disposed with an inclination with respect to the horizontal direction. In the present embodiment, the axis of the plunger support hole 82 is inclined by about 45 ° with respect to the front-rear direction. The outer end of the plunger support hole 82 is enlarged in steps.

  As shown in FIGS. 11 and 12, the pump body 41 is a known plunger pump, and although detailed illustration is omitted, a pump body casing 85 having a fuel passage (not shown) and a pump body casing 85 are provided. And a plunger 86 provided so as to be able to appear and retract. The pump body 41 draws fuel into the fuel oil passage in the pump body casing 85 when the plunger 86 protrudes from the pump body casing 85, and pressurizes the fuel when the plunger 86 enters the pump body casing 85. Then, the pump is sent out of the pump body casing 85.

  A roller holder 88 that rotatably supports the roller 87 is coupled to the tip of the plunger 86. The roller holder 88 is supported from a disc-shaped substrate 89 coupled to the tip of the plunger 86, a pair of support plates 90 projecting in a direction opposite to the plunger 86 side of the substrate 89, and a peripheral portion of the substrate 89. It has a cylindrical skirt 91 protruding in a direction opposite to the plate 90 side. A support shaft 92 is spanned between the pair of support plates 90, and a roller 87 is rotatably supported on the support shaft 92. The substrate 89 is formed with a plurality of oil through holes 84 penetrating along the advance / retreat direction of the plunger 86. A compression coil spring 93 is interposed between the substrate 89 and the pump body casing 85. The compression coil spring 93 urges the plunger 86 in a direction protruding from the pump body casing 85 via the roller holder 88.

  The plunger 86 is disposed in the plunger support hole 82, and the pump body casing 85 is fastened to the upper housing 43 in a state where a part of the pump body casing 85 is fitted to the outer end of the plunger support hole 82. The plunger 86 extends obliquely downward in the plunger support hole 82, and the roller 87 is disposed at the lowermost end. At this time, the skirt 91 of the roller holder 88 is in sliding contact with the inner wall of the plunger support hole 82, a part of the roller holder 88 and the roller 87 protrude into the housing chamber 48, and the roller 87 strikes (rolls) against the pump drive cam 61. )doing. A guide groove extending in the axial direction is formed in the plunger support hole 82, and a guide protrusion that protrudes into the guide groove is formed on the outer peripheral surface of the skirt 91. The rotation position of the roller holder 88 relative to the plunger support hole 82 is determined by the guide convex portion sliding in the guide groove. When the exhaust side camshaft 37 rotates, the plunger 86 is advanced and retracted with respect to the pump body casing 85 by the pump drive cam 61, and the pump body 41 pumps fuel. As described above, the fuel injection pump 4 that is driven according to the rotation of the exhaust camshaft 37 is configured.

  As shown in FIG. 1, the head cover 3 extends from the right end portion to the left end portion of the valve operating chamber 16 of the cylinder head 2, and the left edge portion 94 extends on the upper surface of the upper housing 43. The right edge of 43 is covered. That is, the head cover 3 is coupled to the upper housing 43 so as to overlap from above. A liquid packing is interposed between the left edge portion 94 of the head cover 3 and the upper right edge portion of the upper housing 43 to provide a seal. Thus, the valve operating chamber 16 is covered with the head cover 3 and the fuel injection pump 4.

  As shown in FIG. 10, at the left end portion of the cylinder head 2, a head side blow-by passage 95 that is continuous with a case-side blow-by passage (not shown), which is a blow-by gas passage formed in the crankcase, is formed. One end of the case side blow-by passage communicates with a crank chamber (not shown) of the crank case, and the other end opens at an upper end surface that is a coupling surface with the cylinder head 2. The head side blow-by passage 95 extends in the vertical direction in the left edge wall 13, and the lower end thereof opens to the lower end surface of the cylinder head 2 and communicates with the case side blow-by passage, while the upper end thereof is the left edge wall 13. It opens to the coupling surface 17 which is the upper end surface.

  The lower housing 42 extends in the vertical direction, and the lower end thereof opens to the lower end surface of the lower housing 42 (the surface joined to the coupling surface 17 of the left edge wall 13) and communicates with the head side blow-by passage 95, A lower blow-by passage 96 having an upper end opened on the upper end surface of the lower housing 42 (the coupling surface with the upper housing 43) is formed. As shown in FIGS. 3 to 6, the lower side blow-by passage 96 is disposed to the right of the pump drive cam 61 in the left-right direction, and is disposed between the first bearing lower portion 53 and the second bearing lower portion 56. ing. The lower blow-by passage 96 is disposed between the exhaust camshaft 37 and the intake camshaft 30 (between the first bearing lower portion 53 and the third bearing lower portion 68) in the front-rear direction. More specifically, as shown in FIG. 6, the upper end of the lower blow-by passage 96 is disposed behind the thrust plate 62 so as not to overlap the thrust plate 62 when viewed from above.

  As shown in FIG. 10, the upper housing 43 extends in the up-down direction, and the lower end thereof opens to the lower end surface of the upper housing 43 (the coupling surface with the lower housing 42). An upper side blow-by passage 97 is formed which communicates with the upper end of 96, while the upper end is the upper end surface of the upper housing 43, and is open at a portion covered by the left edge portion 94 of the head cover 3.

  A box-shaped breather case 98 that opens downward is coupled to the front side of the upper surface of the head cover 3. The breather case 98 extends in the left-right direction, and defines a gas-liquid separation chamber (breather chamber) 99 between the top surface of the head cover 3. A plurality of baffle plates (not shown) protrude from the inner surface of the breather case 98 to remove oil mist from blow-by gas passing through the inside. The left edge portion 94 of the head cover 3 has one end that opens to the coupling surface with the upper housing 43 and communicates with the upper blow-by passage 97, while the other end opens to a portion covered with the breather case 98. A cover side blow-by passage 101 communicating with the separation chamber 99 is formed. With the above configuration, the blow-by gas in the crank chamber sequentially passes through the case-side blow-by passage, the head-side blow-by passage 95, the lower-side blow-by passage 96, the upper-side blow-by passage 97, and the cover-side blow-by passage 101, and the gas-liquid separation chamber 99. To be supplied. After the oil is separated in the gas-liquid separation chamber 99, the blow-by gas is introduced into an intake pipe (not shown) that passes through a PCV valve (not shown) and communicates with the intake port 6.

  Next, the lubrication structure of the fuel injection pump 4 will be described. As shown in FIG. 9, an exhaust side camshaft oil passage 111 extending in the axial direction is formed inside the exhaust side camshaft 37 and its extension 51. The left end of the exhaust camshaft oil passage 111 is closed by a cap 112 at the end of the extension 51. The first journal portion 55 is formed with a first communication oil passage 113 extending from the outer peripheral surface thereof to the exhaust side camshaft oil passage 111. An annular first journal oil groove 114 extending in the circumferential direction is formed in a portion of the outer peripheral surface of the first journal portion 55 where the first communication oil passage 113 is opened. As shown in FIG. 7 and FIG. 9, the portion of the first bearing lower portion 53 that is in sliding contact with the first journal portion 55 and facing the first journal oil groove 114 has a periphery of the first journal portion 55. A first bearing lower oil groove 115 extending in the direction is formed.

  As shown in FIG. 9, the second journal portion 58 is formed with a second communication oil passage 117 extending from the outer peripheral surface thereof to the exhaust side camshaft oil passage 111. An annular second journal oil groove 118 extending in the circumferential direction is formed in a portion of the outer peripheral surface of the second journal portion 58 where the second communication oil passage 117 is opened. As shown in FIGS. 7 and 9, the portion of the second bearing lower portion 56 that is in sliding contact with the second journal portion 58 and that faces the second journal oil groove 118 has a peripheral surface of the second journal portion 58. A second bearing lower oil groove 119 extending in the direction is formed.

  As shown in FIGS. 7 and 9, a pair of left and right oil grooves 121 projecting from the thrust plate receiving groove 64 in the left-right direction are formed in an intermediate portion in the front-rear direction of the thrust plate receiving groove 64. The thrust plate 62 is received away from the bottom of the thrust plate receiving groove 64, and the left and right oil grooves 121 are continuous via the thrust plate receiving groove 64.

  As shown in FIG. 6, one end of the second bearing lower portion 56 and the second cam cap 57 are connected to the second bearing lower oil groove 119 and the other end extends to the coupling seat base end portion 77. A coupling seat side oil groove 123 is formed. As shown in FIG. 13, the coupling surface of the second cam cap 57 and the second cam cap extension 78 with the second bearing lower portion 56 and the coupling seat base end 77 extends along the coupling seat side oil groove 123. A cap side oil groove 124 is formed. In the joint seat base end portion 77 of the joint seat side oil groove 123, an oil in the joint seat is formed inside the joint seat 75 and has one end opened on the upper surface of the joint seat distal end portion 76 of the joint seat 75. The other end of the path 125 is open. As shown in FIG. 13, the coupling seat oil passage 125 extends from the coupling seat base end portion 77 to the lower side of the coupling seat distal end portion 76, and extends downward from the coupling seat distal end portion 76. And a second linear passage. In this way, the passage in the joint seat 75 can be easily processed by using the joint seat oil passage 125 as a V-shaped passage combining two straight passages.

  One end of the upper housing oil passage 127 that communicates with the oil passage 125 in the coupling seat is opened at a portion of the upper housing 43 that is coupled to the distal end portion 76 of the coupling seat. The other end of the upper housing oil passage 127 opens into the plunger support hole 82.

  In the lubricating structure of the fuel injection pump 4 configured as described above, the exhaust side camshaft oil of the exhaust side camshaft 37 is supplied from a known oil pump (not shown) as an engine accessory via the cylinder block and the cylinder head 2 and the like. Lubricating oil is supplied to the path 111. The lubricating oil supplied to the exhaust-side camshaft oil passage 111 is supplied to the outer peripheral surface of the first journal portion 55 through the first communication oil passage 113, the first journal oil groove 114, and the first bearing lower oil groove 115. The lubricating oil supplied to the exhaust-side camshaft oil passage 111 is supplied to the outer peripheral surface of the second journal portion 58 through the second communication oil passage 117, the second journal oil groove 118, and the second bearing lower oil groove 119. The The lubricating oil supplied to the outer peripheral surfaces of the first journal portion 55 and the second journal portion 58 and overflowing from the first bearing lower portion 53 and the second bearing lower portion 56 is supplied to the thrust plate receiving groove 64 by the oil groove 121. The

  The lubricating oil supplied to the second bearing lower oil groove 119 passes through the joint seat side oil groove 123, the cap side oil groove 124, the joint seat oil passage 125, and the upper housing oil passage 127 and is supplied to the plunger support hole 82. Is done. The lubricating oil supplied to the plunger support hole 82 is supplied to the outer peripheral surface of the skirt 91 of the roller holder 88, and is pushed out between the outer peripheral surface of the skirt 91 and the inner peripheral surface of the plunger support hole 82. Move to the distal end and proximal end. The lubricating oil pushed out to the front end side of the roller holder 88 flows down to the surface of the roller 87 through the surfaces of the support plate 90 and the support shaft 92 by gravity and the forward and backward movement of the plunger 86, and the cam surface of the pump drive cam 61. To be supplied. Further, the lubricating oil that has moved to the base end side of the roller holder 88 wraps around the end portion of the skirt 91 from the upper side, enters the inner peripheral surface side of the skirt 91, passes through the oil passage hole 84, and flows down onto the roller 87. To do. In this way, the plunger 86 and the pump drive cam 61 of the fuel injection pump 4 are supplied with lubricating oil through the oil passages formed in the exhaust side camshaft 37, the lower housing 42 and the upper housing 43.

  The lubricating oil supplied to the roller 87 and the pump drive cam 61 falls on the bottom surface 74 of the lower housing recess 46 and is collected. The lower housing 42 is formed with an oil discharge hole 130 that communicates a bottom surface 74 of the lower housing recess 46 and a lower surface of the lower housing 42 and a portion disposed in the valve operating chamber 16. Thereby, the lubricating oil collected on the bottom surface 74 of the lower housing recess 46 is discharged into the valve operating chamber 16 through the oil discharge hole 130. Although not shown, the cylinder head 2 and the cylinder block are formed with an oil return passage for returning the lubricating oil from the valve operating chamber 16 to an oil pan provided at the lower portion of the cylinder block. In another embodiment, the oil discharge hole 130 may communicate directly with the oil return passage of the cylinder head 2 without communicating with the valve operating chamber 16.

  In the embodiment described above, the lower housing 42 of the fuel injection pump 4 is fastened to the coupling surface 17 facing the upper side of the left edge wall 13, the front edge wall 11, and the rear edge wall 12 of the cylinder head 2. The cylinder head 2 is disposed so as to protrude onto the valve operating chamber 16. Since the fuel injection pump 4 receives a load from the pump drive cam 61 of the exhaust side camshaft 37 in one radial direction of the exhaust side camshaft 37, the fuel injection pump 4 is coupled to the cylinder head 2 from above, so that the pump drive cam 61 It is possible to efficiently resist the load received from the. That is, the coupling stability between the fuel injection pump 4 and the cylinder head 2 is improved, and the possibility that a mouth opening occurs between the lower housing 42 and the cylinder head 2 is reduced.

  In addition, since the first bearing lower portion 53 and the second bearing lower portion 56 that support the exhaust camshaft 37 are formed integrally with the lower housing 42, the lower housing 42 and the upper housing 43 are connected to the plunger 86 and the pump main body from the pump drive cam 61. While receiving a load via 41, a reaction force is received from the plunger 86 via the pump drive cam 61, the exhaust side camshaft 37, the first bearing lower portion 53 and the second bearing lower portion 56. The direction of the reaction force is a direction in which the lower housing 42 is pressed against the coupling surface 17 side of the cylinder head 2, so that the connection between the lower housing 42 and the cylinder head 2 becomes stronger and the possibility of opening of the mouth is reduced. To do.

  The lower housing 42 includes end portions of the third bearing lower portion 68 that supports the end portion of the intake side camshaft 30, the intake side rocker shaft support portion 72 that supports the end portion of the intake side rocker shaft 26, and the exhaust side rocker shaft 33. Since the exhaust-side rocker shaft support portion 67 to be supported is integrally provided, even if the exhaust-side rocker shaft support portion 67 is extended above the cylinder head 2, that is, into the valve operating chamber 16, the cylinder head 2 is not enlarged. That is, it is not necessary to provide a space for disposing the lower housing 42 in the valve operating chamber 16.

  Further, a lower housing 42 and an upper housing 43 are disposed between the cylinder head 2 and the head cover 3 in the vertical direction, and a lower blowby passage 96 and an upper blowby passage that penetrate the lower housing 42 and the upper housing 43 in the vertical direction. Since 97 is provided, the engine 1 can be made compact. In particular, the lower side blowby passage 96 and the upper side blowby passage 97 are between the intake side camshaft 30 and the intake side rocker shaft 26, and the exhaust side camshaft 37 and the exhaust side rocker shaft 33 in the front-rear direction, Since it is provided in a dead space between the first bearing lower portion 53 and the second bearing lower portion 56 in the left-right direction, the engine 1 can be made compact. Further, the lower side blow-by passage 96 and the upper side blow-by passage 97 are arranged at the substantially central portions of the lower housing 42 and the upper housing 43, and abut against (join) the cylinder head 2 at this portion. The coupling stability of the housing 42 to the cylinder head 2 is improved.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. In the present embodiment, the fuel injection pump 4 is illustrated as an example of the engine auxiliary machine attached to the cylinder head 2, but instead of the fuel injection pump 4, other engine auxiliary machines such as a water pump and an air compressor are applied. Also good.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder head, 3 ... Head cover, 4 ... Fuel injection pump, 11 ... Front edge wall, 12 ... Rear edge wall, 13 ... Left edge wall, 14 ... Right edge wall, 16 ... Valve-operating chamber, 17 DESCRIPTION OF SYMBOLS ... Connection surface, 37 ... Exhaust side camshaft, 41 ... Pump body, 42 ... Lower housing (first housing), 43 ... Upper housing (second housing), 46 ... Lower housing recess, 47 ... Upper housing recess, 48 ... Housing chamber 51. Extension portion 53 53 Lower first bearing 54 54 First cam cap 55 First journal portion 56 Second bearing lower portion 57 Second cam cap 58 58 Second journal portion 61 ... pump drive cam, 62 ... thrust plate, 63 ... projection, 64 ... thrust plate receiving groove, 66 ... extension part, 67 ... exhaust side rocker shaft support part, 68 ... third bearing lower part, 69 ... first Cam cap, 71 ... extension portion, 72 ... intake-side rocker shaft support portion, 74 ... bottom surface, 75 ... coupling seat, 76 ... coupling seat distal end portion, 77 ... coupling seat base end portion, 78 ... second cam cap extension , 81 ... sensor hole, 82 ... plunger support hole, 85 ... pump main body casing, 86 ... plunger, 95 ... head side blowby passage, 96 ... lower side blowby passage, 97 ... upper side blowby passage, 101 ... cover side blowby passage 111 ... Exhaust side camshaft oil passage, 113 ... First communication oil passage, 114 ... First journal oil groove, 115 ... First bearing lower oil groove, 117 ... Second communication oil passage, 118 ... Second journal oil groove DESCRIPTION OF SYMBOLS 119 ... 2nd bearing lower oil groove, 121 ... Oil groove, 123 ... Coupling seat side oil groove, 124 ... Cap side oil groove, 125 ... Coupling seat oil passage, 127 ... Upper housing oil passage, 130 ... Yl discharge hole

Claims (9)

A cylinder head having a valve operating chamber on one side;
A camshaft rotatably arranged in the valve train chamber and having an extension coaxially and integrally at an end;
The cylinder disposed between the cylinder head and the extension portion, coupled to the end surface of the cylinder head on the valve operating chamber side, and on the side where the extension portion is disposed in the extending direction of the camshaft A first housing protruding outward beyond the end of the head;
A second housing coupled to the first housing and defining a housing chamber for receiving the extension between the first housing;
An auxiliary machine that includes a plunger that enters the housing chamber, is supported by the second housing, and is driven by the advance and retreat of the plunger;
An auxiliary drive cam formed on the extension and moving the plunger back and forth;
An auxiliary machine mounting structure for an internal combustion engine, comprising: a first bearing provided integrally with the first housing and rotatably supporting the extension portion.   In order to rotatably support a portion between the portion of the extension portion supported by the first bearing and the accessory drive cam, a second bearing is provided integrally with the first housing. 2. The auxiliary machine mounting structure for an internal combustion engine according to claim 1, wherein The second bearing is disposed inward of the cylinder head from the end of the cylinder head in the extending direction of the camshaft.
3. The internal combustion engine according to claim 2, wherein the auxiliary machine drive cam is disposed outward of the cylinder head in the extending direction of the cam shaft rather than the end of the cylinder head. Auxiliary mounting structure.   4. The auxiliary equipment mounting structure for an internal combustion engine according to claim 2, wherein a portion of the extension portion provided with the auxiliary equipment drive cam is cantilevered by the second bearing. 5. A thrust plate having an abutment surface facing the extending direction of the camshaft projects between a portion of the extension portion supported by the first bearing and a portion supported by the second bearing. Established,
The thrust plate receiving groove for receiving the thrust plate rotatably in the rotation direction of the camshaft is formed in the first housing. A structure for mounting an auxiliary machine for an internal combustion engine according to claim 1.   6. The internal combustion engine according to claim 5, wherein the first housing has an oil groove that guides lubricating oil overflowing from at least one of the first bearing and the second bearing to the thrust plate receiving groove. Auxiliary equipment mounting structure. The thrust plate has a protrusion protruding in a radial direction,
The auxiliary machine mounting structure for an internal combustion engine according to claim 5 or 6, wherein a sensor for detecting the protrusion is provided in the second housing. The camshaft rotatably disposed in the valve operating chamber and having the extension portion coaxially and integrally at an end thereof is an exhaust side camshaft,
Wherein the valve operating chamber, before Symbol exhaust camshaft and parallel to intake air side cam shaft rotatably supported,
The auxiliary machine for an internal combustion engine according to any one of claims 1 to 7, wherein the first housing has an intake-side bearing that rotatably supports an end portion of the intake camshaft. Mounting structure. The valve chamber is surrounded by an edge wall extending along a side edge of the cylinder head,
The end surface of the cylinder head on the valve operating chamber side is formed by a protruding end of the edge wall;
A rocker shaft extending in parallel with the camshaft is disposed in the valve train chamber,
The first housing is coupled to the end face , and extends to the valve operating chamber, and a rocker shaft formed integrally with the extension to support the end of the rocker shaft. The auxiliary machine mounting structure for an internal combustion engine according to any one of claims 1 to 8, further comprising a support portion.

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