JP6651844B2 - cylinder head - Google Patents

Description

  The present invention relates to a cylinder head of an engine mounted on a vehicle.

  A cylinder head of a direct injection type diesel engine (hereinafter, referred to as an engine) is assembled with an injector for injecting fuel into a combustion chamber of the cylinder, an intake valve for opening and closing the combustion chamber, an exhaust valve, and the like. For example, an injector is mounted upright on a cylinder head of an engine disclosed in Patent Document 1. In this case, an injector supporting portion (boss) is provided upright from the bottom wall portion in the cylinder head, and the injector is inserted into and supported by an injector insertion hole (boss hole) of the injector supporting portion. In the cylinder head, an intake valve is provided on one side in a direction perpendicular to the arrangement direction of the cylinders with the injector interposed therebetween (the width direction of the engine), and an exhaust valve is provided on the other side in communication with the combustion chamber.

  By the way, conventionally, the size and weight of the engine have been reduced. One of the measures for this is to reduce the overall width of the engine. For example, if the axial distance between the injector and the intake valve and the exhaust valve is reduced, the overall width of the cylinder head and, consequently, the engine can be reduced accordingly.

Japanese Patent No. 3846436

  When the injector is supported by being inserted into the injector insertion hole of the injector support, the intake valve and the exhaust valve cannot be brought close to the axis of the injector by the thickness of the injector support (the difference between the outer and inner diameters). Therefore, there is a possibility that the thickness of the injector support portion limits the reduction of the overall width of the engine.

  For this reason, even when the injector is supported by the injector support portion, it is desired to reduce the overall width of the engine and reduce the size and weight.

  The cylinder head of the present invention includes a bottom wall disposed on the cylinder block side of the engine, and an outer peripheral wall rising from a peripheral edge of the bottom wall. An injector support for supporting the injector is provided on the bottom wall. The injector support portion has an injector insertion hole into which the injector is inserted, a positioning portion that positions the injector inserted into the injector insertion hole, and an opening that passes through the outer peripheral portion of the injector insertion hole avoiding the positioning portion. ing.

  In this case, the opening is disposed at a position that does not overlap with the positioning portion in the injector insertion direction.

  The cylinder head has a beam portion in addition to the bottom wall portion and the outer peripheral wall portion. The beam section is continuous with the injector support section and partitions the space surrounded by the outer peripheral wall into the intake valve side and the exhaust valve side, and subdivides the partitioned intake valve side space and exhaust valve side space respectively. ing. In such a cylinder head, the opening is open toward the space on the intake valve side.

  For example, the openings are subdivided by the beam portion and opened one by one toward the space on the side of the adjacent intake valve.

  In addition, the positioning part is arrange | positioned at the front side and the back side in the insertion direction of an injector with space. For example, the positioning portion may be a portion of the injector insertion hole whose hole diameter is substantially the same as the outer diameter of the injector. In this case, the positioning portion on the front side can have a larger hole diameter than the positioning portion on the back side.

  According to the cylinder head of the present invention, the overall width of the engine can be reduced, and the size and weight can be reduced.

FIG. 1 is a diagram schematically showing an engine including a cylinder head according to an embodiment of the present invention. FIG. 1 is a perspective view showing a cylinder head according to an embodiment of the present invention from the upper left front. FIG. 1 is a plan view showing a cylinder head according to an embodiment of the present invention from the front. FIG. 1 is a plan view showing a cylinder head according to an embodiment of the present invention from above. The figure which shows the cross section of the arrow A41 part of the injector support part of the cylinder head shown in FIG. 4 from the arrow direction. The figure which shows the cross section of the arrow A42 part of the injector support part of the cylinder head shown in FIG. 4 from the arrow direction. The figure which shows the cross section of the arrow A43 part of the injector support part of the cylinder head shown in FIG. 4 from the arrow direction. The figure which shows the cross section of the arrow A31 part of the cylinder head shown in FIG. 3 from the arrow direction. FIG. 9 is an enlarged view showing an injector insertion hole and a positioning portion of the injector support shown in FIG. 8. The figure which shows the cross section of the arrow A32 part of the cylinder head shown in FIG. 3 from the arrow direction. The elements on larger scale of FIG. The figure which shows the cross section of the arrow A33 part of the cylinder head shown in FIG. 3 from the arrow direction. FIG. 13 is a partially enlarged view of FIG. 12.

  Hereinafter, a cylinder head according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram schematically showing an engine 1 including a cylinder head 4 of the present embodiment. The engine 1 includes an oil pan 2, a cylinder block 3, a cylinder head 4, a rocker cover 5, a front cover 6, and a crank pulley 7. Hereinafter, the crank pulley 7 side of the engine 1 is referred to as a front side (front) of the engine 1 and the opposite side is referred to as a rear side (rear). The direction of gravity with the cylinder (not shown) arranged vertically is the lower side (lower) of the engine 1 and the opposite direction is the upper side (upper). A direction perpendicular to both the front-rear direction and the up-down direction is defined as the left-right direction, and the left-right direction is determined from the rear to the front. The left-right direction corresponds to the width direction of the engine 1.

  The engine 1 is an in-line four-cylinder diesel engine. However, it is not limited to this. Each cylinder (cylinder) is arranged in the cylinder block 3 in the front-rear direction.

  2 to 4 show the configuration of the cylinder head 4. FIG. FIG. 2 is a perspective view showing the cylinder head 4 from the upper left front. 3 is a plan view showing the cylinder head 4 from the front, and FIG. 4 is a plan view showing the cylinder head 4 from above.

  The cylinder head 4 is a casting made of a metal such as an aluminum alloy, and is provided on the cylinder block 3 and has an opening at the top. The cylinder head 4 is fixed to the cylinder block 3 by a head bolt 8. A rocker cover 5 is attached to the opening of the cylinder head 4.

  The cylinder head 4 includes a bottom wall portion 41, an outer peripheral wall portion 42, and a beam portion 45 (a first beam portion 43 and a second beam portion 44).

  The bottom wall portion 41 is disposed above the cylinder block 3 and serves as a base of the cylinder head 4. The bottom wall 41 is longer in the front-rear direction than in the left-right direction.

  The outer peripheral wall portion 42 is a frame-shaped body that rises from the peripheral edge of the bottom wall portion 41 and is continuous in the circumferential direction. As a result, a space S in which the intake / exhaust system is arranged is formed inside the outer peripheral wall portion 42. The outer peripheral wall portion 42 is configured to include an outer vertical wall portion 42a and an outer horizontal wall portion 42b continuous with the outer vertical wall portion 42a. The outer vertical wall portions 42a are provided in pairs at predetermined intervals in the left-right direction, and extend substantially along the front-rear direction. The outer horizontal wall portions 42b are provided in pairs at predetermined intervals in the front-rear direction, extend substantially along the left-right direction, and are continuous with both ends of the outer vertical wall portion 42a. Since the bottom wall portion 41 is long in the front-rear direction, the interval between the outer vertical wall portions 42a is smaller than the interval between the outer horizontal wall portions 42b.

  The beam 45 includes a first beam 43 and a second beam 44. The first beam portion 43 is disposed between the outer vertical wall portions 42a substantially parallel to the outer horizontal wall portions 42b, is continuous with the outer vertical wall portions 42a, and divides a space S surrounded by the outer peripheral wall portions 42 from above and below. They are divided into several parts. In the present embodiment, four first beams 43 divide the space S into five spaces. These first beam portions 43 are arranged at substantially equal intervals in the front-rear direction. The first beam portion 43 is disposed so as to pass through the center (axial center) of each of the combustion chambers (not shown) of the four cylinders when viewed from above and below.

  Bearing members 43i and 43e that rotatably support cam journals (not shown) of the camshafts on the intake valve side and the exhaust valve side are mounted on the upper portion of the first beam portion 43. The upper portion of the first beam portion 43 and the bearing members 43i and 43e are assembled so that a circular cam journal insertion hole 43c corresponding to the diameter of the cam journal penetrates in the front-rear direction between each other. A semi-circular recess is formed in each of the front and rear directions. Similarly, bearing members 42i and 42e that support the cam journal are also mounted on the upper portion of the front outer lateral wall portion 42b. The upper portion of the outer lateral wall portion 42b and the bearing members 42i and 42e are assembled in such a manner that a circular cam journal insertion hole 42c corresponding to the diameter of the cam journal penetrates in the front-rear direction between each other. Each of the semicircular recesses is formed when viewed from the front-back direction.

  The second beam portion 44 is provided between the outer horizontal wall portions 42b substantially in parallel with the outer vertical wall portion 42a, and crosses the first beam portion 43. The space S surrounded by the outer peripheral wall portion 42 is partitioned into two spaces Si and Se when viewed from above and below, with the second beam portion 44 as a boundary in the left-right direction. In the present embodiment, the second beam portion 44 intersects a substantially intermediate portion of the first beam portion 43 in the left-right direction, and substantially divides the space S. In this case, the second beam portions 44 are respectively bridged between the two first beam portions 43 on the front side in the front-rear direction and between the two first beam portions 43 on the rear side. I have. Of the two spaces Si and Se partitioned by the second beam portion 44, an intake system including an intake valve (not shown) is disposed in the left space Si, and an exhaust valve (not shown) is disposed in the right space Se. ) Is disposed.

  That is, the space S is partitioned into the space Si on the intake side and the space Se on the exhaust side by the second beam portion 44, and the space Si and the space Se are subdivided by the first beam portion 43, respectively.

  An injector 9 for injecting fuel into the combustion chamber of the cylinder is mounted on the cylinder head 4. In the present embodiment, four injectors 9 are assembled, one for each of the four cylinders. The bottom wall portion 41 is provided with the injector supporting portions 40 for supporting the assembled injectors 9 according to the number of the injectors 9 (four in the present embodiment).

  5 to 7 show the configuration of the injector support section 40. FIG. FIGS. 5, 6, and 7 are views showing cross sections of arrows A41, A42, and A43 in FIG. 4 from the directions of the respective arrows.

  The injector support section 40 is arranged at a portion where the first beam section 43 and the second beam section 44 intersect. That is, the first beam portion 43 and the second beam portion 44 are continuously integrated with the injector support portion 40, and extend toward the outer peripheral wall portion 42 (the outer vertical wall portion 42a and the outer horizontal wall portion 42b). are doing. Each intersection of the first beam portion 43 and the second beam portion 44 corresponds to the center (axial center) position of each combustion chamber of the four cylinders when viewed from above and below. Therefore, by arranging the injector support portion 40 at such an intersection, the injector 9 is positioned corresponding to each combustion chamber of the cylinder.

  The injector support portion 40 is a protrusion that rises vertically (upward) from the bottom wall portion 41, and inserts the injector 9 into an injector insertion hole 401 formed in the protrusion to support the injector. The injector insertion hole 401 penetrates a protrusion rising from the bottom wall portion 41 along the up-down direction, and also penetrates the bottom wall portion 41 to communicate with the combustion chamber of the cylinder.

  The injector support part 40 has a positioning part 402 for positioning the injector 9 inserted into the injector insertion hole 401, and an opening 403 penetrating the outer periphery of the injector insertion hole 401. The injector 9 inserted into the injector insertion hole 401 and positioned by the positioning portion 402 has a state in which the nozzle tip protrudes toward the combustion chamber of the cylinder. As shown in FIG. 8, the injector 9 positioned by the positioning portion 402 is prevented from falling out of the injector insertion hole 401 in a pair by a bracket 90 bolted to the second beam portion 44. I have. FIG. 8 is a diagram showing a cross section taken along arrow A31 in FIG. 3 from the direction of the arrow.

  FIG. 9 shows an enlarged view of the injector insertion hole 401 and the positioning part 402 of the injector support part 40 shown in FIG. As shown in FIG. 9, the positioning portions 402 are provided at two places. These positioning portions 402 are spaced apart from each other on the near side and the far side in the direction of inserting the injector 9 into the injector insertion hole 401, that is, on the upper side and the lower side in the vertical direction. Although the mode of the positioning section 402 is not particularly limited, in the present embodiment, a portion of the injector insertion hole 401 whose hole diameter is substantially the same as the outer diameter of the injector 9 is set as the positioning section 402.

  The injector insertion hole 401 is formed with three hole diameters from the upper side to the lower side. The first hole diameter part 401a of the upper layer part, the second hole diameter part 401b of the middle layer part, and the third hole diameter part 401c of the lower layer part are formed. Have. In these, the hole diameter is reduced in the order of the first hole diameter portion 401a, the second hole diameter portion 401b, and the third hole diameter portion 401c.

  Of the positioning portions 402, the first positioning portion 402a disposed on the near side (upper side) in the insertion direction of the injector 9 has a larger hole diameter than the second positioning portion 402b disposed on the far side (lower side). Diameter. The first positioning portion 402a corresponds to the upper end of the first hole diameter portion 401a of the injector insertion hole 401, and the second positioning portion 402b corresponds to the upper end of the second hole diameter portion 401b.

  In the injector 9, the insertion site into the injector insertion hole 401 has a tapered shape in the insertion direction, and the first insertion site 9a and the second insertion site 9b have a plurality of radial dimensions (as an example). , The injector 9 shown in FIG. 9 is reduced in two stages). The first insertion part 9a is a part inserted into the first hole diameter part 401a of the injector insertion hole 401, and the second insertion part 9b is a part inserted into the second hole diameter part 401b. The third insertion portion (the portion to be inserted into the third hole diameter portion 401c) 9c of the injector 9 has a smaller diameter than the hole diameter of the third hole diameter portion 401c.

  For this reason, when the injector 9 is inserted into the injector insertion hole 401, the maximum diameter portion 91 of the first insertion portion 9a comes into contact with the upper end portion of the first hole diameter portion 401a and the second insertion portion 9b Of the second hole diameter portion 401b contacts the upper end of the second hole diameter portion 401b. That is, the injector 9 contacts the inner surface of the injector insertion hole 401 only at the first positioning portion 402a and the second positioning portion 402b. As a result, the injector 9 is positioned and fixed at the two positions of the first positioning portion 402a and the second positioning portion 402b, and its posture is kept upright in the injector insertion hole 401.

  The opening 403 is formed so as to avoid the positioning part 402. Therefore, even if the opening 403 is formed in the injector support section 40, the positioning of the injector 9 by the positioning section 402 is not hindered. FIG. 5 shows, as an example, a configuration in which the opening 403 is arranged at a position that does not overlap with the positioning portion 402 in the insertion direction of the injector 9, that is, at a height different from the positioning portion 402 in the up-down direction.

  In the present embodiment, the opening 403 is arranged so as to open from the height H2 of the second positioning portion 402b to the height H1 of the first positioning portion 402a in the vertical direction. Specifically, the opening 403 is open in a range Hb from a height H3 of a valve spring seating surface 413, 414 described later to a height H1 of the first positioning portion 402a. The height H1 is a distance from the position of the communication opening 401d of the injector insertion hole 401 with the combustion chamber to the lowest position of the first positioning portion 402a. The height H2 is a distance from the position of the communication port 401d to the uppermost position of the second positioning position 402b. The height H3 is a distance from the position of the communication port 401d to the valve spring seating surfaces 413 and 414. The valve spring seating surfaces 413 and 414 are formed at positions higher than the height H2 of the second positioning portion 402b and lower than the height H1 of the first positioning portion 402a (H2 <H3 <H1). In this case, the opening length L of the opening 403 is substantially equal to or longer than the vertical length of the valve spring (not shown).

  FIGS. 5 and 10 to 13 show the positional relationship between the injector insertion hole 401, the positioning portion 402, and the opening 403. FIG. 10 is a diagram showing a cross section taken along arrow A32 in FIG. 3 from the direction of the arrow. The arrow A32 portion in FIG. 3 corresponds to the height H1 of the first positioning portion 402a in the vertical direction. FIG. 12 is a diagram showing a cross section taken along arrow A33 in FIG. 3 from the direction of the arrow. The arrow A33 portion in FIG. 3 corresponds to slightly above the height H3 of the valve spring seating surfaces 413 and 414 in the vertical direction (Hb within the range from the height H3 to the height H1). 11 is a partially enlarged view of FIG. 10 and FIG. 13 is a partially enlarged view of FIG.

  As shown in FIGS. 10 to 13, an intake valve insertion hole 411 for communicating the stem of the intake valve with the combustion chamber of the cylinder is formed in the bottom wall portion 41 of the space Si on the intake valve side. On the other hand, the bottom wall portion 41 of the space Se on the exhaust valve side is formed with an exhaust valve insertion hole 412 for connecting the stem of the intake valve to the combustion chamber of the cylinder. Further, concentric valve spring seating surfaces 413 and 414 are formed around the intake valve insertion hole 411 and the exhaust valve insertion hole 412 of the bottom wall portion 41, respectively. Stem guides 415 and 416 are assembled to the intake valve insertion hole 411 and the exhaust valve insertion hole 412, respectively.

  In this case, the bottom wall portion 41 of the space Si on the intake valve side subdivided by the first beam portion 43 has an intake valve insertion hole 411 communicating with the combustion chamber of the same cylinder, and a valve spring seating surface therearound. 413 are formed in pairs with the first beam portion 43 interposed therebetween. On the other hand, an exhaust valve insertion hole 412 communicating with the combustion chamber of the same cylinder and a valve spring seating surface 414 therearound are provided in the bottom wall portion 41 of the space Se on the exhaust valve side subdivided by the first beam portion 43. , And are formed in pairs with the first beam portion 43 interposed therebetween. That is, in the combustion chamber of one cylinder, the intake valve and the exhaust valve are respectively arranged in pairs.

  As shown in FIGS. 12 and 13, the opening 403 opens toward the space Si on the intake valve side in the space S surrounded by the outer peripheral wall 42. In the present embodiment, since two intake valves are arranged in one combustion chamber of one cylinder, the opening 403 is located between the intake beams adjacent to each other with the first beam part 43 corresponding to the combustion chamber of one cylinder interposed therebetween. One opening is provided for each of the two spaces Si on the valve side. These openings 403 have the same form (shape, size, arrangement height, etc.). That is, two opening portions 403 are formed in the injector support portion 40 in the directions in which the intake valve insertion holes 411 and the valve spring seating surfaces 413 of the two intake valves communicating with the combustion chamber of the same cylinder are arranged. ing.

  Since the injector support portion 40 has the opening 403, the intake valve insertion hole 411 and the valve spring seating surface 413 can be arranged closer to the injector 9 inserted into the injector insertion hole 401. In the opening 403, since the thickness of the outer peripheral portion of the injector insertion hole 401 is removed, the central axis of the injector 9 (in other words, the central axis of the injector insertion hole 401) is reduced by the removed thickness. The distance from the center axis of the intake valve insertion hole 411 (the inter-axis distance Li shown in FIG. 13) can be reduced. In this case, the center distance Li is shorter (Li <Le) than the distance between the center axis (axis) of the injector 9 and the center axis of the exhaust valve insertion hole 412 (center distance Le shown in FIG. 13).

  Since the intake valve insertion hole 411 and the valve spring seating surface 413 can be brought closer to the injector 9 in this way, the stem and valve spring of the intake valve and the bearing member 43i can also be arranged closer to the injector 9. Thus, the intake system including the cam journal of the camshaft on the intake side supported by the bearing member 43i can be moved toward the center of the injector 9, that is, the cylinder head 4 in the left-right direction (width direction).

  Therefore, the entire width of the cylinder head 4 and thus the entire width of the engine 1 can be reduced, and the size of the engine 1 can be reduced. Further, since the outer peripheral portion of the injector insertion hole 401 is thinned by the opening 403, the weight of the cylinder head 4 and thus the engine 1 can be reduced accordingly.

  The injector insertion hole 401 is formed, for example, by performing a vertical drilling process on a projection (the injector support portion 40 before processing) integrally formed when the cylinder head 4 is formed. At that time, the positioning portion 402 (first to third hole diameter portions 401a to 401c) is formed by gradually increasing the hole diameter of the injector insertion hole 401. After the injector insertion hole 401 is formed, a predetermined position on the outer peripheral portion is cut to form the opening 403. Thus, the injector head 40 having the injector insertion hole 401, the positioning portion 402, and the opening 403 can be provided in the cylinder head 4. The protrusion formed integrally when the cylinder head 4 is formed contains waste made of the riser. Therefore, processing for providing the injector support portion 40 having the injector insertion hole 401, the positioning portion 402, and the opening portion 403 is separately performed on the primary molded product (material) of the cylinder head 4.

  Further, as shown in FIGS. 5 and 9, the outer periphery of the injector 9 inserted into the injector insertion hole 401 is exposed at the opening 403. Therefore, the lubricating oil of the camshaft on the intake valve side may enter the injector insertion hole 401 through the opening 403. For this reason, the gasket 404 is attached to a step between the second hole diameter portion 401b and the third hole diameter portion 401c of the injector insertion hole 401. This prevents camshaft lubricating oil from being mixed into the combustion chamber of the cylinder.

  As described above, the embodiments of the present invention have been described. However, the above-described embodiments have been presented as examples, and are not intended to limit the scope of the invention. Such a novel embodiment can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and their equivalents.

  For example, in the above-described embodiment, the opening portion 403 is formed in the injector support portion 40, but without penetrating the outer peripheral portion of the injector insertion hole 401, without completely removing the meat of the outer peripheral portion, You may form the thin part which left a little. Also in this case, in such a thin portion, the intake valve insertion hole 411 and the valve spring seating surface 413 are brought closer to the injector 9 by the thickness excluding the outer peripheral portion of the injector insertion hole 401, and the axial distance Li is reduced. Can be done.

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Oil pan, 3 ... Cylinder block, 4 ... Cylinder head, 5 ... Rocker cover, 6 ... Front cover, 7 ... Crank pulley, 8 ... Head bolt, 9 ... Injector, 9a ... First of injectors Insertion site, 9b ... second insertion site of injector, 9c ... third insertion site of injector, 40 ... injector support, 41 ... bottom wall, 42 ... outer peripheral wall, 42a ... outer vertical wall, 42b ... Outer lateral wall portion, 43: first beam portion, 43c: cam journal insertion hole, 43e: bearing member, 43i: bearing member, 44: second beam portion, 401: injector insertion hole, 401a: first hole diameter portion , 401b: second hole diameter portion, 401c: third hole diameter portion, 402: positioning portion, 402a: first positioning portion, 402b: second positioning portion, 403: opening portion, 411 Inlet valve insertion hole, 412 ... exhaust valve insertion hole, 413 ... valve spring seating surface, 414 ... valve spring seating surface, H1: height of first positioning portion, H2 ... height of second positioning portion, H3 ... Height of the valve spring seating surface, L: length of the opening, Le: distance between the axis of the injector and the exhaust valve insertion hole, Li: distance of the axis between the injector and the intake valve insertion hole, S: outer peripheral wall , Se: Space on exhaust valve side, Si: Space on intake valve side.

Claims (6)

A bottom wall portion arranged on the cylinder block side of the engine;
An outer peripheral wall standing upright from the periphery of the bottom wall,
An injector support for supporting the injector is provided on the bottom wall,
The injector support portion includes an injector insertion hole into which an injector is inserted, a positioning portion that positions the injector inserted into the injector insertion hole, and an opening that penetrates an outer peripheral portion of the injector insertion hole avoiding the positioning portion. And a cylinder head. The cylinder head according to claim 1, wherein the opening is disposed at a position that does not overlap with the positioning portion with respect to the insertion direction of the injector. A beam portion that is continuous with the injector support portion, partitions a space surrounded by the outer peripheral wall portion into an intake valve side and an exhaust valve side, and subdivides the partitioned intake valve side space and exhaust valve side space, respectively. With
The cylinder head according to claim 1, wherein the opening is open toward a space on the intake valve side. 4. The cylinder head according to claim 3, wherein each of the openings is subdivided by the beam and opens one by one toward a space on the side of the intake valve adjacent thereto. 5. The cylinder head according to any one of claims 1 to 4, wherein the positioning portion is disposed apart from the front side and the back side in the insertion direction of the injector. The positioning portion is a portion of the injector insertion hole, the hole diameter of which is substantially the same as the outer diameter of the injector,
The cylinder head according to claim 5, wherein the hole diameter of the positioning portion on the front side is larger than that of the positioning portion on the rear side.

Images