JP4983568B2 - Cam carrier and manufacturing method thereof - Google Patents

Description

  The present invention relates to a cam carrier constituting a part of a cylinder head of an internal combustion engine and a method for manufacturing the cam carrier.

A cam carrier is known as a part of an internal combustion engine. This cam carrier supports the camshaft and constitutes the upper part of the cylinder head of the internal combustion engine.
Usually, the cam carrier is formed in a so-called ladder shape formed by a pair of vertical frames extending in a direction along the cam shaft and a plurality of horizontal frames spanned between the vertical frames at intervals. For example, see Patent Document 1). The camshaft is supported by bearings formed on several horizontal frames. Also, lubricating oil is supplied to the bearing formed on the horizontal frame.

  Usually, in an internal combustion engine, oil is also supplied to portions other than the bearing of the cam carrier inside the cylinder head. In some cases, a coaxial bearing (specifically, a gap between the inner surface of the bearing and the camshaft) is used as part of an oil passage for use in supplying oil to a portion other than the bearing.

In addition, as a prior art document concerning this invention, the following patent documents 2 other than the said patent document 1 are mentioned.
JP-A-6-299807 JP 2003-193810 A

  By the way, in an internal combustion engine in which a bearing is used as a part of an oil passage, if the roundness of the coaxial bearing is low, the clearance must be increased in order to secure a clearance between the inner surface of the bearing and the camshaft. . As a result, the oil consumption increases and the engine operating efficiency is reduced. Therefore, when the bearing is formed, post-processing such as cutting or polishing is performed as a finishing process. This finishing process requires high processing accuracy.

  Also, as the intake system mechanism of internal combustion engines has become more complex in recent years, the amount of oil consumed in the intake system mechanism has increased, and an oil passage for sending a sufficient amount of oil into the cylinder head has been established. It has become difficult to secure a space for formation.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a cam carrier and a cam carrier capable of easily ensuring both high processing accuracy and a space for forming an oil passage when processing a bearing. It is to provide a manufacturing method.

In the following, means for achieving the above object and its operational effects will be described.
The invention according to claim 1 is formed in a ladder shape including a pair of vertical frames and a plurality of horizontal frames spanning the vertical frames at intervals, and one of the plurality of horizontal frames. A bearing and a base passage for supplying oil to the coaxial bearing are formed, and the bearing is formed in a cam carrier in which the bearing forms part of an oil passage for supplying oil to a portion other than the coaxial bearing. A reinforcing frame integrally connecting the horizontal frame and the adjacent horizontal frame; and the oil passage is formed in a shape extending from the bearing to the adjacent horizontal frame through the interior of the reinforcing frame. This is the gist.

  According to the said structure, the rigidity of the horizontal frame in which the bearing was formed can be made high by providing a reinforcement frame. Therefore, it is possible to suppress bending of the horizontal frame when finishing the bearing formed on the horizontal frame, and it is possible to suppress an unnecessary shift in the relative position between the processing tool and the horizontal frame. As a result, the bearing can be machined with high accuracy during finishing.

  In addition, in a horizontal frame other than the horizontal frame in which the bearing is formed, an oil passage for supplying oil to a portion other than the bearing can be opened. Therefore, the freedom degree about the setting of an oil passage can be raised, and the formation space of the oil passage can be secured easily.

In addition, as a horizontal frame in which the bearing is formed, the outermost one of the plurality of horizontal frames can be adopted as in claim 2.
The invention according to claim 3 is applied to the internal combustion engine in which the cam carrier according to claim 1 or 2 is mounted with an oil pressure actuated change mechanism for changing the valve characteristic of the engine valve, The horizontal frame formed with the bearing is formed with a passage for supplying oil to the changing mechanism and having a shape extending from the bearing to a starting point and opening in the wall surface of the horizontal frame. The gist.

  In the above configuration, a communication path for supplying oil to the change mechanism is formed inside the horizontal frame in which the bearing is formed, and the communication path is opened in the wall surface of the horizontal frame. For this reason, it is difficult to secure a space for forming the entire oil passage and a space for opening the oil passage in the inside and the wall surface of the horizontal frame where the bearing is formed. In this respect, according to the above configuration, it is possible to easily secure a space for forming an oil passage and its opening in such a cam carrier.

  In addition, since high machining accuracy is ensured when finishing the bearing, it is possible to suppress an unnecessary drop in the pressure of oil supplied to the oil pressure actuated change mechanism through the communication path.

  The changing mechanism is provided between the timing chain and the camshaft, and changes the opening timing of the engine valve by changing the relative positions of the timing chain and the camshaft. Things can be adopted.

Moreover, the structure which opens the end of the said oil path in the wall surface of the said adjacent horizontal frame like Claim 5 is employable.
Invention of Claim 6 is a manufacturing method used for manufacture of the cam carrier as described in any one of Claims 1-5, Comprising: The cam carrier by which the pilot hole was formed in the position which corresponds to the said bearing of the said horizontal frame A fixing step of fixing the cam carrier formed with the pilot hole to a support base, and processing by inserting a tool from one end of the pilot hole in the fixed state and machining the bearing. The gist of the present invention is to provide a finishing process for finishing the material.

  In the manufacturing method described above, the horizontal frame may be bent by being pressed by the tool during the finishing process, which causes a decrease in the processing accuracy of the bearing. In this respect, the cam carrier is provided with a reinforcing frame that integrally connects a horizontal frame in which the bearing is formed and a horizontal frame adjacent thereto, and the rigidity of the horizontal frame in which the coaxial receiver is formed is high. Therefore, according to the manufacturing method described above, it is possible to prevent the horizontal frame on which the bearing is formed from being bent during the finishing process, as compared with the case where the cam carrier without the reinforcing frame is manufactured, and the coaxial receiver is highly accurate. Can be processed.

  According to claim 7, the horizontal frame is constituted by a frame main body and a cam cap attached to the frame main body, and the bearing is formed by a groove extending in a semicircular cross section formed in the frame main body and the cam cap, respectively. When manufacturing the constructed cam carrier, it is possible to employ a manufacturing method in which a cam cap is attached to the frame body prior to the finishing step.

Hereinafter, an embodiment embodying a cam carrier and a manufacturing method thereof according to the present invention will be described.
FIG. 1 shows a schematic configuration of an internal combustion engine to which a cam carrier according to the present embodiment is applied, and FIG. 2 shows a structure of the internal combustion engine shown in FIG.

  As shown in FIGS. 1 and 2, a crankshaft 12 is rotatably supported on a cylinder block 11 of the internal combustion engine 10. An oil pan 13 in which oil is stored is attached to the lower part of the cylinder block 11, and an oil pump 13 a for pumping oil to each part of the internal combustion engine 10 is provided inside the oil pan 13. Yes. An intake camshaft 15 and an exhaust camshaft 16 are rotatably supported on the cylinder head 14 of the internal combustion engine 10. A cylinder head cover 17 is attached to the cylinder head 14 so as to cover the upper portion thereof.

  In the internal combustion engine 10, one end of the crankshaft 12 that protrudes outside the cylinder block 11 (the left end in FIG. 1) and one end of each camshaft 15, 16 that protrudes outside the cylinder head 14 (same as above). A timing chain 18 is wound around the left end of FIG. The rotation of the crankshaft 12 is transmitted to the intake camshaft 15 and the exhaust camshaft 16 by the timing chain 18. A chain cover 19 having a shape covering the timing chain 18 is attached to the internal combustion engine 10.

  An intake side changing mechanism 20 is provided between the intake camshaft 15 and the timing chain 18, and an exhaust side changing mechanism 21 is provided between the exhaust camshaft 16 and the timing chain 18. Both the intake side changing mechanism 20 and the exhaust side changing mechanism 21 are of an oil pressure operation type provided for changing the opening timing of the engine valve. Specifically, the intake side changing mechanism 20 is provided for changing the valve opening timing of the intake valve (not shown), and the exhaust side changing mechanism 21 is provided for changing the valve opening timing of the exhaust valve (not shown). .

FIG. 3 shows a schematic configuration of the intake side changing mechanism 20.
As shown in FIG. 3, a housing 32 is formed integrally with a cam sprocket 31 around which the timing chain 18 is wound. The housing 32 is formed in a cylindrical shape, and is provided on the intake camshaft 15 so that the center axis thereof coincides with the rotation axis of the cam sprocket 31. A recess 33 extending in an arc shape in the circumferential direction is formed inside the housing 32. On the other hand, the intake camshaft 15 is integrally formed with a valve body 34 having a shape protruding from the outer peripheral surface thereof. The valve body 34 is disposed inside the housing 32 so as to partition the recess 33 of the housing 32 into two chambers (an advance chamber 35 and a retard chamber 36) in the circumferential direction of the housing 32.

  Then, by supplying oil to one of the advance chamber 35 and the retard chamber 36 and discharging the oil from the other, the valve body in the circumferential direction of the housing 32 as shown by a white arrow in FIG. 34 moves inside the recess 33. As a result, the position of the intake camshaft 15 with respect to the cam sprocket 31 changes, and as a result, the opening timing of the intake valve changes.

  The internal combustion engine 10 is provided with an oil control valve 37. The oil control valve 37 is for switching between an oil supply state and an oil discharge state for each of the advance chamber 35 and the retard chamber 36, and the intake valve is opened by controlling the operation of the oil control valve 37. The timing is controlled.

In addition, since the structure of the exhaust side change mechanism 21 is the same as that of the intake side change mechanism 20, the description about the structure of the exhaust side change mechanism 21 is omitted.
As shown in FIG. 1, the cylinder head 14 includes a head body 22 and a cam carrier 23 in detail. The head body 22 is provided with the intake valve and the exhaust valve, and the cam carrier 23 supports the intake camshaft 15 and the exhaust camshaft 16.

Hereinafter, a specific structure of the cam carrier 23 will be described.
FIG. 4 shows a planar structure of the cam carrier 23.
As shown in FIG. 4, the cam carrier 23 includes a pair of vertical frames 40 extending in a direction along the intake camshaft 15 (see FIGS. 1 and 2) and the exhaust camshaft 16 (left-right direction in FIG. 4) and The ladder frame is formed by N (six in the present embodiment) horizontal frames 41 spanning the vertical frame 40 at intervals.

  (N-1) horizontal frames 41 except for the one farthest from the timing chain 18 (see FIGS. 1 and 2) (the right side in FIG. 4) of the N horizontal frames 41 are frame bodies 44, respectively. And a cam cap 50 attached to the frame main body 44. In the horizontal frames 41, a bearing 42 for the intake camshaft 15 and a bearing 43 for the exhaust camshaft 16 are formed between the frame main body 44 and the cam cap 50. In FIG. 4, only the bearings 42 and 43 formed on the horizontal frame 41 closest to the timing chain 18 (left side in FIG. 4) are denoted by reference numerals.

  FIG. 5 shows an enlarged view of a horizontal frame 41 (hereinafter referred to as a horizontal frame 41A) disposed on the most timing chain 18 side among the N horizontal frames 41 as viewed from the cylinder head cover 17 side. FIG. 6 shows a structure of the cam carrier 23 viewed from the direction of arrow B in FIG.

  As shown in FIGS. 5 and 6, in the horizontal frame 41 </ b> A, a groove 45 (FIG. 6) extending in a semicircular cross section is formed at a position corresponding to the intake camshaft 15 of the frame main body 44. A groove 46 extending in the same shape is formed at a position corresponding to the exhaust camshaft 16.

  A cam cap 50 (hereinafter, referred to as a horizontal frame cam cap 50A) attached to the horizontal frame 41A has a cam cap portion 52 for the intake camshaft 15 and a cam cap portion 53 (the right side portion in FIG. 1) for the exhaust camshaft 16. It is formed. A groove 55 extending in a semicircular cross section is formed in the cam cap portion 52, and a groove 56 having the same shape is also formed in the cam cap portion 53.

  The cam cap 50A is fixed to the frame body 44, whereby the bearing 42 is formed by the groove 45 of the frame body 44 and the groove 55 of the cam cap 50A. The intake camshaft 15 is rotatably supported by the coaxial receiver 42. Further, the cam cap 50A is fixed to the frame body 44, whereby the bearing 43 is formed by the groove 46 of the frame body 44 and the groove 56 of the cam cap 50A. The exhaust camshaft 16 is rotatably supported by the coaxial receiver 43.

  The cam cap 50 is fixed to the frame main body 44 by inserting three bolts respectively inserted into a plurality (three in this embodiment) of the cam cap 50 into the screw holes of the cam carrier 23. This is performed by screwing (not shown). When the cam cap 50 is attached, a metal sliding bearing 47 is disposed between the intake camshaft 15 and the bearing 42, and a similar sliding bearing 48 is disposed between the exhaust camshaft 16 and the bearing 43. Be placed.

  A passage for supplying oil to the intake side changing mechanism 20 and the exhaust side changing mechanism 21 is formed in the cam cap 50A. Below, the specific shape of this channel | path is demonstrated.

  First, a wall 60 having a shape protruding toward the cylinder head cover 17 (see FIG. 6) is integrally formed with the cam cap 50A. The wall portion 60 is formed in a shape extending along the frame main body 44, and an oil distribution passage 61 having a shape extending along the frame main body 44 is formed in the wall portion 60. Further, the cam cap 50A is formed with an oil introduction passage 62 (FIG. 6) having a shape that is open on the surface of the frame main body 44 and extends to the oil distribution passage 61. The oil introduction passage 62 is connected to an oil supply passage 49 on the frame main body 44 side by attaching a cam cap 50A to the frame main body 44, and the oil distribution passage 61 is connected to the oil distribution passage 61 via the oil supply passage 49. Is supplied.

  A connecting portion 71 having a shape protruding toward the cylinder head cover 17 is formed at a position corresponding to the cam cap portion 52 of the cam cap 50A, and the cylinder head cover 17 is formed at a position corresponding to the cam cap portion 53 of the cam cap 50A. A connecting portion 81 having a shape protruding to the side is formed. These connecting portions 71 and 81 are communicated with the oil distribution passage 61.

  In the present embodiment, by attaching the cylinder head cover 17 to the cylinder head 14 (see FIG. 1), the connecting portion 71 is connected to the connecting portion 24 formed in a shape protruding from the lower surface of the cylinder head cover 17 to the cam carrier 23 side. On the other hand, the connection part 81 is connected to the connection part 25 formed in the same shape.

  Thus, the oil control valve 37 (specifically, the oil control valve 37A for the intake side changing mechanism 20) attached to the cylinder head cover 17 and the cam cap portion 52 are communicated with each other via the connection portions 24 and 71. Further, the oil control valve 37 (specifically, the oil control valve 37B for the exhaust side changing mechanism 21) attached to the cylinder head cover 17 and the cam cap portion 53 are communicated with each other via the connection portions 25 and 81.

  Each oil control valve 37A, 37B is a flow path switching valve, and includes one supply port, two pressure adjustment ports, and two discharge ports (both not shown). Each oil control valve 37A, 37B operates such that the supply port is selectively connected to one of the two pressure regulating ports, and the other pressure regulating port is connected to the discharge port.

  As shown in FIG. 5 and FIG. 6, a supply passage 72 communicating with the oil distribution passage 61 is formed in the connecting portion 71, and a supply port of the oil control valve 37 is communicated with the supply passage 72. . On the other hand, two pressure adjusting passages 73 and 74 are formed in the connecting portion 71. One of the discharge ports of the oil control valve 37 is in communication with the pressure adjusting passage 73, and the other is in communication with the pressure adjusting passage 74.

  Further, a supply passage 82 communicating with the oil distribution passage 61 is formed in the connection portion 81, and a supply port of the oil control valve 37B is communicated with the supply passage 82. On the other hand, two pressure adjusting passages 83 and 84 are formed in the connecting portion 81. One of the discharge ports of the oil control valve 37 </ b> B communicates with the pressure regulation passage 83, and the other communicates with the pressure regulation passage 84.

  Therefore, in the present embodiment, the supply passage 72 is selectively communicated with either one of the pressure adjustment passages 73 and 74 through the operation control of the oil control valve 37A, and the supply passage 82 is adjusted through the operation control of the oil control valve 37B. One of the passages 83 and 84 is selectively communicated. In the present embodiment, each pressure adjusting passage 73, 74, 83, 84 functions as a communication passage.

  One end of each of the oil control valves 37 </ b> A and 37 </ b> B is connected to a discharge passage (not shown) opened to the internal space of the cylinder head cover 17. Therefore, the oil in the passage where the supply passage 72 is not communicated between the two pressure regulation passages 73 and 74 is discharged into the cylinder head cover 17 through the discharge passage, and the supply of the two pressure regulation passages 83 and 84 is performed. Oil in the passage where the passage 82 is not communicated is discharged into the cylinder head cover 17 through the discharge passage.

  On the other hand, one end of each of the pressure adjusting passages 73 and 74 is opened inside the bearing 42 of the intake camshaft 15, and the sliding bearing 47 (FIG. 6), the circumferential groove 15a of the intake camshaft 15, and the intake camshaft. 15 is connected to the intake side changing mechanism 20 (specifically, the advance chamber 35 and the retard chamber 36) via pressure regulation passages 15b and 15c. Therefore, through the operation control of the oil control valve 37A, the intake side changing mechanism 20 is driven by supplying the oil to one of the advance chamber 35 and the retard chamber 36 and discharging the oil from the other, whereby the intake valve changing mechanism 20 is driven. The valve opening time is changed.

  Further, one end of each of the pressure adjusting passages 83 and 84 is opened inside the bearing 43 of the exhaust camshaft 16, and the pressure adjustment in the slide bearing 48, the circumferential groove 16a of the exhaust camshaft 16, and the exhaust camshaft 16 is performed. The exhaust side change mechanism 21 is connected to the advance chamber and the retard chamber through the passages 16b and 16c. Therefore, through the operation control of the oil control valve 37B, the exhaust side change mechanism 21 is driven by supplying oil to one of the advance chamber and the retard chamber of the exhaust side change mechanism 21 and discharging the oil from the other. As a result, the opening timing of the exhaust valve is changed.

7 shows a cross-sectional structure of the cam carrier 23 taken along line CC in FIG. 4, and FIG. 8 shows a cross-sectional structure of the cam carrier 23 taken along line DD in FIG.
As shown in FIGS. 7 and 8, a base passage 63 for supplying oil to the bearings 42 and 43 is formed in the lateral frame 41 </ b> A of the cam carrier 23. The base passage 63 includes a supply path 64 extending from the lower surface of the frame main body 44 to the bearing 42, a supply groove 65 communicating with the supply path 64 and formed on the inner surface of the bearing 42, the supply groove 65, and the A supply path 66 that communicates with the bearing 43 is formed. An oil introduction passage (not shown) on the head body 22 side is communicated with the base passage 63 by attaching the cam carrier 23 to the head body 22, and oil is supplied through the oil introduction passage. Yes. Thus, in the present embodiment, oil is supplied to the bearings 42 and 43 through the base passage 63.

  In addition to the vertical frame 40 and the horizontal frame 41, the cam carrier 23 is provided with a reinforcing frame 67 (FIG. 8). The reinforcing frame 67 is spanned between the horizontal frame 41A and the adjacent horizontal frame 41 (hereinafter referred to as “horizontal frame 41B”), and is formed in a shape that integrally connects the horizontal frames 41A and 41B. (See FIG. 4).

  Here, the cylinder head cover 17 (see FIG. 1) has a shower pipe (not shown) for spraying oil inside the cylinder head 14 in order to supply oil to the intake system mechanism inside the cylinder head 14. It is attached. As shown in FIGS. 7 and 8, the cam carrier 23 of the present embodiment is provided with an oil passage 68 for supplying oil to the shower pipe. The oil passage 68 is formed in a shape extending from the bearing 42 (specifically, the supply passage 66) to the starting point (FIG. 7), through the inside of the reinforcing frame 67 (FIG. 8), and to the horizontal frame 41B. The oil passage 68 opens on the surface of the horizontal frame 41B on the cylinder head 14 side (specifically, the surface of the cam cap 50 (cam cap 50B) attached to the horizontal frame 41B on the cylinder head 14 side). Yes. In the present embodiment, by attaching the cylinder head cover 17 (see FIG. 1) to the cylinder head 14, the opening portion of the oil passage 68 in the horizontal frame 41B (FIG. 8) is connected to one end of the shower pipe. It has become.

Hereinafter, a method for manufacturing the cam carrier 23 will be described.
In the present embodiment, the cam carrier 23 is manufactured through the “forming process”, “attaching process”, “fixing process”, and “finishing process”. Hereinafter, each of these steps will be described in detail.

"Formation process"
When the cam carrier 23 is manufactured, first, in the forming process, the cam carrier 23 in which pilot holes are formed at positions corresponding to the bearings 42 and 43 of the lateral frame 41A is formed. Specifically, the cam carrier 23 in which grooves extending in a semicircular cross section are formed at positions corresponding to the bearings 42 and 43 of the frame main body 44 corresponding to the horizontal frame 41A, and a semicircular cross section at positions corresponding to the bearings 42 and 43. A cam cap 50A having a groove extending in a shape is formed. The cam carrier 23 and the cam cap 50A are formed by finishing a cast metal such as an aluminum alloy by grinding.

"Installation process"
Next, in the attaching step, the cam cap 50A is attached to the frame main body 44 corresponding to the horizontal frame 41A.

"Fixing process"
In the subsequent fixing step, as shown in FIG. 9, the cam carrier 23 is fixed to the support base 91 of the processing apparatus.

"Finishing process"
Then, in the finishing process, as shown by the white arrow in FIG. 10, the rotary tool 92 is inserted into the prepared hole formed at the position corresponding to the bearing 42 of the cam carrier 23 from one end thereof, and the same operation is performed from the prepared hole. The rotary tool 92 is escaped. As a result, the inner surface of the pilot hole is processed to form a bearing 42 on the cam carrier 23. Similarly, the rotary tool 92 is inserted from one end into a pilot hole formed at a position corresponding to the bearing 43 of the cam carrier 23 and the rotary tool 92 is withdrawn from the pilot hole. Is processed to form a bearing 43 on the cam carrier 23.

Hereinafter, the effect | action by providing the said cam carrier 23 is demonstrated.
When manufacturing the cam carrier 23 described above, the horizontal frame 41A may be bent by being pressed by the rotary tool 92 in the “finishing step”, which causes a decrease in the processing accuracy of the bearing 42. .

  In the present embodiment, a reinforcing frame 67 is provided on the cam carrier 23. Therefore, the cam carrier 23 has higher rigidity of the lateral frame 41A than the cam carrier in which the reinforcing frame 67 is not provided. Therefore, although the horizontal frame 41A is pressed by the rotary tool 92 in the “finishing step”, the horizontal frame 41A is prevented from being bent by the pressing force, and the rotary tool 92 and the horizontal frame 41A are prevented from being bent. Unnecessary deviation of the relative position can be suppressed small. As a result, the bearings 42 and 43 can be machined with high accuracy in the “finishing step”.

  In the internal combustion engine 10, when the gap between the inner surface of the bearing 42 and the intake camshaft 15 becomes large, the amount of oil leaking from the gap increases accordingly, so that the supply to the intake side change mechanism 20 and the exhaust side change mechanism 21 is performed. The pressure of the oil is reduced, and the amount of oil supplied to the shower pipe is reduced. Therefore, when the machining accuracy of each of the bearings 42 and 43 is low, in order to sufficiently secure the pressure of oil supplied to the intake side change mechanism 20 and the exhaust side change mechanism 21 and the amount of oil supplied to the shower pipe, the machining error It is necessary to supply extra oil in anticipation of the pressure drop due to. This causes various inconveniences such as an increase in the size of the oil pump 13a due to an unnecessary increase in oil consumption and a decrease in operating efficiency of the internal combustion engine 10. In the present embodiment, since the bearings 42 and 43 can be machined with high accuracy, the occurrence of such inconvenience can be suppressed.

  In the present embodiment, the oil passage 68 for supplying oil to the shower pipe is formed in a shape extending from the bearing 42 to the horizontal frame 41B through the inside of the reinforcing frame 67. Therefore, by using the reinforcing frame 67, the oil passage 68 can be extended to the horizontal frame 41B adjacent to the horizontal frame 41A on which the bearing 42 is formed and can be opened on the wall surface of the horizontal frame 41B. . Therefore, the degree of freedom for setting the oil passage 68 can be increased, and a space for forming the oil passage 68 and its opening can be easily secured.

  Here, the intake side changing mechanism 20 and the exhaust side changing mechanism 21 are mounted on the internal combustion engine 10 of the present embodiment. A passage (oil distribution passage 61, oil introduction passage 62, supply passages 72, 82) for supplying oil to the intake side change mechanism 20 and the exhaust side change mechanism 21 is provided inside the horizontal frame 41A of the cam carrier 23. And pressure regulating passages 73, 74, 83, 84) are formed. Further, the pressure adjusting passages 73, 74, 83, 84 and the supply on the wall surface of the horizontal frame 41A (specifically, the surface of the cam cap 50A on the cylinder head cover 17 side and the inner surfaces of the grooves 45, 46 of the frame main body 44). The passages 72 and 82 are opened. Therefore, in the cam carrier 23, a space for forming the entire oil passage for supplying oil to the shower pipe is secured inside the horizontal frame 41A, and a space for opening the oil passage is provided. It is difficult to ensure on the wall surface of the horizontal frame 41A. In the present embodiment, in such a cam carrier 23, a space for forming the oil passage 68 and its opening can be easily secured.

As described above, according to the present embodiment, the effects described below can be obtained.
(1) Since the reinforcing frame 67 that integrally connects the horizontal frames 41A and 41B is provided, the bearings 42 and 43 are processed with high accuracy when finishing the bearings 42 and 43 formed on the horizontal frame 41A. be able to. Moreover, since the oil passage 68 is formed in a shape extending from the bearing 42 of the lateral frame 41A to the lateral frame 41B through the inside of the reinforcing frame 67, the degree of freedom in setting the oil passage 68 can be increased. A space for forming the passage 68 can be easily secured.

  (2) In the cam carrier 23 in which it is difficult to secure a space for forming the entire oil passage 68 or a space for opening the oil passage 68 inside or on the wall surface of the horizontal frame 41A, the oil passage 68 and its opening A space for forming the film can be easily secured. Moreover, in order to ensure high machining accuracy when finishing the bearings 42 and 43, the pressure of the oil supplied to the intake side changing mechanism 20 and the exhaust side changing mechanism 21 through the pressure adjusting passages 73, 74, 83, and 84. Can be suppressed.

The embodiment described above may be modified as follows.
The passage through which the oil passage 68 is communicated is not limited to a shower pipe, and a passage for supplying oil to a portion other than the bearing 42 (for example, an intake system mechanism such as a lash adjuster) can be employed.

The opening position of the oil passage 68 is not limited to the wall surface of the horizontal frame 41B as long as it is a part other than the wall surface of the horizontal frame 41A, and can be arbitrarily changed, for example, the wall surface of the vertical frame 40.
・ As a reinforcing frame with oil passages for supplying oil to parts other than bearings, it has a shape that integrally connects the horizontal frame arranged closest to the timing chain and the adjacent horizontal frame. However, the shape may be such that two horizontal frames other than the horizontal frames are integrally connected. In short, the reinforcing frame may be formed in a shape that integrally connects a horizontal frame in which a bearing serving as a starting point of the oil passage is formed and a horizontal frame adjacent thereto.

  The present invention is not limited to an internal combustion engine in which a timing chain is wound between a crankshaft and a camshaft, and is also applied to an internal combustion engine in which a timing belt is wound between a crankshaft and a camshaft. Can do.

  The present invention is also applicable to an internal combustion engine that is not provided with an intake side change mechanism or an exhaust side change mechanism.

1 is a schematic configuration diagram of an internal combustion engine to which an embodiment embodying the present invention is applied. The side view which shows the structure which looked at the internal combustion engine shown in FIG. 1 from the arrow A direction. The schematic block diagram of the intake side change mechanism provided in the internal combustion engine. The top view of the cam carrier provided in the internal combustion engine. The top view which shows the structure which looked at the horizontal frame arrange | positioned most at the timing chain side from the cylinder head cover side. The side view which shows the structure which looked at the cam carrier from the arrow B direction of FIG. Sectional drawing which shows the cross-sectional structure along CC line in FIG. 4 of a cam carrier. Sectional drawing which shows the cross-sectional structure along the DD line | wire in FIG. 4 of a cam carrier. Process drawing which shows one of the processes concerning manufacture of a cam carrier. Process drawing which shows one of the processes concerning manufacture of a cam carrier.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Cylinder block, 12 ... Crankshaft, 13 ... Oil pan, 14 ... Cylinder head, 15 ... Intake camshaft, 15a ... Circumferential groove, 15b, 16b ... Pressure regulation path, 16 ... Exhaust camshaft, 16a ... Circumferential groove, 16b, 17b ... Pressure adjusting passage, 17 ... Cylinder head cover, 18 ... Timing chain, 19 ... Chain cover, 20 ... Intake side change mechanism, 21 ... Exhaust side change mechanism, 22 ... Head body, 23 ... Cam Carrier, 24, 25 ... connecting portion, 31 ... cam sprocket, 32 ... housing, 33 ... groove, 34 ... valve body, 35 ... advance chamber, 36 ... retard chamber, 37, 37A, 37B ... oil control valve, 40 ... vertical frame, 41, 41A, 41B ... horizontal frame, 42, 43 ... bearing, 44 ... frame body, 45, 46 ... groove, 47, 4 ... Slide bearing, 49 ... oil supply passage, 50, 50A, 50B ... cam cap, 52, 53 ... cam cap portion, 55,56 ... groove, 57 ... insertion hole, 60 ... wall portion, 61 ... oil distribution passage, 62 ... oil introduction passage, 63 ... base passage, 64, 66 ... supply passage, 65 ... supply groove, 67 ... reinforcing frame, 68 ... oil passage, 71, 81 ... connection, 72, 82 ... supply passage, 73, 74, 83, 84 ... pressure adjusting passage, 91 ... support base, 92 ... rotating tool.

Claims (7)

It is formed in a ladder shape composed of a pair of vertical frames and a plurality of horizontal frames spanning the vertical frames at intervals, and oil is applied to a bearing and a coaxial receiver in one of the plurality of horizontal frames. In a cam carrier that is formed with a base passage to be supplied and the bearing forms a part of an oil passage for supplying oil to a portion other than the coaxial receiver,
A reinforcing frame that integrally connects the horizontal frame in which the bearing is formed and the horizontal frame adjacent thereto;
The oil carrier is formed in a shape extending from the bearing to the adjacent lateral frame through the inside of the reinforcing frame. Oite the Kamukyari A according to claim 1,
The cam carrier according to claim 1, wherein the horizontal frame on which the bearing is formed is located on the outermost side among the plurality of horizontal frames. It is applied to an internal combustion engine equipped with an oil pressure actuated change mechanism that changes the valve characteristics of the engine valve,
A passage for supplying oil to the change mechanism and having a shape that extends from the bearing to a starting point and opens in a wall surface of the transverse frame is formed in the transverse frame in which the bearing is formed. The cam carrier according to 1 or 2. The cam carrier according to claim 3,
The change mechanism is provided between the timing chain and the camshaft, and changes the valve opening timing of the engine valve by changing the relative positions of the timing chain and the camshaft. . The cam carrier according to any one of claims 1 to 4,
The oil carrier is formed in a shape that opens in a wall surface of the adjacent horizontal frame. It is a manufacturing method used for manufacture of the cam carrier according to any one of claims 1 to 5,
Forming a cam carrier having a pilot hole formed at a position corresponding to the bearing of the horizontal frame;
A fixing step of fixing the cam carrier in which the pilot hole is formed to a support base;
And a finishing step of finishing the bearing by inserting a tool into the prepared hole from one end and machining the pilot hole in a fixed state. In the manufacturing method of the cam carrier according to claim 6,
A cam carrier in which the horizontal frame is constituted by a frame main body and a cam cap attached to the frame main body, and the bearing is constituted by a groove extending in a semicircular cross section formed in the frame main body and the cam cap, respectively. Applied,
Prior to the finishing step, the method further comprises an attaching step of attaching the cam cap to the frame body.

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