JPWO2006132255A1 - Camshaft assembly method for internal combustion engine and internal combustion engine - Google Patents

Abstract

In a camshaft assembling method for an internal combustion engine in which a camshaft is assembled to a cylinder head via a plurality of independent cam carriers and cam caps for each journal portion, the journal portion has a length straddling the plurality of cam carriers. A shaft-shaped jig having a shaft diameter of the fitting portion corresponding to the diameter of the journal portion is larger than that of the journal, and the shaft-shaped jig is attached to the cylinder head via the plurality of sets of cam carriers. A camshaft assembling method for an internal combustion engine in which the plurality of cam carriers are positioned at predetermined positions.

Description

  The present invention relates to a method of assembling a camshaft of an internal combustion engine and an internal combustion engine in which the camshaft is assembled by this method.

Conventionally, as this kind of thing, there exists a thing as described in patent document 1, for example. This Patent Document 1 includes a lower cam holder (cam carrier) arranged in common on both intake and exhaust camshafts, and an upper cam holder (cam cap) provided on each of the intake and exhaust camshafts. And both ends of the lower cam holder are fastened to the cylinder head by a first fastening member, and the two upper cam holders are fastened to the lower cam holder by a pair of second fastening members having a smaller diameter than the first fastening member. It is described that the cylinder heads can be reduced in size, and the first fastening member also serves as a detent for the rocker shaft.
JP 2000-170506 A.

  However, in such a conventional one, a clearance is provided between the journal portion of the camshaft and the bearing portion of the cam carrier and the cam cap into which the journal portion is inserted. When the camshaft is attached to the cylinder head via a plurality of cam carriers and cam caps with bearings formed in advance, the cam head is attached to the cylinder head. As a result, the position accuracy is deteriorated, and as a result, there is a possibility that the hitting of the journal part and the friction of the journal part increase.

  As a countermeasure, to secure the assembly position accuracy of the cam carrier, etc., if a plurality of cam carriers and cam caps are attached to the cylinder head and threaded, then the camshaft is attached. Processing equipment becomes large-scale.

  Further, when a plurality of cam carriers and cam caps are machined in this way, even if a problem occurs in one cam carrier (or cam cap), a plurality of cam carriers and cams corresponding to one camshaft. It is necessary to replace all caps, and there are many replacement parts, resulting in high costs.

  Therefore, the present invention can ensure the positional accuracy of the supporting portion of the journal portion without using the large-scale processing equipment necessary to avoid the deterioration of the hitting of the journal portion and the increase of the friction of the journal portion. An object of the present invention is to provide a camshaft assembling method for an internal combustion engine and an internal combustion engine that can minimize replacement parts even when a malfunction occurs in a cam carrier or the like.

  In order to achieve this object, the invention according to claim 1 is the camshaft assembly for an internal combustion engine in which the camshaft is assembled to the cylinder head via a plurality of cam carriers and cam caps independent for each journal portion. In the method, a shaft-shaped jig having a length extending over the plurality of cam carriers and having a shaft diameter of a fitting portion at a portion corresponding to the journal portion larger than that of the journal portion is prepared. An internal combustion engine camshaft assembling method is provided in which a tool is attached to the cylinder head via the plurality of sets of cam carriers, and the plurality of cam carriers are positioned at predetermined positions.

  According to a second aspect of the present invention, in the camshaft assembling method for an internal combustion engine, the camshaft is actually assembled to the cylinder head through a plurality of cam carriers and cam caps independent for each journal portion. A shaft-shaped jig is prepared in which the shaft diameter of the fitting portion corresponding to the journal portion of the shaft is larger than the shaft diameter of the journal portion, and the shaft-shaped jig is attached to the plurality of sets of cam carriers and cam caps. The plurality of cam carriers are attached to the cylinder head via a predetermined position, and then the plurality of cam carriers are removed from the plurality of cam caps while the cam carriers remain fastened to the cylinder head. Internal combustion in which a shaft-shaped jig is rearranged to the camshaft that is actually used, and then the plurality of cam caps are fastened Characterized in that the cam shaft assembly method for Seki.

  According to a third aspect of the present invention, in the camshaft assembling method for an internal combustion engine, the camshaft is actually assembled to the cylinder head via a plurality of cam carriers and cam caps that are independent for each journal portion. A shaft-shaped jig is prepared in which the shaft diameter of the fitting portion corresponding to the journal portion of the shaft is larger than the shaft diameter of the journal portion, and the shaft-shaped jig is connected to the cylinder via the plurality of cam carriers. The camshaft is mounted on a head to position the plurality of cam carriers at a predetermined position, and then the shaft-shaped jig is actually used while the plurality of cam carriers are still fastened to the cylinder head. And a camshaft assembling method for an internal combustion engine in which the plurality of cam caps are fastened.

  According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects, a positioning portion is formed in the shaft-shaped jig, and the positioning of the cam carrier allows Positioning in the shaft-shaped jig axis direction is performed.

  According to a fifth aspect of the present invention, in addition to the configuration according to any one of the first to fourth aspects, the shaft-shaped jig includes a cam portion at a position corresponding to the cam portion of the camshaft. A circular portion having the same diameter as that of the base circle is formed.

  The invention according to claim 6 is the camshaft assembling method for an internal combustion engine in which the camshaft is assembled to the cylinder head via a plurality of cam carriers and cam caps independent for each journal portion. The camshaft also serves as a shaft-shaped jig for positioning the cam carrier, and the camshaft is provided with a journal portion held by the bearing portion of the cam carrier and the cam cap and is thicker than the journal portion adjacent to the journal portion. A fitting portion is provided, and the cam carrier and the cam cap are provided with a fitted portion to which the fitting portion is fitted adjacent to the bearing portion, and the journal portion outer surface and the bearing portion inner surface. The clearance between the outer surface of the fitting portion and the inner surface of the fitted portion is smaller than the clearance with the camshaft fitting Is fitted to the cam carrier and the cam cap fitted portion, the camshaft is attached to the cylinder head via the cam carrier and the cam cap, and then the camshaft is slid in a predetermined amount in the axial direction. Then, the camshaft assembling method for an internal combustion engine is configured such that sliding of the camshaft is regulated by attaching the slide regulating member in this state by detaching the fitting portion from the fitted portion. It is characterized by.

  According to a seventh aspect of the present invention, in addition to the configuration of the sixth aspect, the fitted portion also serves as a part of the bearing portion, and the outer diameter of the fitted portion is the outer diameter of the journal portion. It is characterized by being larger.

  According to an eighth aspect of the invention, in addition to the configuration of the sixth aspect, the outer diameter of the fitting portion is larger than the outer diameter of the journal portion, and the inner diameter of the fitted portion is that of the bearing portion. It is characterized by being larger than the inner diameter.

  According to a ninth aspect of the present invention, in addition to the configuration of the sixth aspect, the slide restricting member is a housing cap provided at an end of the camshaft.

  According to a tenth aspect of the present invention, in addition to the configuration according to any one of the first to ninth aspects, a plurality of the cam carriers are arranged along the cam shaft, and the cam carriers are independent of each other. The rocker shaft is disposed, and the rocker arm is swingably disposed on the rocker shaft.

  According to an eleventh aspect of the present invention, in the camshaft assembling method for an internal combustion engine according to any one of the first to tenth aspects, the camshaft is connected to the cylinder head via the cam carrier and the cam cap. It is an assembled internal combustion engine.

  According to the first aspect of the present invention, the shaft-shaped jig has a length straddling a plurality of cam carriers, and the shaft diameter of the fitting portion of the portion corresponding to the journal portion is larger than the shaft diameter of the journal portion. The shaft-shaped jig is attached to the cylinder head via the plural sets of cam carriers, and the camshaft assembling method for the internal combustion engine in which the plural cam carriers are positioned at predetermined positions. Even without using large-scale processing equipment that was necessary to avoid the deterioration of the contact of the part and the increase of the friction of the journal part, the position accuracy of the support part of the journal part can be ensured, and there is a problem with the cam carrier etc. Even if it occurs, replacement parts can be minimized.

  According to the second aspect of the present invention, a shaft-shaped jig is prepared in which the shaft diameter of the portion corresponding to the journal portion of the cam shaft to be actually assembled is thicker than the shaft diameter of the journal portion. Attach to the cylinder head via the cam carrier and the cam cap, and then remove the cam cap while the cam carrier is still fastened to the cylinder head, and reassemble the shaft-shaped jig to a camshaft that is actually used. Later, the camshaft assembling method for fastening the cam cap was adopted, so that there was no need to use the large-scale processing equipment that was necessary to avoid the deterioration of the hitting of the journal part and the increase in friction of the journal part. Therefore, the position accuracy of the support part of the journal can be ensured, and even if a cam carrier malfunctions, the replacement part should be It can be suppressed to the limit.

  According to the third aspect of the present invention, it is not necessary to attach or detach the cam cap when the shaft-shaped jig is disposed (centering), so that workability is good.

  According to the invention described in claim 4, since the positioning portion is formed in the shaft-shaped jig, and the cam carrier is positioned in the shaft-shaped jig axial direction by this positioning portion, the shaft-shaped jig is arranged. The tool can reduce the width of the cam part and the journal part by reducing the center of the cam carrier and improving the positional accuracy in the axial direction, thereby reducing the weight.

  According to the fifth aspect of the present invention, the shaft-shaped jig has a circular portion having the same diameter as the diameter of the base circle of the cam portion at a position corresponding to the cam portion of the camshaft. With the circular portion, the clearance adjustment between the rocker arm disposed on the cam carrier and the base circle portion of the cam portion can be performed without rotating the cam shaft.

  According to the sixth to ninth aspects of the present invention, since the camshaft also serves as a shaft-shaped jig for positioning the cam carrier, it is not necessary to use a separate shaft-shaped jig. The effect similar to that of claim 1 can be obtained, and workability and the like can be improved.

  According to the tenth aspect of the present invention, since the rocker shaft is independently provided for each cam carrier, when the rocker shaft is provided, it is not necessary to perform threading, and the large scale There is no need to use processing equipment.

  According to the eleventh aspect of the present invention, the camshaft is assembled to the cylinder head via the cam carrier and the cam cap by the camshaft assembling method for the internal combustion engine according to any one of the first to tenth aspects. Since the internal combustion engine is used, the position accuracy of the support portion of the journal portion can be ensured, and even when a problem occurs in the cam carrier or the like, replacement parts can be minimized.

It is sectional drawing which shows the shaft-shaped jig | tool, cam carrier, cam cap, etc. which concern on Embodiment 1 of this invention. FIG. 3 is an exploded perspective view showing a cylinder head, a camshaft, a cam carrier, a cam cap and the like according to the first embodiment. It is sectional drawing which shows the shaft-shaped jig | tool, cam carrier, cam cap, etc. which concern on Embodiment 2 of this invention. FIG. 4 is an enlarged view showing a part of FIG. 3 according to the second embodiment. It is sectional drawing which shows the circular part of the shaft-shaped jig | tool which concerns on the same Embodiment 2. FIG. It is sectional drawing which shows the camshaft, cam carrier, cam cap, etc. which concern on Embodiment 3 of this invention, (a) shows the state in the middle of attachment of a camshaft, (b) shows the attachment completion state of a camshaft. . FIGS. 7A and 7B are enlarged views showing a part of FIG. 6 according to the third embodiment, in which FIG. 6A shows a state in the middle of mounting of the camshaft, and FIG. It is explanatory drawing which shows the effect | action which concerns on the same Embodiment 3, (a) shows the state in the middle of attachment of a cam shaft, (b) shows the completion state of attachment of a cam shaft. It is sectional drawing which shows the cam shaft, cam carrier, cam cap, etc. which concern on Embodiment 4 of this invention, (a) shows the state in the middle of attachment of a cam shaft, (b) shows the completion state of attachment of a cam shaft. . FIGS. 9A and 9B are enlarged views showing a part of FIG. 9 according to the fourth embodiment, where FIG. 9A shows a state in the middle of attachment of the camshaft, and FIG.

Embodiments of the present invention will be described below.
Embodiment 1 of the Invention

  1 and 2 show a first embodiment of the present invention.

  First, the configuration will be described. Reference numeral 11 in FIG. 2 denotes an engine as an “internal combustion engine”. The engine 11 includes a plurality of cam carriers each having an intake camshaft 13 and an exhaust camshaft 14 on a cylinder head 12. 17, a cam cap 18, and a set of cam carrier 21 and cam cap 22, which are rotatably supported.

  Each of the intake camshaft 13 and the exhaust camshaft 14 is formed with a plurality of intake cam portions 13a and exhaust cam portions 14a, and between adjacent intake cam portions 13a and adjacent exhaust. Journal portions 13b and 14b are respectively formed between the cam portions 14a. Each camshaft 13, 14 has one end portion 13 c, 14 c as a power transmission portion, is formed to have a larger diameter than the other portion, and is rotatably held by cam carrier 21 and cam cap 22. The flange portions 13d and 13e and the flange portions 14d and 14e for receiving the thrust are formed on both sides of the end portions 13c and 14c, respectively. Furthermore, VVT cam sensor rotors 13g and 14g are provided at the other end.

  Furthermore, each cam carrier 17 is formed with a bearing recess 17a that forms the lower half of the bearing portions 15 and 16 of the journal portions 13b and 14b of the cam shafts 13 and 14, respectively.

  Furthermore, a rocker shaft 24 is independently provided for each cam carrier 17, and a rocker arm 25 is swingably supported on the rocker shaft 24. In addition, each cam carrier 17 is formed with a bolt hole 17c through which a bolt 26 for attachment to the cylinder head 12 is inserted, and a bolt 27 for attaching the cam cap 18 and the cam carrier 17 to the cylinder head 12. A bolt hole 17d through which is inserted is formed.

  The cam cap 18 has a bearing recess 18a that forms the upper half of the bearings 15 and 16, and a bolt hole 18b through which the bolt 27 is inserted.

  Further, the cam carrier 21 and the cam cap 22 are also formed with bearing recesses 21a and 22a for supporting the cam shafts 13 and 14, respectively.

  Further, a plurality of knock pins 12 a that are fitted to the cam carrier 21 at one end and the cam carrier 17 at the other end are provided on the upper surface portion of the cylinder head 12.

  A shaft-shaped jig 30 as shown in FIG. 1 is used to assemble the camshafts 13 and 14 and the like.

  In the shaft-shaped jig 30, the shaft diameter d1 of the fitting portion 30a corresponding to the journal portions 13b and 14b of the camshafts 13 and 14 to be actually assembled is thicker by a predetermined amount than the shaft diameter of the journal portions 13b and 14b. Is formed. This predetermined amount is an amount for ensuring the necessary amount of clearance between the outer surfaces of the journal portions 13b and 14b of the camshafts 13 and 14 and the inner surfaces of the bearing portions 15 and 16 in consideration of variations of the respective portions. Is set to

  Further, a pair of flange portions 30b are formed at the right end portion of the shaft-shaped jig 30 in FIG. 1, and a cam cap 22 is fitted between the pair of flange portions 30b to restrict movement in the thrust direction. It has come to be.

  Next, the case where the camshafts 13 and 14 are assembled using the shaft-shaped jig 30 will be described.

  The cam carrier 21 at one end and the cam carrier 17 at the other end are positioned by a knock pin 12 a, a bolt 26 is inserted into a so-called bolt hole 17 c of the cam carriers 21, 17, and the bolt 26 is loosely fixed to the cylinder head 12.

  Next, a bolt 26 is inserted into a so-called flawed bolt hole 17c of the cam carrier 17 between the cam carrier 21 at one end and the cam carrier 17 at the other end, so that the plurality of cam carriers 17 move slightly. Is loosely screwed into the cylinder head 12.

  Next, the two shaft-shaped jigs 30 are placed on the bearing recesses 17a and 21a on the intake side and the exhaust side of the cam carriers 17 and 21, respectively, and the cam cap 22 and the cam cap 18 are covered from above. Tighten with bolts 26 and 27. Incidentally, if the bearing recesses on the intake side and the exhaust side are formed in separate cam carriers, a single shaft-shaped jig may be mounted.

  In this state, it is confirmed that the shaft-like jig 30 rotates smoothly by hand or jig.

  Next, the bolt 27 is loosened, the cam caps 18 and 22 are removed, the shaft-shaped jig 30 is removed, the camshafts 13 and 14 are replaced, and the cam caps 18 and 22 are mounted again.

  When the shaft-like jig 30 is used as described above, when the cam-like jigs 30 and 14 are incorporated between the outer surface of the fitting portion 30a of the shaft-like jig 30 and the inner surfaces of the bearing portions 13 and 14, respectively. Therefore, unlike the conventional case, the cam carrier 17 and the cam cap 18 can be attached to the shaft-shaped jig 30 with small backlash.

  Therefore, in this state, the plurality of cam carriers 17 can be attached to the cylinder head 12 with high accuracy by performing the final tightening of the cam carrier 17 and the like.

  As a result, it is possible to avoid deterioration of the contact of the journal portions 13b and 14b of the camshafts 13 and 14 and an increase in friction of the journal portions 13b and 14b.

  Therefore, it is possible to ensure the positional accuracy of the support portions of the journal portions 13b and 14b without using a large-scale processing facility.

  Further, even if a problem occurs in the cam carrier 17 or the like, it is not necessary to perform through machining as in the prior art. It can be assembled using the tool 30, and replacement parts can be minimized.

  Further, since the rocker shaft 24 is independently arranged on the plurality of cam carriers 17, after the plurality of cam carriers 17 are attached to the cylinder head 12, a threading process for improving the positional accuracy of the rocker shaft 24 is performed. There is no need to do it.

  The cam cap 18 is fastened to the cylinder head 12 here, but is not limited thereto, and may be fastened to the cam carrier 17.

  In the first embodiment, when the shaft-like jig 30 is disposed, the cam cap 18 is also attached. However, the present invention is not limited to this, and only the cam carrier 17 is attached to the cylinder head 12 with the bolts 26. Thus, centering can be performed by the shaft-shaped jig 30.

  In this case, at the time of the centering, the cam carrier 17 is centered by the shaft-shaped jig 30 without attaching the cam cap 18, and then the shaft-shaped jig 30 is removed to remove the camshaft 13. 14 and then the cam cap 18 is attached.

  In this way, since it is not necessary to attach and detach the cam cap 18 when the shaft-shaped jig 30 is disposed (centering), workability is good.

Here, the knock pin 12a is fitted to both the cam carriers 21 and 17 at both ends. However, the present invention is not limited to this, and the knock pin 12a is fitted only to the cam carrier 21 or 17 on one side. On the other hand, there is a case where it is not necessary to fit a knock pin.
[Embodiment 2 of the Invention]

  3 to 5 show a second embodiment of the present invention.

  The second embodiment is different from the first embodiment in that the shaft-shaped jig 40 is provided with a positioning portion 40a and a circular portion 40b.

  That is, in the shaft-shaped jig 40, the shaft diameter d of the fitting portion 40c corresponding to the journal portions 13b and 14b of the camshafts 13 and 14 to be actually assembled is larger than the shaft diameter of the journal portions 13b and 14b by a predetermined amount. Is formed. This predetermined amount is an amount for ensuring the necessary amount of clearance between the outer surfaces of the journal portions 13b and 14b of the camshafts 13 and 14 and the inner surfaces of the bearing portions 15 and 16 in consideration of variations of the respective portions. Is set to

  Then, a stepped positioning portion 40a is formed adjacent to the fitting portion 40c, and the positioning portion 40a is engaged with the engaging portions 17e and 18c of the cam carrier 17 and the cam cap 18. Yes.

  Further, the circular portion 40b of the shaft-shaped jig 40 is formed at a position corresponding to the cam portions 13a and 14a of the cam shafts 13 and 14, and is formed to have the same diameter as the base circle of the cam portions 13a and 14a. ing.

  Further, a pair of flanges 40d for receiving thrust is also formed at the end of the shaft-shaped jig 40.

  In such a case, the shaft-shaped jig 40 is formed with the positioning portion 40a, and the positioning portion 40a is used to position the cam carrier 17 in the axial direction of the shaft-shaped jig 40. The shaft-shaped jig 40 can reduce the width of the cam portion and the journal portion by centering the cam carrier 17 and improving the positional accuracy in the axial direction, thereby reducing the weight.

  The shaft-shaped jig 40 has a circular portion 40b having the same diameter as the base circle of the cam portions 13a and 14a at positions corresponding to the cam portions 13a and 14a of the cam shafts 13 and 14. The clearance between the rocker arm 25 disposed on the cam carrier 17 and the base circle of the cam portions 13a and 14a can be adjusted by the circular portion 40b without rotating the cam shafts 13 and 14.

  Other configurations and operations are the same as those of the first embodiment, and thus redundant description is omitted.

In the second embodiment, when the shaft-like jig 40 is disposed, the cam cap 18 is also attached. However, the present invention is not limited thereto, and only the cam carrier 17 is attached to the cylinder head 12 with the bolts 26. The shaft-shaped jig 40 can be used for centering.
Embodiment 3 of the Invention

  6 to 8 show a third embodiment of the present invention.

  The third embodiment is different from the first embodiment in that the intake camshaft 13 and the exhaust camshaft 14 also serve as a shaft-like jig for positioning the cam carrier 17. Here, the method for assembling the intake camshaft 13 is illustrated and described, and the description of the method for assembling the exhaust camshaft 14 is omitted, but the method for assembling the exhaust camshaft 14 is the same. is there. Further, when the intake and exhaust bearing recesses 17a and 21a are integrally formed on the cam carriers 17 and 21, respectively, the intake camshaft 13 and the exhaust camshaft 14 are assembled at the same time. If the body has an intake side and an exhaust side, assemble them individually, not simultaneously.

  That is, the intake camshaft 13 is provided with a fitting portion 13f adjacent to the journal portion 13b, and the cam carrier 17 and the cam cap 18 are fitted with the fitting portion 13f adjacent to the bearing portion 15. A mated portion 15a to be mated is provided. Here, the fitted portion 15a also serves as a part of the bearing portion 15. As shown in FIGS. 7 and 8, the outer diameter d2 of the fitting portion 13f is larger than the outer diameter d3 of the journal portion 13b. Is formed.

  Accordingly, the clearance c1 between the outer surface of the fitting portion 13f and the inner surface of the fitted portion 15a is configured to be smaller than the clearance c2 between the outer surface of the journal portion 13b and the inner surface of the bearing portion 15.

  Next, a method for assembling the camshaft 13 will be described.

  First, the cam carriers 17 and 21 are loosely fixed to the cylinder head 12 with the bolts 26 as in the first embodiment. Next, the intake camshaft 13 is placed, the flange 13e is brought into contact with the side surface of the cam carrier 21, and each fitting portion 13f of the intake camshaft 13 is fitted to the fitted portion 15a of each cam carrier 17. Then, the cam caps 18 and 22 are covered from above, and final tightening is performed with bolts 26 and 27 (FIGS. 7A and 8A).

  Thereafter, the camshaft 13 is slid by a predetermined amount in the axial direction (leftward in FIGS. 6, 7, and 8), and the fitting portion 13f is detached from the fitted portion 15a.

  In this state, by attaching the cam cap 22, which is a “slide regulating member”, to the cam carrier 21, the cam cap 22 is fitted between the pair of flange portions 13 d and 13 e of the cam shaft 13. The sliding of the camshaft 13 is restricted, and the intake camshaft 13 is maintained at the final position.

  Further, thrust reception during rotation of the intake camshaft 13 is performed by the side surface of the cam cap 22 and the flange portions 13d and 13e of the intake camshaft 13.

  In such a case, it is only necessary to slide the camshaft 13 and restrict the position by the cam cap 22, so there is no need to use the shaft-like jig 30 as in the first embodiment, and the embodiment 1 can be obtained, and workability and the like can be improved.

Other configurations and operations are the same as those of the first embodiment, and thus redundant description is omitted.
[Embodiment 4 of the Invention]

  9 and 10 show a fourth embodiment of the present invention.

  The fourth embodiment is different from the third embodiment in the structure of the fitting portion 13f of the camshaft 13 and the structure of the fitted portion 15a.

  That is, the outer diameter d2 of the fitting portion 13f is larger than the outer diameter d3 of the journal portion 13b, and the inner diameter d4 of the fitted portion 15a is larger than the inner diameter d5 of the bearing portion 15.

  Even in such a case, the mounting position accuracy of the cam carrier 17 and the like is the same as in the third embodiment by sliding the camshaft 13 and engaging / disengaging the fitting portion 13f with the fitted portion 15a. Can be improved.

  Other configurations and operations are the same as those of the third embodiment, and thus redundant description is omitted.

Explanation of symbols

11 Engine (Internal combustion engine)
12 Cylinder head
13 Intake camshaft
14 Exhaust camshaft
13a Air intake cam
14a Exhaust cam
13b, 14b Journal part
13f Mating part
15,16 Bearing part
15a Mated part
17 Cam carrier
17a Bearing recess
18 Cam cap
18a Bearing recess
21 Cam carrier
22 Cam cap
24 Rocker shaft
25 Rocker arm
30,40 Shaft-shaped jig
30a Mating part
40a Positioning part
40b Circular part
d1 Shaft-shaped jig shaft diameter
d2 Outer diameter of mating part
d3 Journal outer diameter
d4 Inside diameter of mated part
d5 Inner diameter of bearing
c1 clearance
c2 clearance

Claims (11)

In a camshaft assembling method for an internal combustion engine in which a camshaft is assembled to a cylinder head via a plurality of cam carriers and cam caps independent for each journal portion.
A shaft-shaped jig having a length extending over the plurality of cam carriers and having a shaft diameter of a fitting portion corresponding to the journal portion larger than the shaft diameter of the journal portion, is prepared.
A camshaft assembling method for an internal combustion engine, wherein the shaft-shaped jig is attached to the cylinder head via the plurality of sets of cam carriers, and the plurality of cam carriers are positioned at predetermined positions. In a camshaft assembling method for an internal combustion engine in which a camshaft is assembled to a cylinder head via a plurality of cam carriers and cam caps independent for each journal portion.
Prepare a shaft-shaped jig in which the shaft diameter of the fitting portion of the portion corresponding to the journal portion of the camshaft that is actually assembled is thicker than the shaft diameter of the journal portion,
The shaft-shaped jig is attached to the cylinder head via the plurality of sets of cam carriers and cam caps, and the plurality of cam carriers are positioned at predetermined positions. Thereafter, the plurality of cam carriers are attached to the cylinder head. The internal combustion engine characterized in that the plurality of cam caps are removed while being fastened, the shaft-shaped jig is replaced with the camshaft that is actually used, and then the plurality of cam caps are fastened. Camshaft assembly method. In a camshaft assembling method for an internal combustion engine in which a camshaft is assembled to a cylinder head via a plurality of cam carriers and cam caps independent for each journal portion.
Prepare a shaft-shaped jig in which the shaft diameter of the fitting portion of the portion corresponding to the journal portion of the camshaft that is actually assembled is thicker than the shaft diameter of the journal portion,
The shaft-shaped jig is attached to the cylinder head via the plurality of cam carriers to position the plurality of cam carriers at predetermined positions, and then the plurality of cam carriers are fastened to the cylinder head. In this state, the camshaft assembling method for an internal combustion engine, wherein the shaft-shaped jig is reassembled with the camshaft that is actually used, and then the plurality of cam caps are fastened.   4. The shaft-shaped jig is provided with a positioning portion, and the cam carrier is positioned in the shaft-shaped jig axis direction by the positioning portion. A camshaft assembling method for an internal combustion engine according to claim 1.   5. The shaft-shaped jig is formed with a circular portion having the same diameter as a base circle of the cam portion at a position corresponding to the cam portion of the cam shaft. The camshaft assembling method for an internal combustion engine according to any one of the above. In the camshaft assembling method for an internal combustion engine in which the camshaft is assembled to the cylinder head via a plurality of cam carriers and cam caps independent for each journal portion.
The camshaft also serves as a shaft-shaped jig for positioning the cam carrier. The camshaft is provided with a journal portion that is held by a bearing portion of the cam carrier and the cam cap, and is adjacent to the journal portion. A fitting portion thicker than the journal portion is provided,
The cam carrier and the cam cap are provided with a fitted portion to which the fitting portion is fitted, adjacent to the bearing portion,
The clearance between the outer surface of the journal part and the inner surface of the bearing part is smaller than the clearance between the outer surface of the fitting part and the inner surface of the fitted part,
The camshaft fitting portion is fitted to the cam carrier and the cam cap fitted portion, and the camshaft is attached to the cylinder head via the cam carrier and the cam cap,
Thereafter, the camshaft is slid in a predetermined amount in the axial direction, the fitting portion is detached from the fitted portion, and in this state, the slide of the camshaft is regulated by attaching a slide regulating member. A camshaft assembling method for an internal combustion engine, characterized in that The mating part serves as a part of the bearing part,
The camshaft assembling method for an internal combustion engine according to claim 6, wherein an outer diameter of the fitting portion is larger than an outer diameter of the journal portion. The outer diameter of the fitting part is larger than the outer diameter of the journal part,
The camshaft assembling method for an internal combustion engine according to claim 6, wherein an inner diameter of the fitted portion is larger than an inner diameter of the bearing portion.   The camshaft assembling method for an internal combustion engine according to claim 6, wherein the slide restricting member is a housing cap provided at an end portion of the camshaft.   A plurality of the cam carriers are disposed along the cam shaft, a rocker shaft is independently disposed on each cam carrier, and a rocker arm is swingably disposed on the rocker shaft. The camshaft assembling method for an internal combustion engine according to any one of claims 1 to 9. The internal combustion engine camshaft assembling method according to any one of claims 1 to 10, wherein the camshaft is assembled to the cylinder head via the cam carrier and the cam cap. organ.

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