JP3028707B2 - Cylinder head structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a cylinder head, and more particularly, to increase the rigidity of supporting an idler mounting bolt without increasing the weight or the overall length, thereby preventing cam timing deviation from occurring and burning. The present invention relates to a cylinder head structure that can prevent engine performance and improve engine performance and durability.

[0002]

2. Description of the Related Art Vehicle engines include an engine having cylinders arranged in series, an engine having cylinders opposed to each other, and an engine having cylinders arranged in a V-shape. An engine with cylinders arranged in a V-shape has one side and the other side bank of the V-shaped cylinder block.
The cylinder heads are mounted on one side and the other side, respectively.

In an engine in which cylinders are arranged in a V-shape, the rotation of a crankshaft supported by a cylinder block is controlled by two one-sided intake and exhaust ports supported by one cylinder head. A timing chain, one side, etc. are respectively connected to the first and second cam shafts and two other first and second cam shafts for intake and exhaust supported by the other side cylinder head via idler sprockets. Some are transmitted and driven by a side cam chain.

An apparatus for transmitting rotation through an idler sprocket is disclosed in Japanese Utility Model Laid-Open No. 2-85803. An apparatus disclosed in this publication is a device for transmitting rotation of a camshaft to a camshaft via an idler sprocket, and includes a cam chamber for accommodating a camshaft of a cylinder head and an idler chamber for accommodating and arranging an idler sprocket. An opening communicating with the cylinder head is formed in the cylinder head, and an idler sprocket is disposed at a position covering the opening.

FIGS. 5 to 7 show a structure of a cylinder head on which an idler sprocket is mounted. In the figure, reference numeral 202 denotes an engine. In the engine 202, a cylinder head 206 is mounted on a cylinder block 204, and a head cover 208 is attached to the cylinder head 206. A bearing cap 210 is attached to a lower portion of a cylinder block 204 of the engine 202, and a crankshaft 212 is pivotally supported.

A crank sprocket 214 is mounted on the crank shaft 212. The cylinder head 206 is provided with first and second camshafts 216 and 218 for intake and exhaust, respectively. First and second cam sprockets 220 and 222 are attached to the first and second cam shafts 216 and 218, respectively.

The cylinder head 206 is provided with an idler mounting boss 224 and an idler mounting hole 226. An idler mounting bolt 228 is provided in the idler mounting hole 226 of the idler mounting boss 224. The idler shaft 230 is supported by the idler mounting bolt 228. The idle shaft 230 is provided with a crank idler sprocket 232 and a cam idler sprocket 234 so as to be pivotally supported. These idler sprockets 232 and 234 are integrally provided and supported by an idler shaft 230.

A timing chain 236 is wound around the crank sprocket 214 and the crank idler sprocket 232. A cam chain 238 is wound around the first and second cam sprockets 220 and 222 and the idler sprocket 234 for cam.

The cam chain 238 is provided with a cam chain tensioner 240 for applying a constant tension.
The cam chain tensioner 240 is connected to the tensioner main body 24.
The pushing body (not shown) held so as to be able to move forward and backward at 2 is pushed against the cam chain 238. In the cam chain tensioner 240, a tensioner-side mounting boss 244 is provided on a tensioner main body 242, and the tensioner-side mounting boss 24 is provided.
4 is formed with a tensioner-side mounting hole 246 and is connected by a tensioner-side connecting portion 248.

The cam chain tensioner 240 is provided with a tensioner mounting boss 25 formed on the cylinder head 206.
0 tensioner mounting bolt 2 into the tensioner mounting hole 252
54, the idler mounting bolt 228 and the tensioner mounting bolt 254 are inserted through the tensioner side mounting holes 246 of the tensioner main body 242, and the idler mounting nut 256 and the tensioner mounting nut 258 are screwed.

Therefore, the idler mounting bolt 238
Is the idler mounting boss 22 of the cylinder head 206.
4 and tensioner body 2 of cam chain tensioner 240
42.

The cylinder head 206 has a shaft support portion of the idler shaft 230, that is, a crank idler sprocket 232 and a cam idler sprocket 234.
An idler lubricating oil passage 260 for supplying lubricating oil is formed between the idler shaft 230 and the idler shaft 230. The idler lubricating oil passage 260 includes a first idler lubricating oil passage 260-1 to which lubricating oil is supplied from the cylinder block 204 side, a second idler lubricating oil passage 260-2 directed toward the idler shaft 230, Third idler lubricating oil passage 260-3 between idler mounting bolt 228 and idler shaft 230
And a fourth idler lubricating oil passage 260-4 directed between the idler shaft 230, the crank idler sprocket 232, and the cam idler sprocket 234.

Reference numeral 262 denotes a tensioner lubricating oil passage for supplying lubricating oil for pushing a pushing body (not shown) of the cam chain tensioner 240. The tensioner lubricating oil passage 262 communicates with the head-side lubricating oil passage 264. Reference numeral 266 denotes a chain cover. The chain cover 266 is attached to the timing chain 23
6 and the cam chain 238 are attached to the cylinder block 204 and the cylinder head 206.

[0014]

Incidentally, in the structure of the conventional cylinder head 206, as shown in FIG. 7, the pulling force F1 and the pulling force F1 of the timing chain 236 are respectively applied to the idler sprocket 232 for the crank and the idler sprocket 234 for the cam. A tensile force F2 by the cam chain 238 acts. The tensile forces F1 and F2 act on the idler mounting bolt 228 via the idler shaft 230. The idler mounting bolt 228 is supported by the idler mounting boss 224 of the cylinder head 206 and the tensioner main body 242 of the cam chain tensioner 240.

However, the tensile force F1 by the timing chain 236 is equal to the tensile force F2 by the cam chain 238.
(F1 >> F2), there is a disadvantage that the idler mounting bolt 228 is deformed. This deformation of the idler mounting bolt 228 impairs the smooth rotation of the idler sprocket 232 for crank and the idler sprocket 234 for cam supported by the idler shaft 230, causing inconvenience that cam timing is shifted and causes idler. Seizure of the shaft 230 with the idler sprocket 232 for the crank and the idler sprocket 234 for the cam is caused, and there is a disadvantage that the performance and durability of the engine 202 are impaired.

Further, in order to solve such inconvenience, it is necessary that the idler mounting boss 224 of the cylinder head 206 and the tensioner main body 242 of the cam chain tensioner 240 have a structure capable of increasing the supporting rigidity.

However, in order to increase the support rigidity of the idler mounting bolt 228, it is necessary to form the idler mounting boss 224, the tensioner-side mounting boss 246 of the tensioner main body 242, and the tensioner-side connecting portion 248 into large shapes. There is a disadvantage that the weight of the engine 202 increases due to an increase in the forming material, and that the entire length of the engine 202 increases due to the large-sized tensioner main body 242 protruding toward the chain cover 266.

[0018]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides an idler shaft for supporting an idler sprocket around which an engine timing chain is wound, and an idler mounting bolt for supporting the idler shaft. An idler lubrication oil passage for supplying lubricating oil to a shaft support portion of the idler shaft, the idler lubrication oil supply passage being configured to provide an idler mounting boss for mounting the idler mounting bolt on the cylinder head of the engine. An oil boss is formed and provided on the cylinder head so as to be in contact with one side in the radial direction of the idler mounting boss, and is branched from the idler lubricating oil passage to provide lubricating oil at a different bearing portion of the idler shaft. The branch lubricating oil boss formed with the branch lubricating oil passage for supplying oil is in contact with the other radial side of the idler mounting boss. Characterized by providing formed in the cylinder head.

[0019]

According to the structure of the present invention, the idler lubricating oil boss formed with the idler lubricating oil passage for supplying the lubricating oil to the shaft support portion of the idler shaft is provided on the engine cylinder head. A branch lubricating oil is formed so as to be in contact with one side in the radial direction of the lubricating oil, and is formed with a branch lubricating oil passage that branches from the idler lubricating oil passage and supplies lubricating oil to a bearing portion of another idler shaft. The boss is formed so as to be in contact with the other radial side of the idler mounting boss. In other words, the idler lubricating oil boss portion and the branch lubricating oil boss portion are formed and provided on the cylinder head so as to be in contact with each other while sandwiching the idler mounting boss portion from both sides in the radial direction. The rigidity of supporting the idler mounting bolt can be increased without using the portion and the branch lubricating oil boss portion to separately form the supporting boss portion.

[0020]

An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. In FIG. 4, reference numeral 2 denotes an engine. The engine 2 has one side and the other side cylinder heads 10 and 12 mounted on one side and the other side cylinder banks 6 and 8 of the V-shaped cylinder block 4, respectively. 12, one-side / other-side head covers 14 and 16 are attached. A bearing cap 18 and an oil pan 20 are attached to a lower portion of the cylinder block 4 of the engine 2. Reference numeral 22 denotes an oil pump.

In the engine 2, a crankshaft 24 is supported on the cylinder block 4 by a bearing cap 18. The crankshaft 24 has a crank sprocket 2
6 is provided. The one-side cylinder head 10
And the other side cylinder head 12, one side first and second camshafts 28 and 30 for intake and exhaust, and the other side first and second camshafts 32 and 34 for intake and exhaust, respectively. , Are pivotally provided. One-side first and second cam sprockets 36 and 38 are attached to the first-side first and second camshafts 28 and 30, respectively. On the other side first and second camshafts 32 and 34,
The first and second cam sprockets 40 and 42 on the other side are attached and provided respectively.

One of the first and second camshafts 28 and 30 supported by the one-side cylinder head 10 and one of the first and second camshafts 28 for intake in the drawing have an idler sprocket for one-side crank. 44 is provided. As shown in FIG. 3, the other-side cylinder head 12 is provided with a boss portion 46 for mounting the other-side idler, and a hole 48 for mounting the other-side idler.

The other side idler mounting hole 48 is provided with another side idler mounting bolt 50 in the other side idler mounting hole 48 of the other side idler mounting boss portion 46. On the other side idler mounting bolt 50,
The other idler shaft 52 is supported. The other idler shaft 52 is provided with an other crank idler sprocket 54 and another cam idler sprocket 56 which are pivotally supported. Each of these idler sprockets 54 and 56
It is provided integrally and is supported by the other idler shaft 52.

An intermediate idler mounting bolt 58 is provided on the cylinder block 4 at a position above the center between the first and second cylinder banks 6, 8, and supports the intermediate idler shaft 60. The intermediate idler shaft 60 is provided with an intermediate idler sprocket 62 pivotally supported.

The crank sprocket 26, the one-side crank idler sprocket 44, the other-side crank idler sprocket 54, and the intermediate idler sprocket 62
, A timing chain 64 is wound around and provided. The one-side first and second cam sprockets 36 and 38 are provided with one-side cam chains 66 wound therearound. The other-side first and second cam sprockets 40 and 42 and the other-side idler sprocket 56 for cams are provided with other-side cam chains 68.
Is provided.

The cylinder block 4 has a timing tensioner 7 for applying a constant tension to the timing chain 64.
0 is provided. Timing chain tensioner 70
Causes the push mechanism 74 to push the push body 74 against the timing chain 64.

The one-side cylinder head 10 is provided with a one-side cam chain tensioner 76 for applying a certain tension to the one-side cam chain 66. The one-side cam chain tensioner 76 pushes the one-side pushing body 80 held by the one-side tensioner main body 78 so as to be able to move forward and backward to the one-side cam chain 66 by an appropriate pushing force applying means.

The other cylinder head 12 is provided with another cam chain tensioner 82 for applying a constant tension to the other cam chain 68. The other-side cam chain tensioner 82 pushes the other-side pushing body 86 held by the other-side tensioner main body 84 so as to be able to move forward and backward to the other-side cam chain 68 by an appropriate pushing force applying means.

The other cylinder head 12 of the engine 2
The other-side cam chain tensioner 82 provided on the inner side is located on the inner side surrounded by the other-side cam chain 68. The other-side cam chain tensioner 82 is provided with a plurality of other-side tensioner-side mounting bosses 88 so as to be positioned at each apex of the other-side tensioner main body 84 having a substantially triangular frame shape. The other-side tensioner-side mounting holes 90 are formed in the respective 88, and these other-side tensioner-side mounting bosses 88 are connected to each other by a tensioner-side connecting portion 92. Further, the other-side cylinder head 12 is provided with a boss portion 94 for mounting the other-side tensioner, and a hole 96 for mounting the other-side tensioner.

The other-side cam chain tensioner 82 has the other-side tensioner main body 84 disposed in the other-side cam chain 68, and the other-side tensioner mounting boss 94 formed in the other-side cylinder head 12. The other-side tensioner mounting bolt 98 is attached to 96, and the other-side idler mounting bolt 50 and the other-side tensioner mounting bolt 98 are mounted by the idler mounting nut 100 and the tensioner mounting nut 102.

Therefore, the other side idler mounting bolt 50
Is supported by the other side idler mounting boss 46 of the other side cylinder head 12 and the other side tensioner main body 84 of the other side cam chain tensioner 82.

The other cylinder head 12 of the engine 2
As shown in FIGS. 1 and 2, a boss portion 104 for the other side idler lubricating oil is formed and provided, and a boss portion 106 for the branched lubricating oil is formed and provided. The other-side idler lubricating oil boss 104 is formed with another-side idler lubricating oil passage 108 for supplying lubricating oil to a bearing portion of the other-side idler shaft 52. The branched lubricating oil boss portion 106 is formed with a branched lubricating oil passage 110 which branches from the other-side idler lubricating oil passage 108 and supplies lubricating oil to a bearing portion of the intermediate idler shaft 60 which is a different idler shaft. You.

The other idler lubricating oil passage 108 is provided with another first idler lubricating oil passage 108-1 to which lubricating oil is supplied from the other cylinder head 12 side, and another idler shaft 5.
The other side idler lubricating oil passage 108 that is directed in two directions
2, the other side idler mounting bolt 50 and the other side idler shaft 5
2, the other third idler lubricating oil passage 108-3 between
The other-side fourth idler lubricating oil passage 108-4 directed between the other-side idler shaft 52 and the other-side crank idler sprocket 54 and the other-side cam idler sprocket 56.
And

The other idler lubricating oil boss 104
Is one side in the radial direction of the other-side idler mounting boss 46 (FIG. 1).
To the right), the other cylinder head 1
2 is provided. The Branch Lubricating Oil Boss 10
6 is formed on the other side cylinder head 12 so as to be in contact with the other side (left side in FIG. 1) in the radial direction of the other side idler mounting boss 46. The branch lubricating oil boss portion 106 is formed on the other side cylinder head 12 so as to be in contact with the other side idler mounting boss portion 46 so that the branch lubricating oil passage 110 communicates with the other side idler lubricating oil passage 108. It is provided.

Thus, as shown in FIG. 1, the other side idler lubrication oil passage 108 is formed in the other side cylinder head 12 to supply lubricating oil to the bearing portion of the other side idler shaft 52. The oil boss 104 is formed and provided so as to be in contact with one radial side of the other idler mounting boss 46. Also, the other cylinder head 12 includes
A boss portion 106 for a branched lubricating oil in which a branched lubricating oil passage 110 that is branched from the other idler lubricating oil passage 108 and supplies lubricating oil to a bearing portion of another intermediate idler shaft 60 is formed.
Is formed so as to be in contact with the other radial side of the other-side idler mounting boss portion 46.

That is, the other-side cylinder head 12 has the other-side idler mounting boss portion 46 sandwiched from both sides in the radial direction.
The other-side idler lubricating oil boss 104 and the branched lubricating oil boss 106 are formed so as to cross each other so as to be in contact with the other-side idler mounting boss 46, respectively. Thus, the other-side idler mounting boss 46 is supported so as to be sandwiched from both sides in the radial direction by the wedge-shaped other-side idler lubricant boss 104 and the branch lubricant boss 106. become.

Reference numeral 112 denotes a lubricating oil passage for the other side tensioner for supplying lubricating oil for pushing the other side pushing body 86 of the other side cam chain tensioner 82. The other side tensioner lubricating oil passage 112 is connected to the other head side lubricating oil passage 1.
14. The other side idler lubricating oil passage 1
Reference numeral 08 communicates with the other head-side lubricating oil passage 114.

Reference numeral 116 denotes a timing chain guide for guiding the timing chain 64. Reference numeral 118 denotes a chain cover that is attached to the cylinder block 4 and the one and other cylinder heads 10 and 12 so as to cover the timing chain 64 and the one and other cam chains 66 and 68.

Next, the operation will be described.

The rotation of the crankshaft 24 of the engine 2 is controlled by the timing chain 64 by the crank sprocket 26.
And the timing chain 64 drives the one-side / other-side crank idler sprockets 44 and 54 via the intermediate idler sprocket 62, and the one-side and other-side cam chains 66 and 68 cause the first-side first and second cams to be driven. Shaft 28
30 and the other first and second camshafts 32 and 34 are driven.

The other side cylinder head 12 of the engine 2
The other idler lubricating oil boss 104 formed with the other idler lubricating oil passage 108 for supplying the lubricating oil to the bearing portion of the other idler shaft 52 is connected to the other idler mounting boss 46 by the diameter. It is formed and provided on the other cylinder head 12 so as to be in contact with one side in the direction.

The other cylinder head 12 is formed with a branched lubricating oil passage 110 which branches from the other idler lubricating oil passage 108 and supplies the lubricating oil to the bearing portion of another intermediate idler shaft 60. The branch lubricating oil boss 106 is formed and provided on the other cylinder head 12 so as to be in contact with the other radial side of the other idler mounting boss 46.

As a result, the other side idler lubricating oil passage 108 is formed on the other side cylinder head 12 and the branched lubricating oil boss 104 is formed on the other side idler lubricating oil passage 110. 106 are formed in a wedge shape so as to be in contact with and be sandwiched from both sides in the radial direction of the other-side idler mounting boss 46 to which the other-side idler mounting bolt 50 is mounted. Therefore, the other-side idler mounting boss portion 46 is supported by the wedge-shaped other-side idler lubricant boss portion 104 and the branch lubricant boss portion 106 so as to be sandwiched from both sides in the radial direction. Become.

As described above, the other side idler mounting bolt 50
The other-side idler mounting boss portion 46 to which the other-side idler lubricating oil passage 108 is formed and the branched lubricating oil boss portion 106 where the branched lubricating oil passage 110 is formed. The support rigidity of the other-side idler mounting bolt 50 can be increased in a conventional space without having to separately form a dedicated support boss portion.

For this reason, according to the structure of the other-side cylinder head 12, the supporting rigidity of the other-side idler mounting bolt 50 can be increased without increasing the weight and the overall length, and the deformation of the other-side idler mounting bolt 50 can be improved. Can be prevented, and smooth rotation of the other-side crank idler sprocket 54 and the other-side cam idler sprocket 56 supported by the other-side idler shaft 52 can be ensured. As a result, it is possible to prevent cam timing deviation from occurring and to prevent seizure of the other idler shaft 52 with the other crank idler sprocket 54 and the other cam idler sprocket 56. Performance and durability can be improved.

[0047]

As described above, according to the present invention, the idler lubricating oil boss and the branch lubricating oil boss are formed on the cylinder head such that the idler mounting boss is sandwiched from both sides in the radial direction and is in contact with each other. With this arrangement, the rigidity of supporting the idler mounting bolt can be increased without using the boss portion for the idler lubricating oil and the boss portion for the branched lubricating oil and separately forming the supporting boss portion.

Therefore, the rigidity of supporting the idler mounting bolt can be increased without increasing the weight and the total length, and the deformation of the idler mounting bolt can be prevented, and the idler sprocket supported by the idler shaft can smoothly rotate. Can be secured. Thus, it is possible to prevent cam timing deviation from occurring and to prevent seizure, thereby improving the performance and durability of the engine.

[Brief description of the drawings]

FIG. 1 is a front view of another cylinder head showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view taken along line 〓-〓 of FIG. 4;

FIG. 4 is a front view of the engine.

FIG. 5 is a front view of a cylinder head showing a conventional example.

FIG. 6 is a cross-sectional view taken along the line II-II of FIG.

FIG. 7 is a sectional view of the engine.

[Explanation of symbols]

 2 Engine 4 Cylinder block 6 Cylinder head 10 One side cylinder head 12 Other side cylinder head 24 Crankshaft 26 Crank sprocket 28/30 One side first / second camshaft 32/34 Other side first / second camshaft 36 ・38 One side first / second cam sprocket 40/42 Other side first / second cam sprocket 44 One side idler sprocket 46 Other side idler mounting boss 48 Other side idler mounting hole 50 Other side idler mounting bolt 52 Other side Idler shaft 54 Idler sprocket for other side crank 56 Idler sprocket for other side cam 58 Intermediate idler mounting bolt 60 Intermediate idler shaft 62 Intermediate idler sprocket 64 Timing chain 66 One side cam chain 68 Other side cam chain 70 Timing chain tensioner 76 One Cam chain tensioner 82 Other side cam chain tensioner 84 Other side tensioner main body 86 Other side pushing body 104 Other side idler lubricating oil boss 106 Branch lubricating oil boss 108 Other side idler lubricating oil passage 110 Branch lubricating oil passage 112 etc. Side tensioner lubricating oil passage 114 Other head side lubricating oil passage

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02F 1/24 F01M 9/10 F02B 67/06 F02F 7/00

Claims (2)

(57) [Claims] 1. An idler shaft for supporting an idler sprocket around which a timing chain of an engine is wound, an idler mounting bolt for supporting the idler shaft, and an idler for mounting the idler mounting bolt to a cylinder head of the engine. A mounting boss portion is formed and provided, and an idler lubricating oil boss portion in which an idler lubricating oil passage for supplying lubricating oil to a bearing portion of the idler shaft is formed on one radial side of the idler mounting boss portion. A boss portion for a branched lubricating oil formed and provided in the cylinder head so as to be in contact therewith and formed with a branched lubricating oil passage for branching from the idler lubricating oil passage and supplying lubricating oil to a bearing portion of another idler shaft. A cylinder formed in the cylinder head so as to be in contact with the other radial side of the idler mounting boss portion. Head structure. 2. The boss portion for an idler lubricating oil and the boss portion for a branched lubricating oil are formed and provided on the cylinder head such that the boss portion for the idler mounting is interposed so as to be in contact with the boss portion from both sides in the radial direction. The structure of the cylinder head according to claim 1, wherein: