JP3070270B2 - Timing chain cover mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for a timing chain cover, and more particularly to a water pump case having a fitting function interposed between a cylinder block and a timing chain cover when positioning the timing chain cover. The present invention relates to a mounting structure of a timing chain cover performed by using the knock pin.

[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 of the V-shaped cylinder block and the other side of the cylinder bank,
The cylinder heads are mounted on one side and the other side, respectively.
In such an engine, one side first and second camshafts for intake and exhaust are respectively supported on one side cylinder head, and two sides for intake and exhaust are respectively provided on the other side cylinder head. The other side first and second camshafts are provided so as to be pivotally supported, and the rotation of the crankshaft that is supported by the cylinder block is rotated by the timing chain and one side and the other side camchain via the intermediate shaft. Some are transmitted to and driven by the second camshaft and the other first and second camshafts.

As a mounting structure of the timing chain cover, there is one disclosed in Japanese Utility Model Laid-Open No. 2-132811. A water pump case structure for an engine disclosed in this publication includes a timing belt that forms a timing belt chamber between a cylinder block and a cylinder head and a front surface of the cylinder block and the cylinder head that is attached to a front surface of the cylinder block and the cylinder head. A rib that includes a cover and a bearing boss of the water pump attached to the cylinder block, and protrudes radially outward of the bearing boss of the water pump so as to substantially surround the bearing boss via a predetermined space. The timing belt cover has an opening formed so that the edge corresponds to the rib, and the edge of the opening is brought into contact with the sealing surface at the tip end of the rib via a sealing member, and the bearing of the water pump is formed. At least a part of the partial boss is located at the same axial position as the timing belt chamber.

FIG. 5 shows a mounting structure of the timing chain cover. In FIG. 5, 20
2 is an engine. In this engine 202, one side and other side cylinder heads 210 and 212 are mounted on two one side and other side cylinder banks 206 and 208 of a V-shaped cylinder block 204, respectively. One side, the other side head cover 21 in 210, 212
4, 216 are attached. A bearing cap 218 is attached to a lower portion of the cylinder block 204 of the engine 202, and an oil pan (not shown) is attached. Reference numeral 220 denotes an oil pump.

The engine 202 includes a cylinder block 20
4, a crank sprocket 224 is attached to one end in the axial direction of a crankshaft 222 which is supported by a bearing cap 218. The one-side cylinder head 21
0 and the other side cylinder head 212, respectively, one side first,
The second camshafts 226 and 228 and the other side first and second camshafts 23
0 and 232 are pivotally provided. One-side first and second cam sprockets 234 and 236 are attached to the first-side first and second camshafts 226 and 228, respectively, at the other end in the axial direction. The other first and second camshafts 230 and 232 have the other first and second cam sprockets 23 at one end in the axial direction, respectively.
8, 240 are attached.

The first and second cam shafts 226, 228
On the other hand, in the figure, one side intermediate sprocket 242 having a diameter larger than that of the crank sprocket 224 is attached to one end of the first side camshaft 226 for intake in the axial direction. The other side cylinder head 212 is provided with another side idler shaft 244 attached to one end side in the axial direction by bolts 246. This other side idler shaft 24
4 is provided with the other-side intermediate idler 250 pivotally supported. The other-side intermediate idler 250 includes an other-side intermediate sprocket 252 and another-side cam sprocket 254, and the other-side intermediate sprocket 252 and the other-side cam sprocket 254 are provided integrally.

The cylinder block 204 has one side,
An idle shaft 256 is mounted on one end side in the axial direction by an idle shaft mounting bolt 258 so as to be located between the other cylinder banks 206 and 208. This idle shaft 256
, The idle sprocket 260 is supported.

[0008] A timing chain 262 is wound around the crank sprocket 224, the one-side intermediate sprocket 242, the other-side intermediate sprocket 252, and the idle sprocket 260. The one-side first and second cam sprockets 234 and 236 are provided with one-side cam chains 2.
64 are wound around. The other-side first and second cam sprockets 238 and 240 and the other-side cam sprocket 25
4 is provided around the other side cam chain 266.

The timing chain 262 is provided with a timing tensioner 268 for applying a constant tension. The one side cam chain 264 and the other side cam chain 26
6 is provided with a one-side camch tensioner 270 and the other-side camch tensioner 272 for applying a constant tension. Reference numeral 274 denotes a chain guide for guiding the timing chain 262, and 276 denotes a water pump.

[0010] The timing chain 262 is surrounded by a timing chain cover 296.

[0011]

By the way, in the conventional timing chain cover mounting structure, as shown in FIG. 5, two engagement holes 310-1 and 310-2 on the lower side and both sides of the cylinder block 204. This is performed by a not-shown knock pin that engages with.

As a result, when positioning the timing chain cover, two dowel pins are required, the number of parts is large, and two engagement holes 310-3 are formed in each of the cylinder block and the timing chain cover. 1,3
It is necessary to drill 10-2, which is disadvantageous in that it requires a large number of processing steps and is practically disadvantageous.

[0013] Further, the through hole as a seal portion formed in the timing chain cover has a rough state having a predetermined gap with respect to the seal portion of the water pump case, that is, a loose state, in order to eliminate a displacement during processing. As shown in FIG. 4, when the timing chain cover 296 is attached to the cylinder block, the center C1 of the sealing region 296S formed of an O-ring of the timing chain cover 296 and the sealing region 284 of the water pump case 284, as shown in FIG.
There is a disadvantage that the center of the S is shifted from the center C2, the reliability of the seal is reduced, and this is disadvantageous in practical use.

[0014]

SUMMARY OF THE INVENTION In order to eliminate the above-mentioned disadvantages, the present invention provides a timing chain for transmitting a rotational force from a crankshaft of a V-type engine to a camshaft on a side of a cylinder block of the engine. A knock chain engaging hole for disposing a knock pin on the side surface of the cylinder block is provided and a timing chain cover mounting structure for positioning by the knock pin when the timing chain cover is arranged to surround the timing chain. A water pump is provided in a cylinder block constituting one bank of the V-type engine and surrounded by the timing chain, and the cylinder block and the timing chain are provided on an outer peripheral surface of a water pump case constituting the water pump. Form the fitting parts to be fitted to the cover respectively. And, characterized in that the formation of the knock pin engaging hole portion outside of the other bank is provided with the seal member for sealing the respective radially fitting portion.

[0015]

According to the invention described above, when attaching the timing chain cover, a water pump case having a fitting function is interposed between the cylinder block and the timing chain cover. With the use of knock pins, accurate positioning is achieved, and the number of knock pins is reduced.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 3 show an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes a V-type engine. In this engine 2, one side and other side cylinder heads 10 and 12 are mounted on two one side and other side cylinder banks 6 and 8 of a V-shaped cylinder block 4, respectively. One side, the other side head cover 1 for 10 and 12
4 and 16 are attached. A bearing cap 18 is attached to a lower portion of the cylinder block 4 of the engine 2 and an oil pan (not shown) is attached. In addition,
Reference numeral 20 denotes an oil pump.

The engine 2 has a crank sprocket 24 attached to one end in the axial direction of a crankshaft 22 rotatably supported by the cylinder block 4 by a bearing cap 18. The one-side cylinder head 10
And the other-side cylinder head 12, one-side first and second camshafts 26 and 28 for intake and exhaust, and the other-side first and second camshafts 30 and 32 for intake and exhaust, respectively. It is rotatably supported. One side first and second camshafts 26 and 28 have one side first and second cam sprockets 3 at the other end in the axial direction, respectively.
4, 36 are provided. The other first and second camshafts 30 and 32 have first and second cam sprockets 38 and 40 attached to one end in the axial direction, respectively.

One of the two first-side first and second camshafts 26, 28 supported by the one-side cylinder head 10, one end of the one-side first camshaft 26 for intake in the drawing has one axial end. The one side intermediate sprocket 42 larger in diameter than the crank sprocket 24 is attached to the side.

The other first side of the other side cylinder head 12,
A fixing bolt fixing hole (not shown) of a fixing stud bolt 46 for supporting the other idler shaft 44 is formed at an intermediate portion between the second camshafts 30 and 32 and the crankshaft 22 and at one end in the axial direction. Have been. The stud bolt 46 is fixed to the bolt fixing hole.

On the outer periphery of the other-side idler shaft 44, another-side intermediate idler 50 is supported. This other-side intermediate idler 50 is formed of another-side intermediate sprocket 52 and a other-side cam sprocket 54.

Further, an idle shaft 56 is mounted on the cylinder block 4 at a position above the center between the one and the other cylinder banks 6 and 8 at one end in the axial direction with an idle shaft mounting bolt 58. I have. An idle sprocket 60 is rotatably supported on the idle shaft 56.

A timing chain 62 is wound around the crank sprocket 24, the one-side intermediate sprocket 42, the other-side intermediate sprocket 52 and the idle sprocket 60 of the other-side intermediate idler 50. The one-side first and second cam sprockets 34 and 36 are provided with a one-side cam chain 64 wound therearound. The other-side first and second cam sprockets 38 and 40 and the other-side cam sprocket 5
4, the other side cam chain 66 is wound around and provided.

The timing chain 62 is provided with a timing tensioner 68 for applying a constant tension. The one-side cam chain 64 and the other-side cam chain 66 are provided with a one-side cam chain extender 70 and a second-side cam chain extender 72 for applying a constant tension. Reference numeral 74 denotes a timing chain guide for guiding the timing chain 62, and reference numeral 76 denotes a water pump. At this time, the water pump 76 is connected to the cylinder block 4 constituting the one side cylinder bank 6 which is one bank of the engine 2.
And provided at a portion surrounded by the timing chain 62.

The front wall 4 of the cylinder block 4
As shown in FIG. 3, a pump mounting portion 78 is formed at the portion a. The pump mounting portion 78 is formed by a block-side bolt hole (not shown), a mounting recess 80, and a block-side engaging portion 82. This pump mounting portion 78
Is for mounting a water pump 76.

The water pump 76 has a water pump case 84, a shaft 86, and an impeller 88. Fitting portions fitted to the outer peripheral surface of the water pump case 84 to the cylinder block 4 and a timing chain cover 96 described later, that is, first and second fitting portions 90-.
1, 90-2 are formed, and the water pump case 8 is formed.
A first fitting portion 90-1 that fits into the cylinder block 4 is formed at one end portion (right side in FIG. 3) of the cylinder block 4, and a case-side bolt hole portion 92 through which a block mounting bolt (not shown) is inserted. Are formed. A second fitting portion 90-2 that fits into the timing chain cover 96 is formed at an intermediate portion of the water pump case 84, and a drain hole 94 is formed.

The other end portion (left side in FIG. 3) of the water pump case 84 passes through a through hole 98 provided in a timing chain cover 96 surrounding the timing chain 62, and the timing chain cover 96 And the second fitting portion 90-2 is fitted into the through hole 98.

The through hole 9 as the second fitting portion 90-2
An oil seal member 100 for a cover, which is a seal member for sealing in the radial direction, is interposed at a contact portion between the water pump case 8 and the water pump case 84.

In the water pump case 84, a shaft 86 is supported by a bearing member 102.
The shaft 86 has an impeller 88 fixed at one end (right side in FIG. 3), and a water pump sprocket (not shown) fixed at the other end (left side in FIG. 3) via a fixing member 104. ing.

In the water pump 76, a first fitting portion 90-1 is fitted into a block side engaging portion 82 of a pump mounting portion 78 so as to position the impeller 88 in the mounting concave portion 80 of the cylinder block 4. Between the block side engaging portion 82 and the first fitting portion 90-1, there is a block oil seal member 10 which is a seal member for radially sealing.
6 are interposed. The water pump 76 is fastened and fixed to the pump mounting portion 78 by a block mounting bolt (not shown). At this time, the impeller 88
A swirl chamber 108 is formed by the and the mounting recess 80.

A knock pin engaging hole 110 for disposing a single knock pin (not shown) is provided on a side surface of the cylinder block 4, and the knock pin engaging hole 110 is provided on the other side of the engine 2 as the other bank of the engine 2. 8
Formed on the outer side of.

More specifically, a knock pin engaging hole 110 is formed on the lower right side of the cylinder block 4 in FIG. 1, and an engaging hole (not shown) for a knock pin is also formed in the timing chain cover 96.

The positioning of the timing chain cover 96 is determined by adjusting the position of the through hole 98 of the timing chain cover 96 and the second fitting portion 90 on the outer periphery of the water pump case 84.
-2 and the only knock pin is used for the engagement portion with the engagement surface portion 112.

Next, the operation will be described.

When attaching the timing chain cover 96, first, the water pump 76 is mounted on the cylinder block 4 using the first fitting portion 90-1, and the outer periphery of the water pump case 84 of the water pump 76 is set. The through hole 98 of the timing chain cover 96 is engaged with the engagement surface 112 of the second fitting portion 90-2.

The knock pin engagement hole 110 on the lower right side of the cylinder block 4 and the timing chain cover 9
The timing chain cover 96 is positioned by connecting the engaging hole 6 (not shown) with a knock pin (not shown).

Thus, the water pump case 8
4, that is, a first fitting portion 90-
1, the water pump case 84 can be mounted at an accurate position with respect to the cylinder block 4, and the fitting portion formed on the outer peripheral surface of the water pump case 84, that is, the second fitting portion 90-2, The timing chain cover 96 and the water pump case 84 can be mounted at accurate positions. And a water pump case 84 attached at an accurate position,
A knock pin engaging hole 1 provided at a position distant from the water pump case 84 attached to the one-side cylinder bank 6 which is one bank of the engine 2, that is, on the outer side of the other cylinder bank 8 which is the other bank of the engine 2.
According to 10, when the timing chain cover 96 is provided, the timing chain cover 96 can be accurately attached by using the water pump case 84 as a knock pin, and the number of knock pins can be reduced.

The center of the sealing portion of the timing chain cover 96 and the center of the sealing portion of the water pump case 84 are made to substantially coincide with each other by accurate and tight fitting of the timing chain cover 96 and the water pump case 84. Water pump case 84
The timing chain cover 96 becomes uniform.
Sealability can be improved.

Further, since the sealing portion of the timing chain cover 96 and the sealing portion of the water pump case 84 are provided in the radial direction, the sealing surface of the timing chain cover 96 is in the same direction as the vibration.
The change in surface pressure due to vibration is small, the seal is hardly displaced, and the sealability can be further improved.

[0040]

As described above in detail, according to the present invention, the timing chain for transmitting the rotational force from the crankshaft of the V-type engine to the camshaft is provided on the side of the cylinder block of the engine and on the side of the cylinder block. In the mounting structure of the timing chain cover for positioning the knock chain when the timing chain cover is provided so as to surround the timing chain by providing a knock pin engaging hole for mounting the knock pin, one bank of the V-type engine is formed. A water pump is provided in a portion of the cylinder block that is surrounded by the timing chain, and a fitting portion that fits into the cylinder block and the timing chain cover is formed on an outer peripheral surface of a water pump case that configures the water pump, Seal members are provided at the fittings to seal radially. In addition, since the knock pin engagement hole is formed on the outer side of the other bank, the water pump case can be mounted at an accurate position with respect to the cylinder block by the fitting portion formed on the outer peripheral surface of the water pump case. The fitting portion allows the timing chain cover and the water pump case to be mounted at accurate positions. The timing is determined by the water pump case attached at the correct position and the knock pin engaging hole provided at a position distant from the water pump case attached to one bank of the engine, that is, the outside of the other bank of the engine. When the chain cover is provided, the water pump case can be used as a knock pin to accurately attach the timing chain cover, and the number of knock pins can be reduced. In addition, by accurate and tight fitting of the timing chain cover and the water pump case, the center of the sealing region of the timing chain cover and the center of the sealing region of the water pump case can be substantially aligned, and The gap with the timing chain cover becomes uniform, and the sealing performance can be improved. Further, since the sealing portion of the timing chain cover and the sealing portion of the water pump case are provided in the radial direction, the sealing surface of the timing chain cover is in the same direction as the vibration, and the change in the surface pressure due to the vibration is small. In addition, the seal is hardly displaced, and the sealing performance can be further improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an engine showing an embodiment of the present invention.

FIG. 2 is a schematic view showing a timing chain cover mounted on an engine.

FIG. 3 is a schematic enlarged sectional view of the water pump taken along line III-III in FIG. 2;

FIG. 4 is a schematic view showing a shift between the center of the sealing portion of the timing chain cover and the center of the sealing portion of the water pump case according to the prior art of the present invention.

FIG. 5 is a schematic diagram of an engine.

[Explanation of symbols]

 2 Engine 4 Cylinder block 10 One side cylinder head 12 Other side cylinder head 14 One side head cover 16 Other side head cover 20 Oil pump 22 Crankshaft 26 One side first camshaft 28 One side second camshaft 30 Other side first camshaft 32 other side second camshaft 44 other side idler shaft 56 idle shaft 62 timing chain 64 one side cam chain 66 other side cam chain 76 water pump 84 water pump case 90-1 first fitting part 90-2 second fitting part 96 Timing chain cover 98 Through hole 100 Oil seal member for cover 102 Bearing member 104 Fixing member 106 Oil seal member for block 110 Knock pin engagement hole 112 Engagement surface

Claims (1)

(57) [Claims] A knock pin engaging hole for providing a timing chain for transmitting a rotational force from a crankshaft of a V-type engine to a camshaft on a side surface of a cylinder block of the engine and a knock pin disposed on a side surface of the cylinder block.
The provided parts, in the mounting structure of the timing chain cover for positioning by the knock pin when arranging the timing chain cover so as to surround the timing chain, a cylinder block constituting one bank of the V-type engine A water pump is provided at a portion surrounded by the timing chain, and fitting portions for fitting the cylinder block and the timing chain cover are formed on an outer peripheral surface of a water pump case constituting the water pump. A timing chain cover mounting structure, characterized in that a seal member for radially sealing is provided in each of the portions, and the knock pin engagement hole portion is formed in an outer portion of the other bank.