JP2010127181A - Hydraulic pressure vane type variable valve mechanism for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic pressure vane type variable valve mechanism for an engine in which overall length can be shortened. <P>SOLUTION: VVT 10A includes a front retainer 13A provided with an inner peripheral portion 13aA, an oil supply housing 12A provided with an outer peripheral portion 12bA which fits into the inner peripheral portion 13aA, and a plurality of seal rings 17A for sealing oil flowing to oil supply portions 13bA, 13cA respectively from oil passages 12eA, 12fA for oil supply between the inner peripheral portion 13aA and the outer peripheral portion 12bA. In the VVT 10A, a holding groove 12gA for holding the seal ring 17A on the outer peripheral portion 12bA is provided. In the VVT 10A, a communication oil passage R communicating between the oil supply portions 13bA, 13cA and the oil passages 12eA, 12fA for oil supply, is formed at a portion between the holding grooves 12gA of the outer peripheral portion 12bA, and moreover, is formed in enlarging manner by reducing heights of wall portions W2, W5 on which acting hydraulic pressure is higher, out of wall portions W which form the holding groove 12gA, lower than peripheral surface of the outer peripheral portion 12bA. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic vane variable valve mechanism for an engine, and in particular, among peripheral parts to be fitted, an oil supply part is provided on one peripheral part, and an oil supply oil passage is provided on the other peripheral part, and further fitted. The present invention relates to a hydraulic vane type variable valve mechanism for an engine provided with a seal ring for preventing oil leakage between peripheral portions.

  Conventionally, a hydraulic vane type variable valve mechanism (hereinafter also simply referred to as VVT) is known for engines. With regard to such VVT, as a technique considered to be related to the present invention, an oil supply structure for shortening the overall length is disclosed in Patent Document 1 or 2, for example. Moreover, as a technique considered to be related to the present invention, a structure for realizing a method of supplying oil from the outer peripheral portion of the vane storage portion is disclosed in Patent Document 3, for example. This structure is advantageous for shortening the overall length.

JP 11-2181010 A JP-A-11-257032 JP-A-9-280020

  Incidentally, the VVT specifically includes, for example, a type of VVT as shown in FIG. 7 (hereinafter referred to as a journal oiling type VVT). In the journal oil supply type VVT, an oil passage is provided so that oil flows in the order of OCV (oil control valve) which is an oil supply control unit, journal, camshaft, and VVT housing. However, in the journal oil supply type VVT, it is difficult to increase the cross-sectional area of the oil passage formed in the journal and the camshaft due to space constraints. For this reason, in the journal oil supply type VVT, there is a problem in that the pressure loss of the oil becomes relatively large, and as a result, the responsiveness of the VVT becomes low.

On the other hand, in the VVT, for example, the type of VVT as shown in FIG. 8 (hereinafter referred to as the center oil supply type VVT) or the type of VVT as shown in FIG. 9 (hereinafter referred to as the outer periphery oil supply type VVT). Called).
In these center oil supply type VVT and outer periphery oil supply type VVT, the two bodies to be coupled are each provided with a peripheral portion that fits together. Of the two bodies having peripheral parts fitted to each other, the peripheral part of the body to be supplied with oil is provided with an oil supply part, and the peripheral part of the body to be supplied with oil is provided with an oil supply passage. Oil is supplied from the oil passage to the oil supply section through the oil passage.
Note that the two bodies to be combined are specifically a VVT housing including an oil supply housing provided with an OCV and a vane in the case of an outer periphery oil supply type VVT, for example, a center oil supply type VVT. As described above, this includes a case where at least one of these is a body (a front retainer in this case) such as a housing that mediates the coupling between them.

  In the center lubrication type VVT, lubrication is performed from the front side of the VVT without using a journal or camshaft. In the outer lubrication type VVT, lubrication is performed from the outer periphery of the VVT housing without using a journal or camshaft. Therefore, it is possible to easily increase the size of the oil passage. For this reason, high responsiveness can be secured with these center oil supply type VVT and outer periphery oil supply type VVT.

However, for example, in the center oil supply type VVT, the peripheral portions to be fitted are portions where a large axis deviation is likely to occur due to a problem in processing accuracy. For this reason, the center oil supply type VVT requires a relatively large clearance between the peripheral portions. However, if this clearance is large, the amount of oil leakage through the clearance increases. For this reason, in the center oil supply type VVT, it is necessary to set a seal ring between the peripheral portions to prevent leakage. As a result, there is a problem in that the total length becomes long depending on the thickness of the set seal ring. there were.
Further, even in the outer periphery oil supply type VVT, there is a problem in that the entire length becomes longer by setting a seal ring between the peripheral portions to be fitted to prevent leakage.
In addition, the center oil supply type VVT has a structure in which the OCV is disposed on the front side of the VVT, and an oil passage for supplying oil from the front side of the VVT is necessary. There is also a situation that it becomes long. For this reason, in the center oil supply type VVT, a technique capable of suitably reducing the total length in view of such circumstances is desired.

  Therefore, the present invention has been made in view of the above problems, and even when a seal ring is set between the peripheral portions to be fitted with each other, the hydraulic vane type of the engine that can suitably shorten the overall length An object is to provide a variable valve mechanism.

  The present invention for solving the above-described problems is fitted with a first body including a first peripheral portion provided with a pair of advance and retard oil supply portions, and the first peripheral portion. A second body including a second peripheral portion provided with a pair of oil supply passages for advance and retard corresponding to the pair of oil supply portions, and between the first and second peripheral portions. A plurality of seal rings that seal oil flowing from the pair of oil supply passages to the pair of oil supply portions, and the first or second peripheral portion includes either one of the peripheral portions. A holding groove for holding the seal ring is provided, and a communication oil passage that communicates the pair of oil supply portions and the pair of oil supply oil passages is provided in the first or second peripheral portion. A wall portion that is formed in a portion of the peripheral portion between the holding grooves and that forms the holding grooves Among them, the height of the wall portion on the side where the acting hydraulic pressure is high is enlarged by making it lower than the peripheral surface of the peripheral portion provided with the holding groove in the first or second peripheral portion, or The communication oil passage is enlarged and formed in a portion of the first peripheral portion corresponding to a region sandwiched between the seal rings, or the communication oil passage is formed between the first and second peripheral portions. The engine is a hydraulic vane type variable valve mechanism that is enlarged between the seal rings with the predetermined clearance being enlarged.

  In addition, the present invention includes a cylindrical first housing that includes an outer peripheral portion provided with a pair of oil supply portions for advancing and retarding angles and that stores a vane provided with an opening on an end surface thereof, and the outer peripheral portion. And an inner peripheral portion provided with a pair of oil supply passages for advance and retard corresponding to the pair of oil supply portions, and further switching the oil supply path to advance and retard Oil that circulates from the pair of oil supply passages to the pair of oil supply portions between the outer periphery and the inner periphery of the second housing having an oil supply control unit that controls the oil supply control unit around the first housing It is preferable to have a configuration including a plurality of seal rings that seal each of them and a cover member that closes the opening and forms a wall portion that holds the seal ring.

  According to this invention, even if it is a case where a seal ring is set between the peripheral parts to fit, a full length can be shortened suitably.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a VVT 10A according to this embodiment in cross section. Specifically, in FIG. 1, the VVT 10 </ b> A is shown as a whole in FIG. 1A, and the portion A shown in FIG. 1A is enlarged in FIG. 1B. VVT 10A is a center fueling type VVT, and is provided in an engine (not shown). The VVT 10A includes an OCV 11, an oil supply housing 12A, a front retainer 13A, a VVT housing 14, a sprocket 15, a vane 16, a seal ring 17A, and bolts 18 and 19.

The OCV 11 is configured to control the phase of the camshaft 30. Specifically, the oil supply path is defined between a path through an oil supply oil path 12eA (described later) and a path through an oil supply oil path 12fA. By switching at, the advance angle and retard angle of the camshaft 30 are controlled. The OCV 11 is provided in the fuel supply housing 12A. The camshaft 30 may be for an intake valve or an exhaust valve.
The oil supply housing 12 </ b> A is fixed to the chain cover 31. The oil supply housing 12A has a cylindrical protrusion 12aA, and the protrusion 12aA includes an outer peripheral part 12bA as a peripheral part. The protrusion 12aA is provided with a pair of oil passages 12cA and 12dA for advance and retard, respectively, extending from the OCV 11 along the axis. The protrusion 12aA further includes an oil supply passage 12eA that communicates with the oil passage 12cA through the outer peripheral portion 12bA, and an oil supply passage 12fA that communicates between the oil passage 12dA and the outside through the outer peripheral portion 12bA. Three holding grooves 12gA are provided in the outer peripheral portion 12bA so as to sandwich the oil supply oil passages 12eA and 12fA therebetween. In the present embodiment, the second body is realized by the fuel supply housing 12A. Note that the oil passages 12cA and 12dA may also be regarded as constituting part of the oil supply oil passages 12eA and 12fA.

  The front retainer 13 </ b> A is fastened to the sprocket 15 with a bolt 18. The front retainer 13 </ b> A and the sprocket 15 sandwich the VVT housing 14, and the bolt 18 is inserted through the VVT housing 14. The front retainer 13A has an inner peripheral portion 13aA as a peripheral portion. The inner peripheral portion 13aA is fitted with the outer peripheral portion 12bA. The inner circumferential portion 13aA is provided with a pair of oil supply portions 13bA and 13cA for advance and retard angles. The pair of oil supply passages 12eA and 12fA are provided corresponding to the pair of oil supply portions 13bA and 13cA. Specifically, the axial positions of the oil supply passage 12eA and the oil supply portion 13bA, and the oil supply passage 12fA and the oil supply portion 13cA are substantially the same. In the present embodiment, the first body is realized by the front retainer 13A.

The VVT housing 14 is a cylindrical member and includes a vane 16 inside. The VVT housing 14 has openings 14a and 14b on both end faces. Of these openings 14a and 14b, the front-side opening 14a is closed by a front retainer 13A, and the rear-side opening 14b is closed by a sprocket 15. That is, the front retainer 13A and the sprocket 15 function as cover members that close the openings 14a and 14b, respectively.
The sprocket 15 is rotationally driven by a chain (not shown). The engine output transmitted to the sprocket 15 through the chain is transmitted in the order of the VVT housing 14, the vane 16, and the camshaft 30. Thereby, the camshaft 30 is rotationally driven.

The vane 16 is fastened to the camshaft 30 by bolts 19. The vane 16 forms an advance oil chamber and a retard oil chamber in the VVT housing 14 with the VVT housing 14. The oil supply portions 13bA and 13cA communicate with the advance oil chamber and the retard oil chamber, respectively. When oil is supplied to the advance angle oil chamber via the oil supply portion 13bA, the vane 16 rotates to the advance side in the VVT housing 14. As a result, the phases of the vane 16 and the camshaft 30 relative to the VVT housing 14 and the sprocket 15 are relatively advanced. On the other hand, when the oil is supplied to the retarding oil chamber via the oil supply portion 13cA, the vane 16 rotates in the VVT housing 14 to the retarding side. As a result, the phases of the vane 16 and the camshaft 30 relative to the VVT housing 14 and the sprocket 15 are relatively retarded.
The seal ring 17A is provided in each holding groove 12gA. The seal ring 17A seals each oil flowing from the pair of oil supply passages 12eA, 12fA to the pair of oil supply portions 13bA, 13cA between the inner periphery 13aA and the outer periphery 12bA.

  FIG. 2 is an enlarged view schematically showing a cross section of a peripheral portion of the pair of oil supply portions 13bA and 13cA as a main portion of the VVT 10A. 2 shows the main part of the VVT 10A in FIG. 2A, and also shows an example of a conventional VVT as a reference in FIG. 2B. As shown in FIG. 2A, in the VVT 10A, the communication oil path R that connects the pair of oil supply portions 13bA and 13cA and the pair of oil supply oil passages 12eA and 12fA is formed on the outer peripheral portion 12bA provided with the holding groove 2gA. Of these, a groove is formed in the portion between the holding grooves 2gA. Further, the communication oil path R includes the wall W1 and W2 that form the holding groove 2gA, the wall W2 that operates on the higher hydraulic pressure, and the wall W5 and W6 that forms the holding groove 2gA. It is enlarged and formed by making the height with the wall portion W5 on the higher side lower than the peripheral surface of the outer peripheral portion 12bA. By thus forming the communication oil passage R in an enlarged manner, the oil passage cross-sectional area can be enlarged as compared with the VVT having the conventional structure shown in FIG. Therefore, in the VVT 10A, the total length can be shortened without causing a decrease in responsiveness until the oil passage cross-sectional area becomes the same size as that of the VVT having the conventional structure. That is, in the VVT 10A, the overall length can be suitably shortened in that responsiveness can be ensured.

  Further, the shortening of the total length can be suitably achieved by, for example, the following VVT 10B. FIG. 3 is a diagram schematically showing a VVT 10B, which is a modification of the VVT 10A, in section along with a conventional VVT. The VVT 10B is substantially the same as the VVT 10A except that it includes an oil supply housing 12B instead of the oil supply housing 12A and a front retainer 13B instead of the front retainer 13A. The oil supply housing 12B is substantially the same as the oil supply housing 12A except that the height of the wall portions W2 and W5 is not particularly low. The front retainer 13B is substantially the same as the front retainer 13A except that the communication oil path R is formed in a groove shape in a portion corresponding to a region sandwiched between the seal rings 17A in the inner peripheral portion 13aB. Has become.

  According to the VVT 10B, the oil passage cross-sectional area can be increased while reducing the thickness of the wall portion W2 and the like as compared with the VVT having the conventional structure. For this reason, even with the VVT 10B, the total length can be shortened without causing a decrease in responsiveness until the oil passage cross-sectional area becomes the same size as that of the VVT having the conventional structure. That is, the overall length can be suitably shortened in that the responsiveness can be secured even with the VVT 10B.

  Further, the shortening of the total length can be suitably achieved by, for example, the following VVT 10C. FIG. 4 is a diagram schematically showing a VVT 10C, which is a modification of the VVT 10A, in section along with a conventional VVT. The VVT 10C is provided with an oil supply housing 12C instead of the oil supply housing 12A, a point provided with a front retainer 13C instead of the front retainer 13A, and a seal ring 17B instead of the seal ring 17A accordingly. Except for this, it is substantially the same as VVT10A.

The oil supply housing 12C and the front retainer 13C have the outer peripheral portion 12bC and the inner peripheral portion 13aC formed so that the clearance is larger than the clearance formed between the outer peripheral portion 12bA and the inner peripheral portion 13aA, and the wall portion W2. And the height of W5 is substantially the same as the oil supply housing 12A and the front retainer 13A, except that the height is not particularly low. In setting the clearance to be enlarged, it is not always necessary to change both the outer peripheral portion 12b and the inner peripheral portion 13a, and only one of them may be changed.
The seal ring 17B is substantially the same as the seal ring 17A except that the radial width is increased in order to adapt to the clearance.

In the VVT 10C, the communication oil path R is enlarged between the seal rings 7B after setting the clearance between the inner peripheral portion 13aC and the outer peripheral portion 12bC to a predetermined clearance. For this reason, according to VVT10C, an oil passage cross-sectional area can be enlarged compared with VVT of the conventional structure, without requiring groove processing like VVT10B, for example. For this reason, even with the VVT 10C, the overall length can be shortened without causing a decrease in responsiveness until the oil passage cross-sectional area becomes the same size as in the case of the conventional VVT. That is, the overall length can be suitably shortened in that the responsiveness can be secured even with the VVT 10C.
Thus, the VVT 10 is suitable for shortening the entire length while ensuring responsiveness even when the seal ring 17 is set as an oil leakage prevention between the inner peripheral portion 13a and the outer peripheral portion 12b to be fitted. Can be aimed at.

  FIG. 5 is a diagram schematically showing a cross section of the VVT 20 according to the present embodiment. The VVT 20 is a peripheral oil supply type VVT, and is provided in an engine (not shown). The VVT 20 includes an OCV 21, an oil supply housing 22, a plate 23, a VVT housing 24, a sprocket 25, a vane 26, a seal ring 27, and a bolt 28.

The OCV 21 is provided in the fuel supply housing 22. The oil supply housing 22 includes an OCV 21 around the VVT housing 24. Thereby, compared with center oil supply type VVT (for example, VVT10A mentioned above in Example 1), full length can be shortened. The oil supply housing 22 includes an inner peripheral portion 22a as a peripheral portion. The oil supply housing 22 is provided with a pair of oil supply passages 22b and 22c for advance and retard that communicate with the OCV 21 and the outside through the inner peripheral portion 22a. In the present embodiment, the second housing is realized by the OCV 21.
The VVT housing 24 is a cylindrical member that houses the vane 26, and has openings 24a and 24b on both end surfaces. Of these openings 24 a and 24 b, the opening 24 a on the front side is closed with a plate 23, and the opening 24 b on the rear side is closed with a sprocket 25. That is, in the present embodiment, the cover member that closes the openings 24a and 24b with the plate 23 and the sprocket 25 is realized.

The VVT housing 24 includes an outer peripheral portion 24c as a peripheral portion. The outer peripheral portion 24c is fitted with the inner peripheral portion 22a. The outer peripheral portion 24c is provided with a pair of oil supply portions 24d and 24e (not shown in FIG. 5) for advance and retard angles. The oil supply passages 22b and 22c are provided corresponding to the oil supply portions 24d and 24e. Specifically, the axial positions of the oil supply passage 22b and the oil supply portion 24d, and the oil supply passage 22c and the oil supply portion 24e are substantially the same. In this embodiment, the first housing is realized by the VVT housing 24.
The sprocket 25 is rotationally driven by a chain (not shown). The engine output transmitted to the sprocket 25 through the chain is transmitted in the order of the VVT housing 24, the vane 26, and the camshaft 30. Thereby, the camshaft 30 is rotationally driven. The sprocket 25 is connected to the VVT housing 24.

The vane 26 is fastened to the camshaft 30 by bolts 28. The vane 26 forms an advance oil chamber and a retard oil chamber between the VVT housing 24 and the VVT housing 24. The oil supply portions 24d and 24e communicate with the advance oil chamber and the retard oil chamber, respectively. When oil is supplied to the advance angle oil chamber via the oil supply portion 24 d, the vane 26 rotates in the VVT housing 24 toward the advance side. As a result, the phases of the vane 26 and the camshaft 30 relative to the VVT housing 24 and the sprocket 25 are relatively advanced. On the other hand, when the oil is supplied to the retarding oil chamber via the oil supply portion 24e, the vane 26 rotates in the VVT housing 24 to the retarding side. As a result, the phases of the vane 26 and the camshaft 30 relative to the VVT housing 24 and the sprocket 25 are relatively retarded.
The seal ring 27 seals each oil flowing from the pair of oil supply passages 22b, 22c to the pair of oil supply portions 24d, 24e between the outer peripheral portion 24c and the inner peripheral portion 22a.

  FIG. 6 is an enlarged view schematically showing a peripheral portion of a pair of oil supply portions 24d and 24e as a main portion of the VVT 20. As shown in FIG. In the VVT 20, the central seal ring 27 is held by walls W <b> 2 and W <b> 3 provided in the VVT housing 24. On the other hand, since the seal ring 27 on the plate 23 side is urged toward the plate 23 side by hydraulic pressure, it is mainly held by the wall portion W1. Further, since the seal ring 27 on the side of the procket 25 is urged toward the sprocket 25 by the hydraulic pressure, it is mainly held by the wall portion W4. On the other hand, the wall portion W1 that holds the seal ring 27 on the plate 23 side is constituted by the plate 23, and the wall portion W4 that holds the seal ring 27 on the sprocket 25 side is constituted by the sprocket 25, respectively. This eliminates the need for the VVT housing 24 to be provided with these wall portions W1 and W4, so that the entire length can be shortened accordingly.

Further, in the VVT 20, a portion of the oil supply housing 22 where the seal ring 27 on the plate 23 abuts and a portion where the seal ring 27 on the sprocket 25 abuts are each tapered so that the diameter increases outward. As a result, the centrifugal force and the tension of the seal ring 27 can be applied to attach the seal ring 27 to the oil supply housing 22, thereby further reducing the amount of oil leakage.
In the VVT 20, three oil supply portions 24 d and 24 e are formed on both end surfaces of the outer peripheral portion 24 c of the VVT housing 24 by slit processing (see FIG. 7). Thereby, cost reduction can be aimed at compared with the case where oil supply parts 24d and 24e are formed by hole processing with a large processing man-hour.
Thus, even when the VVT 20 has the seal ring 27 set between the inner peripheral portion 22a and the outer peripheral portion 24c to be fitted to prevent oil leakage, it is preferable to shorten the overall length while ensuring responsiveness. Can be planned. Further, the VVT 20 can further reduce the amount of oil leakage and can reduce the cost.

The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.
For example, in the first embodiment, the case where the present invention described in claim 1 is applied to a center oil supply type VVT has been described. However, the present invention described in claim 1 can also be applied to a peripheral oil supply type VVT.

It is a figure which shows VVT10A typically in a cross section. It is a figure which expands and shows the principal part of VVT10A typically by a cross section. It is a figure which shows VVT10B typically in a cross section. It is a figure which shows VVT10C typically in a cross section. It is a figure which shows VVT20 typically in a cross section. It is a figure which expands and shows the principal part of VVT20 typically in a cross section. It is a figure which shows typically the oil supply housing 22 and the vane 26 seen from the end surface side. It is a figure which shows typically an example of the conventional journal oil supply type VVT in cross section. It is a figure which shows typically an example of the conventional center oil supply type VVT in a cross section. It is a figure which shows typically an example of the conventional outer periphery oil supply type VVT in a cross section.

Explanation of symbols

10, 20 VVT
11, 21 OCV
12, 22 Lubrication housing 13 Front retainer 23 Plate 14, 24 Lubrication housing 15, 25 Sprocket 16, 26 Vane 17, 27 Seal ring

Claims (2)

A first body comprising a first circumferential portion provided with a pair of advance and retard oiling portions;
A second body comprising a second peripheral portion fitted with the first peripheral portion and provided with a pair of oil supply passages for advance and retard corresponding to the pair of oil supply portions;
A plurality of seal rings that seal each of the oil flowing from the pair of oil supply passages to the pair of oil supply portions between the first and second peripheral portions;
One of the first and second peripheral portions is provided with a holding groove for holding the seal ring at one of the peripheral portions, and the communication oil passage communicates the pair of oil supply portions and the pair of oil supply oil passages. Is formed in a portion between the holding grooves of the peripheral portion provided with the holding groove in the first or second peripheral portion, and acts on the wall portion forming the holding groove. The height of the wall portion on the side where the hydraulic pressure is high is enlarged by making it lower than the peripheral surface of the peripheral portion provided with the holding groove among the first or second peripheral portions,
Alternatively, the communication oil passage is enlarged and formed in a portion of the first peripheral portion corresponding to a region sandwiched between the seal rings.
Alternatively, an engine hydraulic vane type variable valve mechanism in which the communication oil passage is enlarged between the seal rings after the clearance between the first and second peripheral portions is enlarged to a predetermined clearance. A cylindrical first housing for housing a vane having an outer peripheral portion provided with a pair of advance and retard oil supply portions and having an opening on the end surface;
It includes an inner peripheral portion fitted with the outer peripheral portion and provided with a pair of oil supply passages for advance and retard corresponding to the pair of oil supply portions. A second housing provided with oil supply control means for controlling the retard angle around the first housing;
A plurality of seal rings that seal each of the oil flowing from the pair of oil supply passages to the pair of oil supply portions between the outer peripheral portion and the inner peripheral portion;
A hydraulic vane variable valve mechanism for an engine, comprising a cover member that closes the opening and forms a wall portion that holds the seal ring.

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