WO2008004362A1

WO2008004362A1 - Valve timing adjustment device

Info

Publication number: WO2008004362A1
Application number: PCT/JP2007/057470
Authority: WO
Inventors: Koji Yudate; Akira Sakata; Hiroyuki Kinugawa
Original assignee: Mitsubishi Electric Corporation
Priority date: 2006-07-05
Filing date: 2007-04-03
Publication date: 2008-01-10
Also published as: JP2009215881A

Abstract

A valve timing adjustment device having a first rotating body (1) and a second rotating body (2). The first rotating body (1) has a housing (5) having a gear for transmitting power from a crankshaft and also having a shaft insertion hole formed in the center of the housing, a case (3) having projecting shoes (3a) in its inside and forming hydraulic pressure chambers between the shoes (3a), and a cover (4) for closing the opening on one end side of the case (3). The second rotating body (2) has vanes (2b) located between the shoes (3a) to divide each hydraulic pressure chamber into a timing advance chamber and a timing retardation chamber, pivotable in the first rotating body (1), and fixed to an intake or exhaust cam shaft. The cover (4) and housing (5) that are arranged so as to close openings on both sides of the case (3) to which the second rotating body (2) is assembled is integrally fixed to the case (3). The case (3) and the housing (4) are integrally joined together by sintering.

Description

Valve timing adjustment device

Technical field

TECHNICAL FIELD [0001] The present invention relates to a valve timing adjusting device that controls the opening / closing timing of an intake valve or an exhaust valve in an internal combustion engine such as an engine (hereinafter referred to as an engine).

Background art

[0002] The nove timing adjustment device is roughly composed of a first rotating body and a second rotating body. The first rotating body includes a power transmission gear from the crankshaft, a housing having a shaft insertion hole in the center, a case having a plurality of protrusions on the inner side and forming a hydraulic chamber between the casings, The three covers that close the opening are fixed together and rotate together with the crankshaft.

[0003] The second rotating body has a plurality of vanes that divide the hydraulic chamber into an advance hydraulic chamber and a retard hydraulic chamber, respectively, and rotate by a predetermined angle within the assembled first rotary body. Is possible. It is fixed integrally with the intake or exhaust camshaft. The hydraulic chamber described above is configured such that the hydraulic pressure of an oil pump that supplies oil to the engine sliding portion is supplied and discharged, and the relative position of the second rotary body with respect to the first rotary body is controlled by this hydraulic pressure. Speak.

[0004] Here, the first rotating body in the conventional valve timing adjusting device is arranged so that the cylindrical case with both ends in the axial direction opened is sandwiched between the cover and the housing, and the cover, the case, and the housing are integrated by bolts. A structure that is fastened and fixed to is generally used. In this case, depending on the bolt fastening location, the outer peripheral edge of the cover may be warped, and a clearance may occur at the contact portion between the cover and the case, resulting in oil leakage.

[0005] In order to reduce the warping of the cover as described above, it is possible to increase the number of fastening bolts, or to increase the thickness of the cover to such an extent that warpage does not occur. It is also disadvantageous in terms of cost. In addition, it is conceivable to use a hard material for the cover, but it is sometimes difficult to reduce oil leakage due to performance and mounting restrictions when fastening with bolts. [0006] As a solution to such a problem, there is a valve timing adjusting device disclosed in Patent Document 1, for example. In this valve timing adjusting device, the case and the cover are integrally formed by aluminum die casting or the like, thereby eliminating the occurrence of clearance between the cover and the case and preventing oil leakage.

Patent Document 1: Japanese Patent Application Laid-Open No. 11 117717

[0008] In the valve timing adjusting device disclosed in Patent Document 1, the case and the cover are integrally formed by aluminum die casting or the like. FIG. 5 is a view showing an integrally molded part of a case and a cover formed by aluminum die casting or the like, and is a cross-sectional view along the axial direction of the camshaft. As shown in FIG. 5, when a bowl-shaped part 100 in which a case and a cover are integrated is manufactured by molding by aluminum die casting or the like, it is necessary to form a taper part 100a for removing the mold product strength.

[0009] For this reason, in order to incorporate the integrally molded component 100 into the valve timing adjusting device, the taper portion 100a has to be completely removed by cutting, which increases the processing cost. In the case of integral molding, the cover and the case are inevitably made of the same material, which limits the degree of freedom in manufacturing.

[0010] The present invention has been made to solve the above-described problems, and obtains a valve timing adjusting device capable of reducing the number of parts that require cutting and improving the degree of manufacturing freedom. For the purpose.

Disclosure of the invention

[0011] A valve timing adjusting device according to the present invention has a gear for transmitting power from a crankshaft, a housing having a shaft through hole in the center, and a plurality of protrusions on the inner side. A first rotating body having a case that forms a hydraulic chamber, a cover that closes an opening on one end side of the case, and a plurality of chambers that are positioned between the shunts to divide the hydraulic chamber into an advance hydraulic chamber and a retard hydraulic chamber And a second rotating body fixed to the intake or exhaust camshaft, and closing the openings on both sides of the case in which the second rotating body is assembled. In the nove timing adjustment device in which the cover and the housing arranged in this way are fixed integrally with the case, the case and the cover are integrally joined by sintering bonding. [0012] According to the present invention, since the case and the cover are integrally formed by sintering bonding, there is an effect that oil leakage can be drastically reduced even if the valve timing adjusting device works. In addition, since the case and the cover can be formed separately, it is possible to greatly reduce the cutting site without the need to form a die-cut taper when integrally molded. Furthermore, since it can be joined in a solid phase, high dimensional accuracy of the sintered part can be maintained. Furthermore, since different types of materials can be joined, the range of materials that can be used for the cover can be expanded, and the degree of freedom in manufacturing can be improved.

Brief Description of Drawings

FIG. 1 is a diagram showing an internal configuration of a valve timing adjusting device according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 of the valve timing adjusting device in which the second rotating body is at the most retarded position with respect to the first rotating body.

FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1 of the valve timing adjusting device in which the second rotating body is at the most advanced angle position with respect to the first rotating body.

FIG. 4 is a diagram showing another configuration example of the valve timing adjusting apparatus according to the first embodiment.

FIG. 5 is a view showing an integrally formed part of a case and a cover formed by aluminum die casting or the like.

BEST MODE FOR CARRYING OUT THE INVENTION

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

Embodiment 1.

FIG. 1 is a diagram showing an internal configuration of a valve timing adjusting apparatus according to Embodiment 1 of the present invention, and shows an axial cross section. FIG. 2 is a radial cross-sectional view taken along line AA in FIG. 1, and shows a state where the second rotating body is at the most retarded position with respect to the first rotating body. FIG. 3 is a radial cross-sectional view taken along line AA in FIG. 1, showing a state in which the second rotating body is at the most advanced position with respect to the first rotating body.

[0015] The nove timing adjustment device according to the first embodiment is provided in a first rotating body 1 that rotates synchronously through a crankshaft of an engine (not shown) and a chain, and in the first rotating body 1, And a second rotating body 2 fixed integrally to an end face of an intake or exhaust camshaft (hereinafter referred to as a camshaft) (not shown).

As shown in FIG. 2, the first rotating body 1 has a cylindrical shape with both ends in the axial direction opened, and a plurality of syu 3a projecting inward in the radial direction of the cylindrical shape is formed. A case 3, a cover 4 that closes one open end of the case 3, and a housing 5 that closes the other end of the case 3 are provided. Note that the case 3 and the cover 4 are integrally fixed by sintering bonding as shown by a thick line in FIG. 1, and the housing 5 is fastened and fixed to the case 3 by bolts 6.

[0017] The second rotating body 2 has a boss portion 2a and a plurality of vanes 2b projecting outward in the radial direction of the outer peripheral portion of the boss portion 2a. In the second rotating body 2, the camshaft is inserted into the center hole 5a of the housing 5 and the insertion hole la formed in the axial direction of the boss portion 2a communicating with the hole 5a, and is shown on the insertion side end face of the force shaft. The boss 2a is fastened by a center bolt (not shown) inserted from the hole lb side through a non-contact washer. As a result, the second rotating body 2 and the camshaft are fixed together.

[0018] The vane 2b is an advance hydraulic pressure that is supplied with hydraulic pressure when rotating the second rotary body 2 relative to the first rotary body 1 in the advance side relative to the plurality of inner spaces partitioned by the shear 3a. The chamber 7 is divided into a retarding hydraulic chamber 8 that receives hydraulic pressure when the second rotating body 2 is rotated relative to the first rotating body 1 in the retarding direction.

[0019] Each advance hydraulic chamber 7 communicates with an advance oil passage 9 for supplying and discharging hydraulic pressure, and each retard hydraulic chamber 8 with a retard oil passage 10 for supplying and discharging hydraulic pressure. . In the vane 2b, a seal 11 for preventing oil leakage from the advance hydraulic chamber 7 and the retard hydraulic chamber 8 is inserted into the outer peripheral surface that contacts the inner peripheral surface of the case 3, and the plate panel 12 is attached to the outer side in the radial direction. It is energized. The end surface of the shoe 3a that contacts the outer peripheral surface of the vane 2b has a small clearance in order to prevent the oil flow between the advance hydraulic chamber 7 and the retard hydraulic chamber 8, but is separate. This may be dealt with by providing a sealing means.

[0020] A storage hole 13 penetrating from the inside to the outside in the radial direction is formed in any of the cases 3a of the case 3. In this storage hole 13, there are provided a substantially cylindrical lock pin 14 that can reciprocate, a compression panel 15 that always urges the lock pin 14 radially inward, and a stopper 16 that engages one end of the compression panel 15. ing. The stopper 16 is received by the urging force of the compression panel 15. The retaining pin 17 is integrated with the case 3 so as not to fall out from the receiving hole 13. In addition, a communication hole 16a with the outside is provided at the center of the stopper 16.

[0021] On the outer peripheral surface of the boss portion 2a, when the relative position of the second rotating body 2 with respect to the first rotating body 1 is the most retarded position, the lock pin 14 is radially inward by the urging force of the compression panel 15. A fitting hole 18 is formed to fit forward. A release oil passage 19 communicates with the fitting hole 18.

In the above description, the example in which the lock pin 14 is provided in the storage hole formed in the radial direction has been described. However, the storage hole formed in the vane 2b parallel to the axial direction of the first rotating body 1 has the inside of the storage hole. It is also possible to provide a lock pin that can be reciprocally slidable with the lock pin, and the lock pin is fitted into a fitting hole provided in this sliding direction so as to control the relative rotation of the rotor.

Next, the operation will be described.

When the relative position of the second rotating body 2 with respect to the first rotating body 1 is at the most retarded position, the lock pin 14 is fitted in the fitting hole 18 by the urging force of the compression panel 15.

In the case of the advance angle operation, hydraulic pressure is supplied to the fitting hole 18 through the release oil passage 19 and is received by the tip of the lock pin 14. The lock pin 14 slides radially outward in the accommodation hole 13 against the urging force of the compression panel 15, and the fitting state with the fitting hole 18 is released. The second rotating body 2 with the lock pin 14 disengaged is supplied with oil into the advance hydraulic chamber 7 via the advance oil passage 9, and the oil in the retard hydraulic chamber 8 is retarded. By being discharged through the oil passage 10, it is relatively rotated toward the advance side.

[0024] In the case of retarding operation, oil is supplied into the retarded hydraulic chamber 8 via the retarded oil passage 10, and the oil in the advanced hydraulic chamber 7 is discharged through the advanced oil passage 9. Rotate relative to the retard side. Here, when the relative position of the second rotating body 2 with respect to the first rotating body 1 becomes the most retarded position, the mouth pin 14 slides radially inward in the housing hole 13 by the urging force of the compression panel 15, Fits into the fitting hole 18.

Next, the sintered joining of the case 3 and the cover 4 will be described.

In the first embodiment, after the case 3 and the cover 4 are separately formed, they are placed at a predetermined combination position, and heated in a sintering furnace at a temperature equal to or lower than the melting point of the case 3 and the cover 4 to be baked. At the same time as ligation, the solid phase is joined. In this sintered joining, the contact part of the members to be joined At this time, diffusion (diffusion of metal molecules) occurs at the atomic level, and a strong bond without defects can be realized.

[0026] Since the case 3 and the cover 4 are firmly joined in this way, even if the outer peripheral end portion of the cover 4 is slightly warped, the joint portion force between the case 3 and the cover 4 does not leak oil. Also, since case 3 and cover 4 are created separately and force-sintered, it is not necessary to provide a die-cut taper on the inner wall of case 3, unlike when the case and cover are integrally molded with aluminum die casting or the like. The cutting part can be greatly reduced. In addition, since it can be joined in a solid phase, it is possible to maintain high dimensional accuracy compared to fusion welding.

[0027] Further, in the sintered bonding, it is possible to join different materials. Using this characteristic, it is also possible to use a general-purpose iron or aluminum thin member, for example, which is not a high-strength material. Alternatively, a member made by sheet metal press molding may be used as a cover 4 to be sintered and joined to the case 3 of the sintered part. In this case, it is also easy to create a countersunk screw portion (tapered hole portion into which the head of the bolt 6 in FIG. 1 fits) in the axial direction of the first rotating body 1 in the cover 4.

[0028] As described above, according to the first embodiment, since the case 3 and the cover 4 are assembled together by sintered joining, oil leakage from the valve timing adjusting device can be drastically reduced. it can. Since the case 3 and the cover 4 can be made separately, it is possible to greatly reduce the cutting site without having to form a die-cut taper when integrally molded. In addition, since it can be joined in a solid phase, high dimensional accuracy of the sintered part can be maintained. Furthermore, since different types of materials can be joined, the range of materials that can be used for the cover is expanded, and the degree of manufacturing freedom can be improved. For example, only the cover 4 is not a high-strength material different from the case 3, and it is also possible to use a general-purpose iron or aluminum thin material.

[0029] In the first embodiment, the plate thickness is thin! The cover 4 side force is also inserted. The force shown in the example in which the housing 5 is fastened with the bolt 6. As shown in FIG. The case 3 and the housing 5 may be fastened with the bolt 6 inserted from the side. In this case, the bolt hole 6a formed in the shoe 3a must be a screw hole.

[0030] In the first embodiment, the cover 4 and the case 3 which are thinner than the nodling and the udging 5 are sintered. Although an example of joining together by joining is shown, when the thickness of the housing 5 is smaller than that of the cover 4, the case 3 and the housing 5 may be sintered and joined. In this configuration, the case 3 and the thin housing 5 can be made of different materials. For example, the plate is thin, the side member is not a high-strength material, a general-purpose iron or aluminum material is thin, It is also possible to use members.

Industrial applicability

As described above, the valve timing adjusting device according to the present invention can drastically reduce oil leakage by integrating the case and the cover together by sintering, so that the intake valve in an internal combustion engine such as an automobile engine can be greatly reduced. Or it is suitable for use in a valve timing adjustment device that controls the opening and closing timing of the exhaust valve.

Claims

The scope of the claims

[1] A gear for transmitting power from the crankshaft, a housing having a shaft through hole in the center, a case having a plurality of protrusions on the inside, and forming a hydraulic chamber between the shoes, A first rotating body having a cover that closes an opening on one end side of the case, and a plurality of vanes that are positioned between the shroud and partition the hydraulic chamber into an advance hydraulic chamber and a retard hydraulic chamber; A second rotating body that is rotatable in the first rotating body and is fixed to an intake or exhaust camshaft, and is disposed so as to close the openings on both sides of the case to which the second rotating body is assembled. In the valve timing adjusting device in which the cover and the housing are fixed integrally with the case,

A valve timing adjusting device, wherein the case and the cover are integrally joined by sintering.

[2] The valve timing adjusting device according to [1], wherein the case and the cover are made of different materials.

[3] The cover and the case having a plate thickness thinner than that of the wing and the wing are sintered and joined.

1. The valve timing adjusting device according to 1.