JP2009215881A - Valve timing adjustment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing adjustment device capable of eliminating portions in which cutting is required, and also improving the flexibility of manufacturing. <P>SOLUTION: This valve timing adjustment device comprises 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 at 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 pivotal in the first rotating body 1, and fixed to an intake or exhaust camshaft. The cover 4 and the housing 5 that are arranged so as to close openings at both sides of the case 3 to which the second rotating body 2 is assembled are integrally fixed to the case 3. The case 3 and the housing 4 are integrally joined to each other by sintering. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a valve timing adjusting device for controlling 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).

  The valve timing adjusting 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 protruding shoes on the inside and forming a hydraulic chamber between the shoes, and an opening of the case Rotate the crankshaft together with the cover cover.

  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 can be rotated by a predetermined angle within the assembled first rotating body. 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. .

  Here, the first rotating body in the conventional valve timing adjusting device is arranged so that the cylindrical case with both axial ends open is sandwiched between the cover and the housing, and the cover, the case, and the housing are integrally fastened and fixed by bolts. The structure is common. In this case, depending on the bolt fastening location, the outer peripheral end 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.

  In order to reduce the warping of the cover as described above, it is conceivable to increase the number of fastening bolts or to increase the thickness of the cover to such an extent that warpage does not occur. Is also disadvantageous. In addition, it is conceivable to use a high-hardness material for the cover, but in the case of fastening with bolts, it may be difficult to reduce oil leakage due to performance and mounting restrictions.

  As a solution to such a problem, for example, there is a valve timing adjusting device disclosed in Patent Document 1. 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 a clearance between the cover and the case and preventing oil leakage.

Japanese Patent Laid-Open No. 11-117717

  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 formed 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 component 100 in which a case and a cover are integrated is manufactured by molding using aluminum die casting or the like, it is necessary to form a tapered portion 100a for removing the mold from the molded product.

  For this reason, in order to incorporate the component 100 after the integral molding into the valve timing adjusting device, it is necessary to perform a cutting process to remove all the taper portion 100a, and there is a problem that the processing cost is high. In the case of integral molding, since the cover and the case are inevitably made of the same material, the degree of freedom in manufacturing is limited.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a valve timing adjusting device that can reduce a portion that requires cutting and can improve the degree of manufacturing freedom. To do.

  A valve timing adjusting device according to the present invention includes a housing for transmitting power from a crankshaft, a housing having a shaft insertion hole in the center, and a plurality of protruding shoes on the inside, and forming a hydraulic chamber between the shoes. And 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 shoes and partition the hydraulic chamber into an advance hydraulic chamber and a retard hydraulic chamber, A cover and a housing, which are rotatable within the rotating body and are fixed to the intake or exhaust camshaft, and are arranged so as to close the openings on both sides of the case where the second rotating body is assembled. In the valve timing adjusting device fixed integrally with the case, the case and the cover are integrated by sintering.

  According to the present invention, since the case and the cover are integrated by sintering joining, there is an effect that oil leakage from the valve timing adjusting device can be drastically reduced. In addition, since the case and the cover can be formed separately, it is not necessary to form a die-cut taper when the case and the cover are integrally formed, and the cutting site can be greatly reduced. Furthermore, since it can join in a solid phase, the high dimensional accuracy of a sintered component 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.

Embodiment 1 FIG.
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 and shows a state in which the second rotating body is at the most advanced position with respect to the first rotating body.

  The valve timing adjusting apparatus according to the first embodiment includes a first rotating body 1 that rotates synchronously via a crankshaft and a chain of an engine (not shown), an intake or unillustrated intake that is provided in the first rotating body 1 and is not shown. And a second rotating body 2 integrally fixed to an end surface of an exhaust camshaft (hereinafter referred to as a camshaft).

  As shown in FIG. 2, the first rotating body 1 has a cylindrical shape with both ends in the axial direction opened, and a case 3 in which a plurality of shoes 3 a protruding inward of the cylindrical radial direction are formed. And 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. 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.

  The 2nd rotary body 2 has the boss | hub part 2a and the several vane 2b which protruded to the radial direction outer side from the outer peripheral part of the boss | hub part 2a. In the second rotating body 2, the camshaft is inserted into the center hole 5a of the housing 5 and the insertion hole 1a formed in the axial direction of the boss portion 2a communicating with the hole 5a, and the camshaft is not shown on the insertion side end face of the camshaft. The boss 2a is fastened by a center bolt (not shown) inserted from the hole 1b side through a washer. Thereby, the 2nd rotary body 2 and a camshaft are fixed integrally.

  The vane 2b includes an advance hydraulic chamber 7 that receives hydraulic pressure when the second rotary body 2 is rotated relative to the first rotary body 1 toward the advance side with respect to the plurality of inner spaces defined by the shoes 3a. The second rotating body 2 is partitioned into a retarded hydraulic chamber 8 that receives hydraulic pressure when the second rotating body 2 is rotated relative to the first rotating body 1 toward the retarded angle side.

  Each advance hydraulic chamber 7 communicates with an advance oil passage 9 for supplying and discharging hydraulic pressure, and each retard hydraulic chamber 8 is communicated with a retard oil passage 10 for supplying and discharging hydraulic pressure. In the vane 2b, a seal 11 for preventing oil leakage of the advance hydraulic chamber 7 and the retard hydraulic chamber 8 is inserted on the outer peripheral surface in contact with the inner peripheral surface of the case 3, and urged by the leaf spring 12 radially outward. Has been. Note that 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 a separate seal is provided. You may cope by providing a means.

  A storage hole 13 penetrating from the inside to the outside in the radial direction is formed in any shoe 3 a of the case 3. In the storage hole 13, there are provided a substantially cylindrical lock pin 14 that can reciprocate, a compression spring 15 that always urges the lock pin 14 radially inward, and a stopper 16 that locks one end of the compression spring 15. ing. The stopper 16 is integrated with the case 3 by a retaining pin 17 so that it does not fall out of the storage hole 13 due to the urging force of the compression spring 15. In addition, a communication hole 16 a is provided at the center of the stopper 16 with the outside.

  When the relative position of the second rotating body 2 with respect to the first rotating body 1 is at the most retarded position on the outer peripheral surface of the boss portion 2a, the lock pin 14 is advanced radially inward by the biasing force of the compression spring 15. A fitting hole 18 to be fitted is formed. 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 reciprocates within the storage hole. A movable lock pin may be provided, and the relative rotation of the rotor may be controlled by fitting the lock pin into a fitting hole provided in the sliding direction.

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 spring 15.
In the case of the advance operation, the 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 spring 15, and the fitting state with the fitting hole 18 is released. In the second rotating body 2 from which the lock pin 14 is released, the oil is supplied 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 path 10, it is relatively rotated toward the advance side.

  In the case of the retarded operation, oil is supplied into the retarded hydraulic chamber 8 through the retarded oil passage 10, and the oil in the advanced hydraulic chamber 7 is discharged through the advanced oil passage 9 to retard. Rotate relative to the side. Here, when the relative position of the second rotating body 2 with respect to the first rotating body 1 reaches the most retarded position, the lock pin 14 slides radially inward in the housing hole 13 by the urging force of the compression spring 15, Fit 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 arranged at a predetermined combination position, and heated and sintered at a temperature below the melting point of the case 3 and the cover 4 in a sintering furnace. At the same time, the solid phase is joined. In this sintered joining, diffusion (diffusion of metal molecules) occurs at the atomic level in the contact portion of the members to be joined, and a firm joining without defects can be realized.

  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, oil does not leak from the joint portion of the case 3 and the cover 4. In addition, since the case 3 and the cover 4 are separately formed and then sintered and joined, unlike the case where the case and the cover are integrally formed with aluminum die casting or the like, there is no need to provide a die-cut taper on the inner wall of the case 3, The cutting part can be greatly reduced. Moreover, since it can join in a solid phase, it can maintain a high dimensional accuracy compared with fusion joining.

  Further, in the case of sintering bonding, it is possible to join different materials. By utilizing this characteristic, it is also possible to use, for example, a general-purpose iron material that is not a high-strength material or a thin member of aluminum material. Moreover, you may make it sinter-join to the case 3 of a sintered component by using the member created by press molding of sheet metal as the cover 4. In this case, in the cover 4, it is easy to create a countersunk screw portion (a tapered hole portion into which the head of the bolt 6 in FIG. 1 fits) whose shape is not uniform in the axial direction of the first rotating body 1.

  As described above, according to the first embodiment, since the case 3 and the cover 4 are integrated by sintering joining, oil leakage from the valve timing adjusting device can be drastically reduced. Since the case 3 and the cover 4 can be formed separately, it is not necessary to form a die punch taper when integrally molded, and the cutting site can be greatly reduced. Moreover, since it can join in a solid phase, the high dimensional accuracy of a sintered component 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. For example, it is also possible to use a general-purpose iron material or a thin member of aluminum material that is not a high-strength material different from the case 3 only for the cover 4.

  In the first embodiment, the example in which the housing 5 is fastened with the bolt 6 inserted from the thin cover 4 side is shown. However, as shown in FIG. 4, the bolt inserted from the thick housing side. 6, the case 3 and the housing 5 may be fastened. In this case, the bolt insertion hole 6a formed in the shoe 3a needs to be a screw hole.

  In the first embodiment, the example in which the cover 4 and the case 3 having a thickness smaller than that of the housing 5 are integrated by sintering is shown. However, if the housing 5 is thinner than the cover 4, You may comprise so that between 3 and the housing 5 may be joined by sintering. In this configuration, the case 3 and the thin housing 5 can be made of different materials. For example, a general-purpose iron material or a thin aluminum material that is not a high-strength material is used as the thin member. Is also possible.

It is a figure which shows the internal structure of the valve timing adjustment apparatus by Embodiment 1 of this invention. It is sectional drawing in the AA line in FIG. 1 of the valve timing adjustment apparatus which has a 2nd rotary body in the most retarded angle position with respect to a 1st rotary body. It is sectional drawing in the AA line in FIG. 1 of the valve timing adjustment apparatus which has a 2nd rotary body in the most advanced angle position with respect to a 1st rotary body. It is a figure which shows the other structural example of the valve timing adjustment apparatus by Embodiment 1. FIG. It is a figure which shows the integrally molded component of the case and cover formed by the aluminum die casting etc.

Explanation of symbols

  1 1st rotating body, 1a insertion hole, 2nd rotating body, 2a boss, 2b vane, 3a shoe, 3 case, 4 cover, 5 housing, 6 bolt, 7 advance hydraulic chamber, 8 retard hydraulic chamber, 9 Lead oil passage, 10 retard oil passage, 11 seal, 12 leaf spring, 13 storage hole, 14 lock pin, 15 compression spring, 16 stopper, 17 retaining pin, 18 fitting hole, 19 release oil passage.

Claims (3)

A power transmission gear from the crankshaft and a housing having a shaft insertion hole in the center, a case having a plurality of protruding shoes on the inside, forming a hydraulic chamber between the shoes, and an opening on one end side of the case And a plurality of vanes that are positioned between the shoes and divide the hydraulic chamber into an advance hydraulic chamber and a retard hydraulic chamber, and rotate in the first rotary body. A second rotating body fixed to an intake or exhaust camshaft, and the cover and the housing arranged to close the openings on both sides of the case to which the second rotating body is assembled. In the valve timing adjustment device fixed integrally with the case,
The valve timing adjusting device, wherein the case and the cover are integrated by sintering.   2. The valve timing adjusting device according to claim 1, wherein the case and the cover are made of different materials.   3. The valve timing adjusting device according to claim 1, wherein the cover and the case having a thickness smaller than that of the housing are sintered and joined.

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