JP2009167819A - Valve timing variable device in internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the installation workability of a head cover to a cylinder head, in a device fastened to bearing cap bodies by a through-bolt 32 which is penetratingly inserted into the head cover 2 to the cylinder head and valve holder members from an upper surface in the head cover, by arranging the valve holder members 22 and 24 having hydraulic control valves 21 and 23 to hydraulic variable mechanisms, on an upper surface of the bearing cap bodies 9 and 10 for journaling camshafts 4 and 5 having the hydraulic variable mechanisms 14 and 15 on an upper surface of the cylinder head 1. <P>SOLUTION: The valve holder members 22 and 24 are installed in the head cover 2 so as not to cause fall-off and horizontal dislocation by an insertion member 36 inserted so as not to penetrate the head cover. On the other hand, a slip-out checking part 40 opposed at an interval S3 narrower than an insertion length dimension S1 in the insertion member is arranged to the insertion member on the cylinder head 1 side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for varying a valve timing in one or both of an intake valve and an exhaust valve in an internal combustion engine.

  In general, this type of valve timing varying device is provided with a hydraulic variable mechanism that operates to advance or retard the rotation of the camshaft relative to the rotation of the crankshaft in the power transmission portion from the crankshaft to the camshaft. The valve timing is changed by switching the hydraulic pressure to the hydraulic variable mechanism with a hydraulic control valve.

  In this case, in Patent Document 1 as a prior art, a hydraulic pressure supply source on the cylinder head side and an upper surface of a bearing cap body that supports an upper half of a cam shaft with respect to an intake valve or an exhaust valve are provided on the upper surface of the cylinder head. An oil passage communicating with the hydraulic variable mechanism in the camshaft is opened, and a valve control member having a hydraulic control valve and an oil passage to the hydraulic control valve is provided inside the head cover that covers the entire upper surface of the cylinder head. The lower surface of the bearing cap body is disposed in close contact with the upper surface of the bearing cap body, and the oil passage in the valve holder member communicates with the oil passage in the bearing cap body on the contact surface. And the valve holder member is inserted through from the upper surface side of the head cover. At belt, it proposes to the configuration in which fastened to the bearing cap bodies.

Further, in the above-mentioned Patent Document 1 as the prior art, the valve holder member falls from the head cover or shifts laterally during the assembly of the head cover to the cylinder head in the above-described configuration. The holder member is integrally provided with a boss portion that penetrates the head cover and protrudes to the upper surface, and a retaining part is attached to the portion of the boss portion that protrudes from the upper surface of the head cover by heat-sealing synthetic resin. It is proposed that the valve holder member is assembled in the head cover by being fixed.
Japanese Patent Application Laid-Open No. 2007-1000065

  However, when the structure for assembling the valve holder member into the head cover is a structure as in the prior art, the valve holder member cannot be disassembled or is extremely difficult, and the valve There is a problem that oil leakage may occur from a portion where the boss portion provided integrally with the holder member penetrates the head cover.

  This invention makes it a technical subject to provide the valve timing variable apparatus which eliminated these problems.

In order to achieve this technical problem, claim 1 of the present invention provides:
“A hydraulic pressure supply source on the cylinder head side and the cam shaft are provided on the upper surface of the bearing cap body that supports one of the cam shaft for the intake valve and the cam shaft for the exhaust valve on the upper surface of the cylinder head. A valve holder member that opens an oil passage to the hydraulic variable mechanism and has a hydraulic control valve for the hydraulic variable mechanism and an oil passage to the hydraulic control valve inside a head cover that covers the cylinder head upper surface The bottom surface of the valve cap member is disposed in close contact with the top surface of the bearing cap body, and the oil passages of the valve holder member communicate with the oil passages of the bearing cap body. Furthermore, the head cover and the valve holder member are inserted through from the upper surface side of the head cover. At belt, in the variable valve timing device which is formed by fastening to the bearing cap bodies,
The valve holder member is attached to the inside of the head cover so as not to fall off and to be laterally displaced by an insertion member that is detachably inserted so as not to penetrate the head cover. An omission prevention portion is provided to confront the insertion member at an interval narrower than the insertion length dimension. "
It is characterized by that.

Further, claim 2 in the present invention is
“In the first aspect of the present invention, the camshaft includes an intake valve camshaft and an exhaust valve camshaft, and the bearing cap body corresponds to an intake valve camshaft and an exhaust valve camshaft. The valve holder member is configured by integrating a valve holder member for the intake valve camshaft and a valve holder member for the exhaust valve camshaft, and the insertion member further includes the intake valve. Both the valve holder member for exhaust and the valve holder member for exhaust valve are attached so that they cannot be detached and laterally displaced at the same time. "
It is characterized by that.

Furthermore, claim 3 of the present invention provides
“In the first or second aspect of the invention, the removal prevention portion is a part attached to the cylinder head side.”
It is characterized by that.

In addition, claim 4 of the present invention provides
“In claim 2, the bearing cap body for the intake valve cam shaft and the bearing cap body for the exhaust valve cam shaft are located at portions of the cam shafts adjacent to the timing chain wound around the sprocket. A support bracket for a chain guide for the portion between the two sprockets of the timing chain is attached to a portion between them, and the stopper portion is the support guide for the chain guide.
It is characterized by that.

  According to the configuration of the first aspect, before the head cover is attached to the cylinder head with the through bolt, the valve holder member can be assembled in advance with the insertion member so that the head cover cannot be dropped and laterally displaced.

  This facilitates the work of assembling the head cover with respect to the cylinder head while aligning the valve holder member with the bearing cap body on the cylinder head side within the head cover, greatly increasing the number of steps and time required for this. In addition, the risk of damaging components such as the valve holder member during assembly can be reliably reduced.

  In this case, since the insertion member with respect to the valve holder member is configured to be detachably inserted from the inside of the head cover so as not to penetrate, the lubricating oil inside the head cover leaks outside the insertion member. In addition, the risk of oil leakage can be reliably eliminated.

  In addition, the insertion member with respect to the valve holder member has a removal prevention portion provided on the cylinder head side facing each other with an interval narrower than the insertion length dimension of the insertion member. Even if the member is loosened due to the vibration or the like, it can be reliably prevented from falling off, so that damage due to the dropout of the insertion member is not caused.

  According to the second aspect of the present invention, when the variable valve timing device is provided on both the intake valve camshaft and the exhaust valve camshaft, the insertion member is connected to the intake valve camshaft and the valve holder member and the intake valve camshaft. Since it can be shared with the valve holder member for the camshaft for the valve, there is an advantage that the structure can be simplified.

  Furthermore, according to the configuration of claim 3, it is possible to prevent the insertion member from coming off and dropping by using various parts (for example, a bearing cap body or an oil scattering prevention member) attached to the cylinder head side. , Providing the removal prevention part separately from the various parts has the advantage of avoiding the complexity of the structure and the increase in the number of parts.

  In particular, according to the fourth aspect of the present invention, there is an advantage that the support bracket for the chain guide provided in the conventional internal combustion engine can be used as it is for the slip-off preventing portion.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  In these drawings, reference numeral 1 denotes a cylinder head in the internal combustion engine, reference numeral 2 denotes a head cover that covers the upper surface of the cylinder head 1, and the head cover 2 is made of a light alloy such as synthetic resin or aluminum, A plurality of bolts 3 are detachably joined to the upper surface of the cylinder head 1.

  On the upper surface of the cylinder head 1, an intake valve cam shaft 4 and an exhaust valve cam shaft 5 are arranged in parallel to each other. Both the cam shafts 4 and 5 are disposed on the cylinder head 1 side. The lower half bearing portions 6, 7 provided integrally and the upper half bearing cap bodies 9, 10 fastened thereto by bolts 8 are rotatably supported.

  One end of each of the camshafts 4 and 5 is sprockets 12 and 13 around which a timing chain 11 is wound between a crankshaft (not shown), and the rotation of the camshafts 4 and 5 is the rotation of the crankshaft. Conventionally known hydraulic variable mechanisms 14 and 15 are provided which operate so as to advance or retard.

  The intake valve bearing cap body 9 and the exhaust valve bearing cap body 10 are formed as a single component such that they are integrally connected by a connecting portion 16 therebetween. The upper surfaces 9a and 10a of the cap bodies 9 and 10 are provided with two oil passages 17 and 18 from a hydraulic pressure supply source on the cylinder head 1 side, and two hydraulic variable mechanisms 14 and 15 for the camshafts 4 and 5 respectively. Oil passages 19a, 19b, 20a, and 20b are opened.

  A valve holder member 22 having an intake valve hydraulic control valve 21 is disposed on the upper surface 9a of the intake valve bearing cap body 9, while an upper surface 10a of the exhaust valve bearing cap body 10 is disposed on the upper surface 9a. , A valve holder member 24 having a hydraulic control valve 23 for the exhaust valve is disposed, and these valve holder members 22 and 24 are integrally connected via a connecting portion 25 therebetween. , Is composed of one part.

  The intake valve holder member 22 includes a lower surface 22a that is in close contact with an upper surface 9a of the intake valve bearing cap body 9 with a gasket 26, which will be described later, interposed therebetween, and three oil passages 27 to the hydraulic control valve 21. , 28a, 28b are formed so as to open in the lower surface 22a.

  The exhaust valve valve holder member 24 is provided with a lower surface 24a that is in close contact with an upper surface 10a of the exhaust valve bearing cap body 10 with a gasket 29 described later interposed therebetween, and three oil passages 30 to the hydraulic control valve 23. , 31a, 31b are formed to open to the lower surface 24a.

  The head cover 2 and the intake valve valve holder member 22 and the exhaust valve valve member 24 constituting one part are arranged on the upper surface of the head cover 2 with respect to each of the bearing cap bodies 9 and 10. They are fastened by through bolts 32 that pass through them from the side and are inserted so as to be screwed into the boss portions 9b, 10b provided integrally with the bearing cap bodies 9, 10, respectively. The oil passages 17, 19a, 19b that open to the upper surface 9a of the bearing cap body 9 communicate with the oil passages 27, 28a, 28b that open to the lower surface 22a of the intake valve valve holder member 22, respectively. Each oil passage 18, 20a, 20b that opens to the upper surface 10a of the bearing cap body 10 opens to the lower surface 24a of the valve holder member 24 for the exhaust valve. Yl passage 30,31A, is configured to communicate to 31b.

  As shown in FIG. 2, the hydraulic control valve 21 in the intake valve holder member 22 and the hydraulic control valve 23 in the exhaust valve holder member 24 have operating actuators 21a and 23 as shown in FIG. The bosses 2a and 2b provided integrally with the head cover 2 project outward.

  Further, the gasket 26 interposed between the upper surface 9a of the intake valve bearing cap body 9 and the lower surface 22a of the intake valve valve holder member 22, the upper surface 10a of the exhaust valve bearing cap body 10, and the above-mentioned As shown in FIG. 5, each of the gaskets 29 interposed between the lower surface 24a of the valve holder member 24 for the exhaust valve is appropriately based on a mesh body such as a mesh metal mesh. The structure other than the oil passage is covered with a soft elastic body such as rubber and serves as both a tightly joined surface seal and a hydraulic oil filter.

  In the sealing of the intimately joined surface, instead of using the gaskets 26 and 29, or in addition to the gaskets 26 and 29, the lower surfaces 22a and 24a of the valve holder members 22 and 24 or the bearing cap body 9 , 10 can be provided with O-rings surrounding the oil passages on the upper surfaces 9a, 10a.

  Furthermore, each through bolt 32 is provided with a ring body 33 for preventing and positioning the synthetic resin head cover 2 excessively, and a seal body 34 for preventing leakage of lubricating oil. Yes.

  Further, a through hole 35 is formed in a connecting portion 25 that is located between the intake valve valve holder member 22 and the exhaust valve valve holder member 24 and integrally connects them. One headed bolt 36, which is one embodiment as an insertion member in the present invention, is inserted into the upper portion 35 from the lower side so as not to penetrate the lower surface of the head cover 2. The intake valve valve holder member 22 and the exhaust valve valve holder member 24 are placed inside the head cover 2 by screwing and fastening to a fixed metal nut 38 in a boss portion 37 provided in The single headed bolt 36 is assembled so that it cannot be dropped off and cannot be displaced laterally.

  On the other hand, among the timing chains 11 wound around the crankshaft and the sprockets 12 and 13 of the camshafts 4 and 5, a chain guide 39 for the timing chain 11 is provided in the portion between the sprockets 12 and 13. The base end portion of the bracket 40 that supports the chain guide 39 is located between the intake valve bearing cap body 9 and the exhaust valve bearing cap body 10 and connects the two together. It is attached to the upper surface of 16 by fastening with a plurality of bolts 41.

  In this case, the thickness of the connecting portion 25 is set so that the base end portion of the chain guide bracket 40 is screwed to the nut 38 of the head bolt 36 with respect to the lower end of the head bolt 36. By facing each other with a gap dimension S3 that is narrower than the insertion length dimension S1 to which the dimension is added, a removal preventing portion for the head bolt 36 is formed.

  In this configuration, before the head cover 2 is attached to the cylinder head 1 with the through bolts 33, as shown in FIG. Thus, the head cover 2 can be assembled to the cylinder head 1 so that the valve cover members 22 and 24 in the head cover 2 are not attached to the bearing cap bodies 9 and 10 on the cylinder head 1 side. The operation of assembling while adjusting the position can be easily and accurately performed.

  In this case, since the bolt 36 with a head constituting the insertion member is detachably inserted from the inside of the head cover 2 so as not to penetrate the head cover 2, the lubricating oil inside the head cover 2 is prevented from being inserted into the head cover 2. There is no leakage outside the attachment bolt 36, and oil leakage can be reliably prevented.

  Moreover, the support bracket 40 of the chain guide 39 is opposed to the head bolt 36 constituting the insertion member with a gap dimension S3 narrower than the insertion length dimension S1 of the head bolt 36 as a removal prevention portion. As a result, the headed bolt 36 can be reliably prevented from falling off even if it is loosened by vibration or the like.

  By configuring the gap dimension S3 to be narrower than the screwing length dimension S2 of the headed bolt 36, the headed bolt 36 can be prevented from coming off from the nut 38 to which it is screwed.

  In the above-described embodiment, the support bracket 40 of the chain guide 39 is used as a removal prevention portion for the headed bolt 36 that is an insertion member. However, the present invention is not limited to this, and the cylinder head 1 side is used. In addition to the various parts attached for the purpose other than the slip-off prevention part, for example, the bearing cap bodies 9, 10 or the oil scattering prevention member can be used as the slip-off prevention part. It can be configured such that a dedicated removal prevention portion is provided on the head 1 side.

  In particular, when the support bracket 40 of the chain guide 39 is used as a slip-off prevention portion as in the above-described embodiment, there is an advantage that a conventional chain guide support bracket can be used.

  In addition, the insertion member is not limited to the headed bolt 36 as in the embodiment, but may be a push-in pin configuration, the intake valve valve holder member 22 and the exhaust valve. In the case where the valve holder member 24 for valves is not integrated with each other, an insertion member can be provided for each of them.

FIG. 3 is a cross-sectional front view of the main part of the internal combustion engine taken along the line II in FIG. 2. FIG. 2 is a sectional view taken along line II-II in FIG. 1. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a figure which shows the state decomposed | disassembled. It is a perspective view of a gasket. FIG. 6 is an enlarged sectional view taken along line VI-VI in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Head cover 4 Intake valve cam shaft 5 Exhaust valve cam shaft 9, 10 Bearing cap body 9a, 10a Upper surface of bearing cap body 11 Timing chain 12, 13 Sprocket 14, 15 Hydraulic variable mechanism 16 Connecting part 21, 23 Hydraulic control valve 22, 24 Valve holder member 22a, 24a Bottom surface of valve holder member 25 Connecting portion 26, 29 Gasket 32 Through bolt 36 Head bolt (insertion member)
40 Chain guide support bracket

Claims (4)

Provided on the upper surface of the bearing cap body that supports one of the cam shaft for the intake valve and the cam shaft for the exhaust valve on the upper surface of the cylinder head, on the hydraulic pressure supply source on the cylinder head side and on the cam shaft. A hydraulic control valve for the hydraulic variable mechanism and a valve holder member having an oil path to the hydraulic control valve are provided inside the head cover that covers the cylinder head upper surface. The bottom surface of the bearing cap body is arranged so as to be in close contact with the top surface of the bearing cap body, and each of the oil passages of the valve holder member communicates with the oil passages of the bearing cap body at the tight joint surface. Further, a through-bore is inserted through the head cover and the valve holder member from the upper surface side of the head cover. At DOO, the variable valve timing device which is formed by fastening to the bearing cap bodies,
The valve holder member is attached to the inside of the head cover so as not to fall off and to be laterally displaced by an insertion member that is detachably inserted so as not to penetrate the head cover. A valve timing varying device in an internal combustion engine, characterized in that a slip-off preventing portion that is opposed to the insertion member at a distance narrower than the insertion length dimension is provided.   2. The cam shaft according to claim 1, wherein the cam shaft comprises an intake valve cam shaft and an exhaust valve cam shaft, and the bearing cap body is a bearing cap body for the intake valve cam shaft and a bearing for the exhaust valve cam shaft. The valve holder member has a structure in which a valve holder member for the intake valve camshaft and a valve holder member for the exhaust valve camshaft are integrated, and the insertion member is for the intake valve. A variable valve timing apparatus for an internal combustion engine, characterized in that both the valve holder member and the exhaust valve valve holder member are attached at the same time so as not to be detached and laterally displaced.   3. The variable valve timing apparatus for an internal combustion engine according to claim 1 or 2, wherein the removal preventing portion is a component attached to the cylinder head side.   3. The bearing cap body for the intake valve cam shaft and the bearing cap body for the exhaust valve cam shaft are located at portions adjacent to the timing chain wound on the sprockets of the two cam shafts. A chain guide support bracket is attached to a portion between the sprockets of the timing chain, and the slip-off preventing portion is the chain guide support bracket. Valve timing variable device in the engine.

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