JP2007309215A - Guide structure for valve spring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a guide structure for a valve spring capable of surely guiding the valve spring. <P>SOLUTION: This guide structure for the valve spring is provided with a cylinder head 6, a valve 1 including a stem 10 provided on the cylinder head 6, a valve guide 5 put between the stem 10 and the cylinder head 6 and supporting the valve 1 in such a manner that the same can move in an axial direction, a stem seal 4 sealing a part between the valve guide 5 and the stem 10, and the valve spring 3 positioned in an outer circumference side of the stem 10 and energizing the valve 1. The valve spring 3 is guided by the stem seal 4. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a guide structure for a valve spring, and more particularly to a guide structure for a valve spring of an internal combustion engine mounted on a vehicle.

Conventional valve spring guide structures are disclosed in, for example, Japanese Patent Publication No. 8-6566 (Patent Document 1), Japanese Utility Model Publication No. 5-17364 (Patent Document 2), and Japanese Patent Application Laid-Open No. 2002-180810 (Patent Document 3). Has been.
Japanese Patent Publication No. 8-6566 No. 5-17364 JP 2002-180810 A

  In the conventional technology, when the retainer is assembled, the spring is mounted on the guide part of the spring seat, and even if the spring is guided to the valve spring seat, the spring runs on the guide part of the retainer due to variations, and the valve is normal. Did not work.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a guide structure capable of reliably guiding a valve spring.

  A guide structure for a valve spring according to the present invention includes a cylinder head, a valve provided on the cylinder head, having a stem, and a valve interposed between the stem and the cylinder head so as to be movable in the axial direction. A guide, a stem seal that seals between the valve guide and the stem, and a valve spring that is positioned on the outer peripheral side of the stem and biases the valve. The valve spring is guided by a stem seal.

  In the valve spring guide structure configured as described above, the valve spring is guided by the stem seal, so that the valve spring can be reliably guided as compared with the case where the valve spring is not guided by the stem seal.

  Preferably, the cylinder head is provided with a groove for receiving the valve spring, and the gap A between the inner peripheral surface of the valve spring and the outer peripheral surface of the stem seal is between the outer peripheral surface of the valve spring and the outer peripheral wall of the groove. It is smaller than the gap B.

  In this case, since the gap A between the inner periphery of the valve spring and the outer periphery of the stem seal is smaller than the gap B between the outer periphery of the valve spring and the outer wall of the groove, the valve spring is guided by the stem seal and rides on the outer wall side of the groove. Nothing will happen.

  Preferably, the cylinder head is provided with a groove for receiving the valve spring, and the gap A between the inner peripheral surface of the valve spring and the outer peripheral surface of the stem seal is between the inner peripheral surface of the valve spring and the inner peripheral wall of the groove. Is smaller than the gap C.

  In the valve spring guide structure thus configured, the gap A between the inner periphery of the valve spring and the outer periphery of the stem seal is smaller than the gap C between the inner periphery of the valve spring and the inner peripheral wall of the groove. Is guided by the stem seal, and the valve spring does not run on the inner peripheral side of the groove.

  More preferably, the retainer further includes a retainer that engages with the valve and abuts on the valve spring, and the retainer is located on the inner peripheral side of the flange portion and is thicker than the flange portion. The clearance A between the valve spring inner peripheral surface and the stem seal outer peripheral surface is smaller than the clearance D between the valve spring inner peripheral surface and the retainer guide outer peripheral surface.

  In the valve spring guide structure thus configured, the gap A between the valve spring inner periphery and the stem seal outer peripheral surface is smaller than the gap D between the valve spring inner peripheral surface and the retainer guide outer peripheral surface. The valve spring is guided by the retainer guide, and it is possible to prevent the valve spring from riding on the retainer guide which is a thick portion of the retainer.

  Preferably, a valve seat is provided on the portion of the cylinder head that contacts the valve spring.

  According to the present invention, it is possible to provide a valve spring guide structure capable of guiding the valve spring more reliably.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
1 is a cross-sectional view of a cylinder head having a valve spring guide structure according to Embodiment 1 of the present invention. Referring to FIG. 1, the valve spring guide structure according to the first embodiment of the present invention has valve 1 positioned in cylinder head 6. An exhaust passage 16 is provided in the cylinder head 6, and the exhaust passage 16 continues to the combustion chamber 17. Combustion gas (exhaust gas) generated in the combustion chamber 17 is discharged to the outside through the exhaust passage 16.

  The valve 1 includes a shaft-like stem 10 and an umbrella portion 19 attached to the end of the stem 10. When the umbrella part 19 faces the combustion chamber 17 and the umbrella part 19 seals the gas in the combustion chamber 17, it is possible to prevent the gas in the combustion chamber 17 from leaking to the outside.

  The valve 1 can reciprocate along the direction in which the stem 10 extends. Thereby, the umbrella part 19 of the valve 1 opens and closes, and the gas in the combustion chamber 17 can be released to the outside, or the gas can be confined in the combustion chamber 17.

  The lock member 205 is fitted into the groove 18 provided at the upper end portion of the stem 10, and the retainer 2 is engaged with the lock member 205. The retainer 2 is a member for transmitting the force of the valve spring 3 to the valve 1 and has a disk shape and increases in thickness as it approaches the center. The end portion of the stem 10 of the valve 1 is pressed by receiving a force from a cam or a rocker arm. Thereby, the valve 1 moves in the valve opening direction. A force in the opposite direction to this movement is transmitted from the valve spring 3 to the valve 1 via the retainer 2. The retainer 2 includes a retainer guide 202 positioned at the center portion and a flange portion 201 positioned at the outer peripheral portion of the retainer guide 202. The retainer guide 202 is a thick portion and engages with the lock member 205. An outer peripheral surface 203 of the retainer guide 202 exists between the retainer guide 202 and the flange portion 201, and the outer peripheral surface 203 forms a step. Further, the lower surface 204 of the retainer guide 202 faces the cylinder head 6. The flange portion 201 is in contact with the valve spring 3 and receives a force from the valve spring 3.

  The valve spring 3 is a coil spring, and the pitch thereof may be constant and may be an uneven spring that is not constant. One end of the valve spring 3 is in contact with the retainer 2 and the other end is in contact with the cylinder head 6. The valve spring 3 has a cylindrical shape, and an inner peripheral surface 31 thereof faces the stem 10, and an outer peripheral surface 32 is positioned so as to face the inner peripheral surface 31. A groove 63 for positioning the valve spring 3 is provided in the cylinder head 6. The groove 63 is defined by the inner peripheral wall 13 and the outer peripheral wall 11, and the valve seat 12 is provided between the inner peripheral wall 13 and the outer peripheral wall 11. The valve seat 12 may be provided separately from the cylinder head 6, or the valve seat 12 may be configured by subjecting the groove 63 to surface treatment and curing.

  The stem 10 is guided by a valve guide 5. The valve guide 5 abuts on the stem 10, and the stem 10 contacts and slides on the valve guide 5. The valve guide 5 is fixed to the cylinder head 6 and has a function of reducing the frictional resistance due to the contact of the stem 10.

  The stem seal 4 serves to prevent exhaust gas from leaking between the valve guide 5 and the stem 10. That is, the interface between the valve guide 5 and the stem 10 reaches the exhaust passage 16, and the exhaust pressure is applied between the valve guide 5 and the stem 10. On the basis of the exhaust pressure, the exhaust gas may pass through the cylinder head 6 between the stem 10 and the valve guide 5 in some cases. When such exhaust gas is discharged out of the cylinder head 6, there is a concern about deterioration of environmental performance. Therefore, the stem seal 4 is provided to prevent the exhaust gas from leaking between the valve guide 5 and the stem 10. The outer peripheral surface 41 of the stem seal 4 faces the inner peripheral surface 31 of the valve spring 3. The retainer guide 202 of the retainer 2 is engaged with the groove 18 of the stem 10.

  The cylinder head 6 has an inner peripheral surface 61 positioned on the inner side of the valve spring 3 and an outer peripheral surface 62 positioned on the outer side of the valve spring 3.

  FIG. 2 is a cross-sectional view of the cylinder head in a valve open state. Referring to FIG. 2, when a cam (not shown) pushes the stem 10, this force is applied to the entire valve 1 and the umbrella portion 19 moves downward. Thereby, the combustion chamber 17 and the exhaust passage 16 communicate with each other, and the combustion chamber gas in the combustion chamber 17 is discharged.

  In this embodiment, the structure according to the present invention is provided in the exhaust side valve 1, but the present invention may be applied to the intake side valve.

  Furthermore, the engine as the internal combustion engine may be either a gasoline engine or a diesel engine, and a turbocharger, a supercharger, or the like may be attached to these engines.

  Furthermore, various types of engines such as a series type, a V type, a W type, and a horizontally opposed type can be adopted as the shape of the engine.

  Also, regarding the cooling method of the engine, various cooling methods of air cooling type and water cooling type can be adopted. Furthermore, it is preferable that each moving component such as the valve 1 and the valve spring 3 provided on the cylinder head 6 is lubricated with lubricating oil.

  FIG. 3 is a cross-sectional view showing details of each member in FIG. Referring to FIG. 3, the guide structure of the valve spring is provided in cylinder head 6, cylinder head 6, valve 1 having stem 10, and valve 1 is pivoted between stem 10 and cylinder head 6. A valve guide 5 that is movably supported in a direction, a stem seal 4 that seals between the valve guide 5 and the stem 10, and a valve spring 3 that is positioned on the outer peripheral side of the stem 10 and biases the valve 1. . The valve spring 3 is guided by a stem seal 4.

  The cylinder head 6 is provided with a groove 63 for receiving the valve spring 3. The clearance A between the inner peripheral surface 31 of the valve spring 3 and the outer peripheral surface 41 of the stem seal 4 is smaller than the clearance B between the outer peripheral surface 32 of the valve spring 3 and the outer peripheral wall 11 of the groove 63.

  The clearance A is smaller than the clearance C between the inner peripheral surface 31 of the valve spring 3 and the inner peripheral wall 13 of the groove 63.

  The guide structure of the valve spring 3 further includes a retainer 2 that engages with the valve 1 and contacts the valve spring 3. The retainer 2 includes a flange portion 201 that is in contact with the valve spring 3 and a retainer guide 202 that is located on the inner peripheral side of the flange portion 201 and is thicker than the flange portion 201. The clearance A is smaller than the clearance D between the inner peripheral surface 31 of the valve spring 3 and the outer peripheral surface 203 of the retainer guide 202.

  A valve seat 12 is provided at a portion of the cylinder head 6 that contacts the valve spring 3.

  That is, the present invention employs a structure in which the gap A is made smaller than the gap B and the valve spring 3 is guided by the stem seal 4.

  Further, since the gap A is smaller than the gap C, the stem seal 4 guides the valve spring 3. Therefore, the valve spring 3 is prevented from riding on the inner peripheral surface 61 during assembly.

  Further, with respect to the retainer 2, since the gap A is made smaller than the gap D, the stem seal 4 guides the valve spring 3. Therefore, it is possible to prevent the valve spring 3 from climbing onto the surface 204 of the retainer 2 during assembly.

  When the valve seat 12 is provided integrally with the cylinder head 6, the valve seat 12 may be configured by performing a surface treatment (laser quenching or the like).

  FIG. 4 is a cross-sectional view of the cylinder head shown for explaining the assembly process. Referring to FIG. 4, when assembling, first, valve guide 5, valve 1 and stem seal 4 are assembled to cylinder head 6. In this state, the valve spring 3 is fitted to the stem 10. At this time, as shown in FIG. 3, since the gap A between the outer peripheral surface 41 of the stem seal 4 and the inner peripheral surface 31 of the valve spring 3 is adjusted to be smaller than the gap B and the gap C, the stem The valve spring 3 is guided by the outer peripheral surface 41 of the seal 4, and the valve spring 3 can be prevented from coming into contact with the inner peripheral surface 61 and the outer peripheral surface 62 away from the groove 63. Therefore, it is possible to prevent the valve spring 3 from riding on the inner peripheral surface 61 and the outer peripheral surface 62, and to position the valve spring 3 with certainty.

  Further, after the valve spring 3 is fitted into the groove 63, the retainer 2 is fitted into the stem 10. At this time, since the gap A is smaller than the gap D, even if the valve spring 3 moves in the lateral direction by the gap A, the valve spring 3 does not run up to the retainer guide 202 side. As a result, reliable assembly is possible.

  With the valve spring guide structure according to the first embodiment of the present invention configured as described above, the valve spring can be reliably guided.

(Embodiment 2)
FIG. 5 is a cross-sectional view of a cylinder head having a guide structure for a valve spring according to a second embodiment of the present invention. Referring to FIG. 5, in the cylinder head according to the second embodiment of the present invention, there is no outer peripheral wall 11 located on the outer peripheral side of valve spring 3. Therefore, the gap B as shown in FIG. 3 does not exist and the gap C exists. The gap A is smaller than the gap C.

  The valve spring guide structure according to the second embodiment configured as described above has the same effect as the valve spring guide structure according to the first embodiment.

(Embodiment 3)
6 is a cross-sectional view of a cylinder head having a valve spring guide structure according to a third embodiment of the present invention. Referring to FIG. 6, in the valve spring guide structure according to the third embodiment of the present invention, there is no inner peripheral wall 13 of groove 63 as shown in FIG. Even the guide structure for the valve spring according to the third embodiment configured as described above can achieve the same effects as the guide structure for the valve spring according to the first embodiment.

(Embodiment 4)
FIG. 7 is a cross-sectional view of a cylinder head having a valve spring guide structure according to a fourth embodiment of the present invention. Referring to FIG. 7, in the valve spring guide structure according to the fourth embodiment of the present invention, neither cylinder wall 6 nor inner wall 13 and outer wall 11 are present, and groove 63 is not present. Thus, the valve spring guide structure according to the first embodiment is different.

  The valve spring guide structure according to the fourth embodiment configured as described above has the same effect as the valve spring guide structure according to the first embodiment.

(Embodiment 5)
FIG. 8 is a cross-sectional view of a cylinder head having a valve spring guide structure according to a fifth embodiment of the present invention. Referring to FIG. 8, in the valve spring guide structure according to the fifth embodiment of the present invention, in retainer 2, retainer guide 202 has a large outer diameter, and retainer guide 202 extends to the vicinity of valve spring 3. The valve spring guide structure according to the first embodiment is different in that there is almost no gap between the outer peripheral surface 203 of the retainer guide 202 and the valve spring 3. That is, when such a configuration is adopted, there is a possibility that the valve spring 3 will ride on the surface 204 of the retainer guide 202, but the valve 63 is not attached to the inner peripheral surface 61 and the outer peripheral surface 62 on the groove 63 side. It is possible to prevent the spring 3 from climbing up. In other words, in the present invention, if the gap A is smaller than any one of the gap B, the gap C, and the gap D, the valve spring 3 can be prevented from riding on another member at any part.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the cylinder head which has the guide structure of the valve spring according to Embodiment 1 of this invention. It is sectional drawing of the cylinder head of a valve opening state. It is sectional drawing which shows the detail of each member in FIG. It is sectional drawing of the cylinder head shown in order to demonstrate an assembly process. It is sectional drawing of the cylinder head which has the guide structure of the valve spring according to Embodiment 2 of this invention. It is sectional drawing of the cylinder head which has the guide structure of the valve spring according to Embodiment 3 of this invention. It is sectional drawing of the cylinder head which has the guide structure of the valve spring according to Embodiment 4 of this invention. It is sectional drawing of the cylinder head which has the guide structure of the valve spring according to Embodiment 5 of this invention.

Explanation of symbols

  1 Valve, 2 Retainer, 3 Spring, 4 Stem seal, 5 Valve guide, 6 Cylinder head, 10 Stem, 11 Outer wall, 12 Valve seat, 13 Inner wall, 16 Exhaust passage, 17 Combustion chamber, 18 Groove, 19 Umbrella , 31 inner peripheral surface, 32 outer peripheral surface, 61, 62 surface, 201 flange portion, 202 retainer guide, 203 outer peripheral surface, 204 surface.

Claims (5)

A cylinder head;
A valve having a stem provided in the cylinder head;
A valve guide interposed between the stem and the cylinder head to support the valve so as to be movable in the axial direction;
A stem seal that seals between the valve guide and the stem;
A valve spring positioned on the outer peripheral side of the stem and biasing the valve;
A valve spring guide structure in which the valve spring is guided by the stem seal.   The cylinder head is provided with a groove for receiving the valve spring, and a gap A between the valve spring inner peripheral surface and the stem seal outer peripheral surface is formed between the valve spring outer peripheral surface and the outer peripheral wall of the groove. The guide structure of the valve spring according to claim 1, wherein the guide structure is smaller than the gap B therebetween.   The cylinder head is provided with a groove for receiving the valve spring, and the clearance A between the inner peripheral surface of the valve spring and the outer peripheral surface of the stem seal is the inner peripheral wall of the valve spring and the inner peripheral wall of the groove. The guide structure of the valve spring according to claim 1, wherein the guide structure is smaller than a gap C therebetween. The retainer further includes a retainer that engages the valve and abuts on the valve spring, and the retainer is positioned on the inner peripheral side of the flange portion and a flange portion that abuts on the valve spring, and is thicker than the flange portion. A retainer guide,
The guide structure of the valve spring according to claim 1, wherein a gap A between the inner periphery of the valve spring and the outer periphery of the stem seal is smaller than a gap D between the inner periphery of the valve spring and the outer periphery of the retainer guide.   The valve spring guide structure according to any one of claims 1 to 4, wherein a valve seat is provided on a portion of the cylinder head that contacts the valve spring.

Images