JP6868448B2 - Valve stem seal - Google Patents

Description

The present invention relates to a valve stem seal.

Conventionally, as shown in FIG. 9, the metal ring 52 and the rubber-like elastic body 55 adhered to the metal ring 52 are provided, and the rubber-like elastic body 55 causes the seal lip 56, the sub-seal lip 57, and the inside. A valve stem seal 51 in which the peripheral seal portion 58 is integrally molded is known.

The metal ring 52 integrally has an end surface portion 53 that holds the seal lip 56 and the sub-seal lip 57, and a tubular portion 54 that is inserted into the outer peripheral side of the valve stem guide 61, and has an inner peripheral surface of the tubular portion 54. Is provided with an inner peripheral seal portion 58.

The inner diameter of the tubular portion 54 is set larger than the outer diameter of the valve stem guide 61, whereas the inner diameter of the inner peripheral seal portion 58 is set smaller than the outer diameter of the valve stem guide 61. ..

Therefore, when the tubular portion 54 is inserted into the outer peripheral side of the valve stem guide 61, the inner peripheral seal portion 58 is compressed in the radial direction to set a fitting allowance, and the fitting allowance causes the valve stem seal 51 to valve. It is fixedly attached to the outer peripheral side of the stem guide 61 and is prevented from coming off.

Further, a protrusion 59 may be integrally provided on a part of the inner peripheral surface of the inner peripheral seal portion 58. In this case, the protrusion 59 is also compressed in the radial direction, so that the fitting allowance increases and the retaining portion is prevented from coming off. The sex is enhanced.

Further, the inner peripheral seal portion 58 exerts a sealing function by being compressed in the radial direction between the tubular portion 54 and the valve stem guide 61, that is, from between the tubular portion 54 and the valve stem guide 61. It exerts a sealing function so that pressure (oil) does not leak.

Japanese Unexamined Patent Publication No. 2009-264415 Japanese Unexamined Patent Publication No. 2004-19852 Japanese Unexamined Patent Publication No. 2010-242823

However, the valve stem seal 51 has room for improvement in the following points.

That is, in recent years, the output of vehicle engines tends to increase, and along with this, a larger pressure (back pressure) P ₀ acts on the valve stem seal 51 attached to the valve stem guide 61. .. Therefore, it is required to further increase the fitting allowance so that the valve stem seal 51 does not fall off from the valve stem guide 61 even when such a large pressure P _{0 acts, and further enhance the retaining property.}

In view of the above points, it is an object of the present invention to further improve the preventive property of the valve stem seal with respect to the valve stem guide.

A valve having a metal ring fitted to a metal valve stem guide and a rubber-like elastic body integrally formed with a seal lip that is bridge-bonded to the metal ring and slidably contacts the outer peripheral surface of the valve stem. In the stem seal, the metal ring is provided at an annular end face portion that holds the seal lip and from the inner peripheral end portion of the end face portion toward one axial direction, and is inserted into the inner peripheral side of the valve stem guide. It is a metal annular member integrally having an inner cylinder portion and an outer cylinder portion provided in one axial direction from the outer peripheral end portion of the end face portion and inserted into the outer peripheral side of the valve stem guide. One of the cylinder portion and the outer cylinder portion forms a metal fitting portion in which metals are directly fitted to the valve stem guide, and one of the inner cylinder portion and the outer cylinder portion is bridged. through a glued the rubber-like elastic material forming the rubber fitting part for fitting engagement with the valve stem guide.

Valves stem guide further can increase the Hamagodai of the valve stem seal to be possible to further improve the retaining of the valve stem seal for a valve stem guide.

Half-cut sectional view of the valve stem seal according to the first embodiment Half-cut cross-sectional view showing the mounted state of the valve stem seal Half-cut sectional view of the valve stem seal according to the second embodiment Half-cut cross-sectional view showing the mounted state of the valve stem seal Half-cut sectional view of the valve stem seal according to the third embodiment A view in FIG. 5 Half-cut cross-sectional view showing the mounting process of the valve stem seal Half-cut cross-sectional view showing the mounted state of the valve stem seal Cross-sectional view showing the mounting state of the valve stem seal according to the background technology

First Embodiment ...
As shown in FIGS. 1 and 2, the valve stem seal 11 has a metal ring 21 and a rubber-like elastic body 31 adhered (bridge-bonded) to the metal ring 21, and is formed by the rubber-like elastic body 31. A seal lip (main seal lip) 32 that slidably contacts the outer peripheral surface of the valve stem 71, and a sub that slidably contacts the outer peripheral surface of the valve stem 71 on the back side (lower side in the figure) of the seal lip 32. The seal lip 33, the end face covering portion 34 that covers the lip side end surface (upper end face in the figure) of the metal ring 21, the outer peripheral covering portion 35 that covers the outer peripheral surface of the metal ring 21, and the anti-lip side end of the metal ring 21. The tip covering portion 36 that covers the portion (lower end portion in the figure), the inner peripheral sealing portion 37 that covers the inner peripheral surface of the metal ring 21 and contacts the outer peripheral surface of the valve stem guide 61, and the inner peripheral sealing portion. An annular protrusion 38 provided on the inner peripheral surface of the 37 is integrally formed. The seal lip 32 has two lip sliding ends 32a and 32b on the inner peripheral portion thereof, and a coil spring 12 is fitted on the outer peripheral portion of the seal lip 32.

The metal ring 21 has an annular end face portion 22 that holds the seal lip 32 and the sub-seal lip 33, and is directed from the inner peripheral end portion of the end face portion 22 toward one axial direction (anti-lip side, downward in the figure). The inner cylinder portion 23 is integrally provided, and the outer cylinder portion 24 is integrally provided from the outer peripheral end portion of the end surface portion 22 in the same axial direction, and the outer peripheral surface, the anti-lip side end portion, and the outer cylinder portion 24 are integrally provided. The outer peripheral covering portion 35, the tip covering portion 36, and the inner peripheral sealing portion 37 are adhered to the inner peripheral surface. On the other hand, the rubber-like elastic body is not adhered to the surface of the inner cylinder portion 23, and in particular, the rubber-like elastic body is not adhered to the outer peripheral surface of the inner cylinder portion 23.

_{The outer diameter dimension d 1} of the inner cylinder portion 23 is set to be larger than _{the inner diameter dimension d 2} of the annular step portion 62 provided at the lip side end portion (upper end portion in the figure) of the valve stem guide 61 _{(d 1} >. d ₂ ). The valve stem guide 61 is made of metal. Therefore, when the inner cylinder portion 23 is inserted into the inner peripheral side of the annular step portion 62, the metals are fitted together and a fitting allowance of a predetermined size is set. Therefore, the inner cylinder portion 23 is a metal fitting portion 25 in which the metal is directly fitted to the metal.

On the other hand, the inner diameter dimension d ₃ of the outer cylinder portion 24 is set to be larger than _{the outer diameter dimension d 4} of the valve stem guide 61 _{(d 3} > d ₄ ), and the inner diameter dimension d ₅ of the inner peripheral seal portion 37 is the valve stem guide. It is set smaller than the outer diameter dimension d _{4 of 61 (d 5} <d ₄ ). Therefore, when the outer cylinder portion 24 is inserted into the outer peripheral side of the valve stem guide 61, the inner peripheral seal portion 37 is compressed in the radial direction, and the outer cylinder portion 24 is fitted to the valve stem guide 61 via the inner peripheral seal portion 37. , And a fitting allowance of a predetermined size is set. Therefore, the outer cylinder portion 24 is a rubber fitting portion 26 in which the metal is fitted to the metal via a rubber-like elastic body.

As described above, the valve stem guide 61 is provided with an annular step portion 62 for inserting and fitting the inner cylinder portion 23 at the inner peripheral portion of the lip side end portion of the valve stem guide 61. Further, an annular recess 63 for fitting the protrusion 38 provided on the inner peripheral surface of the inner peripheral seal portion 37 and engaging in the pull-out direction (upward in the figure) is provided on the outer peripheral surface of the valve stem guide 61. ing.

In the valve stem seal 11 having the above configuration, the inner cylinder portion 23 is provided on the metal ring 21, and the inner cylinder portion 23 is a metal fitting portion 25 that directly fits the valve stem guide 61, and is made of metal. An outer cylinder portion 24 is provided on the ring 21, and the outer cylinder portion 24 is a rubber fitting portion 26 that fits into the valve stem guide 61 via an inner peripheral seal portion 37 made of a rubber-like elastic body. Since both the metal fitting portion 25 and the rubber fitting portion 26 are provided on the valve stem guide 61 to sandwich the valve stem guide 61 from the inner diameter side and the outer diameter side, the valve with respect to the valve stem guide 61 is compared with the case where either one is provided. It is possible to increase the fitting allowance of the stem seal 11. Therefore, the preventive property of the valve stem seal 11 with respect to the valve stem guide 61 can be improved.

Further, since the inner peripheral seal portion 37 attached to the inner peripheral surface of the outer cylinder portion 24 is in close contact with the outer peripheral surface of the valve stem guide 61 in a state of being compressed in the radial direction, the inner circumference made of a rubber-like elastic body is formed. The seal portion 37 exerts a sealing function. Therefore, it is possible to prevent pressure (oil) from leaking between the metal ring 21 and the valve stem guide 61.

Second embodiment ...
In the first embodiment, the inner cylinder portion 23 of the metal ring 21 is the metal fitting portion 25 and the outer cylinder portion 24 is the rubber fitting portion 26. On the contrary, the outer cylinder portion 24 of the metal ring 21 is used. May be a metal fitting portion 25 and the inner cylinder portion 23 may be a rubber fitting portion 26. Hereinafter, this form will be described.

As shown in FIGS. 3 and 4, the valve stem seal 11 has a metal ring 21 and a rubber-like elastic body 31 adhered (bridge-bonded) to the metal ring 21, and is formed by the rubber-like elastic body 31. A seal lip (main seal lip) 32 that slidably contacts the outer peripheral surface of the valve stem 71, and a sub that slidably contacts the outer peripheral surface of the valve stem 71 on the back side (lower side in the figure) of the seal lip 32. The seal lip 33, the inner peripheral covering portion 39 that covers the inner peripheral surface of the inner cylinder portion 23 of the metal ring 21, and the tip coating that covers the anti-lip side end portion (lower end portion in the figure) of the inner cylinder portion 23. The outer peripheral sealing portion 41 that covers the outer peripheral surface of the inner cylinder portion 23 and is in contact with the inner peripheral surface of the annular step portion 62 of the valve stem guide 61 is integrally formed with the portion 40. The seal lip 32 has two lip sliding ends 32a and 32b on the inner peripheral portion thereof, and a coil spring 12 is fitted on the outer peripheral portion of the seal lip 32.

The metal ring 21 has an annular end face portion 22 that holds the seal lip 32 and the sub-seal lip 33, and is directed from the inner peripheral end portion of the end face portion 22 toward one axial direction (anti-lip side, downward in the figure). The inner cylinder portion 23 is integrally provided, and the outer cylinder portion 24 is integrally provided from the outer peripheral end portion of the end surface portion 22 in the same axial direction as well. The inner peripheral covering portion 39, the tip covering portion 40, and the outer peripheral sealing portion 41 described above are adhered to the outer peripheral surface. On the other hand, the rubber-like elastic body is not adhered to the surface of the outer cylinder portion 24, and in particular, the rubber-like elastic body is not adhered to the inner peripheral surface of the outer cylinder portion 24.

The inner diameter dimension d ₃ of the outer cylinder portion 24 is set smaller than _{the outer diameter dimension d 4} of the valve stem guide 61 _{(d 3} <d ₄ ). The valve stem guide 61 is made of metal. Therefore, when the outer cylinder portion 24 is inserted into the outer peripheral side of the valve stem guide 61, the metals are fitted together and a fitting allowance of a predetermined size is set. Therefore, the outer cylinder portion 24 is a metal fitting portion 25 in which the metal is directly fitted to the metal.

On the other hand, the outer diameter dimension d ₁ of the inner cylinder portion 23 is set smaller than _{the inner diameter dimension d 2} of the annular step portion 62 provided at the lip side end portion (upper end portion in the figure) of the valve stem guide 61 _{(d 1} <. d _{2 ) The outer diameter dimension d 6} of the outer peripheral seal portion 41 is set to be larger than _{the inner diameter dimension d 2} of the annular step portion 62 _{(d 6} > d ₂ ). Therefore, when the inner cylinder portion 23 is inserted into the inner peripheral side of the annular step portion 62, the outer peripheral seal portion 41 is compressed in the radial direction, and the inner cylinder portion 23 fits into the inner peripheral surface of the annular step portion 62 via the outer peripheral seal portion 41. A fitting allowance of a predetermined size is set. Therefore, the inner cylinder portion 23 is a rubber fitting portion 26 in which the metal is fitted to the metal via a rubber-like elastic body.

As described above, the valve stem guide 61 is provided with an annular step portion 62 for inserting and fitting the inner cylinder portion 23 at the inner peripheral portion of the lip side end portion of the valve stem guide 61.

In the valve stem seal 11 having the above configuration, the outer cylinder portion 24 is provided on the metal ring 21, and the outer cylinder portion 24 is a metal fitting portion 25 that directly fits the valve stem guide 61, and is made of metal. An inner cylinder portion 23 is provided on the ring 21, and the inner cylinder portion 23 is a rubber fitting portion 26 that fits into the valve stem guide 61 via an outer peripheral seal portion 41 made of a rubber-like elastic body. Since both the metal fitting portion 25 and the rubber fitting portion 26 are provided to sandwich the valve stem guide 61 from the inner diameter side and the outer diameter side, the valve stem with respect to the valve stem guide 61 is compared with the case where either one is provided. It is possible to increase the fitting allowance of the seal 11. Therefore, it is possible to improve the preventive property of the valve stem seal 11 with respect to the valve stem guide 61.

Further, since the outer peripheral seal portion 41 adhered to the outer peripheral surface of the inner cylinder portion 23 is in close contact with the inner peripheral surface of the annular step portion 62 in a state of being compressed in the radial direction, the outer peripheral seal portion made of a rubber-like elastic body is formed. 41 exerts a sealing function. Therefore, it is possible to prevent pressure (oil) from leaking between the metal ring 21 and the valve stem guide 61.

Third Embodiment ...
In the first embodiment, the valve stem seal 11 is prevented from coming off by using the inner cylinder portion 23 of the metal ring 21 as the metal fitting portion 25, but the inner cylinder portion 23 has a claw-shaped engaging portion. It is conceivable to further improve the retaining property by providing the claw-shaped engaging portion and engaging the claw-shaped engaging portion with the valve stem guide 61. Hereinafter, this form will be described.

That is, as shown in FIGS. 5 and 6, the inner cylinder portion 23 provided on the metal ring 21 of the valve stem seal 11 has a tapered tubular shape in which the diameter gradually increases from the root portion to the tip portion thereof, and the taper is formed. A claw-shaped engaging portion 27 is provided radially outward from the tip end portion of the tubular inner tubular portion 23 and diagonally toward the end face portion 22 side.

On the other hand, as shown in FIGS. 7 and 8, a groove-shaped engaging portion 64 is provided on the inner peripheral surface of the annular step portion 62 of the valve stem guide 61, and the groove-shaped engaging portion 64 is claw-shaped. The disengagement prevention property is further improved by engaging the engaging portion 27 in the disengagement direction (upward in the figure).

Further, according to the configuration in which the claw-shaped engaging portion 27 is engaged with the groove-shaped engaging portion 64 in this way, as shown in FIG. 7, the claw-shaped engaging portion 27 is engaged with the end surface portion of the valve stem guide 61. When a press-fitting load P is applied from the seal lip 32 side (upper side in the figure) in the state of being in contact with each other, the claw-shaped engaging portion 27 is elastic so as to reduce the radial dimension along the inner peripheral surface of the annular step portion 62. When it is deformed and the claw-shaped engaging portion 27 reaches the groove-shaped engaging portion 64 as shown in FIG. 8, it elastically returns and engages with the groove-shaped engaging portion 64. Therefore, it is possible to provide a structure in which the claw-shaped engaging portion 27 can be engaged with the groove-shaped engaging portion 64 with a small press-fitting load P, and the valve stem seal 11 does not easily come off from the valve stem guide 61.

In order to facilitate elastic deformation of the claw-shaped engaging portion 27 so as to reduce the diameter dimension along the inner peripheral surface of the annular step portion 62, the claw-shaped engaging portion 27 is placed on the circumference. It is preferable to divide it into a plurality of parts. From this point of view, in the embodiment, as shown in FIG. 6, the claw-shaped engaging portions 27 are divided into a plurality of (for example, 12 equal parts) on the circumference, and slits 28 are formed between the engaging portions 27 adjacent to each other. Is provided.

The other configurations and effects according to the third embodiment are the same as those of the first embodiment. Therefore, the description will be omitted by assigning the same reference numerals to the drawings.

11 Valve stem seal 12 Coil spring 21 Metal ring 22 End face part 23 Inner cylinder part 24 Outer cylinder part 25 Metal fitting part 26 Rubber fitting part 27 Claw-shaped engaging part 28 Slit 31 Rubber-like elastic body 32 Seal lip 33 Sub-seal Lip 34, 35, 36, 39, 40 Coating part 37 Inner circumference seal part 38 Protrusion part 41 Outer circumference seal part 61 Valve stem guide 62 Ring step part 63 Recession 64 Groove-shaped engaging part 71 Valve stem

Claims (2)

A metal ring fitted to the metal of the valve stem guide,
A rubber-like elastic body that is cross-linked and adhered to the metal ring and integrally forms a seal lip that slidably contacts the outer peripheral surface of the valve stem.
In the valve stem seal with
The metal ring is
An annular end face that holds the seal lip and
An inner cylinder portion provided from the inner peripheral end portion of the end face portion toward one axial direction and inserted into the inner peripheral side of the valve stem guide.
An outer cylinder portion provided from the outer peripheral end portion of the end face portion toward one axial direction and inserted into the outer peripheral side of the valve stem guide .
It is a metal annular member that integrally has
One of the inner cylinder portion and the outer cylinder portion forms a metal fitting portion in which metals are directly fitted to the valve stem guide.
And the other of the inner cylinder portion and the outer cylindrical portion forms a rubber fitting part for fitting engagement with the valve stem guide through the rubber-like elastic body that is crosslinked adhesive,
The valve stem seal is characterized by that. In the valve stem seal according to claim 1,
The inner cylinder portion forms the metal fitting portion, and the outer cylinder portion forms the rubber fitting portion.
A valve stem seal characterized in that a claw-shaped engaging portion that engages with a groove-shaped engaging portion provided on the valve stem guide is provided on the inner cylinder portion.

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