JP2002188416A - Valve-stem seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve stem seal which is simple in constitution, while the dimensional control at the time of manufacture is easy, and assembly is also easy. SOLUTION: This is for sealing between a valve stem 15 pushed through to a valve guide 13 and a sleeve-like valve guide 13, it is installed at one edge of valve guide 13, and in the valve stem seal it has a sealing material 10 slides to the periphery side of valve stem 15, to the valve guide side of a sealing material 10, the mating part wall surface 13a and have been formed on the edge side of the valve-guide 13, provides a washer 12 which is to be fixed in fitting part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve stem seal used for a valve mechanism for intake or exhaust of an engine of an automobile or the like.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view of a main part of a cylinder head of an engine mounted on an automobile or the like, and shows a valve mechanism used for intake or exhaust.

[0003] A sleeve-shaped valve guide 113 is attached to the cylinder head 114 such that one end thereof faces the port 118. And valve guide 1
13, a valve stem 11 which is a valve shaft of the valve 116 is provided.
5 is slidably inserted in the direction of the arrow in the figure.

The valve stem 115 is supported by a valve spring 117 while being urged in a direction in which the valve 116 closes. Then, according to a predetermined valve timing,
When a cam (not shown) presses the valve stem 115 toward the port side P, the valve 116 opens, and the port 11
8 and a cylinder (not shown) communicate with each other to perform intake or exhaust.

In order to ensure lubricity between the valve stem 115 serving as a reciprocating sliding portion and the valve guide 113, a lubricating oil supply means (not shown) is provided above the valve stem 115 (in the following description, the lubricating oil supply side). O) to form an oil film between the valve stem 115 and the valve guide 113.

At this time, if the amount of oil is too large,
8, oil leakage occurs, which causes pollution of exhaust gas and exhaust system, and undesirably increases oil consumption. Conversely, if the oil amount is too small, the valve stem 115 and the valve guide 113
Burn-in or the like occurs between the two.

Therefore, a valve stem seal 100 is attached to the end of the valve guide 113 on the lubricating oil supply side O, and the amount of lubricating oil supplied to the annular gap between the valve guide 113 and the valve stem 115 is appropriately adjusted. ing.

FIG. 4 shows a conventional valve stem seal 100.
An example is shown. The valve stem seal 100 is a so-called metal fitting type valve stem seal,
Roughly, a metal ring 112 and a sealing member 11 made of a rubber-like elastic body
0.

The metal ring 112 includes a cylindrical portion 112b fitted on the outer periphery of the valve guide 113, and a flange portion 112a bent inward from the cylindrical portion 112b. The inner diameter of the cylindrical portion 112b of the metal ring 112 is
3 is designed to be substantially the same as the outer diameter of the valve stem 113. When the metal ring 112 is assembled to the valve guide 113, a sufficient tightening force is generated and the valve stem seal 100 can be securely fixed.

A seal member 110 is provided on a flange portion 112a of a metal ring 112, and a lip portion 110a sliding on an outer peripheral surface of a valve stem 115 is provided on an inner peripheral side thereof.
Is formed. A spring 111 for maintaining the pressing force of the lip portion 110a (the tightening force of the valve stem 115) for a long period of time is provided on the outer periphery of the seal member 110.
Is installed.

FIGS. 7A and 7B show a valve stem seal 200 of a so-called rubber fitting type and a valve guide 2 into which the valve stem seal 200 is inserted.
13 is shown.

The valve stem seal 200, like the valve stem seal 100, is generally composed of a metal ring 212 and a seal member 210. The metal ring 212 is connected to the lubricating oil supply side O of the valve guide 213. The part is inserted and fixed.

However, the inner diameter of the cylindrical portion 212b of the metal ring 212 is provided to be larger than the outer diameter of the valve guide 213, and the inner peripheral surface of the cylindrical portion 212b has a sealing member 210.
Are extended to form a rubber fitting portion 210b.

That is, the cylindrical portion 212b of the metal ring 212
A rubber fitting portion 210b having substantially the same diameter as or smaller than the outer diameter of the valve guide 213 is formed on the inner peripheral side of the valve guide 213.
13, a tightening force is generated in the rubber fitting portion 210 b to fix the valve stem seal 200.

[0015]

However, the following problems have arisen when manufacturing the above-mentioned prior art valve stem seal.

The above-described valve stem seal according to the prior art utilizes the rigidity of the metal ring 112 or the elasticity of the rubber fitting portion 210b to generate a tightening force on the inner peripheral surface side of the cylindrical portion of the metal ring, so that the valve guide is formed on the valve guide. It is fitted.

Therefore, in the metal fitting type configuration shown in FIG. 4, deformation of the metal ring 112 when the valve stem seal 100 is assembled to the valve guide 113,
In order to prevent the valve stem seal 100 from coming off due to insufficient fitting force, it is necessary to strictly control the inner diameter of the cylindrical portion 112b of the metal ring 112.

At least as shown in FIG.
It is necessary to manage two dimensions: an inner diameter D1 near the opening end of the opening 12b and an inner diameter D2 closer to the flange 112a, and D1 <D2 to prevent deformation during assembly. Must be designed.

In such a case, the inner diameter of the cylinder must be measured. However, since it is often difficult to visually check the position, it is necessary to use special measuring equipment or a high measuring technique. The high load of dimensional control during manufacture of the stem seal has been a problem.

On the other hand, in the configuration of the rubber fitting type valve stem seal 200 shown in FIG. 7, although stricter dimensional control is not required than the metal fitting type, the shaft tightening force of the rubber fitting portion 210b is supplemented. In order to increase the fitting force, a process such as providing a notch 213a in the valve guide 213 has been required.

Further, when assembling the above-mentioned conventional valve stem seal to a valve guide, the following problems occur.

FIG. 5 shows a state where the valve stem seal 100 of the metal fitting type is normally assembled to the valve guide 113. In order to obtain a sufficient fitting force between the valve stem seal 100 and the valve guide 113, the valve stem seal 100 must be firmly inserted to a predetermined amount.
6, the valve stem seal 100 may be deformed and damaged as shown in FIG.

As described above, when assembling the valve stem seal, the driving height h2 and the driving load must be strictly controlled in order to prevent deformation and insufficient fitting at the time of assembling. I needed skills.

Further, in the conventional valve stem seal, the valve stem seal and the valve guide cannot be reduced in size because the cylindrical metal ring is inserted into the valve guide. Therefore, as shown in FIG. 5, the height h1 from the reference surface 114a to the upper surface of the seal is unnecessarily high, which has been a problem in downsizing the cylinder head.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and has as its object a simple configuration, easy dimensional control at the time of manufacture, and easy assembling. To provide a simple valve stem seal.

[0026]

In order to achieve the above object, according to the present invention, a seal is provided between a sleeve-shaped valve guide and a valve stem inserted through the valve guide. Attached to one end of the valve guide,
In a valve stem seal provided with a seal member that slides on an outer peripheral surface of the valve stem, a washer fitted on a fitting portion formed on an end surface of the valve guide is provided on the valve guide side of the seal member. It is characterized by having.

Here, the washer refers to a flat ring-shaped member made of a metal material, and has a simple rectangular cross section. By using a washer as a means for fitting the valve stem seal to the valve guide, the configuration becomes extremely simple as compared with a conventional configuration using a cylindrical metal ring, and dimensional control during manufacturing is facilitated, and the valve is easily manufactured. The size of the stem seal itself can be reduced.

Further, since the washer is provided on the valve guide side of the seal member, the seal member and the valve guide do not directly interfere with each other, so that deformation and damage of the seal member due to erroneous assembly can be prevented. Also, since a dedicated fitting portion for fitting the washer is formed on the end face of the valve guide, the valve stem seal can be correctly positioned with respect to the valve guide simply by fitting the washer into the fitting portion. Can be assembled.

Preferably, the washer has a contact surface that abuts against the valve guide in the axial direction.

According to this structure, the valve stem seal is driven into the correct assembling position by driving the valve stem seal until the contact surface of the washer comes into contact with the valve guide, so that the driving height and the driving load are strictly controlled. It is possible to prevent poor assembly such as excessive assembly or insufficient fitting without performing the above steps.

The washer may be fitted to the fitting portion of the valve guide on the inner peripheral surface or the outer peripheral surface.

[0032]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) A valve stem seal according to a first embodiment of the present invention will be described with reference to FIG.

FIG. 1A is a longitudinal half sectional view of a valve stem seal 1 according to the present embodiment, and FIG. 1B is a schematic sectional view showing a mounted state of the valve stem seal 1. .

The valve stem seal 1 is applied to an intake or exhaust valve mechanism of an engine mounted on an automobile or the like. As shown in FIG. Valve guide 1
A seal is provided between one end of the valve stem 3 and a valve stem 15 slidably inserted into the valve guide 13.

The valve stem seal 1 is provided on the lubricating oil supply side O
The amount of the lubricating oil supplied from the valve is appropriately adjusted, and the lubrication between the valve stem 15 and the valve guide 13 is ensured, while preventing oil leakage to the port side P.

Since the structure and operation of the valve mechanism have been described in detail in the above-mentioned prior art, the description is omitted here.

[0038] Valve stem seal 1 according to the present embodiment.
The seal member 1 is attached to the washer 12 which is a flat ring-shaped member.
The seal member 10 is provided with a spring 11 on the outer periphery thereof.

The seal member 10 is made of a rubber-like elastic material such as acrylic rubber, silicone rubber, or fluorine rubber, and is preferably made of fluorine rubber having excellent oil resistance and abrasion resistance at high temperatures.

On the inner peripheral side of the seal member 10, a lip portion 10 having a wedge-shaped cross section that slides on the outer peripheral surface of the valve stem 15 is provided.
a is formed. The inner diameter of the tip of the lip portion 10a is designed to be smaller than the outer diameter of the valve stem 15, and an appropriate interference is formed between the lip portion 10a and the valve stem 15.

Therefore, when the valve stem 15 is inserted through the valve stem seal 1, the lip portion 10a (seal member 10) is elastically deformed in the radially increasing direction, and the elastic force of the lip portion 10a causes the pressing force (tightening) against the valve stem 15. Force).

The spring 11 is a ring made of a spring made of a steel wire, a piano wire, or the like, and is mounted on the outer periphery of the seal member 10 so as to be located substantially behind the lip portion 10a.

The spring 11 allows the lip 1
0a is increased and the pressing force is maintained for a long period of time, so that the life of the valve stem seal 1 can be prolonged in addition to the improvement of the followability to the eccentricity and the variation of the outer diameter of the valve stem 15. it can.

As shown in FIG. 1A, a washer 1 is provided at the end of the seal member 10 on the valve guide 13 side.
2 are provided.

In the present embodiment, the washer 12 is a ring-shaped member having a rectangular cross section, and the seal member 10 is attached to the lubricating oil supply side O from the end surface to the inner peripheral surface. The guide-side end surface 12b has a configuration in which the entire washer surface is exposed.

Next, with reference to FIG. 1B, the structure of the valve guide 13 for assembling the valve stem seal 1 having the above-described structure and a method of assembling the same will be described.

As shown in the figure, a fitting portion corresponding to the washer 12 of the valve stem seal 1 is formed on the end face of the valve guide 13 on the lubricating oil supply side O (the valve stem seal side). In the present embodiment, the fitting portion wall surface 13a
And the fitting portion bottom surface 13b form a fitting portion.

The inner diameter of the fitting portion wall surface 13a is substantially the same as the outer diameter of the washer 12, and the depth of the fitting portion bottom surface 13b is
2 are designed to be substantially the same as the axial width t.

Therefore, when the valve stem seal 1 is assembled from above the valve guide 13, the end face 12 b of the washer 12 abuts against the fitting part bottom face 13 b of the valve guide 13, and the valve stem seal 1 is positioned. At this time, the seal member 10 does not contact the valve guide 13.

Then, the outer peripheral surface 12a of the washer 12 comes into close contact with the fitting portion wall surface 13a, and a fitting force acts between the both, so that the valve stem seal 1 is fixed.

That is, the end surface 12b of the washer forms a contact surface that abuts against the valve guide 13 in the axial direction, and regulates the axial movement of the valve stem seal 1. On the other hand, the outer peripheral surface 12a of the washer abuts against the valve guide 13 in the radial direction, thereby restricting the radial movement of the valve stem seal 1.

The strength of the fitting force acting on the washer 12 and the valve guide 13 depends on the contact area between the outer peripheral surface 12 a of the washer 12 and the fitting portion wall surface 13 a of the valve guide 13. The width t of the washer 12 and the bottom surface 1 of the fitting portion are determined based on the required fitting force.
What is necessary is just to design the depth of 3b suitably.

According to the configuration of the present embodiment, only the outer diameter of the washer 12 needs to be strictly controlled. Such a measurement location is a location that can be easily visually confirmed, and one measurement is necessary and sufficient depending on the width t of the washer 12, so that dimensional control during manufacturing is extremely easy as compared with the related art.

Further, since the washer 12 is provided on the valve guide side of the seal member 10, the seal member 10 and the valve guide 13 do not directly interfere with each other, and the deformation and damage of the seal member 10 due to an assembly error can be prevented. Can be.

Further, since a dedicated fitting portion for fitting the washer 12 is formed on the end face of the valve guide 13, the valve stem seal 1 can be mounted only by fitting the washer 12 into the fitting portion. The valve guide 13 can be assembled at a correct position.

At this time, the valve stem seal 1 can be positioned at a correct assembling position only by driving the valve stem seal 1 until the end surface 12b of the washer 12 abuts against the fitting portion bottom surface 13b of the valve guide 13, so that the driving height and the driving load are strictly controlled. It is possible to prevent poor assembly such as excessive assembly or insufficient fitting without performing the above steps.

Further, compared with the conventional valve stem seal,
The size can be reduced, and the number of ring materials can be reduced. Then, since the valve stem seal itself becomes smaller, the height of the valve guide to which the valve stem seal is assembled can be reduced, and as a result, the size of the cylinder head itself can be reduced.

In the present embodiment, the height h from the reference surface 14a to the upper surface of the valve stem seal 1 is reduced to half or less as compared with the prior art, and the valve guide 13 from the reference surface 14a is reduced.
The guide height up to the upper surface could be reduced to about 1/3 of the conventional height.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention. In the first embodiment, the valve guide is fitted on the outer peripheral surface of the washer. In the present embodiment, the valve guide is fitted on the inner peripheral surface of the washer.

Since other structures and operations are the same as those of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.

FIG. 2A is a longitudinal half sectional view of the valve stem seal 2 according to the present embodiment, and FIG. 2B is a schematic sectional view showing a mounted state of the valve stem seal 2. .

The valve stem seal 2 according to the present embodiment
The seal member 1 is attached to the washer 22 which is a flat ring-shaped member.
The seal member 10 is provided with a spring 11 on the outer periphery thereof.

The washer 22 is a ring-shaped member having a rectangular cross section, and is provided at the end of the seal member 10 on the valve guide 23 side. Then, as shown in FIG. 2A, the seal member 10 is attached to the end face on the lubricating oil supply side O, and the inner peripheral face 22a, the outer peripheral face, and the end face 22b on the valve guide side are all exposed with the washer face. It has become.

On the other hand, the valve guide 23 to which the valve stem seal 2 having the above configuration is assembled has a configuration shown in FIG.

That is, a fitting portion corresponding to the washer 22 of the valve stem seal 2 is formed on the end face on the lubricating oil supply side O (the valve stem seal side) of the valve guide 23. In the present embodiment, a fitting portion is constituted by the fitting portion wall surface 23a and the fitting portion bottom surface 23b.

The outer diameter of the fitting portion wall surface 23a is substantially the same as the inner diameter of the washer 22, and the depth of the fitting portion bottom surface 23b is
2 are designed to be substantially the same as the axial width t.

Accordingly, when the valve stem seal 2 is assembled from above the valve guide 23, the end face 22b of the washer 22 abuts against the fitting portion bottom face 23b of the valve guide 23, and the valve stem seal 2 is positioned. At this time, the seal member 10 does not contact the valve guide 23.

Then, the inner peripheral surface 22a of the washer 22 comes into close contact with the fitting portion wall surface 23a, and a fitting force acts between the both, so that the valve stem seal 2 is fixed.

That is, the end face 22 b of the washer forms an abutting surface that abuts against the valve guide 23 in the axial direction, and regulates the axial movement of the valve stem seal 2. On the other hand, the inner peripheral surface 22a of the washer abuts against the valve guide 23 in the radial direction, thereby restricting the radial movement of the valve stem seal 2.

The strength of the fitting force acting on the washer 22 and the valve guide 23 depends on the contact area between the inner peripheral surface 22a of the washer 22 and the fitting portion wall surface 23a of the valve guide 23. The width t of the washer 22 and the bottom surface 2 of the fitting part are determined based on the fitting force sometimes required.
What is necessary is just to design the depth of 3b suitably.

In the configuration of the present embodiment, the first
The same operation and effect as those of the embodiment can be obtained, and the dimensional control and the assembling at the time of manufacturing can be facilitated.

In the case of this embodiment, strict dimensional control of the inner diameter of the washer 22 is required. However, since such measurement points are easy to visually confirm, the dimensional control is performed in the same manner as in the first embodiment. Needless to say, this is easy.

In the above embodiment, a washer having a rectangular cross section is used. However, the shape of the washer is not limited to this, and at least a surface that is tightly fitted to the valve guide and an axial direction with respect to the valve guide are used. What is necessary is that it has a substantially rectangular cross section provided with a surface that abuts on the surface. For example, chamfering may be performed to further facilitate the assembling, and grooves or protrusions may be provided on the bonding surface to strengthen the bonding with the seal member.

[0074]

As described above, the present invention has a structure in which the seal is provided on the valve guide side of the seal member with the washer fitted to the fitting portion formed on the end face of the valve guide. Compared to a configuration having a metal ring, the configuration is extremely simple, dimensional control during manufacture is easy, and the valve stem seal itself can be reduced in size.

Further, at the time of assembling the valve stem seal, the seal member and the valve guide do not directly interfere with each other, so that deformation and damage of the seal member due to an erroneous assembly can be prevented. Since the exclusive fitting portion is formed, the valve stem seal can be assembled at a correct position with respect to the valve guide only by fitting the washer into the fitting portion.

Further, by providing the washer with an abutting surface that abuts against the valve guide in the axial direction, the valve stem seal can be correctly assembled only by driving the valve stem seal until the abutting surface of the washer abuts the valve guide. It is positioned at the position, and it is possible to prevent poor assembly such as excessive assembly or insufficient fitting without strictly controlling the driving height and the driving load.

[Brief description of the drawings]

FIG. 1A is a longitudinal half sectional view of a valve stem seal according to a first embodiment of the present invention, and FIG. 1B is a schematic sectional view showing a mounted state thereof.

FIG. 2 (a) is a longitudinal half sectional view of a valve stem seal according to a second embodiment of the present invention, and FIG. 2 (b) is a schematic sectional view showing a mounted state thereof.

FIG. 3 is a sectional view of a main part showing a valve mechanism of a cylinder head of the engine.

FIG. 4 is a longitudinal half sectional view of a conventional metal fitting type valve stem seal.

FIG. 5 is a schematic sectional view showing a normal mounting state of the valve stem seal of FIG. 4;

FIG. 6 is a schematic sectional view showing an excessively assembled state of the valve stem seal of FIG. 4;

7A is a longitudinal half sectional view of a conventional rubber fitting type valve stem seal, and FIG. 7B is a longitudinal half sectional view of a valve guide to which the valve stem seal of FIG. .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve stem seal 10 Seal member 10a Lip part 11 Spring 12 Washer 12a Outer peripheral surface 12b End surface 13 Valve guide 13a Fitting wall surface 13b Fitting bottom surface 15 Valve stem 2 Valve stem seal 22 Washer 22a Inner peripheral surface 22b End surface 23 Valve guide 23a fitting portion wall surface 23b fitting portion bottom surface

Claims (3)

[Claims] 1. A seal between a sleeve-shaped valve guide and a valve stem inserted through the valve guide, wherein the seal is mounted on one end of the valve guide and slides on an outer peripheral surface of the valve stem. A valve stem seal provided with a seal member, comprising: a washer fitted on a fitting portion formed on an end face of the valve guide on the valve guide side of the seal member. 2. The valve stem seal according to claim 1, wherein the washer has a contact surface that abuts the valve guide in an axial direction. 3. The valve stem seal according to claim 1, wherein the washer is fitted to a fitting portion of the valve guide on an inner peripheral surface or an outer peripheral surface.