JP2003041912A - Rocker arm with hydraulic tappet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rocker arm with hydraulic tappet, capable of improving the rigidity of a rocker arm itself and improving the rigidity of a fixing part for fixing a hydraulic tappet. SOLUTION: In this integrated type rocker arm 1 equipped with a first and a second valve abutting parts 12, 13 abutted against two valves, the respective first and second valve abutting parts 12, 13 are provided with the hydraulic tappets 5, 5. The first and second fixing parts 12a, 13a for fixing the respective hydraulic tappets 5, 5 on the integrated type rocker arm 1 are jointed by a hydraulic tappet jointing wall 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rocker arm for driving an engine valve in an opening direction, and more particularly to a rocker arm with a hydraulic tappet.

[0002]

2. Description of the Related Art In recent years, as an automobile engine structure, OH such as SOHC (single overhead camshaft) and DOHC (double overhead camshaft) is used.
The C type is the mainstream. In such a type, when the rotational force of the cam shaft is transmitted to the rocker arm via the cam, the rocker arm swings around the rocker shaft. The tip of the rocker arm pushes the valve, which comes into contact with the tip, against the urging force of the valve return spring in the closing direction, thereby driving the valve in the opening direction. In the technique disclosed in Japanese Utility Model Publication No. 7-5204 as the structure of the rocker arm, a hydraulic tappet is provided at the tip of the rocker arm in order to constantly adjust the clearance between the tip and the valve.

[0003]

By the way, in the rocker arm with the hydraulic tappet as described above, the base end portions of the two rocker arms provided on the exhaust valve side are integrated to reduce the number of parts and the rigidity of the rocker arm. We are trying to improve However, in recent years,
It is desired to further improve the rigidity of this integrated rocker arm. Further, in order to fit and fix the hydraulic tappet, a fixed portion made of a bottomed cylinder is provided at the tip of the rocker arm, and it is also desired to improve the rigidity of this fixed portion.

Therefore, an object of the present invention is to provide a rocker arm with a hydraulic tappet capable of increasing the rigidity of the rocker arm itself and the rigidity of a fixing portion for fitting and fixing the hydraulic tappet.

[0005]

The invention according to claim 1 of the present invention, which has solved the above-mentioned problems, is a rocker arm having a valve abutting portion that abuts a plurality of valves. Each of them is provided with a hydraulic tappet, and each fixing portion for fitting and fixing each of the hydraulic tappets to the rocker arm is connected by a hydraulic tappet connecting wall.

According to the first aspect of the present invention, since the fixed portions, which receive the largest reaction force from the valve, are connected by the hydraulic tappet connecting wall, the rigidity of the rocker arm itself is increased, and The rigidity of the fixed part of the hydraulic tappet can also be increased.

According to a second aspect of the present invention, in the structure of the first aspect of the invention, the rocker arm is swingably supported by a rocker shaft and is supported by a rocker shaft support portion pivotally supported by the rocker shaft. A plurality of connecting walls that are connected to the plurality of valve abutting portions, and a roller that rolls with the cam surface between the valve abutting portions and the rocker shaft support portion and between the respective connecting walls; A first oil passage that communicates with the hydraulic tappet from an oil passage formed in the rocker shaft is provided on one end of the connecting wall, and a roller of the roller is provided on the other end of the connecting wall. An insertion hole for inserting the shaft is formed, and the hydraulic tappet connecting wall is provided with a second oil passage communicating between the hydraulic tappets.

According to the invention of claim 2, claim 1
In addition to the effect of the invention described in (1), the oil passage is provided in a rigid place by providing the oil passage in the connecting wall and the hydraulic tappet connecting wall. That is, the oil passage can be provided without reducing the rigidity of the rocker arm itself.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] The details of a rocker arm with a hydraulic tappet according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to an integrated rocker arm that simultaneously drives two exhaust valves in a DOHC type multi-cylinder engine.

As shown in FIG. 1, an integrated rocker arm 1
Is a rocker shaft supporting portion 11 swingably supported by the rocker shaft 2 as a base end portion, and a tip end portion of the rocker shaft supporting portion 11 is in contact with stem ends of two exhaust valves (not shown).
Second valve contact portions 12, 13 are provided. The first valve contact portion 12 and the second valve contact portion 13 are connected by a hydraulic tappet connecting wall 14. First valve contact portion 12 and rocker shaft support portion 1
1 is connected by a first connecting wall 15 extending in a direction perpendicular to the axial direction of the rocker shaft 2, and between the second valve contact portion 13 and the rocker shaft supporting portion 11 is also a first connecting wall. They are connected by a second connecting wall 16 having substantially the same shape as 15. Then, the rocker shaft support portion 11, the hydraulic tappet connecting wall 14, the first and second connecting walls 15, 1
At the inner side of 6, the central support portion 1 for supporting these from the inside is provided.
7 is provided. Here, the rocker shaft support 1
The first and second valve contact portions 12 and 13, the hydraulic tappet connecting wall 14, the first and second connecting walls 15 and 16 and the central support portion 17 are integrally formed by casting.

As shown in FIG. 2, the rocker shaft supporting portion 11 has a through hole 1 through which the rocker shaft 2 is inserted.
1a is formed, and an escape portion 11b is formed at the center in the axial direction so as not to interfere with an ignition plug (not shown). The first and second valve contact portions 12, 13 are provided with bottomed first and second bottomed holes 12a, 13a for mounting the hydraulic tappet 5 (see FIG. 4) from the lower surface side thereof, respectively. Has been formed. The first and second bottomed holes 12a,
As shown in FIG. 4, 13a has a hydraulic tappet 5 having a diameter.
Are formed stepwise according to the outer diameter of the component.
The cylindrical member 51 of the hydraulic tappet 5 is fitted and fixed to the second largest diameter portion of the first and second bottomed holes 12a and 13a, and the plunger 52 is fitted onto the cylindrical member 51 while It is slidably engaged by being inserted in the part with the second largest diameter. Then, the fitted cylindrical member 51
The portion that encloses the first and second fixing portions 12 to which a reaction force from the valve is particularly applied when the integrated rocker arm 1 is driven.
b and 13b. The first and second fixing parts 12
b and 13b are connected by the hydraulic tappet connecting wall 14.

The central support portion 17 has a hollow roller housing 1 in which the roller 3 is interposed and which penetrates vertically.
7a is formed, and a bottomed insertion hole 15a formed from the first connecting wall 15 side toward the central support portion 17 is formed so as to communicate with the roller housing 17a. The inner diameter of the insertion hole 15a in the vicinity of a portion communicating with the roller housing 17a is made smaller in accordance with the size for press-fitting the hollow roller shaft 4, and the other portions are formed for processing and weight saving. The lightening portions N and N have an increased inner diameter. Further, the roller shaft 4 is shortened according to the length of the portion of the insertion hole 15a where the inner diameter is reduced (hereinafter referred to as press-fit length), and the roller 3 is located at a position approximately in the middle of the press-fit length. The insertion hole 15a is formed to have a smaller inner diameter so as to be located.
Further, the center of the roller shaft 4 is located between the surface including the upper surface 14c (see FIG. 3) of the hydraulic tappet connecting wall 14 and the surface including the lower surface thereof. Then, when the roller 3 is interposed in the roller housing 17a of the central supporting portion 17 and the roller shaft 4 is press-fitted into a portion where the inner diameter of the insertion hole 15a is small, the roller 3 is rotatably supported by the roller shaft 4. It When a cam of a cam shaft (not shown) comes into contact with the roller 3 from above and rolls, the tip of the integrated rocker arm 1 swings up and down around the rocker shaft 2 to open and close a valve (not shown). In the present embodiment, the insertion hole 15 for press-fitting the roller shaft 4 is inserted.
The roller 3 is formed such that the portion of the inner diameter a of which the diameter is reduced is located approximately in the middle of the press-fitting length, but the present invention is not limited to this. For example, the roller shaft 4 is inserted so that the press-fitting length of the roller shaft 4 on the side of the first connecting wall 15 is longer than the press-fitting length of the roller shaft 4 on the side of the closed second connecting wall 16 with the roller 3 as the center. By forming the portion having the small inner diameter of the hole 15a, the support rigidity of the roller shaft 4 and the rigidity of the integrated rocker arm 1 can be increased.

The second connecting wall 16 is provided with a first oil passage 16a which communicates with the through hole 11a of the rocker shaft supporting portion 11 and the second bottomed hole 13a of the second valve contact portion 13. The first bottomed hole 12 is formed in the hydraulic tappet connecting wall 14.
A second oil passage 14a is provided which communicates with a and the second bottomed hole 13a. The second oil passage 14a is formed in a straight line connecting the vicinity of the center of the first bottomed hole 12a and the center of the second bottomed hole 13a, and the first and second bottomed holes 1
The openings 2a and 13a are opened at predetermined positions above the inner peripheral wall having the largest diameter. Therefore, the hydraulic tappet connecting wall 14 is outwardly positioned in a direction away from the rocker shaft 2 with respect to a straight line whose outer surface 14b connects the vicinity of the center of the first bottomed hole 12a and the center of the second bottomed hole 13a. This outer surface 14b must be provided, and in this embodiment, the outer surface 14b is located so as to connect the tips of the first and second valve contact portions 12 and 13. Further, as shown in FIG. 3, the upper surface 14c of the hydraulic tappet connecting wall 14 slides the plunger 52 more than the predetermined positions of the first and second bottomed holes 12a and 13a where the second oil passage 14a opens. Second oil passage 14a in the direction
Is provided above the opening.

As shown in FIG. 4, an oil supply passage (oil passage) 2a penetrating in the axial direction is formed in the rocker shaft 2, and an oil pump (not shown) supplies oil to the oil supply passage 2a at a predetermined pressure. Is being supplied. This oil is supplied to the through hole 11a of the rocker shaft support portion 11 through the hole 2b penetrating from the inside of the oil supply passage 2a to the outside, thereby lubricating the sliding between the through hole 11a and the rocker shaft 2. .
The oil filling the space between the through hole 11a and the rocker shaft 2 is supplied into the second bottomed hole 13a through the first oil passage 16a. The oil filling the second bottomed hole 13a is supplied into the first bottomed hole 12a through the second oil passage 14a.
Then, excess oil is discharged to the outside through the holes 12c and 13c (see FIG. 1) provided on the bottom surfaces of the first and second bottomed holes 12a and 13a, and this oil is discharged to the integrated rocker arm 1
Flows over the upper surface of the roller and is used as lubricating oil for the roller 3. Further, below the holes 12c and 13c, as shown in FIG. 5, holes 12d and 13d communicating from a predetermined position at the bottom of the first and second bottomed holes 12a and 13a toward the roller 3.
The holes 12d and 13d are formed, and the oil is positively collected in the depression on the upper surface of the integrated rocker arm 1 and the roller 3
Can be lubricated. The oil thus supplied fills the holes, oil passages, etc. when the engine is driven, so the first and second bottomed holes 1
The hydraulic tappets 5 and 5 in 2a and 13a move with the same hydraulic pressure.

According to the above configuration, the following effects can be obtained in the first embodiment. Since the first and second fixing portions 12b and 13b for fitting and fixing the cylindrical members 51 and 51 of the hydraulic tappets 5 and 5 are connected by the hydraulic tappet connecting wall 14, the rigidity of the integrated rocker arm 1 itself. And the rigidity of the first and second fixing portions 12b and 13b can be increased. Further, since the hydraulic tappet connecting wall 14 connects the tips of the first and second valve contact portions 12 and 13, the stress concentration point can be eliminated. Hydraulic tappet connection wall 1
4 is provided with a second oil passage 14a, and the second connecting wall 1
Since the first oil passage 16a is provided inside the rocker arm 6, the rigidity of the integrated rocker arm 1 itself is not reduced, and the first oil passage 16a is provided on the closed second connecting wall 16 side. An oil passage from the center of the shaft 2 to the hydraulic tappet 5 can be linearly provided. Also, by providing the oil passage in a straight line shape, the corner can be easily machined without complicating the oil passage. Since the roller shaft 4 is hollow and the length thereof is short, the weight of the integrated rocker arm 1 can be reduced. Further, since the diameter of the portion of the insertion hole 15a into which the roller shaft 4 is not press-fitted is large, this portion serves as the lightening portions N, N for reducing the weight, and the integral rocker arm 1 can be reduced in weight. Further, since the center of the roller shaft 4 is located between the upper and lower surfaces of the hydraulic tappet connecting wall 14, the first and second valve contact portions 12, 13 should be provided on the rocker shaft 2 side as much as possible. Therefore, the integrated rocker arm 1 can be made more compact. Since the first connection wall 15 that connects the first valve contact portion 12 and the rocker shaft support portion 11 is provided above and below the lightening portion N on the opening side of the insertion hole 15a, The rigidity of the body type rocker arm 1 can be improved.

[Second Embodiment] A second embodiment of the rocker arm with a hydraulic tappet according to the present invention will be described below. In this embodiment, the structure of the integrated rocker arm 1 in the first embodiment is partially modified to
Since it is applied to a C-type multi-cylinder engine, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The integrated rocker arm 1'shown in FIGS. 6 (a) and 6 (b) is arranged on the exhaust valve side (not shown),
The difference from the first embodiment is that the position of the roller 3 and the position of the rocker shaft support 11 are interchanged. In this structure, when the roller 3 located at the base end of the integrated rocker arm 1'is pushed upward by the profile portion 61 of the cam of the cam shaft 6, the integrated rocker arm 1'is swung about the rocker shaft 2. Hydraulic tappets 5 and 5 provided at the tip end push down an exhaust valve (not shown). When the profile portion 61 of the cam is removed from the roller 3, the tip end of the integrated rocker arm 1'is pushed upward by a valve return spring (not shown) to close the exhaust valve. Then, as in the first embodiment,
The first and second fixing portions 12b and 13b are connected by the hydraulic tappet connecting wall 14, the second connecting wall 16 is provided with a first oil passage 16a, and the hydraulic tappet connecting wall 14 is provided with a second oil passage 16a. Oil passage 14a is provided. The two rocker arms 7, 7 arranged on the intake valve side (not shown)
Is the camshaft 6 centered on the intake side rocker shaft 8.
The rocker arms 7, which are not shown in the figure swing to open and close the valve.

According to the above construction, also in the second embodiment, as in the first embodiment, the first and second fixing portions 12b, 13b and the first fixing portions 12b, 13b to which the reaction force from the valve is particularly applied. It is possible to increase the rigidity of the body-shaped rocker arm 1 ′, and at the high rigidity portion, the first and second oil passages 16 a,
14a can be provided.

As described above, the present invention is not limited to the above embodiment, but can be implemented in various forms. In the present embodiment, the exhaust side integrated rocker arm is adopted as the rocker arm with the hydraulic tappet, but the present invention is not limited to this. For example, when the intake side integrated rocker arm is provided, the intake side rocker arm is The present invention may be applied.

In this embodiment, the integral rocker arm is provided with two valve abutting portions, but the present invention is not limited to this, and the number of valve abutting portions may be any number. For example, in an integrated rocker arm that moves three valves at the same time, three valve abutting portions are provided. At this time,
A connecting wall extending in a direction perpendicular to the axial direction of the rocker shaft is provided between each valve contact portion and the rocker shaft support portion, and a hydraulic tappet connection wall is provided between each valve contact portion. To be By providing an oil passage on at least one connecting wall among the three connecting walls extending from the three valve abutting portions to the rocker shaft supporting portion, and by providing an oil passage on each hydraulic tappet connecting wall, The same effect as that of the embodiment can be obtained.

In the present embodiment, the integrated rocker arm 1 is formed integrally by casting, but the present invention is not limited to this. For example, the hydraulic tappet connecting wall 14 may be fixed as a separate member with a bolt or the like, or the integral rocker arm may be manufactured by forging, powder metallurgy, precision casting, or the like. Further, it goes without saying that the shape, material, configuration and the like of the integrated rocker arm 1 can be appropriately changed. Further, the shape of the hydraulic tappet connecting wall 14 is not limited to this embodiment, and may be any shape. For example, the hydraulic tappet connecting wall 14 has the first and second fixing portions 12b,
13b are connected to each other, and the lower end portion of the first and second bottomed holes 1
By connecting the vicinity of the opening side of 2a, 13a, the rigidity between the first and second valve contact portions 12, 13 can be increased, so the portion between the upper and lower end portions is appropriately lightened. As a result, it is possible to increase the rigidity while reducing the weight.

[0022]

According to the invention as set forth in claim 1, since each fixing portion for fitting and fixing a plurality of hydraulic tappets to the rocker arm is connected by the hydraulic tappet connecting wall, the rigidity of the rocker arm itself is increased, In addition, the rigidity of the fixed portion of the hydraulic tappet can be increased.

According to the invention of claim 2, claim 1
In addition to the effects of the invention described in (1), it is possible to provide an oil passage in the rigid hydraulic tappet connection wall or the connection wall. That is, the oil passage can be provided without reducing the rigidity of the rocker arm itself.

[Brief description of drawings]

FIG. 1 is a perspective view showing an integrated rocker arm according to a first embodiment.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a cross-sectional view taken along the line CC of FIG.

5 is a cross-sectional view taken along the line DD of FIG.

FIG. 6 is a partially cutaway plan view (a) showing the arrangement of the intake-side rocker arm and the exhaust-side integrated rocker arm according to the second embodiment, and the arrangement of the intake-side rocker arm and the exhaust-side integrated rocker arm. It is a partially broken side view (b) shown.

[Explanation of symbols]

1,1 'Integrated rocker arm 11 Rocker shaft support 12 First valve contact part 12b First fixing part 13 Second valve contact part 13b Second fixed part 14 Hydraulic tappet connection wall 14a Second oil passage 14b outer surface 14c upper surface 15 First connection wall 15a insertion hole 16 Second connection wall 16a First oil passage 2 rocker shaft 2a Oil supply path (oil path) 2b hole 3 roller 4 roller shaft 5 hydraulic tappet

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Junichi Iwamoto             143 Hagadai, Haga-cho, Haga-gun, Tochigi Prefecture             In PSG F term (reference) 3G016 AA07 AA08 AA19 BA03 BA06                       BA18 BA27 BA28 BB09 BB11                       BB17 BB22 BB29 BB38 CA04                       CA12 CA25 CA28 CA29 CA32                       CA35 CA36 CA52 DA18 DA22                       GA00 GA01

Claims (2)

[Claims] 1. A rocker arm having a valve abutting portion that abuts a plurality of valves, wherein each of the valve abutting portions is provided with a hydraulic tappet.
A rocker arm with a hydraulic tappet, wherein each fixing portion for fitting and fixing each of the hydraulic tappets to the rocker arm is connected by a hydraulic tappet connecting wall. 2. The rocker arm includes rocker shafts that are swingably supported by rocker shafts, and rocker shaft support portions pivotally supported by the rocker shafts, which are connected to a plurality of valve contact portions. A roller that rolls with a cam surface is provided between the valve contact portion and the rocker shaft support portion and between each of the connecting walls, and a connecting wall at one end of the connecting walls is provided in the rocker shaft. A first oil passage communicating from the formed oil passage to the hydraulic tappet is provided, an insertion hole for inserting the roller shaft of the roller is formed in the connecting wall at the other end, and the hydraulic tappet inter-connecting wall is provided. The rocker arm with a hydraulic tappet according to claim 1, further comprising a second oil passage that connects between the hydraulic tappets.