JP2015086864A - Roller type rocker arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller type rocker arm capable of preventing occurrence of seizure, and capable of improving friction performance.SOLUTION: A rocker arm 100 includes a roller shaft 120 fixed on a body 110, an inner ring roller 130 rotatably attached to the roller shaft 120, and an outer ring roller 140 rotatably attached to an outer periphery of the inner ring roller 130 and abutted to a cam. The roller shaft 120 has a lubricating oil supply passage 122 and oil holes 124A-124C communicated with a shaft outer periphery from the lubricating oil supply passage 122 in an inside thereof. The inner ring roller 130 has a circumferential groove 132 communicated with the oil hole 124B, and an oil hole 134 communicated with the groove 132. The outer ring roller 140 has a circumferential groove 142 communicated with the oil hole 134 of the inner ring roller 130. Thus, lubricating oil is forcibly supplied to clearances S1 and S2 between the roller shaft and the inner ring roller, and the inner ring roller and the outer ring roller, and an oil film is formed by static pressure effect.

Description

  The present invention relates to a rocker arm type valve operating mechanism for an internal combustion engine, and more particularly, to a roller type rocker arm that comes into contact with a cam of a cam shaft and a roller.

  A rocker arm of an internal combustion engine is installed between a cam of a camshaft and a valve stem of an intake / exhaust valve, and has a function of transmitting the rotational operation of the camshaft to the intake / exhaust valve and converting it to an opening / closing operation of the valve. Yes. In recent years, many roller-type rocker arms have been adopted for the purpose of improving fuel efficiency in valve operating mechanisms of 4-stroke internal combustion engines. The roller-type rocker arm has an outer ring roller that slides with a cam on a body (main body) and a roller shaft that supports the outer ring roller. For example, a plurality of needle rollers are interposed between the roller shaft and the roller. There are types that are configured (Patent Document 1), types that are configured via an inner ring roller between the roller shaft and the outer ring roller (Patent Document 2), and the type that uses a roller is a total rolling type, an inner ring roller The type using is classified as a total slip type.

  FIG. 1A shows a schematic perspective view of a sliding type rocker arm, and FIG. 1B shows a schematic perspective view of a rolling type rocker arm. However, the body of the rocker arm is omitted here. The slide-type rocker arm 10 includes a roller shaft 12, an inner ring roller 14 that is rotatably mounted on the outer periphery of the roller shaft 12, and an outer ring roller 16 that is rotatably mounted on the outer periphery of the inner ring roller 14. . The rolling-type rocker arm 20 includes a roller shaft 22, a plurality of needle rollers 24 that are rotatably attached to the outer periphery of the roller shaft 22, and a roller 26 that is rotatably attached to the outer periphery of the needle roller 24. .

  FIG. 2 is a view showing an example of a rolling-type rocker arm installed between the cam of the camshaft and the valve stem of the intake / exhaust valve. The rocker arm includes a body 30 that rotatably holds a roller 26 as shown in FIG. 1B. One end 32 of the body 30 is supported by a pivot portion 34, and the other end 36 is intake / exhaust. A valve spring 39 that abuts against a cap 38 of the valve stem 37 of the valve and biases the end portion 36 of the rocker arm is attached below the cap 38. Thus, the roller 26 is brought into contact with the cam 40, and the rotational movement of the cam 40 is transmitted to the body 30, and the other end 36 moves the intake / exhaust valve up and down according to the rotation of the cam 40. A slide-type rocker arm is also used in the same manner. FIG. 2A shows another example in which the rocker arm is supported by a hydraulic lash adjuster. As shown in the figure, one end 32 of the rocker arm is brought into contact with a plunger 52 having a hemispherical top, and the plunger 52 is supported by the lash adjuster body 50. The lash adjuster body 50 supports the plunger 52 so as to be slidable in the axial direction. Such lash adjuster type rocker arms are disclosed in Patent Documents 1 and 2.

  The total rolling type is used in a state where the rollers roll during engine operation. Therefore, the friction performance is better than the total sliding type, but the roller, the roller shaft and the outer ring roller are in a sliding state close to line contact, so the surface pressure becomes high and it can be applied to a valve mechanism that increases the load. It's getting harder. On the other hand, the total slip type supports the camshaft lift load on the outer ring roller and inner ring roller, and the inner ring roller and the outer periphery of the roller shaft. Application to a valve operating mechanism is under consideration. In such a conventional rocker arm, Patent Documents 3 to 7 disclose techniques for suppressing wear and preventing a decrease in life.

JP 2011-1906 A JP 2012-154226 A JP 2006-312916 A JP 2000-34907 A JP 2005-256656 A JP 2007-23817 A JP 2007-263023 A

  A conventional total sliding type roller-type rocker arm as shown in FIG. 1 (A) is a spray that lubricates a sliding portion between a roller shaft 12 and each of the rollers 12 and 14 in the atmosphere inside the engine. Depends on refueling. For this reason, since there is not enough lubricating oil in the sliding portion, sliding occurs in the boundary lubrication region, and there is a problem that seizure (scuffing) occurs and friction (friction loss) increases. Further, since the amount of lubricating oil supplied is small, it is difficult to discharge the wear powder by the lubricant, and when wear occurs, the wear powder promotes wear. As wear progresses, the lift operation of the intake / exhaust valve cannot follow the camshaft profile, causing abnormal behavior unique to the valve mechanism such as jumping, bouncing, and surging, resulting in failure to obtain the prescribed performance. was there.

  On the other hand, in order to prevent seizure and reduce friction loss even in a poorly lubricated state, the inner ring roller is subjected to surface treatment (Patent Document 2), or inclined surfaces are formed at both ends in the width direction of the outer circumferential surface of the inner ring roller. In other words, fluid lubrication is maintained (Patent Document 3). Furthermore, a hole for forming an opening for introducing the lubricating oil is provided in the support shaft fixed to the main body of the rocker arm, and the lubricating oil is supplied to the gap between the roller and the support shaft (Patent Literature). 4, 5).

  However, the surface treatment of the inner ring roller and the formation of inclined surfaces at both end portions in the width direction of the outer peripheral surface of the inner ring roller depend on the supply of lubricant to the sliding portion depending on the splash oil supply. As a result, sufficient lubricating oil is not supplied. Further, in Patent Documents 4 and 5, a hole for forming an opening for introducing lubricating oil is provided in the support shaft. However, just by providing a hole in the support shaft, the peripheral surface of the support shaft and the inner peripheral surface of the roller are provided. There is a problem that the lubricating oil is not sufficiently supplied to the gap, and the friction at the start-up is particularly large. Also, a means for supplying lubricating oil to the sliding portion between the inner and outer ring rollers is not shown.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a roller rocker arm that prevents the occurrence of seizure and improves the friction performance of a roller type rocker arm of a total slip type for an internal combustion engine.

  The inventor forcibly applies lubricating oil to the sliding part between the inner shaft roller and the inner ring roller of the all-slide type roller rocker arm, and between the inner ring roller and the outer ring roller without depending on splash oil supply. And the formation of an oil film using the static pressure effect, it has been conceived that the friction performance at the start-up can be improved and the occurrence of seizure can be prevented. That is, the roller-type rocker arm of the present invention is a rocker arm of an internal combustion engine that is installed between the cam of the camshaft and the valve stem of the intake / exhaust valve and transmits the rotational operation of the cam to the intake / exhaust valve. In the roller-type rocker arm that the outer ring roller comes into contact and has an inner ring roller between the outer ring roller and the roller shaft, the lubricating oil is forcibly supplied to the clearance between the roller shaft and the inner ring roller, the inner ring roller and the outer ring roller, An oil film is formed by a static pressure effect.

  The roller shaft has a lubricating oil supply passage and one or a plurality of oil holes communicating with the outer periphery of the shaft in the axial direction from the lubricating oil supply passage, and the inner ring roller communicates with the oil hole of the roller shaft on the inner peripheral surface. A circumferential groove and one or a plurality of oil holes communicating from the groove to the outer periphery of the inner ring roller, and the outer ring roller further includes a circumferential groove communicating with the oil hole of the inner ring roller on the inner peripheral surface. The inner ring roller and the outer ring roller may form one or a plurality of grooves extending in the axial direction from a circumferential groove formed on each inner circumferential surface. Further, the outer ring roller may form one or a plurality of oil holes communicating from the groove on the inner peripheral surface to the outer periphery of the outer ring roller. The oil hole diameter (cross-sectional area) of this lubricating oil supply passage is preferably smaller for the inner ring roller than for the roller shaft, and smaller for the outer ring roller than for the inner ring roller. More preferably, the lubricating oil supply passage includes a through hole penetrating to the end surface of the roller shaft, and a leakage preventing member for preventing leakage of the lubricating oil is filled in the through hole. More preferably, a metal ball is press-fitted into the through hole as the leakage preventing member.

  According to the present invention, the lubricating oil is forcibly supplied to the clearance between the roller shaft and the inner ring roller, and the clearance between the inner ring roller and the outer ring roller, and an oil film is formed by a static pressure effect, thereby improving the friction performance at the time of startup. At the same time, it is possible to prevent scuffing. The roller shaft includes a lubricating oil supply passage and one or a plurality of oil holes communicating with the outer periphery of the shaft in the axial direction from the lubricating oil supply passage, and the inner ring roller has an oil hole of the roller shaft on the inner periphery. A circumferential groove communicating with the groove and one or a plurality of oil holes communicating with the outer periphery from the groove, and the outer ring roller further includes a circumferential groove communicating with the oil hole of the inner ring roller on the inner periphery. By using a structure that forcibly supplies oil, it is possible to forcibly supply lubricating oil to each sliding part without depending on the splash oil that exists in the atmosphere, and to improve the friction performance at startup Is possible.

1A is a schematic perspective view showing a conventional roller rocker arm (slip type), and FIG. 1B is a schematic perspective view showing a conventional roller rocker arm (rolling type). It is a schematic diagram which shows an example in which the rocker arm was applied to the internal combustion engine. It is a schematic diagram which shows the other example in which the rocker arm was applied to the internal combustion engine. It is the schematic sectional drawing which showed an example of the structure of the roller type rocker arm which concerns on the 1st Embodiment of this invention. It is the perspective view which notched some roller type rocker arms concerning a 1st embodiment of the present invention. It is the schematic sectional drawing which showed the other example of the structure of the roller type rocker arm which concerns on the 2nd Embodiment of this invention. The other example of the perspective view which notched a part of roller type rocker arm which concerns on the 2nd Embodiment of this invention is shown.

  Next, the form for implementing this invention is demonstrated in detail. It should be noted that in the drawings, each part is highlighted for easy understanding, and is different from an actual scale.

  A rocker arm according to an embodiment of the present invention is a component that constitutes a valve mechanism of a four-stroke internal combustion engine, that is, is installed between a cam of a camshaft and a valve stem of an intake / exhaust valve, and intake / exhaust the cam operation. It has a function to transmit to the valve. FIG. 3 is a schematic cross-sectional view of the rocker arm according to the first embodiment of the present invention, and FIG. 4 is a perspective view in which a part of the roller rocker arm according to the first embodiment of the present invention is cut away. As shown in these drawings, the rocker arm 100 includes at least four parts including a body (main body) 110, a roller shaft 120, and two rollers 130 and 140 of an inner ring and an outer ring supported by the roller shaft 120.

  Although the entire body 110 is not shown, as shown in FIG. 2, for example, one end of the body 110 is supported by a pivot portion, and the other end abuts against a valve stem cap. . A through hole 112 for fixing the roller shaft 120 is formed in the body 110, and the roller shaft 120 is fitted into the through hole 112 by caulking, for example. Further, the body 110 is formed with an opening 114 having a constant length L in the axial direction, which communicates with the through hole 112.

  The inner ring roller 130 is an annular member having an inner periphery and an outer periphery, and is rotatably mounted on the outer periphery of the roller shaft 120 in the opening 114. The axial width of the inner ring roller 130 is somewhat smaller than the length L of the opening 114, and the inner diameter of the inner ring roller 130 is somewhat larger than the outer diameter of the roller shaft 120. When the roller shaft 120 is inserted into the inner circumference of the inner ring roller 130, a certain clearance S <b> 1 is formed between the inner ring roller 130 and the roller shaft 120. Preferably, a chamfer is formed at the outer peripheral corner of the inner ring roller 130.

  The outer ring roller 140 is an annular member having an inner periphery and an outer periphery, and is rotatably mounted on the outer periphery of the inner ring roller 130 in the opening 114. The width of the outer ring roller 140 in the axial direction is substantially equal to that of the inner ring roller 130, and the inner diameter of the outer ring roller 140 is somewhat larger than the outer diameter of the inner ring roller 130. When the inner ring roller 130 is inserted into the inner circumference of the outer ring roller 140, a certain clearance S2 is formed between the outer ring roller 140 and the inner ring roller 130.

  When the inner ring roller 130 and the outer ring roller 140 are attached to the roller shaft 120, an axial clearance S3 is formed between the inner wall of the opening 114 and the side surfaces of the inner ring roller 130 and the outer ring roller 140. When the inner ring roller 130 and the outer ring roller 140 are rotated around the roller shaft 120, the axial movement of the inner ring roller 130 and the outer ring roller 140 is restricted by the inner wall of the opening 114.

  In the present embodiment, the roller shaft 120 is made of a solid metal material, and a lubricating oil supply passage 122 for supplying lubricating oil along the shaft center C is formed in the roller shaft 120. Further, the roller shaft 120 is formed with one or a plurality of oil holes 124 communicating from the lubricating oil supply passage 122 to the outer peripheral surface in the radial direction. In the example shown in the figure, three oil holes 124A, 124B, and 124C are formed, the oil holes 124A and 124C are respectively communicated with both ends of the lubricating oil supply passage 122, and the oil hole 124B is connected to the lubricating oil supply passage 122. It is connected to the center. In a preferred embodiment, the diameters of the lubricating oil supply passage 122 and the oil holes 124 </ b> A to 124 </ b> C are equal, and the axial length of the lubricating oil supply passage 122 is larger than the length L of the opening 114 of the body 110.

  A lubricating oil supply passage 116 is formed in the body 110 at a position aligned with the oil holes 124 </ b> A and 124 </ b> C of the roller shaft 120. The lubricating oil supply passage 116 communicates with the oil holes 124A and 124C, respectively. Preferably, the diameter of the lubricating oil supply passage 116 is equal to the diameter of the oil holes 124A and 124C.

  A circumferential groove 132 having a constant depth in the circumferential direction is formed at the axially central portion of the inner circumference of the inner ring roller 130 so as to align with the oil hole 124 </ b> B of the roller shaft 120. Preferably, the axial length of the circumferential groove 132 is larger than the diameter of the oil hole 124B. The lubricating oil supply passage 122 and the oil hole 124B of the roller shaft 120 can forcibly supply the lubricating oil with a predetermined pressure to the outer periphery of the roller shaft 120 through the lubricating oil supply passage 116 of the body 110, and the inner ring roller Since the circumferential groove 132 of 130 and the oil hole 124 </ b> B of the roller shaft 120 communicate with each other, the lubricating oil forcibly supplied to the outer periphery of the roller shaft accumulates in the circumferential groove 132. As a result, the lubricating oil can be forcibly sufficiently supplied to the clearance S1 between the roller shaft 120 and the inner ring roller 130, and an oil film can be formed using the static pressure effect, thereby improving the sliding characteristics. be able to.

  Further, the inner ring roller 130 is formed with one or a plurality of oil holes 134 communicating from the circumferential groove 132 to the outer circumference of the shaft in the radial direction. Preferably, the diameter (cross-sectional area) of the oil hole 134 is smaller than the oil hole diameters (cross-sectional areas) of the lubricating oil supply passages 122 and 124A to C of the roller shaft 120. Can be obtained with the clearance S1, and even if the oil pressure of the lubricating oil supply passages 122 and 124A to C of the roller shaft 120 fluctuates, the fluctuation effect on the circumferential groove 132 and the oil hole 134 of the inner ring roller 130 and the clearance S1 is reduced. To do. A circumferential groove 142 having a certain depth in the circumferential direction is formed at the axially central portion of the inner circumference of the outer ring roller 140 so as to be aligned with the oil hole 134 of the inner ring roller 130. As a result, the lubricating oil forcibly supplied at a predetermined pressure through the body 110 is also accumulated in the circumferential groove 142 of the outer ring roller 140. This makes it possible to forcibly supply the lubricating oil to the clearance S2 between the inner ring roller 130 and the outer ring roller 140 sufficiently, and an oil film is formed using the static pressure effect, improving the sliding characteristics, particularly immediately after startup. This boundary lubrication state can be changed to a fluid lubrication state, and the friction at the time of starting can be reduced. Further, since the end portions of the clearances S1 and S2 are open, the lubricating oil supplied from these portions can flow, and wear powder generated when wear occurs can flow together. There is also an effect of minimizing the progress of wear.

  Since the circumferential grooves 132 and 142 formed on the inner periphery of the inner ring roller 130 and the outer ring roller 140 are formed in the circumferential direction, the oil hole 124B formed in the roller shaft 120 and the oil hole formed in the inner ring roller 130 It is not necessary to position with 134, which is preferable in terms of assembly and cost.

  The oil hole 124 </ b> B formed in the roller shaft 120 and the circumferential groove 132 formed in the inner ring roller 130, and the oil hole 134 formed in the inner ring roller 130 and the circumferential groove 142 formed in the inner circumference of the outer ring roller 140 communicate with each other. In other words, the oil holes 124B and 134 and the circumferential groove 132 may be provided in addition to the central portion in the axial direction.

  Furthermore, an oil hole 144 that supplies lubricating oil to the outer periphery of the outer ring roller 140, which is a contact surface that slides with the cam of the camshaft, may be formed, that is, a circumferential groove 142 provided on the inner periphery of the outer ring roller 140; Oil holes 144 can be provided in the radial direction so as to communicate with each other. Lubricating oil collected in a circumferential groove 142 provided on the inner periphery of the outer ring roller 140 is supplied to the outer periphery of the outer ring roller 140 through the oil hole 144. Preferably, when the diameter (cross-sectional area) of the oil hole 144 of the outer ring roller 140 is smaller than the diameter (cross-sectional area) of the oil hole 134 of the inner ring roller 130, a larger static pressure effect is obtained with the clearance S2. Even if the oil pressure of the oil hole 134 of the inner ring roller 130 fluctuates, the fluctuation influence on the circumferential groove 142, the oil hole 144, and the clearance S2 of the outer ring roller 140 is reduced. Since the ends of the clearances S1 and S2 formed between the roller shaft 120 and the inner ring roller 130 and between the inner ring roller 130 and the outer ring roller 140 are open, the hydraulic pressure is reduced to some extent, but the outer ring roller 140 is slid with the cam. By the rotation by the movement, the lubricating oil can be forcibly supplied using this centrifugal force.

  As described above, the rocker arm 100 according to the present embodiment forcibly lubricates the clearances S1 and S2 between the roller shaft 120, the inner ring roller 130, and the outer ring roller 140 from the engine through the body 110 with a certain pressure. The friction performance at the time of start-up is improved by forming the oil film using the static pressure effect. The circumferential groove 132 formed on the inner circumference of the inner ring roller 130 and the circumferential groove 142 formed on the inner circumference of the outer ring roller 140 are formed on the outer circumference side of the roller shaft 120 and the outer circumference side of the inner ring roller 130 on the opposing surfaces, respectively. Further, it may be formed on both the inner circumference and the outer circumference of the inner ring roller 130, and on both the inner circumference of the outer ring roller 140 and the outer circumference of the inner ring roller 130.

Next, a second embodiment of the present invention will be described. FIG. 5 is a schematic sectional view of a rocker arm according to the second embodiment of the present invention, and FIG. 6 is a perspective view in which a part of the roller rocker arm according to the second embodiment of the present invention is cut away. 3 and 4 are denoted by the same reference numerals, and redundant description is omitted .

  In the rocker arm 100A of the second embodiment, the lubricating oil supply passage 122 formed along the axial center C of the roller shaft 120 does not terminate in the middle as in the first embodiment, but on the end surface thereof. Moreover, it forms so that it may penetrate. That is, a through hole 136A that communicates with one end surface 137A of the roller shaft 120 is formed at the connecting portion between the lubricating oil supply passage 122 and the oil hole 124A, and the connecting portion between the lubricating oil supply passage 122 and the oil hole 124C is formed at the connecting portion. A through-hole 136B communicating with the other end surface 137B of the roller shaft 120 is formed. Accordingly, the through hole 136A, the lubricating oil supply passage 122, and the through hole 136B are continuously formed along the axis center C from one end surface 137A of the roller shaft 120 to the other end surface 137B. The diameters of the through holes 136A and 136B may be the same as the lubricating oil supply passage 122, or may be somewhat larger than that.

  The through holes 136A and 136B formed in this way are filled with plugs 138A and 138B for closing the through holes 136A and 136B, respectively. The plugs 138A and 138B are not particularly limited in material, but are made of a material that does not leak the lubricating oil in the lubricating oil supply passage 122. For example, the plugs 138A and 138B are made of a metal material such as carbon steel or stainless steel or an elastic material such as rubber. More preferably, it is configured by press-fitting a ball of a metal material having heat resistance and oil resistance. Thus, in 2nd Embodiment, the process of the roller axis | shaft 120 becomes easy compared with 1st Embodiment.

  In the above example, the through holes 136A and 136B are formed on both sides of the roller shaft 120. However, the present invention is not limited to this, and the through holes may be formed only on one end surface side. In this case, a leakage plug is inserted into one through hole.

  Furthermore, as a preferred embodiment of the present invention, in the first and second rocker arms 100 and 110A, the outer peripheral surface of the roller shaft 120, the inner peripheral surface of the inner ring roller 130, the outer peripheral surface of the inner ring roller 130, and the outer ring roller that serve as sliding surfaces. To improve wear resistance and sliding characteristics by applying surface treatment such as DLC (Diamond like carbon), IP (Ion plating), plating, etc. to any one or more of 140 inner peripheral surfaces Can do. Furthermore, the roller-type rocker arm of the first and second embodiments of the present invention is preferably combined with a lash adjuster as shown in FIG. 3A and easily supplies lubricating oil to the vicinity of the roller shaft via the lash adjuster. can do.

  Next, a preferred example of the first embodiment of the present invention will be described. The roller shaft 120 was prepared by quenching SUJ2 material (JIS G 4805), forming a lubricating oil supply passage 122 and oil holes 124A to 124C by a known processing method, and finishing polishing. . The inner and outer ring rollers 130 and 140 are made by quenching SUJ2 material (JIS G 4805), forming peripheral grooves 132 and 142 and oil holes 134 and 144 on the inner periphery, and finishing and polishing the inner and outer peripheral surfaces. did. These were assembled to a body (not shown) to produce a sliding roller rocker arm of the example.

  Comparative Example 1 in which the same material as in the example is used, the lubricating oil supply passage and the oil hole are formed in the roller shaft, and the circumferential groove and the oil hole are not formed in the inner and outer ring rollers. Comparative Example 2 in which oil holes were formed and peripheral grooves and oil holes were not formed in the inner and outer ring rollers was produced.

  The examples and comparative example 2 produced as described above were supplied with oil pressures of 0.1 MPa and 0.03 MPa to forcibly supply the lubricating oil, and in comparative example 1, the lubricating oil was supplied only by droplet lubrication, and friction was applied. Resistance and scuff resistance were evaluated. Friction resistance is measured by setting the actual engine incorporating this product on a motoring bench connected to a dynamometer that can measure friction loss of only the valve mechanism, rotating the camshaft, and measuring its driving torque. did. The measurement conditions other than the hydraulic pressure were a camshaft rotation speed of 300 rpm and a lubricating oil supply temperature of 120 ° C. Evaluation of scuffing resistance was performed by setting an actual engine in which the product of the present invention was incorporated in a motoring bench in the same manner as measuring the frictional resistance, and measuring the time until scuffing under the same conditions. In the following table, the frictional resistance is shown as a relative ratio when Comparative Example 1 is 1. Further, in the scuff resistance, Comparative Example 1 indicates that scuffing is (-), Example is that no scuffing is observed (◯), and Comparative Example 2 indicates that some scuffing is observed (Δ).

  In the rocker arm of this example, it was confirmed that the frictional resistance was reduced and the scuff resistance was improved as compared with Comparative Examples 1 and 2.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the specific embodiment, and various modifications can be made within the scope of the present invention described in the claims. Deformation / change is possible.

100: Rocker arm 110: Body (main body)
112: Through hole 114: Opening 116: Lubricating oil supply passage 120: Roller shaft 122: Lubricating oil supply passage 124: Oil hole 130: Inner ring roller 132: Circumferential groove 134: Oil hole 136A, 136B: Through hole 137A, 137B: End face 138A, 138B: Plug 140: Outer ring roller 142: Circumferential groove 144: Oil hole

Claims (7)

A rocker arm of an internal combustion engine that is installed between a cam of a camshaft and a valve stem of an intake / exhaust valve and transmits the operation of the cam to the intake / exhaust valve,
A roller shaft;
An annular inner ring roller rotatably attached to the roller shaft;
An annular outer ring roller that is rotatably attached to the outer circumference of the inner ring roller and abuts against the cam;
A roller-type rocker arm characterized in that lubricating oil is forcibly supplied to the clearance between the roller shaft and the inner ring roller, and between the inner ring roller and the outer ring roller, and an oil film is formed by a static pressure effect. The roller shaft includes a lubricating oil supply passage and one or a plurality of oil holes communicating with the outer periphery of the shaft in the axial direction from the lubricating oil supply passage;
The inner ring roller has a circumferential groove communicating with the oil hole of the roller shaft on the inner periphery and one or a plurality of oil holes communicating with the outer periphery from the groove,
2. The roller-type rocker arm according to claim 1, wherein the outer ring roller includes a circumferential groove communicating with an oil hole of the inner ring roller on an inner circumference. The outer ring roller includes a circumferential groove communicating with an oil hole of the inner ring roller and one or a plurality of oil holes communicating with the outer periphery from the groove on the inner periphery. Roller rocker arm. The roller-type rocker arm according to claim 2, wherein the lubricating oil supply passage includes a through hole that penetrates to an end surface of the roller shaft, and a leakage preventing member that prevents leakage of the lubricating oil is filled in the through hole. . The roller rocker arm according to claim 4, wherein a metal ball is press-fitted into the through hole as the leakage preventing member. 3. The roller rocker arm according to claim 2, wherein the lubricating oil supply passage has a cross-sectional area that is smaller for the inner ring roller than for the roller shaft and smaller for the outer ring roller than the inner ring roller. DLC (Diamond like carbon), IP (Ion plating), plating on one or more of the outer peripheral surface of the roller shaft, the inner peripheral surface of the inner ring roller, the outer peripheral surface of the inner ring roller, and the inner peripheral surface of the outer ring roller The roller rocker arm according to any one of claims 1 to 6, wherein any one of the surface treatments is applied.

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