JPH0227180Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-load rocker arm made of a press-formed metal plate.

Particularly in diesel engines and other large engines, heavy duty rocker arms are usually made by casting or forging in order to obtain the necessary high strength. Cast or forged construction has been required in the main body portion of the rocker arm below the rocker arm shaft where space is limited to provide sufficient strength. For example, diesel engines have higher cylinder pressures and are subject to greater other forces than smaller gasoline engines, requiring greater strength in these areas.

The purpose of the present invention is to provide a high-load rocker arm that is lightweight and has greater strength in the lower part of the rocker arm shaft, such as is used to operate the intake and exhaust valves and mechanically operated fuel injectors of diesel engines. be.

The invention basically provides a pressed rocker arm consisting of two pressed metal strips or plates each having two wide layer sections connected by a narrow web section. The wide layer portions are folded back around the web portion and are disposed in adjacent relationship to form the main body portion of the rocker arm. The web portion thus forms a loop portion that supports the pushrod screw and stem pad. The wide layer portions of one metal piece or plate have their respective inner surfaces adjacent to the outer surfaces of the wide layer portions of the other metal piece or plate, and the inner surfaces of the wide layer portions of the other metal piece or plate are be placed adjacent to each other. These four layers are secured together, for example by rivets, and provide the necessary strength to the main body of the rocker arm without adding excessive weight.
Furthermore, the wide layer portion of the second metal strip or plate may optionally extend to the vicinity of the loop portion of the first metal strip or plate if greater strength is required in the outer portion of the rocker arm. It can be shaped like this.

Other features and advantages of the invention will become apparent from the following description of a preferred embodiment, taken in conjunction with the accompanying drawings.

In FIG. 1, a rocker arm arrangement for a diesel engine is designated generally at 10. The rocker arm device is located at the cylinder head 12 of the engine.
Two bearing blocks 14 are disposed on the cylinder head 12 and support a rocker arm shaft 16, and lubricating oil is supplied to the rocker arm shaft 16 through a suitable passage 18. . A central rocker arm 20 mounted on the rocker arm shaft 16 operates a mechanically actuated fuel injector via a stem 22, while outer rocker arms 24 and 26 operate a lower engine cylinder via valve stems 28 and 30. Activate the supply and exhaust valves.

The rocker arm 20 for actuating the fuel injector is shown in more detail in FIGS. 2-5. The rocker arm 20 includes a first pressed metal piece or plate 32 that has a generally bowtie shape when flat. The metal strip or plate 32 has two wide end or layer sections 34 and 36.
, whose ends or layer sections are connected by a narrow web section 38 . The first metal strip or plate 32 has a web portion 38 that is folded back so that the inner surfaces of the wide layer portions 34 and 36 abut each other and that is sized or perforated to form a loop portion 40. Wide layer part 34
and 36 have grooves 42 and 44 aligned with each other to form an oil passageway 46 which communicates with a short vertical groove forming a short vertical passageway 48 adjacent the loop portion 40. There is. The upper portion of the web portion 38 is above the passage 48 and the loop portion 40
It is skewered to close it. The wide layer portions 34 and 36 also include grooves 50 and 52 that align with each other to form an oil passageway 54.
extends in the opposite direction to the passage 46. Furthermore, in the lower portions of the wide layer portions 34 and 36,
Intermediate circular openings 56 and 58 are provided through which the rocker arm shaft 16 extends.

Locker arm 20 also includes a second pressed metal piece or plate 60 that has a generally bowtie shape when flat. metal piece or plate 60
has two wide end or layer sections 62 and 64 connected by a narrow web section 66. The second metal piece or plate 60 has a loop portion 68
and the first metal piece or plate 32
The wide layer portions 62 and 64 are folded so as to be in contact with the outer surfaces of the wide layer portions 34 and 36. The loop portion 68 is the wide layer portion 3
4 and 36 cooperate to form an opening that is drilled and threaded to become a threaded hole 70, as shown in FIG. The wide layer portions 62 and 64 have outwardly extending circular flanges 72 and 7.
4, the flanges forming intermediate circular openings that align with circular openings 56 and 58 in layer sections 34 and 36 of first metal strip or plate 32. These openings are fitted with bronze bushings or sleeves 76.
is press-fitted to pivot the rocker arm 20 onto the shaft 16. The bush or sleeve 76 is
As shown in FIG. 2, an opening 78 communicating with the oil passage 46 and an opening 80 (see FIG. 5) along a groove 82 communicating with the oil passage 54 are provided. These openings and grooves receive lubricating oil from the rocker armshaft 16, which has a longitudinally disposed hole therein, and then transfer the lubricating oil to the loop portion 40 and the threaded hole 7.
Supply to 0. Loop portion 40 receives an engagement member or pad 84 having its shank 85 press-fit therein, and lubricating oil from passages 46 and 48 engages the upper end surface of fuel injector stem 22. is supplied to the lower end surface of the

Further, an engaging member or screw 8 is provided in the screw hole 70.
6 threaded shank 88 is screwed together and its rounded end 90 engages the upper end surface of the bushing rod. Screw 86 is of conventional design and includes a radial passage 9 communicating with central passage 96 for supplying lubricating oil from passage 54 to the upper end surface of the push rod.
It has an annular groove 92 having a diameter of 4. screw 86
The upper end may be provided with a hexagonal recess or equivalent means for receiving a tool for adjusting the screw up or down relative to the locker arm, and when the screw is properly adjusted, it will engage the locking nut 98. is held in position by.

The wide layer sections 34, 36 and 62, 64 of the pressed metal strips or plates 32 and 60 can be joined together by any suitable means. In the case shown, three rivets 1 are used for this purpose.
00 is used. Since the pad 84 end of the rocker arm 20 that engages the fuel injector stem is subject to high pressure and requires high strength, the wide layered portions 62 and 64 of the metal strip or plate 60 provide strength and stiffness. The loop portion of the metal piece or plate 32 is extended to increase the length of the metal strip or plate 32. When making rocker arms by other methods, brazing is performed to increase strength and seal the oil passage openings. This is done before the parts are assembled.

A rocker arm 24 for pushing a valve stem 28 of an intake or exhaust valve is shown in FIG.
In this figure, the engaging members assembled to both ends of the arm are omitted. The rocker arm 24 also has a first press-formed metal piece or plate 102 and a second press-formed metal piece or plate 102.
It consists of a press-formed metal piece or plate 104. The difference between the rocker arms 20 and 24 from the point of view of the present invention is that the wide layer portion of the second metal piece or plate 104 does not extend to the loop portion of the first metal piece or plate 102, and the It is located at a point that extends to the vicinity of the opening. This is because the rocker arm end forces experienced near the valve stem 28 or 30 are less than the forces required at the fuel injector stem 22. As a result, the wide layer portion of the second press-formed metal piece or plate 104 is shortened to reduce the overall weight of the rocker arm. Of course, such construction may be modified to suit the strength and stiffness requirements of the individual rocker arms and to minimize weight.

[Brief explanation of the drawing]

Fig. 1 is a partial perspective view of an engine using the rocker arm according to the present invention, Fig. 2 is a side view partially showing the center rocker arm in Fig. 1 in cross section, and Fig. 3 is a plan view of Fig. 2. , FIGS. 4 and 5 are cross-sectional views taken along lines 4-4 and 5-5 in FIG. 2, respectively, and FIG. 6 is a side view of another rocker arm shown in FIG. 1, showing some parts. is omitted. DESCRIPTION OF SYMBOLS 10... Locker arm device, 12... Cylinder head, 16... Locker arm shaft, 20... Locker arm, 22... Fuel injector stem, 2
4, 26... Locker arm, 28, 30... Valve stem, 32... First metal piece or plate, 34, 36... Wide layer portion, 38... Web portion, 40... Loop portion, 56, 58... Opening, 60... Second metal piece or plate, 62, 64... Wide layer portion, 66... Web portion, 68... Loop portion, 70... Screw hole, 72, 7
4...flange, 100...fixing means.

Claims (1)

[Scope of utility model registration request] first openings 56, 58 whose respective inner surfaces are adjacent to each other and which receive the rocker armshaft 16;
first wide layer portions 34 having respective identical ends connected by a first narrow loop portion 40 and terminating with opposite ends adjacent with respect to the aperture; a first press-formed metal plate 32, 102 having a surface adjacent the outer surface of the first layer portion 34, 36 and having a second aperture aligned with the aperture; and a second wide layer section 6 whose identical ends opposite to said first loop section 40 with respect to said opening are joined to form a second loop section 68 .
a second press-formed metal plate 60, 104 comprising 2, 64 and means 1 for securing said first layer portions 34, 36 and said second layer portions 62, 64 to each other;
00. A high-load rocker arm used for an internal combustion engine, characterized by comprising: