CN112502806A

CN112502806A - Module for a variable lift valve mechanism of an internal combustion engine

Info

Publication number: CN112502806A
Application number: CN201910870612.9A
Authority: CN
Inventors: A·比尔曼; B·诺埃; M·施泰格瓦尔德; M·普里贝克; F·西姆塞尔
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Holding China Co Ltd
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2021-03-16

Abstract

The invention relates to a preassembled module for a variable-lift valve train of an internal combustion engine, for installation in a cylinder head of the internal combustion engine, having a base plate with at least one projecting guide plate, on which an electrically operated linear actuator is located in an inverted manner and a longitudinally guided push rod with one or two projecting adjustment fingers, which extend over the push rod, each adjustment finger having a contact surface for displacing a transverse coupling slide of a switchable valve push rod on a section remote from the push rod, wherein an inverting arm is suspended on the underside of the base plate, one side of which is in contact with an adjustment pin of the linear actuator passing through the base plate and the other side of which is in contact with the push rod for displacing the push rod in one direction, wherein a spring means is mounted on the module for displacing the push rod in the other direction of the push rod, the spring means are clamped at least indirectly between the push rod and the base plate or guide plate.

Description

Module for a variable lift valve mechanism of an internal combustion engine

Technical Field

The invention relates to a module for a variable-lift valve train of an internal combustion engine, having a push rod which is acted upon by an electric linear actuator in one direction, from which push rod project adjusting fingers, each of which has a contact surface for displacing a transverse coupling slide of a switchable valve push rod on a section remote from the push rod, wherein a spring means for displacing the push rod in its other direction is mounted on the module.

Background

Such modules with a push rod loaded by an actuator and an adjusting finger on the push rod are also referred to as electric rocker modules. An example of this is known from DE 102017101792. In the cylinder head, a common tappet with an electric actuator arranged on the end side is assigned to a row of exhaust valves of a three-cylinder internal combustion engine. Each cylinder is provided with two identically acting gas exchange valves. The push rod is reset by the force of a pressure spring arranged in the vicinity of the actuator when the actuator is not energized.

The components of the aforementioned "long" modules have to be mounted on the cylinder head in a complex manner and are arranged specifically for the respective internal combustion engine type. For this purpose, the cylinder head has a slot for guiding the tappet in the section of the camshaft bearing, through which slot a longer, delicate and difficult-to-handle tappet must be guided in the assembly situation; in a subsequent assembly, the adjusting finger is assembled on the push rod. The electric actuator is located behind the tappet in alignment and unnecessarily increases the installation space of the internal combustion engine, and furthermore the electric actuator must be separately fixed.

It is also established that the simultaneous actuation of a train of gas exchange valves requires a very high current and only a short time window can be operated here. In addition, a strong return spring device must be installed. It is completely clear that internal combustion engines with a cylinder number greater than 3 can also be considered.

Disclosure of Invention

The object of the invention is therefore to create a module which is easy to construct and which can be assembled and which can be used in a variety of ways.

According to the invention, this object is achieved by the novel features of claim 1.

Therefore, a module is proposed which is preassembled "on the outside" and which is intended for installation into the cylinder head of an internal combustion engine. The module has a base plate with at least one projecting guide plate, on which the electric linear actuator is situated upside down, wherein, on the wall of the guide plate, a push rod guided along it carries one or two projecting adjustment fingers, which extend over the push rod. Suspended on the underside of the base plate is a tilting arm (Kipparm) whose one side is in contact with the adjusting pin of the linear actuator which passes through the base plate, while the other side is in contact with the push rod for displacing the push rod in one direction. Spring means are mounted on the module for displacing the push rod in its other direction and are clamped at least indirectly between the push rod and the base plate or guide plate.

Therefore, a module is proposed which does not have the aforementioned disadvantages. Now, a module with a short structure for actuating one or two (also three) selector valve struts (exhaust or intake rows) of only one cylinder of an internal combustion engine can be supplied to the internal combustion engine completely preassembled externally and assembled there automatically "from above" or manually. The transport and handling of the module becomes simpler. Those skilled in the art will recognize that the module can now be used widely in a wide range of internal combustion engine types. Only partial assembly of the cylinder head with the module is also provided here. It is also clear that the individual modules require only little energy if the switching time window is sufficiently large.

According to a preferred development of the invention, the base plate of the guide plate with the projections, which carries the functional elements of the module, consists of a thin-walled steel plate and is produced by means of a press-bending technique. The base plate is to be formed, for example, from two simple longitudinal strips, to the center of which the actuator is fastened in a raised manner. For fastening the base plate to the cylinder head, the longitudinal strips have, for example, holes at their ends. The webs can thereby be screwed together parallel to the longitudinal wall of the camshaft or of the internal combustion engine at suitable contact points of the cylinder head, for example on the camshaft bearing bushes.

Furthermore, it is proposed that a holding plate, which also projects in one piece from the base plate, is arranged parallel to the guide plate of the base plate. A simple possibility for fastening the shaft for the tilting arm, which shaft is designed as a pin, is thus achieved. Alternatively, the invert arm may be supported at two grommets suspended from the base plate

On the tabs or only on one side.

Preferably, the flexible adjustment finger consisting of spring steel should be present as a separate component that engages with the push rod. It is contemplated that the adjustment fingers may be passed through bends formed in the adjustment fingers

Or similar structure simply suspended from the push rod. However, it is also conceivable and provided for the adjusting finger to be embodied as a one-piece component of the push rod, if appropriate.

A simple contact point for the tilting arm on the push rod is provided by the tab, which is raised in one piece from the push rod according to the proposal, with which the side of the tilting arm remote from the actuator comes into contact. The tab can be easily constructed from the push rod. Alternatively, separate contact bodies, such as bolts, pins, brake blocks or the like, are also conceivable.

The "internal" guidance of the push rod on the module is the subject of a further dependent claim. Thus, the retaining plate is located on the wall of the guide plate. The push rod is guided longitudinally in the gap between these members. The two plates can be connected to each other, for example, by pins, on which the push rod is guided by means of an elongated hole.

In this case, it is also provided that a restoring means for the plunger is integrated into the module. To this end, according to a sub-variant of the invention, an arm is erected from the aforementioned holding plate, between which arm and the bow of the push rod the helical compression spring or the set of helical compression springs is clamped. Alternatively, the resetting can also be performed electromagnetically or in another way by means of a servo device.

The respective actuating finger has a curled geometry and is therefore guided flexibly in a narrow cylinder head region toward the respective switching valve push rod.

Drawings

FIG. 1 shows a perspective front view of a module;

figure 2 shows the module installed into the cylinder head; and

fig. 3 shows a side view of the module.

Detailed Description

In the drawing, a module 1 with a short structure for a variable lift valve mechanism of an internal combustion engine is shown. The module 1 is supplied to the cylinder head 6 of the internal combustion engine and screwed there in such a way that all components, which will be described below, are completely preassembled on the module 1.

The module 1 has a base plate 2 made of steel plate, and a guide plate 3 is bent downward from the base plate 2. The base plate 2 is finally composed of two webs extending in wing-like fashion relative to one another (see in particular fig. 2), on the

ends

19, 20 of which webs there is a

joint

21, 22 in each case in the form of a hole. The module 1 is firmly screwed to a bearing region 24 of the cylinder head 6 in the vicinity of a camshaft bearing 23 via the

joints

21, 22. The module 1 thus extends parallel to the longitudinal extent of the cylinder head 6.

As can be seen from fig. 1 and 2, an electric linear actuator 4, which is inverted centrally on a guide plate 3 and protrudes with its adjusting pin 16 through the base plate 2, belongs to the module 1.

On the aforementioned guide plate 3 of the base plate 2, a push rod 7 made of a steel plate is guided in the longitudinal direction of the cylinder head 6. The push rod 7 has a principally plate-like geometry. Two adjusting fingers 8 made of spring steel spaced apart from each other are suspended into the push rod 7. These adjusting fingers extend on the outer wall of the push rod 7 and are located via an elbow 29 in a recess 27 on the upper longitudinal side 28 of the push rod 7.

As can be seen from fig. 1, the respective actuating finger 8 passes below the push rod 7 into a first extension 38, which is bent parallel thereto, from which a hook-like end piece 39 (section 9 remote from the push rod) with a contact surface 10 for the transverse coupling slide 11 of the switchable valve push rod 12 rises in a bent manner upward. The module 1 with a short structure is therefore only associated with two identically acting gas exchange valves of one cylinder of the internal combustion engine.

On the underside 13 of the base plate 2, a tilting arm 14 of the angle gauge type (see fig. 1, 3) made of steel plate is suspended. For this purpose, the holding plate 25 is opposed to the guide plate 3 of the base plate 2 in parallel. The

plates

2, 25 are bridged by a pin 26 fixed therein, on which the tilting arm 14 bears. As is best shown in fig. 3, an upper edge 15 of the tilting arm 14 is contacted by an adjusting pin 16 of the linear actuator 4. The other edge 17 of the tilting arm 14 acts on a web 30 of the push rod 7 for displacing the push rod in one direction (here the "coupling direction" from right to left).

For example, at the beginning of a coupling time window predefined for the transverse coupling sliders 11 of the two valve levers 12, the energization of the actuator 4 causes the adjusting pin 16 thereof to extend downward, as a result of which the tilting arm 14 is rotated in a clockwise direction in segments (segmentweise). The push rod 7 will thus be displaced to the left with its suspended adjustment finger 8, and the adjustment finger 8 will displace the transverse coupling slide 11 of the valve rod 12 (on the basis of a cam base circle rotation), whereby a coupling or decoupling of the two rod parts of the valve rod 12 will be achieved depending on the configuration, which need not be explained in detail in this connection.

The above-described translatory guidance of the push rod 7 on the module 1 takes place more precisely in the gap between the guide plate 3 and a holding plate 32, which is also composed of steel plate, which is firmly connected to the guide plate 3. The push rod 7 has an elongated hole 36 visible in fig. 2, in which at least one pin 37 connecting the guide plate and the holding plate 3, 32 moves.

An arm 33 projects upwardly from the holding plate 32, said arm being opposite an arch 35 which also rises upwardly from the end 34 of the push rod 7 remote from the tilting arm (see fig. 3). In the meantime, when the electric linear actuator 4 is not energized or is energized only slightly, the spring means 18 in the form of a helical compression spring is clamped as a module component for resetting the tappet 7.

It is clear that, due to the spring action of the actuating fingers 8, these can "pretension" the corresponding transverse coupling slide 11 in the valve rod 12 beyond or before the cam base circle rotates in the desired displacement, wherein this then results in the corresponding transverse coupling slide 11 "abruptly" protruding into the valve rod 12 at the beginning of the base circle.

List of reference numerals

1) Module

2) Substrate

3) Guide plate, board

4) Electric linear actuator and actuator

5) Wall(s)

6) Cylinder cover

7) Push rod

8) Adjustable shifting finger

9) Segment of

10) Contact surface

11) Transverse coupling slide block

12) Air valve compression bar

13) Lower side

14) Turnover arm

15) One edge

16) Adjusting pin

17) The other side

18) Spring device

19) End part

20) End part

21) Joint point

22) Joint point

23) Camshaft bearing bush

24) Region(s)

25) Holding plate, plate

26) Pin

27) Concave part

28) Longitudinal side

29) Elbow bend

30) Tab

31) Supporting element

32) Retaining plate

33) Arm(s)

34) End part

35) Bow-shaped element

36) Elongated hole

37) Pin

38) Extension part

39) An end piece.

Claims

1. Pre-assembled module (1) for a variable-lift valve train of an internal combustion engine for installation in a cylinder head (6) of the internal combustion engine, the module (1) having a base plate (2) which has at least one projecting guide plate (3), an electric linear actuator (4) being situated upside down on the base plate (2), and, on a wall (5) of the guide plate (3), a push rod (7) guided along it carries one or two projecting adjustment fingers (8) which extend over the push rod, each of the adjustment fingers (8) having, on a section (9) remote from the push rod, a contact surface (10) for displacing a transverse coupling slide (11) of a switchable valve lever (12), wherein a tilting arm (14) is suspended on the underside (13) of the base plate (2), one edge (15) of the tilting arm is in contact with an adjusting pin (16) of the linear actuator (4) which passes through the base plate (2), while the other edge (17) of the tilting arm is in contact with the push rod (7) for displacing the push rod in one direction, wherein a spring means (18) is mounted on the module (1) for displacing the push rod (7) in the other direction of the push rod, which is clamped at least indirectly between the push rod (7) and the base plate (2) or the guide plate (3).

2. Module according to claim 1, wherein the base plate (2) and the guide plate (3) are one-piece sheet metal stamped and bent parts, wherein the base plate (2) consists of two strips extending opposite each other, the electric linear actuator (4) being located at the contact center of the strips, wherein engagement points (21, 22), such as threaded holes, are provided on the free ends (19, 20) of the strips for connecting the module (1) with a camshaft bearing (23) or with a region (24) of the cylinder head (6) close to the camshaft bearing.

3. Module according to claim 1, wherein a retaining plate (25) opposite parallel to the guide plate (3) projects from the base plate (2) and the two plates (3, 25) are bridged by a pin (26) fixed therein, on which the flip arm (14) bears.

4. Module according to claim 1, wherein the corresponding adjusting finger (8) is a one-piece or multi-piece component of the push rod (7), wherein, in the case of a multi-piece construction of the adjusting finger, the adjusting finger is guided upwards on one of the walls of the push rod (7) and is located via a bend (29) in a recess (27) of an upper longitudinal side (28) of the push rod.

5. Module according to claim 1, wherein a tab (30) is cocked from the push rod (7), which tab is contacted by the other side of the flip arm (14) for displacing the push rod (7) in a manner loaded by an actuator.

6. Module according to claim 1, wherein the push rod (7) is guided translationally in a gap between a wall (5) of the guide plate (3) and a retaining plate (32) which is firmly connected to the guide plate (3), an arm (33) protruding from the retaining plate (32), and an arch (35) protruding from an end (34) of the push rod (7) remote from the flip arm being opposite the arm, wherein a spring means (18) configured as at least one helical compression spring is clamped between the arm (33) and the arch (35) for resetting the push rod (7).

7. Module according to claim 6, wherein the push rod (7) has an elongated hole (36) in which at least one pin (37) connecting the guide plate (3) and the retaining plate (32) moves.

8. Module according to claim 1 or 4, wherein the respective adjusting finger (8) consists of spring steel and passes below the push rod (7) into a first extension (38) which is bent parallel to the push rod, from which a hook-like end piece (39) with a contact surface (10) rises in an upwardly bent manner.