WO2017205889A1

WO2017205889A1 - Reciprocating-piston machine

Info

Publication number: WO2017205889A1
Application number: PCT/AT2017/060144
Authority: WO
Inventors: Andreas Krobath; Devaraj DORAISWAMY; Bernhard HAUSMANN; Thomas WEBERBAUER; Jürgen PICHLER
Original assignee: Avl List Gmbh
Priority date: 2016-05-31
Filing date: 2017-05-31
Publication date: 2017-12-07
Also published as: WO2017207671A1

Abstract

The invention relates to a reciprocating-piston machine, in particular an internal combustion engine (1), with a variable compression ratio, having a length adjustment device (8) which is arranged in a connecting rod (2) and can be activated by way of a switching unit (9) which is arranged in the connecting rod (2), wherein an actuating mechanism (10) is operatively connected to the switching unit (9) in the region of a connecting rod bearing (3) in order to introduce a switching pulse into the connecting rod (2). In order to make the introduction of a switching pulse into the connecting rod (2) possible in a simple way, it is provided that the actuating mechanism (10) has a transmission means (30) which is arranged in the region of the connecting rod bearing (3), and the switching unit (9) has at least one switching valve (11a, 11b) which is arranged in the connecting rod body (7) of the connecting rod (2) and the valve body (112a, 112b) of which, which can be displaced substantially in the direction of the rotational axis (3a) of the connecting rod bearing (3), can be deflected out of a closed position into an open position by way of the transmission means (30).

Description

reciprocating engine

The invention relates to a reciprocating engine - in particular an internal combustion engine - with variable compression ratio with a arranged in a connecting rod length adjustment, which is activatable with a connecting rod arranged in the switching unit, wherein for introducing a switching pulse in the connecting rod in the region of a connecting rod bearing an adjusting mechanism with the switching unit in Active compound is.

Internal combustion engines with variable compression ratio are used, for example, to increase the efficiency of the internal combustion engine in the deviating from the optimum operating ranges.

Reciprocating usually have a connecting rod, which is pivotable in a connecting rod bearing about a crank pin of the crankshaft. At the end of the connecting rod remote from the connecting rod bearing a piston pin bearing is provided. Via a piston pin, which is arranged in the piston pin bearing, the connecting rod is pivotally connected to a piston. The piston reciprocates in a cylinder between its top dead center and bottom dead center.

Length adjustment can be carried out mechanically, for example, threaded spindles and spindle nuts, or hydraulically via hydraulic chambers in the connecting rod, which can be filled via hydraulic lines from the connecting rod bearing with hydraulic medium.

As a switching unit can be understood any device that can switch the length adjustment from holding their position, to extend or shorten the connecting rod.

Switching pulse here is understood to mean the pulse coming from outside the connecting rod for switching the length adjusting device.

An actuating mechanism is needed to move the indexing unit to the desired position.

As an active compound is understood here a connection for the transmission of forces and shifts.

From DE 10 2013 113 432 AI a changeover valve unit is known, which has an actuation module with a linearly displaceable tapping element for actuation from the outside to the connecting rod. In this case, the actuation module in the connecting rod in the region of the connecting rod bearing in the direction of the piston pin bearing orderly. The tapping element is displaceable parallel to a plane in the embodiments shown. This plane is determined by axes of rotation of the piston pin bearing and the connecting rod bearing. By displacement of the tapping element hydraulic paths are released and blocked by two valves which are moved due to ramps of the tapping element.

It is not disclosed exactly how the displacement of the tap element is done. In the area in which it is arranged, the introduction of a switching pulse is difficult. It lacks an actuating mechanism that operates the tapping element from an easily accessible location.

Object of the present invention is to avoid these disadvantages and to provide a reciprocating engine with a robust and simple control mechanism for introducing a switching pulse.

This object is achieved in that the actuating mechanism comprises a transmission means arranged in the region of the connecting rod bearing and the switching unit at least one switching valve arranged in the connecting rod of the connecting rod, whose valve body displaceable in the direction of the axis of rotation of the connecting rod bearing by the transmission means from a first position - for example a closed position of the switching valve - in a second position - for example, in an open position of the switching valve - is deflected.

The transmission means is in operative connection with the deflecting element and is arranged in the region of the connecting rod bearing. The transmission means here serves to transmit forces and displacements from the deflecting element to the switching unit. This results in the advantage that the distance between the switching unit and deflecting element can be overcome and switching unit and deflecting element need not necessarily be arranged next to each other.

The adjusting mechanism preferably has a deflecting element with at least a first force application region and at least one second force application region. The first force application region and the second force application region are selectively contactable with at least one actuating device. By this deflecting element, it is possible to adjust the adjusting mechanism only by the pivotal movement of the connecting rod.

The deflecting element does not require a complicated actuating device, but rather a switching pulse can be introduced from the outside into the length adjusting device from the outside only by the own movement of the connecting rod with the actuating device. The deflection element can be realized in a particularly simple manner if it has a deflection lever.

Easy accessibility or accessibility of the deflecting element is formed when the deflecting element is arranged on a connecting rod bearing bracket and can be contacted with the actuating device in a bottom dead center of the connecting rod. The same advantage results when the actuator is arranged in a crankcase.

Here, the connecting rod has, around the connecting rod bearing, a connecting rod bearing bracket remote from the piston and a connecting rod body facing the piston.

In order to obtain the simplest possible design, it is favorable if the transmission means has a tapping unit for actuating the switching unit for the length adjusting device on a side of the connecting rod facing away from the connecting rod bearing bracket and the tapping unit has a ramp and a push element displaceable by the ramp.

It is advantageous if the deflecting element has at least one first driver connected to the transmission means, which is preferably fork-shaped, when the first driver is in engagement with the deflecting lever, and when the deflecting element has at least one second driver, which is preferably fork-shaped. The fork shape is provided in order to be able to detect the reversing lever as possible from two sides. Therefore, the lever is located between the forks and both forks act on the lever. Thus, a displacement in both directions from the driver to the lever and vice versa be transferred. The second driver is engaged with the reversing lever on the side facing away from the first driver side of the deflecting element.

A particularly simple design with few individual parts is obtained when the transmission means is designed as a slide ring and the ring slide is used to transmit the switching pulse from the connecting rod bearing bracket to the connecting rod body. Under ring slide here understands a rotatable about the connecting rod bearing annular disc which is displaceable by the deflecting element.

In order to switch a hydraulically operated length adjustment as simple as possible, it is advantageous if the switching unit has a first switching valve with a first valve body and a second switching valve with a second valve body, preferably first and second valve body are alternately deflected by the ramp. To block or release of mechanical length adjustment, it is advantageous if the switching unit is designed as a sliding wedge element.

The wedge element serves, for example, for the mechanical blocking of a rotation of threaded spindles which realize the extension or shortening of the connecting rod.

In order to obtain an embodiment with a rapidly deployable actuation from the first force application region and the second force application region, it is advantageous if the actuation device has a first actuation element and a second actuation element, wherein the first force application region with the first actuation element and the second force application region with the second actuation element optionally is contactable. As a result, the actuators can be delivered independently, and the force application areas are contacted faster. It is particularly advantageous if the actuating element are arranged linearly displaceable or rotatable on shafts.

To make the contact between actuators and force application areas low, it is advantageous if the first actuating element and the second actuating element each have a sliding surface for contacting the first force application region and the second force application region.

In order to allow a gentle engagement, the sliding surface may be concave on the actuating element.

To secure a position, it is advantageous if the adjusting mechanism has a latching element which is arranged so that against a displacement, a force acts on the transmission means.

Locking element is ball with spring and counter surface on transfer means transverse to the displacement normal to the plane in which the transfer means is arranged.

In the following, the invention will be described in more detail with reference to the non-limiting figures in several embodiments. Show it :

1 shows a connecting rod of a reciprocating piston engine according to the invention in a first embodiment in an oblique view.

Fig. 2 shows this connecting rod in a side view;

Fig. 3 shows this connecting rod in a view from below; 4 shows this connecting rod with an actuating device in a view from below.

5 shows a tapping unit of this connecting rod in a first position in a plan view;

FIG. 6 shows this tapping unit of the connecting rod in a second position in a plan view; FIG.

7 shows an actuating mechanism of the connecting rod in an oblique view;

8 is a connecting rod of a reciprocating piston engine according to the invention in a second embodiment in an oblique view.

9 shows this connecting rod in a further oblique view;

Fig. 10 this connecting rod in side view;

Fig. 11, this connecting rod in a section along the line XI - XI in Fig.

10

Fig. 12, this connecting rod in front view;

FIG. 13 shows this connecting rod in a further side view; FIG.

Fig. 14, this connecting rod in a section along the lines XIV - XIV in

Fig. 13;

Fig. 15 is a tapping unit of this connecting rod in detail in a

Tilt;

FIG. 16 shows this connecting rod in an oblique view in a section analogous to FIG. 14; FIG.

Fig. 17 and 18, a switching unit of this connecting rod in detail in

Oblique views from different sides.

In Fig. 1, a part of an internal combustion engine 1 with a variable compression ratio is shown. This has a connecting rod 2.

The connecting rod 2 is arranged in a connecting rod bearing 3 in a crank chamber 4 pivotally about a crank pin, not shown. The crank chamber 4 is the cavity around the connecting rod 2 and a crankshaft, which is bounded by a crankcase la, wherein the crankshaft is not shown and the crankcase only schematically below (from a piston, not shown turned away) of the connecting rod 2 is shown. The connecting rod 2 has, in addition to the connecting rod bearing 3, a piston pin bearing 5. With a piston pin, the connecting rod 2 is pivotally connected to a piston which is arranged in a cylinder back and forth. By the axes of rotation 3a, 5a of the cylinder-jacket-shaped bearings 3, 5 is a plane ε. A median plane δ is normally arranged on the axes of rotation 3a, 3b of the bearings 3, 5. A longitudinal axis 2a of the connecting rod 2 is the line of intersection of the central plane δ and the plane ε.

The connecting rod 2 shown is divided in the connecting rod bearing 3 in a connecting rod bearing bracket 6 and in a Pleuelkörper 7. The Pleuelkörper 7 is facing the piston pin bearing 5 on the connecting rod 2 and the connecting rod bearing bracket 6 is disposed away from the piston pin bearing 5.

To realize a variable compression ratio, a length adjustment device 8 is provided in the connecting rod 2. This length adjustment device 8 can be hydraulically or mechanically actuated. In this case, the connecting rod 2 changes its length along its longitudinal axis 2a through the length adjustment device 8.

For controlling the length adjustment device 8, a switching unit 9 is arranged in the connecting rod body 7. The switching unit 9 is actuated via an adjusting mechanism 10. This is arranged in the region of the connecting rod bearing 3 and serves to transmit a switching pulse from the connecting rod bearing bracket 6 in the connecting rod 7 to the switching unit 9. The switching unit 9 is in the embodiments shown in each Pleuelkörper 7, the piston pin bearing 5 facing in the vicinity of the connecting rod bearing 3 arranged.

The adjusting mechanism 10 has a tapping unit 20, a transmission means 30 and a deflecting element 50. The deflecting element 50 can be contacted with an actuating device 60. The actuating device 60 acts on a first force application region 51 or on a second force application region 52 of the deflection element 50.

In the figures, the connecting rod 2 is in each case in its bottom dead center, that is, that the piston occupies its smallest distance to the crankshaft.

The deflecting element 50, as shown in FIG. 3, has the first force application region 51. This is located on a first driver 53, which is fork-shaped. The second force application region 52 is arranged on the opposite side of the central plane δ on a second carrier 54. The second driver 54 also has a fork shape. Between the fork tines of the driver 53, 54, a reversing lever 55 is arranged, the order a fulcrum 55a is rotatable between a first lever position and a second lever position. The second driver 54 is displaceable.

A first actuating element 61 can engage the first force application region 51, and a second actuation element 62 can engage the second force application region 52. The first actuator 61 and the second actuator 62 are part of the actuator 60 shown in FIG. The actuators 61, 62 are either slidable along a shaft 63, or rotatable about the shaft 63 out of engagement. The actuating elements 61, 62 each have a curved sliding surface 61a, 62a for the respective driver 53, 54.

In the illustrated embodiment, the switching unit on two switching valves I Ia, I Ib, with which a first and second hydraulic line 110a, 110b in the connecting rod body 7 of the connecting rod 2 can be closed or opened. By means of the hydraulic lines 110a, 110b, reference numerals 109 exemplarily indicate hydraulic chambers, for example, between two telescopically displaceable connecting rod parts. The switching valves 11a, 11b have valve bodies 112a, 112b loaded by valve springs 11a, 111b, which open or close the cross section of a first or second hydraulic line 110a, 110b. As shown in detail in FIGS. 5 and 6, the tapping unit 20 has a ramp 21 on the transmission means 30 and two pushers 22a, 22b. The thrust elements 22a, 22b formed by, for example, cylindrical push pins 122a, 122b are displaceably mounted in guide bores 123a, 123b in the connecting rod 2 and are in touching contact with the valve bodies 112a, 112b. The push pins 122a, 122b may be rounded or conically shaped in the region of the end facing the annular slide 31 in order to reduce the actuating forces. As an alternative to two-part versions, it is also possible to carry out the valve body and the sliding pin in one piece. The guide bores 123a, 123b are arranged substantially parallel to the axes of rotation 3a, 5a of the bearings 3, 5 of the connecting rod 2.

By the reference numerals 124a, 124b are arranged in the hydraulic lines 110a, 110b check valves which prevent unwanted back flow of the hydraulic oil from the hydraulic chambers 109.

In the illustrated embodiment, the transmission means 30 is designed as an annular slide 31. In Fig. 7, the adjusting mechanism 10 is shown in detail. In this case, the ramp 21 of the tapping unit 20 is arranged on the annular slide 31. The ramps 21 of the tapping unit 20 can be arranged on either side of an elevation 20a (FIG. 5, 6) or a depression 20b (FIG. 7). Both with one Survey 20a, as well as with a recess 20b axial deflection of the thrust elements 22a, 22b and thus actuation of the switching valves I Ia, I Ib can be effected by turning the annular slide 31 via the ramp 21.

At the annular slide 31, the first driver 53 is arranged. The first driver 53 and the annular slide 31 are made in one piece. The driver 53 is located on the annular slide 31 with respect to the ramp 21, on the side facing away from the connecting rod 7 side. A main body 56 of the deflecting element 50 is fixedly connected to the connecting rod 2. In the embodiment shown, the second driver 54 is slidably mounted on this base body 56.

As a result of the rotation of the annular slide 31, at least one thrust element 22a or 22b is pushed from the ramp 21 of the tapping unit 20 by the annular slide 31 in its axial direction (in the direction of the longitudinal axis 22 ^'of the thrust element 22a, 22b) from a first position to a second position , The provision is made by means of the restoring force of the valve springs li la, 111b.

Claims

PATENT CLAIMS

1. Reciprocating piston engine - in particular an internal combustion engine (1) - with a variable compression ratio with a length adjustment device (8) arranged in a connecting rod (2), which can be activated with a switching unit (9) arranged in the connecting rod (2), for the introduction of a switching pulse in the connecting rod (2) in the area of a connecting rod bearing (3) is an adjusting mechanism (10) in operative connection with the switching unit (9), characterized in that the adjusting mechanism (10) has a transmission means (30) arranged in the area of the connecting rod bearing (3) and the switching unit (9) has at least one switching valve (I Ia, I Ib) arranged in the connecting rod body (7) of the connecting rod (2), the valve body (112a, 112b) of which can be moved essentially in the direction of the axis of rotation (3a) of the connecting rod bearing (3). can be deflected from a first position into a second position by the transmission means (30).

2. Reciprocating piston machine according to claim 1, characterized in that the transmission means (30) has a tapping unit (20) for actuating the switching unit (9) for the length adjustment device (8) on a side of the connecting rod (2) facing away from the connecting rod bearing bracket (6). .

3. Reciprocating piston machine according to claim 2, characterized in that the tapping unit (20) has at least one ramp (21) with which at least one valve body (112a, 112b), preferably from a closed position to an open position, particularly preferably against the force of a valve spring (l i la, 111b), can be deflected.

4. Reciprocating piston machine according to claim 3, characterized in that a thrust element (22a, 22b) which can be displaced by the ramp (21) is arranged between the ramp (21) and at least one valve body (112a, 112b).

5. Reciprocating piston machine according to one of claims 1 to 4, characterized in that the switching unit (9) has a first switching valve (I Ia) with a first valve body (112a) and a second switching valve (I Ib) with a second valve body (112b). , wherein preferably the first (112a) and second valve body (112b) can be deflected alternately by the ramp (21).

6. Reciprocating piston machine according to one of claims 1 to 5, characterized in that the adjusting mechanism (10) has a deflection element (50) with at least a first force application area (51) and at least one second force application area (52), and that the first force application area (51) and the second force application area (52) can be selectively contacted with at least one actuating device (60).

7. Reciprocating piston machine according to claim 6, characterized in that the deflection element (50) has a deflection lever (55).

8. Reciprocating piston machine according to claim 6 or 7, characterized in that the deflection element (50) is arranged on a connecting rod bearing bracket (6) and can be contacted with the actuating device (60) at a bottom dead center of the connecting rod (2).

9. Reciprocating piston engine according to one of claims 6 to 8, characterized in that the actuating device (60) is arranged in a crankcase (la).

10. Reciprocating piston machine according to one of claims 1 to 9, characterized in that the transmission means (30) is in operative connection with the deflection element (50).

11. Reciprocating piston machine according to one of claims 6 to 10, characterized in that the deflection element (50) has at least one first driver (53) connected to the transmission means (30), which is preferably fork-shaped.

12. Reciprocating piston machine according to one of claims 6 to 11, characterized in that the deflection element (50) has at least one second driver (54), which is preferably fork-shaped.

13. Reciprocating piston machine according to one of claims 1 to 10, characterized in that the transmission means (30) is designed as an annular slide (31) and the switching pulse can be transmitted from the connecting rod bearing bracket (6) to the connecting rod body (7) by means of the annular slide (31).

14. Reciprocating piston machine according to one of claims 6 to 13, characterized in that the actuating device (60) has a first actuating element (61) and a second actuating element (62), the first force application area (51) being connected to the first actuating element (61) and the second force application area (52) can be selectively contacted with the second actuating element (62).

15. Reciprocating piston machine according to claim 14, characterized in that the first actuating element (61) and the second actuating element (62) each has a sliding surface (61a, 62a) for contacting the first force application area (51) and the second force application area (52).