Shifting gate arrangement and method for the production thereof

Abstract

A shifting gate arrangement, and a method of production thereof, having shifting gates, which are adjustable in a spatial direction, for actuating connecting rod adjustment provisions, which are integrated in connecting rods, for the purpose of changing the length of the respective connecting rod. A sheet metal support frame is mounted so as to be displaceable to and fro in the one spatial direction. The shifting gates are fixedly connected to the support frame and are designed as a cast part or sintered part.

Claims

1. A shifting gate arrangement comprising: shifting gates, which are each adjustable for actuating an adjustment rod of a respective connecting rod and thereby consequently changing a length of the respective connecting rod, wherein the shifting gates are fixedly connected to a support frame, wherein the support frame is provided with a plurality of integral embossments for pre-positioning the respective shifting gate prior to welding the respective shift gate to the support frame, wherein the respective integral embossment has a positive projection for interacting with a matching negative projection of the respective shifting gate to limit axial or rotational displacement of the respective shifting gate on the support frame prior to welding the respective shift gate to the support frame, wherein for each shifting gate, the negative projection of the shifting gate protrudes into a hollow portion of the shifting gate, and wherein the shifting gates are fixedly connected to the support frame by welded joints.

2. The shifting gate arrangement as claimed in claim 1, wherein the support frame is composed of steel sheet.

3. The shifting gate arrangement as claimed in claim 1, wherein the respective shifting gate is a precision cast part, a steel precision cast part, a sintered part, or a steel powder sintered part.

4. The shifting gate arrangement as claimed in claim 1, wherein the support frame has two first frame portions which are arranged parallel to each other and run in the spatial direction, and a plurality of second frame portions which are arranged transversely with respect to said first frame portions and are connected to the first frame portions, wherein the shifting gates are fixedly connected to the support frame in the region of the first frame portions.

5. The shifting gate arrangement as claimed in claim 4, wherein an attachment on one of the first frame portions of the support frame has a form-fitting portion for engagement with an adjustment means for displacing the support frame, wherein the attachment on said one of the first frame portions is produced by deformation during production of the support frame.

6. The shifting gate arrangement as claimed in claim 1, wherein the support frame has a receptacle for positioning the support frame in a machining position of the shifting gates.

7. The shifting gate arrangement as claimed in claim 1, wherein the support frame is mounted in a stationary oil scraper arrangement in a manner displaceable in the direction.

8. The shifting gate arrangement as claimed in claim 1, wherein the shifting gates are a cast part or sintered part.

9. The shifting gate arrangement as claimed in claim 1, wherein each positive projection has a smaller diameter than the matching negative projection.

10. The shifting gate arrangement as claimed in claim 1, wherein each positive projection is a solid circular protrusion.

11. The shifting gate arrangement as claimed in claim 1, wherein the matching negative projections on each shifting gate are oriented to key the shifting gate on the positive projections of the support frame.

12. The shifting gate arrangement as claimed in claim 1, wherein each positive projection extends upwardly from a shifting gate mounting surface on the support frame toward a respective one of the shifting gates.

13. A method for producing a shifting gate arrangement for a motor vehicle, said method comprising: a. producing a support frame from sheet metal, b. producing shifting gates by either casting or sintering, c. pre-positioning each of the shifting gates on the support frame by positioning integral embossments of the support frame, which are each provided in the form of a positive projection, within matching negative projections of a respective shifting gate to limit axial or rotational displacement of the respective shifting gate on the support frame prior to welding the respective shift gate to the support frame, wherein for each shifting gate, the negative projection of the shifting gate protrudes into a hollow portion of the shifting gate, d. welding the shifting gates to the support frame, e. machining shifting surfaces on the shifting gates, said shifting surfaces being arranged parallel in a plane which is arranged perpendicularly to a spatial direction in which the shifting gates are adjustable during operation.

14. The method as claimed in claim 13, wherein the support frame is produced from a steel sheet, and the shifting gates are produced from a precision casting, a steel precision casting, or are produced by sintering.

15. The method as claimed in claim 13, further comprising forming the embossments for pre-positioning the shifting gates during production of the support frame from the sheet metal.

16. The method as claimed in claim 13, wherein the shifting gates and the support frame are welded by laser welding.

17. The method as claimed in claim 13, wherein the shifting surfaces of the shifting gates are machined by grinding.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) An exemplary embodiment of the invention for clarifying the shifting gate arrangement and the method for producing said shifting gate arrangement is illustrated in the drawing and explained in more detail in the description below. The invention is not restricted here to the exemplary embodiment described.

(2) In the drawing:

(3) FIG. 1 shows the shifting gate arrangement in a three-dimensional illustration,

(4) FIG. 2 shows the shifting gate arrangement according to FIG. 1 in an exploded illustration,

(5) FIG. 3 shows the shifting gate arrangement according to FIG. 1 and an oil scraper arrangement, illustrated in an exploded illustration,

(6) FIG. 4 shows the arrangement according to FIG. 3 in an assembled state,

(7) FIG. 5 shows the arrangement according to FIG. 4 with an additional illustration of a servo motor for displacing the support frame and two connecting rods, which are assigned to different cylinder blocks, of a boxer engine.

DETAILED DESCRIPTION OF THE INVENTION

(8) FIGS. 1 and 2 illustrate the shifting gate arrangement 1. The latter has a support frame 2 composed of steel sheet, and six shifting gates 3 composed of steel precision casting, which are fixedly connected to the support frame 2.

(9) The support frame is designed as a punched part. It has two frame portions 4 which are arranged parallel to each other and run in a spatial direction X, and two frame portions 5 which run transversely with respect to said frame portions 4, specifically in the spatial direction Y, and are connected to the frame portions 4. The shifting gates 3 are fixedly connected to the support frame 2 in the region of the frame portions 4.

(10) The three shifting gates 3 which are connected to the one frame portion 4 serve for shifting three connecting rods, which are assigned thereto, of a first row of cylinders of an internal combustion engine designed as a boxer engine, and the three shifting gates 3 which are connected to the other frame portion 4 serve for shifting three associated connecting rods of a second row of cylinders of the boxer engine. The latter is therefore a six-cylinder boxer engine.

(11) It can be gathered in particular from the illustration of FIG. 2 that the support frame 2 has two embossments 6, which are designed as pin embossments, in the connecting region to the respective shifting gate 3, wherein the embossments 6 are arranged at a distance from each other. The embossments 6 therefore constitute elevations in relation to the support frame 2 in the Z direction and are spaced apart in the Y direction. For interaction of the respective shifting gate 3 with said embossments 6 on the support frame 2, the shifting gate 3 is provided with matching recesses 7, of which only one recess 7 can be seen in the respective shifting gate 3.

(12) The respective shifting gate 3 is pre-positioned in the region of the embossments 6 and recesses 7, and then the shifting gate 3 is fixedly connected to the support frame 2 by laser welding.

(13) The one of the two frame portions 4 is provided in the region of a free end with an attachment 8 of angled design during the production of the support frame 2. Said attachment is of U-shaped design and constitutes a form-fitting portion for the engagement of an adjustment means 9 (see FIG. 3). By means of said adjustment means 9, the support frame 2 and, accordingly, also the shifting gates 3 can be moved in the X direction and in the opposite direction thereto, for the purpose of changing the position of the shifting gates 3 in said spatial direction X and in the opposite direction thereto.

(14) Said one frame portion 4 furthermore has a receptacle 10 for positioning the support frame 2 in a machining position of the shifting gates 3. Said receptacle 10 is designed as an elongated hole and constitutes the zero point for machining in the X direction.

(15) FIGS. 3, 4 and 5 illustrate the interaction of the shifting gate arrangement 1 with an oil scraper arrangement 11, furthermore of a servomotor 12 with the adjustment means 9, and also the arrangement of two connecting rods 13 which are assigned to cylinders of different rows of cylinders of the boxer engine and the length of which is adjustable.

(16) The oil scraper arrangement 11 has a plurality of oil scrapers 14 per cylinder or per respective connecting rod 13, specifically three oil scrapers 14 per connecting rod 13, which are effective adjacent to a crankshaft-side connecting rod eye 15 of the connecting rod 13 and strip off excess oil located there from the connecting rod 13 and conduct the oil downward to an oil pan or an oil sump.

(17) The shifting gate arrangement 1 is mounted in the oil scraper arrangement 11 and is displaceable with respect to the latter exclusively in the X direction, because of action via the servomotor 12.

(18) As can be gathered from the illustration of FIG. 5, the respective connecting rod is of multi-part design, with a connecting rod portion 16 which has the large connecting rod eye 15, and also a connecting rod portion 17 which is mounted in said connecting rod portion 16 so as to be pivotable about an X axis and has a piston-side, eccentric, small connecting rod eye 18. An adjustment mechanism 19 with two adjustment rods 20 is effective between the two connecting rod portions 16 and 17. Said adjustment rods 20 are mounted in bearing axes 22 of the connecting rod portion 17 and are extendible out of the connecting rod portion 16. Part of the adjustment mechanism 19 furthermore forms a pin 23 which is arranged in the connecting rod portion 16 in the region of the connecting rod eye 15 and is displaceable to and fro in the X direction. Said pin 23 is movable to and fro by means of the associated shifting gate 3. For this purpose, the respective shifting gate 3 has a gate portion 24 and a gate portion 25. If the pin 23 makes contact with the gate portion 24, the pin 23 is displaced in the X direction because of the contour of the gate portion 24 and leads to a change in length of the connecting rod 13 in the one direction. If, by contrast, the support frame 2 is displaced counter to the X direction by means of the servomotor 12, the other gate portion 25 of the shifting gate 3 makes contact with the pin 23 and pushes the latter back again such that, as a result, the connecting rod length changes in the opposite direction.

(19) Specifically, during the displacement of the pin 23 in the X direction, the one adjustment rod 20 is extended while the other adjustment rod 20 is at the same time retracted. During extension of the one adjustment rod 20, the connecting rod portion 17 is pivoted in the manner of a tilting lever and therefore so too is the eccentric connecting rod eye 18, such that the connecting rod length changes, for example becomes greater. If the pin 23 is displaced again counter to the X direction, this movement causes the other adjustment rod 20 to be hydraulically extended while the one adjustment rod 20 is retracted at the same time, and therefore the connecting rod portion 17 recedes and therefore so too does the eccentric connecting rod eye 18, and therefore the connecting rod length changes again in the opposite direction, and therefore, according to the example, is reduced. The pivoting directions of the connecting rod portion 17 are indicated with the double arrow 21.

(20) The shifting gate arrangement 1 is produced as follows:

(21) The support frame 2, which is formed from steel sheet, is produced during design of the embossments 6 for pre-positioning the shifting gates 3. Independently thereof, the shifting gates 3 are produced by steel precision casting, with the recesses 7 serving for the pre-positioning being formed in the shifting gates 3. The shifting gates 3 are then pre-positioned on the support frame 2. The shifting gates 3 are subsequently welded to the support frame 2 by means of laser welding. Machining then takes place, specifically the grinding of the gate portions 24 and 25, which have the function of shifting surfaces, of the shifting gates 3 that are arranged parallel to the Y-Z plane. The surfaces of the gate portions 24, 25 that are arranged parallel to the Y-Z plane are therefore machined after the laser welding. The receptacle 10 which is designed as an elongated hole is provided as a zero point for the machining in the X direction.

(22) During the machining of the shifting gates 3 composed of the steel precision casting, a combination of calibration of the unfinished casting contour, said calibration being carried out in the region of the shifting surfaces 24, 25 during the production of the shifting gate 3, and finish machining of the partial surfaces by means of grinding is therefore provided.

LIST OF REFERENCE NUMBERS

(23) 1 Shifting gate arrangement 2 Support frame 3 Shifting gate 4 Frame portion 5 Frame portion 6 Embossment 7 Recess 8 Attachment 9 Adjustment means 10 Receptacle 11 Oil scraper arrangement 12 Servomotor 13 Connecting rod 14 Oil scraper 15 Large connecting rod eye 16 Connecting rod portion 17 Connecting rod portion 18 Small connecting rod eye 19 Adjustment mechanism 20 Adjustment rod 21 Pivoting directions 22 Bearing axis 23 Pin 24 Gate portion 25 Gate portion