Drive engine for vehicle

Abstract

A drive engine for a vehicle has at least two cylinders (2a, 2b) aligned with each other and slidably engaged by respective pistons (7a, 7b), each piston being connected to a crankshaft (8) by insertion of a connecting rod (10, 13) and delimited by a free surface (19) having a first width (L1) measured parallel to an axis of rotation (9) of the crankshaft (8), the first width (L1) is smaller than a second width (L2) measured transversely to the first width (L1).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the priority of Italian Patent Application No. 102023000018096 filed on September 4, 2023, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The invention relates to a drive engine for a vehicle.

[0004] Specifically, the present invention relates to a type of drive engine, which includes: a crankshaft, which is mounted to rotate around a rotation axis; at least one cylinder group, which in turn includes at least two cylinders aligned with each other in a direction parallel to the rotation axis of the crankshaft; a piston, which is engaged in each cylinder in a sliding manner; and at least one connecting rod, which is interposed between each piston and the crankshaft to convert the linear reciprocating motion of the piston along the associated cylinder into the rotational motion of the crankshaft. Background Art

[0005] Due to the cylindrical shape of the pistons, the drive engines for vehicles of the above-mentioned known type have some disadvantages, mainly arising from the relatively high longitudinal footprint of the cylinder group and the associated piston group measured parallel to the axis of rotation of the crankshaft. Summary of the invention

[0006] The object of the present invention is to provide a drive engine for a vehicle which does not have the above-mentioned disadvantages and which can be produced simply and inexpensively.

[0007] According to the present invention, there is provided a drive engine for a vehicle as described in the accompanying claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The invention will now be described with reference to the accompanying drawings, which show non-limiting examples of embodiments of the invention, in which:

[0009] Figure 1 is a schematic perspective view of a preferred embodiment of a driving engine for a vehicle of the present invention;

[0010] Figure 2 and Figure 3 yes Figure 1 Two schematic perspective views of details of a drive engine with some parts removed for clarity;

[0011] Figure 4 and Figure 5 yes Figure 2 and Figure 3 two schematic side views of details of a device with some parts removed for clarity;

[0012] Figure 6 yes Figure 2 and Figure 3 a schematic perspective view of a cross section of a component of a detail; and

[0013] Figure 7 yes Figure 6 Schematic side view of a detail of a , with some parts removed for clarity. DETAILED DESCRIPTION

[0014] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 , reference numeral 1 denotes overall a drive engine for a vehicle, which in this case comprises twelve cylinders 2 arranged according to two cylinder banks 3 , 4 placed side by side.

[0015] In this case, the cylinder banks 3 , 4 comprise six cylinders 2 which are aligned with one another in a direction 5 , have respective longitudinal axes 6 which are parallel to one another and are joined in a sliding manner by respective pistons 7 .

[0016] The piston 7 moves in a linear reciprocating motion along the associated cylinder 2 by a thrust generated by a chemical reaction generated by the combustion of fuel and comburent inside the cylinder 2 .

[0017] The reciprocating linear motion of the piston 7 along the associated cylinder 2 is converted into a rotational motion of a crankshaft 8 which is mounted to rotate about an axis of rotation 9 parallel to the direction 5 .

[0018] The piston 7 (hereinafter denoted by 7a) associated with the cylinder 2 (hereinafter denoted by 2a) of the cylinder group 3 is connected to the crankshaft 8 by the insertion of a corresponding connecting rod 10, each connecting rod 10 extending between two rotation axes 11, 12 parallel to each other and parallel to the axis 9, and its axis 11 is the rotation axis of the connecting rod 10 relative to the associated connecting rod pin 8a of the crankshaft 8, and the axis 12 is the rotation axis of the connecting rod 10 relative to the associated piston 7a.

[0019] The piston 7 (hereinafter denoted 7b) associated with the cylinder 2 (hereinafter denoted 2b) of the cylinder group 4 is connected to the crankshaft 8 by the insertion of a corresponding connecting rod 13, each connecting rod 13 extending between two rotation axes 14, 15 parallel to each other and to the axis 9, and its axis 14 is the rotation axis of the connecting rod 13 relative to the corresponding connecting rod 10, and its axis 15 is the rotation axis of the connecting rod 13 relative to the associated piston 7b.

[0020] When each connecting rod 13 is directly coupled to a corresponding connecting rod 10 , the connecting rods 10 , 13 in each pair of connecting rods 10 and 13 connected to each other are substantially coplanar with each other, extend substantially in a single receiving plane P, and therefore have a relatively limited footprint in direction 5 .

[0021] Each cylinder 2 a , 2 b is delimited by a side wall 16 comprising two portions 17 having a semi-cylindrical shape opposite to one another and two portions 18 obtained between these portions 17 having a flat shape opposite to one another.

[0022] according to Figure 6 and Figure 7 As shown, each piston 7a, 7b is delimited by a free face 19 facing the relative cylinder 2a, 2b and further by a side wall 20 comprising two portions 21 of semi-cylindrical shape opposite one another and two portions 22 of flat shape opposite one another obtained between these portions 21.

[0023] The wall 20 is undercut so as to have two cavities 23 opposite one another, obtained at least at the portion 22 , in particular at the portion 21 and at the portion 22 , and limiting the friction between the piston 7 a , 7 b and the relative cylinder 2 a , 2 b .

[0024] The cylinders 2a, 2b and associated pistons 7a, 7b are configured and oriented such that:

[0025] Each piston 7a, 7b has a maximum width L1 measured parallel to the direction 5, which is smaller than a maximum width L2 measured parallel to a direction 24, which is parallel to the face 19 of the piston 7a, 7b and transverse to the direction 5; and

[0026] Each cylinder 2a, 2b has a maximum inner width L3 measured parallel to the direction 5 (maximum inner width L3 is rounded up to the width L1) and a maximum inner width L4 measured parallel to the direction 24 (maximum inner width L4 is rounded up to the width L2 and is greater than the width L3).

[0027] Each piston 7a, 7b also has a plurality of recesses 25, each recess being configured to accommodate a respective elastic band (known and not shown) designed to couple the piston 7a, 7b and the associated cylinder 2a, 2b to each other in a fluid-tight manner.

[0028] The drive engine 1 has several advantages which derive primarily from the fact that the cylinder groups 3, 4 of the cylinders 2a, 2b have a relatively limited footprint in direction 5 and the cavities 23 ensure relatively limited friction between the cylinders 2a, 2b and the associated pistons 7a, 7b.

Claims

1. A driving engine for a vehicle, comprising: a crankshaft (8) mounted for rotation about an axis of rotation (9); At least one first cylinder group (3), which in turn comprises at least two first cylinders (2a), which are aligned with each other in a first direction (5), which is parallel to the rotation axis (9) of the crankshaft (8); a first piston (7a), which is engaged in each first cylinder (2a) in a sliding manner and is defined by a free surface (19); and at least one first connecting rod (10), which is interposed between each first piston (7a) and the crankshaft (8); the free surface (19) of each first piston (7a) has a first width (L1) measured parallel to the first direction (5) and a second width (L2) measured parallel to a second direction (24), which is transverse to the first direction (5); and is characterized in that the first width (L1) of each first piston (7a) is smaller than the associated second width (L2).

2. The drive engine according to claim 1 further comprises a second cylinder group (4), the second cylinder group (4) further comprising a plurality of second cylinders (2b), the plurality of second cylinders (2b) being the same number as the first cylinder (2a), the plurality of second cylinders (2b) being aligned with each other in the first direction (5) and slidably engaged through corresponding second pistons (7b), the second pistons (7b) being connected to the crankshaft (8) by means of corresponding second connecting rods (13).

3. The drive engine according to claim 2, wherein: Each first connecting rod (10) is rotationally engaged by the crankshaft (8) and is directly coupled to a corresponding second connecting rod (13) in a rotationally coupled manner.

4. The drive engine according to claim 3, wherein: Each first connecting rod (10) is substantially coplanar with a corresponding second connecting rod (13).

5. The drive engine according to claim 3 or 4, wherein: Each second connecting rod (13) extends between two rotation axes (14, 15), one rotation axis being the rotation axis of the second connecting rod (13) relative to the first connecting rod (10) and the other rotation axis being the rotation axis of the second connecting rod (13) relative to the second piston (7b).

6. The drive engine according to any one of claims 2 to 5, wherein: Each second piston (7b) is delimited by a free surface (19) having the first width (L1) measured parallel to the first direction (5) and the second width (L2) measured parallel to the second direction (24).

7. A drive engine according to any one of the preceding claims, wherein: Each cylinder (2a, 2b) has a third width (L3) measured parallel to the first direction (5) and a fourth width (L4) measured parallel to the second direction (24), wherein the third width is rounded up to the first width (L1), and the fourth width is rounded up to the second width (L2) and is greater than the third width (L3).

8. A drive engine according to any one of the preceding claims, wherein: Each piston (7a, 7b) is delimited by a side wall (20) comprising two first portions (21) having a substantially semi-cylindrical shape opposite to one another and two second portions (22) having a substantially flat shape opposite to one another, each of the two second portions (22) extending between the two first portions (21).

9. The drive engine according to claim 8, wherein: The side wall (20) has two cavities (23) facing each other.

10. The drive engine according to claim 9, wherein: Each cavity (23) is obtained at least in the region of the associated second portion (22), in particular in the region of the associated second portion (22) and in the region of each first portion (21).

11. A drive engine according to any one of the preceding claims, wherein: Each cylinder (2a, 2b) is delimited by a side wall (16) comprising two first portions (17) opposite each other and having a substantially semi-cylindrical shape and two second portions (18) opposite each other and having a substantially flat shape, each of the two second portions (18) extending between the two first portions (17).

12. A drive engine according to any one of the preceding claims, wherein: Each piston (7a, 7b) has a plurality of recesses (25), each of which is configured to receive a corresponding elastic band designed to couple the piston (7a, 7b) and the associated cylinder (2a, 2b) to each other in a fluid-tight manner.

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