Internal combustion engine of a motor vehicle equipped with a fresh air intake throttle body

Abstract

Internal combustion engine of a motor vehicle comprising a cylinder head (2) containing at least one camshaft arranged along a main axis, a cylinder head cover (4) made by metal casting, having a gasket surface on the cylinder head (2) arranged along the main axis, and a housing (22) comprising a throttle valve for regulating the intake air flow into the engine, the cylinder head cover (4) comprising an extension made of the same casting material, forming an integrated support (10) having at its end an arm (16) having holes (20) for fixing the throttle valve housing (22) comprising an air outlet (24) the extension of which passes over the cylinder head cover (4). Figure 1

Description

Title of the invention: MOTOR VEHICLE HEAT ENGINE EQUIPPED WITH A FRESH AIR INTAKE BUTTERFLY VALVE HOUSING

[0001] The present invention relates to a motor vehicle heat engine equipped with a fresh air intake throttle body, and to a motor vehicle comprising this type of heat engine.

[0002] A known type of cylinder head cover for a thermal engine, presented in particular by document FR-A1-3026789, forms an elongated part along the main axis of rotation of the engine, produced by casting an aluminum alloy, comprising a lower joint plane fitting onto the top of the cylinder head which comprises at least one camshaft.

[0003] Camshafts comprising several guide bearings have axes adjusted at the level of the upper joint plane of the cylinder head receiving the cylinder head cover. Each bearing is formed half in the cylinder head and half in the cylinder head cover, screws arranged on each side of a bearing rigidly clamp these two half-bearings on each other. The cylinder head cover thus forms both the upper half of all the camshaft bearings, and a cover closing the interior volume of the cylinder head receiving the engine lubricating fluid.

[0004] The top of the cylinder head cover further has a longitudinal duct having at one end an intake air inlet, which distributes this air to each intake valve arranged in the cylinder head to integrate the air inlet of the thermal engine into this cylinder head cover.

[0005] Furthermore, certain thermal engines comprise a housing made from a plastic molding containing a butterfly valve for adjusting the flow of fresh air into the engine, as well as the control elements of this butterfly valve, this housing forming a subassembly fixed to the engine.

[0006] In particular, it is known to produce a support formed by an aluminum alloy casting, fixed on one side to the cylinder head cover, and on the other side having a plane having holes receiving a bearing face of the throttle body. The throttle body is generally arranged in the upper part of the thermal engine having an outlet which extends along the same axis by a conduit passing above the cylinder head cover, to supply in the most direct manner the intake conduits of the thermal engine located in the cylinder head.

[0007] However, with a certain length of the support to establish a distance between the throttle body and the cylinder head in order to position this housing above the engine thermal, we obtain a cantilevered mounting of the housing at the end of the support which is screwed onto the cylinder head cover, which can lead to rigidity problems causing vibrations, and reliability problems with risks of loosening.

[0008] In addition, this fixing of the throttle body to the end of the support requires a rigid intermediate support, made of a metallic material, which results in manufacturing and management costs for the supply of this additional part and its clamping elements. This fixing also requires assembly time on the thermal engine with the various screws, including handling of the subassembly formed by the housing and its support, which can be not very ergonomic due to the size and weight of this subassembly.

[0009] The present invention aims in particular to avoid these problems of the prior art.

[0010] To this end, it proposes a thermal engine for a motor vehicle comprising a cylinder head containing at least one camshaft arranged along a main axis, a cylinder head cover made from a metal casting, having a joint plane on the cylinder head passing through the main axis, and a housing comprising a throttle valve for adjusting the intake air flow into the engine, this heat engine being remarkable in that the cylinder head cover comprises an extension made from the same casting material, forming an integrated support having at its end an arm having holes for fixing the throttle housing comprising an air outlet whose extension passes above the cylinder head cover.

[0011] An advantage of this heat engine is that by the same molding we form in the cylinder head cover a support for the throttle body which allows to obtain without intermediate part a robust, not very flexible and reliable fixing of this housing arranged at a distance from the cylinder head, allowing to obtain an outlet duct passing directly above the cylinder head cover. For assembly on the thermal engine the throttle body alone then constitutes a compact and light subassembly allowing ergonomic handling for its installation on this engine.

[0012] The heat engine according to the invention may further comprise one or more of the following characteristics, which may be combined with each other.

[0013] Advantageously, the integrated support comprises successively, starting from the cylinder head cover, a vertical boss which rises above the upper level of this cylinder head cover, then a substantially horizontal plate which moves away towards one side of the thermal engine.

[0014] In this case, advantageously the arm forms, starting from the end of the horizontal plate, a plane which is turned upwards.

[0015] In addition, the plane of the arm can be arranged substantially vertically.

[0016] In particular, the plane of the arm may be substantially parallel to the main axis.

[0017] Advantageously, the horizontal plate has a downward extension forming an equipment fixing device.

[0018] In this case, advantageously the integrated support comprises ribs which connect the horizontal plate to the downward extension.

[0019] Advantageously, the downward extension ends with a horizontal edge having holes for fixing equipment.

[0020] Advantageously, the arm forms an arc of a circle having at each end a hole for fixing the throttle housing.

[0021] The invention also relates to a motor vehicle equipped with a thermal traction engine comprising any one of the preceding characteristics, remarkable in that the throttle body is arranged both next to and above the thermal engine.

[0022] The invention will be better understood and other characteristics and advantages will appear more clearly on reading the description below given by way of example, with reference to the appended drawings in which:

[0023] [Fig-1] is a view of a cylinder head of a heat engine according to the invention equipped with the cylinder head cover supporting the throttle body;

[0024] [Fig.2] is a side view of this cylinder head with its cylinder head cover;

[0025] [Fig.3] is a front view of this cylinder head with its cylinder head cover; and

[0026] [Fig.4] is a perspective view of this cylinder head with its cylinder head cover.

[0027] Throughout the document the upper or top side relates to a heat engine arranged vertically, as shown in the figures. In the vehicle the heat engine may have any different inclination.

[0028] Figures 1, 2, 3 and 4 show a cylinder head 2 of a four-cylinder thermal engine forming a flat assembly elongated along the main axis of rotation of the engine, receiving above a cylinder head cover 4 containing two camshafts each held by a series of bearings 6, each bearing being formed by two half-parts assembled along the joint plane between the cylinder head cover and the cylinder head.

[0029] The cylinder head cover 4 is associated with the cylinder head 2, both made by an aluminum alloy foundry, to constitute a highly rigid assembly which resists the high mechanical stresses coming from the pressure in the cylinders, and from the operation of the camshafts activating the valves arranged in the cylinder head.

[0030] A front end of the cylinder head 2 and cylinder head cover 4 assembly has holes 8 allowing the ends of the camshafts to pass through to drive them in rotation.

[0031] The cylinder head cover 4 comprises at its front end, on the side of the cylinder head 2, an integrated support 10 from the same foundry which protrudes from its overall volume towards the side of the engine and upwards, successively comprising, starting from the cylinder head cover, a vertical boss 12 which rises above the upper level of the cover cylinder head, a horizontal plate 14 which moves away towards the side of the thermal engine, then a vertical rising arm 16 arranged laterally outside the cylinder head.

[0032] The vertical arm 16 arranged in a plane parallel to the main axis, forms an arc of a circle comprising a hollow 18 substantially following a semicircle, which is framed at its ends by two holes 20 arranged along a diameter of this semicircle.

[0033] A throttle body 22 made by a plastic molding, has a circular intake air outlet 24 fitted in the hollow 18 of the integrated support 10. Two screws engaged in the holes 20 of the vertical arm 16, fix the throttle body 22 on the integrated support 10.

[0034] The integrated support 10 further comprises, from the end of the horizontal plate 14, an extension 26 which goes downwards then outwards to end with a horizontal edge 28 comprising two holes 30. Parallel ribs 32 arranged below the horizontal plate 14 connect this plate to the downwardly extending extension 26, providing strong stiffening of this plate, and of the vertical arm 16 supporting the mass of the throttle body 22.

[0035] The horizontal edge 28 supports below an air circuit connection, not shown, which is fixed by screws engaged in the holes 30.

[0036] By a simple modification of the casting shape of the cylinder head cover 4, an integrated support 10 is obtained, strongly connected to the cylinder head 2 and to the thermal engine, stiffened by ribs 32, which receives the throttle body 22 located at the end of this support, with a significant offset relative to the cylinder head 2 to position it above this cylinder head cover. This limits the vibrations of the throttle body 22 and its support subjected to the movements of the thermal engine, which avoids risks of loosening and failure.

[0037] On the assembly line of thermal engines, an operator positions and screws the throttle body 22 alone, forming a lightweight subassembly, which constitutes an ergonomic and quick operation to carry out with only two screws to be put in place for its fixing. This avoids an additional operation of positioning and screwing a support onto the cylinder head 2, requiring additional screws and adding costs.

Claims

Claims

1. Motor vehicle thermal engine comprising a cylinder head (2) containing at least one camshaft arranged along a main axis, a cylinder head cover (4) made by a metal casting, having a joint plane on the cylinder head (2) arranged along the main axis, and a housing (22) comprising a butterfly valve for adjusting the intake air flow into the engine, characterized in that the cylinder head cover (4) comprises an extension made from the same casting material, forming an integrated support (10) having at its end an arm (16) having holes (20) for fixing the butterfly housing (22) comprising an air outlet (24) the extension of which passes above the cylinder head cover (4).

2. Thermal engine according to claim 1, characterized in that the integrated support (10) successively comprises, starting from the cylinder head cover (4), a vertical boss (12) which rises above the upper level of this cylinder head cover (4), then a substantially horizontal plate (14) which moves away towards one side of the thermal engine.

3. Heat engine according to claim 2, characterized in that the arm (16) forms, starting from the end of the horizontal plate (14), a plane which is turned upwards.

4. Heat engine according to claim 3, characterized in that the plane of the arm (16) is arranged substantially vertically.

5. Heat engine according to claim 4, characterized in that the plane of the arm (16) is substantially parallel to the main axis.

6. Thermal engine according to any one of claims 2 to 5, characterized in that the horizontal plate (14) comprises a downward extension (26) forming a device for fixing equipment.

7. Heat engine according to claim 6, characterized in that the integrated support (10) comprises ribs (32) which connect the horizontal plate (14) to the downward extension (26).

8. Heat engine according to claim 6 or 7, characterized in that the downward extension (26) ends with a horizontal edge (28) having holes (30) for fixing equipment.

9. Thermal engine according to any one of the preceding claims, characterized in that the arm (16) forms an arc of a circle having at each end a hole (20) for fixing the throttle housing (22).

10. Motor vehicle equipped with a thermal traction engine according to any one of the preceding claims, characterized in that the throttle body (22) is arranged both next to and above the thermal engine.

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