GB2538330A

GB2538330A - Tie rod assembly

Info

Publication number: GB2538330A
Application number: GB1512094.2A
Authority: GB
Inventors: Aspin Thomas
Original assignee: Tata Motors European Technical Centre PLC; Tata Motors Ltd
Current assignee: Tata Motors European Technical Centre PLC; Tata Motors Ltd
Priority date: 2015-05-14
Filing date: 2015-07-10
Publication date: 2016-11-16
Also published as: GB201512094D0

Abstract

The present disclosure relates to a tie rod assembly 1 comprising an elongated member 7 having a longitudinal axis X: a first connector 3: and a second connector 4. The first and second connectors 3, 4 are disposed at respective ends of the elongated member 7. The first connector 3 has a first connecting ring 5 having a first central axis Y. A first bush 9 is disposed in the first connecting ring 5. The first bush 9 includes a first bore 13 for receiving a retaining member 12. The first bore 13 has a first bore axis Y1 which is inclined at an acute angle A, to the first central axis Y. The present disclosure also relates to a vehicle 2 incorporating one or more tie rod assembly 1.

Description

TIE ROD ASSEMBLY

TECHNICAL FIELD

The present disclosure relates to a tie rod assembly. More particularly, but not exclusively, the present disclosure relates to an engine mounting tie rod. The present disclosure also relates to a vehicle incorporating one or more tie rod assembly.

BACKGROUND

A front wheel drive engine mounting structure typically consists of three mountings; first and second mass carriers which support the weight of the powertrain, and a third mounting which acts to restrain driveshaft torque reaction loads. The third mounting normally takes the form of a rigid link or tie rod having first and second connectors disposed at respective ends. The first connector comprises a parallel bonded resilient bush. The second connector comprises a variable stiffness bush. The variable stiffness bush has a larger diameter than the parallel bonded resilient bush. The tie rod assembly is attached to the powertrain at one end, and the vehicle body structure at the other. The bushes are usually fitted vertically or horizontally, and are attached to the vehicle body structure using fixings which are aligned to a central axis of the bush. The axis of each bush is perpendicular to the axis of the tie rod in order to prevent the bushes being subject to axial load.

The tie rod could be arranged substantially horizontally when installed in the vehicle. It has been recognised that, in order to improve the performance of the mounting system, the tie rod can be placed at an angle of between 8° and 10° to the horizontal. However, the existing vehicle structure may have fixing points which cannot readily be changed to adjust the orientation of the tie rod. A typical vehicle structure may require that the larger rear bush is attached to the body structure using a vertical bolt.

It is against this backdrop that the present invention has been conceived. At least in certain embodiments, the tie rod assembly described herein seeks to overcome or address at least some of the shortcomings associated with prior art arrangements.

SUMMARY OF THE INVENTION

Aspects of the present invention relate to a tie rod assembly; and to a vehicle Incorporating one or more tie rod assembly.

According to a further aspect of the present invention there is provided a tie rod assembly comprising: an elongated member having a longitudinal axis; a first connector disposed at a first end of the elongated member; a second connector disposed at a second end of the elongated member; the first connector comprising a first connecting ring having a first central axis; wherein a first bush is disposed in the first connecting ring, the first bush comprising a first bore for receiving a retaining member, the first bore having a first bore axis which is inclined at an acute angle to the first central axis. The tie rod assembly can be used with existing vehicle body structures, for example to accommodate different powertrains. The orientation of the elongated member can be altered without changing the vehicle body structure. For example, the elongated member can be inclined whilst connecting to horizontal or vertical fixings in the vehicle body structure.

The first central axis is coincident with the centre of the first connecting ring and extends perpendicular to a plane in which the first connecting ring is formed.

The first central axis of the first connecting ring and the longitudinal axis of the elongated member can define a reference plane. The first central axis can be perpendicular to the longitudinal axis. The first bore axis can be disposed within said reference plane.

The acute angle can, for example, be between 0° and 10°. In certain embodiments the acute angle can be between 8° and 10°.

The first bush can comprise a first guide surface and a second guide surface. The first guide surface and/or the second guide surface can be disposed substantially perpendicular to the first bore axis.

The first bush can comprise a resilient annular member and a first central insert. The first bore can be formed in said first central insert. The first central insert can define said first guide surface and/or said second guide surface. For example, the first guide surface can be formed at an upper end of the first central insert and the second guide surface can be formed at a lower end of the first central insert.

The first central insert can be symmetrical about the reference plane defined by the first central axis and the longitudinal axis. A central longitudinal axis of the first central insert can be arranged substantially coincident with said first central axis.

The first central insert can be cylindrical. The first central insert can have a transverse cross-section (in a plane perpendicular to the first central axis) which is circular or elliptical. The first central insert can comprise a cylindrical sidewall. In certain embodiments the first central insert can comprise an oblique cylindrical sidewall. The cylindrical sidewall can be arranged substantially concentrically with the first central axis. The sidewall of the first central insert and an inner surface of the first connecting ring can be arranged concentrically. This arrangement can help to reduce or prevent axial loading of the first bush.

The first central insert can have a transverse cross-section (in a plane perpendicular to the first central axis) which is polygonal. For example, the transverse cross-section of the first central insert can be triangular, rectangular, or square. The sidewall can, for example, comprise a plurality of substantially planar sections. The sections can be arranged substantially parallel to the first central axis.

The insert can be a rigid member. The insert can, for example, be formed from a metal or a metal alloy. The insert can be die-cast.

The resilient annular member can be formed from an elastomeric material. The resilient annular member can be a variable stiffness member.

The second connector can comprise a second connecting ring having a second central axis. The second central axis is coincident with the centre of the second connecting ring and extends perpendicular to a plane in which the second connecting ring is formed. The second central axis can be arranged perpendicular to the first central axis. The second central axis can extend perpendicular to the reference plane defined by the longitudinal axis of the elongate member and the first central axis.

The elongated member can be extended along its longitudinal axis. The first connecting ring can be mounted to a first end of the elongated member; and/or the second connecting ring can be mounted to a second end of the elongated member. The first connecting ring and/or the second connecting ring can be formed integrally with the elongated member.

The tie rod assembly can be an engine mounting tie rod. The tie rod assembly can be configured to restrain driveshaft torque reaction loads.

According to a further aspect of the present invention there is provided a vehicle comprising one or more tie rod assembly as described herein.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which: Figure 1 shows a sectional view a tie rod assembly coupled to a vehicle powertrain in accordance with an embodiment of the present invention; Figure 2 shows a plan view of the tie rod assembly shown in Figure 1; Figure 3 shows a side elevation view of the tie rod assembly shown in Figure 2; Figure 4 shows a sectional side elevation view of the tie rod assembly shown in Figure 1; Figure 5 shows a perspective view of the tie rod assembly shown in Figure 1; Figure 6 shows a perspective view of a vehicle powertrain in combination with the tie rod assembly shown in Figure 1; and Figure 7 shows a schematic representation of a vehicle incorporating the tie rod assembly in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

A tie rod assembly 1 in accordance with an embodiment of the present invention will now be described with reference to the accompanying figures. The tie rod assembly 1 in the present embodiment is an engine mounting tie rod for use in a vehicle 2 to restrain driveshaft torque reaction loads, as shown in section in Figure 1.

As shown in Figures 2 and 3, the tie rod assembly 1 comprises a first connector 3 and a second connector 4. The first connector 3 comprises a first connecting ring 5 (most clearly shown in Figure 2); and the second connector 4 comprises a second connecting ring 6 (most clearly shown in Figure 3). In the present embodiment, the first connecting ring 5 has a diameter of 92mm and the second connecting ring 6 has a diameter of 52mm. The first connecting ring 5 and the second connecting ring 6 are connected to each other by an elongated member 7 which extends along a longitudinal axis X of the tie rod assembly 1. In the present embodiment, the first and second connecting rings 5, 6 are formed integrally with the elongated member 7. The elongated member 7 and the first and second connecting rings 5, 6 are formed as a one-piece metal component, for example by die-cast moulding or machining. The elongated member 7 is configured to support operational loads (in compression or tension) applied along the longitudinal axis X. As shown in Figure 4, the first connecting ring 5 defines a first circular aperture 8 having a first central axis,{ arranged orthogonal to the longitudinal axis X of the tie rod assembly 1.

The first central axis Y is coincident with the centre of the first circular aperture 8 and extends perpendicular to the plane of the first circular aperture 8. The longitudinal axis X and the first central axis Y together define a reference plane XY (coincident with the plane of the sectional view shown in Figure 4). A first bush 9 having a diameter of 73mm is mounted in the first circular aperture 8. As shown in Figures 4 and 5, the first bush 9 comprises a first annular member 10 and a first central insert 11. The first annular member 10 is in the form of a resilient member which is moulded from an elastomeric material, such as rubber, and provides a variable stiffness support for the first central insert 11. The first annular member 10 is formed concentrically with the first connecting ring 5.

The first central insert 11 is in the form of a rigid member configured to support a first retaining member 12 in the form of a first bolt. The first central insert 11 is symmetrical about the reference plane XY. The first connecting ring 5 and the first central insert 11 are arranged coaxially such that a central longitudinal axis of the first central insert 11 is coincident with the first central axis Y. The first central insert 11 is made of metal or a metal alloy and can, for example, be die-cast. The first central insert 11 is fixedly connected to the first annular member 10 to inhibit relative rotational movement. The first central insert 11 can, for example, be bonded to the first annular member 10. A first bore 13 extends through the first central insert 11 to receive the first retaining member 12. The first bore 13 in the present embodiment has a diameter of 12.2mm. The first bore 13 has a first bore axis Y1 disposed within the reference plane XY and inclined at an angle a relative to the first central axis Y. It will be appreciated that the first bore axis Y1 is also inclined at said angle a relative to the central longitudinal axis of the first central insert 11. The angle a is an acute angle which in the present embodiment is 5.7° (±1°).

The first central insert 11 has an upper guide surface 14, a lower guide surface 15 and a sidewall 16. The upper and lower guide surfaces 14, 15 are arranged substantially perpendicular to the first bore axis Y1. The upper and lower guide surfaces 14, 15 are substantially planar and, as described herein, are arranged to cooperate with respective upper and lower locating members 17, 18. The first central insert 11 according to the present embodiment has a transverse cross-section (in a plane perpendicular to the central longitudinal axis) which is rectangular. As shown in Figure 2, the sidewall 16 comprises first, second, third and fourth planar sections 16A-D arranged perpendicular to each other. The first and third planar sections 16A, 16C are disposed parallel to the reference plane XY; and the second and fourth planar sections 16B, 16D are disposed perpendicular to the reference plane XY.

The second connecting ring 6 defines a second circular aperture 19 and has a second central axis Z arranged orthogonal to the reference plane XY defined by the longitudinal axis X and the first central axis Y. A second bush 20 having a diameter of 32mm is mounted in the second circular aperture 19. The second bush 20 comprises a second annular member 21 and a second central insert 22. The second annular member 21 is in the form of a resilient member which is moulded from an elastomeric material. The second central insert 22 is in the form of a rigid sleeve configured to support a second retaining member 23 in the form of a second bolt. In the present embodiment the second bush 20 is a parallel bonded bush. A second bore 24 is formed in the second central insert 22 to receive the second retaining member 23. The second bore 24 has a second bore axis Z1 arranged coincident with the second central axis Z. The second bore 24 in the present embodiment has a diameter of 12.2mm. In the present embodiment, the second bore 24 is non-circular and is elongated in a direction extending substantially coincident with the longitudinal axis X to allow for the take-up of build tolerances. The second bush 20 is adapted to provide directional stiffness properties. In particular, the second annular member 21 comprises first and second part-cylindrical apertures 25-1, 25-2. The first and second part-cylindrical apertures 25-1, 25-2 are diametrically opposed from each other along a diameter D of the second connecting ring 6. As shown in Figure 4, the diameter D is angularly offset from the longitudinal axis X within the reference plane XY by an acute angle which is substantially equal to the angle a. The diameter D and the first bore axis Y1 are substantially perpendicular to each other. The angular offset of the diameter D alters the directional stiffness properties of the second bush 20. A flat 26 is formed in an outer surface of the second connecting ring 6, as shown in Figures 3 and 4.

The first connector 3 is fabricated by moulding the first annular member 10 in the first connecting ring 5. This technique is substantially unchanged from prior art techniques. However, the mould used to form the first annular member 10 is modified to support the first central insert 11 in the appropriate orientation during moulding. The subsequent installation of the tie rod assembly 1 is unchanged from prior art arrangements.

The tie rod assembly 1 forms part of a mounting structure for mounting a powertrain 27 to a body structure 28 of the vehicle 2. A perspective view of the tie rod assembly 1 and the powertrain 27 are shown in Figure 6. The powertrain 27 comprises an internal combustion engine 29 which in the present embodiment is mounted transversely in the vehicle 2. The mounting structure comprises two mass carriers (not shown) which support the weight of the powertrain 27. The tie rod assembly 1 is configured to restrain driveshaft torque reaction loads. The first retaining member 12 is arranged substantially vertically and is connected to the body structure 28. The second retaining member 23 is arranged substantially horizontally and is connected to a sub-frame 30 of the powertrain 27. As shown in Figure 6, due to the geometry of the body structure 28, the tie rod assembly 1 cannot be arranged horizontally. Instead, the longitudinal axis X of the tie rod assembly 1 is inclined at an acute angle a relative to the horizontal (represented by a horizontal line H in Figure 1). Consequently, the first central axis Y of the first connecting ring 5 is inclined at said angle a relative to the vertical (represented by a vertical line V in Figure 1). The first central insert 11 is configured to accommodate the inclined arrangement of the tie rod assembly 1. The first connecting ring 5, the first annular member 10 and the sidewall 16 are arranged concentrically about the first central axis Y. However, the first bore axis Y1 is inclined at said angle a relative to the first central axis Y such that it is operatively arranged substantially vertically. The first central insert 11 thereby accommodates the angular offset of the tie rod assembly 1. The tie rod assembly 1 in accordance with the present invention is shown schematically in the vehicle 2 in Figure 7. The tie rod assembly 1 extends longitudinally within the vehicle 2 and is arranged substantially perpendicular to a crankshaft of the internal combustion engine 29.

The flat 26 is formed in the second connecting ring 6 to provide clearance between the tie rod assembly 1 and the sub-frame 30, as shown in Figure 1.

The upper and lower guide surfaces 14, 15 of the first central insert 11 are arranged substantially horizontally and cooperate with the upper and lower locating members 17, 18 in the body structure 28. In use, the first central insert 11 allows rotation of the tie rod assembly 1 about the first bore axis Y1. The resulting operational loads applied to the first retaining member 12 are within normal load levels. Moreover, the concentric arrangement of the first connecting ring 5 and the sidewall 16 of the first central insert 11 is effective to transfer operational loads through the first annular member 10 along the longitudinal axis X. It will be appreciated that various changes and modifications can be made to the tie rod assembly 1 described herein without departing from the scope of the present invention.

Claims

CLAIMS: A tie rod assembly (1) comprising: an elongated member (7) having a longitudinal axis (X); a first connector (3) disposed at a first end of the elongated member (7); a second connector (4) disposed at a second end of the elongated member (7); the first connector (3) comprising a first connecting ring (5) having a first central axis (Y); wherein a first bush (9) is disposed in the first connecting ring (5), the first bush (9) comprising a first bore (13) for receiving a retaining member (12), the first bore (13) having a first bore axis (Y1) which is inclined at an acute angle to the first central axis (Y).
2. A tie rod assembly (1) as claimed in claim 1, wherein the first bore axis (Y1) is disposed within a reference plane defined by the first central axis (Y) and the longitudinal axis (X).
3. A tie rod assembly (1) as claimed in claim 1 or claim 2, wherein the first central axis (Y) is perpendicular to the longitudinal axis (X).
4. A tie rod assembly (1) as claimed in any one of claims 1, 2 or 3, wherein said acute angle is between 0° and 10°.
5. A tie rod assembly (1) as claimed in any one of claims 1 to 4, wherein the first bush (9) comprises a first guide surface and a second guide surface, said first guide surface and/or said second guide surface being disposed substantially perpendicular to the first bore axis (Y1).
6. A tie rod assembly (1) as claimed in any one of the preceding claims. wherein the first bush (9) comprises a resilient annular member (10) and a first central insert (11), the first bore (13) being formed in said first central insert (11).
7. A tie rod assembly (1) as claimed in claim 6, wherein the first central insert (11) is symmetrical about a reference plane defined by the first central axis (Y) and the longitudinal axis (X).
8. A tie rod assembly (1) as claimed in claim 6 or claim 7, wherein the first central insert (11) has a central longitudinal axis arranged substantially coincident with said first central axis (Y).
9. A tie rod assembly (1) as claimed in any one of claims 6, 7 or 8, wherein said first central insert (11) is cylindrical.
10. A tie rod assembly (1) as claimed in claim 9, wherein the first central insert (11) comprises a cylindrical sidewall (16) which is substantially concentric with an inner surface of the first connecting ring (5).
11. A tie rod assembly (1) as claimed in any one of claims 6, 7 or 8, wherein the first central insert (11) has a transverse cross-section which is polygonal.
12. A tie rod assembly (1) as claimed in claim 11, wherein the transverse cross-section of the first central insert (11) is triangular, rectangular, or square.
13. A tie rod assembly (1) as claimed in any one of claims 6 to 12, wherein said first central insert (11) is a rigid member.
14. A tie rod assembly (1) as claimed in any one of claims 6 to 13, wherein the resilient annular member (10) is formed from an elastomeric material.
15. A tie rod assembly (1) as claimed in any one of the preceding claims, wherein the second connector (4) comprises a second connecting ring (6) having a second central axis (Z).
16. A tie rod assembly (1) as claimed in claim 15, wherein said second central axis (Z) is perpendicular to the first central axis (Y).
17. A tie rod assembly (1) as claimed in any one of the preceding claims, wherein said tie rod assembly (1) is an engine mounting tie rod.
18. A vehicle (2) comprising one or more tie rod assembly (1) as claimed in any one of the preceding claims.
19. A tie rod assembly (1) substantially as herein described with reference to the accompanying figures.
20. A vehicle substantially as herein described with reference to the accompanying figures.