WO2005080181A1

WO2005080181A1 - Cab tilt cylinder

Info

Publication number: WO2005080181A1
Application number: PCT/SE2005/000132
Authority: WO
Inventors: Tomas SKEPPSTRÖM
Original assignee: Scania CV AB
Current assignee: Scania CV AB
Priority date: 2004-02-18
Filing date: 2005-02-02
Publication date: 2005-09-01
Anticipated expiration: 2006-08-18
Also published as: DE112005000282T5; SE0400446D0; SE525103C2; SE0400446L; BRPI0506570A

Abstract

The invention relates to a cab tilt cylinder (2) for a vehicle cab (4) whereby the end (6) of the cylinder housing (8) of the cab tilt cylinder (2) from which the piston rod (10) of the cab tilt cylinder (2) protrudes is fastened pivotably to a relatively fixed portion (12) of the vehicle (14), with the result that the lever arm B of the cab tilt cylinder (2) relatively to the tilt point (20) of the vehicle cab (4) remains relatively constant throughout the tilting process.

Description

CAB TILT CYLINDER

Technical field

The present invention relates to a cab tilt cylinder for a vehicle cab, whereby the cylinder housing of the cab tilt cylinder is fastened pivotably to a relatively fixed portion of the vehicle.

Background

Heavy vehicles such as trucks often have a tiltable cab beneath which the vehicle's engine is situated. The cab can be tilted forwards about a tilt point to render the engine accessible for servicing.

US 3 642 316 A refers to a cab tilt cylinder for a vehicle whereby the cylinder housing of the cylinder is fastened to the vehicle's frame at the end of the cylinder opposite to the end where the cylinder's piston rod protrudes from the cylinder housing.

A problem with known tiltable cabs is that the cab tilt cylinder is subject to great stresses, particularly when the cab has to be lowered back down, since the distance between the cab's tilt point and the cylinder's piston rod is very short in the cab's lowered position.

Brief description of the invention

The problem of the cab tilt cylinder being subject to great stresses is solved according to the invention by arranging a cab tilt cylinder for a vehicle cab according to claim 1.

A cab tilt cylinder comprising the characteristics of claim 1 affords the advantage that the distance between the cab's tilt point and the cylinder's piston rod does not shorten considerably during the cab tilt movement. The stresses on the cab tilt cylinder are thus reduced by the fact that the lever between the cab's tilt point and the cylinder's fastening point in the chassis does not approach zero.

Brief list of the drawings

The invention is illustrated below in more detail with reference to the attached drawings, in which:

Figure 1 depicts schematically a forward portion of a vehicle, with the vehicle cab in its lowered position, and

Figure 2 depicts schematically a forward portion of a vehicle, with the vehicle cab in its raised position.

Description of preferred embodiments

The same reference notations are used throughout for the same features in the various drawings.

The present invention relates to a cab tilt cylinder 2 for a vehicle cab 4 whereby the end 6 of the cylinder housing 8 of the cab tilt cylinder 2 from which the piston rod 10 protrudes is fastened pivotably to a relatively fixed portion 12 of the vehicle 14.

Figure 1 depicts schematically a forward portion of a vehicle 14, with the vehicle cab 4 in the lowered position. A cab tilt cylinder 2 is arranged on at least one side of the vehicle 14 and fastened to a relatively fixed portion 12 of the vehicle 14, whereby the relatively fixed portion 12 may for example be a wheel suspension (not depicted) of the vehicle but is preferably the frame 16 of the vehicle 14. The cab tilt cylinder 2 is preferably arranged forward of the front wheels 18 of the vehicle 14. The cab tilt cylinder 2 comprises a cylinder housing 8 and a piston rod 10. The cylinder housing 8 of the cab tilt cylinder 2 is fastened pivotably, at its end 6 from which the piston rod 10 protrudes, to a relatively fixed portion 12 of the vehicle 14. The piston rod 10 is fastened to the cab 4 of the vehicle 14 at its end 19 which is arranged on the outside of the cylinder housing 8. The cab 4 of the vehicle 14 further exhibits a tilt point 20 about which the cab 4 of the vehicle 14 is pivotably fastened.

Figure 2 depicts schematically a forward portion of a vehicle 14, with the vehicle cab 4 in the raised position. The cab 4 is tilted so far about the tilt point 20 of the cab 4 that the centre of gravity 22 of the cab 14 is forward of the tilt point 20 of the cab 4, which means for example that the angle of opening between the cab's raised and lowered positions has to be of the order of 60 degrees for the cab 4 not to be able to fall back down by itself. For further safety, a stay 24 is used between the cab 4 and the frame 16 of the vehicle 14 to lock the cab 4 in its raised position. As may be seen in the drawing, the cab tilt cylinder 2 pivots about its fastening point 26 on the frame 16 of the vehicle 14, while the other end 28 of the cab tilt cylinder 2, which in the drawing is the lower end, effects a pivoting movement A towards the front wheels 18 of the vehicle 14. To enable the cylinder housing 8 to pivot freely, the steering gear (not depicted) of the vehicle 14 is arranged on the other side of the vehicle 14.

As the cab tilt cylinder 2 pivots about its end 6 from which the piston rod 10 protrudes, the lever arm B of the cab tilt cylinder 2 relative to the tilt point 20 of the cab 4 will remain relatively constant throughout the tilting process, whereby the forces between the cab tilt cylinder 2 and the cab 4 remain relatively constant. As the lever arm B does not shorten in the same way as in the case of the previously known tilt cylinder, the forces will be smaller, making it possible to use a cylinder with smaller dimensions.

Claims

1. A cab tilt cylinder for a vehicle cab, characterised in that the end (6) of the cylinder housing (8) of the cab tilt cylinder (2) from which the piston rod (10) of the cab tilt cylinder (2) protrudes is fastened pivotably to a relatively fixed portion (12) of the vehicle (14), with the result that the lever arm (B) of the cab tilt cylinder (2) relative to the tilt point (20) of the vehicle cab (4) remains relatively constant throughout the tilting process.

2. A cab tilt cylinder according to claim 1, characterised in that the relatively fixed portion (12) of the vehicle (14) is the frame (16) of the vehicle (14).

3. A cab tilt cylinder according to any one of the foregoing claims, characterised in that the cylinder housing (8) of the cab tilt cylinder (2) is fastened pivotably forward of the front wheels (18) of the vehicle (14).

4. A cab tilt cylinder according to any one of the foregoing claims, characterised in that the cab (4) in its raised position is tilted so far about the tilt point (20) of the cab (4) that the centre of gravity (22) of the cab (4) is forward of the tilt point (20) of the cab (4).