RU2259286C1 - Vehicle seat suspension - Google Patents

Abstract

FIELD: transport engineering.

SUBSTANCE: invention is designed for use in vehicle of transportation and technological applications, particularly, in excavators, loaders, track vehicles, agricultural machines and some mining machines. Proposed vehicle seat suspension contains seat skeleton, base, levers, torsion bar and torsion bar rigidity adjuster. Seat skeleton and base are hinge-connected by levers, one arm of said levers being connected with torsion bar. Torsion bar is provided with flexible members in form of lengths of wire rope, with cams and end disks. Fixed axle of torsion bar is secured in support posts of base. Cams and end disks are made for free displacement along and relative to fixed axle of torsion bar, being spring-loaded relative to support port. Levers are connected with torsion bar through flexible tie secured by one end on axle of skeleton, and by other end, on cam of torsion bar and made to support seat skeleton through supporting roller. Torsion bar rigidity adjuster contains non-supporting disks are mechanism to displace said disks along fixed axle of torsion bar, flexible members made in form of concentric threaded bushings of "tube-in-tube" type. Cams are provided with fixing members by means of which they are connected with end disks provided with mating holes for fixing members. Flexible tie is connected with torsion bar through profiled surfaces of cams which are connected with end disks of torsion bar through spring-loaded fixing members. Load-relief spring is provided which is connected by one end with profiled surface of cam, and by other end, with base.

EFFECT: enlarged range of low-frequency vibration protection, improved operation reliability of seat suspension, provision of operating comfort for driver.

5 cl, 3 dwg

Description

Technical field

The invention relates to the equipment of vehicles and is intended for use in vehicles for transport and technological purposes, in particular in excavators, loaders, track machines, agricultural machines and some types of mining machines.

State of the art

Known vehicle seat suspensions in which attempts have been made to solve the problem of damping the low-frequency component. As is known, the damping of low-frequency vibration requires the use of suspensions with a low frequency of free vibrations and, therefore, with low stiffness. However, a decrease in stiffness leads to an increase in the skew of the supporting surface relative to the base under a possible eccentric load (the operator changes his posture during operation), which reduces the stability of the suspension. Therefore, the solution to the issue of protection against low-frequency vibration consists in the comprehensive resolution of two interrelated problems: ensuring the necessary effectiveness of vibration isolation and sufficient stability of the suspension under eccentric loading.

Known devices [1], where the reduction in transport under arbitrary loading is achieved by reducing the degrees of freedom of the elastic suspension due to various guiding devices. The most widespread of them are guides providing one degree of freedom, depicted in figure 1.

The simplest suspension with a guide, such as an axle-hub, used in the construction of loading and drilling machines, figure 1 (a) does not exclude distortions that exceed permissible.

Only damping of vertical vibration is possible, while mutual transformation of vertical and angular vibrations is characteristic [1].

Pendants with guides of the rod-sleeve type of FIG. 1 (b, c) allow damping vibration in only one direction. They have the simplest design when sliding friction between the rod and the sleeve, which reduces the effectiveness of vibration isolation [1]. The use of a rolling friction friction pair-sleeve pair leads to a significant complication of the guide and an increase in the wear of friction pairs [1].

Also known are devices with mechanisms of the type of parallelogram of FIG. 1 (g, d) [1, 6] and scissors [1, 7] of FIG. 1 (e, g). For parallelogram systems characterized by the mutual transformation of vertical and horizontal vibrations [1]. In their manufacture, high accuracy or the use of compensators is required.

Scissor systems are mainly used in suspensions with base plates of small dimensions. With this scheme, there is no transformation of vertical and horizontal vibrations and there are no problems of ensuring stability. Such a layout scheme is used as the base for a series of seats by firms such as KamAZ [2], Grammer [3].

For lever-roller systems of Fig. 1 (s, m), which are simpler in design, a change in the angle of inclination of the supporting surfaces during their vertical movement is characteristic, which is a disadvantage.

Suspensions are also known [4, 5], in which there are no rigid guides, for example, a two-stage rod cable vibration isolator of Fig. 1 (k, l). Such structures are able to reduce vibration and shock loads, the resulting vector of which is arbitrarily located in space. Their disadvantages are the difficulty of ensuring longitudinal and lateral stability, a significant complication of the design.

Known designs of vibration isolators in the form of torsion bars, which are performed mainly metal. Such torsion bars are used to attenuate both low and high frequencies. Their disadvantage is the low damping coefficient. From this point of view, rope vibration isolators have the best characteristics [7-10], where a steel rope is used as the material of their elastic elements. The elastic elements represent a system of short rods made of segments of a steel rope with fixed or freely sliding ends placed in the supporting elements. The working parts of the rope segments have the required bearing capacity and large damping.

Closest to the invention is a technical solution [11], comprising a suspension with a torsion bar, a torsion bar stiffness control mechanism and a torsion bar angle control mechanism associated with the seat frame and with two pairs of levers. This invention solves the problem of expanding the range of regulation. Its disadvantage is the low efficiency of damping oscillations in the low-frequency region due to the linearity of the implemented elastic characteristics, the design complexity of the damping device.

SUMMARY OF THE INVENTION

The basis of the invention is the task of increasing the efficiency of damping oscillations in the low-frequency region, creating a vehicle seat suspension having an expanded region of low-frequency vibration protection, a simpler design with greater operational reliability.

The solution to this problem is achieved by the fact that in the vehicle seat suspension containing the seat frame, base, levers, torsion bar and torsion stiffness control mechanism, the seat frame and base are pivotally connected using levers, one shoulder of which is connected to the torsion bar, according to the invention, the torsion bar is made with elastic elements in the form of segments of a rope, equipped with cams and end disks, the fixed axis of the torsion bar is fixed in the support struts of the base, cams and end disks are made with the possibility of In order to freely move along and relative to the fixed axis of the torsion bar and are spring-loaded relative to the support strut, the connection of the levers with the torsion bar is made in the form of a flexible rod fixed at one end on the axis of the carcass, and the second on the cam of the torsion bar, and made with the possibility of supporting the carcass of the seat through the supporting roller .

It is also envisaged that the torsion stiffness adjustment mechanism comprises non-support disks and a mechanism for moving them along the fixed axis of the torsion and elastic elements, made in the form of concentric threaded bushings of the "pipe in pipe" type; cams are provided with locking elements, by means of which they are connected to end disks made with mating holes for locking elements; a flexible rod is connected to the torsion bar through the profiled surfaces of the cams, and the latter are connected via spring-loaded fixing elements to the end disks of the torsion bar; introduced an unloading spring connected at one end to the profiled surface of the cam, and the other to the base.

The introduction of the above distinguishing features in the invention expands the field of low-frequency vibration protection due to the implementation of a substantially nonlinear elastic damping characteristic due to the use of the cable torsion bar and stiffness corrector in the form of a profiled cam in the proposed design. Moreover, the design of the proposed suspension is simplified, its operational reliability is increased. Thanks to the expansion of the low-frequency vibration protection area, comfortable conditions have been created for the vehicle operator.

Brief Description of the Drawings

The invention is illustrated by drawings, presented in figures 1-3. Figure 1 represents the known types of vehicle seat suspensions. Fig.2-3 represents the described device, Fig.2 is a General view, Fig.3 is a low-frequency torsion, view B of Fig.2.

Positions in figure 2, 3 are indicated:

1 - levers

2 - seat frame

3 - base

4 - elastic element

5 - cam

6 - support stand

7 - fixed axis of the torsion bar

8 - thrust flexible

9 - axis of the frame

10 - supporting roller

11 - unloading spring

12 - unsupported torsion discs

13 - mechanism for moving non-supporting disks

14 - locking elements

15 - trailer end drive,

16 - fixed end disk

17 - spring

18 - seat cushion

The best option for implementation

The vehicle seat suspension contains two pairs of guide levers 1 mounted on the sides of the seat pivotally connected to each other and with the seat frame 2 and base 3. Each pair of levers 1 with their lower shoulders is installed in the grooves of the base 3, and the upper in the grooves of the seat. The upper shoulder of each of the levers 1 is connected by an elastic rod 8 with a torsion bar. On the support rack 6 of the base 3 is fixed to the fixed axis 7 of the torsion bar. The torsion bar contains elastic elements 4 in the form of ropes fixed in the end disks 15, 16, and cams 5 with profiled surfaces and provided with locking elements 14. Two flexible rods 8 located symmetrically on both sides of the seat connect the inertial mass of the seat frame 2 with the seat cushion 18 with cam 5 torsion bars. Each flexible rod 8 is fixed at one end on the axis of the frame 9, and the second on the profiled surface of the cam 5 of the torsion bar. A frame is supported on each of the rods through supporting rollers 10 located symmetrically on both sides of the seat. The torsion bar is equipped with non-support disks 12 and a mechanism for their movement 13 along the fixed axis 7 and the elastic elements 4 of the torsion bar, designed to control the stiffness of the torsion bar.

The torsion bar cam 5 is provided with locking elements 14, and the movable disk 15 is provided with holes 19 for these locking elements, so that the cam 5 is connected to the disk 15 supported by the springs 17, this connection can be varied by turning the cam 5 relative to the end disk 15 and the contact of the locking elements 14 with corresponding holes 19 in the end disk. The cam 5 is also connected to the base 3 by means of a discharge spring 11.

Device operation

The device operates as follows. The stiffness of the suspension of the vehicle is regulated by moving the required amount, according to the weight of the operator, of the support disk 12 along the fixed axis 7 and the elastic elements 4 of the torsion bar.

When the vehicle is moving, the torsional moment is transmitted to the vibration isolator by means of a flexible rod 8 connected to the cam 5.

The presence of a cam allows you to create a variable twisting moment, the value of which is determined by the angle of inclination of the axis of symmetry of the cam to the horizontal. The task of obtaining a power characteristic with a section of reduced stiffness, providing an extension of the low-frequency protection region, is solved by applying a profiled disk and reduces to the task of creating a disk of variable radius, i.e. profiled cam torsion bar.

The angle of rotation of the cam relative to the end disk is selected in such a way that in the position of static equilibrium a flexible thrust through the cam creates the maximum torsion torque on the torsion bar, thereby ensuring minimum rigidity and, therefore, minimum natural vibration frequency, which ensures effective low-frequency vibration protection.

By changing the value of the angle of rotation of the cam relative to the end disk, a number of elastic characteristics can be obtained for different values of the mass of the operator, while their change is controlled by the angle of rotation of the cam 5, the displacement of the non-support disks 12 and the tension force of the unloading spring 11.

Thus, the introduction of distinctive features in the present invention allows to solve the problem - to expand the field of low-frequency vibration protection, increase the operational reliability of the seat suspension and create comfortable conditions for the driver.

Industrial applicability

The present invention is developed at the level of working drawings. Made a prototype. Positive results were obtained when operating a vehicle with the technical solution proposed in the invention.

Sources of information

1. Protection against noise and vibration in coal enterprises: a reference guide. Under the general ed. Yu.V. Flavitsky Yu.V. - M .: Nedra, 1990, - 368 p.

2. Golovin G.S. Ergonomics of mining equipment. - M. Nedra, 1990, - 183 p.

3. W. Diebschlag, H. Duis, E. Hartung. Seat ergonomics. Aspects of industrial medicine and technology relating to seat design. 1997 .-- 67 p.

4. Gorbunov V.F., Reznikov I.G. Cable vibration isolators to protect mining machine operators. - Novosibirsk: Science, 1988.

5. RF patent No. 2137626 published 09/20/99, Bull. No. 26.

6. Copyright certificate No. 371099, 1973.

7. Elastic safety clutch. Copyright certificate No. 1323782, F 16 D 7/04 43/20, 1998

8. Reduction of vibration and noise of pneumatic hand punchers. / Zhivotovsky A.A., Begagoen V.I., Gromadsky A.S., Artamonov G.V. et al. - Izv. universities. Mountain Journal. 1975, No. 8, p. 77-79. A.S., Artamonov G.V. et al. - Izv. universities. Mountain Journal. 1975, No. 8, p. 77-79.

9. Vibroprotective carriage of cable type (VZKT-2 m). / Gorbunov V.F., Reznikov I.G., Kozlov V.V., Narshakov A.S. et al .: Inform. Sheet No. 147-15. - Sverdlovsk, MTTSNTIiP, 1975.

10. Calculation of cable torsion bars. / Kozlov V.V., Reznikov I.G. Izv. universities. Mining Journal, 1981, No. 9, pp. 80-82.

11. Suspension of a vehicle seat. Copyright certificate No. 1472307, 60 N 1/02, 1989, prototype.

Claims (5)

1. A vehicle seat suspension comprising a seat frame, a base, levers, a torsion bar and a torsion stiffness control mechanism, the seat frame and base being pivotally connected by levers, one shoulder of which is connected to a torsion bar, characterized in that the torsion bar is made with elastic elements in the form of segments of the rope, equipped with cams and end disks, the fixed axis of the torsion bar is fixed in the support stands of the base, cams and end disks are made with the possibility of free movement along and relative to the torsion axle is fixed and spring-loaded relative to the support strut, the connection of the levers with the torsion bar is made in the form of a flexible rod fixed at one end to the axle of the carcass, and the second on the cam of the torsion bar and made with the possibility of supporting the seat carcass through the support roller. 2. The vehicle seat suspension according to claim 1, characterized in that the torsion stiffness adjustment mechanism comprises non-support disks and a mechanism for moving them along the fixed axis of the torsion and elastic elements, made in the form of concentric threaded bushings of the type pipe in a pipe. 3. The vehicle seat suspension according to claim 1, characterized in that the cams are provided with locking elements, by means of which they are connected to end disks made with mating holes for the locking elements. 4. The vehicle seat suspension according to claim 1, characterized in that the flexible rod is connected to the torsion bar through the profiled surfaces of the cams, and the latter are connected via spring-loaded locking elements to the end disks of the torsion bar. 5. The vehicle seat suspension according to claim 1, characterized in that an unloading spring is introduced, connected at one end to a profiled cam surface, and to the base with the other.

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