EP0528890A1

EP0528890A1 - A soil compacting vibrator

Info

Publication number: EP0528890A1
Application number: EP19910909187
Authority: EP
Inventors: Lars Andréasson
Original assignee: ESS VERK AB
Current assignee: ESS VERK AB
Priority date: 1990-05-02
Filing date: 1991-04-18
Publication date: 1993-03-03
Also published as: WO1991017322A1; SE9001573L; SE9001573D0; CA2081783A1; SE466164B

Abstract

Vibreur de tassement du sol présentant une partie supérieure (1), une partie inférieure (13) ainsi qu'une unité vibratoire (8) actionnée par un moteur hydraulique ainsi que des atténuateurs de vibrations (10) situés entre la partie supérieure (1) du vibreur et sa partie inférieure (13). Les atténuateurs de vibrations (10) sont montés en diagonale par rapport à la plaque inférieure (11) du vibreur de tassement du sol et, à chaque extrémité de la plaque inférieure (11), ils sont connectés d'une part à des plaques terminales (2) fixées à la partie supérieure (1) du vibreur et d'autre part à des plaques terminales (9) fixées à la partie inférieure (13) du vibreur. Les plaques terminales (2) et les plaques terminales (9) sont fixées de manière qu'elles sont parallèles mutuellement et en forme de V, leurs pointes étant tournées soit à l'extérieur du vibreur soit à l'intérieur de celui-ci. Du fait de cet agencement les plaques terminales (9) fonctionnent efficacement comme supports de maintien contre des masses de terre dans le nivellement avant le tassement.Soil compaction vibrator having an upper part (1), a lower part (13) and a vibrating unit (8) actuated by a hydraulic motor as well as vibration attenuators (10) located between the upper part (1) vibrator and its lower part (13). The vibration attenuators (10) are mounted diagonally to the lower plate (11) of the soil compacting vibrator and, at each end of the lower plate (11), they are connected on the one hand to end plates (2) fixed to the upper part (1) of the vibrator and on the other hand to end plates (9) fixed to the lower part (13) of the vibrator. The end plates (2) and the end plates (9) are fixed so that they are mutually parallel and V-shaped, their tips being turned either outside the vibrator or inside it. Due to this arrangement the end plates (9) function effectively as holding supports against earth masses in the leveling before the compaction.

Description

A SOIL COMPACTING VIBRATOR The present invention concerns a soil compacting vibrator for hydraulic operation mounted for example on a digging machine. Soil compacting vibrators are known and can be utilized mounted for example on digging machines or other machines. The vibrators of the prior art are designed so as to comprise a vibrating device for example consisting of one or more eccentrics, and they arc intended to be carried by the digging machine or for example by a crane in the case that they are to be lowered into a pit.

The vibrators may be hydraulically operated or operated by diesel or petrol. However, diesel or petrol operated vibrators have disadvantages which begin already in the plane of the ground and which thereafter increase with that dept under the plane of the ground at which operation is carried out, namely on the one hand that these machines, which generally are manually operated and self-propelled, deliver exhaust which fills the pit in which they operate, which comprises a health hazard to the operator, and on the other hand that the machines are heavy and therefore have to be lowered into the pit or at least be lifted up by a crane or alternatively by a digging machine.

An example of a soil compacting vibrator of conventional type is illustrated in Canadian Patent Specification No. 1 005 663, in which a frame which is intended to be suspended by the arm of a digging machine comprises an eccentric which is adapted to be operated by the hydraulic system of the digging machine, in addition to which the frame is interconnected to a soil compacting vibration plate via four elastomeric vibration attenuators which are located one at each corner of the frame. These attenuators interconnect the frame with the soil compacting vibratory plate and are mounted with their axes of symmetry in the transverse direction of the digging machine. The weakest direction of loading of the attenuators then becomes the same direction as that in which the forces of the digging machine become the greatest, i.e. the longitudinal direction of the digging machine, which is very unfavourable. Generally speaking, the attenuators have to be mounted in a specific relationship to the vibratory unit which has been selected. In the Canadian case the vibratory unit does not have a directional centrifugal force, i.e. the vibratory unit has equal centrifugal force around the whole revolution of the eccentric leftwards or rightwards. It would be more favourable if the centrifugal force were to be greater in a specific direction (the direction of operation) and smaller in another (exactly the opposite). The present invention has the object.of obviating the disadvantages mentioned above by disclosing a soil compacting vibrator of hitherto unknown type.

The relevant soil compacting vibrator can be designated as a "diagonal assembly with a V-shaped profile". The vibrator has a lower portion in the form of a bottom plate which when vibrating is to engage the ground or the material which is to be vibrated, respectively. The bottom plate has two V-positioned ends, and the upper portion of the vibrator has two

V-positioned end legs which are intended to cooperate with the ends of the bottom plate via vibration attenuators which for example may consist of rubber. The tips of the V-positioned ends can either face towards each other or away from each other. If the V-positioned ends have their end tips facing each other, i.e. have their convex parts facing the centre, a number of favourable and advantageous characteristics are achieved, particularly from the viewpoint that the soil compacting vibrator will have to stand up against the heavy stresses which are inevitable if it is to be utilized as an effective grading and levelling implement. Furthermore, the vibrator includes the mentioned vibration attenuators which are mounted diagonally with respect to the bottom plate of the vibrator.

In summary, the soil compacting vibrator according to the invention comprises an upper portion having a mount for a supporting arm, for example in a digging machine, wherein said arm, when being lifted, for example can extend in the longitudinal direction of said upper portion and the vibrator, and a lower portion comprising a bottom plate and the vibratory unit driven by a hydraulic motor, with vibration attenuators, for example of rubber, being disposed between the upper portion of the vibrator and its lower portion. The soil compacting vibrator is characterized by said vibration attenuators being mounted essentially diagonally with regard to the bottom plate of the soil compacting vibrator, that the vibration attenuators are at each end of the bottom plate connected on the one hand to end legs which are mounted to the upper portion of the vibrator and on the other hand to end plates which are mounted to the lower portion of the vibrator, and that the end legs and the end plates are secured in such manner that they have mutually parallel V-shape, with a tip either towards the outside of the vibrator or towards its inside. The vibratory unit can to advantage have twin eccentric wheels and directional centrifugal force. Furthermore, the vibratory unit can be positioned diagonally on the vibrator and can comprise one or more motors having hydraulic couplings and hoses as well as an interconnecting unit protected by said upper portion and end plates. The bottom side of the upper portion can be configured as an engagement surface for engaging the end plates so as to stop the motion of the upper portion of the vibrator towards the lower portion so as to avoid too great a load on the vibration attenuators.

The invention is defined in the accompanying claims, and it will be described more specifically below with reference to the accompanying drawings, in which Figure 1 illustrates a plan view of an example of a soil compacting vibrator in accordance with the invention including the ends of the bottom plate and the end legs of the upper portion mounted in V-shape with the tips of the relevant V*s facing each other, Figure 2 is an elevational view of the vibrator in accordance with Figure 1 , Figure 3 is an end view of the vibrator in accordance with Figure 1 , and Figure 4 is a plan view of the vibrator in accordance with the invention with the ends of the bottom plate and the end legs of the upper portion mounted in V-shape and with the tips of the relevant V^»s turned 180° as compared to the embodiment of Figures 1 - 3, respectively. The same designations have been utilized in the various figures wherever this has been possible. In the figures the designations refer to the following:

1 is the upper portion of the soil compacting vibrator, 1B is an arbitrary type and model of implement mount which is connected to a plate 1C in the upper portion and which is adapted to the type of machine which is to be used as a carrier, 2 are the end legs of the upper portion which are positioned in V-shape, 3 are side plates which reinforce the end legs of the upper portion and which furthermore are intended to function as mounting points if for example a traction device is disposed for performing compacting while being pulled by an appropriate traction vehicle, for example a wheel loader, 4 is an aperture in the upper portion 1 through which hydraulic hoses from the motor of the soil compacting vibrator are conducted to the top side of the upper portion and to a valve unit which is mounted there and is designated 5, the designation 6 refers to an internal pair of hoses, 7 is a hydraulic motor which is located in the lower portion 13 of the vibrator, the designation 8 refers to a vibratory unit with directed action, for example twin eccentric wheels which are disposed such as to provide a directional centrifugal force, 9 are end plates positioned in V-shape on a bottom plate 11 with sloping outer edges, 10 are vibration attenuators positioned diagonally with regard to the bottom plate 11 , the designation 12 refers to a clearance whose lower part restricts the load on the vibration attenuators by plate 1 being urged downwards towards the upper edges of the end plates 9 of the bottom plate 11 , said upper edges comprising an engagement member downwards, and 14 is a section of the outer portion of the end plates which is to function as fastening points for i.a. widening plates.

As may be seen for example in Figure 1 there are four vibration attenuators in the illustrated embodiment, but additional vibration attenuators can exist, for example by doubling the present four vibration attenuators. In Figure 1 the vibration attenuators are mounted on the insides of the bottom ends 9, but there is nothing to prevent mounting them on the outsides, i.e. the concave side in the relevant case or, if desired, both on the outsides and the insides.

In consequence of the substantially diagonal assembly all of the forces in the horizontal direction which occur as soon as grading and levelling movements are to be provided will be taken up progressively by the vibration attenuators 10 without any mechanical engagement members being necessary for relieving the vibration attenuators in the mentioned direction.

What actually occurs is that regardless of from where the horizontal forces occur the parallel V-shape will always ensure that at least two vibration attentuators concurrently with being extended somewhat sideways (shearing direction) also will be urged together into a smaller and smaller space. It can be said that they are forced into a wedge-shaped space and in such manner become progressive counterloads.

At each end of bottom plate 11 the V-shaped end plates 9 form a wedge-shaped space which increases outwards the closer towards the centre the end plates are welded or fastened by bolts. When the masses to be compacted are to be distributed by means of normal digging machine movements said space can never become too great. In order to improve this characteristic the end plates 9 are made as tall as possible. Furthermore, their upper portions are made to become engagement members against the projecting sections of the plate 1C in the upper portion 1 outside of the end legs 2 of the latter. In this manner a large volume of the compacting masses and relief of the vibration attenuators against heavy stresses in vertical directions become included in one and the same inventive concept.

As clarification it is to be mentioned that when the vibration attenuators are affected by forces which are parallel to their fastening plates 2 and 9, respectively, said forces are shearing forces. At that time the direction is the shearing direction. The end plates 9 are normally fastened at 90° with regard to the bottom plate and thus the vibration attenuators 10 are parallel to the end plates vertically, which makes their shearing direction correspond to the directional force of the vibratory unit so as to insulate the vibrations, whereby this direction also can be called the vibratory direction. Urging the vibration attenuators together is carried out in the direction of compression, i.e. 90 against the shearing direction and thus at right angles to end plate 9.

The difference in counterforce in the shearing direction and the compression direction, respectively, in one single vibration attenuator of a type which is used on a soil compacting machine of medium size is for example the following: In shear loading and a resilience distance of 25 millimetres 390 kilos;

In compression loading and a resilience distance of 25 millimetres - 2320 kilos.

The above illustrates the significance of the vibration attenuators being disposed properly with regard to the digging forces which necessarily are to be utilized in grading operations in connection with digging machine associated soil compacting.

Additional important characteristics of the bottom ends and the end legs of the upper portion of V-shape are the increased rigidness which this provides and which leads to making it possible to utilize plates having less thickness whereby the structure will have lower weight. It should be mentioned that present-time digging machines more and more are provided with a so-called roto tilt which is manufactured in a plurality of makes and embodiments. This is a good supplement even when a digging machine carries out soil compacting. The roto tilt makes it possible for an implement mounted on a digging machine to rotate around its own centre, and it is then of great significance that the above-mentioned progressiveness exists as horizontal digging forces can arise from an arbitrary line as the vibrator can in consequence of rotation have an arbitrary side against the heavy stresses of the digging machine in the direction of the digging force.

Furthermore, it should be mentioned that the V-profiles of the end plates 9 and the end legs 2 in the mentioned example are secured to the bottom plate 11 and to the upper portion 1 at right angles and that it is possible and in certain cases can become necessary to have end plates 9 and end legs 2 sloping a specific number of degrees in one or the other direction instead.

Finally, with regard to the case of "diagonal assembly with V-shaped profile" this can alternatively be utilized reversibly, i.e. with the end plates and end legs mounted concavely towards the centre, see Figure 4, and similarly to the first embodiment four or more vibration attenuators being mounted concavely, convexly or both.

Among the important characteristics which have been mentioned above is included that with the end plates mounted in V-shape one single rocking movement for example of the bucket cylinder of the digging machine can lend bottom plate 11 a sloping position in its longitudinal direction with regard to the horizontal plane so that it becomes fully cleaned of gravel and soil material which has to be done at regular intervals.

The invention is not restricted to the embodiments described above and illustrated in the drawings, and these merely comprise examples of the inventions and its mode of application.

Claims

1. A soil compacting vibrator comprising an upper portion (1) with a mount (1B) for a carrier arm, for example on a digging machine, and a lower portion (13) comprising a bottom plate (11) and a vibratory unit (8) driven by an hydraulic motor, with vibration attenuators (10), for example of rubber, being positioned between the upper portion (1) of the vibrator and its lower portion (13), c h a r a c t e r i z e d in that said vibration attenuators (10) are mounted essentially diagonally with regard to the bottom plate (11) of the soil compacting vibrator, that the vibration attenuators (10) are at each end of the bottom plate (11) connected on the one hand to end legs (2) which are fastened to the upper portion (1) of the vibrator, and on the other hand to end plates (9) which are fastened to the lower portion (13) of the vibrator, and that the mounting of the end legs (2) and the end plates (9) is carried out in such manner that they are mutually parallel in

V-shape having their tips either towards the outside of the vibrator or towards its inside.

2. A soil compacting vibrator in accordance with Claim 1, c h a r a c t e r i z e d in that said vibrator unit (8) has twin eccentric wheels and a directional centrifugal force.

3. A soil compacting vibrator in accordance with Claim 1, c h a r a c t e r i z e d in that the vibratory unit (8) is positioned diagonally on the vibrator and comprises one or more motors having hydraulic couplings and hoses as well as a connecting unit being protected by said upper portion (1) and end plates (9).

4. A soil compacting vibrator in accordance with any one of Claims 1 - 3, c h a r a c t e r i z e d in that the bottom side of the upper portion is embodied as an engagement surface for engaging the end plates (9) for stopping the movement of the upper portion (1) of the vibrator against the lower portion (13) for avoiding too great a load on the vibration attenuators.