EP3889354B1 - Vibrating plate with hood optimized for noise reduction - Google Patents

Description

The present invention relates to a vibratory plate for soil compaction.

Generic vibrating plates, plate vibrators or vibrating plates are, for example, from DE 10 2012 017 777 A1 , the DE 20 2016 005 059 U1 , the DE 299 20 177 U1 and the EP 3 491 193 A1 known to the applicant. These are hand-held or remote-controlled machines that are used to compact soil material such as asphalt, sand, gravel or earth. They typically have a drive motor, for example an internal combustion engine, which runs on petrol, diesel or natural gas. For example, single-cylinder engines are common. Alternatively, electric motors can also be used. The drive motor is used, for example, to drive an exciter unit. This typically includes at least one imbalance which is rotated by the drive motor. This can be done, for example, with the interposition of a suitable gear. The actual ground contact is made using a base plate. The excitation unit can be mounted on the base plate. A support plate or a machine frame, which carries the drive motor, can be connected to the base plate, usually via suitable buffer elements. A guide element, such as a guide drawbar or a guide bracket, can be articulated on the support plate. The base plate or ground contact plate of the vibrating plate can be made to vibrate with the aid of the exciter unit. In other words, dynamic forces are applied to the base plate when the vibrating plate is in operation, as a result of which the subsoil is compacted. The maximum amplitudes of the resulting oscillating movement can be directed and adjustable in order, for example, to achieve self-propulsion of the vibrating plate.

A not inconsiderable level of noise is generated by the drive motor, particularly in the case of large and heavy vibrating plates. For this reason, it is known to equip the vibrating plates with a hood, also simply referred to below as a hood. However, since the drive motor has to be accessible regularly for maintenance purposes, the hood is normally adjustably mounted on the machine frame of the vibrating plate. It can be adjusted, for example, between an operating position that at least partially and in particular essentially covers the top and to at least several sides of the drive motor and a maintenance position that releases the drive motor at least partially, in particular upwards and to at least one of the sides. This includes, for example, both a linear displacement and a pivoting of the hood. The fact that the hood is adjustably mounted also includes the case in the present case, for example, in which the hood is detachably connected to the machine frame of the vibrating plate, for example via screw connections. To adjust the hood between the operating position and the maintenance position, it may be necessary to loosen one or more screw connections. The screw connections can be restored after the maintenance work. On the other hand, attachment of the hood to the machine frame of the vibrating plate via connections that have to be destroyed in order to adjust the hood is not included in the present case and is not regarded as "adjustable mounting" of the hood.

To cool the drive motor, cooling air is typically actively guided past the drive motor, for example the cylinder of the drive motor. However, the heated cooling air must then be guided out of the interior of the hood in a targeted manner, otherwise heat will build up under the hood. The vibratory plates of the generic type therefore typically have an exhaust air guide device for the cooling air of the drive motor, leading from the drive motor to an exhaust air opening in the hood. The task of the exhaust air guide device is to transport the heated cooling air, i.e. the exhaust air, from the drive motor through the interior of the hood in a targeted, spatially delimited and directed manner to the exhaust air opening of the hood, through which the exhaust air can escape to the outside environment. The exhaust air guide device typically comprises a single funnel-shaped or trumpet-shaped molded part, which is attached to an outlet opening for the exhaust air on the drive motor and extends through the interior of the hood to the exhaust air opening. However, this prior art design suffers from several disadvantages. For example, the structure-borne noise of the drive motor is transmitted to the exhaust air guide device, which emits it through the exhaust air opening to the outside (loudspeaker effect). In addition, the exhaust air deflection device cannot be dimensioned arbitrarily large because, on the one hand, the available attachment points on the drive motor are not sufficient for a to store heavy weight, and on the other hand, since the exhaust air guide must not hinder the adjustment of the hood between the operating and maintenance position. Due to the small dimensions of the exhaust air guide, it is impossible to line it with sound-insulating elements, for example, or to use particularly heavy materials for the exhaust air guide that would transmit less structure-borne noise. Conventional exhaust air deflectors have therefore made little contribution to reducing noise emissions from vibratory plates.

Also for the exhaust gases of the drive engine, an exhaust gas opening is typically provided in the hood, through which the exhaust gases are conducted to the outside environment. The exhaust pipe in the interior of the hood typically takes place via the exhaust of the drive motor, which is brought up to the exhaust gas opening in the hood, for example. In this area of the exhaust gas opening, too, there is a considerable emission of noise to the outside environment. There is therefore an overall desire to be able to operate vibratory plates more quietly.

The object of the present invention is to specify a vibratory plate with reduced noise emissions. At the same time, the handling comfort should not be reduced.

The task is solved with a vibrating plate according to the independent claim. Preferred developments are specified in the dependent claims.

Specifically, the solution is achieved with a vibratory plate of the generic type mentioned at the outset in that the exhaust air guide device is designed in two parts and includes an exhaust air adapter on the drive motor side and an exhaust air duct on the hood side, the exhaust air adapter and the exhaust air duct together forming a continuous exhaust air path from the drive motor to the exhaust air opening in the hood when the hood is in the operating position. The exhaust air adapter, on the one hand, is fastened to the drive motor and, in particular, is arranged in a stationary manner on it. The exhaust duct, in turn, is attached to the hood in such a way that it can be adjusted with the hood between the operating position and the maintenance position. The exhaust air duct is therefore arranged on the hood in particular in a stationary manner with respect to the hood. This can even go so far that the exhaust air duct is designed in one piece with the hood and/or is an integral part of the hood. In particular, the exhaust air guiding device consists exclusively of the two parts exhaust air adapter and exhaust air duct, which span the entire distance from the drive motor to the exhaust air opening. Both the exhaust air adapter and the exhaust air duct each represent a duct section that conducts or guides the exhaust air flow. The two duct sections merge into one another in the operating position. The duct sections each have an input and an output for the exhaust air. About the entrance of the exhaust air adapter, the exhaust air coming from the drive motor enters the exhaust air adapter. The outlet of the exhaust air adapter is in turn arranged in such a way that when the hood is in the operating position it rests against the entrance of the exhaust air duct or at least opens into the entrance of the exhaust air duct, so that the exhaust air coming from the exhaust air adapter enters the exhaust air duct through the inlet of the latter. The exhaust air is then routed through the exhaust duct on the hood side to its outlet, which is at the exhaust vent of the hood through which the exhaust air can eventually escape to the outside environment. The exhaust air opening of the hood is explicitly not part of the exhaust air guide device and also not part of the exhaust air duct. The exhaust air guiding device is designed to be as airtight as possible, so that the exhaust air flow is essentially completely guided by the drive motor to the exhaust air opening without escaping into the interior of the hood outside the exhaust air guiding device when the hood is in the operating position. Together, the exhaust air adapter and the exhaust air duct form the, in particular complete, exhaust air path for the exhaust air coming from the drive motor. When the hood is adjusted into the maintenance position, the exhaust air path is separated or opened, since the exhaust air adapter and the exhaust air duct are moved away from one another. Additional steps are not required, so that the overall handling comfort is not reduced. The exhaust air path is closed again when the hood is adjusted to the operating position. A core idea of the present invention is that the exhaust air guide device is attached to the drive motor to a significantly smaller extent than previously shown in the prior art. This smaller part is formed by the exhaust air adapter. On the other hand, a substantial part of the exhaust air guide device, in particular the larger part, is fastened to the hood and can be adjusted together with it. This part is formed by the exhaust air duct. The invention therefore aims at a further development of the hood of the vibrating plate, the hood being designed in such a way that the overall noise emission of the vibrating plate is reduced. The hood can absorb a significantly higher weight, so that the exhaust air duct on the hood side can be equipped with sound-insulating materials, for example, as explained in more detail below. A further advantage lies in the gain in space or installation space achieved in this way, because the hood now only has to be adjusted over a smaller internal volume formed by the drive motor and the part of the exhaust air duct on the drive motor side. This is particularly important when the hood can be pivoted between the operating position and the maintenance position.

The distance that the exhaust air has to cover through the exhaust air guiding device until it then escapes to the outside environment at the exhaust air opening of the hood is referred to here as the air duct path. The air duct section therefore extends from the drive motor or an inlet opening positioned downstream of the drive motor, in particular mounted directly on it, to the exhaust vent of the hood when the hood is in the operating position. In order to ensure comparability, the distance covered by the transported exhaust air with laminar flow, i.e. without turbulence or other detours, is considered to be the air duct distance. However, the air duct route does not have to run in a straight line and can also run around curves, for example, if the exhaust air guiding device requires a corresponding diversion of the exhaust air. In addition, the section that leads through the center of the clear width or the interior space of the exhaust air deflector is considered. The air duct route begins at the inlet of the exhaust air adapter and ends at the outlet of the exhaust air duct. Alternatively, the air duct distance can also be measured from the downstream end of the cylinder of the drive motor around which the flow occurs in the flow direction of the exhaust air to the passage of the exhaust air through the exhaust air opening of the hood. In order to use the noise-reducing effect of the invention as advantageously as possible, which results from the fact that the structure-borne noise of the drive motor is only transmitted to a smaller proportion of the exhaust air deflection device and therefore radiates less into the outside environment, it is preferable for the exhaust air duct to have the largest possible Proportion of the exhaust air duct accounts for. Conversely, the proportion of the exhaust air adapter becomes smaller. For example, it is preferred if the exhaust air duct forms a larger proportion of the air duct path than the exhaust air adapter. Provision is preferably made for the exhaust air duct to form at least 30%, preferably at least 50%, particularly preferably at least 70%, of the entire air duct path through the exhaust air guide device between the drive motor and the exhaust air opening. In addition to the lower transmission of structure-borne noise, a larger proportion of the exhaust air routing also offers the possibility of providing sound-damping or sound-absorbing material over a larger part of the exhaust air guiding device, as will be explained in more detail below.

The exhaust air guiding device also has an internal volume which is defined by the inner walls of the exhaust air adapter and the exhaust air duct and by the access opening at or near the drive motor and the outlet opening. In addition or as an alternative, it is preferred if at least 10%, in particular at least 20% and very particularly at least 40% of this internal volume is accounted for by the exhaust air duct. It is optimal if the volume fraction formed by the exhaust air duct is greater than the volume fraction formed by the exhaust air adapter, in particular if the exhaust air duct forms at least 60% of the entire interior volume enclosed by the exhaust air guide device. This information preferably refers to the hood in the operating position.

The exhaust air device also has an inner wall surface or duct surface, which is formed by the area of the inner walls of the exhaust air adapter and the exhaust air duct. It is preferred if the exhaust air guiding device is designed in such a way that the surface of the exhaust air duct is at least 20% of the entire inner wall surface of the exhaust air guide device, in particular at least 30%. It is particularly preferred if the inner wall surface of the exhaust air duct is larger than the inner wall surface of the exhaust air adapter, in particular if the inner wall surface of the exhaust air duct makes up at least 60% of the entire inner wall surface of the exhaust air guide device. This information preferably refers to the hood in the operating position.

It can therefore be particularly preferred if the volume of the exhaust air guide within the exhaust air duct is larger than the volume of the exhaust air guide within the exhaust air adapter, in particular at least twice, preferably at least three times, particularly preferably at least four times as large. The greater the proportion of the exhaust air routing in the exhaust air guiding device, the more advantageously a noise reduction can be brought about with the present invention. In the present case, the total volume of the exhaust air guide means the sum of the volumes of the exhaust air adapter and the exhaust air duct. These volumes in turn relate to the interior spaces enclosed by these components. In particular, the support structure of the exhaust air adapter and the exhaust air duct is considered here, so that any sound-damping or sound-absorbing materials that may be present do not reduce the volume under consideration. The volumes of the exhaust air adapter and the exhaust air duct end with the respective openings of the inlets and outlets of these components for the exhaust air, which have already been described above. If the openings are in one plane, the volume is measured up to this plane. If, on the other hand, the openings have more complex shapes, so that their edges no longer lie in one plane, then the surface enclosing the volume can be assumed to be a surface that results when a virtual plane that is considered flexible is placed over the openings in such a way that it is in full contact with the edge of the openings. The surface that spans the opening should be minimally deformed, i.e. deviate as little as possible from a plane, depending on the shape of the opening.

Depending on the type of construction, the exhaust air from the air cooling of the drive motor can emerge from the drive motor on different sides of the latter. Typically, the exhaust exits a side of the propulsion engine that is not the same side as the propulsion engine's exhaust directs the exhaust gases out of it. In the case of vibratory plates, however, it is preferred that both the exhaust gases and the exhaust air exit at the front of the machine, that is to say on a side lying at the front of the machine in the forward direction, from this or from the hood. This is because the operator is typically behind the machine. Exhaust gases and the exhaust air should therefore be discharged on the side of the machine opposite the operator. In addition, the sides of the machine that are parallel to the forward direction, i.e. commonly the left and right sides of the machine, are unsuitable for discharging gases, since vibratory plates are often used are used in trenches and are therefore brought laterally very close to vertical obstacles. These would impede the corresponding exit of the exhaust air and exhaust gases. For these reasons, it may be necessary for the exhaust air guide device to adapt the flow direction of the exhaust air to the structural conditions by the shape of the exhaust air path in such a way that the exhaust air exits on the side of the hood lying in the forward direction of the machine. The flow of exhaust air is therefore not guided in a straight line from the drive motor to the outlet opening of the hood, but, for example, around at least one curve. This curve is preferably caused by the exhaust air flow. In particular, the hood-side exhaust air duct is designed in such a way that it changes the flow direction of the exhaust air at least once between the drive motor and the exhaust air opening, in particular by essentially 90°. For this purpose, the exhaust air duct has baffle surfaces, for example, which cause a deflection of the flow direction of the exhaust air. This further development also aims to make the proportion of the exhaust air routing in the exhaust air guide device as large as possible in order to maximize the noise reduction of the invention.

The exhaust air adapter preferably has a motor side for connection to the drive motor and a connection side for connection to the exhaust air duct. The motor side of the exhaust air adapter is typically connected to the drive motor using fastening elements such as screws or rivets. This connection exists regardless of whether the hood is in the service position or the operating position. The connection of the connection side of the exhaust air adapter to the exhaust air duct of the hood, on the other hand, consists, for example, in that the connection side of the exhaust air adapter with the outlet opening for the exhaust air rests on the exhaust air duct, in particular in such a way that the outlet of the exhaust air adapter rests on the inlet of the exhaust air duct. There is preferably no further connection between the exhaust air adapter and the exhaust air duct, for example by snap-in connections or the like. It is preferred that the connection side of the exhaust air adapter and an inflow wall of the exhaust air duct, which will be described in more detail below, are designed to complement one another in such a way that they rest closely against one another in the operating position of the hood. In order to make this connection as airtight as possible, it is also preferred that the connection side of the exhaust air adapter has a sealing profile or a sealing element (e.g. an elastomer or a brush seal) which rests against the exhaust air duct when the hood is in the operating position . The sealing profile has, for example, a sealing lip, which is formed, for example, from an elastic material, in particular plastic or rubber. The connection side of the exhaust air adapter with the sealing profile preferably rests against the exhaust air duct, in particular its inflow wall. In this way, the tightness of the exhaust air guide increased and ensures that no heat can build up under the hood due to warm exhaust air escaping from the exhaust air guide device.

In order to make the connection or connection of the exhaust air adapter to the exhaust air duct mechanically simple and yet particularly tight, it is preferred if the connection side of the exhaust air adapter is tilted at an angle relative to the vertical, which is in particular 5° to 15°, preferably 9° to 12° °, is. Such an inclined position, in particular in the specified angular ranges, means that the relative movement of the exhaust air adapter and the exhaust air duct to one another when the hood is adjusted between the maintenance position and the operating position takes place mechanically and in a particularly simple manner without the risk of the two components becoming wedged. The connection side of the exhaust air adapter is particularly preferably located in a plane which is tilted or set at an angle relative to the vertical and which is aligned parallel to the forward direction of the vibrating plate.

According to a preferred embodiment, the exhaust air duct has at least one inflow wall and one line wall. The inflow wall in turn preferably has a connection opening through which the exhaust air coming from the exhaust air adapter enters the exhaust air duct. The connection opening is therefore the entrance to the exhaust air duct. The duct wall, on the other hand, serves primarily to seal the exhaust air guide device and direct the exhaust air flow through the exhaust air duct. The line wall is therefore free of passage openings for the exhaust air. Provision is now particularly preferably made for the inflow wall and the line wall to be designed as separate components which are assembled one after the other. The assembly takes place in particular on each other and on the hood, for example first the line wall is attached to the hood and then the inflow wall is attached to the hood and the line wall. In this way, the exhaust air duct according to the invention can be produced in a particularly simple manner. In addition, the inflow wall and the line wall can act as stiffening elements on the hood, so that the hood can be made simpler overall by dispensing with conventional stiffening elements. The exhaust air ducting thus preferably has exactly three components for producing the ducting space, specifically a partial area of the hood, the duct wall and the inflow wall.

It can also advantageously be provided that the inner wall of the hood itself or a region thereof is part of the exhaust air duct and thus represents a boundary wall of the interior of the exhaust air duct. In this way, the number of components required can be reduced.

In order to create the tightest possible connection between the exhaust air duct and the exhaust air adapter, it is preferred if the inflow wall of the exhaust air duct is tilted or set at an angle relative to the vertical, which is in particular 5° to 15°, preferably 9° to 12° . In particular, this is the same angle by which the connection side of the exhaust air adapter is tilted in relation to the vertical. This ensures that the exhaust air adapter and the exhaust air duct lie tightly against one another in the operating position of the hood and that the hood can be adjusted without problems between the maintenance position and the operating position.

A further simplification of the structure of the exhaust air duct is achieved if, according to a preferred embodiment, the duct wall is arranged essentially at right angles to at least one wall of the hood and is fastened to it. Such a training is particularly quick and easy to produce and therefore inexpensive.

Due to the favorable production, it is also preferred that the inflow wall and the line wall are produced by bending flat blanks. The blanks, in turn, can be obtained, for example, by being punched out or cut out of panels. For example, the inflow wall and the line wall have tabs that are placed against the walls of the hood and are connected to them by means of fastening means, for example screws or rivets. All in all, the components of the exhaust air duct can be produced in a particularly simple and cost-effective manner.

In addition, it is preferred if the exhaust air duct is made from a rigid material, in particular from the same material as the hood, for example from sheet metal. This applies in particular to the inflow wall and the duct wall of the exhaust air duct. Sheet metal with an average thickness of 3 mm to 5 mm, for example 4 mm, is usually used for the hood. The exhaust air duct preferably has a comparable flexural rigidity. In this way, the exhaust air duct is excited only to a very small extent, if at all, by the structure-borne noise of the drive motor to oscillate, which in turn can then be released into the outside environment as sound waves via the exhaust air opening. In addition, this design creates a stable support structure that can be used, for example, to accommodate sound-damping or sound-absorbing material, as will be explained in more detail below.

Since the hood is typically made of a comparatively rigid material, as explained above, the exhaust air duct according to the invention can be further simplified in a preferred embodiment in that the exhaust air duct is formed by walls of the hood on at least one side, preferably on at least two sides . The hood is typically in the form of a substantially rectangular box that is open at the bottom. In particular, if the exhaust air duct is arranged in one of the upper corners of the hood, the side walls of the hood can advantageously also be used as walls of the exhaust air duct. "Top" here refers to the side of the machine facing away from the base plate of the vibrating plate, while "below" refers to the side of the machine facing the base plate of the vibrating plate. For example, at least the wall terminating the hood at the top and/or one of the side walls of the hood extending parallel to the forward direction of the vibrating plate can also be used to form part of the exhaust air duct. All of the two walls mentioned are preferably used to each form a part of the exhaust air duct. In contrast, in the direction of the wall of the hood closing the hood in the forward direction of the vibrating plate at the front, the exhaust air duct is designed to be open. With this open side, the exhaust air duct is attached to the wall of the hood lying in the forward direction of the vibrating plate in such a way that the interior of the exhaust air duct communicates with the exhaust air opening located in this hood wall and the exhaust air can escape through the exhaust air duct from the hood.

As already indicated, it is also preferred if the exhaust air duct at least partially has a lining, in particular arranged inside the exhaust air duct, with a sound-damping and/or sound-absorbing material, for example a plastic foam or a fleece. Since the exhaust air duct according to the invention is designed to be larger and more stable than that of the prior art and/or is carried by the hood, a relevant amount of such material can also be used. Preferably, the entire interior or the entire inner surface of the exhaust air duct is lined with a sound-damping or sound-absorbing material from its inlet for the exhaust air to its outlet for the exhaust air. The noise emission of the vibrating plate according to the invention is thereby reduced considerably in a cost-effective manner. Alternatively or additionally, it can also be provided that the exhaust air duct on the hood side is fastened to the hood at least partially by means of structure-borne noise insulating elements in an advantageous further development. These elements can include plastic or elastomer materials, for example. In addition, these elements can also be used to seal the hood-side exhaust duct from the rest of the interior Be formed hood and in particular compared to the engine, so that no heated exhaust air the temperature balance of the engine (under the hood) adversely affects.

As mentioned at the beginning, noises from the exhaust of the drive engine are also introduced into the external environment. The exhaust describes the entire exhaust system of the drive engine that is customary in the prior art and includes, for example, at least one catalytic converter and at least one silencer. The exhaust typically ends with the so-called tailpipe. In the prior art, it is provided, for example, that the tailpipe of the exhaust pipe is brought up to an exhaust gas opening in the hood, so that the exhaust gas is discharged from the exhaust pipe into the outside environment via the exhaust gas opening. Despite the at least one muffler typically present in the exhaust system, not inconsiderable noise emissions reach the outside environment. In order to also counteract these noise emissions by means of an additional or alternative development of the hood according to the invention, it is preferably provided that the vibrating plate comprises an exhaust gas guide device from an exhaust pipe of the drive engine to an exhaust gas opening in the hood, and that the hood has a damping connection piece which is attached in such a way the hood is arranged to be adjustable with the hood between the operating position and the maintenance positions. The damping connector is fastened to the hood, for example, in particular in a stationary manner, and encloses the exhaust gas opening of the hood. The damping connector is designed to conduct exhaust gas from the exhaust to the exhaust gas opening, the damping connector in the operating position of the hood at least partially surrounds the exhaust of the drive motor or is designed to run around it at a radial distance. The damping connector is designed, for example, as a ring and/or pipe piece and is made in particular from a rigid material, for example a sheet metal and in particular the same material from which the hood is also made. The damping connector forms part of the exhaust guide device and guides the exhaust gases of the drive engine from the exhaust to the exhaust opening of the hood. By providing the damping connection, the exhaust does not have to be routed directly to the exhaust gas opening of the hood, but can end in the direction of direction at the level of the damping connection, which can further reduce the transmission of structure-borne noise from the drive engine as noise emissions to the outside environment.

A further reduction in the noise emission can be achieved if the damping connector is at least partially lined with a sound-damping or sound-absorbing material, for example a plastic foam or a fleece. Here, too, it is preferred that the entire inner surface or the entire interior of the damping connector is lined with such a material.

Figur 1:

eine perspektivische Ansicht einer Rüttelplatte von schräg vorne;

Figur 2:

eine perspektivische Ansicht einer Rüttelplatte von schräg hinten;

Figur 3:

eine perspektivische Ansicht einer Rüttelplatte des Standes der Technik mit entfernter Haube von schräg vorne;

Figur 4:

eine perspektivische Ansicht einer Rüttelplatte des Standes der Technik mit entfernter Haube von schräg hinten;

Figur 5:

eine perspektivische Explosionsansicht zur Anbringung des Abluftadapters am Antriebsmotor einer Rüttelplatte;

Figur 6:

den Motor einer Rüttelplatte gemäß Figur 5 mit am Antriebsmotor montiertem Abluftadapter;

Figur 7:

eine Seitenansicht des Motors gemäß Figur 6;

Figur 8:

eine perspektivische Ansicht der Haube einer Rüttelplatte von schräg hinten und unten;

Figur 9:

eine perspektivische Ansicht der Haube einer Rüttelplatte von schräg hinten und unten mit teilweise montierter Abluftführung;

Figur 10:

eine perspektivische Ansicht der Haube einer Rüttelplatte von schräg hinten und unten mit montierter Abluftführung;

Figur 11:

eine perspektivische Ansicht der Haube einer Rüttelplatte von schräg hinten und unten mit Abluftführung und Dämpfungsstutzen;

Figur 12:

einen Querschnitt durch eine Rüttelplatte entlang der Schnittebene X aus Figur 7; und

Figur 13:

eine Detailansicht des Ausschnittes Y aus Figur 12.

The invention is explained in more detail below with reference to the exemplary embodiments shown in the figures. They show schematically:

Figure 1:

a perspective view of a vibrating plate obliquely from the front;

Figure 2:

a perspective view of a vibrating plate obliquely from behind;

Figure 3:

a perspective view of a plate compactor of the prior art with the hood removed, obliquely from the front;

Figure 4:

a perspective view of a plate compactor of the prior art with removed hood obliquely from behind;

Figure 5:

an exploded perspective view for attaching the exhaust adapter to the drive motor of a vibrating plate;

Figure 6:

the motor of a vibratory plate figure 5 with exhaust air adapter mounted on the drive motor;

Figure 7:

a side view of the engine according to FIG figure 6 ;

Figure 8:

a perspective view of the hood of a vibrating plate obliquely from behind and below;

Figure 9:

a perspective view of the hood of a vibrating plate obliquely from behind and below with partially assembled exhaust duct;

Figure 10:

a perspective view of the hood of a vibrating plate obliquely from behind and below with mounted exhaust duct;

Figure 11:

a perspective view of the hood of a vibrating plate obliquely from behind and below with exhaust duct and damping socket;

Figure 12:

a cross-section through a vibratory plate along the cutting plane X figure 7 ; and

Figure 13:

a detailed view of section Y figure 12 .

Components that are the same or have the same effect are denoted by the same reference symbols. Repeating components are not separately identified in each figure.

the Figures 1 and 2 each show a generic vibratory plate 1. This has a guide pole 2 with operating elements 3, via which an operator can control the vibratory plate 1. The guide tongue 2 is arranged at the rear end of the vibrating plate 1 in the forward direction a. In operation, the vibrating plate 1 is guided with a base plate 4 over the soil to be compacted, either in or against the forward direction a. The base plate 4 is made to vibrate by an exciter unit 27, for example an unbalanced vibration exciter, which is in particular mounted directly on it. The excitation unit 27 is of a in the Figures 1 and 2 covered by a hood 5 drive motor 9 (see Figures 3-7 and 12 and 13), which is typically an internal combustion engine. The drive motor 9 is mounted on a support plate 30 or a machine frame, which is connected to the base plate 4 via a damping element 31 in a manner known per se in the prior art. The hood 5 closes off the engine compartment from the outside and at least partially forms the outer skin of the vibratory plate 1. The hood 5 is fixed but detachable to the supporting frame of the vibratory plate 1 via fastening means 28/28′, specifically screw connections. Due to the fixed connection of the hood 5 to the rest of the vibrating plate 1, it can be raised, for example, via the single-point suspension 6 and therefore easily moved to the construction site. At the same time, the hood 5 can easily be adjusted for maintenance work in the engine compartment. For this purpose, the two rear fastening means 28 in the forward direction a are loosened, of course on both sides of the vibrating plate 1. The fastening means 28' at the front in the forward direction a can then be used as a swivel joint, so that the hood 5 can be pivoted about a horizontal swivel axis S, which is transverse to the forward direction a runs, can be pivoted forwards and upwards in order to at least partially release the engine compartment and in particular the drive motor 9 in this way. The in the Figures 1 and 2 shown position of the hood 5 corresponds to the operating position. In this position of the hood 5, the vibrating plate 1 can be operated. If, on the other hand, the hood 5 is pivoted as described above, it releases the engine compartment and the drive motor 9 at least partially and is in the maintenance position. In this position, maintenance work can be carried out inside the engine compartment. As also in figure 1 As can be seen, the front side of the hood 5 in the forward direction a comprises an exhaust air opening 7, which is provided for the cooling air of the drive motor 9 to exit, and an exhaust gas opening 8, which is provided for the exhaust gases of the drive motor 9 to exit.

the Figures 3 and 4 show a prior art vibratory plate with the hood removed. As a result, both the drive motor 9 and the fuel tank 10, which are normally covered by the hood, are visible. On the drive motor 9, an exhaust air duct 11 and an exhaust 12 are arranged, which are designed to the exhaust air and the exhaust gases of the drive motor 9 respectively Exhaust openings 7 or to direct the exhaust port 8 in the hood. The exhaust air shaft 11 is designed in the shape of a funnel or trumpet and is made of a plastic, for example. Since the exhaust air duct 11 is attached directly to the drive motor 9, the structure-borne noise of the drive motor 9 is transmitted very well to the less rigid plastic material of the exhaust air duct 11. This also begins to vibrate and transmits the structure-borne noise of the drive motor 9 very strongly as noise emissions due to its shape on the outside environment. The prior art exhaust duct 11 acts like a noise amplifier, so to speak. In addition, the exhaust air shaft 11 is completely fixed at only one end, specifically on the drive motor 9. The exhaust air shaft 11 must therefore not be too heavy overall, which is why it is not possible to arrange significant amounts of vibration-damping or vibration-absorbing material here. In addition, the exhaust air shaft 11 forms the entire exhaust air guiding device. Only a seal, which is optionally attached to the engine hood or the exhaust air duct 11, still forms an essential functional component of the entire exhaust air device. The seal prevents heated exhaust air from flowing into the space inside the hood. The present invention is based on this actual state and reduces the noise emissions in that the exhaust air guiding device is designed essentially in two parts, as described below.

the Figures 5-7 show the exhaust air adapter 13 according to the invention and its arrangement on the drive motor 9. The exhaust air adapter 13 has a motor side 14 and a connection side 15. The exhaust air adapter 13 is fastened to the drive motor 9 with the motor side 14 so that it receives the exhaust air coming from the drive motor 9 . In figure 7 it is shown that the exhaust air adapter 13 extracts the exhaust air directly from the heat exchangers 19 of the drive motor 9, for example the cylinder 18 (see figure 12 ), incoming. The exhaust air adapter 13 is connected to the drive motor 9 via fastening devices 17, for example screw connections. Between the motor side 14 and the connection side 15 , a cavity that forms an exhaust air path 16 extends inside the exhaust air adapter 13 . The exhaust air path 16 runs from an inlet for the exhaust air on the motor side 14 to an outlet from the exhaust air adapter 13 on the connection side 15. Altogether, the exhaust air adapter 13 forms a channel for the exhaust air and directs it from the drive motor 9 to the connection side 15. The outlet for the exhaust air on the connection side 15 is also equipped with a sealing element 26, for example a sealing lip. The flow direction of the exhaust air within the exhaust air adapter 13 is essentially horizontal and perpendicular to the forward direction a. In addition, the direction of flow of the exhaust air within the exhaust air adapter 13 is essentially perpendicular to the direction of flow of the exhaust gases in the exhaust pipe 12, in particular in the tail pipe of the exhaust pipe 12. The tail pipe of the exhaust pipe 12 is oriented parallel to the forward direction a in particular.

the Figures 8-11 show the modifications to the hood 5 according to the present invention. The representation from diagonally below and seen from behind in the forward direction a allows a look into the interior of the hood 5, which serves as the engine compartment in the assembled state. Since the exhaust air adapter 13 only spans a small part of the entire air duct route from the drive motor 9 to the exhaust air openings 7, it is proposed according to the invention to equip the rest of the air duct route with an exhaust air duct 20 (see figures 10 and 11 ) to bridge, which is attached to the hood 5 or integrated into it. The exhaust air duct 20 comprises a line wall 22 and an inflow wall 21. The inflow wall 21 has a connection opening 24 through which the exhaust air coming from the exhaust air adapter 13 is received in the exhaust air duct 20. The connection opening 24 therefore forms the inlet of the exhaust air duct 20. It is designed to complement the outlet of the exhaust air adapter 13 on its connection side 15. Overall, the inflow wall 21 and the line wall 22 form another compartment in the interior of the hood 5. This compartment is also formed by the walls of the hood 5 itself, in the exemplary embodiment shown specifically by the upper side of the hood 5 facing away from the base plate 4 in the assembled state and by the parallel to the forward direction a, the right side wall of the hood 5. The entire compartment formed by the exhaust air duct 20 in the interior of the hood 5 is designed to be essentially airtight, except for the connection to the engine compartment or the exhaust air adapter 13 via the connection opening 24 and the connection to the outside environment via the exhaust air opening 7. The latter comes about because the exhaust air duct 20, which is open to the front in the forward direction a of the vibrating plate 1, rests tightly against the front wall of the hood 5 in the forward direction a, which also has the exhaust air opening 7, in such a way that the Interior of the exhaust air duct 20 with d he exhaust port 7 communicates. As in the sequence of Figure 9 and Figure 10 shown, only the line wall 22 is mounted in the hood 5, the function of which is only the separation and sealing of the compartment of the exhaust air duct 20. Thereafter, the inflow wall 21 is assembled, both on the hood 5 and the duct wall 22. Both the inflow wall 21 and the duct wall 22 are formed from stamped and bent metal sheets with an average thickness of 4 mm. The hood 5 is also made from sheet metal of this type. Overall, this results in a very stable construction, so that the interior of the exhaust air duct 20 can be lined with a sound-damping or sound-absorbing material (see figure 13 ).

figure 11 also shows another aspect of the present invention. Concrete shows figure 11 a damping stub 25 which is arranged around the exhaust port 8 . The damping connection piece 25 is designed, for example, as a pipe connection piece and has a larger diameter than the exhaust pipe 12 of the drive motor 9 . The damping connection piece 25 is designed in such a way and the exhaust pipe 12 is arranged in such a way that the exhaust pipe 12 protrudes into the damping connection piece 25 when the hood 5 is in the operating position. In other words, the damping connector 25 partially accommodates the exhaust pipe 12 . It is designed to complement the exhaust pipe 12 and can therefore also take other forms than, for example, a round piece of pipe, as in the exemplary embodiment shown. Overall, the damping connection piece 25 therefore forms part of the exhaust gas guiding device and directs the exhaust gas coming from the exhaust pipe 12 to the exhaust gas opening 8 of the hood 5. In addition, the damping connection piece 25 is also lined with a sound-absorbing or sound-damping material.

the figures 12 and 13 show the interaction of the exhaust adapter 13 and the exhaust duct 20 when the hood 5 is in the operating position. For this is in figure 12 a cross section through the vibrating plate 1 including the hood 5 at the level of the X plane figure 7 shown. figure 13 again shows a detailed view of section Y from figure 12 . The cooling air of the drive motor 9 flows around the heat exchanger 19 of the cylinder 18 and then enters the exhaust air adapter 13 as exhaust air. Here it flows through the exhaust air path 16 and enters the exhaust air duct 20 on the connection side 15 of the exhaust air adapter 13 and through the connection opening 24, in which it flows through the exhaust air path 23 until it finally leaves the hood 5 at the exhaust air opening 7 and passes into the outside environment . The exhaust air duct 20 is designed in such a way that it deflects the exhaust air flow by approximately 90°, specifically from a flow direction that is horizontal and perpendicular to the forward direction a into a flow direction that is still horizontal but parallel to the forward direction a. In the situation shown with the hood 5 in the operating position, the exhaust air adapter 13 and the exhaust air duct 20 are in close contact with one another. The sealing element 26 on the exhaust air adapter 13 seals the transition of the exhaust air from the exhaust air adapter 13 into the exhaust air duct 20 . The connection side 15 of the exhaust air adapter 13 and the inflow wall 21 of the exhaust air duct 20 are designed to complement one another. In the present embodiment, they each lie in a plane that is parallel to plane E, as in FIG figure 13 shown so that they abut each other in the plane E. The plane E and thus also the connection side 15 and the inflow wall 21 enclose an angle W with a vertical V, which is 10°, for example. The vertical V is perpendicular to the planar main extent of the base plate 4. In other words, the connection side 15 and the inflow wall 21 are tilted by the same angle W with respect to a vertical V. In addition are the inflow wall 21 and the connection side 15 parallel to the forward direction a. This facilitates the adjustment of the hood 5 between the maintenance position and the operating position, in particular when the hood 5 is adjusted by a pivoting movement between these positions, as in the exemplary embodiment shown. figure 13 also shows an example of a piece of sound-damping or sound-absorbing material 29 with which the entire exhaust air duct 20 is lined.

The in the prior art according to Figures 3 and 4 In contrast to this, the exhaust air guide device formed by a single exhaust air shaft 11 is designed in two parts according to the invention, with the larger part being fixedly arranged on the hood 5 or integrated into the hood 5 . The main advantages are better adjustability of the hood 5 between the operating position and the maintenance position, an increase in the part of the exhaust air guide device attached to the hood 5, ie the exhaust air duct 20, which means that soundproofing material can be used. Due to the more rigid design of the exhaust air duct 20 in relation to the exhaust air shaft 11 and the structural separation from the drive motor 9, less structure-borne noise from the drive motor 9 is transmitted to the outside environment as a noise emission. In addition, the hood 5 according to the invention can be further developed with a damping connection piece 25 which reduces noise emissions from the exhaust pipe 12 .

Claims (15)

1. A vibrating plate (1) for ground compaction, comprising

   - a drive motor (9);

   - an exciter unit (27) driven by the drive motor (9), by means of which a base plate (4) can be set in vibration,

   - an adjustably mounted hood (5) which is adjustable between an operating position at least partially covering the drive motor (9) and a maintenance position at least partially exposing the drive motor (9),

   - an exhaust air guiding device leading from the drive motor (9) to an exhaust air opening (7) in the hood (5) for the cooling air of the drive motor (9),

   characterized in that

   the exhaust air guiding device is designed in at least two parts and comprises an exhaust air adapter (13) on the drive motor side and an exhaust air guide (20) on the hood side, the exhaust air adapter (13) and the exhaust air guide (20) together forming a continuous exhaust air path (16, 23) from the drive motor (9) to the exhaust air opening (7) in the hood (5) when the hood (5) is in the operating position,

   that the exhaust air adapter (13) is attached to the drive motor (9), and

   that the exhaust air guide (20) is attached to the hood (5) in such a way that it is adjustable with the hood (5) between the operating position and the maintenance position.
2. The vibrating plate (1) according to claim 1,
   characterized in that
   the exhaust air guide (20) forms at least 30 %, preferably at least 50 %, more preferably at least 70 %, of the total air guiding path through the exhaust air guiding device between the drive motor (9) and the exhaust air opening (7).
3. The vibrating plate (1) according to any one of the preceding claims,
   characterized in that
   the volume of the exhaust air guiding device within the exhaust air guide (20) is larger than the volume of the exhaust air guiding device within the exhaust air adapter (13), in particular at least twice, preferably at least three times, more preferably at least four times as large.
4. The vibrating plate (1) according to any one of the preceding claims,
   characterized in that
   the exhaust air guide (20) on the hood side is configured such that it changes the flow direction of the exhaust air between the drive motor (9) and the exhaust air opening (7) at least once, in particular by essentially 90°.
5. The vibrating plate (1) according to any one of the preceding claims,
   characterized in that
   the exhaust air adapter (13) has a motor side (14) for connection to the drive motor (9) and a connection side (15) for connection to the exhaust air guide (20), and that the connection side (15) comprises in particular an elastic sealing element (26) which rests against the exhaust air guide (20) when the hood (5) is in the operating position.
6. The vibrating plate (1) according to claim 5,
   characterized in that
   the connection side (15) of the exhaust air adapter (13) is tilted with respect to a vertical (V) by an angle (W) which is in particular 5° to 15°, preferably 9° to 12°.
7. The vibrating plate (1) according to any one of the preceding claims,
   characterized in that
   the exhaust air guide (20) has an inlet wall (21) and a guiding wall (22), the inlet wall (21) having a connection opening (24) through which the exhaust air coming from the exhaust air adapter (13) enters the exhaust air guide (20), and the inlet wall (21) and the guiding wall (22) being configured, in particular, as separate components which are mounted successively.
8. The vibrating plate (1) according to claim 7,
   characterized in that
   the inlet wall (21) of the exhaust air guide (20) is tilted with respect to a vertical (V) by an angle (W) which is in particular 5° to 15°, preferably 9° to 12°, and which is in particular the same angle (W) by which the connection side (15) of the exhaust air adapter (13) is tilted with respect to the vertical (V).
9. The vibrating plate (1) according to any one of claims 7 to 8,
   characterized in that
   the guiding wall (22) is arranged essentially at right angles to at least one wall of the hood (5) and is attached to it.
10. The vibrating plate (1) according to any one of claims 7 to 9,
    characterized in that
    the inlet wall (21) and the guiding wall (22) are made from flat blanks by bending.
11. The vibrating plate (1) according to any one of the preceding claims,
    characterized in that
    the exhaust air guide (20), in particular the inlet wall (21) and/or the guiding wall (22), is at least partially made of an inflexible material, in particular of the same material as the hood, for example of a metal sheet.
12. The vibrating plate (1) according to any one of the preceding claims,
    characterized in that
    the exhaust air guide (20) is formed on at least one side, preferably on at least two sides, by walls of the hood (5).
13. The vibrating plate (1) according to any one of the preceding claims,
    characterized in that
    the exhaust air guide (20) at least partially has a lining with a sound-damping or sound-absorbing material, for example a plastic foam or a non-woven fabric.
14. The vibrating plate (1) according to any one of the preceding claims,
    characterized in that
    the vibrating plate (1) comprises an exhaust gas guiding device from an exhaust (12) of the drive motor (9) to an exhaust gas opening (8) in the hood (5), and that the hood (5) comprises a damping socket (25) arranged on the hood (5) such that it is adjustable with the hood (5) between the operating position and the maintenance position, and which is configured to guide exhaust gas from the exhaust (12) to the exhaust gas opening (8), the damping socket (25) at least partially engaging around the exhaust (12) of the drive motor (9) in the operating position of the hood (5).
15. The vibrating plate (1) according to claim 14,
    characterized in that
    the damping socket (25) at least partially has a lining with a sound-damping or sound-absorbing material, for example a plastic foam or a non-woven fabric.

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