DE102021004280A1 - Pneumatic hammer, rotary hammer, demolition hammer or rock drill - Google Patents

Abstract

The invention relates to a pneumatic hammer, rotary hammer, demolition hammer or rock drill suitable for construction site work or rock drilling. It has a drive system that powerfully pushes the chisel or drill along its longitudinal axis by igniting oxyhydrogen or butane gas. The device has fewer wearing parts, is very low-maintenance and, above all, does not have to be connected to a compressor, making it ideal for mobile use. It is environmentally friendly because it has a better energy balance than conventional devices. The variant with a hydrogen line system that feeds hydrogen into the chisel or drill bit and ignites the oxyhydrogen gas that is produced there can also drill through harder rock by weakening the material structure of the rock through micro-explosions.

Description

The invention relates to a compressed air hammer, rotary hammer, demolition hammer or rock drill with a new type of drive.

Air hammer, used in construction work, is a common device that uses a steel chisel powered by air pressure to break apart the structure or layers of asphalt. The drive comes from a large compressor, which is connected to the pneumatic hammer by a compressed air hose. The compressor is driven by an electric motor or an internal combustion engine. The chemical energy of the fuel is converted into mechanical energy in an internal combustion engine, which in turn is used for air compression. The compressed air is routed to the compressed air hammer using high-pressure hoses. A compressed air motor is installed in the compressed air hammer, which is able to convert the compressed air energy into mechanical energy. The compressed air energy is converted into mechanical movement by a sophisticated piston and valve system. The piston moves back and forth, hitting a bolt or directly on the chisels. This drives the chisel, which can be used to drill through concrete or harder ground.

This method has been used since the invention of the air hammer. Unfortunately, this method is accompanied by great energy losses. At least 70 percent of the losses in the conversion of chemical energy into mechanical energy are caused by the internal combustion engine alone. Further losses occur in the compressor and in the high-pressure hose line. The compressed air motor also causes further energy losses. In the end, only a fraction of the energy initially invested comes into its own. Although it is often used on construction sites, it is no longer up-to-date from an environmental point of view. It is very noisy and not very environmentally friendly. The compressor, if it is driven by an internal combustion engine, as is usually the case, produces exhaust gases that are not necessarily intended to be inhaled. Use in closed rooms is therefore not permitted. There are also electrically powered hammers that do not have the problem, but they are always tied to power lines, which are not always available, for example, when asphalt work is being done.

DE202017101783U1 describes a compressed air hammer in a compact form. The invention relates to a hand-held, vibration-damped pneumatic hammer in a compact and small design. Here, a handle is designed for at least partially manual guidance of the compressed air hammer and a piston housing which is connected to the handle at least mechanically and/or in terms of air flow and which has a compressed air chamber in which a piston is arranged so that it can move back and forth along a longitudinal axis of the compressed air chamber, the Compressed air hammer has air guiding means and piston return means, which are designed in such a way that when the compressed air hammer is operated, the piston can be moved in a working direction by means of compressed air, so that the piston delivers impact energy to a tool arranged on the compressed air hammer and that the piston, after delivering impact energy, the tool can be moved back against the working direction, in particular actively by the piston return means.

The patent specification EP 0 836 545 B1 discloses a pneumatic percussion tool having a tubular housing with a constant cross-section cylinder bore and a hammer piston reciprocably guided in the cylinder bore. The hammer piston has a neck area that delivers impacts. Valve means are provided for distributing drive air to the cylinder bore to move the hammer piston therein. A guide bushing is mounted in the cylinder bore for guiding an impact-receiving shank portion of a tool bit.

A cushion bushing is mounted in the cylinder bore behind the guide bushing for at least partially accommodating the neck portion of the hammer piston with each percussion stroke of the hammer piston.

The utility model document DE 20 2009 010 130 U1 discloses a handle for a hand-held implement. The holding handle is tubular and a tool part can be fastened to the holding handle. The support handle has at least one dimensionally stable basic tubular element and a damping device for damping shocks, impacts, impacts, oscillations or vibrations that are transmitted from the tool part to the support handle during use of the working device.

The invention specified in claims 1 to 10 is based on the problem of creating a pneumatic hammer that is environmentally friendly and works with good energy efficiency.

This problem is solved with the features listed in claims 1 to 10 for protection.

• - erhöhte Antriebs-Effizienz
• - hohe Schlagkraft und optimale Geschwindigkeiten erreichbar
• - zuverlässig
• - umweltfreundlich
• - kein Pressluftkompressor notwendig
• - einfach gebaut
• - weniger eingebaute Verschleißteile.

Advantages of the invention are:

• - increased drive efficiency
• - high impact and optimal speeds achievable
• - reliable
• - environmentally friendly
• - no compressed air compressor necessary
• - simply built
• - Fewer built-in wearing parts.

• 1 ein Drucklufthammer, der mit Wasserstoff funktioniert,
• 2 eine Ausführung, die ein eingebautes Elektrolyse-Gerät aufweist,
• 3 den Aufbau eines Magnet-Befestigungs-Systems,
• 4 ein stationäres Elektrolyse-Gerät und den Griff mit Schock-Absorber,
• 5 die Variante, wobei der Kolben durch den Druck, statt nach unten, nach oben geschoben wird.

Embodiments of the invention are based on the 1 until 5 explained. Show it:

• 1 a pneumatic hammer that works with hydrogen,
• 2 a version that has a built-in electrolysis device,
• 3 the construction of a magnet fastening system,
• 4 a stationary electrolysis device and the handle with shock absorber,
• 5 the variant where the piston is pushed up by the pressure instead of down.

The compressed air hammer (or rotary hammer or percussion drill) 1 here is of compact design and is not coupled to a compressor as is usual, but uses the explosive force of a hydrogen and oxygen mixture to powerfully move a piston. It is equipped with a drive system that allows for a compact design. The drive system from the invention is also ideally suited for rotary hammers or rock drills. These could achieve very high impact with the new drive. Of course, the new drive could also be combined with the ones already in use in order to increase efficiency without major changes.

The drive element is installed directly in the compressed air hammer and consists of a combustion chamber 2 in which oxyhydrogen or butane gas 3 is ignited and in which at least one movable piston 4 is installed. The piston is connected to the chisel 6 directly or via a lever/piston rod 5 or pin. The amount of hydrogen consumed per ignition varies depending on the size of the air hammer. For small devices, a few ^cc are sufficient, while for large devices, tens or more ^{cc of} hydrogen are consumed per cycle. The oxyhydrogen can expand up to 1000 times in volume when ignited. One of the devices is also called a compressed air hammer here because it is basically the same device, but the way it works is no longer given by air pressure, but by explosions of the portioned amounts of oxyhydrogen.

Two options are explained. One of them is to use a storage tank 7 with hydrogen 8 as fuel for a piston drive of the compressed air hammer, with the hydrogen being produced in a stationary or mobile electrolysis device 9 . The second variant generates the hydrogen through electrolysis immediately before use in a small electrolysis device that is installed directly in the pneumatic hammer. in that case, the electrolysis device, which is partially or completely filled with water 10, would have to be installed next to the combustion chamber. Two electrodes 11 are immersed in the water and are supplied with direct current from a low-voltage source/accumulator 12 . The water is provided with an electrolyte that increases the conductivity of the water. Electrolysis takes place in the water, through which the water is split into its components. The electrolysis device is installed directly under the combustion chamber 2 and is connected to it by a check valve 13 . The hydrogen and oxygen are fed into the combustion chamber, where the oxyhydrogen 3 is formed. Two high-voltage electrodes 14 are installed in the combustion chamber. These are coupled to a high-voltage generator 15 or a high-voltage generator. An electronic controller 16 regulates the ignition timing precisely. You can also trigger the ignition manually, e.g. using a switch, but in continuous operation the electronic control has a clear advantage because it can control ignition processes quickly and as often as you like. The ignition causes the oxyhydrogen to expand and the piston to move downwards. A return spring 17 returns the piston to its initial position. The piston can always touch the chisel 6, be firmly coupled to it by detachable connection, e.g. magnets or screws, or it can hit the chisel after a small distance. In this way, the chisel is accelerated in such a way that it drills into the material 18 to be machined. The air in the space can escape through a ventilation grille 45 and enter when there is a vacuum.

The piston can also be moved upwards by the explosive force of the oxyhydrogen gas, thereby pressing a strong spring 19 or compressing a quantity of compressed air 42 into an air chamber 43 via the piston and when the pressure force from the combustion chamber 2 decreases, the strong spring 19 or the compressed air pushes the piston down and then hits the chisel ( 5 ). The combustion chamber 2 here is installed below the compressed air chamber 43 . As the piston 4 moves upwards into the combustion chamber 2 due to the explosion pressure, it reaches a position where a pressure Compensation channel is opened and the water vapor flows out of the combustion chamber to the outside. This reduces the pressure in the combustion chamber immediately and the spring 19 or the compressed air in the compressed air chamber or a compressed air / gas pressure spring 44 specially installed for this purpose pushes the piston 4 downwards with high acceleration. The piston rod hits the chisel and pushes it down.

On the 3 a magnetic system has been shown which is intended to hold the chisel in the guide tube 33. Here magnets 37 are built into the wall of the guide tube and a ring magnet 38 in the bit. As soon as the chisel 6 is inserted into the guide tube 33, it is held retracted in one position. Each time the bit is pushed down and the piston moves up again, the bit is brought into the same position by magnetic force and positioned there by magnets.

On the 4 a variant with an external electrolysis device has been shown. The electrolysis device 9 generates hydrogen, best through a solar module 24 and conducts it in the pneumatic hammer. The handles of the compressed air hammer, which are equipped with a vibration absorber, are also shown here. The handle is constructed having an outer shell 35 into which is nested an inner handle 40 which couples directly to the air hammer. Between the outer cover 35 and the inner handle 40 there is a shock absorber compound 39 (eg gel compound) which decouples the outer cover from the handle. As a result, the user no longer feels such strong vibrations, which can also be harmful to health.

In the variant with the built-in electrolysis device, the hydrogen is generated in the electrolysis chamber 20 and stored in a storage tank 7 . You can also equip the air hammer or the stationary electrolysis device with solar cells, so that when it is placed in the sun, the electrolysis process always remains active and the hydrogen slowly accumulates in the storage container. The hydrogen should be stored separately from hydrogen in the storage container and used for later work. You don't necessarily have to store the oxygen in stock, because you can also use it from fresh air, so a second storage container for the oxygen can be saved.

A further embodiment provides for the electrolysis device to be designed in the form of a second mobile or stationary device which is coupled to the pneumatic hammer with the aid of a hose. The hydrogen is generated in the device, which is then fed into the compressed air hammer. In this case, the electrolysis device would be much smaller and lighter (and therefore also portable) than the compressor would be in a conventional pneumatic hammer. The electrolysis device can also be designed in such a way that the hydrogen produced there is stored in a storage chamber 21 which is then removed and connected to the compressed air hammer.

The hydrogen supply is regulated by electrovalves or possibly injectors 22 or a small piston pump. The electronic control / control unit regulates the electrovalves. The fresh air will then be transported into the combustion chamber by the pump or by a time-synchronized valve control during a short low-pressure phase. After the combustion of the oxyhydrogen (hydrogen / oxygen mixture) while the product expands in the form of superheated steam and the piston moves downwards, there is a phase in which a short-term negative pressure is created in the combustion chamber. This is the phase in which fresh air can be sucked in by opening an air inlet valve 23, which is connected to the atmosphere by means of a pipe. In the next phase, all you have to do is add hydrogen and close the valves. The next ignition is then initiated when the piston has moved back and has somewhat compressed the gas mixture more or less. When compression has been achieved the gas mixture is electrically ignited and the piston moves down transferring the kinetic energy to the bit.

The high-voltage electrodes should be arranged very close to each other here, so that the spark can also be generated with a voltage that is not too high. The gas mixture consists of H ² and fresh air or the oxygen contained therein, which together forms a so-called oxyhydrogen gas. The amount of fresh air should be about three times or a little larger in volume than the hydrogen injected there. This enables better hydrogen combustion. It is known that the hydrogen molecules can only be burned completely if the corresponding number of oxygen molecules are present. As soon as the oxygen molecules are missing, the combustion of the hydrogen molecules stops abruptly. To ensure complete combustion, there must be enough oxygen molecules (atoms). If there are a little more oxygen molecules than necessary, it doesn't matter because the hydrogen can then be completely burned out. The fresh air intake can be automatic if an electrovalve is installed in the fresh air supply duct, that at the moment when there is a vacuum after the combustion tion has been created opens. Fresh air is sucked in by the negative pressure. A small pump can portion the amount of fresh air more precisely. Diaphragm pumps or piston pumps, for example, are very good for this purpose. The optimal amount of fresh air to be added to the gas mixture per cycle can easily be determined by chemical calculations and results from practical experiments, whereby an optimal gas mixture can be formed. The electric spark ignites the gas mixture. It explodes and expands into the combustion chamber. The piston is moved down and the chisel is also moved with full force.

The valves for the fresh air supply and the hydrogen line can be built in the form of closing flaps made of an elastic material, which function in a similar way to the heart valves of a heart. That would automate and largely simplify the work of the drive element.

The variant with the stationary electrolysis device can generate the hydrogen in an environmentally friendly way using wind power or solar energy. For example, a solar module 24 with 1.5 m ² could be sufficient. The hydrogen would then have to be filled into compressed containers and brought to the place of use. The compressed air hammer that works with this method would be much more compact and would not have any annoying hose connections to another device. In this case, it would be completely self-sufficient or wireless. Only when the hydrogen tank is empty does it have to be replaced. After all, with a hydrogen bottle, depending on how big it is and how much the hydrogen is compressed in it, you could work for a few dozen minutes or even hours without any problems.

The device that has been described here uses the hydrogen as a pure energy source that can be produced elsewhere in an environmentally friendly manner. Despite the disadvantages in terms of efficiency by separating the water into components, the invention can generally achieve better efficiency and convince with some advantages. Today's electrolysis devices work with about 60 - 90% efficiency, which is very good for our purposes.

The invention has numerous advantages over conventional drive methods: slightly lighter weight, simpler construction and, since a connecting hose is not absolutely necessary, easier handling. The impact force can be adjusted as required using the electronic control. Any material can be machined with this air hammer.

In one variant, the hydrogen is generated directly in the drive element, but it can also access hydrogen supplies that are continuously produced by solar panels in an electrolysis device during the day.

The drive element that is presented here for the air hammer can also be successfully used in a rotary hammer or rock drill. These could achieve very high impact with the new drive.

For successful use with harder construction substances, a pipe line or channel 25 can be installed directly in the chisel or alongside it, through which hydrogen is conducted directly in the material to be drilled and there at the chisel or drill tip 26 mixed with the fresh air and ignited by the electric spark. One or more fine nozzles 27 can be installed at the tip of the chisel, which are provided with small dents 28, like a golf ball, which act like micro-collecting funnels, whereby these Micro-funnel 29 keep the oxyhydrogen in the drilling area from rising, but these nozzles can quickly become clogged with the substance to be drilled. The structural integrity of the chisel can also be adversely affected by a bore (channel) along it. Thus, the idea of forcing the gas down at the side of the chisel through a high-pressure nozzle 30, which is connected directly to the reservoir by a line 36 and an injector 22, is more advantageous. The hydrogen that arrives at the tip of the chisel or drill mixes with fresh air there and forms an oxyhydrogen gas. The detonating gas can then be ignited with the help of an ignition system and the explosive force can break the stone or concrete structure or at least weaken the structure of the substance by forming micro-cracks. The dust particles or small stone fragments can be caught by the micro funnels and used as an abrasive again by the oxyhydrogen explosion thrust against the substance there. A small screen 31 made of a transparent material (eg tempered glass or plexiglass) inserted in the device (or the drill is inserted in the screen) can protect the user from splinters while not obstructing the view. In addition, an air suction device can be installed, which sucks up the fragments and transports them to the explosion tip/funnel of the nozzle. The nozzle is located in the funnel and is enveloped in a cloud each time oxyhydrogen gas is injected. In this case, the chisel or the drill is supplied with voltage by an electrical line 32 via a sliding contact 46 or a conductive rolling ball in the guide tube 33 . The electrical ignition spark can be conducted from the chisel tip or drill tip. A second Electrode 34 can be installed there, or in that case the earth itself can serve as the second electrode. A second electrode inserted on the floor can be helpful for this.

Of course, in all variants with hydrogen combustion, the optimal mixing proportion of hydrogen and oxygen or hydrogen and fresh air is taken into account or introduced. If there is too little oxygen in the gas mixture in the combustion chamber, the combustion process will not take place completely and the pressure energy will not develop optimally. The proportions and number of hydrogen molecules that combine with oxygen molecules to produce water (water vapour) and the proportion of oxygen in atmospheric air are well known. Therefore, an optimal mixing ratio is not difficult to calculate. The proportioning of the amount of hydrogen is ensured relatively easily by a valve control or injection device/injector. This can be designed, for example, in the form of an electrically driven syringe. This would inject a small amount of hydrogen into the combustion chamber, which previously had fresh air drawn in.

Reference List

1

Pneumatic hammer / rotary hammer / percussion drill

2

combustion chamber

3

oxyhydrogen or butane gas

4

Pistons

5

lever / piston rod

6

chisel

7

reservoir

8th

hydrogen

9

electrolysis device

10

Water

11

electrodes

12

Low voltage source / battery

13

check valve

14

high voltage electrode

15

high voltage generator

16

Electronic control

17

return spring

18

Material to be processed

19

Strong spring

20

electrolysis chamber

21

hydrogen

22

injectors

23

air inlet valve

24

solar panel

25

pipe conduit or duct

26

Chisel or drill bit

27

Fine nozzles

28

Small dents

29

micro funnel

30

high pressure nozzle

31

Clear screen

32

Electrical line

33

guide tube

34

Second electrode

35

outer shell of the handle

36

Line from pantry

37

Magnet on the guide tube

38

magnetic ring

39

Vibration absorber on the handle

40

inside handle

41

pressure equalization channel

42

compressed air

43

compressed air chamber

44

Pneumatic spring / gas pressure spring

45

ventilation grille

46

Sliding contact or conductive rolling ball

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 202017101783 U1 [0004]
• EP 0836545 B1 [0005]
• DE 202009010130 U1 [0007]

Claims (10)

Pneumatic hammer, rotary hammer, percussion hammer or rock drill, characterized in that it is equipped with a drive element instead of an electric or compressed air drive, which consists of at least - a storage tank filled with hydrogen or another fuel gas, - a Combustion chamber that can be filled with hydrogen or another combustible gas and fresh air, - an injector or pump system, which is connected to the storage tank and combustion chamber and directs portioned quantities of hydrogen or gas and fresh air into the combustion chamber, - an ignition system -System that generates an electric spark through electrodes in the combustion chamber and ignites the gas mixture there, - an electrical or electronic control, which is coupled to the ignition system and a built-in energy source, - a piston, which is built into the combustion chamber is coupled to a piston rod which can be slid into a barrel or tube containing a tit l or drill pushes in the longitudinal axis or hits it or on which the kinetic energy is transferred Pneumatic hammer, rotary hammer, demolition hammer or rock drill Claim 1 , characterized in that the electrical or electronic control is coupled to an adjustable controller with which the amount of hydrogen or gas that is fed into the combustion chamber can be portioned as desired or according to work requirements. Pneumatic hammer, rotary hammer, demolition hammer or rock drill Claim 1 or 2 , characterized in that it has a water chamber installed under the combustion chamber, equipped with electrolysis elements consisting of one or more electrodes coupled to the inner wall of the water chamber, directly immersed in the water and an electrolysis of the water, which are placed in such a way that rising gases from the electrolysis are collected in the combustion chamber. Pneumatic hammer, rotary hammer, percussion hammer or rock drill according to one of the preceding patent claims, characterized in that the piston is not moved in the direction of the chisel / drill but in the opposite direction by the explosive force of the gas and it is connected to a spring system consisting of a spiral spring or gas spring that pushes back the piston in the direction of the chisel/drill hitting it with the piston rod. Pneumatic hammer, rotary hammer, percussion hammer or rock drill according to one of the preceding patent claims, characterized in that it has at least one channel which is built into the chisel or along the drill through which hydrogen or butane gas is injected with the aid of the injector up to the chisel or auger tip is pumped in, and an electrical connection is provided via the electrical or electronic controller that briefly applies high voltage to the chisel or auger, igniting the hydrogen or butane gas. Pneumatic hammer, rotary hammer, demolition hammer or rock drill Claim 5 characterized in that it has an electrode which can be stuck into the ground and which completes the circuit via the tip of the chisel or the drill. Pneumatic hammer, rotary hammer, demolition hammer or rock drill Claim 5 or 6 , characterized in that the chisel or the drill is equipped with at least one dome-shaped dent in which the channel for the hydrogen or gas opens out. Pneumatic hammer, rotary hammer, percussion hammer or rock drill according to one of the preceding claims, characterized in that - the combustion chamber is installed under the piston and the piston is pushed up instead of down, - a pressure equalization opening or channel in the side wall of the combustion chamber, which is only uncovered when the piston has completed a certain path upwards, through which the water vapor produced by the ignition can escape into the combustion chamber when the piston position is reached, - a reset mechanism via the piston Steel spring or compressed air spring is installed, which pushes the piston back down and hits the chisel or drill with its piston rod as soon as the pressure in the combustion chamber is reduced. Pneumatic hammer, rotary hammer, percussion hammer or rock drill according to one of the preceding claims, characterized in that it is equipped with a handle consisting of an outer sleeve, an inner lever which is directly connected to the pneumatic hammer, rotary hammer, percussion hammer or rock drill is, as well as a shock-absorbing mass, which is inserted between the outer shell of the handle and the inner lever builds and absorbs the mechanical vibrations of the inside lever Pneumatic hammer, rotary hammer, percussion hammer or rock drill according to any one of the preceding claims, characterized in that it is equipped with a magnetic support system for the chisel or the drill, consisting of at least one magnet built into the wall of the guide tube and a further magnet installed in the chisel or in the drill bit, whereby through magnetic field interaction between the two magnets, a positioning and return of the chisel or drill bit into the guide tube after each piston impact after the piston is retracted upwards, is initiated.

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