WO1996005945A1

WO1996005945A1 - Hydraulic percussion hammer

Info

Publication number: WO1996005945A1
Application number: PCT/FI1995/000429
Authority: WO
Inventors: Kari Meuronen; Timo Salmi; Veikko Janhunen
Original assignee: Bretec Oy
Priority date: 1994-08-19
Filing date: 1995-08-15
Publication date: 1996-02-29
Also published as: AU3224495A; FI943810A0; FI943810A

Abstract

The invention relates to a hydraulic percussion hammer for binding dust spreading during breaking work from the material to be broken to the surroundings. According to the invention, the hydraulic percussion hammer (1, 11) comprises at least one conduit (5, 15) for dust-binding agent connected to the hammer in such a way that in order to spray the dust-binding agent onto the target (4, 14) to be broken, the conduit (5, 15) for dust-binding agent is connected from one end to a tank (6, 18) for dust-binding agent, comprising an associated pumping means (7, 16) for supplying the dust-binding agent with high pressure to the conduit (5, 15) for dust-binding agent. Furthermore, at least one nozzle (8, 23) is attached to the opposite end of the conduit (5, 15) for dust-binding agent in order to direct the spray of dust-binding agent at least partly at the target (4, 14) to be broken around the tool (9, 21) of the hydraulic percussion hammer.

Description

Hydraulic percussion hammer

The invention relates to a hydraulic percussion hammer comprising associated means for binding dust created in breaking work in such a way that the spreading of the dust to the surroundings is substantially prevented.

With respect to the supply of energy, percussion hammers can be divided into two groups: hydraulic and pneumatic percussion hammers. Hydraulic percussion hammers are usually connected to the hydraulic systems of different work machines, wherefore they do not require any external source of energy. Hydraulic percussion hammers are thus power-operated and have a considerably greater impact energy than manually operated pneumatic percussion hammers, which also require a separate source of compressed air in order to work. A hydraulic percussion hammer comprises a hydraulically reciprocating piston delivering consecutive strokes through a tool on the object to be worked. The object of the strokes may be of stone, concrete, asphalt, frozen soil, or the like. A percussion hammer may also be used as a percussion mechanism of a rock drill, and for example in pile driving and tamping work. The strokes of a hydraulic percussion hammer usually create dust in the work area of the hammer, the dust spreading from the material to be broken to the surroundings and causing thus different dust problems. In order to reduce these problems water is sprayed onto the material to be broken either before the work is started or during the work, for example via a water conduit that is separate from the hydraulic percussion hammer. The aim of supplying water via a water conduit separate from the hydraulic percussion hammer is to bind the dust that has already been stirred up from the material to be broken. However, it is difficult to direct a separate water conduit in such a way that the dust could be bound substantially immediately after it has been created. When water is supplied to the material to be broken before the work is started, it is possible to moisten only the surface that has not yet been broken. The water supplied before the work thereby only affects the surface, wherefore this manner of supplying has very little significance for binding the dust stirred up from the material to be broken.

The formation of dust is also a problem with pneumatic percussion hammers. However, the area of use of pneumatic percussion hammers differs from hydraulic percussion hammers, since the former are manually operated and have a considerably smaller impact energy than the latter. Therefore the impact of pneumatic percussion hammers also affects a considerably smaller area than that of hydraulic percussion hammers. Pneumatic percussion hammers thus create considerably less dust than hydraulic percussion hammers. When a pneumatic percussion hammer is used, it is possible to reduce the spreading of the dust by directing the water intended for binding the dust at the very spot on which the impact is targeted.

US Patent 4,854,393 discloses a manually operated pneumatic hammer comprising associated means for supplying water or a mixture of water and air near the end of the tool in order to bind dust created during the work. The water or the mixture of water and air is supplied to the target at a high speed. The use of water in the device according to US Patent 4,854,393 is essentially bound up with the compressed air used by the hammer, since the water intended for binding the dust is supplied with the pressure of the compressed air utilized by the hammer. This type of water supply is suitable for pneumatic percussion hammers, but in hydraulic percussion hammers it is much more difficult to bind the dust created during the work due to the greater amount of dust alone.

The purpose of the present invention is to eliminate prior art drawbacks and to provide an improved and ecologically more beneficial hydraulic percussion hammer in which the dust spreading to the surroundings from the material to be broken can already be bound substantially when the dust is created. The essential characteristics of the invention are disclosed in the appended claims.

According to the invention, in order to bind the dust spreading from the material to be broken to the surroundings during breaking work performed with a hydraulic percussion hammer, the hammer comprises at least one conduit for dust-binding agent, provided with a nozzle that is directed at the target to be broken substantially close to the end of the tool of the hydraulic percussion hammer. The conduit for dust- binding agent is preferably attached from one end to a tank for dust-binding agent installed in a unit controlling the energy transfer of the hydraulic percussion hammer, so that the dust-binding agent is supplied from the tank to the conduit for dust-binding agent, preferably by means of for example a pumping device controlled with a direct-current motor.

Via the conduit for dust-binding agent, the dust-binding agent is preferably sprayed onto the target to the broken in such a way that the dust created in the target can be bound substantially before it spreads to the surroundings. According to the invention, the part of the conduit for dust-binding agent touching the hydraulic percussion hammer can be attached to the casing of the hammer, either to the outer surface or inner surface of the casing wall, or even inside this wall. The conduit for dust-binding agent can also be placed preferably at least partly inside the hydraulic percussion hammer. The nozzle provided in the conduit for dust-binding agent is preferably attached to the wall of the casing of the hydraulic percussion hammer or to the bottom plate of the hammer in such a way that the entire nozzle is installed inside the casing wall or correspondingly inside the bottom plate in order to protect the nozzle from strokes possibly occurring during the work or from other similar factors interfering with the operation of the nozzle. The nozzle is preferably directed in such a way that at least a part of the dust-binding agent is sprayed onto the material to be broken around the tool of the hydraulic percussion hammer. According to the invention, preferably a liquid, such as water, is used as the dust-binding agent. It is also possible to use a mixture of water and gas, for example water mist. The dust-binding agent is preferably conducted in a pressurized form through the nozzle connected to the conduit for dust-binding agent substantially close to the part of the tool of the hydraulic percussion hammer touching the target to be broken. Since the dust from the target to be broken is formed at the point where the tool and the target come into contact, the dust-binding agent supplied according to the invention advantageously prevents the dust from spreading to the surroundings.

It is possible to connect preferably several nozzles, used for spraying the dust-binding agent, to the conduit for dust-binding agent utilized for binding the dust created by the hydraulic percussion hammer according to the invention from the target to be broken. Utilizing for example two nozzles mounted on both sides of the tool of the hydraulic percussion hammer enables the spraying of the dust-binding agent preferably in such a way that the tool does not substantially block the dust-binding agent from spreading to different sides of the tool. The dust-binding agent can thus be advantageously sprayed onto the dust created from the target to be broken before the dust is harmfully spread to the surroundings.

In the following, the invention will be described in greater detail with reference to the accompanying drawing, in which Figure 1 is a side view of a preferred embodiment of the invention, in partial cross-section,

Figure 2 is a side view of another preferred embodiment of the invention, in partial cross-section.

According to Figure 1, a hydraulic percussion hammer 1 is attached to a unit 2 adjusting the hydraulic pressure of the percussion hammer. An inlet pipe 5 for water used as a dust-binding agent for dust spreading from the material 4 to be broken is mounted on the outer surface of the casing 3 of the hydraulic percussion hammer 1. The inlet pipe 5 is connected from one end to a water tank 6 installed in the adjusting unit 2 for hydraulic pressure. A pump 7 supplying pressurized water from the tank 6 to the inlet pipe 5 is installed in connection with the joint of the water tank 6 and the inlet pipe 5. A nozzle 8 is mounted on the opposite end of the inlet pipe 5, the nozzle 8 being preferably directed in such a way that it sprays the pressurized water bursting from the inlet pipe 5 substantially close to the end 10 of the tool 9 of the hydraulic percussion hammer used in the breaking work, and thus at least partly onto the material 4 to be broken around the tool end 10.

In Figure 2, a hydraulic percussion hammer 11 is connected to a unit 12 adjusting the hydraulic pressure of the percussion hammer. An inlet pipe 15 for the dust-binding agent for the dust spreading from the material 14 to be broken is mounted on the inner surface of the casing 13 of the hydraulic percussion hammer 11. The inlet pipe 15 is connected from one end to a pump 16 installed in the adjusting unit 12 for hydraulic pressure. The pump 16 is further connected to a mixing means 17, where water from a water tank 18 and air from an air conduit 19 are mixed together in order to form water mist. By means of the pump 16, the water mist used as the dust-binding agent is pumped in pressurized form into the inlet pipe 15. The inlet pipe 15 is branched from the opposite end in such a way that the water mist is conducted to two nozzles 23 installed in openings 22 formed in the bottom plate 20 of the hydraulic percussion hammer on opposites sides with respect to the tool 21. The nozzle 23 is preferably directed in such a way that it sprays the pressurized water mist bursting from the inlet pipe 15 substantially close to the end 24 of the tool 21 of the hydraulic percussion hammer used in the breaking work, and thus at least partly onto the material 14 to be broken around the tool end 24.

Claims

1. A hydraulic percussion hammer for binding dust spreading during breaking work from the material to be broken to the surroundings, c h a r a c¬ t e r i z e d in that at least one conduit (5, 15) for dust-binding agent is attached to the hydraulic percussion hammer (1, 11) in such a way that in order to spray the dust-binding agent onto the target (4,14) to be broken, the conduit (5,15) for dust-binding agent is connected from one end to a tank (6,18) for dust- binding agent, comprising an associated pumping means (7,16) for supplying the dust-binding agent with high pressure to the conduit (5,15) for dust-binding agent, and that at least one nozzle (8,23) is connected to the opposite end of the conduit (5,15) for dust-binding agent in order to direct the spray of dust-binding agent at least partly at the target (4,14) to be broken around the tool (9,21) of the hydraulic percussion hammer.

2. A hydraulic percussion hammer according to claim 1, c h a r a c t e r i z e d in that a mixing means (17) is installed in connection with the pumping means (7,16) in order to mix together two dust-binding agents that are in different states.

3. A hydraulic percussion hammer according to claim 1 or 2, c h a r a c t e r i z e d in that the nozzle (8,23) connected to the conduit for dust-binding agent is directed substantially close to the tool end (10,24) of the hydraulic percussion hammer used in the breaking work.

4. A hydraulic percussion hammer according to claim 1, 2 or 3, c h a r a c t e r i z e d in that the conduit (5,15) for dust-binding agent is connected to the outer surface of the casing (3,13) of the hydraulic percussion hammer, for the part where the conduit (5,15) for dust-binding agent touches the hydraulic percussion hammer (1,11).

5. A hydraulic percussion hammer according to claim 1, 2 or 3, c h a r a c t e r i z e d in that the conduit (5,15) for dust-binding agent is connected to the inner surface of the casing (3,13) of the hydraulic percussion hammer, for the part where the conduit (5,15) for dust-binding agent touches the hydraulic percussion hammer (1,11).

6. A hydraulic percussion hammer according to claim 1, 2 or 3, c h a r a c t e r i z e d in that the conduit (5,15) for dust-binding agent is formed inside the wall of the casing (3,13) of the hydraulic percussion hammer, for the part where the conduit (5,15) for dust-binding agent touches the hydraulic percussion hammer (1,11).

7. A hydraulic percussion hammer according to claim 1, 2 or 3, c h a r a c t e r i z e d in that the conduit (5,15) for dust-binding agent is placed at least partly inside the hydraulic percussion hammer (1,11).