Patent Description:
Generally, hydraulic breakers are installed and used in construction equipment such as excavators and strike chisels which are breaking tools using pistons of cylinders to break concrete, rock, and the like using striking power.

Meanwhile, due to stricter noise regulations at construction sites, construction equipment noise levels are also required to be displayed, and excavators, drawers, loaders, breakers, and the like are included as types of equipment required to display noise levels.

In addition, in order to conduct construction with a high degree of noise within a predetermined distance from a residential area, apartment houses, schools, hospitals, public libraries, and the like, soundproofing facilities should be installed before the construction begins.

In order to avoid such noise regulations, low noise level types of equipment are being developed for the breakers which are included as targets required to display noise levels according to the regulations.

<CIT> discloses a low-noise breaker, and <CIT> discloses a vacuum breaker including a guide for noise reduction.

In addition, <CIT> discloses a breaker including a striking space having a vacuum atmosphere. Document <CIT> discloses a reciprocating impact hammer with a vacuum chamber.

The disclosed breaker includes a cylinder in which a piston is provided to be reciprocally moved by a separate driving pump, a housing which is provided under the cylinder and is vertically hollow and in which a striking space is formed, a striking unit which is provided in the housing, seals the striking space at a lower portion of the striking space, and receives striking of the piston and of which a lower end portion strikes a striking target, and a vacuum unit which communicates with the striking space and adjusts an inner portion of the striking space to have a vacuum atmosphere so as to reduce noise during striking of the piston.

The vacuum breaker has a structure which adjusts the vacuum atmosphere in the striking space to reduce the noise, but, since the vacuum breaker is formed in a cylindrical shape, it is difficult to expect a noise reduction effect.

Particularly, since a chamber portion of the piston operated by a hydraulic pressure is exposed to the vacuum atmosphere, there is a problem that lubricant leaks into the striking space. In addition, the striking space is a space for reducing noise and does not significantly affect an increase in the striking power of the piston.

Meanwhile, <CIT> discloses a pile driver, and <CIT> discloses a pile driver including an active noise control device.

In addition, <CIT> discloses a vacuum breaker including a rod guide for noise reduction, and <CIT> discloses a hydraulic breaker with a low-noise vibration structure.

Although the disclosed vacuum breaker may reduce noise due to striking, but may not reduce the noise transmitted through a chisel, the noise due to a repulsive force when the chisel breaks rock, and the vibrations and noise generated by striking power transmitted to a main body of the breaker during striking of the piston and the chisel.

In addition, <CIT> discloses a low-noise hydraulic breaker. The disclosed hydraulic breaker includes a hydraulic cylinder, a piston installed in the hydraulic cylinder, a front head coupled to a lower portion of the hydraulic cylinder, a chisel which is installed in the front head and of which a lower end protrudes outward from the front head and is struck by the piston, a striking chamber which is formed in an upper end portion of the front head and in which a lower end of the piston and an upper end of the chisel are positioned, a moving path formed in the front head and connected to the striking chamber, a leak noise shielding unit which is positioned at a lower end of the front head and in which a dust/soundproof room is formed, and an actuator installed around the leak noise shielding unit.

The present invention is directed to providing a vacuum breaker capable of reducing noise generated due to striking power of a chisel due to a piston and a noise transmitted through the chisel and a breaker unit during striking.

The present invention is also directed to providing a vacuum breaker capable of operating while a chisel enters or exits a breaker housing so that vibrations and noise generated due to vibrations and a repulsive force of the chisel are reduced.

The present invention is also directed to providing a vacuum breaker capable of preventing overheating of a piston and a chisel by supplying external air for cooling to a vacuum chamber surrounded by a breaker housing and a striking chamber in which the chisel and the piston are struck.

One aspect of the present invention provides a breaker unit including a cylinder part having a piston which is reciprocally moved and a front head which slidably supports a chisel for breaking and includes a striking chamber for striking the chisel using the piston of the cylinder part, a breaker housing forming a vacuum chamber which surrounds the breaker unit to block noise, a vacuum generation unit which is installed on the breaker housing and maintains a vacuum state of the vacuum chamber, and a cooling unit which supplies external air to the striking chamber of the breaker unit surrounded by the breaker housing to cool a striking portion of the piston and a striking portion of the chisel and discharges the external air which has cooled the striking portions through the vacuum chamber so as to cool the breaker unit.

A supply hole through which the external air is introduced into the breaker housing may be formed in the cooling unit, an inlet hole may be formed in the front head communicating with the striking chamber, a connection pipe connecting the supply hole and the inlet hole may be provided, and a discharge hole may be formed in the front head so that the striking chamber communicates with the vacuum chamber, air for cooling is introduced into the striking chamber through the supply hole and the inlet hole, and a descending speed of a piston is increased by a vacuum pressure applied to the striking chamber.

A reciprocally moving cylinder which moves the breaker unit installed in the vacuum chamber in a forward or rearward direction in the vacuum chamber may be further provided on the breaker housing.

In addition, an oil leak prevention part, which prevents operation oil from leaking into the striking chamber due to a vacuum pressure applied to the striking chamber, may be further provided in the cylinder part.

Piston seals for close contact between a cylinder and an outer surface of the piston and vacuum seals which are installed to be spaced a predetermined distance from the piston seals and maintain a vacuum state may be installed in the oil leak prevention part, an oil groove in which a lubricant is stored may be formed in an inner surface of the cylinder between the vacuum seals and the piston seals, and an oil discharge pipe through which oil in the oil groove is discharged to the outside of the breaker housing or to a storage tank may be installed in the cylinder.

A vacuum breaker according to the present invention can increase an acceleration force of a piston of a cylinder part to increase striking power of a chisel using a vacuum pressure during operation, and since striking portions of the chisel and the piston are continuously cooled by external air, overheating of the chisel and the piston can be prevented.

Particularly, since noise generated when the piston strikes the chisel and noise transmitted to a breaker unit and a breaker housing due to a repulsive force of the chisel when rock is broken can be reduced, the vacuum breaker can be used in a place in which noise generation is regulated.

A vacuum breaker according to one embodiment of the present invention capable of reducing noise and improving striking power is illustrated in <FIG>.

Referring to the drawings, a vacuum breaker <NUM> according to the present invention includes a breaker unit <NUM> including a chisel <NUM> for breaking and excavating rock and a cylinder part <NUM> for striking the chisel <NUM> and a breaker housing <NUM> including a bracket part <NUM> coupled to a boom of an excavator and surrounding the breaker unit <NUM> to form a vacuum space <NUM> in which a vacuum state at a predetermined pressure is maintained.

Vibration reduction members <NUM>, which prevent vibrations generated during operation of the breaker unit <NUM> from being transmitted to the breaker housing <NUM> and resonance from being generated, are installed between an outer surface of the breaker unit <NUM> and an inner surface of the breaker housing <NUM> and support the breaker unit <NUM> with respect to the breaker housing <NUM>.

In addition, the vacuum breaker <NUM> includes a vacuum generation unit <NUM> for maintaining a vacuum atmosphere of a vacuum chamber <NUM> and a vacuum atmosphere of a striking chamber, which will be described below, and a cooling unit <NUM> for cooling the breaker unit <NUM> in addition to striking portions of the chisel <NUM> and a piston <NUM> in a striking chamber <NUM> by supplying external air into the striking chamber <NUM> and the vacuum chamber <NUM> using a vacuum pressure generated by the vacuum generation unit <NUM>. A chisel support <NUM>, which slidably supports the chisel <NUM> and prevents noise from being transmitted to the breaker housing <NUM> and the breaker unit <NUM> is provided on the breaker housing <NUM>.

A configuration of the vacuum breaker according to the present invention configured as described above will be described in more detail below.

The breaker unit <NUM> is installed in the vacuum chamber <NUM> with the plurality of vibration reduction members <NUM> installed in the breaker housing <NUM>. The breaker unit <NUM> includes the cylinder part <NUM> including the piston <NUM> reciprocally moved by a hydraulic pressure supply unit and a front head <NUM> which is coupled to the cylinder part <NUM>, in which the chisel <NUM> is slidably installed, and which includes the striking chamber <NUM> for striking the chisel <NUM> using the piston <NUM>.

A support <NUM> may be further provided on an inner circumferential surface of the striking chamber <NUM> to prevent the chisel <NUM> from moving upward.

Meanwhile, as illustrated in <FIG> and <FIG>, an oil leak prevention part <NUM> which prevents an operation oil from leaking into striking chamber <NUM> due to a vacuum pressure applied to the striking chamber <NUM> is further provided in the cylinder part <NUM>. In the oil leak prevention part <NUM>, piston seals <NUM> for close contact between a cylinder 21a and an outer surface of the piston are installed, and vacuum seals <NUM> which are installed to be spaced a predetermined distance from the piston seals <NUM> to prevent a vacuum pressure applied to the striking chamber <NUM> from being applied to an installation portion of the piston in the cylinder 21a are installed.

In addition, an oil groove <NUM> for storing a lubricant is formed in an inner surface of the cylinder 21a between the vacuum seal <NUM> and the piston seal <NUM>. An oil discharge pipe <NUM> for discharging oil in the oil groove <NUM> to the outside of the breaker housing <NUM> is connected to the cylinder 21a, and the oil discharge pipe <NUM> extends to the outside of the breaker housing <NUM> or is connected to a storage tank <NUM> installed in the breaker housing.

In addition, as described above, the breaker housing <NUM> surrounds the breaker unit <NUM> to form the vacuum chamber <NUM> between an outer circumferential surface of the breaker unit <NUM> and an inner circumferential surface of the breaker housing <NUM>. However, the present invention is not limited thereto, and the breaker housing <NUM> may also be installed to surround a part of the breaker unit <NUM>, that is, a part of the front head <NUM>, to form the vacuum chamber <NUM> around the striking chamber <NUM> of the breaker unit <NUM>.

The vibration reduction members <NUM> support the breaker unit <NUM> so that the breaker unit <NUM> is fixed or moved forward or rearward in the vacuum chamber <NUM> of the breaker housing <NUM>. As illustrated in <FIG> and <FIG>, in order for the vibration reduction members <NUM> to movably support the breaker unit <NUM> forward or rearward in the breaker housing <NUM>, the vibration reduction members <NUM> are fixed to the inner surface of the breaker housing <NUM>, and end portions of the vibration reduction members <NUM> are in contact with and slide on the outer surface of the breaker unit <NUM>. The vibration reduction member <NUM> may be formed of one material selected from a non-ferrous metal, rubber, or a synthetic resin, but is not limited thereto.

The vacuum generation unit <NUM> includes a discharge pipe <NUM> installed on the breaker housing <NUM> to be connected to the vacuum chamber <NUM> and a vacuum pump <NUM> connected to the discharge pipe <NUM>. The vacuum generation unit <NUM> may also be installed to directly vacuum the striking chamber <NUM> of the breaker unit <NUM>.

Meanwhile, the cooling unit <NUM> cools the piston <NUM> in the striking chamber <NUM>, a struck portion of the chisel <NUM> struck by the piston <NUM>, and the breaker unit <NUM> by introducing external air into the striking chamber <NUM> and the vacuum chamber <NUM> using a vacuum pressure applied to the vacuum chamber <NUM>.

A supply hole <NUM> for supplying external air, that is, cooling air, to the breaker housing <NUM> is formed in the cooling unit <NUM>, and an inlet hole <NUM> which communicates with the striking chamber <NUM> and through which the cooling air is introduced is formed in the front head <NUM> constituting the breaker unit <NUM>. The supply hole <NUM> and the inlet hole <NUM> are connected by a connection pipe <NUM>.

In addition, a discharge hole <NUM> is formed in the front head <NUM> constituting the breaker unit <NUM> to discharge the cooling air which cools the piston <NUM> and the chisel in the striking chamber <NUM> to the vacuum chamber <NUM> using the vacuum pressure applied to the vacuum chamber <NUM>.

Meanwhile, the chisel support <NUM>, which is installed in the breaker housing <NUM>, slidably supports the chisel <NUM>, reduces vibrations and noise, and reduces the noise from being transmitted to the breaker housing <NUM> and the breaker unit <NUM>, includes an inner support member <NUM> which is installed in a chisel housing 80a fixed to the breaker housing <NUM> and supports an outer circumferential surface of the chisel <NUM>, an outer support member <NUM> having an inner surface surrounding the inner support member <NUM> to be spaced a predetermined distance from an outer circumferential surface of the inner support member <NUM>, and a damping member <NUM> which is installed between the outer circumferential surface of the inner support member <NUM> and an inner circumferential surface of the outer support member <NUM> to block noise and reduce vibrations. The damping member <NUM> may be formed of at least one material selected from rubber, synthetic rubber, a synthetic resin, and a non-ferrous metal.

In addition, a plurality of sealing members <NUM> spaced a predetermined distance from each other are installed on an inner circumferential surface of the inner support member <NUM>, and at least one lubricant storage groove <NUM> is formed between the sealing members <NUM>. The lubricant storage groove <NUM> is formed along the inner circumferential surface to store a lubricant scraped from the outer circumferential surface of the chisel <NUM> by the sealing member <NUM>.

Meanwhile, as illustrated in <FIG> and <FIG>, the vacuum breaker <NUM> according to the present invention further includes a reciprocally moving cylinder <NUM> which moves the breaker unit <NUM> supported by the vibration reduction members <NUM> in the vacuum chamber in a forward or rearward direction. The reciprocally moving cylinder <NUM> is installed on the breaker housing <NUM> and may be formed as a hydraulic cylinder. When the breaker unit <NUM> is moved forward or rearward by the reciprocally moving cylinder <NUM>, the chisel <NUM> enters or exits the vacuum chamber <NUM> of the breaker housing <NUM>.

In addition, although not illustrated in the drawings, the cylinder part for striking the chisel <NUM> may be controlled using a pressure reducing valve when a breaker operates. In addition, a vacuum pressure of the vacuum chamber <NUM> may be maintained to maintain a vacuum of an inside of the striking chamber <NUM> and increase a descending speed of the piston <NUM>.

An operation of the vacuum breaker according to the present invention configured as described above will be described below.

As illustrated in <FIG> and <FIG>, the vacuum breaker <NUM> according to the present invention operates the breaker unit <NUM> of which an end portion of the chisel <NUM> is aligned with a breaking target portion of rock in a state in which the vacuum breaker <NUM> is installed on a boom <NUM> of an excavator <NUM>.

In such a process, as illustrated in <FIG>, a striking sound generated by the breaker unit <NUM> is blocked by the vacuum chamber <NUM>, which is divided by the breaker housing <NUM> and in which a vacuum pressure is maintained, and reduced or ceased. In addition, noise generated when the breaker unit <NUM> vibrates can be reduced by the vibration reduction members <NUM> installed between the breaker unit <NUM> and the inner circumferential surface of the breaker housing <NUM> and prevented from being transmitted to the breaker housing <NUM>, and since such vibrations occur in the vacuum chamber, the generation of noise due to the vibrations can be minimized.

Particularly, since the chisel support <NUM> which supports the chisel <NUM> is installed in the breaker housing <NUM>, vibrations of the chisel <NUM> are prevented from being transmitted to the breaker housing <NUM> and amplifying noise. In more detail, a repulsive force and vibrations in forward, rearward, and radial directions, which are generated when the chisel <NUM> is striking, can be absorbed by a damping member <NUM> between the outer support member <NUM> and the inner support member <NUM> and prevented from being transmitted to the breaker housing <NUM>.

In addition, in such a process, since a lubricant in the chisel support <NUM> is stored in the lubricant storage groove <NUM>, the lubricant can be prevented from leaking to an end portion along the outer circumferential surface of the chisel. In addition, since a vacuum state of the vacuum chamber <NUM> is maintained by the vacuum generation unit <NUM>, cooling air is supplied to the striking chamber <NUM> through the supply hole <NUM>, the connection pipe <NUM>, and the inlet hole <NUM>, and the supplied cooling air is discharged to the vacuum chamber <NUM> through the discharge hole <NUM> after cooling the piston <NUM> of the striking chamber <NUM> and the striking portions of the cylinder part <NUM> and the chisel <NUM>. The cooling air discharged to the vacuum chamber <NUM> is discharged to the outside through the discharge pipe <NUM> and the vacuum pump <NUM> after cooling the breaker unit <NUM>.

In this case, since a set vacuum pressure is continuously maintained in the vacuum chamber <NUM> by the vacuum generation unit <NUM>, the vacuum pressure is not decreased by the cooling air supplied through the supply hole <NUM>.

In addition, since the oil leak prevention part <NUM> which prevents an operation oil from leaking into the striking chamber <NUM> due to a vacuum pressure applied to the striking chamber <NUM> is provided in the cylinder part <NUM>, the operation oil of the breaker unit <NUM> can be prevented from being introduced into the striking chamber <NUM>.

That is, in a process in which the breaker unit <NUM> operates, as the vacuum pressure is applied to the striking chamber <NUM>, the operation oil may leak along an outer surface of the piston <NUM> and the inner surface of the cylinder 23a, and the operation oil is collected in the storage tank <NUM> through the oil groove <NUM> and the oil discharge pipe <NUM> or discharged to the outside. Accordingly, a problem generated due to the operation oil being leaked into the striking chamber <NUM> can be prevented. Particularly, wear states of the piston seal <NUM> and the vacuum seal <NUM> can be checked through a discharge amount of the operation oil discharged through the oil discharge pipe <NUM>.

Meanwhile, when the reciprocally moving cylinder <NUM> is installed in the breaker housing <NUM>, and the chisel <NUM> enters the vacuum chamber <NUM> in which a vacuum pressure is maintained, as illustrated in <FIG>, in a state in which the breaker housing <NUM> comes closer to rock, the reciprocally moving cylinder <NUM> operates, a part of the chisel <NUM> is positioned in the vacuum chamber <NUM> in which the vacuum pressure is maintained, and thus an effect of blocking noise due to striking and vibrations of the chisel <NUM> and noise generated by a reaction force due to breaking of the rock can be maximized.

As described above, in the vacuum breaker according to the present invention, since a vacuum pressure is applied to the striking chamber for striking the chisel using the piston, striking power can be maximized by increasing a descending speed of the piston, a striking sound due to the piston and vibrations generated due to vibrations of the chisel and the breaker unit can be reduced, and thus occurrence of civil complaints due to the noise can be prevented when work is performed even in a manner like the a conventional manner.

Claim 1:
A vacuum breaker comprising:
a breaker unit (<NUM>) including a cylinder part having a piston which is reciprocally moved and a front head which slidably supports a chisel (<NUM>) for breaking and includes a striking chamber for striking the chisel using the piston of the cylinder part;
a breaker housing (<NUM>) which surrounds the breaker unit to form a vacuum chamber for blocking noise;
a vacuum generation unit (<NUM>) which is installed on the breaker housing and maintains a vacuum state of the vacuum chamber; and chracterised by
a cooling unit (<NUM>) which supplies external air to the striking chamber of the breaker unit surrounded by the breaker housing to cool a striking portion of the piston and a striking portion of the chisel and discharges the external air which has cooled the striking portions through the vacuum chamber so as to cool the breaker unit.