KR20140142436A - Hydraulic breaker - Google Patents

Abstract

The present invention relates to a hydraulic breaker mounted on a heavy equipment such as an evacuator and is actuated by a hydraulic pressure. A valve performs a relative motion to the inner circumferential surface of the inner diameter of a cylinder and the outer circumferential surface of the outer diameter of a cylinder bush. A valve switch area scale is formed in a valve switch chamber where high and low pressure selectively applies to the valve. A valve inner diameter area scale is formed in a valve inner diameter chamber where pressure higher than a low pressure flow path and lower than a high pressure flow path applies during a preparation mode of a piston, and high pressure applies during operational mode of the piston. A relationship is formed as A_valve switch area scale > A_valve inner diameter area scale. If the valve switch chamber communicates with a cylinder low pressure chamber in order to form low pressure in the valve switch area scale, the piston should be in a preparation mode. If the valve switch chamber communicates with a cylinder switch chamber in order to form high pressure in the valve switch area scale, the piston should be in the operational mode. Low pressure should always apply to a valve upper chamber, applying to the top surface of the valve, and a valve lower chamber, applying to the bottom surface of the valve. The valve inner diameter chamber is formed between the inner circumferential surface of the inner diameter of the valve and the outer circumferential surface of the outer diameter of the cylinder bush. The outer circumferential surface of a large diameter unit of the piston can vertically reciprocate along the inner circumferential surfaces of the inner diameters of the cylinder and the cylinder bush.

Description

Hydraulic Breaker {HYDRAULIC BREAKER}

The present invention relates to a valve assembly for a hydraulic breaker, in which an impact force generated when a piston assembled so as to reciprocate upward and downward in a cylinder hits a chisel is transmitted to a crushing object which is in contact with an end of the chisel, To a hydraulic breaker for crushing an object.

These hydraulic breakers are mainly used for crushing concrete, digging stone in a stone mining site, demolishing a building, or piling a file at road construction.

Normally, a hydraulic breaker commonly used in the market strikes an upper end portion of a chisel in which the piston is in contact with the object to be crushed by the weight of the piston and the pressure acting on the piston so as to move up and down in the cylinder in the vertical direction. And transmits the impact force to an object to be crushed such as a rock, concrete or the like in contact with an end portion of the chisel to crush the crushed material. The crusher is operated by receiving hydraulic oil from a hydraulic power source provided in an excavator or the like.

The hydraulic breaker comprises a cylinder constituting a body portion of the hydraulic breaker, a piston provided in an inner central portion of the cylinder so as to be able to move up and down in a vertical direction, a lower end portion of the piston, And a front head portion provided at a lower portion of the cylinder and having the chisel inserted therein.

The cylinder constituting the body portion of the hydraulic breaker includes a plurality of flow paths through which hydraulic fluid discharged from a hydraulic power source provided in an excavator or the like is introduced or discharged, a cylinder provided in the inner side of the cylinder and connected to the flow path, And a valve for causing the piston to move up and down by selectively supplying the operating oil to the upper chamber and the cylinder chamber and the cylinder chamber, respectively.

The piston reciprocates between a top dead center and a bottom dead center in the cylinder by hydraulic pressure of hydraulic oil discharged from a hydraulic power source provided in an excavator or the like, and is configured to contact an upper end of the chisel at a bottom dead center.

The chisel transfers an impact force generated by a collision with the piston to the object to be crushed, and the piston is hit by the piston when the piston descends from the top dead center to the bottom dead center.

FIG. 8 is a sectional view showing a hydraulic breaker to which the prior art is applied, and FIG. 9 is a sectional view showing a valve shape applied to the hydraulic breaker shown in FIG.

As shown in the figure, the hydraulic breaker 10 includes a cylinder 20 installed so that the piston 24 is vertically moved up and down, and a chisel 94 installed in the lower portion of the cylinder 20 And a gas chamber 98 which is a closed space filled with gas such as nitrogen (N ₂ ) for providing a pressing force when the piston 24 is lowered is provided in the upper part of the cylinder 20 And a head 96.

A plurality of oil passages 76, 78, 80, and 82 are formed in the cylinder 20 so that hydraulic oil can be introduced and discharged from the outside. The piston 24 is vertically moved up and down A cylinder bushing 40 is provided on the same central axis as the in-cylinder diameter portion 22 and a piston 24 is provided at the center of the cylinder bushing 40. [ And a hydraulic oil supplied through a flow path formed in the cylinder 20 to move the piston 24 up and down between the outer surface of the cylinder bush 40 and the in-cylinder diameter portion 22 A valve 50 in the form of a cylinder for selectively interrupting or supplying the gas is provided movably in the up and down direction and a predetermined space between the in-cylinder portion 22 and the valve 50 is provided with a valve chamber 70 and a valve low pressure chamber 72 are provided.

The valve 50 of the hydraulic breaker 10 is formed in a cylindrical shape having a through hole 46 at a central portion thereof and is provided at an inner lower portion in contact with the outer surface of the cylinder bush 40 for a descending stroke of the valve 50 Pressure hydraulic pressure receiving surface 56 is formed at one side of the outer side and a valve high pressure hydraulic pressure surface 52 for applying the hydraulic pressure of the hydraulic oil to the up stroke of the valve 50 is formed And a valve inner diameter hydraulic pressure surface 54 in which a high pressure hydraulic pressure is applied during the descending stroke of the valve 50 and a low hydraulic pressure is applied during the ascending stroke of the valve 50 is formed in the inner middle portion.

10 and 11 are views showing the operation of the hydraulic breaker valve when the hydraulic breaker valve is lifted up and down. Referring to the figure, the piston (24) of the conventional hydraulic breaker (10) Nitrogen gas or the like is injected into the gas chamber 98 which is a closed space in the back head 96 coupled to the upper end of the cylinder 20 and the lower end of the piston 24 The chisel 94 is provided on the same line as the central axis of the piston 24. [

The upper end of the piston 24 is urged downward by the nitrogen gas pressure in the gas chamber 98 when the hydraulic breaker 10 is in the standby state for operation, The valve 50 is in the bottom dead center position in contact with the top surface of the valve body 94. At this time, the valve 50 is also placed at the bottom dead center position by self weight.

When the high pressure hydraulic fluid discharged from the external hydraulic power source flows into the cylinder 20 through the inlet port in a state where the piston 24 is placed at the bottom dead center position, And a high pressure is applied to the lower pressure receiving surface 28 which is the lower surface of the first large diameter portion 26 due to the high pressure hydraulic fluid supplied to the cylinder mouth 84. At the same time, Pressure hydraulic fluid introduced into the cylinder 20 is supplied to the valve 50 at the bottom dead center position via the separately formed second high-pressure flow path 78 to be supplied to the valve high-pressure hydraulic surface 52 and the valve inner- Pressure hydraulic pressure surface 52 is formed so as to have an area larger than the area of the valve inner-diameter hydraulic pressure surface 54. In this case,

The valve seat 74, which is in contact with the valve upper surface 70 of the valve 50 and the lower end surface of the valve 50, is in communication with the low pressure passage 82, The valve switching chamber 42 formed in a predetermined space between the outer surface of the cylinder bush 40 and the inner surface of the valve 50 is connected to the valve switching chamber orifice 58 and the switching chamber passage 80, The low pressure is applied to the valve switching pressure receiving surface 56 provided in the lower portion of the valve 50 so that the high pressure acting on the valve high pressure hydraulic pressure surface 54 acts on the valve 50, Is raised to the top point.

When the valve 50 is lifted up, the cylinder-loaded chamber 90 formed in the predetermined space between the outer circumferential surface of the piston 24 and the inner circumferential surface of the cylinder bushing 40 is disconnected from the second high-pressure flow path 78, Pressure passage 82 through the bush orifice 44 and the valve low-pressure chamber orifice 60, so that a low pressure is formed in the cylinder-

The lower pressure receiving surface 28 of the first large diameter portion 26 of the piston 24 located in the cylinder bore 84 by the high pressure hydraulic fluid supplied to the cylinder bore 84 through the first high pressure passage 76 A pressing force for lifting the piston 24 is applied to the gas chamber 98 of the back head 96 by a pressure of nitrogen (N ₂ When the piston 24 is raised, the piston 24 starts to rise and the upper portion 24 of the piston 24 (PU) The nitrogen gas in the gas chamber 98 is compressed to raise the gas pressure.

When the piston 24 continuously ascends and the lower pressure receiving surface 28 of the first large diameter portion 26 reaches the cylinder switching chamber 86, The conversion chamber flow path 80 and the valve switching chamber orifice 58 so that a high pressure is formed in the valve switching chamber 42. [

Here, the area of the valve high-pressure hydraulic surface 52 to which high pressure is applied due to the high-pressure hydraulic fluid supplied through the second high-pressure hydraulic path 78 is formed to have an area smaller than the area of the valve-switching hydraulic pressure surface 56 , When the high pressure is simultaneously applied to the valve high pressure hydraulic surface 52 and the valve switching hydraulic surface 56, the lower force applied to the valve switching hydraulic surface 56 is greater than the lift force applied to the valve high pressure hydraulic surface 52 And the valve is lowered.

When the valve 50 begins to descend, the cylinder chamber 90 is disconnected from the low pressure passage 82 through the cylinder bushing orifice 44 and the valve low pressure chamber orifice 60, and the valve high pressure orifice 62 is closed, Pressure fluid passage 78 through the cylinder bushing orifice 44 and the cylinder bushing orifice 44 so that the high-pressure operating fluid is supplied to the cylinder-

Since the area of the upper pressure receiving surface 32 of the second large diameter portion 30 of the piston 24 is larger than the area of the lower pressure receiving surface 28 of the first large diameter portion 26, The lower force applied to the upper pressure receiving surface 32 becomes larger than the upward force applied to the lower hydraulic pressure surface 28 so that the piston 24 is moved upward, Stopping the rise and descending.

When the piston 24 is lowered, a lower force is added to the gas chamber 98 by the compressed nitrogen gas, and the piston 24 descends at a higher speed than the piston 24 when the piston 24 is lowered, so that the piston 24 hits the chisel 94.

When the piston 24 descends and strikes the chisel 94, an impact force is generated. At this time, the generated impact force is transmitted to the object such as a solid ground or a rock which is in contact with the tip of the chisel 94, do.

When the lowering of the piston 24 is completed, the valve switching chamber 42 is communicated with the low-pressure flow passage 82 through the valve switching chamber orifice 58, the conversion chamber passage 8 and the cylinder conversion chamber 86, The lowering force applied to the valve 50 becomes smaller than the lift force so that the valve 50 is raised and the upward and downward operation cycles of the piston 24 are in the order of valve lift → piston lift → valve fall → piston descent It works repeatedly.

 The conventional hydraulic breaker 10 configured as described above is also raised to the top dead center when the piston 24 is in the standby mode in which the up stroke is performed. That is, the high-pressure hydraulic fluid supplied to the hydraulic breaker 10 is used not only for the upward stroke of the piston 24, but also for applying high pressure to the valve high-pressure hydraulic pressure surface 52 at all times.

In the working mode in which the descending stroke of the piston 24 is performed, a high pressure is formed in the valve switching chamber 42, so that the valve 50 is lowered. As a result, a high pressure is formed in the cylinder- The high pressure is also applied to the pressure chamber 54. The high pressure hydraulic fluid supplied to the hydraulic breaker 10 is supplied to the valve high pressure hydraulic surface 52 and the valve switching hydraulic pressure surface 56 and the valve inner diameter hydraulic pressure surface 54 as well as the descending stroke of the piston 24, .

In this conventional hydraulic breaker 10, a part of the hydraulic oil is used to lift the valve 50 when the piston 24 is in the standby mode in which the lifting stroke of the piston 24 is performed, The amount of the operating oil to be supplied to the piston 24 is reduced, thereby lowering the rising speed of the piston 24 and reducing the number of strokes.

Even in the operation mode in which the descending stroke of the piston 24 is performed, a part of the operating oil is supplied to all three valves (valve high pressure hydraulic pressure surface 52, valve switching hydraulic pressure surface 56 and valve internal pressure hydraulic pressure surface 54) The amount of the hydraulic fluid used to descend the piston 24 relatively decreases, so that the descending speed of the piston 24 may be lowered and the hitting force may be lowered.

That is, the structure of the valve 50 of the conventional hydraulic breaker 10 is supplied to the inside of the cylinder so that a part of the hydraulic fluid to be used for the operation of the piston 24 is diverted to maintain the high pressure on the pressure- Therefore, the number of hits and striking force of the piston 24 striking the chisel 94 may be reduced, and the output and efficiency may be reduced.

Although the crushing operation using the hydraulic breaker 10 is started at the beginning of the operation with the temperature of the operating oil being at normal temperature, when the operation is progressed and a predetermined time has elapsed, the sliding of the piston 24 and the valve 50, The temperature of the operating oil and the hydraulic breaker 10 is increased due to the friction generated when the piping flows. As a result, the nitrogen gas in the gas chamber 98 is expanded due to the temperature and the gas pressure is increased. The operating pressure is increased.

As the viscosity of the hydraulic fluid decreases, the clearance between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder, the clearance between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder bush and the clearance between the inner peripheral surface of the cylinder and the outer peripheral surface of the cylinder bush The leakage amount of the operating oil through the clearance and the clearance between the outer circumferential surface of the valve and the inner circumferential surface of the cylinder is increased and the leakage amount of the operating oil through the clearance increases as the operating pressure of the hydraulic breaker increases.

The operating oil supplied when the rising stroke of the piston 24 is performed in the preparation mode in which the leakage amount of the operating oil is increased as described above is supplied not only to the upward movement of the piston 24 but also to the valve Pressure hydraulic pressure surface 52 so that the amount of hydraulic fluid used in the upward stroke of the piston 24 is further reduced.

In other words, since the operating oil used for raising the piston 24 is reduced by the amount of operating oil used for the valve high pressure hydraulic surface 52 along with the oil leakage, the rising speed of the piston 24 is reduced so much that the number of strokes is lowered.

Further, when high-pressure operating fluid is supplied from the cylinder switching chamber 86 to the valve switching chamber 42 through the conversion chamber flow path 80 in a situation where the leakage amount is increased due to the increase of the operating oil temperature, a gap between the valve outer circumferential surface and the cylinder inner circumferential surface, , Leakage occurs in the clearance between the inner peripheral surface of the valve and the outer peripheral surface of the cylinder bush.

In a normal operating condition in which the valve (50) is lowered to perform the descending stroke of the piston (24), the piston (24) strikes the chisel (94) at the bottom dead center, The operating fluid supplied to the valve switching chamber 42 by the cylinder switching chamber 86 and the cylinder low pressure chamber 88 is communicated by the groove G formed between the neck portions through the low pressure passage 82 connected to the cylinder low pressure chamber 88 The pressure of the valve switching chamber 42 is lowered due to leakage of working oil through a plurality of leaking paths existing around the valve switching chamber 42 as described above, In some cases, the valve 50 may not be positioned at the bottom dead center until the piston 24 strikes the chisel 94, and may be raised.

When the valve is raised before the piston 24 hits the chisel 94 and the piston 24 is not positioned at the bottom dead center until the piston 24 hits the chisel 94, Pressure oil passage 82 and the operating oil in the cylinder-lowering chamber 90 is discharged through the low-pressure passage 82, the descending speed of the piston 24 is greatly reduced, and the hitting force is lowered.

SUMMARY OF THE INVENTION The present invention has been proposed in order to solve the problems of the prior art described above, and the operating oil supplied when the piston is in the preparation mode in which the lifting stroke of the piston is performed is not used for lifting the valve but is used only for lifting the piston, The hydraulic oil supplied in the work mode is used for maintaining the high pressure of the two hydraulic pressure surfaces such as the piston descent and the valve switching hydraulic pressure surface V1 and the valve inner diameter hydraulic pressure surface V2, By avoiding the area where the hydraulic oil is used to maintain the high pressure on the high pressure hydraulic surface (V3), the piston does not lower the rising speed of the piston when it is in the preparation mode and only the minimum necessary hydraulic oil So as not to lower the rate of descent of the piston, To provide a breaker for that purpose.

In addition, when the operating oil temperature rises and the operating pressure of the hydraulic breaker rises, the leakage path around the valve switching chamber is minimized to reduce the pressure drop in the valve switching chamber due to leakage in the vicinity of the valve switching chamber, And it is an object of the present invention to provide a hydraulic breaker that prevents a communication between a cylinder loss and a low-pressure passage before the piston hits the chisel, thereby preventing the hitting force from being lowered.

In order to accomplish the above object, the present invention provides a hydraulic breaker comprising: a cylinder constituting a hydraulic breaker body; a back head having a gas chamber at an upper portion of the cylinder; a cylinder bush installed inside the cylinder; A valve for allowing the piston to reciprocate by selectively supplying high-pressure hydraulic fluid to the cylinder chamber and the cylinder chamber, and a valve for reciprocating the cylinder to the high- Pressure orifice and a low-pressure orifice communicating with the low-pressure flow passage, respectively, and the valve inner-diameter chamber is formed by the inner peripheral surface of the inner diameter of the valve and the outer peripheral surface of the cylinder bush. When the piston is in the preparation mode, And serves as a flow resistance means for the hydraulic oil discharged into the low-pressure flow passage. The hydraulic circuit breaker according to claim 1, further comprising: a valve switching pressure generating surface formed in the valve switching chamber in which a high pressure and a low pressure are selectively applied to the valve, When the piston is in the preparation mode, the pressure inside the valve inner-diameter chamber formed in the valve inner-diameter chamber, which is higher than the pressure of the low-pressure passage but lower than the pressure of the high- The valve is formed such that V1> V2 on the hydraulic pressure area, and low pressure and high pressure are selectively applied to the valve switching chamber so that the valve is lowered when the low pressure is formed on the valve switching hydraulic pressure surface V1. , In the valve switching room, oil leakage should be generated only in the clearance between the outer circumferential surface of the valve and the inner circumferential surface of the cylinder. Minimization, and the large-diameter piston peripheral surface is characterized in that accommodated along the inner surface and the inner circumferential surface of cylinder bushing inner diameter of the cylinder bore so as to be movable up and down reciprocally.

In order to achieve the above object, according to the present invention, when the piston is in the preparation mode, the high-pressure hydraulic oil supplied through the oil passage in the cylinder is used only for the lifting of the piston, When the piston is in the operation mode, the high-pressure hydraulic fluid supplied to the cylinder acts on the downward pressure of the piston and only the hydraulic pressure surface of the minimum valve, thereby preventing the piston from falling So that the hitting force is not lowered by preventing the speed from being lowered.

In addition, when the temperature of the hydraulic oil rises and the operating pressure of the hydraulic breaker rises, the leakage path is minimized so that leakage occurs only in the valve outer circumferential surface and the inner circumferential surface of the cylinder in the valve switching chamber when the piston is in the operation mode, The valve is lowered to prevent the cylinder loss from communicating with the low-pressure flow path, so that the hydraulic breaker can be stably operated.

In addition, if the piston is accommodated to reciprocate only along the inner circumferential surface of the inner diameter of the cylinder, the outer circumferential surface of the large diameter portion of the piston only slides with the inner circumference of the cylinder so that the position of the valve must be located above the piston sliding portion. The valve can be positioned at a lower position by accommodating the outer circumferential surface of the large diameter portion of the piston so as to move along the inner circumferential surface of the inner diameter of the cylinder and the inner circumferential surface of the inner diameter of the cylinder bush.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing an internal structure of a hydraulic breaker equipped with a hydraulic breaker valve according to an embodiment of the present invention; FIG.
2 is a view showing a position of a valve when the piston is lifted up in a preparation mode in which the hydraulic breaker of the hydraulic breaker according to the embodiment of the present invention is performed.
3 is a view showing the position of a valve when a piston of a hydraulic breaker according to an embodiment of the present invention is switched from the preparation mode to the operation mode.
4 is a view showing the position of a valve when the piston of the hydraulic breaker is in the working mode in which the descending stroke of the piston is performed in accordance with an embodiment of the present invention.
5 is a sectional view showing a detailed structure of a hydraulic breaker valve according to an embodiment of the present invention;
Fig. 6 is a view showing the operation of the hydraulic breaker valve shown in Fig. 5 when the hydraulic breaker valve is lowered. Fig.
7 is a view showing a state of operation of the hydraulic breaker valve shown in Fig. 5 when lifted. Fig.
8 is a view showing a cross section of a hydraulic breaker to which the prior art is applied;
Fig. 9 is a sectional view showing a valve shape applied to the hydraulic breaker shown in Fig. 8; Fig.
Fig. 10 is a view showing the operation of the hydraulic breaker valve shown in Fig. 9 when the hydraulic breaker valve is lifted. Fig.
Fig. 11 is a view showing the operation of the hydraulic breaker valve shown in Fig. 9 when the hydraulic breaker valve is lowered. Fig.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing the internal structure of a hydraulic breaker equipped with a hydraulic breaker valve according to an embodiment of the present invention. As shown in the figure, the hydraulic breaker 1000 according to the present invention includes a cylinder 100 A piston 120 installed to be vertically movable up and down on an in-cylinder cervical part 110 formed at the center of the cylinder 100 and a piston 120 installed at a lower portion of the cylinder 100 so as to be struck by the piston 120. [ And a gas chamber 910 provided in the upper part of the cylinder 100 and being a sealed space filled with a gas such as nitrogen (N ₂ ). The chuck 810 is inserted into the front head unit 800, And a head 900.

In the cylinder 100, a plurality of oil passages are formed so that high-pressure hydraulic oil discharged from an external hydraulic power source can be introduced into and discharged from the cylinder 100, and a cylinder 120 inserted into the cylinder 100 in such a manner that the piston 120 can be vertically moved up and down. The inner diameter portion 110 is formed.

A cylinder bushing 130 is provided in the in-cylinder portion 110 to reciprocate the piston 120 at a center portion of the cylinder bush 130. A piston 120 is disposed between the outer surface of the cylinder bushing 130 and the in- The valve 200 is provided so as to be movable up and down in order to selectively block or supply the hydraulic oil through a flow path formed in the cylinder 100. [

5 is a cross-sectional view showing a detailed structure of a hydraulic breaker valve according to an embodiment of the present invention. As shown in the figure, the valve 200 is formed in a cylindrical shape, and a cylinder bush 130 A valve inner pressure receiving surface 220 and a valve switching pressure receiving surface 230 are provided on the inner side and the outer side, respectively, and a valve low pressure < RTI ID = 0.0 > The hydraulic breaker according to the embodiment of the present invention is provided with an orifice 240 and a valve high pressure orifice 250. [ The hydraulic breaker 1000 according to the reciprocating motion of the valve 200 sequentially operates the valve 200 in accordance with the above- Will be described, the cylinder 100 is nitrogen in the gas chamber 910 of the back head 900 is provided at the top (N ₂₎ gas, etc. is introduced, the chisel 810 is installed into the front head unit 800 The piston 120 is pressed downward by the pressure in the gas chamber 910 to be positioned at the bottom dead center where the end surface of the piston bottom PL contacts the top surface of the chisel 810, Is located at bottom dead center by self weight.

Pressure hydraulic fluid discharged from an external hydraulic power source flows into the cylinder 400 through the first high-pressure flow passage 310 when the hydraulic fluid of the high pressure discharged from the external hydraulic power source flows into the cylinder 100 through the inlet of the hydraulic breaker 1000, The high pressure hydraulic fluid supplied to the first large diameter portion 122 of the piston 120 acts on the lower pressure side 126 of the first large diameter portion 122 of the piston 120.

The upper and lower surfaces of the valve 200 are respectively located in the valve body 260 and the valve body 280. The valve body 260 and the valve body 280 are respectively connected to the first low- And the third low-pressure flow path 530 so that the low-pressure is always applied.

The valve switching pressure receiving surface 230 of the valve 200 is located in the valve switching chamber 270. The valve switching chamber 270 is connected to the fourth low pressure channel 540, so that a low pressure acts on the valve-switching pressure receiving surface 230 as well.

When the pressure of the cylinder 400 is increased by the high pressure hydraulic fluid supplied to the cylinder 400 through the first high pressure passage 310, When the upward force of the piston 120 is greater than the lower force acting on the end surface of the upper end PU of the piston 910 in the gas chamber 910, The piston 120 begins to rise and the operating fluid of the cylinder overload chamber 410 is transferred to the cylinder bushing orifice 132 and the valve inner diameter chamber 134 and the valve low pressure orifice 240 due to the rise of the piston 120. And is discharged to the second low-pressure passage 520 through the valve low-pressure chamber 290. [

The valve low pressure orifice 240 located between the valve inner diameter chamber 134 and the valve low pressure chamber 290 functions as a flow resistance means for obstructing the flow of the hydraulic fluid and is connected to the valve inner diameter chamber 134 and the valve low pressure chamber 290, so that the pressure in the valve inner diameter chamber 134 becomes higher than the pressure in the valve low pressure chamber 290.

The first low pressure passage 510 and the third low pressure passage 530 and the fourth low pressure passage 540 are connected to the valve chamber 260 and the valve chamber 280, While a pressure higher than that of the second low-pressure passage 520 acts on the valve inner-diameter chamber 134.

Therefore, the lowering force of the valve internal-diameter pressure receiving surface 220 on which the pressure in the valve-inside diameter chamber 134 acts is larger than the lifting force of the valve-switching hydraulic pressure surface 230 on which the pressure in the valve switching chamber 270 acts, The lowered state is maintained.

The piston 120 is then lifted up to the cylinder switching chamber 420 and the piston 120 is lifted up to the piston top PU The gas in the gas chamber 910 is compressed and the gas pressure is increased.

2, when the lower pressure receiving surface 126 of the first large-diameter portion 122 reaches the cylinder conversion chamber 420, the high-pressure hydraulic fluid supplied to the cylinder 400 flows into the conversion chamber flow passage 330 So that a high pressure is formed in the valve switching chamber 270.

Therefore, a high pressure is applied to the valve switching pressure-receiving surface 230 to which the pressure of the valve switching chamber 270 is applied, and a high pressure acting on the first high-pressure flow path 310 is higher than a low pressure acting on the second low- Since the pressure in the valve inner diameter chamber 134 is lower than the hydraulic force acting on the valve inner diameter hydraulic pressure surface 220 because the pressure acting on the valve inner pressure receiving surface 220 acts on the valve inner diameter pressure receiving surface 220 The valve 200 is lifted so that the cylinder overhang 410 formed in the space between the outer circumferential surface of the piston 120 and the inside of the cylinder bushing 130 is communicated through the cylinder bushing orifice 132 and the valve low pressure orifice 240 The second high pressure fluid passage 320 is communicated with the cylinder low pressure chamber 290 through the valve high pressure orifice 250 and the valve inner diameter chamber 134 and the cylinder bushing orifice 132, Pressure passage 320 to the high- The operating oil of the operating fluid is supplied to the cylinder overload chamber 410 through the valve inner circumferential chamber 134 and a high pressure is formed in the valve inner cylinder chamber 134 and the cylinder overload chamber 410.

At this time, the valve inner chamber according to a high pressure is formed in the (134) area of the valve switching pressure-receiving surface 230 and the valve inner pressure-receiving surface 220 of the valve 200 is A _{valve switching pressure-receiving surface>} A _{side valve bore pressure} When a high pressure is simultaneously applied to the valve switching hydraulic pressure surface 230 and the valve inner diameter hydraulic pressure surface 220 due to the relationship between the hydraulic pressure acting on the valve switching hydraulic pressure surface 230 and the hydraulic pressure acting on the valve inner diameter hydraulic pressure surface 220 Since the lift force is large, the rise of the valve 200 is continued.

In addition, the area of the second large diameter part 124, the upper pressure-receiving surface 128 and the first large diameter part 122 is the lower pressure-receiving surface 126 of the piston 120 as the high pressure acts on the cylinder loss 410 A _{lower The} force acting on the piston 120 becomes larger than the upward force by the relationship between the _{hydraulic pressure surface} A and the _{upper hydraulic pressure surface} so that the piston 120 is switched to the working mode in the preparation mode in which the piston- .

At this time, when the piston 120 starts to move downward, the pressing force of the compressed gas in the gas chamber 910 is added to the upper surface of the upper portion PU of the piston 120, The impact force generated by the piston 120 descending to a bottom dead center and striking the top surface of the chisel 810 is transmitted to a solid ground or rock where the tip of the chisel 810 is in contact,

When the piston 120 is completely lowered and is positioned at the bottom dead center, the valve switching chamber 270 is connected to the fourth low-pressure channel 540 through the conversion chamber flow path 330, the cylinder conversion chamber 420, and the cylinder low- The lower pressure acting on the valve inner pressure receiving surface 220 becomes greater than the upward force acting on the valve switching pressure receiving surface 230 so that the valve 200 is lowered do.

As the valve 200 is lowered, the cylinder overload chamber 410 is interlocked with the connection between the cylinder bushing orifice 132 and the valve inner diameter chamber 134 and the second high pressure fluid passage 320 through the valve high pressure orifice 250 At the same time, communicates with the valve low pressure chamber (290), and the piston (120) is switched to the ready mode in which the up stroke is performed in the operation mode in which the down stroke is performed. As the piston 120 moves upwards, a pressure lower than that of the second low-pressure flow path 520 is generated by the valve low-pressure orifice 240, which is flow resistance means, And acts on the valve inner-diameter hydraulic pressure surface 220 so that the valve 200 is lowered to the bottom dead center.

As described above, the operating cycle of the hydraulic breaker 1000 is repeatedly operated in the order of valve descent → piston ascension → valve ascension → piston descent.

The hydraulic breaker 1000 that performs the crushing operation of the object to be crushed by the above-described structure and operation is constructed so that the low-pressure flow path 510, 520, 530, 540 in the operating fluid supplied through the inlet port when the piston 120 is in the preparation mode All of the hydraulic fluid except the operating fluid discharged through the second low pressure passage 520 is used for the upward movement of the piston 120 and the hydraulic oil discharged through the second low pressure flow passage 520 in the cylinder lower chamber 410 is used to hold the valve 200 at the bottom dead center position The lowering speed of the piston 120 is not reduced.

Even when the piston 120 is in the operation mode, the hydraulic fluid is supplied to the valve-switching hydraulic pressure surface 230 and the valve inner-diameter hydraulic pressure surface 220, which are the minimum hydraulic pressure surfaces necessary for the descending stroke of the piston 120 and the behavior of the valve 200 The lowering speed of the piston 120 is not lowered because the operation of the other valve 200 is not used.

That is, it is possible to prevent the working efficiency from being lowered because there is no lowering of the striking water due to the lowering speed of the piston 120 and a lowering of the striking force due to the lowering speed of the piston.

When the operating temperature of the hydraulic oil is raised and the operating pressure of the hydraulic breaker 1000 is increased to increase the amount of leakage of the hydraulic oil, the valve 200 moves up to the valve switching chamber 270 when the operation mode of the piston 120 is performed. The leakage flow path which is inevitably structurally structurally required in the valve 200 is limited to the clearance between the outer circumferential surface of the valve 200 and the inner circumferential surface of the cylinder 100, To prevent the piston 110 from being lowered to a level at which it can not be maintained and to prevent the cylinder liner 410 from communicating with the second low pressure passage 520 before the piston 110 reaches the bottom dead center, .

The outer circumferential surfaces of the first and second large diameter portions 122 and 124 of the piston 110 are opposed to the inner circumferential surface of the inside of the cylinder 100 and the inner circumferential surface of the inside of the cylinder bush 130 The second large diameter portion 124 is located only at the top dead center position of the piston 120 where the lower hydraulic pressure surface 126 of the first large diameter portion 122 reaches the cylinder conversion chamber 420 The cylinder bush 130 and the valve 200 need to be moved in the direction of the back head 900 so that the length of the cylinder 100 is longer than the length of the cylinder 100. [ Which causes the manufacturing cost to increase.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, If the circuit configuration is the same, this can be regarded as the same as the present invention.

1000: Hydraulic Breaker
100: cylinder 110: piston insertion hole
120: piston 122: first large-diameter part
124: second large-diameter portion 126: lower pressure side
128: upper hydraulic surface 130: cylinder bushing
132: cylinder bushing orifice 134: valve inner diameter chamber
200: valve 210: center hole
220: Valve inner diameter Hydraulic side 230: Valve switching hydraulic side
240: valve low pressure orifice 250: valve high pressure orifice
260: valve loss 270: valve switching room
280: valve 310: first high-pressure oil line
320: second high-pressure flow path 330: conversion chamber flow path
400: cylinder 410: cylinder loss
420: cylinder switching chamber 430: cylinder low pressure chamber
510: first low pressure passage 520: second low pressure passage
530: third low pressure passage 540: fourth low pressure passage
800: Front head part 810: Chisel
900: Back head 910: Gas chamber
PU: piston upper part PL: piston lower part

Claims (3)

A cylinder 100 constituting the body of the hydraulic breaker 1000,
A piston 120 installed to be able to move up and down in an in-cylinder diameter portion 110 formed at the center of the cylinder 100,
A chisel 810 inserted into the front head part 800 provided below the cylinder 100 so as to be hit by the piston 120,
A back head 900 provided at an upper portion of the cylinder 100 and having a gas chamber 910 as a closed space filled with high pressure nitrogen gas,
A cylinder bushing 130 mounted on the in-cylinder portion 110 of the cylinder 100 to receive the piston 120 so that the piston can move up and down with the same central axis as the piston 120,
- a cylindrical valve (200) installed between the outer surface of the cylinder bush (130) and the inner cylinder portion (110) so as to be movable in the vertical direction,
The valve (200)
A central hole 210 is formed at the center of the cylindrical bush 130 to receive the cylinder bush 130,
The upper end surface of the valve is positioned at the valve seat 260 and the lower end surface of the valve is positioned at the valve seat 280 so that the valve upper end surface and the lower end surface thereof are always formed with low pressure,
The valve inner diameter hydraulic pressure surface 220 and the valve switching hydraulic pressure surface 230 are formed to have different areas on the inner side of the inner diameter portion of the valve and the outer diameter portion of the valve, When the pressure acting on the valve inner diameter pressure receiving surface 220 is greater than the pressure acting on the valve switching pressure receiving surface 230, the upward stroke of the piston When the pressure acting on the valve switching pressure receiving surface 230 is greater than the pressure acting on the valve inner pressure receiving surface 220,
Wherein at least one valve low-pressure orifice (240) and a valve high-pressure orifice (250) respectively penetrating the valve outer-diameter portion and the inner-diameter portion are formed.
3. The apparatus of claim 1, wherein the valve low pressure orifice (240)
The cylinder liner 410 is formed to be in communication with the second low pressure passage 520 and to function as a flow resistance means for discharging the working oil when the operating oil in the cylinder liner 410 is discharged into the second low pressure passage 520 Hydraulic breaker.
2. The piston according to claim 1,
Is housed so as to move relative to the inner circumferential surface of the in-cylinder portion and the inner circumferential surface of the cylinder bush at the time of the rising stroke and the descending stroke.

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