KR101726843B1 - Working Fluid Filling Apparatus for preventing nature descent - Google Patents

Working Fluid Filling Apparatus for preventing nature descent Download PDF

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Publication number
KR101726843B1
KR101726843B1 KR1020150062268A KR20150062268A KR101726843B1 KR 101726843 B1 KR101726843 B1 KR 101726843B1 KR 1020150062268 A KR1020150062268 A KR 1020150062268A KR 20150062268 A KR20150062268 A KR 20150062268A KR 101726843 B1 KR101726843 B1 KR 101726843B1
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KR
South Korea
Prior art keywords
cylinder
operating
hydraulic
valve
boom
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KR1020150062268A
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Korean (ko)
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KR20160130117A (en
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방철희
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디와이 주식회사
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
    • B66C23/18—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes
    • B66C23/36—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes
    • B66C23/42—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes with jibs of adjustable configuration, e.g. foldable
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C15/00—Safety gear
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C2700/00—Cranes
    • B66C2700/03—Cranes with arms or jibs; Multiple cranes
    • B66C2700/0321—Travelling cranes
    • B66C2700/0357—Cranes on road or off-road vehicles, on trailers or towed vehicles; Cranes on wheels or crane-trucks
    • B66C2700/0364—Cranes on road or off-road vehicles, on trailers or towed vehicles; Cranes on wheels or crane-trucks with a slewing arm

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Jib Cranes (AREA)
  • Fluid-Pressure Circuits (AREA)

Abstract

The present invention relates to an operating oil filling apparatus for preventing a natural descent of a crane, the operating filling apparatus comprising: an operating cylinder operated by operating oil; A direction switching valve that opens the inlet port and the first supply port by the first orifice in the neutral mode and switches the direction of the operating cylinder; And a first counterbalance valve provided on a first supply line connecting the first supply port and the piston rear end side of the operating cylinder and having a first check valve for allowing the flow of the hydraulic fluid to the rear end side of the piston, Target portion; And a hydraulic device operable to operate using the hydraulic oil, wherein when a natural descent occurs in which the rod of the operating cylinder retreats when the directional control valve is neutral, the hydraulic oil is pressurized by the pressure applied to the hydraulic device, Through the orifice to the rear end side of the piston of the operating cylinder.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a working fluid filling apparatus for preventing descent of a crane,

[0001] The present invention relates to a hydraulic oil filling apparatus for preventing a natural fall of a crane, and more particularly, to a hydraulic oil filling apparatus for preventing the hydraulic pump from operating when the directional switching valve for switching the direction of the operating cylinder in a state in which the tip of the boom assembly of the crane is up- The rod of the operating cylinder suddenly rises when the directional switching valve for switching the direction of the operating cylinder is in the neutral state while preventing the natural descent of the rod of the cylinder from retracting and the tip of the boom assembly of the crane is diagonally downward And an operating oil filling device for filling the operating cylinder with operating oil to prevent the operating cylinder from being projected.

The crane includes a boom assembly composed of a multi-stage boom, and the boom assembly is configured to be pulled or drawn so that its length is elongated or contracted. Figure 1 (PN101253) shows a typical truck crane. The truck crane is mounted on the truck with the above crane.

As shown in Fig. 1, the truck crane 10 includes a truck 1 on which a driver is boarding, and a boom assembly (a multi-stage boom-inserted assembly) 2 which is coupled to the truck 1. The boom assembly 2 is stretchable or retractable as an assembly in which a plurality of booms are superimposed and joined together, and the boom assembly 2 is lifted or lowered by the relief cylinders 3. The boom assembly 2 is provided with a boom cylinder (not shown) for pulling out and drawing a plurality of booms. The boom assembly 2 is coupled to a column 4 which is coupled to the truck 1. A pulley 5 is mounted on the boom assembly 2 and the hook 7 is fixed to the end of the wire rope 6 to lift or move the load body having a constant load. The crane has a winding (8) that operates to pull or unwind the wire (6).

The boom cylinder, relief cylinder (3), and winding device (8) are operated by operating oil. Particularly, even when the boom cylinder and the relief cylinder 3 are in the neutral mode for switching the direction of the boom cylinder and the relief cylinder 3, there is a natural descent phenomenon in which the rod of the cylinder retreats due to shrinkage of the hydraulic oil or the like do.

2 schematically shows a hydraulic circuit in a conventional crane. As shown in Fig. 2, the operating oil is stored in the tank 11 and supplied by the pump 12, and the first operating cylinder 21 and the second operating cylinder 31 are operated by the operating oil.

More specifically, the first operating portion 20 includes a first operating cylinder 21, a first counterbalance valve 22, and a first direction switching valve 23, and the second operating portion 30 includes A second counter cylinder valve 31, a second counterbalance valve 32, and a second directional control valve 33, as shown in Fig. The first actuating cylinder 21 may be a boom cylinder, and the second actuating cylinder 31 may be a relief cylinder.

2 shows the first and second actuating cylinders 21 and 31 in a neutral state. As shown in FIG. 2, the directional switching valve employed in the conventional crane adopts a system in which the inlet port P and the supply ports A and B are completely shut off in the neutral state. That is, in the neutral state, the hydraulic fluid supplied from the inlet port P to the supply ports A and B is supplied to the first operation cylinder 21 or the second operation cylinder 31 by the hydraulic fluid supplied in the neutral state, .

However, even when the first and second actuating cylinders 21 and 31 are in the neutral state, the volume of the working oil shrinks due to the cooling of the working oil and the like, and the rod of the cylinder retreats. For example, the boom assembly, which is held in a tensioned state by a boom cylinder for a certain length, can cause the boom assembly to shrink when suddenly the rod retracts due to the natural fall of the boom cylinder.

Likewise, the boom assembly is maintained at a certain angle by the relief cylinder, and when the rod of the relief cylinder suddenly retreats due to the natural descent, the boom assembly erected at a certain angle may fall down and cause an accident. That is, the phenomenon of the natural descent of the cylinder makes the operation of the crane difficult, and in some cases, unexpected accidents may occur. Therefore, there is a demand for a device capable of properly preventing such a natural falling phenomenon.

Korean Patent Publication No. 2006-0068868

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a boom assembly for a crane, in which a boom assembly of a crane is installed in a neutral state, And the rod of the operating cylinder suddenly protrudes when the direction switching valve for switching the direction of the operating cylinder is in a neutral state in a state in which the tip of the boom assembly of the crane is diagonally downward And to provide a working oil filling device that fills working cylinders with working oil.

According to an aspect of the present invention, there is provided an operating oil filling apparatus for preventing a natural descent of a crane, comprising: a tank (230) and a working oil supplied through a pump (240) provided in the tank An actuating cylinder 110; In the neutral mode, the inlet port 121 and the first supply port 122, which are connected to the tank 230 through the inflow line 250, are opened by the first orifice 124, A direction switching valve (120) for switching the direction; A first supply line 126 connecting the first supply port 122 and the rear end of the piston 113 of the actuating cylinder 110 and configured to allow the flow of the hydraulic fluid to the rear end side of the piston 113; A first counterbalance valve (130) having a first check valve (131); And a hydraulic device 140 operated by using the hydraulic oil branched and supplied from the inlet line 250. When the directional valve 120 is neutralized, The hydraulic oil is filled into the rear end side of the piston 113 of the operating cylinder 110 through the first orifice 124 by the pressure applied to the hydraulic device 140. [ .

The operating cylinder is preferably a boom cylinder for extending and contracting the boom assembly of a crane comprising a multi-stage boom, or a lowering cylinder for lifting the boom assembly.

In addition, it is preferable that at least one object to be filled is provided.

The directional switching valve is provided in a second supply line that connects the second supply port and the rod side of the front end of the piston of the operating cylinder in the neutral mode when the inlet port and the second supply port are opened by the second orifice And a second counterbalance valve having a second check valve for allowing the flow of the hydraulic fluid to the rod side.

According to another aspect of the present invention, there is provided a hydraulic oil filling apparatus for preventing a natural lowering of a crane, the hydraulic oil filling apparatus comprising a tank (230) and a hydraulic oil supplied through a pump (240) An actuating cylinder 110; In the neutral mode, the inlet port 121 and the second supply port 123, which are connected to the tank 230 through the inflow line 250, are opened by the second orifice 125, A direction switching valve (120) for switching the direction; And a second supply line 127 connecting the second supply port 123 and the rod 114 of the front end of the piston 113 of the actuating cylinder 110, And a second counterbalance valve (150) having a second check valve (151) for allowing the second check valve (151) to permit the first check valve (151). And a hydraulic device 140 operated by using the hydraulic oil branched and supplied from the inlet line 250. When the directional valve 120 is neutralized, The hydraulic oil is filled to the rod 114 side of the operating cylinder 110 through the second orifice 125 by the pressure applied to the hydraulic device 140. [

The operating cylinder is preferably a boom cylinder for extending and contracting the boom assembly of a crane comprising a multi-stage boom.

The hydraulic oil filling device for preventing a natural lowering of a crane according to an aspect of the present invention is characterized in that when the directional switching valve for switching the direction of the operating cylinder in the state where the tip of the boom assembly of the crane is obliquely upwardly upward is in the neutral state , The working cylinder is filled with the operating oil by using the pressure applied to the hydraulic device, thereby preventing the natural descent in which the rod of the operating cylinder retreats.

In addition, according to another aspect of the present invention, there is provided an operating oil filling apparatus for preventing a natural fall of a crane, wherein a direction change valve for changing the direction of the operating cylinder in a state in which the tip of the boom assembly of the crane is diagonally downward, It is possible to prevent the rod of the operating cylinder from suddenly protruding by filling the operating cylinder with the working oil by using the pressure applied to the hydraulic device.

1 is a schematic view of a conventional truck crane,
Figure 2 is a schematic diagram of the hydraulic circuit employed in Figure 1,
3 shows a hydraulic circuit according to an embodiment of the present invention,
4 shows a hydraulic circuit according to another embodiment of the present invention,
5 is a view showing a hydraulic circuit according to another embodiment of the present invention,
FIG. 6 is a schematic view of a crane boom assembly when FIGS. 3 to 5 are applied; FIG.
7 shows a hydraulic circuit according to another embodiment of the present invention,
8 is a view showing a hydraulic circuit according to another embodiment of the present invention;
Figure 9 is a schematic view of a crane boom assembly when Figures 7 and 8 are applied.

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

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. As used herein, "comprises" and / or "comprising " do not exclude the presence or addition of one or more other members other than the recited member.

Unless defined otherwise, all terms (including technical and scientific terms) used herein may be used in a sense commonly understood by one of ordinary skill in the art to which this invention belongs.

FIG. 3 is a view showing a hydraulic circuit according to an embodiment of the present invention, FIG. 4 is a view showing a hydraulic circuit according to another embodiment of the present invention, and FIG. 5 is a schematic view of a hydraulic circuit according to another embodiment of the present invention Fig. FIG. 6 is a schematic view of a crane boom assembly when FIGS. 3 to 5 are applied. FIG.

Referring to FIG. 3, an oil filling apparatus for preventing a natural descent of a crane according to an embodiment of the present invention includes a filling target part 100 and a hydraulic device 140.

The charging target portion 100 includes a working cylinder 110, a directional control valve 120, and a first counterbalance valve 130, which is a part to be filled with the hydraulic fluid due to a natural descent.

The operating cylinder 110 is operated by operating oil. The hydraulic oil is stored in the tank 230 and supplied by the pump 240. In this embodiment, the working cylinder 110 means a cylinder which is operated by operating oil and in which a natural descent may occur.

In the crane, a boom cylinder for extending and retracting the multi-stage booms constituting the boom assembly 210, or a relief cylinder for raising the boom assembly 210 corresponds to the operation cylinder 110. As shown in Fig. 3, the actuating cylinder 110 includes a cylinder body 111 and a rod portion 112. The rod portion 112 includes a piston 113 and a rod 114. Fig. 3 shows a case where there is one operating cylinder, and the operating cylinder 110 may be the boom cylinder or the undersurface cylinder.

The directional valve 120 is provided to adjust the direction of the operating oil supplied to the operating cylinder 110 so as to project or immobilize the rod 114 of the operating cylinder 110 from the cylinder body 111 . According to the present embodiment, the directional valve 120 is opened by the first orifice 124 in the neutral mode when the inlet port 121 and the first supply port 122 are opened.

The first orifice 124 is formed with a flow passage for the hydraulic fluid to flow finely. In the neutral mode, the inlet port 121 and the first supply port 122 are opened by the first orifice 124, When operating cylinder 110 is in the neutral mode, hydraulic oil can be supplied to the operating cylinder 110 side through the first orifice 124 by a pressure acting on another hydraulic device 140 described later it means.

The first counterbalance valve 130 is provided on a first supply line 126 connecting the first supply port 122 and the rear end side of the piston 113 of the actuating cylinder 110. The first counterbalance valve 130 includes a first check valve 131 for allowing the flow of the hydraulic fluid to the rear end side of the piston 113.

The first check valve 131 interrupts the flow of hydraulic fluid from the rear end side of the piston 113 toward the direction switching valve 120 and the hydraulic fluid from the direction switching valve 120 side to the rear end side of the piston 113 Operating fluid can be supplied. The first counterbalance valve 130 interrupts the flow of hydraulic fluid from the rear end side of the piston 113 toward the direction switching valve 120 when the operating cylinder 110 is in the neutral mode, Which is provided to stably maintain the pressure of the operating oil of the engine.

The hydraulic device 140 is operated by using the hydraulic oil. The hydraulic oil is supplied from the tank 230 by the pump 240. The hydraulic oil supplied to the hydraulic device 140 branches off from the hydraulic oil inlet line 250 connecting the inlet port 121 of the operating cylinder 110 from the tank 230 to the hydraulic device 140, The pressure of the supplied operating oil also acts on the inflow line 250.

The operation of the embodiment according to the present invention will be described in detail with reference to FIGS. 3 and 6. FIG.

6 is a schematic view of a crane boom assembly 210 to which an oil filling apparatus according to an embodiment of the present invention is applied. As shown in FIG. 6, the boom assembly 210 has its tip positioned higher than the column. That is, the boom assembly 210 is operated in a state in which the leading end of the boom assembly 210 stands up in an upward direction.

The state of the boom assembly 210 is achieved by the following operation. The operating oil stored in the tank 230 is supplied to the piston 113 of the operating cylinder 110 via the directional control valve 120 and the first check valve 131 of the first counterbalance valve 130 by the pump 240, And is supplied to the rear end side. When the rod 114 of the working cylinder 110 is protruded as much as desired, the directional control valve 120 maintains the neutral position.

In this embodiment, when the operating cylinder 110 is a boom cylinder, it means that the boom cylinder 210 is kept in a neutral state after the multi-stage boom is drawn out to a predetermined length in a state where the boom assembly 210 is raised. Or when the operating cylinder 110 is a relief cylinder, the relief cylinder remains in a neutral state after the rod of the relief cylinder has protruded to erect the boom assembly 210. At this time, the supply of the operating fluid to the working cylinder 110 is stopped, and the inlet port 121 and the first supply port 122 are kept open by the first orifice 124.

The crane is provided with a hydraulic device (140) which operates by hydraulic pressure in addition to the boom cylinder. For example, this corresponds to a winch constituting a crane. When the pump 240 is operated to operate the hydraulic device 140 and pressure is applied to supply the hydraulic fluid, the pressure acts on the inflow line 250 side connecting the tank 230 and the inflow port 121 do.

The boom cylinder for operating the multi-stage boom of the boom assembly 210, and the relief cylinder for lifting the boom assembly 210 itself, even when the neutral cylinder is in the neutral state, the hydraulic oil is contracted and the rod 114 of the cylinder suddenly retreats A falling phenomenon may occur.

3, when the operating oil on the rear end side of the piston 113 of the operating cylinder 110 is contracted and the pressure is lowered, the hydraulic oil is supplied to the first orifice 124 and is filled to the rear end side of the piston 113 through the first check valve 131 of the first counterbalance valve 130. Accordingly, the working oil is replenished to the rear end side of the piston 113, thereby preventing natural descent due to the contraction of the operating oil.

FIG. 4 illustrates a hydraulic oil filling apparatus for preventing a natural descent of a crane according to another embodiment of the present invention. According to the present embodiment, at least one or more objects to be filled 100 may be provided. In this embodiment, the configuration other than the configuration in which there are a plurality of charging target portions 100 is the same as that in the embodiment of Fig. 3, and thus a detailed description thereof will be omitted.

More specifically, FIG. 4 shows a case where there are two filling target parts 100. For example, a filling apparatus according to the present invention can be employed in a boom cylinder and a relief cylinder of a crane. Of course, the object to be filled 100 is not limited to the above two, since it depends on the number of the actuating cylinders 110 in which the natural fall may occur.

When the operating cylinder is a boom cylinder and a relief cylinder, the angle of the boom assembly 210 is adjusted by the relief cylinder to maintain the raised state of the tip of the boom assembly 210 upward, as shown in FIG. Is maintained. The underside cylinder and the boom cylinder remain neutral when the rod 114 of the underside cylinder is raised so as to stand at a constant angle and the rod 114 of the boom cylinder is projected to extend the boom assembly 210 as desired. Since the process up to maintaining the neutral state is similar to that described above, a detailed description thereof will be omitted.

As shown in Fig. 4, the pressure applied to the hydraulic device 140 such as a winch acts on the plurality of objects 100 to be filled. That is, in this embodiment, the boom cylinder and the relief cylinder are operated to fill the operating oil, respectively. The operation in which the pressure applied to the hydraulic device 140 acts on both the boom cylinder and the relief cylinder is the same as the operation according to the embodiment of FIG.

FIG. 5 illustrates a hydraulic oil filling apparatus for preventing a natural descent of a crane according to another embodiment of the present invention. The embodiment of FIG. 5 includes a plurality of charging target portions 100 as in the embodiment of FIG. According to the embodiment of FIG. 5, the configuration of a plurality of filling target parts 100 is partially the same as the embodiment of FIG. 4, but the configuration of the other filling target parts 100 is different from the embodiment of FIG. Hereinafter, the filling target part 100 having a configuration different from that of FIG. 4 will be described in detail.

5, in the neutral mode, the directional valve 120 is opened by the second orifice 125 in the inlet port 121 and the second supply port 123, as shown in FIG. It is the same that the inlet port 121 and the first feed pawl 122 are open to the first orifice 124. And a second counterbalance valve 150 is provided on a second supply line 127 connecting the second supply port 123 and the rod side of the actuating cylinder 110.

The second counterbalance valve 150 includes a second check valve 151 for allowing the flow of the hydraulic fluid to the rod 111 side. In other words, according to the embodiment of FIG. 5, at least one of the plurality of filling target parts 100 is connected to the inflow port 121, the first supply port 121 and the second supply port 121 in the neutral mode, (122) are opened by the first orifice (124) and the second orifice (125), respectively.

The embodiment of FIG. 5 is also applied when the boom assembly of the crane is arranged as shown in FIG. When the directional valve 120 is in the neutral mode and the operating fluid of the actuating cylinder 110 contracts and the pressure drops, the pressure to actuate the other hydraulic device acts on the hydraulic line 250 so that the first and second orifices 124 and 125 ) Is filled with hydraulic oil. The operation cylinder 110 having the first and second orifices 124 and 125 in the neutral state is filled with the operating oil by the same action as that of the operating cylinder 110 employing only the first orifice 124, 110).

FIGS. 7 and 8 are views showing a hydraulic circuit according to another embodiment of the present invention, and FIG. 9 is a schematic view of a crane boom assembly when FIGS. 7 and 8 are applied.

According to the embodiment of FIG. 7, the working oil filling apparatus according to the present embodiment includes the filling target portion 100 and the hydraulic device 140, as in the embodiment of FIG. 7, the operating oil is cooled and contracted on the rod 114 side of the front end of the piston 113 of the operating cylinder 110 in a state where the boom assembly 210 is disposed as shown in FIG. 9, The distal end of the rod 114 is prevented from suddenly protruding.

Specifically, the object to be filled 100 includes an operation cylinder 110, a directional control valve 120, and a second counterbalance valve 150.

The operating cylinder 110 is operated by operating oil. According to the present embodiment, the operating cylinder 110 operates in the same manner as the embodiment of FIG. 9, the operating cylinder 110 is cooled by the cooling fluid supplied to the rod 114 at the front end of the piston 113, and the cylinder 114, which is capable of spontaneously falling, .

Therefore, according to the present embodiment, the operating cylinder 110 may be a boom cylinder that extends and contracts the boom assembly 210 of a crane comprising a multi-stage boom. In the present embodiment, the operating cylinder includes a cylinder body 111 and a rod portion 112, as shown in Fig. The rod portion 112 includes a piston 113 and a rod 114.

The directional valve 120 is provided to adjust the direction of the operating oil supplied to the operating cylinder 110 so as to project or immobilize the rod 114 of the operating cylinder 110 from the cylinder body 111 . According to the present embodiment, the directional valve 120 is opened by the second orifice 125 in the neutral mode when the inlet port 121 and the second supply port 123 are opened.

The second orifice 125 has a flow path such that the hydraulic fluid flows finely like the first orifice 124. In the neutral mode, the inflow port 121 and the second supply port 123 are connected to the second orifice Means that the hydraulic fluid is discharged from the hydraulic cylinder 140 through the second orifice 125 by the pressure acting on the other hydraulic device 140 when the operating cylinder 110 is in the neutral mode, 110). ≪ / RTI >

The second counterbalance valve 150 is provided on a second supply line 127 connecting the second supply port 123 and the rod 114 side of the piston 113 of the operating cylinder 110 do. The second counterbalance valve 150 includes a second check valve 151 allowing the flow of the hydraulic fluid to the rod 114 side. The second check valve 151 interrupts the flow of hydraulic fluid from the rod 114 side to the direction switching valve 120 side and the hydraulic oil can be supplied to the rod 114 side.

The second counterbalance valve 150 is closed when the operation cylinder 110 is in the neutral mode and the flow of hydraulic fluid from the rod 114 side to the directional valve 120 side is blocked, 114), and employs a well-known structure.

The hydraulic device 140 is operated by using the hydraulic oil. The hydraulic oil is supplied from the tank 230 by the pump 240. The hydraulic oil supplied to the hydraulic device 140 branches off from the hydraulic oil inlet line 250 connecting the inlet port 121 of the operating cylinder 110 from the tank 230 to the hydraulic device 140, The pressure of the supplied operating oil also acts on the inflow line 250.

The hydraulic device 140 is a device that operates using the hydraulic oil as in the embodiment of FIG. 3, for example, a winch or the like. The hydraulic device 140 receives the operating fluid from the tank 230 by the pump 240. The hydraulic oil supplied to the hydraulic device 140 branches off from the hydraulic oil inlet line 250 connecting the inlet port 121 of the operating cylinder 110 from the tank 230 to the hydraulic device 140, The pressure of the supplied operating oil also acts on the inflow line 250.

The operation of another embodiment according to the present invention will be described in detail with reference to FIGS. 7 and 9. FIG.

As shown in Fig. 9, the boom assembly 210 is inclined so that its tip end faces downward. In other words, as compared with the case where the boom assembly 210 is horizontally disposed, the tip of the boom assembly 210 is tilted downward, so that the boom assembly 210 is positioned and operated in a so-called minus (-) direction.

The state of such a boom assembly 210 is operated by the undulating cylinder so that the tip of the boom assembly 210 faces downward as compared to Fig. 3, and the multi-stage boom of the boom assembly 210 is drawn out as long as necessary. When the rod 114 of the operating cylinder 110 (boom cylinder) is protruded as much as desired, the directional control valve 120 maintains the neutral position. At this time, the supply of the working oil to the operating cylinder 110 is stopped, and the inlet port 121 and the second supply port 123 are kept open by the second orifice 125.

In this state, when pressure is applied in the process of supplying the hydraulic oil to the hydraulic device 140, for example, the hydraulic pump 140 operating the hydraulically operated hydraulic pump, for operating the winch constituting the crane, (250) connecting the inlet port (230) and the inlet port (121).

As described above, even when the boom cylinder for operating the multi-stage boom of the boom assembly 210 is in the neutral state, the operating oil is cooled and contracted, and in the state as shown in Fig. 9, the rod 114 of the boom cylinder suddenly protrudes A falling phenomenon may occur.

7 and 9, when the working oil on the rod 114 side of the operating cylinder 110 is contracted and the pressure is lowered, the hydraulic oil is supplied to the hydraulic cylinder 140 by the pressure of the hydraulic oil for operating the hydraulic machine 140, Through the orifice 125 and through the second check valve 151 of the second counterbalance valve 150 to the rod 114 side. Accordingly, the working oil is replenished to the rod 114 side, thereby preventing natural descent due to the contraction of the working oil.

7 and 9, the boom cylinder, which is the actuating cylinder 110, may be opened by the second orifice 125 to prevent the first and second supply ports 121, The relief cylinder capable of involving a natural descent phenomenon as another working cylinder 110 is connected to the directional control valve 120 of the relief cylinder by means of the inlet port 121 and the first supply port 122) are simultaneously opened to the first orifice 124 (see FIG. 8), so that it is possible to prevent the boom cylinder and the undulating cylinder from being naturally lowered.

As described above, in the operating oil filling apparatus for preventing the natural descent of the crane according to the present invention, in the operating cylinder 110 that can cause the natural descent, the inlet port and the supply port are opened by the orifice in the neutral mode of the directional control valve When the operating oil supplied to the operating cylinder is cooled and shrunk and the pressure is reduced, the operating cylinder is filled with the operating oil by using the operating pressure of other hydraulic devices constituting the crane, thereby preventing the natural descent. Since the filling process is automatically performed when the other hydraulic devices constituting the crane are operated, the driver can perform the operation stably while eliminating the concern of natural descent.

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, and many modifications may be made without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100 ... filling target part 110 ... working cylinder
111 ... cylinder body 112 ... rod portion
113 ... piston 114 ... rod
120 ... directional control valve 121 ... inlet port
122 ... first supply port 123 ... second supply port
124 ... first orifice 125 ... second orifice
126 ... first supply line 127 ... second supply line
130 ... first counterbalance valve 131 ... first check valve
140 ... hydraulic device 150 ... second counterbalance valve
151 ... second check valve 210 ... boom assembly
220 ... column 230 ... tank
240 ... pump 250 ... inflow line

Claims (6)

An operating cylinder 110 operated by a working fluid supplied through a tank 230 and a pump 240 provided in the tank 230; In the neutral mode, the inlet port 121 and the first supply port 122, which are connected to the tank 230 through the inflow line 250, are opened by the first orifice 124, A direction switching valve (120) for switching the direction; A first supply line 126 connecting the first supply port 122 and the rear end of the piston 113 of the actuating cylinder 110 and configured to allow the flow of the hydraulic fluid to the rear end side of the piston 113; A first counterbalance valve (130) having a first check valve (131); And
And a hydraulic device (140) operating using the hydraulic oil branched and supplied from the inflow line (250)
When the rod 114 of the actuating cylinder 110 retreats when the directional control valve 120 is neutralized, the pressure applied to the hydraulic device 140 causes the hydraulic fluid to flow to the first orifice 124 ) To the rear end of the piston (113) of the operating cylinder (110). The method according to claim 1,
The operating cylinder 110 is a boom cylinder for extending and contracting the boom assembly 210 of a crane made up of a multi-stage boom or an undulating cylinder for lifting the boom assembly 210. An operating oil Filling device. The method according to claim 1,
Wherein the at least one filling target part (100) is provided. The method according to claim 1,
In the neutral mode, the directional valve 120 opens the inlet port 121 and the second supply port 123 by the second orifice 125,
And a second supply line 127 connecting the second supply port 123 and the rod 114 of the front end of the piston 113 of the actuating cylinder 110, And a second counterbalance valve (150) having a second check valve (151) for permitting the second check valve (151). An operating cylinder 110 operated by a working fluid supplied through a tank 230 and a pump 240 provided in the tank 230; In the neutral mode, the inlet port 121 and the second supply port 123, which are connected to the tank 230 through the inflow line 250, are opened by the second orifice 125, A direction switching valve (120) for switching the direction; And a second supply line 127 connecting the second supply port 123 and the rod 114 of the front end of the piston 113 of the actuating cylinder 110, And a second counterbalance valve (150) having a second check valve (151) for allowing the second check valve (151) to permit the first check valve (151). And
And a hydraulic device (140) operating using the hydraulic oil branched and supplied from the inflow line (250)
When the rod 114 of the actuating cylinder 110 protrudes when the directional control valve 120 is neutralized, the hydraulic oil is supplied to the hydraulic actuator 140 via the second orifice 125, Is filled to the rod (114) side of the cylinder (110). 6. The method of claim 5,
Wherein the operating cylinder (110) is a boom cylinder for extending and contracting the boom assembly (210) of a crane comprising a multi-stage boom.
KR1020150062268A 2015-05-01 2015-05-01 Working Fluid Filling Apparatus for preventing nature descent KR101726843B1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000335888A (en) 1999-05-26 2000-12-05 Komatsu Ltd Counterbalance valve
JP2003294009A (en) 2002-03-29 2003-10-15 Kobelco Contstruction Machinery Ltd Hydraulic cylinder circuit
JP2007084331A (en) * 2005-09-26 2007-04-05 Kato Works Co Ltd Boom derricking hydraulic circuit

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0814208A (en) * 1994-06-29 1996-01-16 Sumitomo Constr Mach Co Ltd Natural shrinkage preventing device for boom extension derricking cylinder
KR19990069369A (en) * 1998-02-07 1999-09-06 토니헬 Boom Length Keeper and Method
KR20060068868A (en) 2004-12-17 2006-06-21 현대중공업 주식회사 More stable and controllable holding valve

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000335888A (en) 1999-05-26 2000-12-05 Komatsu Ltd Counterbalance valve
JP2003294009A (en) 2002-03-29 2003-10-15 Kobelco Contstruction Machinery Ltd Hydraulic cylinder circuit
JP2007084331A (en) * 2005-09-26 2007-04-05 Kato Works Co Ltd Boom derricking hydraulic circuit

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