KR101040152B1 - Hydraulic Jack With Screw Type Retractor - Google Patents

Abstract

The present invention is a hydraulic jack provided with a screw-type locking device that is not changed in the fixed position even under the environment that the guide shaft of the cylinder and the nut of the rod is screwed and the locking device is added to keep the load supporting state for a long time by using the locking device As for

A cylinder 10 having hydraulic ports 11 and 12 installed at upper and lower ends thereof, respectively; A rod 15 which is lifted up and down in the cylinder 10 in accordance with the supply of hydraulic oil; A footrest 18 connected to the lower end of the rod 15; A guide shaft 14 rotatably installed in the cylinder 10 and having a thread formed on an outer circumferential surface thereof; A nut 16 installed at an upper end of the rod 15 and screwed to the guide shaft 14 to rotate the guide shaft 14 as the rod 15 moves up and down; A rotating body 13 installed on the guide shaft 14 and having a thread 13 'formed on an outer circumferential surface thereof; It is installed in the cylinder 10 and the locking device 20 for restraining or releasing the rotating body 13 in accordance with the supply of the hydraulic oil; characterized in that it comprises a.

Therefore, the guide shaft and the nut are screwed together, and the locking device restrains the rotating body to fix the position of the rod, so that the position can be fixed for a long time without using the piston position sensing means or the control means.

Hydraulic Jack, Rod, Locking Device, Guide Shaft, Rotating Body, Nut, Hydraulic Port, Universal Joint

Description

Hydraulic Jack With Screw Type Retractor}

The present invention relates to a hydraulic jack that is a device for temporarily lifting heavy objects by using hydraulic pressure, and in particular, a load supporting state is used for a long time by using a locking device that restrains the screw shaft and the guide shaft of the guide shaft installed in the cylinder and the nut. The present invention relates to a hydraulic jack provided with a screw-type locking device such that there is no change in the fixed position even in a maintained environment.

A hydraulic jack is a type of jack that temporarily lifts heavy items. The hydraulic jack supplies hydraulic oil supplied from the hydraulic device to the upper side or the lower side of the cylinder so that the rod inside the cylinder moves up and down to expand or contract. Means.

As shown in FIG. 1, a conventional hydraulic jack includes a cylinder having a piston 60 mounted therein so as to be liftable therein and having hydraulic ports 51 and 52 provided at upper and lower sides of the piston 60, respectively. 50 and a scaffold 70 provided at an end of the rod 65 of the piston 60.

Here, in order to explain the operation of the hydraulic ports 51 and 52 in detail, those located on the upper side of the piston 60 for convenience 'cylinder side hydraulic port 51', the lower side of the piston 60 It is located in the 'rod side hydraulic port 52'.

In the conventional hydraulic jack configured as described above, the hydraulic jack is expanded or contracted by supplying hydraulic oil to the cylinder-side hydraulic port or the rod-side hydraulic port to elevate the piston.

When the hydraulic oil is supplied to the cylinder-side hydraulic port 51 by using the hydraulic device, the piston 60 is lowered by the hydraulic pressure, so that the scaffold 70 installed on the rod 65 of the piston 60 has a cylinder ( The hydraulic jack is expanded by moving in the direction away from 50). At this time, the hydraulic oil in the lower portion of the piston 60 is discharged through the rod-side hydraulic port (52).

When the hydraulic oil 52 is supplied to the rod side hydraulic port by using a hydraulic device, the piston 60 is lifted by hydraulic pressure, and the scaffold 70 installed on the rod of the piston 60 is in a cylinder direction. The hydraulic jack is reduced by moving to. At this time, it is natural that the hydraulic oil in the upper portion of the piston 60 is discharged through the cylinder-side hydraulic port (51).

The hydraulic jack of the above structure is excellent in load bearing capacity and easy to adjust, so it is widely used in various fields such as ground works, civil works, and automobiles.However, when the hydraulic jack is operated for a long time, it is fixed due to minute leakage on the valve and hydraulic circuit. It is difficult to create sufficient pressure to maintain position.

In other words, in order to maintain the fixed position of the hydraulic jack, the hydraulic pressure in the cylinder must be kept constant, but the hydraulic pressure in the cylinder may be changed due to leakage or the like, and the position of the piston may be changed. Therefore, it is necessary to precisely control the hydraulic pressure in the cylinder by driving the hydraulic device while continuously detecting the position of the piston in the cylinder, or to block the hydraulic change by adopting a high precision seal. A hydraulic jack having such a piston position measuring device is disclosed in Korean Patent Publication No. 1992-0004529.

However, the conventional hydraulic jack is to precisely control the hydraulic pressure using a device for detecting the hydraulic change in the cylinder or to fix the position of the piston using a high-precision seal, the structure is complicated, the production cost is increased, of course, There is a problem that costs a lot for maintaining the reliability.

The present invention has been made to solve the above-mentioned conventional problems, even if there is a difficulty in forming the hydraulic pressure in the hydraulic jack using a locking device installed therein can be fixed so as not to change the fixed position of course to maintain the fixed position It is an object of the present invention to provide a hydraulic jack equipped with a threaded lock that does not require a separate accessory.

The present invention for achieving the above object, and the hydraulic port is installed at the top and bottom, respectively; A rod which is lifted up and down in the cylinder according to the supply of the hydraulic oil through the hydraulic port; A scaffold connected to the lower end of the rod; A guide shaft rotatably installed in the cylinder and having a thread formed on an outer circumferential surface thereof; A nut installed at an upper end of the rod and screwed to the guide shaft to rotate the guide shaft as the rod moves up and down; A rotating body installed at an upper end of the guide shaft and having a screw thread formed on an outer circumferential surface thereof; And a locking device installed inside the cylinder and restraining or releasing the rotating body in accordance with the supply of hydraulic oil.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, by forming a ball screw structure provided with a plurality of balls between the guide shaft and the nut to convert the vertical movement of the rod into a rotational movement of the guide shaft. It is done.

In addition, the hydraulic jack with a threaded locking device of the present invention is characterized in that the universal joint is provided to restrain the rotation of the rod by using the load acting on the scaffold.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, the locking device, the piston rod which is lowered by the hydraulic oil supplied through the hydraulic port for unlocking the device at the same time the hydraulic oil is supplied to one of the hydraulic port. And a fixed block installed at the piston rod and coupled to a thread of the rotating body to restrain or release the rotating body, and a spring positioned below the fixing block to return the fixed block to the restraining position. Characterized in that.

In addition, according to the hydraulic jack having a threaded locking device of the present invention, the restraint function for the rotating body is characterized in that it is made automatically by the spring.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, when the hydraulic oil is supplied to one of the selected hydraulic port includes a release valve for automatically supplying the hydraulic oil to the hydraulic port for releasing the locking device Characterized in that the provided hydraulic circuit.

In the hydraulic jack having a screw locking device of the present invention, the guide shaft installed in the cylinder and the nut installed on the rod are screwed together, and the locking device restrains the rotating body installed on the upper end of the guide shaft, so that the position of the rod is fixed to detect the piston position. There is an effect that can be fixed position for a long time without using the means or control means.

In addition, according to the hydraulic jack provided with a threaded locking device of the present invention, by using the ball screw structure to change the vertical movement of the rod to the rotational movement of the guide shaft, there is an effect that the movement and the movement of the rod can be easily made. .

In addition, according to the hydraulic jack provided with a threaded locking device of the present invention, the rod and the footrest is connected to the universal joint, the relative movement of the footrest to the rod is possible, and the rod is not rotated by using the load acting on the footrest up and down You can only move to.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, when the hydraulic oil is supplied to raise and lower the rod, the fixed block is lowered to release the restraint of the rotating body, thereby enabling the rod to be elevated.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, if the hydraulic oil is not supplied to the locking device, the fixed block is raised by the action of the spring to restrain the rotating body, thereby automatically restraining the rotating body and the rod There is an effect of fixing so as not to move up and down.

In addition, according to the hydraulic jack having a screw-type locking device of the present invention, when constituting the hydraulic circuit for the control of the hydraulic jack, when the hydraulic oil is supplied for the lifting of the rod to release the lock release valve to release the restraint to the rotating body; In addition, there is an effect that can release the restraint rod without using a separate additional device.

Hereinafter, with reference to the accompanying drawings illustrating a hydraulic jack having a screw-type locking device of the present invention.

Figure 2 is a schematic view showing a hydraulic jack having a screw locking device according to the present invention, Figure 3 is a schematic diagram schematically showing a locking device which is a main component of the present invention, Figure 4 is an expansion in the hydraulic jack of the present invention It is a reference diagram showing the city. And, Figure 5 is a reference view showing a state when the position fixed in the hydraulic jack of the present invention, Figure 6 is a reference view showing a state when reduced in the hydraulic jack of the present invention, Figure 7 is used in the hydraulic jack of the present invention Hydraulic circuit diagram.

Hydraulic jack having a screw-type locking device according to the present invention, the cylinder 10 and the hydraulic ports 11, 12 are installed at the top and bottom, respectively; A rod 15 which is lifted up and down inside the cylinder 10 according to the supply of hydraulic oil through the hydraulic ports 11 and 12; A footrest 18 connected to the lower end of the rod 15; A universal joint (17) for restraining rotation of the rod (15) by using a load acting on the scaffold (18); A guide shaft 14 rotatably installed in the cylinder 10 and having a screw thread formed on an outer circumferential surface thereof; A nut (16) installed at an upper end of the rod (15) and screwed to the guide shaft (14) to rotate the guide shaft (14) as the rod (15) moves up and down; A rotating body 13 installed at an upper end of the guide shaft 14 and having a thread 13 'formed on an outer circumferential surface thereof; A locking device (20) installed inside the cylinder (10) to restrain or release the rotating body (13) in accordance with the supply of hydraulic oil; It comprises a hydraulic circuit 30 for supplying the hydraulic oil to a selected place of the hydraulic port (11, 12).

Here, it is preferable that a plurality of balls (not shown) are provided between the guide shaft 14 and the nut 16 to form a ball screw structure. The ball screw structure is an assembly of the guide shaft 14, the nut 16 and the ball, and converts the vertical movement of the rod 15 into the rotational movement of the guide shaft 14.

At this time, it is obvious that the threaded portion formed of the guide shaft 14 and the nut 16 should not satisfy the self-supporting condition so that the rod 15 can move. Specifically, the threads formed on the guide shaft 14 and the nut 16 should be formed to satisfy the following conditions.

That is, since the rod 15 can move up and down only when the inclination angle of the screw is larger than the friction angle, the lead and radius of the thread formed on the guide shaft 14 and the nut 16 must be set to satisfy the above condition. do.

On the other hand, the locking device 20, at the same time the hydraulic oil is supplied to one of the hydraulic port (11, 12) and at the same time the piston rod 22 that is lowered by the hydraulic oil supplied through the hydraulic port 21 for releasing the locking device. And a fixed block 25 installed at the piston rod 22 and having one side coupled to the thread 13 'of the rotating body 13 to restrain or release the rotating body 13, and the fixed block. Located at the bottom of the (25) includes a spring 23 for returning the fixing block 25 to the restrained position, and a spring seat 24 for supporting the spring (23). Therefore, the restraint function for the rotating body 13 is automatically made by the spring 23.

The hydraulic circuit 30 includes a direction control valve 31 for selectively supplying hydraulic oil to one of the hydraulic ports 11 and 12, and hydraulic oil at any one of the hydraulic ports 11 and 12. Is provided between the release control valve 33 and the directional control valve 31 and the release control valve 33 to automatically supply the hydraulic oil to the lock release hydraulic port 21 when it is supplied. It includes a pair of check valve (32).

The hydraulic jack having the screw locking device of the present invention configured as described above is expanded when hydraulic oil is supplied to the upper hydraulic port, and is reduced when hydraulic oil is supplied to the lower hydraulic port, and the rotating body is constrained when the hydraulic oil is not supplied. And not rotated to fix the position of the threaded rod.

When the directional control valve 31 of the hydraulic circuit 30 is operated to the expansion side in order to expand the hydraulic jack, the hydraulic oil is supplied to the upper hydraulic port 11 and the hydraulic oil under the rod 15 passes through the lower hydraulic port 12. Will go out. At this time, the hydraulic oil supplied to the release control valve 33 through the check valve 32 operates the release valve 33 to supply hydraulic oil to the hydraulic port 21 for releasing the lock. Therefore, as the piston rod 22 of the locking device 20 descends, the restraint of the rotor 13 by the fixing block 25 is released to allow the rotor 13 to be rotated.

When the restraint of the rotor 13 is released as described above, the guide shaft 14 on which the rotor 13 is installed may also be rotated. In this state, the hydraulic pressure applied to the upper side of the rod 15 is acted on by the hydraulic oil supplied to the upper hydraulic port 11, and the rod 15 is lowered accordingly. When the rod 15 is lowered, the guide shaft 14 and the rotating body 13 screwed to the nut 16 installed on the rod 15 rotate. At this time, the rod 14 does not rotate due to the footrest 18 connected to the rod 14 by the universal joint 17.

When the hydraulic jack is expanded as necessary through the above process, the position of the rod 15 can be fixed by operating the direction control valve 31 to the fixed side. When the directional control valve 31 is located on the fixed side, the supply of hydraulic oil to the upper hydraulic port 11 is stopped, whereby the operation of the release operation valve 33 is stopped to release the lock. Hydraulic fluid is also not supplied to the hydraulic port 21. Therefore, the fixing block 25 is raised by the action of the spring 23 located below the fixing block 25 and engaged with the thread 13 'of the rotating body 13, whereby the rotating body 13 Is constrained so that it cannot be rotated.

As such, when the rotating body 13 is restrained, the guide shaft 14 is also restrained, and lifting of the rod 15 on which the nut 16 screwed to the guide shaft 14 is impossible is possible. Therefore, the position of the rod 15 is fixed, and as the position of the rod 15 is fixed, the size of the hydraulic jack is fixed without expanding or contracting. As such, the necessary work is performed while the position of the rod 15 is fixed, so that a problem due to expansion or contraction of the hydraulic jack does not occur during the operation.

In order to reduce the hydraulic jack after the operation is completed, the direction control valve 31 of the hydraulic circuit 30 may be operated to the reduction side. When the directional control valve 31 is located on the reduction side, the hydraulic oil is supplied to the lower hydraulic port 12 and the hydraulic oil above the rod 15 exits through the upper hydraulic port 11. At this time, the hydraulic oil is supplied to the release valve 33 through the check valve 32, the release valve 33 is operated by the hydraulic oil to the hydraulic port 21 for releasing the lock. Hydraulic oil is supplied. Therefore, the piston rod 22 of the locking device 20 is lowered, thereby releasing the restraint of the rotor 13 by the fixing block 25 so that the rotor 13 can be rotated. At this time, since the amount of hydraulic oil supplied to the lock release device hydraulic port 21 is less than the hydraulic oil supplied to the lower hydraulic port 12, the hydraulic oil supplied to the lock release device hydraulic port 21 is It does not happen to disturb the rise of the rod 15.

As such, when the restraint of the rotor 13 is released, the guide shaft 14 may also be rotated. In this state, the hydraulic pressure applied to the lower side of the rod 15 is acted on by the hydraulic oil supplied to the lower hydraulic port 12, and the rod 15 is raised accordingly. When the rod 15 is raised, the guide shaft 14 and the rotor 13 screwed to the nut 16 installed on the rod 15 rotate, but the universal joint ( The rod 14 does not rotate due to the footrest 18 connected to 17.

Of course, even when the hydraulic jack is reduced as described above, if the supply of the hydraulic oil is interrupted through the directional control valve 31, the locking device 20 is operated so that the position of the rod 15 is fixed. That is, when the direction control valve 31 is located on the fixed side, the supply of hydraulic oil to the lower hydraulic port 12 is stopped, and the operation of the release lock operation valve 32 is also stopped to release the lock. Hydraulic fluid is also not supplied to the hydraulic port 21. Therefore, the fixing block 25 is raised by the action of the spring 23 located below the fixing block 25 and engaged with the thread 13 'of the rotating body 13, whereby the rotating body 13 Is constrained so that it cannot be rotated.

As such, when the rotating body 13 is restrained, the guide shaft 14 is also restrained, and lifting of the rod 15 on which the nut 16 screwed to the guide shaft 14 is impossible is possible. Therefore, the position of the rod 15 is fixed, and as the position of the rod 15 is fixed, the hydraulic jack stops shrinking and its size is fixed. As such, if the necessary work is performed while the position of the rod 15 is fixed, the problem due to expansion or contraction of the hydraulic jack does not occur during the work.

As described above, in the present invention, when the hydraulic oil is supplied to the upper hydraulic port 11 or the lower hydraulic port 12, the restraint of the rotating body 13 by the locking device 20 is released, thereby raising and lowering the rod 15. Or otherwise, the fixing block 25 of the locking device 20 is lifted by the spring 23 to restrain the rotating body 13, so that the lifting of the rod 15 is restricted and the The position is fixed. Therefore, the position of the rod 15 can be fixed only by interrupting supply of hydraulic oil without installing a separate auxiliary device.

Although the present invention has been described in more detail with reference to the embodiments, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are merely described the technical idea of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. As a result, the protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a reference diagram for explaining the principle of the hydraulic jack.

Figure 2 is a block diagram showing a hydraulic jack having a threaded locking device according to the present invention.

Figure 3 is a schematic diagram schematically showing a locking device of the main configuration of the present invention.

Figure 4 is a reference view showing a state when expanded in the hydraulic jack of the present invention.

Figure 5 is a reference diagram showing the state at the position fixed in the hydraulic jack of the present invention.

Figure 6 is a reference view showing a state when reduced in the hydraulic jack of the present invention.

7 is a hydraulic circuit diagram used in the hydraulic jack of the present invention.

<Explanation of symbols for main parts of the drawings>

10: Cylinder 11: Top Hydraulic Port

12: Lower hydraulic port 13: Rotating body

14: guide shaft 15: rod

16: nut 17: universal joint

18: scaffolding

20: Locking device 21: Hydraulic port for unlocking device

22: piston rod 23: spring

24: spring seat 25: fixed block

30: hydraulic circuit 31: directional control valve

32: Check valve 33: Release valve

Claims (6)

A cylinder 10 having hydraulic ports 11 and 12 installed at upper and lower ends thereof, respectively; A rod 15 which is lifted up and down inside the cylinder 10 according to the supply of hydraulic oil through the hydraulic ports 11 and 12; A footrest 18 connected to the lower end of the rod 15; A guide shaft 14 rotatably installed in the cylinder 10 and having a screw thread formed on an outer circumferential surface thereof; A nut (16) installed at an upper end of the rod (15) and screwed to the guide shaft (14) to rotate the guide shaft (14) as the rod (15) moves up and down; A rotating body 13 installed at an upper end of the guide shaft 14 and having a thread 13 'formed on an outer circumferential surface thereof; And a locking device (20) installed inside the cylinder (10) to restrain or release the rotating body (13) in accordance with the supply of hydraulic oil. The locking device 20, and the piston rod 22 is lowered by the hydraulic oil supplied through the hydraulic port 21 for releasing the locking device at the same time the hydraulic oil is supplied to one of the hydraulic port (11) (12) and , A fixed block 25 installed on the piston rod 22 and coupled to a thread 13 ′ of the rotating body 13 to restrain or release the rotating body 13, and the fixed block 25. Located in the bottom of the hydraulic jack having a screw-type lock device, characterized in that it comprises a spring (23) for returning the fixed block (25) to the restrained position. The method of claim 1, A ball screw structure in which a plurality of balls are installed between the guide shaft 14 and the nut 16 is formed so as to convert the vertical motion of the rod 15 into the rotational motion of the guide shaft 14. Hydraulic jack with sandal lock. The method of claim 1, Hydraulic jack having a screw-type locking device, characterized in that the universal joint (17) is further provided to restrain the rotation of the rod (15) by using the load acting on the footrest (18). delete The method according to any one of claims 1 to 3, Restraint function for the rotating body 13 is a hydraulic jack having a screw-type locking device, characterized in that made automatically by the spring (23). The method according to any one of claims 1 to 3, Hydraulic circuit 30 including an unlocking operation valve 33 for automatically supplying hydraulic oil to the hydraulic port 21 for releasing the locking device when the hydraulic oil is supplied to one of the hydraulic ports 11 and 12. Hydraulic jack having a screw-type locking device, characterized in that it comprises a).

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