KR820001391B1 - Control valve assembly - Google Patents

Abstract

A hydraulic control valve(20) controls the movement of a fluid powered motor. The valve comprises a manually slidable spool(40) which allows hydraulic fluid to be selectively introduced into the fluid powered motor(13). The valve also includes a piston stem valve(70) which prevents actuation of the fluid motor in a specific direction unless the pressure in the load chamber of the fluid motor exceeds the pressure in the venting chamber by a predetermined amount. The normally closed tiltable check valve including a compressing spring biased tiltable seal.

Description

Control valve device

1 is a cross-sectional view of a hydraulic control valve device in which the control spool is located at the neutral position N. FIG.

2 is a cross-sectional view of the hydraulic control valve device in which the control sprue is in the first operating position B. FIG.

3 is a sectional view of a hydraulic control valve device in which the control sprue is located in the second operating position A. FIG.

3A is a cross-sectional view of a portion of a control valve device showing that the control sprue is moved to the second operating position A and the hydraulic fluid force actuates the piston to open the check valve.

The present invention relates to a novel control valve arrangement suitable for use in controlling the movement of a fluid powered motor, and in particular, a spool type hydraulic control valve interrelated with a stem type check valve arrangement. It is about.

Fluid power motors have many uses, for example, to control the rotational movement of a loaded forklift arm. A serious problem arises when the elevated cargo is to be rotated away from the motor device due to the weight of the cargo, since the drive chamber tends to be faster than the speed at which the drive chamber is filled with pressurized hydraulic fluid. The lack of sufficient hydraulic fluid causes severe damage to the forklift mechanism by creating a cavity in the base that prevents the fluid-powered motor from accurately controlling and stopping the rotary motion of the elevated cargo.

In order to solve the above problems, attention has been paid to various control devices having a tilt lock and a check valve device.

None of the prior art devices known to the inventors have been satisfied to provide an economical and single device for actively controlling the movement of a fluid powered motor that prevents leakage of the hydraulic fluid network caused by the weight of the cargo. .

SUMMARY OF THE INVENTION An object of the present invention is to provide an economical control valve device for actively controlling the motion of a fluid power motor device having various loading states.

It is another object of the present invention to provide a simplified control device having an inclination fixing mechanism associated with a check valve device that prevents leakage of hydraulic fluid as well as unregulated movement of a fluid powered motor.

Still another object of the present invention is to prevent the hydraulic fluid from leaving the discharge chamber of the fluid motor until a sufficient amount of hydraulic fluid enters the drive chamber, and excludes the influence of the weight of the cargo so that the cargo is only loaded by the fluid motor device. To provide a control valve device to ensure that the movement of the control is controlled.

The hydraulic control valve device of the present invention includes a control sprue member suitable for being manually set in one of three control positions. When the control spun member is in the neutral position, it prevents hydraulic fluid from entering or exiting the fluid powered motor and its associated fluid pipe. When it is required to rotate the lifted cargo, the control sprue is manually moved to one of two operating positions. The hydraulic fluid pressurized by the movement of the control sprue in the first operating position opens the stem type check valve and flows into one chamber of the fluid-powered motor, and the hydraulic fluid in the chamber opposite to the motor And into the storage tank, whereby the fluid motor operates to rotate the cargo lifted in the first direction relative to the fork lift car (forklift).

When the control sprue is moved to the second operating position, the pressurized hydraulic fluid flows directly into one chamber of the fluid motor, and the hydraulic fluid already present in the chamber opposite the fluid motor has a pressure in the drive chamber that is higher than the pressure in the discharge chamber. Exhaust is prevented by the check valve device until it exceeds a predetermined amount, and when the piston located in the control sprue opens the stem type check valve, the hydraulic fluid is discharged from the control motor. This causes the control motor to rotate the lifted cargo by a predetermined amount such that the pressure of the hydraulic fluid in the drive chamber exceeds the pressure of the hydraulic fluid in the discharge chamber.

Other advantages of the present invention will become apparent from the following description.

The hydraulic control valve device according to the present invention will be described in more detail with reference to the accompanying drawings.

In FIG. 1, the numeral 10 represents a forklift type vehicle (forklift), and a support arm 11 is attached to the rotating shaft on the vehicle body 12 of the forklift 10. The support arm 11 supports the lifted cargo L and is selectively rotated by the operation of the fluid-powered motor device 13. The motor apparatus 13 is attached to the vehicle body 12, and has the connecting rod 14 attached to the support arm 11 so that it may rotate. The motor has a set of fluid chambers 15 and 16 separated by a piston 17 integrally attached to the connecting rod 14.

The fluid powered motor 13 selectively operates to rotate the support arm 11 by injecting hydraulic fluid into one of the fluid chambers 15 or 16 and simultaneously discharging the remaining fluid chamber. If one of the fluid chambers is discharged faster than the drive chamber can be filled, the piston 17 is pulled further towards the discharge chamber by the weight of the cargo and allows the position of the support arm 11 and the cargo L to be precisely adjusted. This creates a cavity in the bush that reduces the performance of the fluid motor 13. As will be described later, the present invention provides a control valve device that actively prevents the generation of cavities in the fluid motor 13 and also prevents any hydraulic fluid from leaking through the control valve device. The hydraulic control valve device 20 has a set of hydraulic fluid ports 21 and 22 with a set of fluid conduits 18 and 19, the fluid conduits 18 and 19 having a fluid port of the control valve device 20. It extends between 21 and 22 and the fluid chambers 15 and 16 of the fluid motor 13. The constant capacity pump p (not shown) draws pressurized hydraulic fluid which is selectively introduced into the fluid chamber 15 or 16 of the motor 13 via either the fluid port 21 or 22 of the valve 20. Supply.

The control valve device 20 has a valve body 23 including a central passage 24, and the central passage 24 extends in the longitudinal direction of the valve body. The valve body 23 also has a number of cavities 25-33 in communication with the central passage 24. The cavities 25, 28, 30 and 33 are connected to the common hydraulic fluid storage tank T by fluid passages (shown in phantom), respectively, and the cavities 26 and 32 are fluid balls 21 and 22. Are each connected to. The cavities 27, 29 and 31 are connected directly to the pump p via a central passage 34 and additional connecting passages 35, 36 and 37, respectively.

In the cylindrical spool member 40, a plurality of thick portions 41-45 are interposed therebetween and are arranged to be active in the passage 24. The sprue 40 is deflected to the first or neutral position N by a pressing spring 46 that engages a set of circular flange members 47 and 48 mounted thereto. The frame 49 surrounds the spring 46 and has a known vent 50.

The sprue 40 also has a number of connections 51-54 having reduced diameters interconnected with the thick portions 41-45, respectively. The connecting portion 51 includes a set of curved ends connected to the thick portions 41 and 42. The connecting portions 52 and 53 are tapered from the thick portions 42 and 44 to the inner wall of the thick portion 43, respectively.

The sprue 40 has a shaft hole 55 closed at both ends, the shaft hole partially extending inside the spool, and having a first cylindrical portion 56 having an enlarged diameter and a second having a reduced diameter. It has an adjacent cylindrical part 57. A narrow outlet 58 extends from the passage 24 through the spout 40 into the portion 57 of the inner shaft hole 55.

The cylindrical piston 60 is operatively disposed in the first cylindrical portion 56 between the end wall where the two cylindrical portions 56 and 57 meet and the separate stop 61. The stopper 61 has a rod member 62 which extends beyond the stopper. The stopper 61 is supported by the support member 63. A hollow flange member 64 deflected in contact with the sprue 40 by the pressing spring 65 disposed between the support member 63 and the flange 64 is mounted at one end of the rod 62. have.

The stem type check valve apparatus 70 has a screw portion 71 suitable for being fitted into a screw portion 72 formed in the valve body 23 of the control valve apparatus 20.

The check valve device 70 also has a fluid passage 73 extending from the fluid sphere 22 to the cavity 32. A set of hollow elastic suture rings 74 and 75 are arranged in the passage 73 and spaced apart. The sealing ring 74 is disposed at a curved portion (FIG. 3A 76) inward of the check valve device 70, and the sealing ring 75 is inwardly of the check valve device 70 by the pressing spring 78. It is pressed so that it may be arrange | positioned to the extension boss part 77. As shown in FIG. The spring 78 is urged between the elastic ring 75 and the cylindrical elastic closure member 79.

The sealing member 79 is urged by the spring 78 to contact the hollow ring 74, and the sealing member 79 has a diameter sufficient to block the fluid passage 73 passing through the hollow ring 74. have. The sealing member 79 also has a plurality of grooves 80 that allow fluid to flow past the member 79 at a particular time, which will be described below. Finally, the sealing member 79 is mounted to the rod 81, which rod is a cylindrical part of the shaft hole 55 through an elongate groove that is dug on the passage 73, the cavity 32, the sprue 40. It extends into 56.

The operation of the preferred embodiment of the present invention is described with reference to the accompanying drawings.

In FIG. 1, the control valve device 20 is located at the neutral position N connected to the spool 40 by an imaginary line. Hydraulic fluid pressurized by the pump p enters the cavity 29 through the passages 34 and 36. Because of the location of the spool 40, hydraulic fluid can pass directly into the cavities 28 and 30, as indicated by the arrows. The hydraulic fluid then flows directly into storage tank T.

The fluid sphere 21 is blocked in communication with either the pump P or the tank T by the position of the spun 40. In a similar manner, the check valve 70 prevents fluid from being discharged from the fluid chamber 16 of the motor device 13 through the valve device 20, and the spool 40 itself is provided with additional hydraulic fluid. By leaving the fluid motor 13, the fluid in the fluid chambers 15 and 16 remains unchanged to prevent the support arm 11 and the cargo L from rotating in either direction with respect to itself 12.

In FIG. 2, the sprue 40 is manually moved to the B position indicated by the imaginary line. This opens the fluid passageway between the cavities 26 and 25 and causes the hydraulic fluid in the fluid chamber 15 to be discharged to the storage tank T. Portions of the spoof 40 are in place to seal the passage between the cavities 28, 29 and 30, with a new passage simultaneously between the pump P, the passage 37, the cavities 31 and the cavities 32. Open. The pressurized hydraulic fluid overcomes the pressing spring 78 and presses the sealing member 79 to release the contact with the sealing ring 74. Next, the hydraulic fluid may flow directly into the fluid chamber 16 through the groove 80. The increased pressure in the chamber 16 pushes the piston 17 and the rod 14 toward the discharge chamber 15, thereby rotating the support arm 11 counterclockwise. If the sprue 40 is selectively relocated to the N position, the support arm 11 and the cargo L are fixed in the air relative to the body 12.

When the control valve device 20 is selectively moved to the A position, the sprue 40 is in the position shown in FIG.

Hydraulic fluid from the pump P can only be moved to the cavity 26 via the passages 34 and 35, the cavity 27. The pressurized fluid then flows through the fluid tube 18 into the chamber 15 of the fluid motor 13. When fluid pressure builds up in the seal 15, the piston 17 tries to move towards the seal 16 but cannot because of the check valve 70. Thus, pressure is continuously formed in the chamber 15.

Hydraulic fluid that is continuously pumped into the cavity 29 flows through the discharge hole 58 to the cylindrical portion 57 of the shaft hole 55. Referring to FIG. 3A, the hydraulic fluid continues to fill the portion 57 and eventually contacts the end of the cylindrical piston 60 to move the piston 60 into engagement with the rod 81. After a predetermined pressure is formed in the shaft hole 55, the piston 60 presses the rod 81 to continue to incline to open the check valve 70. The piston 60 continues to tilt the rod 81 until it comes into contact with the rod 62. Since the check valve 70 is open, the hydraulic fluid in the seal 16 is discharged to the storage tank T so that the piston 17 and the rod 14 rotate the support arm 11 clockwise.

In addition to selecting a particular spring 78, as well as careful design of the cylindrical portions 56 and 57 of the shaft hole 55, the check valve 70 has a fluid pressure in the seal 15, It can be opened when it exceeds a more predetermined amount, and there is always enough fluid in the seal 15 to prevent cavitation.

It is important that as soon as the control valve device 20 is repositioned to the neutral position N, the check valve 70 is closed due to the fluid passage existing between the pump P and the storage tank T. Thereby, the driver controls the support arm 11 and the lifted cargo L. FIG.

Claims (1)

In the hydraulic control valve device 20 for controlling the operation of the fluid motor 13 having the first and second fluid chambers 15 and 16, the central passage 24 and the hydraulic fluid supply source are selectively interconnected. A plurality of interconnected fluid conduits (35-37) and a plurality of cavities (25-33) spaced apart from each other in communication with the passageway and the fluid reservoir, and further comprising the first and second of the fluid motor (13). A valve body 23 having the first and second connectors 18 and 19 connecting the two fluid chambers 15 and 16 and two of the cavities 25 to 33 and the second connector 19; Normally closed check valve assembly 70 disposed in the fluid passage 73 between adjacent cavities 32 and a cylindrical connection 51-54 having a reduced diameter and operatively disposed within the central passage 24. It has a plurality of cylindrical coarse portions (41-45) interconnected by, the hydraulic fluid does not enter or exit the fluid motor (13) And the normally closed check valve 70 is opened so that the fluid enters the second fluid chamber 16 of the fluid motor 13 and at the same time the fluid in the first fluid chamber 15 An elongated sprue member 40 operable between a first operating position to be discharged to the fluid reservoir and a second operating position to which the fluid enters the first fluid chamber 15 of the fluid motor 13 directly; And the second fluid chamber only when the fluid pressure in the first fluid chamber 15 exceeds the fluid pressure in the second fluid chamber 16 by a predetermined amount and when the spoof member is in the second operating position. And a member adapted to the position of the spoof member for opening the check valve (70) to discharge the fluid from the (16).

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