CN110864028A

CN110864028A - Engineering machinery damping control valve

Info

Publication number: CN110864028A
Application number: CN201911194179.8A
Authority: CN
Inventors: 陈艳艳; 张庆宇
Original assignee: Ningbo Wen Fan Electrical And Mechanical Technology Development Co Ltd
Current assignee: SHANGHAI NUOMA HYDRAULIC SYSTEM Co.,Ltd.
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-03-06
Anticipated expiration: 2039-11-28
Also published as: CN110864028B

Abstract

The invention discloses a vibration reduction control valve for engineering machinery, which comprises a valve sleeve, a threaded sleeve and a reversing valve core, wherein the threaded sleeve is in threaded connection with the upper end of the valve sleeve; the reversing valve core is rotatably connected in the reversing valve hole, and a transmission block is fixedly arranged at the upper end of the reversing valve core; the upper end of the valve sleeve is provided with an arc-shaped cutting groove communicated with the reversing valve hole, and the circumferential side surface of the transmission block is provided with a convex column extending into the arc-shaped cutting groove; when the convex column is positioned at one end of the arc-shaped cutting groove, the reversing valve core is positioned at an initial position, and the port P, the port A, the port B and the port T are not communicated with each other; when the convex column is positioned at the other end of the arc-shaped cutting groove, the reversing valve core rotates to enable the port P to be communicated with the port A through the second annular groove and the first cutting groove, and the port T is communicated with the port B through the arc-shaped groove and the second cutting groove; a pressure reducing valve piece for controlling the pressure of the port P to be the same as that of the port A is arranged in the reversing valve core; the damping control valve for the engineering machinery not only has simple structure and compact volume, but also can effectively realize the damping of the engineering machinery.

Description

Engineering machinery damping control valve

Technical Field

The invention belongs to the technical field of engineering machinery, and particularly relates to a damping control valve of engineering machinery.

Background

Wheel-side supports of engineering machinery such as loaders, skid loaders, backhoe loaders and telescopic arm forklifts are rigidly connected with a frame, and excitation vibration caused by uneven road surfaces is completely borne by four tires. When the engineering machinery runs or works, the movable arm oil cylinder does not act, the movable arm oil cylinder and the front frame are in rigid connection, the whole vehicle can swing around the front axle as a center under the action of road conditions and tires, the situation that the rear axle is separated from the ground can be caused sometimes, a driver can swing along with the whole vehicle at the moment, the operation and the control are difficult, and the driving comfort is poor. Because the working device, heavy objects and other parts of the machine body react to bumpy bottom surfaces or obstacles, strong vibration and impact are generated, and the smoothness and the stability of the running of the whole machine are seriously influenced. Such vibration during the traveling of the construction machine may cause alternating stress and fatigue damage to the working devices, the front and rear frames, the drive axle, and the like; meanwhile, as the working device is supported by the movable arm oil cylinder, the vibration impacts a hydraulic system, and adverse effects are generated on hydraulic elements and sealing; the vibration of the vehicle also causes bucket material to spill, the running speed cannot be provided, a driver is uncomfortable to ride, and driving batch is easy to generate, which all affect the working efficiency.

In the prior art, although the damping function of the loader during the running process can be realized to a certain extent as in the patent with application number 201210197132.9 entitled "damping device for a mobile arm of a skid steer loader" and the patent with application number 200420092138.0 entitled "running stabilizing device for a wheel loader", the following disadvantages exist:

(1) in the two technologies, because the energy accumulator is controlled to be communicated with the rodless cavity of the movable arm oil cylinder through the electromagnetic valve to charge liquid in a certain operation process, when the vibration reduction function is realized due to the fact that the size of each load is unequal, the pressure of the movable arm oil cylinder is unequal to the pressure of the energy accumulator, so that the movable arm oil cylinder is suddenly extended or retracted, and further bucket materials are scattered;

(2) in the two technologies, when the pressure of the energy accumulator is low, if the energy accumulator is filled with liquid in the operation process, the output flow of the hydraulic pump firstly enters the energy accumulator, and then the movable arm oil cylinder is driven to act, so that the movable arm is weak and cannot normally operate.

Disclosure of Invention

Technical problem to be solved

The invention aims to provide a damping control valve which is simple in structure, compact in size and capable of effectively realizing running buffering of engineering machinery.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a vibration reduction control valve for engineering machinery comprises a valve sleeve, a threaded sleeve and a reversing valve core, wherein a reversing valve hole with an opening at the upper end is formed in the valve sleeve, and the threaded sleeve is in threaded connection with the upper end of the valve sleeve; the reversing valve core is rotatably connected in the reversing valve hole, a transmission block is fixedly mounted at the upper end of the reversing valve core, and the transmission block is rotatably connected in the reversing valve hole; the upper end of the valve sleeve is provided with an arc-shaped cutting groove communicated with the reversing valve hole, and the circumferential side surface of the transmission block is provided with a convex column extending into the arc-shaped cutting groove; the side surface of the valve sleeve is sequentially provided with an X port, a P port, a T port, a B port and an A port which are communicated with the reversing valve hole from top to bottom, and the lower end of the reversing valve hole in the valve sleeve is provided with an oil hole communicated with the A port; the circumferential side surface of the reversing valve core is provided with a first annular groove communicated with the X port, a second annular groove communicated with the P port and an arc-shaped groove communicated with the T port; a first cutting groove communicated with the second annular groove and a second cutting groove communicated with the arc-shaped groove are formed in the circumferential side surface of the reversing valve core along the axial direction of the reversing valve core; when the convex column is positioned at one end of the arc-shaped cutting groove, the reversing valve core is positioned at an initial position, and the port P, the port A, the port B and the port T are not communicated with each other; when the convex column is positioned at the other end of the arc-shaped cutting groove, the reversing valve core rotates to enable the port P to be communicated with the port A through the second annular groove and the first cutting groove, and the port T is communicated with the port B through the arc-shaped groove and the second cutting groove; and a pressure reducing valve piece for controlling the pressure of the port P to be the same as that of the port A is arranged in the reversing valve core.

In a further technical scheme, the pressure reducing valve comprises a pressure reducing valve core, a control rod, an upper spring, a lower spring and a hollow plug, a pressure reducing valve hole with an opening at the upper end is formed in the reversing valve core, and the pressure reducing valve core is rotatably connected in the pressure reducing valve hole; the transmission block is provided with a stud which is in threaded connection with an opening at the upper end of the pressure reducing valve hole; a second shaft hole which penetrates through the reversing valve core is arranged in the middle position of the bottom of the pressure reducing valve hole in the reversing valve core, a first shaft hole which penetrates through the reversing valve core is arranged in the pressure reducing valve core, and the first shaft hole and the second shaft hole are coaxially arranged; the upper end of the control rod is connected in the first shaft hole in a sliding manner, and the lower end of the control rod is connected in the second shaft hole in a sliding manner; the inner side wall of the second shaft hole is provided with limiting sliding grooves which are symmetrical in position along the axial direction of the inner side wall, and the outer circumferential side surface of the control rod is provided with a limiting bulge which is connected in the limiting sliding grooves in a sliding manner; the side wall of the inner circumference of the first shaft hole is provided with a spiral groove, and the side surface of the outer circumference of the control rod is provided with a cylinder extending into the spiral groove;

the upper end of the first shaft hole is provided with a first spring hole, the lower end of the second shaft hole is provided with a second spring hole, and the hollow plug is installed at the lower end of the second spring hole; the upper spring is positioned in the first spring hole, the upper end of the upper spring is abutted against the upper end of the stud, and the lower end of the upper spring is abutted against the lower end of the first spring hole through the hollow lower gasket; the lower spring is positioned in the second spring hole, the lower end of the lower spring abuts against the upper end of the hollow plug, and the upper end of the lower spring abuts against the upper end of the second spring hole through the hollow upper gasket; a first through hole for communicating the first annular groove with the pressure reducing valve hole, a second through hole for communicating the second annular groove with the pressure reducing valve hole and a third through hole for communicating the arc-shaped groove with the pressure reducing valve hole are formed in the reversing valve core; a third annular groove communicated with the second through hole is formed in the side face of the outer circumference of the pressure reducing valve core, a third cutting groove communicated with the third annular groove is formed in the side face of the circumference of the pressure reducing valve core downwards along the axial direction of the pressure reducing valve core, and a fourth cutting groove and a fifth cutting groove communicated with the third annular groove are formed in the side face of the circumference of the pressure reducing valve core upwards; a sixth cutting groove used for communicating the fifth cutting groove with the first spring hole is formed in the pressure reducing valve core; when the pressure of the port A is equal to the pressure of the port P, the pressure reducing valve core is in the first position, and the port P, the port T and the port X are not communicated with each other; when the pressure of the port A is higher than that of the port P, the pressure reducing valve core is located at a third position, and the port P is communicated with the port X through a second annular groove, a second through hole, a third annular groove, a fourth cutting groove, a first through hole and a first annular groove; when the pressure of the port A is smaller than that of the port P, the pressure reducing valve core is located at the second position, and the port P is communicated with the port T through the second annular groove, the second through hole, the third annular groove, the third cutting groove, the third through hole and the arc-shaped groove.

In a further technical scheme, the upper end of the transmission block is provided with a rotating shaft which is rotatably connected in the threaded sleeve, the threaded sleeve is fixedly provided with a stepping motor, the output shaft of the stepping motor is fixedly connected with the rotating shaft, and the stepping motor is used for driving the transmission block to rotate through the rotating shaft.

In a further technical scheme, a first positioning groove and a second positioning groove are arranged on the inner side wall of the reversing valve hole at positions close to the upper end, a mounting hole is radially formed in the outer circumferential side face of the transmission block, and a positioning steel ball and a positioning spring for forcing the positioning steel ball to press the inner side wall of the reversing valve hole are arranged in the mounting hole; when the convex column is positioned at one end of the arc-shaped cutting groove, the positioning steel ball is pressed in the first positioning groove under the action of the positioning spring; when the convex column is positioned at the other end of the arc-shaped cutting groove, the positioning steel ball is pressed in the second positioning groove under the action of the positioning spring.

In a further technical scheme, the upper end of the reversing valve hole is provided with a torsional spring which is sleeved at the upper end of the transmission block and used for forcing the convex column to move towards one end of the arc-shaped cutting groove.

(III) advantageous effects

Compared with the prior art, the technical scheme of the invention has the following advantages:

when the hydraulic buffer device is used, automatic buffering in the running process of the engineering machinery can be realized, the pressure in the energy accumulator (namely the pressure of the port P) is controlled to be always equal to the pressure of the port A through the pressure reducing valve core, the sudden extension or retraction of the oil cylinder when the running buffering is switched from operation can not occur, and the buffering effect is better; and because the liquid is filled by the independent hydraulic pump under the control of the pressure reducing valve core, the phenomenon that the movable arm oil cylinder is weak and weak in the prior art is avoided; the invention has the advantages of high integration, compact volume, simple structure and low manufacturing cost.

Drawings

FIGS. 1-2 are schematic three-dimensional structures of the present invention;

FIG. 3 is a schematic view of a partially assembled structure of the present invention;

FIG. 4 is a front view of the present invention;

FIG. 5 is a top view of the present invention;

FIG. 6 is a rear view of the present invention;

FIG. 7 is a cross-sectional view taken along line A-A of FIG. 6 with the diverter spool in the initial position;

FIG. 8 is a cross-sectional view taken along line D-D of FIG. 7;

FIG. 9 is a cross-sectional view A-A of FIG. 6 with the diverter spool in the diverting position;

FIG. 10 is a cross-sectional view taken along line E-E of FIG. 9;

FIG. 11 is a cross-sectional view taken along line C-C of FIG. 4, with the pressure relief valve spool in a first position;

FIG. 12 is a cross-sectional view B-B of FIG. 5, with the pressure relief valve spool in a first position;

FIG. 13 is a cross-sectional view taken along line C-C of FIG. 4, with the pressure relief valve spool in a second position;

FIG. 14 is a cross-sectional view B-B of FIG. 5, with the pressure relief valve spool in a second position;

FIG. 15 is a cross-sectional view taken along line C-C of FIG. 4, with the pressure relief valve spool in a third position;

FIG. 16 is a cross-sectional view B-B of FIG. 5, with the pressure relief valve spool in a third position;

fig. 17 is a schematic three-dimensional view of the valve sleeve of the present invention;

FIG. 18 is a schematic three-dimensional view of a transmission block according to the present invention;

FIGS. 19-20 are schematic views of three-dimensional structures of the diverter valve cartridge of the present invention;

FIGS. 21-22 are schematic three-dimensional structural views of a pressure relief valve cartridge according to the present invention;

FIG. 23 is a schematic three-dimensional view of a control stick according to the present invention;

FIG. 24 is a hydraulic schematic of the present invention;

fig. 25 is a hydraulic schematic diagram of the present invention.

Detailed Description

Referring to fig. 1-25, a damping control valve for an engineering machine includes a valve housing 1, a threaded sleeve 6, and a reversing valve core 2, wherein a reversing valve hole 1a with an opening at the upper end is formed in the valve housing 1, and the threaded sleeve 6 is connected to the upper end of the valve housing 1 in a threaded manner; the reversing valve core 2 is rotatably connected in the reversing valve hole 1a, a transmission block 7 is fixedly installed at the upper end of the reversing valve core 2, and the transmission block 7 is rotatably connected in the reversing valve hole 1 a; the upper end of the valve sleeve 1 is provided with an arc-shaped cutting groove 103 communicated with the reversing valve hole 1a, and the circumferential side surface of the transmission block 7 is provided with a convex column 72 extending into the arc-shaped cutting groove 103; the side surface of the valve sleeve 1 is sequentially provided with an X port, a P port, a T port, a B port and an A port which are communicated with the reversing valve hole 1a from top to bottom, and the lower end of the reversing valve hole 1a in the valve sleeve 1 is provided with an oil hole 1B communicated with the A port; the circumferential side surface of the reversing valve core 2 is provided with a first annular groove 201 communicated with an X port, a second annular groove 202 communicated with a P port and an arc-shaped groove 2031 communicated with a T port; the circumferential side surface of the reversing valve core 2 is provided with a first cutting groove 204 communicated with the second annular groove 202 and a second cutting groove 203 communicated with the arc-shaped groove 2031 along the axial direction; when the convex column 72 is positioned at one end of the arc-shaped cutting groove 103, the reversing valve core 2 is positioned at an initial position, and the port P, the port A, the port B and the port T are not communicated with each other; when the convex column 72 is located at the other end of the arc-shaped cutting groove 103, the reversing valve core 2 rotates, so that the port P is communicated with the port A through the second annular groove 202 and the first cutting groove 204, and the port T is communicated with the port B through the arc-shaped groove 2031 and the second cutting groove 203; a pressure reducing valve piece for controlling the pressure of the port P to be the same as the pressure of the port A is arranged in the reversing valve core 2.

The pressure reducing valve comprises a pressure reducing valve core 3, a control rod 4, an upper spring 5a, a lower spring 5b and a hollow plug 5c, a pressure reducing valve hole 2a with an opening at the upper end is formed in the reversing valve core 2, and the pressure reducing valve core 3 is rotatably connected in the pressure reducing valve hole 2 a; the transmission block 7 is provided with a stud 7a which is in threaded connection with an opening at the upper end of the pressure reducing valve hole 2 a; a through second shaft hole 2b is formed in the middle of the bottom of the pressure reducing valve hole 2a in the reversing valve core 2, a through first shaft hole 2c is formed in the pressure reducing valve core 3, and the first shaft hole 2c and the second shaft hole 2b are coaxially arranged; the upper end of the control rod 4 is connected in the first shaft hole 2c in a sliding manner, and the lower end of the control rod is connected in the second shaft hole 2b in a sliding manner; the inner side wall of the second shaft hole 2b is provided with limiting sliding grooves 2b1 with symmetrical positions along the axial direction, and the side surface of the outer circumference of the control rod 4 is provided with a limiting protrusion 4a which is connected in the limiting sliding grooves 2b1 in a sliding manner; the inner circumferential side wall of the first shaft hole 2c is provided with a spiral groove 2c1, and the outer circumferential side surface of the control rod 4 is provided with a cylinder 4b extending into the spiral groove 2c 1.

A first spring hole 2c2 is arranged at the upper end of the first shaft hole 2c, a second spring hole 2b2 is arranged at the lower end of the second shaft hole 2b, and the hollow plug 5c is arranged at the lower end of the second spring hole 2b 2; the upper spring 5a is positioned in the first spring hole 2c2, the upper end of the upper spring 5a abuts against the stud 7a, and the lower end abuts against the lower end of the first spring hole 2c2 through the hollow lower gasket 41; the lower spring 5b is positioned in the second spring hole 2b2, the lower end of the lower spring abuts against the hollow plug 5c, and the upper end of the lower spring abuts against the upper end of the second spring hole 2b2 through the hollow upper gasket 42; a first through hole 21 for communicating the first annular groove 201 with the pressure reducing valve hole 2a, a second through hole 22 for communicating the second annular groove with the pressure reducing valve hole 2a, and a third through hole 23 for communicating the arc-shaped groove 2031 with the pressure reducing valve hole 2a are arranged in the reversing valve core 2; the side surface of the outer circumference of the pressure reducing valve core 3 is provided with a third annular groove 301 communicated with the second through hole 22, the side surface of the circumference of the pressure reducing valve core 3 is provided with a third cutting groove 33 communicated with the third annular groove 301 along the axial direction thereof downwards, and a fourth cutting groove 32 and a fifth cutting groove 31 communicated with the third annular groove 301 are upwards arranged; a sixth notch 38 for communicating the fifth notch 31 with the first spring hole 2c2 is provided in the pressure reducing valve body 3; when the pressure of the port A is equal to the pressure of the port P, the pressure reducing valve core 3 is in the first position, and the port P, the port T and the port X are not communicated with each other; when the pressure of the port A is higher than that of the port P, the pressure reducing valve core 3 is in a third position, and the port P is communicated with the port X through the second annular groove 202, the second through hole 22, the third annular groove 301, the fourth cutting groove 32, the first through hole 21 and the first annular groove; when the pressure of the port a is lower than that of the port P, the pressure reducing valve core 3 is in the second position, and the port P is communicated with the port T through the second annular groove 202, the second through hole 22, the third annular groove 301, the third cutting groove 33, the third through hole 23 and the arc-shaped groove 2031.

The upper end of transmission piece 7 is equipped with the pivot 7b of rotation connection in swivel nut 6, fixed mounting has the output shaft to pass through pin key and pivot 7b fixed connection's step motor 10 on the swivel nut 6, step motor 10 is used for rotating through pivot 7b drive transmission piece 7. A first positioning groove 101 and a second positioning groove 102 are arranged on the inner side wall of the reversing valve hole 1a at positions close to the upper end, a mounting hole 7c is radially arranged on the outer circumferential side surface of the transmission block 7, and a positioning steel ball 9 and a positioning spring 8 for forcing the positioning steel ball 9 to press the inner side wall of the reversing valve hole 1a are arranged in the mounting hole 7 c; as shown in fig. 8, when the convex column 72 is located at one end of the arc-shaped slot 103, the positioning steel ball 9 is pressed in the first positioning groove 101 under the action of the positioning spring 8; when the convex column 72 is positioned at the other end of the arc-shaped slot 103, the positioning steel ball 9 is pressed in the second positioning slot 102 under the action of the positioning spring 8, as shown in fig. 10. The upper end of the reversing valve hole 1a is provided with a torsion spring 11 which is sleeved at the upper end of the transmission block 7, and the torsion spring 11 is used for forcing the convex column 72 to move towards one end of the arc-shaped cutting groove 103.

In use, as shown in the hydraulic circuit of fig. 24, the port X of the present invention is communicated with the outlet of the hydraulic pump 13, the port a is communicated with the rodless chamber of the boom cylinder 17, the port B is communicated with the rod chamber of the boom cylinder 17, the port T is communicated with the oil tank 15, and the port P is communicated with the port of the accumulator 14.

The specific functional process of the invention is as follows:

liquid filling stage: when the engineering machinery does not need vibration reduction in normal operation, when the stepping motor 10 is in a zero position, the convex column 72 is positioned at one end of the arc-shaped cutting groove 103 under the acting force of the torsion spring 11, the reversing valve core 2 is in an initial position, the positioning steel ball 9 is positioned in the first positioning groove 101 (shown in fig. 7 and 8), and the port P, the port A, the port B and the port T are not communicated with each other at the moment as shown in fig. 7; the port (i.e., port P) of the accumulator 14 is isolated from port A, and port B is isolated from port T. If the pressure of the port A is greater than that of the port P, the control rod 4 is located at the position shown in fig. 15 and 16 under the action of the pressure difference, the pressure reducing valve core 3 is located at the third position, the port P is communicated with the port X through the second annular groove 202, the second through hole 22, the third annular groove 301, the fourth cutting groove 32, the first through hole 21 and the first annular groove, at this time, the hydraulic pump 13 charges the accumulator 14 with hydraulic fluid, meanwhile, the hydraulic pressure of the port P enters the first spring hole 2c2 through the fifth cutting groove 31 and the sixth cutting groove 38, and acts on the upper end of the control rod 4 to push the control rod 4 to move downwards, and due to the matching of the limiting protrusion 4a and the limiting sliding groove 2b1 and the matching of the cylinder 4b and the spiral groove 2c1, the pressure reducing valve core 3 is driven to rotate when the control rod 4 moves downwards until the pressure of the port A is equal to the pressure of the port P, and. If the pressure of the port a is lower than that of the port P, the control rod 44 is at the position shown in fig. 13 and 14 under the action of the pressure difference, the pressure reducing valve core 3 is at the second position, the port P is communicated with the port T through the second annular groove 202, the second through hole 22, the third annular groove 301, the third cutting groove 33, the third through hole 23 and the arc-shaped groove 2031, at this time, the accumulator 14 overflows to the port T, meanwhile, as the pressure of the oil in the accumulator 14 (i.e., the port P) decreases, the pressure of the oil at the port a enters the second spring hole 2b2 through the oil hole 1b and the hollow plug 5c, and acts on the lower end of the control rod 4 to push the control rod 4 upward, due to the matching of the limit protrusion 4a and the limit sliding groove 2b1, and the matching of the cylinder 4b and the spiral groove 2c1, when the control rod 4 moves upwards, the pressure reducing valve core 3 is driven to rotate until the pressure at the port A is equal to the pressure at the port P, and the pressure reducing valve core 3 rotates to the first position.

A vibration reduction stage: when the engineering machinery runs at a high speed, the stepping motor 10 is controlled to rotate forwards, and then the transmission block 7 is driven to rotate through the rotating shaft 7B, so that the convex column 72 is positioned at the other end of the arc-shaped cutting groove 103, then the stepping motor 10 is controlled to lose power, at the moment, under the action of the reversing valve core 2, an interface (namely a port P) of the energy accumulator 14 is communicated with a port A, a port B is communicated with a port T, namely, a rodless cavity of the movable arm oil cylinder 17 is communicated with the energy accumulator 14, a rod cavity of the movable arm oil cylinder 17 is communicated with the oil tank 15, and at the moment that the energy accumulator 14 is communicated with the rodless cavity of the movable arm oil cylinder 17, due to the fact that the pressure in the energy accumulator 14 is equal to the pressure in the rodless. When the movable arm moves up and down along with the change of road conditions, when the movable arm moves up, oil in the energy accumulator 14 fills a rodless cavity of the movable arm oil cylinder 17 to jack the movable arm oil cylinder 17, and the oil in a rod cavity of the movable arm oil cylinder 17 returns to the oil tank 15 from a port B through a port T; when the boom cylinder 17 moves downward, the oil in the rodless chamber of the boom cylinder 17 flows into the accumulator 14, and the oil in the oil tank 15 flows into the rod chamber of the boom cylinder 17, thereby achieving a state similar to floating during traveling and achieving a vibration damping function. When the engineering machinery returns to normal operation from high-speed running, the stepping motor 10 is controlled to rotate reversely, and under the action of the torsion spring 11, the convex column 72 on the transmission block 7 moves from the other end of the arc-shaped cutting groove 103 to one end thereof, so as to drive the reversing valve core 2 to return to the initial position.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The engineering machinery vibration reduction control valve is characterized by comprising a valve sleeve, a threaded sleeve and a reversing valve core, wherein a reversing valve hole with an opening at the upper end is formed in the valve sleeve, and the threaded sleeve is in threaded connection with the upper end of the valve sleeve; the reversing valve core is rotatably connected in the reversing valve hole, a transmission block is fixedly mounted at the upper end of the reversing valve core, and the transmission block is rotatably connected in the reversing valve hole; the upper end of the valve sleeve is provided with an arc-shaped cutting groove communicated with the reversing valve hole, and the circumferential side surface of the transmission block is provided with a convex column extending into the arc-shaped cutting groove; the side surface of the valve sleeve is sequentially provided with an X port, a P port, a T port, a B port and an A port which are communicated with the reversing valve hole from top to bottom, and the lower end of the reversing valve hole in the valve sleeve is provided with an oil hole communicated with the A port; the circumferential side surface of the reversing valve core is provided with a first annular groove communicated with the X port, a second annular groove communicated with the P port and an arc-shaped groove communicated with the T port; a first cutting groove communicated with the second annular groove and a second cutting groove communicated with the arc-shaped groove are formed in the circumferential side surface of the reversing valve core along the axial direction of the reversing valve core; when the convex column is positioned at one end of the arc-shaped cutting groove, the reversing valve core is positioned at an initial position, and the port P, the port A, the port B and the port T are not communicated with each other; when the convex column is positioned at the other end of the arc-shaped cutting groove, the reversing valve core rotates to enable the port P to be communicated with the port A through the second annular groove and the first cutting groove, and the port T is communicated with the port B through the arc-shaped groove and the second cutting groove; and a pressure reducing valve piece for controlling the pressure of the port P to be the same as that of the port A is arranged in the reversing valve core.

2. The engineering machinery vibration damping control valve according to claim 1, wherein the pressure reducing valve member comprises a pressure reducing valve core, a control rod, an upper spring, a lower spring and a hollow plug, a pressure reducing valve hole with an open upper end is formed in the reversing valve core, and the pressure reducing valve core is rotatably connected in the pressure reducing valve hole; the transmission block is provided with a stud which is in threaded connection with an opening at the upper end of the pressure reducing valve hole; a second shaft hole which penetrates through the reversing valve core is arranged in the middle position of the bottom of the pressure reducing valve hole in the reversing valve core, a first shaft hole which penetrates through the reversing valve core is arranged in the pressure reducing valve core, and the first shaft hole and the second shaft hole are coaxially arranged; the upper end of the control rod is connected in the first shaft hole in a sliding manner, and the lower end of the control rod is connected in the second shaft hole in a sliding manner; the inner side wall of the second shaft hole is provided with limiting sliding grooves which are symmetrical in position along the axial direction of the inner side wall, and the outer circumferential side surface of the control rod is provided with a limiting bulge which is connected in the limiting sliding grooves in a sliding manner; the side wall of the inner circumference of the first shaft hole is provided with a spiral groove, and the side surface of the outer circumference of the control rod is provided with a cylinder extending into the spiral groove;

3. The damping control valve for engineering machinery according to claim 1, wherein a rotating shaft rotatably connected in a threaded sleeve is arranged at the upper end of the transmission block, a stepping motor with an output shaft fixedly connected with the rotating shaft is fixedly mounted on the threaded sleeve, and the stepping motor is used for driving the transmission block to rotate through the rotating shaft.

4. The damping control valve for engineering machinery according to claim 1, wherein a first positioning groove and a second positioning groove are formed in the inner side wall of the reversing valve hole at positions close to the upper end, a mounting hole is radially formed in the outer circumferential side surface of the transmission block, a positioning steel ball and a positioning spring for forcing the positioning steel ball to press towards the inner side wall of the reversing valve hole are arranged in the mounting hole; when the convex column is positioned at one end of the arc-shaped cutting groove, the positioning steel ball is pressed in the first positioning groove under the action of the positioning spring; when the convex column is positioned at the other end of the arc-shaped cutting groove, the positioning steel ball is pressed in the second positioning groove under the action of the positioning spring.

5. The damping control valve for construction machinery as claimed in claim 1, wherein the upper end of the reversing valve hole is provided with a torsion spring sleeved on the upper end of the transmission block, and the torsion spring is used for forcing the convex column to move towards one end of the arc-shaped slot.