CN108591177B

CN108591177B - Rotation buffering device, rotation control system and engineering machinery

Info

Publication number: CN108591177B
Application number: CN201810767451.6A
Authority: CN
Inventors: 胡小冬; 周彬; 朱双双
Original assignee: Xuzhou Heavy Machinery Co Ltd
Current assignee: Xuzhou Heavy Machinery Co Ltd
Priority date: 2018-07-13
Filing date: 2018-07-13
Publication date: 2020-02-21
Anticipated expiration: 2038-07-13
Also published as: CN108591177A

Abstract

The invention relates to the technical field of engineering machinery, in particular to a rotation buffer device, a rotation control system and engineering machinery. The invention provides a rotary buffering device, which comprises a load-sensing buffering valve, wherein the load-sensing buffering valve comprises a valve cavity, a first oil port, a second oil port, a valve core and a spring, the first oil port guides one of a first working oil port and a second working oil port of a rotary motor of engineering machinery with larger pressure to act on a second end, opposite to a first end, abutted against the spring, of the valve core, a buffering structure is arranged on the valve core, the first oil port is communicated with the second oil port through the buffering structure in the process that the valve core moves along the direction from the second end to the first end, and the flow area of the buffering structure is gradually increased. In the invention, the load sensing buffer valve can sense the load pressure and provide different buffer resistances which are positively correlated with the load pressure, so that the buffer requirements of different load working conditions can be better adapted, and a better buffer effect is realized.

Description

Rotation buffering device, rotation control system and engineering machinery

Technical Field

The invention relates to the technical field of engineering machinery, in particular to a rotation buffer device, a rotation control system and engineering machinery.

Background

The crane and other engineering machinery can make rotary motion relative to the chassis, and the start-stop stability of the rotary process is an important index of the performance of the whole machine.

At present, a rotation buffer device is usually arranged in a rotation control system, and the oil return speed of a rotation motor in the rotation starting and stopping process is controlled, so that the inertia impact in the rotation starting and stopping process is reduced, and the starting and stopping stability is improved. However, in the rotary buffering device in the prior art, the buffering capacity of the rotary buffering device generally cannot be changed along with different loads, the rotary buffering device is difficult to adapt to buffering requirements of different load working conditions, and the buffering effect is poor.

Disclosure of Invention

The invention aims to solve the technical problems that: the buffering effect of the rotary buffering device is improved.

In order to solve the above technical problem, a first aspect of the present invention provides a slewing damping device, including:

a load-sensing trim valve comprising:

a valve cavity;

the first oil port is communicated with the valve cavity;

the second oil port is communicated with the valve cavity and is used for being communicated with an oil tank;

the valve core is movably arranged in the valve cavity and controls the connection and disconnection between the first oil port and the second oil port by moving in the valve cavity; and the combination of (a) and (b),

the spring is arranged in the valve cavity and abuts against the first end of the valve core;

wherein:

the first oil port guides one of a first working oil port and a second working oil port of a rotary motor of the engineering machinery, which has larger pressure, to act on a second end, opposite to the first end, of the valve core;

and, be equipped with buffer structure on the case, at the in-process that the case removed along the direction from second end to first end, first hydraulic fluid port passes through buffer structure and second hydraulic fluid port intercommunication, and buffer structure's through-flow area grow gradually.

Optionally, the buffer structure comprises a choke, wherein: the throttle area of the throttle orifices is gradually reduced along the direction from the second end to the first end, and/or the number of the throttle orifices is at least two, and the at least two throttle orifices are arranged at intervals along the direction from the second end to the first end.

Optionally, the number of the throttling ports is at least two, a middle flow passage is further arranged on the valve core, and the first oil port is communicated with the at least two throttling ports through the middle flow passage.

Optionally, the rotary buffering device further includes a first pressure selecting mechanism, and the first pressure selecting mechanism is communicated with the first oil port and controls the first oil port to be communicated with one of the first working oil port and the second working oil port of the rotary motor, which has a larger pressure.

Optionally, the first pressure selection mechanism includes a first shuttle valve, an outlet of the first shuttle valve is communicated with the first oil port, and two inlets of the first shuttle valve are respectively communicated with the first working oil port and the second working oil port of the rotary motor; or the first pressure selection mechanism comprises a first one-way valve and a second one-way valve, an inlet of the first one-way valve is communicated with a first working oil port of the rotary motor, an inlet of the second one-way valve is communicated with a second working oil port of the rotary motor, and an outlet of the first one-way valve and an outlet of the second one-way valve are communicated with the first oil port.

Optionally, the effective pressure acting area of the first end is greater than the effective pressure acting area of the second end.

Optionally, the load sensing cushion valve further comprises an elasticity adjusting part, and the elasticity adjusting part adjusts the elastic force of the spring by adjusting the deformation amount of the spring.

Optionally, the rotary buffering device further comprises a reversing valve, the reversing valve is provided with a pilot oil port, and the pilot oil port controls one of a first working oil port and a second working oil port of the rotary motor to be communicated with the oil source and the other to be communicated with the oil tank by controlling the reversing valve to reverse; and the load sensing buffer valve also comprises a third oil port which is communicated with the valve cavity where the pilot oil port and the spring are located.

Optionally, the pilot oil port comprises a first pilot oil port and a second pilot oil port, the first pilot oil port controls the reversing valve to reverse between the middle position and the left position, and the second pilot oil port controls the reversing valve to reverse between the middle position and the right position; the third oil port is communicated with the valve cavity where the spring is located and one of the first pilot oil port and the second pilot oil port, which has higher pressure.

Optionally, the rotary buffering device further includes a second pressure selection mechanism, and the third oil port is communicated with one of the first pilot oil port and the second pilot oil port, which has a larger pressure, through the second pressure selection mechanism.

Optionally, the second pressure selection mechanism includes a second shuttle valve, an outlet of the second shuttle valve is communicated with the third oil port, and two inlets of the second shuttle valve are respectively communicated with the first pilot oil port and the second pilot oil port; or the second pressure selection mechanism comprises a third one-way valve and a fourth one-way valve, an inlet of the third one-way valve is communicated with the first pilot oil port, an inlet of the fourth one-way valve is communicated with the second pilot oil port, and an outlet of the third one-way valve and an outlet of the fourth one-way valve are communicated with the third oil port.

Optionally, the valve chamber in which the spring is located is adapted to communicate with the fuel tank.

Optionally, the valve cavity in which the spring is located is communicated with the second oil port, so that the valve cavity in which the spring is located is communicated with the oil tank through the second oil port.

Optionally, an auxiliary flow passage is further arranged on the valve core, and the auxiliary flow passage communicates the valve cavity where the spring is located and the second oil port.

The second aspect of the invention also provides a rotation control system, which comprises a rotation motor and the rotation buffer device of the invention, wherein the first pressure selection mechanism of the rotation buffer device controls the first oil port to be communicated with one of the first working oil port and the second working oil port of the rotation motor, which has larger pressure.

The third aspect of the invention also provides engineering machinery comprising the rotary control system.

In the invention, the load sensing buffer valve is set to have a buffer structure with the flow area capable of being in positive correlation change along with the load, so that the load sensing buffer valve can sense the load pressure and provide different buffer resistances in positive correlation with the load pressure, the buffer requirements of different load working conditions can be better adapted, and a better buffer effect is realized.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 shows a hydraulic schematic of a slewing damping device according to a first embodiment of the invention.

FIG. 2 shows a hydraulic schematic of the load-sensing trim valve of FIG. 1.

FIG. 3 illustrates a cross-sectional schematic view of the load sensing trim valve of FIGS. 1 and 2.

Fig. 4 shows a hydraulic schematic of a slewing damping device according to a second embodiment of the invention.

FIG. 5 illustrates a hydraulic schematic of the load sensing trim valve of FIG. 4.

FIG. 6 illustrates a cross-sectional structural view of the load sensing trim valve of FIGS. 4 and 5.

Fig. 7 shows a schematic cross-sectional view of a load sensing trim valve in a third embodiment of the present invention.

Fig. 8 shows a schematic cross-sectional view of a load sensing trim valve in a fourth embodiment of the present invention.

In the figure:

1. a diverter valve; 2. a load sensing cushion valve; 3. a first shuttle valve; 4. a second shuttle valve;

21. a valve body; 22. a valve core; 23. a spring; 24. an elasticity adjusting member;

221. a choke; 222. an auxiliary flow passage; 223. an intermediate flow passage;

I. a valve cavity; A. a first oil port; B. a second oil port; C. a third oil port; D. a first working oil port; E. a second working oil port; a. a first pilot oil port; b. a second pilot oil port; t, an oil tank connector; p and an oil source connecting port.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present invention.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In the description of the present invention, it is to be understood that the orientation or positional relationship indicated by the orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc. are usually based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and in the case of not making a reverse description, these orientation words do not indicate and imply that the device or element being referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore, should not be considered as limiting the scope of the present invention; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

In the description of the present invention, it should be understood that the terms "first", "second", etc. are used to define the components, and are used only for the convenience of distinguishing the corresponding components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present invention.

Fig. 1-8 show four embodiments of the slew damping apparatus of the present invention. Referring to fig. 1 to 8, the rotary damping device provided by the present invention includes a load sensing damper valve 2, the load sensing damper valve 2 includes a valve cavity I, a first oil port a, a second oil port B, a valve core 22 and a spring 23, wherein the valve core 22 and the spring 23 are both disposed in the valve cavity I, the spring 23 is disposed at a first end of the valve core 22 in a propping manner, the first oil port a and the second oil port B are both communicated with the valve cavity I, the second oil port B is used for being communicated with an oil tank, the first oil port a guides one of a first working oil port D and a second working oil port E of a rotary motor of an engineering machine with a larger pressure to act on a second end of the valve core 22 opposite to the first end, the valve core 22 is movably disposed in the valve cavity I and controls the on-off state between the first oil port a and the second oil port B by moving in the valve cavity I, the valve core 22 is provided with a damping structure, and in the process that the valve core 22 moves, the first oil port A is communicated with the second oil port B through the buffering structure, and the through flow area of the buffering structure is gradually increased.

According to the rotary buffering device, the valve core 22 of the load sensing buffering valve 2 senses a load through the first oil port A, the first oil port A and the first oil port B are communicated to release pressure through moving along the direction from the second end to the first end under the action of the load, the flow area of the buffering structure on the valve core 22 is gradually increased along with the movement of the valve core 22 along the direction from the second end to the first end, and therefore the flow area of the buffering structure is positively correlated with the load, the rotary buffering device can correspondingly increase or decrease the buffer resistance of the rotary buffering device according to the increase or decrease of the load, the buffering effect is effectively improved, and the stability of starting and stopping of rotation is improved.

In addition, the first oil port a of the present invention can directly guide the load pressure to act on the second end of the valve core 22, and does not need to read the operation parameters such as the arm length and the weight of the crane, etc. to detect the load pressure, and also does not need to perform intermediate conversion such as an electrical signal, etc., so that the load pressure can be obtained more conveniently, efficiently and accurately, the load pressure can be reflected more truly, and further, the buffer resistance and the load pressure can be more reliably matched, and a more effective buffer process can be realized.

In the present invention, in order to make the flow area of the damping structure gradually larger in the process of the spool 22 moving in the direction from the second end to the first end, the damping structure may be configured such that: the buffer structure comprises a choke 221, wherein: the throttle area of the throttle orifice 221 decreases gradually in the direction from the second end to the first end, and/or the number of the throttle orifices 221 is at least two, and the at least two throttle orifices 221 are arranged at intervals from each other in the direction from the second end to the first end. Based on this, the buffer structure is the throttle structure, and it realizes the buffering through throttling load hydraulic oil, and the throttle opening of buffer structure becomes progressively at the in-process that case 22 removed (namely opened the pressure release) along the direction from second end to first end for in the in-process that case 22 opened the pressure release, the through-flow area of buffer structure can increase gradually, thereby increases the buffer resistance nature of buffer structure gradually.

Wherein, it is possible to set the buffer structure to include only one throttle 221, and set the throttle 221 such that the throttle area gradually decreases along the direction from the second end to the first end, so that the desired change of the flow area of the buffer structure is realized only by the change of the throttle area of the throttle 221; it is also possible to provide that the damping structure comprises at least two chokes 221 and to arrange the at least two chokes 221 as discrete, such that the desired change of the flow area of the damping structure is achieved only by a change of the number and/or position of the chokes 221; alternatively, it may also be provided that the damping structure comprises at least two chokes 221, and that the choke area of some or all of the at least two chokes 221 is gradually reduced in the direction from the second end to the first end, so that the desired change of the flow area of the damping structure may be achieved by a change of the choke area of the chokes 221 and a change of the number and/or position of the chokes 221 at the same time.

In order to facilitate the first port a to guide the hydraulic oil with the larger pressure of the first working port D and the second working port E of the rotary motor to the second end of the valve core 22, the rotary buffering device of the invention may further include a first pressure selecting mechanism, which is communicated with the first port a and controls the first port a to be communicated with the larger pressure of the first working port D and the second working port E of the rotary motor. Through setting up first pressure selection mechanism, can be automatically with the great one of pressure and first hydraulic fluid port A intercommunication in the first work hydraulic fluid port D of rotary motor and the second work hydraulic fluid port E, make the great one of pressure in the first work hydraulic fluid port D and the second work hydraulic fluid port E that act on the rotary motor always through first hydraulic fluid port A second end more reliably, realize that case 22 is more convenient, high-efficient and respond to load pressure reliably.

In addition, in order to further ensure that the valve core 22 can be opened under the action of load pressure when buffering is needed, the valve cavity I (also commonly referred to as a spring cavity) where the spring 23 is located can be set to be communicated with a fuel tank. Through with spring chamber and oil tank intercommunication, can realize the pressure release to the spring chamber, reduce the oil pressure in spring chamber, make when needs buffering, the elastic force that spring 23 was applyed to case 22 almost only need be overcome to the load, can push case 22 and remove and open, implement cushioning effect, prevent because of spring intracavity pressure is too big, lead to the unable case 22 of pushing of load to open, the phenomenon that can't implement cushioning effect appears, consequently, can effectively improve the reliability that the load pushed case 22 and removed and open when needing the buffering. Wherein, the intercommunication of spring chamber and oil tank both can be realized through directly communicating the spring chamber with the oil tank, also can realize through communicating spring chamber and second hydraulic fluid port B, and the latter is owing to can directly utilize the second hydraulic fluid port B that communicates with the oil tank of load induction cushion valve 2, consequently, the structure is simpler, and the processing of being more convenient for is realized.

On the other hand, in order to reduce the influence of the load sensing cushion valve 2 on the normal rotation process, the invention also provides a corresponding improved embodiment.

As one of them, the present invention may arrange the spool 22 such that the effective pressure acting area of the first end thereof is larger than that of the second end thereof. Based on the embodiment, a certain effective pressure acting area difference exists at the two ends of the valve core 22, and the effective pressure acting area at the spring side is larger than that at the buffering structure side, which is beneficial to making the acting force of the load on the second end of the valve core 22 smaller than the acting force of the spring 23 (or the spring 23 and the spring cavity hydraulic oil) on the first end of the valve core 22 in the normal rotation process, thereby being beneficial to making the valve core 22 reliably locked in the normal rotation process, preventing the valve core 22 from being opened for buffering to influence the normal rotation speed, and realizing the safer and more reliable normal rotation working process.

As another one of them, the present invention may also provide the slewing damping device as: the rotary buffering device also comprises a reversing valve 1, wherein the reversing valve 1 is provided with a pilot oil port, and the pilot oil port controls one of a first working oil port D and a second working oil port E of the rotary motor to be communicated with an oil source and the other to be communicated with an oil tank by controlling the reversing valve 1 to reverse; and the load sensing cushion valve 2 further comprises a third oil port C, and the third oil port C is communicated with the pilot oil port and a valve cavity I (i.e. a spring cavity) where the spring 23 is located. In this embodiment, the spring cavity is communicated with the pilot oil port of the directional valve 1, which not only enables the load sensing cushion valve 2 to sense the rotation working state, but also enables the spring 23 to apply an acting force to the first end of the spool 22 on one side of the spring cavity, and simultaneously the pilot oil of the directional valve 1 also applies an acting force to the first end of the spool 22, and compared with the case that only the spring 23 applies an acting force to the first end of the spool 22, the acting force applied to the first end of the spool 22 can be effectively increased, that is, the opening pressure of the spool 22 can be effectively increased, so that the spool 22 can be more reliably locked in the normal rotation process, and the risk that the normal rotation speed is affected by the buffering effect can be more effectively reduced.

Of course, as another alternative, the present invention may also set the valve core 22 such that the effective pressure acting area of the first end of the valve core is larger than that of the second end of the valve core, and set the third oil port C on the load sensing cushion valve 2 to communicate the pilot oil port of the directional valve 1 and the spring cavity, so as to more fully reduce the influence of the load sensing cushion valve 2 on the normal rotation process, and to realize the normal rotation process more safely and reliably.

The invention will be further described in connection with four embodiments shown in fig. 1-8.

First, the description will be given with reference to the first embodiment shown in fig. 1 to 3.

As shown in fig. 1-3, in this first embodiment, the swing control system includes a directional valve 1, a load sense trim valve 2, a first shuttle valve 3, and a second shuttle valve 4.

The reversing valve 1 is used for controlling a rotation working state, namely whether the upper vehicle of the engineering machinery rotates relative to the chassis or not and the rotation direction of the upper vehicle relative to the chassis.

As can be seen from fig. 1, in this embodiment, the reversing valve 1 adopts a three-position six-way valve structure, which has six ports, namely a first port, a second port, a third port, a fourth port, a fifth port and a sixth port, and has three valve positions, namely a middle position, a left position and a right position, wherein, the first valve port is communicated with an oil source connecting port P communicated with an oil source, the second valve port is communicated with an oil tank connecting port T communicated with an oil tank, the third valve port is communicated with a first working oil port D of the rotary motor, the fourth valve port is communicated with a second working oil port E of the rotary motor, and when the valve is in the middle position, the first valve port, the second valve port, the third valve port and the fourth valve port are all cut off, are not communicated with each other and are in a disconnected state, the fifth valve port is communicated with the sixth valve port, the fifth valve port is communicated with the oil source connecting port P, and the sixth valve port is communicated with the oil tank connecting port T (specifically, the sixth valve port is communicated with the oil tank connecting port I through two check valves which are connected in parallel and arranged in reverse direction); when the valve is in the left position, the first valve port is communicated with the third valve port (specifically, the one-way communication is carried out along the direction from the first valve port to the third valve port), the second valve port is communicated with the fourth valve port (specifically, the one-way communication is carried out along the direction from the fourth valve port to the second valve port), and the fifth valve port and the sixth valve port are both closed; when the valve is in the right position, the first valve port is communicated with the fourth valve port (specifically, in one-way communication along the direction from the first valve port to the fourth valve port), the second valve port is communicated with the third valve port (specifically, in one-way communication along the direction from the third valve port to the second valve port), and the fifth valve port and the sixth valve port are both closed.

Based on the arrangement, when the reversing valve 1 is in the middle position, the first working oil port D and the second working oil port E are not communicated with an oil source or an oil tank, the rotary motor does not work, the upper vehicle does not rotate relative to the chassis, meanwhile, hydraulic oil provided by the oil source can flow back to the oil tank through the oil source connecting port P, the sixth valve port, the fifth valve port and the oil tank connecting port T, in the process, two check valves which are connected in parallel and reversely arranged on an oil path connecting the sixth valve port and the oil tank connecting port T can provide oil return back pressure, oil diversion of the oil tank is avoided, and air suction is prevented; when the hydraulic lifting device is positioned at a left position, the reversing valve 1 controls the first working oil port D to be communicated with an oil source through the oil source connecting port P, and the second working oil port E is communicated with an oil tank through the oil tank connecting port T, so that the rotary motor rotates along a first direction, and the upper vehicle can rotate towards one direction relative to the chassis; when the steering valve 1 is in the right position, the second working oil port E is controlled by the steering valve 1 to be communicated with an oil source through the oil source connecting port P, and the first working oil port D is communicated with an oil tank through the oil tank connecting port T, so that the rotary motor rotates along a second direction opposite to the first direction, and the turning of the upper vehicle relative to the chassis to the other direction is realized.

It can be seen that the reversing valve 1 can control whether the first working oil port D and the second working oil port E are communicated with the oil source and the oil tank and specifically communicated with the oil source and the oil tank through reversing, wherein when the reversing valve 1 is switched to the left position or the right position from the middle position, one of the first working oil port D and the second working oil port E is communicated with the oil source and the other is communicated with the oil tank, the engineering machine is in the normal rotation working process, and when the reversing valve 1 is switched to the middle position from the left position or the right position, the first working oil port D and the second working oil port E are both not communicated with the oil source and the oil tank, and the engineering machine is in the rotation stopping process.

Of course, it should be understood by those skilled in the art that the directional valve 1 is not limited to the three-position six-way directional valve structure shown in fig. 1, and for example, it may be arranged in a non-one-way communication manner between the valve ports that communicate with each other in the left or right position, or may be in other structures besides three-position six-way.

In order to control the reversing valve 1 to reverse, as shown in fig. 1, the reversing valve 1 of this embodiment further includes a pilot oil port, and in this embodiment, the pilot oil port includes a first pilot oil port a and a second pilot oil port b, where the first pilot oil port a is disposed on one side of the left position and is used for controlling the reversing valve 1 to switch between the middle position and the left position; and the second pilot oil port b is arranged on one side of the right position and used for controlling the reversing valve 1 to switch between the middle position and the right position. Through setting up first leading hydraulic fluid port a and second leading hydraulic fluid port b, can automatic control switching-over valve 1 commutate between meso position, left position and right position, the switching-over is convenient more accurate, and efficiency is higher.

The load sensing buffer valve 2 is used for buffering according to the load, so that the whole machine shaking caused by inertia impact in the process of turning on and off is reduced, and the stability of turning on and off is improved. As can be seen from fig. 1 to 3, the load-sensing cushion valve 2 of this embodiment is a spool valve that includes a valve body 21, a spool 22, a spring 23, and a spring force adjusting member 24.

The valve body 21 provides a mounting base for the valve core 22, the spring 23, the elastic force adjusting component 24 and the like, and cooperates with the valve core 22, the spring 23, the elastic force adjusting component 24 and the like to realize a required buffering function. As shown in fig. 3, in this embodiment, a valve cavity I is opened on the valve body 21, and the valve cavity I includes a first chamber (i.e., a left chamber in fig. 3), a second chamber (i.e., a middle chamber in fig. 3), and a third chamber (i.e., a right chamber in fig. 3) which are sequentially communicated, wherein an inner diameter of the first chamber is smaller than an inner diameter of the second chamber but larger than an inner diameter of the third chamber. Meanwhile, the valve body 21 is further provided with a first oil port a, a second oil port B and a third oil port C, and as can be seen from fig. 1 and 3, in this embodiment, the first oil port a is communicated with the third chamber and is communicated with one of the first working oil port D and the second oil port E, which has a larger pressure, through the first shuttle valve 3; the second oil port B is communicated with the second chamber and is communicated with an oil tank through an oil tank connecting port T; the third port C is communicated with the first chamber and is communicated with one of the first pilot port a and the second pilot port b, which has a larger pressure, through the second shuttle valve 4. Based on this, the first port a may direct the load pressure to the third chamber so that the load sensing cushion valve 2 may sense the load; the third chamber C can lead the pilot pressure of the reversing valve 1 to the first chamber, so that the load sensing buffer valve 2 can sense which rotation state the engineering machinery is in; and, through whether control third chamber communicates with the second chamber, can control whether to lead load fluid back to the oil tank, whether carry out the pressure release to the load promptly.

The valve core 22 is movably disposed in the valve cavity I, and is used for controlling the connection and disconnection between the first oil port a and the second oil port B by sliding in the valve cavity I, so as to control whether to perform rotation buffering. In this embodiment, the valve core 22 controls whether the first port a and the second port B are communicated and whether the swing buffering is performed by controlling whether the third chamber and the second chamber are communicated through the buffering structure.

Specifically, as shown in fig. 3, the valve core 22 of this embodiment includes a first valve core portion, a second valve core portion and a third valve core portion, which are connected in sequence, wherein the radial dimensions of the first valve core portion and the third valve core portion are respectively adapted to the inner diameter of the first chamber and the inner diameter of the third chamber, one end of the first valve core portion (the left end of the first valve core portion in fig. 3) far away from the third valve core portion forms a first end of the valve core 22, one end of the third valve core portion (the right end of the third valve core portion in fig. 3) far away from the first valve core portion forms a second end of the valve core 22, and the first valve core portion and the third valve core portion are respectively in sliding fit with the inner wall of the first chamber and the inner wall of the third chamber; a second valve core connected between the first spool portion and the third valve core is located in the second chamber and has a smaller radial dimension than the first spool portion and the third valve core. Because the inner diameter of the first chamber is larger than the inner diameter of the third chamber, and the radial size of the first valve core part and the radial size of the third valve core part are respectively matched with the inner diameter of the first chamber and the inner diameter of the third chamber, the inner diameter of the first valve core part is larger than the inner diameter of the third valve core part, and the cross-sectional area of the first valve core part is larger than the cross-sectional area of the third valve core part, so that the effective pressure acting area of the first valve core part is larger than that of the third valve core part, namely, the effective pressure acting area of the first end of the valve core 22 is larger than that of the second end of the valve core 22.

As can be seen from fig. 3, in this embodiment, the valve body 22 is provided with one orifice 221 serving as a cushion structure, and the orifice 221 communicates the third chamber and the second chamber with an increasing orifice area as the valve body 22 moves from the second end to the first end (i.e., in the direction from right to left in fig. 3). More specifically, as shown in fig. 3, the throttle orifice 221 of this embodiment is a gradual throttle groove, the throttle area of which gradually decreases in the direction from the second end to the first end (or, stated otherwise, the throttle area of which gradually increases in the direction from the first end to the second end), and which is provided on the circumferential surface of the third valve core and extends from the end of the third valve core that is away from the first valve core portion (i.e., the second end of the valve spool 22) toward the end of the third valve core that is close to the first valve core portion.

Based on the above arrangement, a throttling channel (resistive channel) is formed between the throttling port 221 and the inner wall of the valve body 21, when the throttling channel is opened, the first oil port a and the second oil port B are communicated, and the start-stop pressure can be released smoothly under the throttling action of the throttling channel, so that the buffering effect is realized. In addition, in this embodiment, the valve core 22 is controlled to move along the direction from the second end to the first end, so that the third chamber and the second chamber can be controlled to be communicated through the throttle orifice 221, that is, the valve core 22 is controlled to be communicated with the third chamber and the second chamber, so that the first oil port a communicated with the third chamber and the second oil port B communicated with the second chamber are communicated, and further the load oil liquid communicated with the first oil port a and the oil tank communicated with the second oil port B are communicated, so that the load oil liquid entering the first oil port a can flow back to the oil tank through the third chamber, the throttle orifice 221, the second chamber and the second oil port B, and the pressure relief of the load oil liquid is realized. In this process, since the throttle area of the throttle orifice 221 is gradually changed and gradually decreases in the direction from the second end to the first end, the opening degree of the throttle orifice 221 gradually changes with the change in the displacement amount during the movement of the valve body 22 under the load, and the greater the load force, the greater the displacement of the valve body 22 in the direction from the second end to the first end, the greater the opening degree of the throttle orifice 221, so that the greater the consumption rate of the load-sensitive cushion valve 2 for the rotational inertia, the more efficient the cushion can be performed, and the higher the cushion resistance demand for the large load can be satisfied. It can be seen that, in this embodiment, the choke 221 serving as the buffer structure can make the buffer resistance of the load sensing buffer valve 2 and the load change in a positive correlation manner based on the change of the opening degree of the choke, so as to implement a buffer process more matched with the actual load working condition.

In addition, as can be seen from fig. 3, in this embodiment, the throttling opening 221 is an axial triangular throttling groove, which has the advantages of simple structure, and the buffering resistance of the load sensing buffer valve 2 and the load pressure can be in a continuous linear corresponding relationship, so as to facilitate control and achieve more diversified buffering performance requirements. Of course, the choke 221 may also be configured in other forms (e.g., V-shaped choke groove, etc.) than the axial triangular choke groove, so that the damping resistance of the load sensing damper valve 2 is continuously linearly or non-linearly corresponding to the load pressure.

The spring 23 serves to apply an elastic force to the spool 22 to set the opening pressure of the spool 22. As shown in fig. 3, in this embodiment, the spring 23 is disposed in the first chamber such that the first chamber (the valve chamber I where the spring 23 is located) becomes a spring chamber, and the spring 23 abuts against an end of the first spool portion that is away from the third valve core portion (i.e., the first end of the spool 22, i.e., the left end of the spool 22 in fig. 3). In this way, the spring 23 applies an elastic force to the valve core 22 to enable one end of the third valve core part (i.e., the second end of the valve core 22, that is, the right end of the valve core 22 in fig. 3) far away from the first valve core part to abut against the end wall of the third chamber, so that the valve core 22 can block the communication between the first oil port a and the second oil port B to close the load sensing cushion valve 2 when the first oil port a is not filled with oil or the oil pressure of the first oil port a is small, and only when the load force applied to the first end of the valve core 22 and introduced by the first oil port a reaches a certain preset value (at least, the load force should be greater than the elastic force of the spring 23), the load force can push the valve core 22 to move along the direction from the second end to the first end to communicate the first oil port a and the second oil port B, open the load sensing cushion valve 2. It can be seen that the spring 23 is arranged, so that the load sensing cushion valve 2 has a certain opening pressure and can be kept in a closed state in a normal state, and the load sensing cushion valve 2 can not be buffered in a normal rotation process so as to avoid the influence of buffering on the normal rotation process.

In addition, as described above, in this embodiment, the valve body 21 is further provided with the third port C for communicating the pilot port of the reversing valve 1 with the first chamber, and during the normal rotation, the pilot port of the reversing valve 1 is in the oil passing state, so during the normal rotation, the pilot oil can enter the third chamber through the third port C and act on the first end of the valve core 22, and together with the elastic force exerted by the spring 23, exert an acting force for closing the valve core 22 on the valve core 22, that is, in this embodiment, the elastic force of the spring 23 and the pilot oil acting force of the reversing valve 1 jointly determine the minimum value of the load force capable of pushing the valve core 22 to open, that is, the opening force of the valve core 22 is the sum of the elastic force of the spring 23 and the pilot oil acting force of the reversing valve 1. Because under for only the condition of spring 23 elastic force, this embodiment can obtain bigger case 22 opening pressure based on the third hydraulic fluid port C that adds, consequently, can make load response cushion valve 2 shutting more reliably in normal gyration process, more be favorable to reducing the influence of buffer function to normal gyration process, play the safety protection effect.

Meanwhile, as described above, in this embodiment, the effective pressure acting area of the first end of the spool 22 is also larger than that of the second end of the spool 22, and since in this case, the acting force of the pilot oil on the first end of the spool 22 is larger than that of the load oil on the second end of the spool 22 at the same oil pressure, so that the sum of the acting forces acting on the first end of the spool 22 at the spring side is larger than the acting force (load force) acting on the second end of the spool 22 at the orifice 221 side, it is more favorable to obtain a larger spool opening pressure during normal rotation, and the load-sensing cushion valve 2 is more reliably kept locked during normal rotation.

The elastic force adjusting part 24 is used for adjusting the elastic force of the spring 23 to change the opening pressure of the valve core 22, so that the opening pressure of the valve core 22 can be adjusted. In this embodiment, the spring force adjustment member 24 is a screw that is threadedly engaged with the valve body 21 and extends into the first chamber to abut the spring 23. Based on this, on one hand, the elastic force adjusting component 24 can enable the spring 23 to more reliably abut against the first end of the valve core 22, and on the other hand, the screwing amount of the elastic force adjusting component 24 in the valve body 21 is changed by screwing the elastic force adjusting component 24, and the deformation amount of the spring 23 can also be changed, so that the elastic force of the spring 23 is changed, the adjustment of the elastic force of the spring 23 is realized, the embodiment is convenient for setting different opening pressures of the valve core 22 according to actual requirements, and further different buffering requirements of more engineering machines and more working conditions are met.

In addition, the elastic force adjusting member 24 is provided to adjust the elastic force of the spring 23, and it is also advantageous in that it can be matched with the spool 22 and the direction valve 1 to enable the load sensing cushion valve 2 to be used as a safety valve, because, in this case, the set elastic force of the spring 23, the effective pressure acting area ratio at both ends of the spool 22, the pilot pressure of the direction valve 1, and the like can be matched, so that when the load pressure exceeds the system design pressure, the spool 22 can be opened under the effect of the load pressure introduced from the first port a, and the working oil path is decompressed through the orifice 221, thereby achieving the effect of safety protection.

The first shuttle valve 3 is used as a first pressure selection mechanism to control the communication of the first oil port a with one of the first working oil port D and the second working oil port E, which has a large pressure, so that the first oil port a can lead the load pressure to the second end of the spool 22, and the spool 22 can reliably sense the load pressure.

As shown in fig. 1, in this embodiment, the outlet of the first shuttle valve 3 is communicated with the first oil port a, and two inlets of the first shuttle valve 3 are respectively communicated with the first working oil port D and the second working oil port E, that is, one inlet of the first shuttle valve 3 is communicated with the first working oil port D, and the other inlet of the first shuttle valve 3 is communicated with the second working oil port E. Like this, the great one of pressure in first work hydraulic fluid port D and the second work hydraulic fluid port E can promote first shuttle valve 3 and open for hydraulic oil in the great one of pressure can flow into first hydraulic fluid port A through this first shuttle valve 3 in two work hydraulic fluid ports of rotary motor, and then acts on the second end of case 22.

Because in the rotary motor working process, one oil inlet and another oil return of the first working oil port D and the second working oil port E, the larger pressure in the two is actually the one of the oil inlet, that is, the one for embodying the load pressure, therefore, the larger pressure in the two is communicated to the first oil port A, the load pressure is introduced into the first oil port A actually, and then the second end of the valve core 22 is led to, so that the load sensing buffer valve 2 can sense the load pressure, and the load sensing buffer valve 2 is convenient to provide different buffer resistances according to different loads.

And this embodiment is through setting up first shuttle valve 3, can automatic control load pressure act on the second end of case 22 through first hydraulic fluid port A, and is more convenient, high-efficient and reliable.

The second shuttle valve 4 serves as a second pressure selection mechanism to control the third port C to communicate with one of the first pilot port a and the second pilot port b, which has a relatively large pressure, so that the third port C can introduce the pilot pressure of the directional control valve 1 to the first end of the spool 22, thereby realizing the sensing of the spool 22 to the rotation working state.

As shown in fig. 1, in this embodiment, the outlet of the second shuttle valve 4 is communicated with the third oil port C, and two inlets of the second shuttle valve 4 are respectively communicated with the first pilot oil port a and the second pilot oil port b, that is, one inlet of the second shuttle valve 4 is communicated with the first pilot oil port a, and the other inlet of the second shuttle valve 4 is communicated with the second pilot oil port b. In this way, when the pressures in the first pilot oil port a and the second pilot oil port b are different, the higher pressure one of the first pilot oil port a and the second pilot oil port b can push the second shuttle valve 4 to open, so that the hydraulic oil in the higher pressure one of the two pilot oil ports of the directional control valve 1 can flow into the third oil port C through the second shuttle valve 4, and then act on the first end of the spool 22, and act on the spool 22 together with the elastic force of the spring 23 to apply an acting force for closing the spool 22.

In the normal rotation process, the reversing valve 1 is in the left position or the right position, one of the first pilot oil port a and the second pilot oil port b is generally communicated with oil, the other one of the first pilot oil port a and the second pilot oil port b is not communicated with oil, one of the first pilot oil port a and the second pilot oil port b is higher in pressure, the other one of the first pilot oil port a and the second pilot oil port b is lower in pressure, and the one of the first pilot oil port a and the second pilot oil port b which is higher in pressure is actually communicated with the third oil port C and is actually introduced into the third oil port C and further introduced into the first end of the valve core 22, so that the pilot pressure and the elastic force of the spring 23 can exert acting force on the valve core 22 to close the valve core 22; in the process of turning on and off, the reversing valve 1 reverses to the neutral position, and the first pilot oil port a and the second pilot oil port b are generally not filled with pilot oil any more, so that the pressure of the first pilot oil port a and the pressure of the second pilot oil port b are the same and are not different, and no hydraulic oil acts on the first end of the valve core 22 through the third oil port C. Therefore, one of the first pilot oil port a and the second pilot oil port b with higher pressure is communicated to the third oil port C, so that on one hand, the load sensing buffer valve 2 can sense the pilot pressure and sense the rotation working state by sensing the pilot pressure, namely, sense which one of the normal rotation process and the rotation start-stop process the engineering machinery is in, and further control whether to implement buffering; on the other hand, in the normal rotation process, the pilot pressure is guided to act on the first end of the valve core 22, and the opening pressure of the valve core 22 is increased, so that the valve core 22 can be locked more reliably, the risk that the normal rotation speed is affected by the buffer function is reduced more effectively, and in the rotation start-stop process, the pilot pressure can not act on the first end of the valve core 22 any more, the opening pressure of the valve core 22 is reduced, and the valve core 22 can be opened and buffered more easily under the load action.

In the embodiment, the second shuttle valve 4 is arranged, so that the pilot pressure can be automatically controlled to act on the first end of the valve core 22 through the third oil port C, and the operation is more convenient, efficient and reliable.

The operation of the swing control system of this embodiment is as follows:

(1) in the normal rotation process, the first pilot oil port a or the second pilot oil port b is filled with pilot oil to enable the reversing valve 1 to be reversed from the middle position to the left position or the right position, and pressure oil provided by an oil source flows to the first working oil port D or the second working oil port E of the rotary motor through the oil source connecting port P and the reversing valve 1 and then acts on an executing element to drive a load to work. In the process, the pilot oil flows into the spring cavity of the load sensing cushion valve 2 through the second shuttle valve 4 and the third oil port C and acts on the first end of the valve core 22, so that the valve core 22 is in a closed state under the combined action of the pilot oil and the spring 3, at the moment, the first oil port a and the second oil port B are not communicated, the throttling port 221 does not play a throttling role, and the load sensing cushion valve 2 does not implement a buffering function.

(2) When the rotation is stopped, the first pilot oil port a and the second pilot oil port b do not pass through pilot oil any more, the spring cavity is decompressed, the pilot oil does not apply an acting force on the first end of the valve core 22 any more, the first end of the valve core 2 only has a spring force applied by the spring 23, meanwhile, a load pressure acts on the second end of the valve core 22 through the first shuttle valve 3 and the first oil port a, when the acting force (load force) applied to the second end of the valve core 22 by the load oil is greater than an elastic force (spring force) applied to the first end of the valve core 22 by the spring 23, the valve core 22 is pushed to move along the direction from the second end to the first end, the spring 23 is compressed, the throttling port 221 is gradually opened, and the rotation stopping pressure is stably released by the throttling port 221, so that the rotation buffering function is realized. In this process, because different valve core 22 displacements correspond to different load pressures, and different valve core 22 displacements correspond to different spring 23 compression amounts and different throttle 221 opening degrees, different load forces correspond to different throttle 221 opening degrees, so that the load sensing type rotary damping process of the load sensing damper 2 can be realized, that is: the larger the load force is, the larger the displacement of the valve core 22 is, the larger the opening degree of the throttling port 221 is, the larger the rotation inertia consumption rate is, the larger the buffer resistance is, the smaller the load force is, the smaller the displacement of the valve core 22 is, the smaller the opening degree of the throttling port 221 is, the smaller the rotation inertia consumption rate is, and the smaller the buffer resistance is, so that the buffer resistance of the rotation buffer device can be better matched with different loads, and the various buffer requirements of the engineering machinery under various working conditions are met.

It can be seen that, in the first embodiment, the first oil port a for sensing the load pressure and the throttle orifice 221 with the throttle opening increasing with the increase of the opening displacement of the valve element 22 are arranged in the load sensing buffer valve 2, so that the rotary buffer device can provide buffer resistances matched with different loads on the basis of sensing the load pressure, thereby realizing a buffer process more meeting the requirements of various rotary working conditions, and more effectively improving the smoothness of the rotary start-stop process.

In addition, the first embodiment further arranges the third oil port C for sensing the pilot pressure of the reversing valve 1 in the load sensing cushion valve 2, so that the locking reliability of the load sensing cushion valve 2 in the normal rotation process is effectively improved, and the expected normal rotation process is conveniently realized.

In addition, the first embodiment also provides the elasticity adjusting part 4 in the load sensing cushion valve 2 and provides the effective pressure acting area difference at the two ends of the valve core 22, so that the load sensing cushion valve 2 has the function of a safety valve at the same time, and because a separate safety valve is not required to be specially arranged in this case, the number of elements in the rotation cushion device is reduced, the structure of the rotation cushion device is simplified, and the working reliability of the rotation cushion device is improved.

In order to achieve the effects achieved by the first embodiment, the rotation damper device of the present invention is not limited to the structure of the first embodiment, and will be described with reference to the other three embodiments shown in fig. 4 to 8.

Fig. 4-6 illustrate a second embodiment of the present invention.

As shown in fig. 4 to 6, the structure of the rotary damping device of the second embodiment is different from that of the first embodiment mainly in that, in the second embodiment, the third port C is not provided in the load sensing damping valve 2, namely, the spring cavity of the load sensing cushion valve 2 is not communicated with the pilot oil port of the reversing valve 1 any more, namely, the pilot pressure of the reversing valve 1 is not led into the spring cavity any more, instead, the spring chamber of the load-sensing cushion valve 2 is disposed to communicate with the second port B, which is communicated with the oil tank, and therefore, the arrangement enables the spring cavity of the load sensing buffer valve 2 to be communicated with the oil tank, so that the pressure relief of the spring cavity can be realized, the oil pressure of the spring cavity is smaller and even zero, the opening pressure of the valve core 22 is reduced, therefore, the situation that the valve core 22 cannot be pushed to open by the load pressure introduced by the first oil port a due to the overlarge oil pressure of the spring cavity is prevented. It can be seen that this second embodiment can further ensure reliable implementation of the cushion function by placing the spring chamber of the load sensing cushion valve 2 in communication with the second port B.

Specifically, as can be seen from fig. 6, in order to achieve communication between the spring chamber of the load-sensing cushion valve 2 and the second port B, the second embodiment provides an auxiliary flow passage 222 on the spool 22, and the auxiliary flow passage 222 communicates the spring chamber and the second port B. The valve core 22 is provided with the auxiliary flow passage 222 to communicate the spring cavity of the load sensing cushion valve 2 with the second port B, and the auxiliary flow passage 222 has a short flow path, is easy to process, has a low cost, and has a compact structure. Instead, the auxiliary flow passage 222 may be provided in the valve body 21.

In addition, the arrangement of the second embodiment also makes it possible to provide the load sensing cushion valve 2 with a safety protection function by matching the elastic force of the spring 23 and the effective pressure acting area ratio of both ends of the spool 22 without introducing the pilot pressure.

Fig. 7 shows a third embodiment of the invention.

As shown in fig. 7, in the third embodiment, the load sensing cushion valve 2 is still provided with the third port C, but the cushion structure on the valve core 22 no longer includes only one gradual throttle 221, but includes a plurality of (specifically, three) non-gradual throttle 221, and the plurality of throttle 221 is arranged at intervals along the direction from the second end to the first end, that is, the plurality of throttle 221 is distributed discretely. Specifically, as can be seen from fig. 7, in this embodiment, the chokes 221 are actually throttle holes, and the throttle opening of each choke 221 itself does not vary in the direction from the second end to the first end, i.e., the throttle area of each choke 221 is constant. In this case, when the valve core 22 is opened under the load force, as the number of the orifices 221 for communicating the first oil port a and the second oil port B increases with the increase of the opening displacement of the valve core 22, and the orifice area of the buffer structure gradually increases, the buffer resistance of the load buffer valve 2 can still be changed in positive correlation with the load, and further, a buffer process which is more matched with different loads is realized.

As can be seen, in the third embodiment, the valve body 22 is provided with the plurality of non-gradual-change type chokes 221 distributed discretely as the buffer structure, so that the load-sensitive buffer process can be realized, and the buffer effect of the rotation buffer device can be effectively improved.

In addition, in the third embodiment, the hole diameter and the position of each throttle orifice 221 can be designed to meet the buffering requirement of more load conditions. For example, in fig. 7, the apertures of the respective chokes 221 are different, and the apertures of the different chokes 221 gradually decrease in a direction from the second end to the first end; the spacing between adjacent chokes 221 is also different, and the spacing between adjacent chokes 221 gradually decreases in a direction from the second end to the first end. Of course, in other embodiments not shown in the drawings, the aperture variation law of different chokes 221 and the pitch variation law between adjacent chokes 221 may be set in other manners as long as the load sensing type buffering process can be realized.

In addition, as can be seen from fig. 7, in the third embodiment, in order to facilitate the first oil port a to communicate with the discretely distributed chokes 221, the valve core 22 is further provided with an intermediate flow passage 223, and the intermediate flow passage 223 communicates the first oil port a with the chokes 221, so that the first oil port a can communicate with the chokes 221 through the intermediate flow passage 223, and the third embodiment has a simple and compact structure and is convenient to process.

Fig. 8 shows a fourth embodiment of the invention.

As shown in fig. 8, the fourth embodiment is substantially the same as the third embodiment, and the damping structure still includes a plurality of non-gradual chokes 221 distributed discretely, but the difference between the two embodiments is mainly that the third port C is no longer included in the load-sensing damping valve 2, and the spring chamber of the load-sensing damping valve 2 is communicated with the second port B through the auxiliary flow passage 222 provided on the spool 22. Among other things, the benefit of providing the auxiliary flow passage 222 to communicate the spring chamber of the load sensing cushion valve 2 with the second port B can be understood with reference to the second embodiment.

Although in the four embodiments shown in fig. 1-8, the buffer structure either comprises only one gradual choke 221, or a plurality of non-gradual chokes 221 distributed discretely, it should be noted that the buffer structure is not limited to these two implementations, for example, in other embodiments of the present invention, at least two discretely distributed gradual chokes 221 may be provided as a buffer structure, namely, at least two throttling ports 221 which are distributed discretely are arranged, the throttling opening degree of each throttling port 221 in the at least two throttling ports 221 is increased along with the increase of the opening displacement of the valve core 22, alternatively, only some of the at least two orifices 221 distributed discretely may be arranged so that the throttle opening of the orifice 221 increases as the opening displacement of the valve body 22 increases, all of these can realize the load-sensing type buffering function, and are also within the protection scope of the present invention.

In addition, the first shuttle valve 3 is adopted as the first pressure selection mechanism and the second shuttle valve 4 is adopted as the second pressure selection mechanism in the four embodiments shown in fig. 1 to 8, but the first pressure selection mechanism and the second pressure selection mechanism can also adopt other structural forms besides the shuttle valves, for example, instead of the first shuttle valve 3, the first pressure selection mechanism can also be arranged to include a first check valve and a second check valve, an inlet of the first check valve is communicated with the first working oil port D of the rotary motor, an inlet of the second check valve is communicated with the second working oil port E of the rotary motor, and an outlet of the first check valve and an outlet of the second check valve are communicated with the first oil port a; instead of the second shuttle valve 4, the second pressure selection mechanism may be further configured to include a third check valve and a fourth check valve, an inlet of the third check valve is communicated with the first pilot oil port a, an inlet of the fourth check valve is communicated with the second pilot oil port b, and an outlet of the third check valve and an outlet of the fourth check valve are both communicated with the third oil port C.

In summary, the rotary buffering device can provide different buffering resistances for different loads by arranging the load sensing buffering valve 2 which can sense the load pressure and the opening displacement of the load sensing buffering valve 2 is increased along with the load pressure, and arranging the buffering structure of which the throttling opening is increased along with the opening displacement of the valve core on the load sensing buffering valve 2, so that the rotary buffering device can meet the buffering requirements of different working conditions in a matching manner, and can achieve better buffering effect. Meanwhile, the rotary buffering device is simple in structure, convenient to control and high in working reliability, and the buffering failure or over-buffering phenomenon is not easy to occur.

The rotation buffer device is applied to a rotation control system and engineering machinery (such as a crane), and can effectively improve the smoothness of rotation starting and stopping. The rotary control device can meet various buffering requirements of different loads, and has the advantages of low cost, convenience in control and the like, so that the rotary control device is suitable for large-tonnage engineering machinery, is also suitable for middle-tonnage and small-tonnage engineering machinery, and has a wider application range and a better application prospect. Therefore, the invention also provides a rotation control system and engineering machinery. Wherein, the gyration control system includes a gyration motor and the gyration buffering device of the invention. The engineering machine comprises the rotary control system.

The above description is only exemplary of the present invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A slew cushioning device, comprising:

load sensing trim valve (2) comprising:

a valve cavity (I);

the first oil port (A) is communicated with the valve cavity (I);

the second oil port (B) is communicated with the valve cavity (I) and is used for being communicated with an oil tank;

the valve core (22) is movably arranged in the valve cavity (I) and controls the connection and disconnection between the first oil port (A) and the second oil port (B) by moving in the valve cavity (I); and the combination of (a) and (b),

the spring (23) is arranged in the valve cavity (I) and abuts against the first end of the valve core (22);

wherein:

the first oil port (A) guides one of a first working oil port (D) and a second working oil port (E) of a rotary motor of the engineering machinery, which has a larger pressure, to act on a second end, opposite to the first end, of the valve core (22);

the valve core (22) is provided with a buffer structure, the first oil port (A) is communicated with the second oil port (B) through the buffer structure in the process that the valve core (22) moves along the direction from the second end to the first end, and the flow area of the buffer structure is gradually increased;

the rotary buffering device further comprises a reversing valve (1), the reversing valve (1) is provided with a pilot oil port, and the pilot oil port controls one of a first working oil port (D) and a second working oil port (E) of the rotary motor to be communicated with an oil source and the other to be communicated with an oil tank by controlling the reversing of the reversing valve (1); and the load sensing cushion valve (2) further comprises a third oil port (C), and the third oil port (C) is communicated with the pilot oil port and a valve cavity (I) where the spring (23) is located.

2. The slewing damping device according to claim 1, characterized in that the damping structure comprises a choke (221), wherein: the throttle area of the throttle orifices (221) is gradually reduced along the direction from the second end to the first end, and/or the number of the throttle orifices (221) is at least two, and the at least two throttle orifices (221) are arranged at intervals along the direction from the second end to the first end.

3. The rotary damping device according to claim 2, wherein the number of the throttling ports (221) is at least two, and an intermediate flow passage (223) is further provided on the valve core (22), and the first oil port (a) is communicated with the at least two throttling ports (221) through the intermediate flow passage (223).

4. The rotary damping device according to claim 1, further comprising a first pressure selection mechanism, wherein the first pressure selection mechanism is communicated with the first oil port (a) and controls the first oil port (a) to be communicated with one of the first working oil port (D) and the second working oil port (E) of the rotary motor, which has a larger pressure.

5. The rotary damping device according to claim 4, wherein the first pressure selection mechanism comprises a first shuttle valve (3), an outlet of the first shuttle valve (3) is communicated with the first oil port (A), and two inlets of the first shuttle valve (3) are respectively communicated with a first working oil port (D) and a second working oil port (E) of the rotary motor; or, the first pressure selection mechanism comprises a first one-way valve and a second one-way valve, an inlet of the first one-way valve is communicated with a first working oil port (D) of the rotary motor, an inlet of the second one-way valve is communicated with a second working oil port (E) of the rotary motor, and an outlet of the first one-way valve and an outlet of the second one-way valve are communicated with the first oil port (A).

6. The slew damping device of claim 1, wherein the effective pressure effective area of the first end is greater than the effective pressure effective area of the second end.

7. The rotary damping device according to claim 1, characterized in that the load sensing damping valve (2) further comprises an elastic force adjusting member (24), and the elastic force adjusting member (24) adjusts the elastic force of the spring (23) by adjusting the deformation amount of the spring (23).

8. The slewing damping device according to claim 1, wherein the pilot oil ports comprise a first pilot oil port (a) and a second pilot oil port (b), the first pilot oil port (a) controls the reversing valve (1) to reverse between a middle position and a left position, and the second pilot oil port (b) controls the reversing valve (1) to reverse between a middle position and a right position; the third oil port (C) is communicated with the valve cavity (I) where the spring (23) is located and one of the first pilot oil port (a) and the second pilot oil port (b) with larger pressure.

9. The rotary damping device according to claim 8, further comprising a second pressure selection mechanism, wherein the third oil port (C) is communicated with one of the first pilot oil port (a) and the second pilot oil port (b) having a larger pressure through the second pressure selection mechanism.

10. The rotary damping device according to claim 9, wherein the second pressure selection mechanism comprises a second shuttle valve (4), an outlet of the second shuttle valve (4) is communicated with the third oil port (C), and two inlets of the second shuttle valve (4) are respectively communicated with the first pilot oil port (a) and the second pilot oil port (b); or the second pressure selection mechanism comprises a third one-way valve and a fourth one-way valve, an inlet of the third one-way valve is communicated with the first pilot oil port (a), an inlet of the fourth one-way valve is communicated with the second pilot oil port (b), and an outlet of the third one-way valve and an outlet of the fourth one-way valve are communicated with the third oil port (C).

11. A rotation damping device according to any one of claims 1-7, characterized in that the valve chamber (I) in which the spring (23) is located is adapted to communicate with the tank.

12. The slewing damping device according to claim 11, characterized in that the valve chamber (I) in which the spring (23) is located communicates with the second oil port (B) so that the valve chamber (I) in which the spring (23) is located communicates with the oil tank through the second oil port (B).

13. The rotary damping device according to claim 12, wherein an auxiliary flow passage (222) is further provided on the valve core (22), and the auxiliary flow passage (222) communicates the valve cavity (I) where the spring (23) is located with the second oil port (B).

14. A swing control system comprising a swing motor, characterized by further comprising the swing buffering device of any one of claims 1 to 13, wherein the first pressure selection mechanism of the swing buffering device controls the communication between the first oil port (a) and one of the first working oil port (D) and the second working oil port (E) of the swing motor, which has a higher pressure.

15. A work machine comprising a swing control system according to claim 14.