Load compensated swing cushion valve, swing hydraulic system and truck crane

Abstract

The present application belongs to the field of crane slewing control, and discloses a load compensation slewing buffer valve, a slewing hydraulic system and a truck crane. The load compensation slewing buffer valve comprises a valve body, an overflow valve and an adjustable flow valve. The valve body is provided with a valve body oil inlet, a valve body oil return and a first internal buffer flow channel connecting the valve body oil inlet and the valve body oil return. The overflow valve is arranged in the first internal buffer flow channel. The adjustable flow valve is arranged in series with the overflow valve in the first internal buffer flow channel and located at the downstream end of the overflow valve. The opening degree of the throttle valve port of the adjustable flow valve is inversely proportional to the oil pressure of the overflow oil outlet of the overflow valve. When the truck crane slews, the slewing inertia moment generated by the start and stop of the slewing mechanism is smaller, which can reduce the violent shaking of the crane and protect the structural damage of the crane. When the slewing overspeed is caused by uneven ground, compensation pressure can be provided to offset the negative load, so that the slewing speed is only controlled by the operator and is not related to the size of the load.

Description

Technical Field

[0001] This invention belongs to the field of crane slewing control, specifically relating to a load-compensating slewing buffer valve, a slewing hydraulic system, and a truck crane. Background Technology

[0002] The slewing mechanism of a truck crane has a huge moment of rotational inertia when starting and stopping. If the slewing brake is used directly for braking, it will generate a large impact force, causing the crane to shake violently and even suffer structural damage. Figure 1 As shown, before the slewing brake of the truck crane is engaged, most of the kinetic energy of the inertial moment is dissipated through buffer valves PR1 and PR2 in a throttling and energy-consuming manner. However, the buffer valves are direct-acting relief valves, which suffer from slow response, large pressure overshoot, and large pressure fluctuations when the opening is small. Furthermore, they cannot provide corresponding buffering force based on the magnitude of the slewing moment of inertia. More seriously, if the buffer valves fail to operate during slewing, the slewing system cannot decelerate on uneven ground, making precise control of the slewing speed difficult and potentially leading to overspeeding, posing a safety hazard. Summary of the Invention

[0003] To address the aforementioned defects or deficiencies, this invention provides a load-compensated slewing buffer valve, a slewing hydraulic system, and a truck crane, which can reduce slewing impact, mitigate slewing overspeed problems, and ensure that the slewing mechanism has a smaller slewing moment of inertia during start-up and shutdown.

[0004] To achieve the above objectives, the present invention first provides a load-compensated rotary buffer valve, comprising:

[0005] The valve body is provided with a valve body oil inlet, a valve body oil return port, and a first internal buffer flow channel connecting the valve body oil inlet and the valve body oil return port;

[0006] An overflow valve is disposed in the first internal buffer channel; and

[0007] An adjustable flow valve is connected in series with the overflow valve in the first internal buffer channel and is located at the downstream end of the overflow valve;

[0008] The opening degree of the throttle valve of the adjustable flow valve is inversely proportional to the oil pressure at the overflow outlet of the overflow valve.

[0009] In some embodiments, the adjustable flow valve includes:

[0010] The throttle valve control chamber is connected to the overflow outlet of the overflow valve;

[0011] The throttle valve chamber is provided with the throttle valve port, which connects the overflow outlet of the relief valve with the return port of the valve body; and

[0012] A throttle valve spool, one end of which is connected with a first control piston extending into the throttle valve control chamber, and the other end of which is connected with a first reset elastic member, is moved along the throttle valve chamber under the combined force of the first control piston and the first reset elastic member acting in opposite directions to adjust the opening of the throttle valve port.

[0013] In some embodiments, a second internal buffer flow channel connecting the valve body oil inlet and the valve body oil return is further provided in the valve body, and a hydraulic control check valve is provided in the second internal buffer flow channel.

[0014] The hydraulic control check valve comprises:

[0015] A check valve control chamber is provided with a valve body control oil port.

[0016] A check valve chamber is connected with the valve body oil inlet through a check valve port.

[0017] A check valve spool, one end of which is connected with a second control piston extending into the check valve control chamber, and the other end of which is connected with a second reset elastic member, is moved along the check valve chamber under the combined force of the second control piston and the second reset elastic member acting in opposite directions to adjust the opening of the check valve port.

[0018] In some embodiments, the throttle valve control chamber, the throttle valve chamber, the check valve chamber and the check valve control chamber are sequentially arranged along a first direction in the valve body, and the first control piston, the first reset elastic member, the second reset elastic member and the second control piston are sequentially and linearly extended along the first direction.

[0019] In some embodiments, an oil inlet chamber provided with the valve body oil inlet is further included in the valve body, and the oil inlet chamber is arranged between the check valve chamber and the check valve control chamber along the first direction.

[0020] In some embodiments, along the first direction, a first end of the first reset elastic member elastically abuts against the throttle valve spool, a first end of the second reset elastic member elastically abuts against the check valve spool, and a second end of the first reset elastic member and a second end of the second reset elastic member elastically abut against two sides of an elastic member mounting seat.

[0021] In some embodiments, the elastic member mounting seat is a movable seat body capable of moving along the first direction.

[0022] In some embodiments, a peripheral wall of the check valve spool is provided with a spool through port, and the spool through port connects the throttle valve chamber and the check valve chamber.

[0023] In some embodiments, the valve body oil inlet is in communication with the valve body control oil port.

[0024] In addition, the application further provides a slewing hydraulic system comprising the load compensation slewing buffer valve.

[0025] In some embodiments, the slewing hydraulic system comprises:

[0026] a slewing hydraulic circuit comprising a slewing pump, a first working oil path connected to a first end of the slewing pump, and a second working oil path connected to a second end of the slewing pump;

[0027] a shuttle valve, a first comparison end of the shuttle valve being connected to the first working oil path and a second comparison end being connected to the second working oil path, an oil outlet end of the shuttle valve being connected to the valve body oil inlet of the load compensation slewing buffer valve.

[0028] In addition, the application further provides an automobile crane comprising the slewing hydraulic system.

[0029] In the load compensation slewing buffer valve and the slewing hydraulic system, the pulse pressure caused by the inertial moment and the like enters the valve body of the load compensation slewing buffer valve from the valve body oil inlet, opens the overflow valve and the adjustable flow valve along the first internal buffer flow path in turn, and finally flows out from the valve body oil return port, so that the load compensation slewing buffer valve can play a good bypass overflow role in the slewing hydraulic system, reduce the pressure impact, and thus reduce the slewing impact and the slewing overspeed problem. When the slewing mechanism is started or stopped, the corresponding throttling buffer force can be provided according to the size of the slewing inertial moment, the impact generated by the slewing start and stop can be quickly dissipated, and the slewing inertial moment is small, so that the slewing action of the automobile crane can be more accurately controlled.

[0030] Other features and advantages of the application will be described in detail in the following specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0031] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, and are used together with the following specific embodiments to explain the application, but do not constitute a limitation on the application. In the drawings:

[0032] Figure 1 is a hydraulic schematic diagram of the existing slewing hydraulic system of the automobile crane;

[0033] Figure 2 is a hydraulic schematic diagram of the slewing hydraulic system according to the specific embodiments of the application;

[0034] Figure 3Structure principle diagram of the load-compensated rotary cushion valve in the pumping hydraulic system according to the specific embodiment of the present application.

[0035] Explanation of reference numerals

[0036] 1 first control piston 2 adjustable flow valve

[0037] 3 overflow valve 4 hydraulic control check valve

[0038] 5 second control piston 6 first reset elastic member

[0039] 7 second reset elastic member 8 oil inlet chamber

[0040] 9 elastic member mounting seat 10 valve core through hole

[0041] 21 throttle valve port 22 throttle valve control chamber

[0042] 23 throttle valve chamber 24 throttle valve core

[0043] 31 overflow oil outlet port 41 check valve control chamber

[0044] 42 check valve chamber 43 check valve port

[0045] 44 check valve core X valve body control oil port

[0046] 100 load-compensated rotary cushion valve 101 valve body

[0047] 200 shuttle valve 300 main valve

[0048] A0 valve body oil inlet port T0 valve body oil inlet port

[0049] L1 first internal cushion flow passage L2 second internal cushion flow passage

[0050] P main valve oil inlet port T main valve oil return port

[0051] A first working oil port B second working oil port

[0052] a first solenoid valve b second solenoid valve Specific embodiment

[0053] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely intended to illustrate and explain the present application, and are not intended to limit the present application.

[0054] The load-compensated rotary cushion valve, rotary hydraulic system and automobile crane according to the present application will be described below with reference to the accompanying drawings.

[0055] Referring toFigure 3 In one embodiment of the present application, a new type of load compensation rotary buffer valve 100 is first disclosed, comprising:

[0056] A valve body 101 is provided with a valve body oil inlet A0, a valve body oil return port T0, and a first internal buffer flow channel L1 connecting the valve body oil inlet A0 and the valve body oil return port T0;

[0057] An overflow valve 3 is arranged in the first internal buffer flow channel L1; and

[0058] An adjustable flow valve 2 is arranged in series with the overflow valve 3 in the first internal buffer flow channel L1 and located at the downstream end of the overflow valve 3;

[0059] Wherein, the opening degree of the throttle valve port 21 of the adjustable flow valve 2 is inversely proportional to the oil pressure of the overflow oil outlet 31 of the overflow valve 3.

[0060] As can be seen, when the pulse pressure higher than the set value enters the valve body 101 from the valve body oil inlet A0 along the first internal buffer flow channel L1, a part of the overflow oil can be shunted to the throttle valve control chamber 22 to be described below at the overflow oil outlet 31, and the majority flows to the adjustable flow valve 2, and after throttling through the throttle valve port 21, it flows out from the valve body oil return port T0, so that when it is combined into the working oil circuit of the rotary hydraulic system as shown in the figure, it plays a good bypass overflow role, reduces pressure impact, and thus can reduce rotary impact and reduce rotary overspeed problems. Figure 2

[0061] In particular, when the rotary mechanism starts and stops, since the opening degree of the throttle valve port 21 of the adjustable flow valve 2 is inversely proportional to the oil pressure of the overflow oil outlet 31 of the overflow valve 3, a corresponding throttling buffer force can be provided according to the size of the rotary inertia moment, the impact generated by the start and stop of the rotary is quickly dissipated, and the smaller rotary inertia moment can more accurately control the rotary action of the truck crane.

[0062] In order to realize the inverse proportion between the opening degree of the throttle valve port 21 and the oil pressure of the overflow oil outlet 31, the adjustable flow valve 2 adopts a hydraulic control form, that is, in one embodiment, the adjustable flow valve 2 can include:

[0063] A throttle valve control chamber 22 is connected to the overflow oil outlet 31 of the overflow valve 3;

[0064] A throttle valve chamber 23 is provided with a throttle valve port 21 connecting the overflow oil outlet 31 of the overflow valve 3 and the valve body oil return port T0; and

[0065] ​The throttle spool 24 has one end connected with the first control piston 1 extending into the throttle control chamber 22, and the other end connected with the first reset spring 6. The throttle spool 24 is pushed by the combined force of the first control piston 1 and the first reset spring 6 to move along the throttle chamber 23 to adjust the opening of the throttle port 21.

[0066] In this way, when the overflow oil pressure at the overflow oil outlet 31 is large, the first control piston 1 pushes the throttle spool 24 to move right more, which makes the throttle port 21 open smaller and the throttling buffering force larger.

[0067] Further, the valve body 101 is also provided with a second internal buffering flow channel L2 connecting the valve body oil inlet A0 and the valve body oil return port T0, and the second internal buffering flow channel L2 is provided with a hydraulic control one-way valve 4.

[0068] The hydraulic control one-way valve 4 can include:

[0069] The one-way valve control chamber 41 is provided with a valve body control oil port X;

[0070] The one-way valve chamber 42 is connected with the valve body oil inlet A0 through the one-way valve port 43;

[0071] The one-way valve spool 44 has one end connected with the second control piston 5 extending into the one-way valve control chamber 41, and the other end connected with the second reset spring 7. The one-way valve spool 44 is pushed by the combined force of the second control piston 5 and the second reset spring 7 to move along the one-way valve chamber 42 to adjust the opening of the one-way valve port 43.

[0072] In this way, after the pulse pressure enters the valve body 101 from the valve body oil inlet A0, it can be divided into two paths, i.e. the first internal buffering flow channel L1 and the second internal buffering flow channel L2. When passing through the second internal buffering flow channel L2, the oil from the valve body oil inlet A0 enters the oil inlet chamber 8 in the valve body 101, then enters the one-way valve chamber 42 through the one-way valve port 43, and can further pass through the valve spool through hole 10 provided on the peripheral wall of the one-way valve spool 44 to connect the throttle chamber 23 and the one-way valve chamber 42, and then flow out from the valve body oil return port T0 after throttling. Therefore, the second internal buffering flow channel L2 also has a good throttling buffering effect.

[0073] In terms of structural layout, in particular, Figure 3 In the valve body 101 shown, the throttle control chamber 22, the throttle chamber 23, the one-way valve chamber 42 and the one-way valve control chamber 41 are sequentially distributed along the first direction (i.e. the horizontal direction of the valve body 101 shown) in the valve body, and the first control piston 1, the first reset spring 6, the second reset spring 7 and the second control piston 5 are sequentially and linearly extended along the first direction. Such a structure layout in the valve body is more compact and the flow channel is shorter.

[0074] The valve body 101 further comprises an oil inlet cavity 8 provided with a valve body oil inlet A0, the oil inlet cavity 8 is between the one-way valve cavity 42 and the one-way valve control cavity 41 along the first direction. In this way, the second control piston 5 is acted on by the pressure of the oil inlet cavity 8 and the pressure of the valve body control oil port X, in the present embodiment, the valve body oil inlet A0 is communicated with the valve body control oil port X, that is, the oil pressure of the valve body oil inlet A0 and the valve body control oil port X is the same, so that in the case that there is an area difference on the left and right sides of the second control piston 5, the second control piston 5 can be pushed to move left to open the one-way valve port 43 against the second reset elastic member 7.

[0075] Referring to Figure 3 , along the first direction, that is, the horizontal direction of the valve body 101, the first end of the first reset elastic member 6 elastically abuts against the throttle valve spool 24, the first end of the second reset elastic member 7 elastically abuts against the one-way valve spool 44, and the second end of the first reset elastic member 6 and the second end of the second reset elastic member 7 elastically abut against both sides of the elastic member mounting seat 9. Among them, the elastic member mounting seat 9 can be a fixed wall, but in the present embodiment, the elastic member mounting seat 9 is a movable seat body that can move along the first direction. In this way, the oil pressure of the throttle valve control cavity 22 can also act on the one-way valve spool 44, that is, the opening of the one-way valve port 43 is also affected by the load pressure.

[0076] The above combined Figure 2 The specific embodiments of the present application set forth the novel load compensation rotary buffer valve 100 according to the present application. On this basis, the present application also provides a rotary hydraulic system, as shown in Figure 2 , the rotary hydraulic system comprises the load compensation rotary buffer valve 100.

[0077] Specifically, the rotary hydraulic system can comprise:

[0078] a rotary hydraulic circuit comprising a rotary pump (not shown), a first working oil path connected to a first end of the rotary pump, and a second working oil path connected to a second end of the rotary pump;

[0079] a shuttle valve 200, the first comparison end of the shuttle valve 200 is connected to the first working oil path and the second comparison end is connected to the second working oil path, and the oil outlet end of the shuttle valve 200 is connected to the valve body oil inlet A0 of the load compensation rotary buffer valve 100.

[0080] Wherein, by adding shuttle valve 200, the high pressure oil generated by impact in the rotary hydraulic circuit can be guided to the valve body inlet oil port A0 and the valve body control oil port X of the load compensation rotary buffer valve 100. After the overflow throttle buffer of the load compensation rotary buffer valve 100, the pulse pressure is relieved and the pressure impact is reduced. Specifically, the first working oil port A and the second working oil port B are connected to the first working oil circuit and the second working oil circuit of the rotary pump respectively, and the main valve inlet oil port P and the main valve return oil port T of the main valve 300 are connected to the main pump (not shown) and the return oil tank respectively. The main valve 300 adopts an electromagnetic reversing valve, including the first electromagnetic valve a and the second electromagnetic valve b at the left and right ends.

[0081] This rotary hydraulic system can be applied to engineering machinery with rotary devices, such as common truck cranes. Through rationalized system control, when the truck crane rotates, the rotary mechanism has a smaller rotary inertia moment at start and stop, reducing the severe shaking of the crane and protecting the structural damage of the crane. Moreover, the load compensation rotary buffer valve 100 has fast response, small pressure overshoot, and no pressure fluctuation at small opening. Finally, the problem of the buffer valve not working during rotation and the rotation system being unable to decelerate when the ground is uneven is reduced, the rotation speed can be better accurately controlled, the rotation is stably carried out, and the safety hidden danger is eliminated.

[0082] Specifically, in the rotary overflow working condition, when the main valve 300 switches to left or right movement instantaneously, the pressure oil generates pulse pressure due to inertia resistance moment, when the pulse pressure is higher than the set value, the high pressure oil enters the load compensation rotary buffer valve 100 from the shuttle valve 200, opens the overflow valve 3, and flows from the valve body inlet oil port T0 to the valve body 101 return tank, which plays a bypass overflow role to reduce pressure impact.

[0083] In the steady flow condition of rotation, the pulse pressure is reduced after overflow, but the unstable movement at the start and stop of rotation will form the fluctuation of flow and pressure, a part of pressure oil acts on the right end of the second control piston 5 through the valve body control oil port X, thereby pushing the opening hydraulic control check valve 4. At the same time, the pressure generated by the load acts on the left end surface of the first control piston 1, pushing the throttle valve core 24 of the adjustable flow valve 2 to move right, balancing with the spring force of the first reset elastic member 6, so that the adjustable flow valve 2 is in a certain position, through the special design of the throttle valve port 21, the back pressure generated by the flow through the throttle opening at this time is balanced with the load, ensuring that the flow greater than the design value passes through the adjustable flow valve 2 and the opening hydraulic control check valve 4, and finally flows back to the oil tank from the valve body oil inlet T0. In this way, under the condition of generating appropriate back pressure, the rotation can be accelerated smoothly. When the load changes, the pressure generated by the load changes, the pressure acting on the left end of the second control piston 5 changes, thereby changing the opening size of the adjustable flow valve. When the load increases, the second control piston 5 pushes the throttle valve core 24 to move right, and the opening degree of the throttle valve port 21 decreases, and the pressure generated by the full flow through the throttle valve port 21 increases, which is adapted to the load.

[0084] The present application controls the system reasonably, so that the rotation mechanism has a small rotation inertia moment when starting and stopping during the rotation of the automobile crane, reduces the violent shaking of the crane, and protects the structural damage of the crane. At the same time, the problem that the buffer valve does not work during the rotation or the rotation system cannot slow down when the ground is uneven is reduced, the rotation speed is accurately controlled, the rotation is stably carried out, the safety hidden danger is eliminated, and when the rotation overspeed is caused by the uneven ground, compensation pressure can be provided to offset the negative load, so that the rotation speed is only controlled by the operator and is not related to the size of the load.

[0085] In the description of the present application, it should be understood that the terms "first", "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0086] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and other terms should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection or communication with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0087] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0088] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above-described embodiments within the scope of the present application.

Claims

1. A load-compensated rotary buffer valve, characterized in that, The load-compensated rotary buffer valve (100) includes: The valve body (101) is provided with a valve body oil inlet (A0), a valve body oil return port (T0), and a first internal buffer flow channel (L1) connecting the valve body oil inlet (A0) and the valve body oil return port (T0). An overflow valve (3) is disposed in the first internal buffer channel (L1); and An adjustable flow valve (2) is connected in series with the overflow valve (3) in the first internal buffer flow channel (L1) and located downstream of the overflow valve (3). The opening degree of the throttle port (21) of the adjustable flow valve (2) is inversely proportional to the oil pressure of the overflow outlet (31) of the overflow valve (3). The adjustable flow valve (2) includes: The throttle valve control chamber (22) is connected to the overflow outlet (31) of the overflow valve (3); The throttle valve chamber (23) is provided with the throttle valve port (21) connecting the overflow outlet (31) of the overflow valve (3) and the return oil port (T0) of the valve body; and A throttle valve core (24) is connected at one end to a first control piston (1) that extends into the throttle valve control chamber (22), and at the other end to a first reset elastic element (6). The throttle valve core (24) moves along the throttle valve chamber (23) under the combined force of the first control piston (1) and the first reset elastic element (6) which act in opposite directions to each other, so as to adjust the opening of the throttle valve port (21). The valve body (101) is further provided with a second internal buffer channel (L2) connecting the valve body oil inlet (A0) and the valve body oil return port (T0), and a hydraulic control check valve (4) is provided in the second internal buffer channel (L2).

2. The load-compensating rotary buffer valve according to claim 1, characterized in that, The hydraulic control check valve (4) includes: The one-way valve control chamber (41) is provided with a valve body control oil port (X); The one-way valve chamber (42) is connected to the oil inlet (A0) of the valve body through the one-way valve port (43); One-way valve core (44), the valve port end of the one-way valve core (44) is connected to a second control piston (5) that extends into the one-way valve control chamber (41), and the other end is connected to a second reset elastic element (7). The one-way valve core (44) moves along the one-way valve chamber (42) under the combined force of the second control piston (5) and the second reset elastic element (7) which act in opposite directions to each other, so as to adjust the opening degree of the one-way valve port (43).

3. The load-compensating rotary buffer valve according to claim 2, characterized in that, The throttle valve control chamber (22), the throttle valve chamber (23), the one-way valve chamber (42), and the one-way valve control chamber (41) are distributed sequentially along a first direction within the valve body, and the first control piston (1), the first reset elastic element (6), the second reset elastic element (7), and the second control piston (5) extend linearly along the first direction.

4. The load-compensating rotary buffer valve according to claim 3, characterized in that, The valve body (101) also includes an oil inlet chamber (8) with an oil inlet (A0) of the valve body, and the oil inlet chamber (8) is located between the one-way valve chamber (42) and the one-way valve control chamber (41) along the first direction.

5. The load-compensating rotary buffer valve according to claim 3, characterized in that, Along the first direction, the first end of the first reset elastic member (6) elastically abuts against the throttle valve core (24), the first end of the second reset elastic member (7) elastically abuts against the one-way valve core (44), and the second ends of the first reset elastic member (6) and the second ends of the second reset elastic member (7) elastically abut against both sides of the elastic member mounting base (9).

6. The load-compensating rotary buffer valve according to claim 5, characterized in that, The elastic element mounting base (9) is a movable base that can move along the first direction.

7. The load-compensating rotary buffer valve according to claim 3, characterized in that, The peripheral wall of the one-way valve core (44) is provided with a valve core through port (10), which connects the throttle valve chamber (23) and the one-way valve chamber (42).

8. The load-compensating rotary buffer valve according to any one of claims 2 to 7, characterized in that, The valve body oil inlet (A0) is connected to the valve body control oil port (X).

9. A rotary hydraulic system, characterized in that, The rotary hydraulic system includes a load-compensated rotary buffer valve (100) according to any one of claims 1 to 8.

10. The rotary hydraulic system according to claim 9, characterized in that, The rotary hydraulic system includes: A rotary hydraulic circuit includes a rotary pump, a first working oil circuit connected to a first end of the rotary pump, and a second working oil circuit connected to a second end of the rotary pump. A shuttle valve (200) has a first comparison terminal connected to the first working oil circuit and a second comparison terminal connected to the second working oil circuit. The outlet end of the shuttle valve (200) is connected to the valve body inlet (A0) of the load-compensating rotary buffer valve (100).

11. A truck crane, characterized in that, The truck crane includes the slewing hydraulic system according to claim 9 or 10.

Images