Hydraulic slewing buffer system and crane

Abstract

The present invention provides a hydraulic slewing buffer system and a crane, belonging to the technical field of hydraulic systems. The hydraulic slewing buffer system includes an oil inlet, an oil return port, a slewing motor, a reversing valve, a shuttle valve and an energy storage device. The reversing valve is connected between the oil inlet, the oil return port, the oil inlet of the slewing motor and the oil outlet of the slewing motor. The shuttle valve is connected in parallel to the circuit between the reversing valve and the slewing motor. The outlet of the shuttle valve is connected to two interconnected oil circuits, one of which is connected to the energy storage device to store hydraulic energy in the energy storage device, and the other oil circuit can release the hydraulic energy in the energy storage device to the slewing motor. The slewing stability performance can be improved, energy recovery and utilization can be achieved, the system sensitivity to the cleanliness of the oil is greatly reduced, and the influence of the overflow valve response performance on the slewing stability is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic slewing buffer system and a crane. Background Art

[0002] Cranes are a type of operating equipment that is commonly used in construction. They are controlled by a hydraulic system, in which the slewing hydraulic system controls the slewing mechanism of the crane to slew.

[0003] At present, the principle of the slewing hydraulic system of small and medium tonnage truck cranes is as follows: Figure 1 As shown, when the reversing valve 1 is in the left position, the pressure oil drives the rotary motor 5 to rotate through the left passage of the reversing valve 1. At the moment of starting, due to the damping of the oil return port in the reversing valve 1, there is a certain back pressure at the oil return port of the rotary motor 5 to prevent the start-up impact. When the reversing valve 1 transitions from the left position to the middle position, the pressure of the oil outlet B of the rotary motor is too high due to the inertia of the rotary motor 5. At this time, part of the pressure oil at the oil outlet B of the rotary motor is supplied to the oil inlet A of the rotary motor through the one-way relief valve 3 to prevent the rotary motor 5 from sucking air; the other part is supplied to the oil inlet A of the rotary motor through the shuttle valve 4 after the damping 6 to open the relief valve 8 to achieve the stability of the rotation. When the reversing valve 1 is switched to the middle position, and the electromagnetic reversing valve 7 is energized and in the right position, the oil inlet A of the rotary motor and the oil outlet of the rotary motor are interconnected, and the free rotation function can be realized. Vice versa.

[0004] When the rotary action is switched, the pressure oil will pass through the damper 6 and then open the relief valve 8 to supply oil to the rotary motor 5. The pressure loss in the process is large, and the rotary stability is easily affected by the response characteristics of the relief valve 8. The opening of the relief valve 8 is prone to cause instantaneous impact, resulting in continuous jitter. At the same time, the damper 6 is sensitive to the cleanliness of the oil and is prone to clogging, causing rotary jitter and affecting the reliability of the system. Summary of the invention

[0005] The object of the present invention is to provide a hydraulic slewing buffer system and a crane, which can improve the stability of the slewing buffer system.

[0006] The embodiment of the present invention is achieved as follows:

[0007] One aspect of an embodiment of the present invention provides a hydraulic rotary buffer system, which includes an oil inlet, an oil return port, a rotary motor, a reversing valve, a shuttle valve and an energy storage device, the reversing valve is connected between the oil inlet, the oil return port, the oil inlet of the rotary motor and the oil outlet of the rotary motor, the shuttle valve is connected in parallel to the circuit between the reversing valve and the rotary motor, and the outlet of the shuttle valve is connected to two interconnected oil circuits, one of the oil circuits is connected to the energy storage device to store hydraulic energy in the energy storage device, and the other oil circuit can release the hydraulic energy in the energy storage device to the rotary motor.

[0008] Optionally, the energy storage device includes a proportional throttle valve and an accumulator, and the hydraulic oil drawn out from the outlet of the shuttle valve is connected to the accumulator after passing through the proportional throttle valve.

[0009] Optionally, the hydraulic oil led out by the shuttle valve is communicated with the oil inlet after passing through the electromagnetic reversing valve.

[0010] Optionally, the reversing valve is a three-position six-way reversing valve, the reversing valve having a left passage, a middle passage and a right passage that can be selectively connected, one end of the left passage of the reversing valve is connected to the oil inlet, and the other end is connected to the oil inlet of the rotary motor, one end of the right passage of the reversing valve is connected to the oil return port, and the other end is connected to the oil outlet of the rotary motor, one end of the middle passage of the reversing valve is connected to the oil inlet, and the other end is respectively connected to the oil inlet and the oil outlet of the rotary motor.

[0011] Optionally, the other end of the middle passage of the reversing valve is connected to the oil inlet of the rotary motor and the oil outlet of the rotary motor through a first one-way valve.

[0012] Optionally, a first overflow valve and a second overflow valve are connected in parallel in the circuit between the reversing valve and the rotary motor, the first overflow valve and the second overflow valve are both one-way overflow valves, the oil inlet of the rotary motor is connected to the oil outlet of the first overflow valve, and the oil outlet of the rotary motor is connected to the oil inlet of the second overflow valve.

[0013] Optionally, the oil outlet of the rotary motor and the oil return port are connected via a third one-way valve.

[0014] Another aspect of an embodiment of the present invention provides a crane, which includes the above-mentioned hydraulic slewing buffer system.

[0015] The beneficial effects of the embodiments of the present invention include:

[0016] The hydraulic slewing buffer system and crane provided by the embodiment of the present invention include an oil inlet, an oil return port, a slewing motor, a reversing valve, a shuttle valve and an energy storage device. The reversing valve is connected between the oil inlet, the oil return port, the oil inlet of the slewing motor and the oil outlet of the slewing motor. The shuttle valve is connected in parallel to the circuit between the reversing valve and the slewing motor. The outlet of the shuttle valve is connected to two oil circuits that are interconnected. One oil circuit is connected to the energy storage device. When the reversing valve is in the middle position, hydraulic energy is stored in the energy storage device. The other oil circuit can release the hydraulic energy in the energy storage device to the slewing motor at the moment of starting the slewing action. The energy storage device is set as a smooth pressure fluctuation and stop buffer, and energy recovery can be performed at the same time. The energy storage device replaces the combination of damping + overflow valve in the prior art to achieve slewing buffering, improve slewing stability, and achieve energy recovery and utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is the principle diagram of the hydraulic slewing buffer system of the existing crane;

[0019] Figure 2 A schematic diagram of a hydraulic rotary buffer system provided in an embodiment of the present invention.

[0020] Icons: 1-reversing valve; 2-check valve; 2A-first check valve; 2B-second check valve; 3-check relief valve; 3A-first relief valve; 3B-second relief valve; 4-shuttle valve; 5-swing motor; 6-damping; 7-solenoid reversing valve; 8-relief valve; 9-proportional throttle valve; 10-accumulator; 11-third check valve; A-oil inlet of the swing motor; B-oil outlet of the swing motor; P-oil inlet; T-oil return port. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0025] Please refer to Figure 2 The present embodiment provides a hydraulic rotary buffer system, which includes an oil inlet P, an oil return port T, a reversing valve 1, a first one-way valve 2A, a second one-way valve 2B, a first overflow valve 3A, a second overflow valve 3B, a shuttle valve 4, a rotary motor 5, an electromagnetic reversing valve 7 and an energy storage device, wherein the energy storage device includes a proportional throttle valve 9 and an accumulator 10.

[0026] The reversing valve 1 is a hydraulically controlled reversing valve, which is connected between the oil inlet P, the oil return port T, the oil inlet A of the rotary motor and the oil outlet B of the rotary motor. The shuttle valve 4 is connected in parallel to the circuit between the reversing valve 1 and the rotary motor 5. The outlet of the shuttle valve 4 is connected to two interconnected oil circuits, one of which is connected to the energy storage device to store hydraulic energy in the energy storage device, and the other can release the hydraulic energy in the energy storage device to the rotary motor 5.

[0027] Specifically, the energy storage device includes a proportional throttle valve 9 and an accumulator 10 . The hydraulic oil led out of the shuttle valve 4 is connected to the accumulator 10 through the proportional throttle valve 9 in one way and communicated with the oil inlet P through the electromagnetic reversing valve 7 in the other way.

[0028] like Figure 2 As shown, the shuttle valve 4 is connected to the accumulator 10 via the proportional throttle valve 9, and hydraulic energy is stored in the accumulator 10; when the hydraulic energy is released, the hydraulic energy is released from the accumulator 10 and returns to the oil inlet A of the rotary motor through the proportional throttle valve 9, the electromagnetic reversing valve 7, the oil inlet P, and the first one-way valve 2A in sequence.

[0029] The circuit between the reversing valve 1 and the rotary motor 5 is connected in parallel with a first one-way valve 2A and a second one-way valve 2B, respectively. The hydraulic oil drawn out from the oil inlet P acts on both sides of the rotary motor 5 after passing through the first one-way valve 2A and the second one-way valve 2B.

[0030] Specifically, the reversing valve 1 is a three-position six-way reversing valve, and the reversing valve 1 has a left passage, a middle passage and a right passage that can be selectively connected. One end of the left passage of the reversing valve 1 is connected to the oil inlet P, and the other end is connected to the oil inlet A of the rotary motor. One end of the right passage of the reversing valve 1 is connected to the oil return port T, and the other end is connected to the oil outlet B of the rotary motor. One end of the middle passage of the reversing valve 1 is connected to the oil inlet P, and the other end is connected to the oil inlet A and the oil outlet B of the rotary motor through the first one-way valve 2A.

[0031] The oil outlet B and the oil return port T of the rotary motor are connected via the third one-way valve 11, the oil inlet of the third one-way valve 11 is connected to the oil outlet B of the rotary motor, the oil outlet of the third one-way valve 11 is connected to the oil return port T, the hydraulic oil flows from the oil outlet B of the rotary motor through the third one-way valve 11 to the oil return port T, the setting of the third one-way valve 11 prevents the hydraulic oil in the oil return port T from flowing back to the oil outlet B of the rotary motor.

[0032] The first overflow valve 3A and the second overflow valve 3B are installed in parallel in reverse in the circuit between the reversing valve 1 and the rotary motor 5. The first overflow valve 3A and the second overflow valve 3B are both one-way overflow valves. The oil inlet A of the rotary motor is connected to the oil outlet of the first overflow valve 3A, and the oil outlet of the rotary motor 5 is connected to the oil inlet of the second overflow valve 3B.

[0033] When the hydraulic rotary buffer system provided in this embodiment is working, when the rotary handle transitions to the middle position of the reversing valve 1, the rotary motor 5 will continue to operate due to the effect of inertia. At this time, the pressure of the oil outlet B of the rotary motor increases sharply. At this time, a part of the hydraulic oil passes through the second relief valve 3B and the first relief valve 3A in sequence to supply oil to the rotary motor 5, and the other part of the hydraulic oil passes through the shuttle valve 4 and then enters the accumulator 10, storing the inertial impact force energy of the rotary stop in the accumulator 10, making the rotary stop softer and more stable.

[0034] When the swing action starts, the hydraulic oil of the oil pump drives the swing motor 5, which will have a certain loss along the way and response time. At this time, the energy stored in the accumulator 10 will be released through the electric proportional throttle valve 9 to drive the swing motor 5, making the swing response faster. At the same time, due to the softness of the energy release of the accumulator 10 itself, the swing start moment is more stable than the throttle oil supply.

[0035] The working principle of the hydraulic rotary buffer system provided in this embodiment is: when there is no electrical signal in the proportional throttle valve 9, the proportional throttle valve 9 can be used as a one-way valve, filled with fluid in one direction, and used as a stop buffer; during the rotary operation, the electrical signal controls the proportional throttle valve 9, and fills and discharges fluid in two directions to stabilize the system pressure, making the rotary start and rotary process smoother.

[0036] The hydraulic rotary buffer system provided in this embodiment can recover energy by setting an accumulator 10 as a pressure fluctuation smoothing and stop buffer. The stability of the rotation is achieved by the combined action of the accumulator 10 and the electronically controlled liquid-filled proportional throttle valve 9. The combination of the electric proportional throttle valve 9 + accumulator 10 is used to replace the combination of the damping 6 + overflow valve 8 in the prior art to achieve rotary buffering, improve rotary stability, and achieve energy recovery and utilization, so that the system's sensitivity to the cleanliness of the oil is greatly reduced, while avoiding the influence of the response performance of the overflow valve 8 on the rotary stability. The hydraulic rotary buffer system has the characteristics of high reliability and easy maintenance.

[0037] The embodiment of the present invention further discloses a crane, comprising any one of the above-mentioned hydraulic slewing buffer systems. The crane comprises the same structure and beneficial effects as the hydraulic slewing buffer system in the above-mentioned embodiment. The structure and beneficial effects of the hydraulic slewing buffer system have been described in detail in the above-mentioned embodiment, and will not be repeated here.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hydraulic rotary buffer system, characterized in that: The invention comprises an oil inlet (P), an oil return port (T), a rotary motor (5), a reversing valve (1), a shuttle valve (4) and an energy storage device, wherein the reversing valve (1) is connected between the oil inlet (P), the oil return port (T), the oil inlet (A) of the rotary motor and the oil outlet (B) of the rotary motor, the shuttle valve (4) is connected in parallel to a circuit between the reversing valve (1) and the rotary motor (5), and the outlet of the shuttle valve (4) is connected to two oil circuits that are interconnected, one of which is connected to the energy storage device to store hydraulic energy in the energy storage device, and the other of which can release the hydraulic energy in the energy storage device to the rotary motor (5); The energy storage device comprises a proportional throttle valve (9) and an accumulator (10); the hydraulic oil drawn out from the outlet of the shuttle valve (4) is connected to the accumulator (10) after passing through the proportional throttle valve (9); the hydraulic oil drawn out from the shuttle valve (4) is connected to the oil inlet (P) after passing through the electromagnetic reversing valve (7); A first overflow valve (3A) and a second overflow valve (3B) are connected in parallel in the circuit between the reversing valve (1) and the rotary motor (5); the first overflow valve (3A) and the second overflow valve (3B) are both one-way overflow valves; the oil inlet (A) of the rotary motor is connected to the oil outlet of the first overflow valve (3A); and the oil outlet (B) of the rotary motor is connected to the oil inlet of the second overflow valve (3B); When the rotary handle transitions to the middle position of the reversing valve (1), the rotary motor (5) will continue to operate due to the effect of inertia, and the pressure at the oil outlet B of the rotary motor will increase sharply. A part of the hydraulic oil will pass through the second relief valve and the first relief valve in sequence to supply oil to the rotary motor (5), and the other part of the hydraulic oil will pass through the shuttle valve (4) and enter the accumulator (10), and the inertial impact force energy of the stopped rotation will be stored in the accumulator (10).

2. The hydraulic rotary buffer system according to claim 1, characterized in that: The reversing valve (1) is a three-position six-way reversing valve, and the reversing valve (1) has a left passage, a middle passage and a right passage that can be selectively connected. One end of the left passage of the reversing valve is connected to the oil inlet (P), and the other end is connected to the oil inlet (A) of the rotary motor. One end of the right passage of the reversing valve is connected to the oil return port (T), and the other end is connected to the oil outlet (B) of the rotary motor. One end of the middle passage of the reversing valve (1) is connected to the oil inlet (P), and the other end is connected to the oil inlet (A) of the rotary motor and the oil outlet (B) of the rotary motor.

3. The hydraulic rotary buffer system according to claim 2, characterized in that: The other end of the central passage of the reversing valve (1) is connected to the oil inlet (A) of the rotary motor and the oil outlet (B) of the rotary motor through a first one-way valve (2A).

4. The hydraulic rotary buffer system according to claim 1, characterized in that: The oil outlet (B) of the rotary motor and the oil return port (T) are connected via a third one-way valve (11).

5. A crane, characterized in that: It comprises a hydraulic rotary buffer system as described in any one of claims 1 to 4.

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