Pressure reducing electric proportional relief valve, mechanical equipment and fall range control method

Abstract

The application discloses a pressure reducing electric proportional overflow valve, a mechanical device and a falling range control method, and relates to the technical field of electric proportional overflow valves.The pressure reducing electric proportional overflow valve comprises a pressure reducing valve and an electric proportional valve.The pressure reducing valve is connected with a main oil circuit of a variable amplitude oil cylinder.The pressure reducing valve comprises a connecting assembly and an adjusting piece.The connecting assembly has an adjusting space inside.The adjusting piece is movably arranged in the adjusting space.An elastic piece is arranged in the adjusting space.A pressure relief cavity is formed between the adjusting piece and the main oil circuit.The electric proportional valve is arranged on two opposite sides of the pressure reducing valve relative to the main oil circuit.When the oil pressure of the main oil circuit is within a set threshold value, the electric proportional valve is in a first state, the oil inlet is in communication with the oil outlet, when the oil pressure of the main oil circuit is higher than the set threshold value, the electric proportional valve is switched to a second state, the oil inlet is disconnected from the oil outlet, the oil inlet is in communication with the pressure relief cavity, and during the process of the oil pressure of the main oil circuit decreasing, the electric proportional valve is switched to a third state, the oil inlet is disconnected from the oil outlet and the pressure relief cavity, and the pressure relief cavity is in communication with the oil outlet.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric proportional relief valves, and more particularly to a pressure-reducing electric proportional relief valve, a mechanical device and a luffing control method. BACKGROUND

[0002] The engineering machinery adopts a hydraulic control pilot handle to control the luffing speed of the crane, which is controlled by the pilot oil provided by the pilot handle. The luffing speed of the boom is directly embodied by the movement speed of the luffing cylinder. The boom is supported by the luffing cylinder, and the weight of the boom acts entirely on the luffing cylinder. The boom luffing generally adopts a self-weight luffing mode. In the actual operation process, the operator controls the pilot handle to control the luffing speed of the boom. The adjustment of the luffing speed is very challenging to the operation skills of the operator. Improper operation can easily cause the boom to be unable to luff or luff too fast.

[0003] Therefore, it is necessary to provide a new technical solution to improve the oil pressure stability of the luffing cylinder. SUMMARY

[0004] An object of the present application is to provide a new technical solution of a pressure-reducing electric proportional relief valve.

[0005] According to a first aspect of the present application, a pressure reducing electric proportional overflow valve is provided for a luffing cylinder, the pressure reducing electric proportional overflow valve comprising a pressure reducing valve and an electric proportional valve; the pressure reducing valve is connected with a main oil passage of the luffing cylinder, the pressure reducing valve comprises a connecting assembly and an adjusting member, the connecting assembly has an adjusting space therein, the adjusting member is movably arranged in the adjusting space, an elastic member is arranged in the adjusting space, the elastic member is located between the adjusting member and an inner wall of the adjusting space, and the elastic member can elastically deform along an axial direction of the adjusting space, a pressure relief cavity is formed in the adjusting space and between the adjusting member and the main oil passage, the connecting assembly has an oil inlet and an oil outlet, and an end of the connecting assembly away from the oil inlet is in communication with the main oil passage; the electric proportional valve is arranged on two opposite sides of the connecting assembly and in communication with the main oil passage, the electric proportional valve has a first state, a second state and a third state, wherein, when an oil pressure in the main oil passage is within a set threshold, the electric proportional valve is in the first state, the oil inlet is in communication with the oil outlet, the pressure relief cavity is disconnected from the oil inlet, when the oil pressure in the main oil passage is higher than the set threshold, the electric proportional valve is switched to the second state, the oil inlet is disconnected from the oil outlet, and the oil inlet is in communication with the pressure relief cavity, based on an increase in liquid pressure in the pressure relief cavity, the adjusting member moves from the main oil passage to the electric proportional valve, during a decrease in the oil pressure in the main oil passage, the electric proportional valve is switched to the third state, the oil inlet is disconnected from the oil outlet and the pressure relief cavity, and the pressure relief cavity is in communication with the oil outlet, based on a decrease in the liquid pressure in the pressure relief cavity and a deformation force of the elastic member, the adjusting member moves from the electric proportional valve to the main oil passage.

[0006] Optionally, the connecting assembly comprises a screw plug and a screw plug sleeve; the screw plug is provided with a connecting groove, the oil inlet and the oil outlet are in communication with the connecting groove, the electric proportional valve is embedded in the connecting groove, and the oil inlet and the oil outlet are in communication through the electric proportional valve; the screw plug sleeve is arranged on a side of the screw plug away from the electric proportional valve, the screw plug sleeve has the adjusting space, and the screw plug sleeve is provided with a gas vent in communication with the adjusting space.

[0007] Optionally, a protruding portion is arranged on a side of the screw plug away from the electric proportional valve, the protruding portion is embedded in the adjusting space, and a first sealing member is arranged between an outer wall of the protruding portion and an inner wall of the screw plug sleeve.

[0008] Optionally, the screw plug sleeve has a first end and a second end, the first end and the second end are respectively located at opposite sides of the adjusting space, an inner diameter of the first end is matched with an inner diameter of the adjusting space, an inner diameter of the second end is smaller than the inner diameter of the first end, the first end is connected with the screw plug, and the second end is connected with the main oil passage.

[0009] Optionally, the adjusting member includes a spring seat, the spring seat is arranged in the adjusting space, one end of the spring seat has a connecting rod, the connecting rod is movably arranged in the adjusting space, the elastic member is sleeved on the connecting rod, and opposite ends of the elastic member are respectively in abutment with the screw plug and a side wall of the spring seat.

[0010] Optionally, a side of the spring seat away from the connecting rod has an embedded part, a diameter of the embedded part is matched with the inner diameter of the second end, the embedded part is embedded in a cavity of the second end, a second sealing member is arranged between an outer wall of the embedded part and an inner wall of the cavity, a third sealing member is arranged between an outer wall of the spring seat and an inner wall of the adjusting space, and the spring seat, the third sealing member, the screw plug sleeve and the second sealing member enclose the pressure relief cavity.

[0011] Optionally, the screw plug has an oil pressure port, the oil inlet and the pressure relief cavity are communicated through the oil pressure port.

[0012] Optionally, the connecting rod has an oil channel, the oil channel is opened along an axial extension direction of the connecting rod, and the oil pressure port and the pressure relief cavity are communicated through the oil channel.

[0013] According to a second aspect of the present application, a mechanical device is provided, the mechanical device applies the pressure relief electric proportional overflow valve as described above, and the mechanical device includes the luffing oil cylinder, and the pressure relief electric proportional overflow valve is communicated with the main oil passage of the luffing oil cylinder.

[0014] According to a third aspect of the present application, a fall range control method is provided, which is applied to the pressure reducing electric proportional overflow valve as described above, the pressure reducing electric proportional valve switches among the first state, the second state and the third state according to the oil pressure of the main oil path; the variable range oil cylinder is connected with the electric proportional valve, when the oil pressure of the main oil path is within a set threshold, the electric proportional valve is in the first state, the adjusting member is located at the side of the adjusting space close to the main oil path, the oil inlet is communicated with the oil outlet; when the oil pressure of the main oil path is higher than the set threshold, the electric proportional valve switches to the second state, the oil inlet is disconnected with the oil outlet, and the oil inlet is communicated with the pressure relief cavity, the oil enters the pressure relief cavity through the oil inlet, based on the increase of the liquid pressure in the pressure relief cavity, the adjusting member moves in the adjusting space from the direction of the electric proportional valve to the main oil path, and the elastic member is gradually compressed, the space of the main oil path increases, and the liquid pressure gradually decreases; during the decrease of the oil pressure of the main oil path, the electric proportional valve switches to the third state, the oil inlet is disconnected with the oil outlet and the pressure relief cavity respectively, and the pressure relief cavity is communicated with the oil outlet, the oil in the pressure relief cavity flows to the oil tank through the oil outlet, the liquid pressure in the pressure relief cavity gradually decreases, and the adjusting member moves in the adjusting space from the direction of the electric proportional valve to the main oil path by the deformation force of the elastic member; when the oil pressure of the main oil path decreases to the range of the set threshold, the adjusting member is located at the side of the adjusting space close to the main oil path, the electric proportional valve switches to the first state, and the electric proportional valve is powered off.

[0015] In the embodiment of the present application, the pressure reducing valve is matched with the electric proportional valve to switch the pressure reducing electric proportional overflow valve between the first state, the second state and the third state, so as to adjust the oil pressure of the main oil way. When the oil pressure of the main oil way is in the normal threshold range, the electric proportional valve is in the first state, the adjusting part is located at the side close to the main oil way in the adjusting space, and the oil inlet is communicated with the oil outlet, so that the oil pressure of the main oil way does not need to be adjusted. When the oil pressure of the main oil way is higher than the set threshold, the electric proportional valve is in the second state, the electric proportional valve is powered on to disconnect the oil inlet from the oil outlet and to communicate the oil inlet with the pressure relief cavity, so that the oil enters the pressure relief cavity through the oil inlet, the adjusting part is moved from the main oil way to the electric proportional valve by the oil in the pressure relief cavity, so that the space of the main oil way is increased and the oil pressure is reduced. During the reduction of the oil pressure of the main oil way, the electric proportional valve is in the third state, the oil inlet is disconnected from the oil outlet and the pressure relief cavity, and the oil outlet is communicated with the pressure relief cavity, so that the oil in the pressure relief cavity flows back to the tank through the oil outlet, and the adjusting part is moved from the electric proportional valve to the main oil way by the tension of the elastic part. When the oil pressure in the main oil way recovers to the set threshold range, the electric proportional valve switches to the first state, the pressure relief cavity is disconnected from the oil inlet and the oil outlet, and the oil inlet is communicated with the oil outlet, so that the oil pressure of the main oil way is adjusted by switching the electric proportional valve between the first state, the second state and the third state, the oil pressure stability of the main oil way of the variable amplitude oil cylinder is effectively enhanced, the micro-motion performance of the variable amplitude oil cylinder is improved, and the falling amplitude stability of the crane boom is improved.

[0016] Other features and advantages of the present application will become apparent from the following detailed description of illustrative embodiments thereof, which proceeds with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0018] Figure 1 is a structural schematic view of the pressure reducing electric proportional overflow valve in the embodiment of the present application;

[0019] Figure 2 is a top view of the pressure reducing electric proportional overflow valve in the embodiment of the present application;

[0020] Figure 3 is Figure 2 is a sectional view of A-A in FIG. 4;

[0021] Figure 4 is Figure 3 is an enlarged schematic view of the circled part in FIG. 4;

[0022] Figure 5 is a structural schematic view of the screw plug in the embodiment of the present application;

[0023] Figure 6 is a structural schematic diagram of a screw plug sleeve in the embodiment of the present application;

[0024] Figure 7 is a structural schematic diagram of an adjusting member in the embodiment of the present application.

[0025] Legend:

[0026] 1 - pressure reducing valve;

[0027] 11 - connecting assembly; 111 - screw plug; 112 - connecting groove; 113 - screw plug sleeve; 114 - protrusion; 115 - oil pressure port; 116 - cavity;

[0028] 12 - adjusting member; 121 - spring seat; 122 - connecting rod; 123 - oil passage; 124 - embedding portion;

[0029] 13 - adjusting space; 131 - pressure relief cavity;

[0030] 14 - oil inlet;

[0031] 15 - oil outlet;

[0032] 16 - air outlet;

[0033] 17 - elastic member;

[0034] 2 - electric proportional valve;

[0035] 3 - main oil path. DETAILED DESCRIPTION

[0036] Various exemplary embodiments of the present application will now be described in detail with reference to the figures. It should be noted that the relative arrangements, numerical expressions, and values of the components and steps set forth in these embodiments are not limiting to the scope of the present application unless specifically stated otherwise.

[0037] The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the application or its application or uses.

[0038] Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail herein. However, where appropriate, techniques, methods, and devices should be considered part of the description of the present application.

[0039] In all of the compositions and methods shown and discussed herein, any specific values should be interpreted as merely exemplary, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values.

[0040] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0041] According to one embodiment of this application, a pressure-reducing electro-proportional relief valve is provided for use in a variable amplitude cylinder. The pressure-reducing electro-proportional relief valve includes a pressure-reducing valve 1 and an electro-proportional valve 2. The pressure-reducing valve 1 is connected to the main oil circuit 3 of the luffing cylinder. The pressure-reducing valve 1 includes a connecting assembly 11 and an adjusting member 12. The connecting assembly 11 has an adjusting space 13. The adjusting member 12 is movably disposed within the adjusting space 13. An elastic member 17 is disposed within the adjusting space 13. The elastic member 17 is located between the adjusting member 12 and the inner wall of the adjusting space 13, and the elastic member 17 can elastically deform along the axial direction of the adjusting space 13. A pressure relief chamber 131 is formed within the adjusting space 13 and between the adjusting member 12 and the main oil circuit 3. The connecting assembly 11 has an oil inlet 14 and an oil outlet 15. The end of the connecting assembly 11 opposite to the oil inlet 14 is connected to the main oil circuit 3. The electro-proportional valve 2 and the main oil circuit 3 are disposed on opposite sides of the connecting assembly 11. The electro-proportional valve 2 has a first state. The system comprises three states: a second state and a third state. When the oil pressure in the main oil circuit 3 is within a set threshold, the electro-proportional valve 2 is in the first state, with the inlet 14 connected to the outlet 15 and the pressure relief chamber 131 disconnected from the inlet 14. When the oil pressure in the main oil circuit 3 is higher than the set threshold, the electro-proportional valve 2 switches to the second state, with the inlet 14 disconnected from the outlet 15 and connected to the pressure relief chamber 131. The end of the elastic element 17 near the adjusting element 12 moves from the main oil circuit 3 towards the electro-proportional valve 2. During the decrease in oil pressure in the main oil circuit 3, the electro-proportional valve 2 switches to the third state, with the inlet 14 disconnected from both the outlet 15 and the pressure relief chamber 131, and the pressure relief chamber 131 connected to the outlet 15. The end of the elastic element 17 near the adjusting element 12 moves from the electro-proportional valve 2 towards the main oil circuit 3.

[0042] like Figures 1 to 7 As shown, the electro-proportional valve 2 is connected to the main oil circuit 3 of the luffing cylinder through the pressure reducing valve 1. When the oil pressure of the main oil circuit 3 is at the normal threshold, the oil pressure of the main oil circuit 3 does not need to be adjusted, the electro-proportional valve 2 is not energized, and the adjusting element 12 of the pressure reducing valve 1 is located on the side closer to the main oil circuit 3. When the oil pressure of the main oil circuit 3 exceeds the set threshold, the electro-proportional valve 2 is energized to drive the adjusting element 12 of the pressure reducing valve 1 to move away from the main oil circuit 3, thereby reducing the oil pressure of the main oil circuit 3, realizing uniform crane descent speed and improving descent stability.

[0043] The pressure relief valve 1 comprises a connecting assembly 11 and an adjusting part 12, the adjusting space 13 in the connecting assembly 11 is cylindrical, one end of the connecting assembly 11 is connected with the electric proportional valve 2, and the other end of the connecting assembly 11 is connected with the main oil circuit 3. The oil inlet 14 and the oil outlet 15 on the connecting assembly 11 are arranged on the side of the connecting assembly 11 close to the electric proportional valve 2, and the oil inlet 14 and the oil outlet 15 can be switched between the first state, the second state and the third state through the electric proportional valve 2 to realize the on and off through the conduction interface of the electric proportional valve 2.

[0044] The adjusting part 12 is arranged in the adjusting space 13, the elastic part 17 is a spring, the spring is arranged in the adjusting space 13 and can move in the axial direction of the adjusting space 13.

[0045] When the oil pressure of the main oil circuit 3 is in the set threshold range, the electric proportional valve 2 is in the first state, in the first state, the electric proportional valve 2 is not electrified, the adjusting part 12 is located at one end of the adjusting space 13 close to the main oil circuit 3, and the oil inlet 14 and the oil outlet 15 are in conduction, and the pressure relief cavity 131 is not in conduction with the oil inlet 14 and the oil outlet 15.

[0046] When the oil pressure of the main oil circuit 3 is higher than the set threshold, the electric proportional valve 2 is in the second state, in the second state, the electric proportional valve 2 is electrified, the oil inlet 14 and the oil outlet 15 are disconnected, the oil inlet 14 is in conduction with the pressure relief cavity 131, the oil enters the pressure relief cavity 131 through the oil inlet 14, and the oil entering the pressure relief cavity 131 pushes the adjusting part 12 to move from the main oil circuit 3 to the electric proportional valve 2, so that the space of the main oil circuit 3 increases, and the oil pressure of the main oil circuit 3 is adjusted.

[0047] When the oil pressure of the main oil circuit 3 decreases and gradually recovers to the set value range, the electric proportional valve 2 is in the third state, in the third state, the electric proportional valve 2 is electrified, the oil inlet 14 is disconnected with the oil outlet 15 and the pressure relief cavity 131, and the oil outlet 15 and the pressure relief cavity 131 are in conduction, the oil in the pressure relief cavity 131 flows to the oil tank through the oil outlet 14, in the process, the adjusting part 12 is pushed by the elastic part 17 to move from the electric proportional valve 2 to the main oil circuit 3, so that the adjusting part 12 moves to the side of the adjusting space 13 close to the main oil circuit 3.

[0048] Through the switching of the electric proportional valve 2 between the first state, the second state and the third state, the pressure relief valve 1 adjusts the oil pressure of the main oil circuit 3, so that the falling range of the crane is uniform, and the stability of the falling range is improved.

[0049] Of course, the pressure relief electric proportional overflow valve in the embodiment of the present application is not limited to the above-mentioned scene, and those skilled in the art can set it according to actual needs. For example, it can also be applied to important industrial fields such as aviation, aerospace, weapon equipment, steel and power station.

[0050] In the embodiment of the present application, the pressure reducing valve 1 cooperates with the electric proportional valve 2 to switch the pressure reducing electric proportional overflow valve between the first state, the second state and the third state, so as to adjust the oil pressure of the main oil circuit 3. When the oil pressure of the main oil circuit 3 is within the normal threshold range, the electric proportional valve 2 is in the first state, the adjusting part 12 is located at the side of the adjusting space 13 close to the main oil circuit 3, the oil inlet 14 and the oil outlet 15 are in communication, and the oil pressure of the main oil circuit 3 does not need to be adjusted. When the oil pressure of the main oil circuit 3 is higher than the set threshold, the electric proportional valve 2 is in the second state, the electric proportional valve 2 is energized to disconnect the oil inlet 14 and the oil outlet 15, and connect the oil inlet 14 and the pressure relief cavity 131, so that the oil enters the pressure relief cavity 131 through the oil inlet 14, and the oil in the pressure relief cavity 131 pushes the adjusting part 12 to move from the main oil circuit 3 to the electric proportional valve 2, so that the space of the main oil circuit 3 increases and the oil pressure decreases. During the decrease of the oil pressure of the main oil circuit 3, the electric proportional valve 2 is in the third state, the oil inlet 14 is disconnected with the oil outlet 15 and the pressure relief cavity 131, and the oil outlet 15 is connected with the pressure relief cavity 131, so that the oil in the pressure relief cavity 131 returns to the oil tank through the oil outlet 15, and the elastic part 17 pushes the adjusting part 12 to move from the electric proportional valve 2 to the main oil circuit 3. When the oil pressure in the main oil circuit 3 returns to the set threshold range, the electric proportional valve 2 switches to the first state, the pressure relief cavity 131 is disconnected with the oil inlet 14 and the oil outlet 15, and the oil inlet 14 is connected with the oil outlet 15. By switching the electric proportional valve 2 between the first state, the second state and the third state to adjust the oil pressure of the main oil circuit 3, the stability of the oil pressure of the main oil circuit 3 of the variable amplitude cylinder is effectively enhanced, and the micro-motion performance of the variable amplitude cylinder is improved, and the falling amplitude stability of the mechanical equipment is improved.

[0051] In one example, the connecting assembly 11 includes a screw boss 111 and a screw boss sleeve 113. The screw boss 111 is provided with a connecting groove 112, the oil inlet 14 and the oil outlet 15 are in communication with the connecting groove 112, the electric proportional valve 2 is embedded in the connecting groove 112, and the oil inlet 14 and the oil outlet 15 are in communication through the electric proportional valve 2. The screw boss sleeve 113 is arranged on the side of the screw boss 111 away from the electric proportional valve 2, the screw boss sleeve 113 has the adjusting space 13, and the screw boss sleeve 113 is provided with a gas vent 16 in communication with the adjusting space 13.

[0052] As Figures 1 to 7As shown, the opposite ends of the screw plug 111 are connected with the electric proportional valve 2 and the screw plug sleeve 113 respectively, the end of the screw plug 111 close to the electric proportional valve 2 has a connecting groove 112, the electric proportional valve 2 is embedded in the connecting groove 112, and the on-off interface on the electric proportional valve 2 corresponds to the oil inlet 14 and the oil outlet 15 on the screw plug 111, the oil inlet 14 and the oil outlet 15 are turned on and turned off by switching the electric proportional valve 2 between the first state, the second state and the third state.

[0053] As shown in the figure, Figures 5 to 6 The screw plug sleeve 113 is arranged at the end of the screw plug 111 away from the electric proportional valve 2, the adjusting space 13 in the screw plug sleeve 113 is provided with an adjusting piece 12, the adjusting piece 12 can move in the axial direction of the adjusting space 13, and a pressure relief cavity 131 is formed at the end of the adjusting space 13 away from the screw plug 111, when the oil pressure of the main oil circuit 3 is higher than the set threshold value, the pressure relief cavity 131 communicates with the oil inlet 14, and the adjusting piece 12 is pushed by the oil liquid in the pressure relief cavity 131 to move from the main oil circuit 3 to the electric proportional valve 2. The side of the screw plug sleeve 113 close to the pressure relief cavity 131 communicates with the main oil circuit 3.

[0054] When the oil pressure of the main oil circuit 3 is higher than the set value, the electric proportional valve 2 is in the second state, the electric proportional valve 2 is powered on, the oil inlet 14 is communicated with the pressure relief cavity 131, the oil liquid enters the pressure relief cavity 131 through the oil inlet 14, and the adjusting piece 12 is pushed to move from the main oil circuit 3 to the electric proportional valve 2, thereby increasing the space of the main oil circuit 3 and reducing the pressure of the main oil circuit 3, when the oil pressure in the main oil circuit 3 gradually decreases, the electric proportional valve 2 switches to the third state, the oil outlet 15 is communicated with the pressure relief cavity 131, the oil inlet 14 is in the off state with the oil outlet 15 and the pressure relief cavity 131, the adjusting piece 12 moves from the electric proportional valve 2 to the main oil circuit 3, the oil liquid in the pressure relief cavity 131 returns to the oil tank through the air outlet 16, until the oil pressure in the main oil circuit 3 returns to the set threshold value, the adjusting piece 12 is located at the side of the adjusting space 13 close to the main oil circuit 3, effectively adjusting the oil pressure stability of the main oil circuit 3, so that the falling range of the crane is uniform, and the falling range stability is improved.

[0055] The air outlet 16 is arranged on the screw plug sleeve 113, and the air outlet 16 communicates with the adjusting space 13, by arranging the air outlet 16 on the screw plug sleeve 113 which communicates with the adjusting space 13, when the spring seat 121 moves in the adjusting space 13, the gas in the adjusting space 13 flows, avoiding the adjusting space 13 becoming a dead space, affecting the adjusting effect of the pressure reducing valve 1

[0056] In one example, the side of the screw plug 111 away from the electric proportional valve 2 has a protruding part 114, the protruding part 114 is embedded in the adjusting space 13, and the first sealing piece is arranged between the outer wall of the protruding part 114 and the inner wall of the screw plug sleeve 113.

[0057] As shown in Figures 1 to 7 The side of the screw plug 111 has a protruding part 114, the outer diameter of the protruding part 114 is matched with the inner diameter of the adjusting space 13, the screw plug sleeve 113 is arranged on the protruding part 114, and the protruding part 114 and the screw plug sleeve 113 are provided with a check ring and a first sealing element. The check ring can effectively improve the connection strength between the screw plug 111 and the screw plug sleeve 113, and the first sealing element can prevent oil leakage during oil pressure adjustment to cause damage to the equipment.

[0058] The first sealing element and the check ring can be made of rubber, silicone or the like.

[0059] In one example, the screw plug sleeve 113 has a first end and a second end, the first end and the second end are respectively located at opposite sides of the adjusting space 13, the inner diameter of the first end is matched with the inner diameter of the adjusting space 13, the inner diameter of the second end is smaller than the inner diameter of the first end, the first end is connected with the screw plug 111, and the second end is connected with the main oil way 3.

[0060] As shown in Figures 1 to 7 The screw plug sleeve 113 has a first end and a second end. The outer diameter of the first end of the screw plug sleeve 113 is larger than the outer diameter of the second end of the screw plug sleeve 113, and the inner diameter of the first end of the screw plug sleeve 113 is larger than the inner diameter of the second end of the screw plug sleeve 113. The inner diameter of the adjusting space 13 is larger than the inner diameter of the second end. The inner diameter of the first end is matched with the inner diameter of the adjusting space 13.

[0061] By embedding the end of the screw plug 111 in the first end of the screw plug sleeve 113, and setting the diameter of the second end of the screw plug sleeve 113 to be smaller than the diameter of the first end, the holes at the two opposite sides of the adjusting space 13 are smaller than the diameter of the spring seat 121, so as to limit the movement space of the spring seat 121 and adjust the oil pressure of the main oil way 3.

[0062] The first end of the screw plug sleeve 113 is connected with the protruding part 114 of the screw plug 111, that is, the protruding part 114 of the screw plug 111 is embedded in the first end, and abuts against the spring. By embedding the protruding part 114 in the first end, not only the connection strength of the screw plug 111 and the screw plug sleeve 113 can be effectively enhanced, but also the spring seat 121 and the connecting rod 122 can be moved in the adjusting space 13 by the spring to adjust the oil pressure of the main oil way 3.

[0063] Of course, the screw plug 111 and the screw plug sleeve 113 are not limited to the above structure in the embodiments of the present application, and those skilled in the art can set them according to actual needs. For example, the screw plug 111 and the screw plug sleeve 113 are an integral structure, and the adjusting space 13 for placing the adjusting element 12 and the elastic element 17 is formed in the screw plug 111 and the screw plug sleeve 113.

[0064] In one example, the adjusting member 12 includes a spring seat 121 and an elastic member 17. The spring seat 121 is disposed within the adjusting space 13. One end of the spring seat 121 has a connecting rod 122. The connecting rod 122 is movably disposed within the adjusting space 13. The elastic member 17 is sleeved on the connecting rod 122, and the opposite ends of the elastic member 17 abut against the screw plug 111 and the side wall of the spring seat 121, respectively.

[0065] like Figures 1 to 7 As shown, the elastic element 17 is a spring. The adjusting element 12 includes a spring seat 121 and a spring. Both the spring seat 121 and the spring are disposed in the adjusting space 13. The adjusting space 13 is cylindrical, the spring seat 121 is circular plate-shaped, and a connecting rod 122 is disposed on the side of the spring seat 121 near the electro-proportional valve 2. The connecting rod 122 is cylindrical.

[0066] The end of the screw plug 111 embedded in the screw plug sleeve 113 has a groove communicating with the adjustment space 13. One end of the connecting rod 122 is fixedly connected to the spring seat 121, and the other end of the connecting rod 122 is embedded in the groove. A fourth sealing element is provided between the outer wall of the connecting rod 122 and the inner wall of the groove. The fourth sealing element can be made of materials such as rubber or silicone.

[0067] A spring sleeve is mounted on the connecting rod 122, with one end of the spring abutting against the end of the screw plug 111 and the other end of the spring abutting against the side wall of the spring seat 121. The side of the spring seat 121 facing away from the connecting rod 122 and the screw plug 111 form a pressure relief chamber 131 within the adjustment space 13.

[0068] When the oil pressure in the main oil circuit 3 is higher than the set threshold, the electro-proportional valve 2 is in the second state. The electro-proportional valve 2 is energized, and the oil inlet 14 is connected to the pressure relief chamber 131. The oil enters the pressure relief chamber 131 through the oil inlet 14, pushing the regulating component 12 to move from the main oil circuit 3 toward the electro-proportional valve 2, thereby reducing the pressure in the main oil circuit 3.

[0069] When the oil pressure in the main oil circuit 3 gradually decreases, the electro-proportional valve 2 is in the third state, with the oil inlet 14 disconnected from the pressure relief chamber 131 and the oil drain port 15. The pressure relief chamber 131 and the oil drain port 15 are connected, and the oil in the pressure relief chamber 131 flows back to the oil tank through the oil drain port 15. The spring seat 121 moves from the electro-proportional valve 2 toward the main oil circuit 3 by the spring until the adjusting member 12 moves to the side of the adjusting space 13 closer to the main oil circuit 3. The oil pressure in the main oil circuit 3 recovers to the set threshold range, and the electro-proportional valve 2 switches to the first state. The electro-proportional valve 2 is not energized. By switching the bracket between the first, second, and third states of the electro-proportional valve 2, the oil pressure in the main oil circuit 3 is stabilized, so that the crane's drop is uniform and the drop stability is improved.

[0070] In the embodiment of the present application, the oil passage 123 can be formed on the connecting rod 122, so that the oil inlet 14 is in communication with the pressure relief cavity 131.

[0071] Of course, in the embodiment of the present application, the oil inlet 14 and the pressure relief cavity 131 are not limited to the above structure, and a person skilled in the art can set them according to actual needs. For example, the oil passage 123 can be formed on the gland 111 and the gland sleeve 113, so that the oil inlet 14 is in communication with the pressure relief cavity 131 through the oil passage 123.

[0072] As shown in Figure 3 , the diameter of the spring seat 121 is larger than the diameter of the connecting rod 122, so that the force receiving areas of the two opposite sides of the adjusting member 12 are different, that is, the force receiving area of the side of the adjusting member 12 close to the oil inlet 14 is smaller than the force receiving area of the side of the adjusting member 12 close to the pressure relief cavity 131. Through this design, when the oil enters the pressure relief cavity 131 through the oil passage 123, the force of the adjusting member 12 in the direction from the electric proportional valve 2 to the main oil path 3 can be reduced, and since the force receiving area of the spring seat 121 is larger than the force receiving area of the connecting rod 122, it is beneficial to push the spring seat 121 to move in the direction from the main oil path 3 to the electric proportional valve 2 by the oil pressure in the pressure relief cavity 131.

[0073] In one example, the side of the spring seat 121 away from the connecting rod 122 has an embedded part 124, the diameter of the embedded part 124 is matched with the inner diameter of the second end, the embedded part 124 is embedded in the cavity 116 of the second end, a second sealing member is arranged between the outer wall of the embedded part 124 and the inner wall of the cavity 116, a third sealing member is arranged between the outer wall of the spring seat 121 and the inner wall of the adjusting space 13, and the spring seat 121, the third sealing member, the gland sleeve 113 and the second sealing member enclose to form the pressure relief cavity 131.

[0074] As shown in Figures 1 to 7 , the spring seat 121 is a circular plate, is arranged in the adjusting space 13, and can move in the axial direction of the adjusting space 13. An embedded part 124 is arranged on the side of the spring seat 121 away from the connecting rod 122, the diameter of the embedded part 124 is matched with the inner diameter of the second end, and a second sealing member is arranged between the outer wall of the embedded part 124 and the inner wall of the second end. A fourth sealing member is arranged between the outer wall of the spring seat 121 and the inner wall of the adjusting space 13, and the second sealing member and the fourth sealing member can be made of rubber, silicone or the like.

[0075] By providing a fourth seal between the outer wall of the spring seat 121 and the inner wall of the adjusting space 13, and a second seal between the outer wall of the mounting portion 124 and the inner wall of the second end, the spring seat 121, the screw plug 113, and the mounting portion 124 enclose a pressure relief chamber 131. The pressure relief chamber 131 is connected to the oil passage 123, allowing oil to flow into the pressure relief chamber 131 through the oil inlet 14 and the oil passage 123, thereby pushing the spring seat 121 to move from the main oil circuit 3 towards the electro-proportional valve 2, and effectively reducing the risk of oil leakage.

[0076] In one example, the plug 111 has an oil pressure port 115, through which the oil inlet 14 and the pressure relief chamber 131 are connected.

[0077] like Figures 1 to 7 As shown, the hydraulic port 115 is located on the plug 111 and connects the oil inlet 14 and the oil passage 123. When oil enters through the oil inlet 14, the oil enters the hydraulic port 115 and the oil passage 123, generating corresponding oil pressure. The oil then enters the pressure relief chamber 131 through the oil passage 123 on the connecting rod 122. The increased liquid pressure in the pressure relief chamber 131 causes the spring seat 121 to move from the main oil circuit 3 towards the electro-proportional valve 2 within the adjustment space 13.

[0078] The diameter of the spring seat 121 is larger than the diameter of the connecting rod 122, so that the force-bearing area of ​​the adjusting member 12 near the main oil passage 3 is larger than the force-bearing area of ​​the adjusting member 12 near the oil inlet 14.

[0079] In one example, the connecting rod 122 has an oil passage 123 extending along the axis of the connecting rod 122, and the oil pressure port 115 and the pressure relief chamber 131 are connected through the oil passage 123.

[0080] like Figures 1 to 7 As shown, the connecting rod 122 has an oil passage 123. The oil passage 123 extends along the axis of the connecting rod 122. When the electro-proportional valve 2 is in the second state, the oil passage 123 is connected to the oil inlet 14 through the oil pressure port 115. When the electro-proportional valve 2 is in the third state, the oil passage 123 is connected to the oil drain port 15 through the oil pressure port 115.

[0081] According to another embodiment of this application, a mechanical device is provided that applies the pressure-reducing electro-proportional relief valve as described above. The mechanical device includes the luffing cylinder, and the pressure-reducing electro-proportional relief valve is connected to the main oil circuit 3 of the luffing cylinder.

[0082] In the embodiment of the present application, the pressure reducing electric proportional overflow valve is suitable for mechanical equipment, for example, the pressure reducing electric proportional overflow valve can be used for boom luffing control of a crane, the pressure reducing electric proportional overflow valve is communicated with the main oil way 3 of the luffing cylinder, the oil pressure of the luffing cylinder is adjusted through the pressure reducing electric proportional overflow valve, the micro-motion performance of the luffing cylinder is improved, the luffing speed of the boom is uniform, and the luffing stability of the boom of the crane is improved.

[0083] According to another embodiment of the present application, a luffing control method is provided, which is applied to the pressure reducing electric proportional overflow valve as described above, the pressure reducing electric proportional valve switches among the first state, the second state and the third state according to the oil pressure of the main oil way 3; the luffing cylinder is signal connected with the electric proportional valve 2, when the oil pressure of the main oil way 3 is within a set threshold, the electric proportional valve 2 is in the first state, the adjusting piece 12 is located at the side of the adjusting space 13 close to the main oil way 3, the oil inlet 14 is communicated with the oil outlet 15, and the pressure relief cavity 131 is disconnected with the oil inlet 14; when the oil pressure of the main oil way 3 is higher than the set threshold, the electric proportional valve 2 switches to the second state, the oil inlet 14 is disconnected with the oil outlet 15, the oil inlet 14 is communicated with the pressure relief cavity 131, the oil liquid enters the pressure relief cavity 131 through the oil inlet 14, based on the increase of the liquid pressure in the pressure relief cavity 131, the adjusting piece 12 moves in the adjusting space 13 from the main oil way 3 to the electric proportional valve 2, and the elastic piece 17 is gradually compressed, and the space of the main oil way 3 increases and the liquid pressure gradually decreases; in the process of the oil pressure of the main oil way 3 decreasing, the electric proportional valve 2 switches to the third state, the oil inlet 14 is disconnected with the oil outlet 15 and the pressure relief cavity 131 respectively, and the pressure relief cavity 131 is communicated with the oil outlet 15, the oil liquid in the pressure relief cavity 131 flows to the oil tank through the oil outlet 15, the liquid pressure in the pressure relief cavity 131 gradually decreases, and the adjusting piece 12 is pushed to move in the adjusting space 13 from the electric proportional valve 2 to the main oil way 3 by the deformation force of the elastic piece 17; when the oil pressure of the main oil way 3 decreases to the range of the set threshold, the adjusting piece 12 is located at the side of the adjusting space 13 close to the main oil way 3, the electric proportional valve 2 switches to the first state, and the electric proportional valve 2 is powered off.

[0084] As shown in Figures 1 to 7 The connecting assembly 11 includes a screw 111 and a screw sleeve 113, the screw 111 and the screw sleeve 113 are threadedly connected, and the two are connected in the screw sleeve 113 to form the adjusting space 13.

[0085] The adjusting member 12 is arranged in the adjusting space 13, and the spring seat 121 of the adjusting member 12 divides the adjusting space 13 into an adjusting cavity and a pressure relief cavity 131, the spring and the connecting rod 122 of the adjusting member 12 are arranged in the adjusting cavity, the spring is sleeved on the connecting rod 122, and the opposite ends of the spring are respectively in abutment with the opposite side walls of the spring seat 121, the end of the connecting rod 122 opposite to the spring seat 121 is embedded in the screw plug 111 and can move along the axis extension direction of the screw plug 111. The connecting rod 122 has a cavity 116 therein, and the oil inlet 14 on the screw plug 111 is communicated with the pressure relief cavity 131 through the cavity 116.

[0086] After the adjusting member 12 is assembled with the connecting assembly 11, the screw plug 111 of the connecting assembly 11 is connected with the electric proportional valve 2, and the oil inlet 14 of the screw plug 111 is communicated with the oil outlet 15 through the on-off interface on the electric proportional valve 2. The electric proportional valve 2 is connected with the connecting assembly 11, and the pressure relief electric proportional overflow valve is assembled.

[0087] When the oil pressure of the main oil circuit 3 is in the set threshold range, the electric proportional valve 2 is in the first state, in the first state, the electric proportional valve 2 is not powered, the adjusting member 12 is located at the end of the adjusting space 13 close to the main oil circuit 3, the oil inlet 14 is communicated with the oil outlet 15, and the pressure relief cavity 131 is not communicated with the oil inlet 14 and the oil outlet 15.

[0088] When the oil pressure of the main oil circuit 3 is higher than the set threshold, the electric proportional valve 2 is in the second state, in the second state, the electric proportional valve 2 is powered, the oil inlet 14 is disconnected with the oil outlet 15, the oil inlet 14 is communicated with the pressure relief cavity 131, the oil enters the pressure relief cavity 131 through the oil inlet 14, and the oil entering the pressure relief cavity 131 pushes the adjusting member 12 to move from the main oil circuit 3 to the electric proportional valve 2, so that the space of the main oil circuit 3 is increased, the oil pressure of the main oil circuit 3 is regulated, and the oil pressure of the main oil circuit 3 is reduced.

[0089] In the process that the oil pressure of the main oil circuit 3 is reduced and gradually restored to the set value range, the electric proportional valve 2 is in the third state, in the third state, the electric proportional valve 2 is powered, the oil inlet 14 is disconnected with the oil outlet 15 and the pressure relief cavity 131, and the oil outlet 15 and the pressure relief cavity 131 are communicated, the oil in the pressure relief cavity 131 flows to the oil tank through the oil outlet 14, in the process, the adjusting member 12 is moved from the electric proportional valve 2 to the main oil circuit 3 by the tension of the elastic member 17, and then the adjusting member 12 is pushed to move to the side of the adjusting space 13 close to the main oil circuit 3.

[0090] When the oil pressure of the main oil circuit 3 is restored to the set threshold, the adjusting member 12 is located at the end of the adjusting space 13 close to the main oil circuit 3, the electric proportional valve 2 is switched to the first state, and the electric proportional valve 2 is powered off.

[0091] In order to improve the falling amplitude stability of a mechanical device (for example, a crane jib), the pressure reducing electric proportional overflow valve is connected with a luffing cylinder of the crane, so that the main oil way 3 oil pressure of the luffing cylinder is adjusted through the pressure reducing electric proportional overflow valve, the micro-motion performance of the luffing cylinder is effectively improved, and the falling amplitude stability of the crane jib is improved.

[0092] Of course, the pressure reducing electric proportional overflow valve in the embodiment of the present application is not limited to the above application scenarios, and those skilled in the art can set it according to actual needs. For example, it can also be applied to important industrial fields such as aviation, aerospace, weapon equipment, steel, power station, etc.

[0093] Although some specific embodiments of the present application have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the present application. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A pressure-reducing electro-proportional relief valve, applied to a variable amplitude cylinder, characterized in that, include: Pressure reducing valve (1), the pressure reducing valve (1) is connected to the main oil circuit (3) of the variable amplitude cylinder, the pressure reducing valve (1) includes a connecting assembly (11) and an adjusting member (12), the connecting assembly (11) has an adjusting space (13), the adjusting member (12) is movably disposed in the adjusting space (13), the adjusting space (13) is provided with an elastic member (17), the elastic member (17) is located between the adjusting member (12) and the inner wall of the adjusting space (13), and the elastic member (17) can undergo elastic deformation along the axial direction of the adjusting space (13), and a pressure relief chamber (131) is formed in the adjusting space (13) and between the adjusting member (12) and the main oil circuit (3), the connecting assembly (11) has an oil inlet (14) and an oil outlet (15), and the end of the connecting assembly (11) away from the oil inlet (14) is connected to the main oil circuit (3); An electro-proportional valve (2) is provided on opposite sides of the connecting assembly (11) along with the main oil circuit (3). The electro-proportional valve (2) has a first state, a second state, and a third state. When the oil pressure in the main oil circuit (3) is within a set threshold, the electro-proportional valve (2) is in a first state, the oil inlet (14) is connected to the oil outlet (15), and the pressure relief chamber (131) is disconnected from the oil inlet (14). When the oil pressure in the main oil circuit (3) is higher than the set threshold, the electro-proportional valve (2) switches to a second state, the oil inlet (14) is disconnected from the oil outlet (15), and the oil inlet (14) is connected to the pressure relief chamber (131). Based on the increase in liquid pressure in the pressure relief chamber (131), the regulating element ( 12) Moving from the main oil circuit (3) toward the electro-proportional valve (2), during the process of the oil pressure dropping in the main oil circuit (3), the electro-proportional valve (2) switches to the third state, the oil inlet (14) is disconnected from the oil drain (15) and the pressure relief chamber (131) respectively, and the pressure relief chamber (131) is connected to the oil drain (15). Based on the decrease in liquid pressure in the pressure relief chamber (131) and the deformation force of the elastic element (17), the adjusting element (12) moves from the electro-proportional valve (2) toward the main oil circuit (3).

2. The pressure-reducing proportional relief valve according to claim 1, characterized in that, The connection component (11) includes: A screw plug (111) is provided with a connecting groove (112). The oil inlet (14) and the oil outlet (15) are both connected to the connecting groove (112). The electro-proportional valve (2) is embedded in the connecting groove (112), and the oil inlet (14) and the oil outlet (15) are connected through the electro-proportional valve (2). A screw plug sleeve (113) is disposed on the side of the screw plug (111) away from the electro-proportional valve (2). The screw plug sleeve (113) has the adjustment space (13). A vent (16) is provided on the screw plug sleeve (113), and the vent (16) is connected to the adjustment space (13).

3. The pressure-reducing proportional relief valve according to claim 2, characterized in that, The screw plug (111) has a protrusion (114) on the side opposite to the electro-proportional valve (2), the protrusion (114) is embedded in the adjustment space (13), and a first sealing element is provided between the outer wall of the protrusion (114) and the inner wall of the screw plug sleeve (113).

4. The pressure-reducing proportional relief valve according to claim 2, characterized in that, The screw plug sleeve (113) has a first end and a second end, the first end and the second end are respectively located on opposite sides of the adjustment space (13), the inner diameter of the first end is adapted to the inner diameter of the adjustment space (13), the inner diameter of the second end is smaller than the inner diameter of the first end, the first end is connected to the screw plug (111), and the second end is connected to the main oil passage (3).

5. The pressure-reducing proportional relief valve according to claim 4, characterized in that, The adjusting component (12) includes a spring seat (121), which is disposed in the adjusting space (13). One end of the spring seat (121) has a connecting rod (122), which is movably disposed in the adjusting space (13). The elastic element (17) is sleeved on the connecting rod (122), and the opposite ends of the elastic element (17) abut against the screw plug (111) and the side wall of the spring seat (121), respectively.

6. The pressure-reducing proportional relief valve according to claim 5, characterized in that, The side of the spring seat (121) opposite to the connecting rod (122) has an insert (124), the diameter of which is adapted to the inner diameter of the second end. The insert (124) is embedded in the cavity (116) of the second end. A second sealing element is provided between the outer wall of the insert (124) and the inner wall of the cavity (116). A third sealing element is provided between the outer wall of the spring seat (121) and the inner wall of the adjustment space (13). The spring seat (121), the third sealing element, the screw plug (113) and the second sealing element together form the pressure relief cavity (131).

7. The pressure-reducing proportional relief valve according to claim 5, characterized in that, The plug (111) has an oil pressure port (115), and the oil inlet (14) and the pressure relief chamber (131) are connected through the oil pressure port (115).

8. The pressure-reducing proportional relief valve according to claim 7, characterized in that, The connecting rod (122) has an oil passage (123) which extends along the axis of the connecting rod (122). The oil pressure port (115) and the pressure relief chamber (131) are connected through the oil passage (123).

9. A mechanical device, characterized in that, The pressure-reducing electro-proportional relief valve as described in any one of claims 1-8 is used, including the luffing cylinder, wherein the pressure-reducing electro-proportional relief valve is connected to the main oil circuit (3) of the luffing cylinder.

10. A method for controlling amplitude drop, characterized in that, Applied to the pressure-reducing electro-proportional relief valve as described in any one of claims 1-8, the electro-proportional valve switches between the first state, the second state and the third state according to the oil pressure of the main oil circuit (3); The variable amplitude cylinder is connected to the electro-proportional valve (2) by signal. When the oil pressure of the main oil circuit (3) is within the set threshold, the electro-proportional valve (2) is in the first state. The regulating element (12) is located on the side of the regulating space (13) close to the main oil circuit (3). The oil inlet (14) is connected to the oil outlet (15). When the oil pressure in the main oil circuit (3) is higher than the set threshold, the electro-proportional valve (2) switches to the second state, the oil inlet (14) is disconnected from the oil outlet (15), and the oil inlet (14) is connected to the pressure relief chamber (131). The oil enters the pressure relief chamber (131) through the oil inlet (14). Based on the increase in the liquid pressure in the pressure relief chamber (131), the regulating member (12) moves from the main oil circuit (3) to the electro-proportional valve (2) in the regulating space (13), and the elastic member (17) is gradually compressed. The space of the main oil circuit (3) increases and the liquid pressure gradually decreases. During the process of the oil pressure in the main oil circuit (3) decreasing, the electro-proportional valve (2) switches to the third state, and the oil inlet (14) is connected to the pressure relief chamber (131). The oil is disconnected from the drain port (15) and the pressure relief chamber (131) respectively, and the pressure relief chamber (131) is connected to the drain port (15). The oil in the pressure relief chamber (131) flows to the oil tank through the drain port (15). The liquid pressure in the pressure relief chamber (131) gradually decreases, and the deformation force of the elastic element (17) pushes the adjusting element (12) to move towards the main oil circuit (3) in the adjusting space (13) by the electro-proportional valve (2). When the oil pressure of the main oil circuit (3) drops to the range of the set threshold, the adjusting element (12) is located on the side of the adjusting space (13) closer to the main oil circuit (3), the electro-proportional valve (2) switches to the first state, and the electro-proportional valve (2) is de-energized.

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