Pressure reduction electric proportional overflow valve, mechanical equipment and falling amplitude control method

Abstract

The invention discloses a pressure reduction electric proportional overflow valve, mechanical equipment and a falling amplitude control method, and relates to the technical field of electric proportional overflow valves. The pressure reducing valve is connected with a main oil way of the variable-amplitude oil cylinder and comprises a connecting assembly and an adjusting part, an adjusting space is formed in the connecting assembly, the adjusting part is movably arranged in the adjusting space, an elastic part is arranged in the adjusting space, and a pressure relief cavity is formed between the adjusting part and the main oil way; the electric proportional valve and the main oil way are arranged on the two opposite sides of the pressure reducing valve, when the oil pressure of the main oil way is within a set threshold value, the electric proportional valve is in a first state, and the oil inlet is communicated with the oil drainage port, and when the oil pressure of the main oil way is higher than the set threshold value, the electric proportional valve is switched to a second state, the oil inlet is disconnected with the oil drainage port, and the oil inlet is communicated with the pressure relief cavity; and in the oil pressure lowering process of the main oil way, the electric proportional valve is switched to the third state, the oil inlet is disconnected with the oil drainage port and the pressure relief cavity, and the pressure relief cavity is communicated with the oil drainage port.

Description

Technical Field

[0001] The present application relates to the technical field of electric proportional relief valves, and more specifically, to a pressure reducing electric proportional relief valve, mechanical equipment and a drop range control method. Background Art

[0002] Engineering machinery uses a hydraulic pilot handle to control the boom lowering speed of the crane, which is controlled by the pilot oil provided by the pilot handle. The boom lowering speed is directly reflected by the movement speed of the luffing cylinder. The boom is supported by the luffing cylinder, and the weight of the boom acts completely on the luffing cylinder. The boom is generally lowered by its own weight. In actual operation, the operator controls the pilot handle to control the boom lowering speed. The adjustment of the lowering speed is a great test of the operator's operating skills. Improper operation can easily lead to the problem that the boom cannot be lowered or the lowering speed is too fast.

[0003] Therefore, it is necessary to provide a new technical solution to improve the oil pressure stability of the variable amplitude cylinder. Summary of the invention

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

[0005] According to a first aspect of the present application, a pressure-reducing electric proportional relief valve is provided, which is applied to a variable-length oil cylinder; the pressure-reducing electric proportional relief valve comprises a pressure-reducing valve and an electric proportional valve; the pressure-reducing valve is connected to the main oil circuit of the variable-length oil cylinder, the pressure-reducing valve comprises a connecting assembly and an adjusting member, the connecting assembly has an adjusting space, 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 the inner wall of the adjusting space, and the elastic member can be elastically deformed along the axial direction of the adjusting space, a pressure relief chamber is formed in the adjusting space and between the adjusting member and the main oil circuit, the connecting assembly has an oil inlet and an oil drain port, an end of the connecting assembly facing away from the oil inlet is connected to the main oil circuit; the electric proportional valve and the main oil circuit are arranged on two opposite sides of the connecting assembly, the electric proportional valve has a first a state, a second state and a third state, wherein, when the oil pressure in the main oil circuit is within a set threshold, the electric proportional valve is in the first state, the oil inlet is connected to the oil drain port, and the pressure relief chamber is disconnected from the oil inlet; when the oil pressure in the main oil circuit is higher than the set threshold, the electric proportional valve switches to the second state, the oil inlet is disconnected from the oil drain port, and the oil inlet is connected to the pressure relief chamber; based on the increase of the liquid pressure in the pressure relief chamber, the regulating member moves from the main oil circuit to the direction of the electric proportional valve; during the decrease of the oil pressure in the main oil circuit, the electric proportional valve switches to the third state, the oil inlet is disconnected from the oil drain port and the pressure relief chamber respectively, and the pressure relief chamber is connected to the oil drain port; based on the decrease of the liquid pressure in the pressure relief chamber and the deformation force of the elastic member, the regulating member moves from the electric proportional valve to the direction of the main oil circuit.

[0006] Optionally, the connecting assembly includes a screw plug and a screw plug sleeve; a connecting groove is provided on the screw plug, the oil inlet and the oil drain port are both connected to the connecting groove, the electric proportional valve is embedded in the connecting groove, and the oil inlet and the oil drain port are connected through the electric proportional valve; the screw plug sleeve is arranged on the side of the screw plug away from the electric proportional valve, the screw plug sleeve has the adjustment space, and an air leak port is provided on the screw plug sleeve, and the air leak port is connected to the adjustment space.

[0007] Optionally, a side of the screw plug facing away from the electric proportional valve has a protrusion, the protrusion is embedded in the adjustment space, and a first sealing member is provided between an outer wall of the protrusion 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 on opposite sides of the adjustment space, the inner diameter of the first end is adapted to the inner diameter of the adjustment space, 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, and the second end is connected to the main oil circuit.

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

[0010] Optionally, the spring seat has an embedding portion on the side facing away from the connecting rod, the diameter of the embedding portion is adapted to the inner diameter of the second end, the embedding portion is embedded in the cavity of the second end, a second seal is provided between the outer wall of the embedding portion and the inner wall of the cavity, a third seal is provided between the outer wall of the spring seat and the inner wall of the adjustment space, and the spring seat, the third seal, the plug sleeve and the second seal enclose the pressure relief chamber.

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

[0012] Optionally, an oil channel is provided in the connecting rod, the oil channel is opened along the extending direction of the axis of the connecting rod, and the oil pressure port and the pressure relief chamber are connected through the oil channel.

[0013] According to a second aspect of the present application, a mechanical device is provided, which uses the pressure-reducing electric proportional relief valve as described above, and the mechanical device includes the variable-length oil cylinder, and the pressure-reducing electric proportional relief valve is connected to the main oil circuit of the variable-length oil cylinder.

[0014] According to a third aspect of the present application, a method for controlling the amplitude of a drop is provided, which is applied to the pressure-reducing electric proportional relief valve as described above, wherein the pressure-reducing electric proportional valve switches between the first state, the second state and the third state according to the oil pressure of the main oil circuit; the amplitude-changing oil cylinder is connected to the electric proportional valve signal, and when the oil pressure of the main oil circuit is within a set threshold value, the electric proportional valve is in the first state, the adjusting member is located on a side of the adjusting space close to the main oil circuit, and the oil inlet is connected to the oil drain port; when the oil pressure of the main oil circuit is higher than the set threshold value, the electric proportional valve switches to the second state, the oil inlet is disconnected from the oil drain port, and the oil inlet is connected to the pressure relief chamber, and the oil enters the pressure relief chamber through the oil inlet, and based on the increase of the liquid pressure in the pressure relief chamber, the adjusting member is in the second state. The regulating space moves from the main oil circuit to the electric proportional valve, and the elastic member is gradually compressed, the main oil circuit space increases and the liquid pressure gradually decreases; during the process of the main oil circuit oil pressure decreasing, the electric proportional valve switches to the third state, the oil inlet is disconnected from the oil drain port and the pressure relief chamber respectively, and the pressure relief chamber is connected to the oil drain port, the oil in the pressure relief chamber flows to the oil tank through the oil drain port, the liquid pressure in the pressure relief chamber gradually decreases, and the deformation force of the elastic member pushes the regulating member to move from the electric proportional valve to the main oil circuit in the regulating space; when the oil pressure of the main oil circuit drops to within the set threshold range, the regulating member is located on the side of the regulating space close to the main oil circuit, 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 electric proportional relief valve is switched between the first state, the second state and the third state by cooperating with the pressure reducing valve and the electric proportional valve to adjust the oil pressure of the main oil circuit. When the oil pressure of the main oil circuit is within the normal threshold range, the electric proportional valve is in the first state, the regulating member is located on the side of the regulating space close to the main oil circuit, and the oil inlet and the oil drain port are connected, and the oil pressure of the main oil circuit does not need to be adjusted. When the oil pressure of the main oil circuit is higher than the set threshold, the electric proportional valve is in the second state, the electric proportional valve is energized to disconnect the oil inlet and the oil drain port, and the oil inlet and the pressure relief chamber are connected, the oil enters the pressure relief chamber through the oil inlet, and the oil in the pressure relief chamber pushes the regulating member to move from the main oil circuit to the direction of the electric proportional valve, so that the air in the main oil circuit is The time increases and the oil pressure decreases. During the process of the oil pressure in the main oil circuit decreasing, the electric proportional valve is in the third state, the oil inlet is disconnected from the oil drain port and the pressure relief chamber respectively, and the oil drain port is connected to the pressure relief chamber, the oil in the pressure relief chamber flows back to the oil tank through the oil drain port, and the tension of the elastic member pushes the adjusting member to move from the electric proportional valve to the direction of the main oil circuit. When the oil pressure in the main oil circuit recovers to the set threshold range, the electric proportional valve switches to the first state, the pressure relief chamber is disconnected from the oil inlet and the oil drain port respectively, and the oil inlet is connected to the oil drain port. The electric proportional valve switches between the first state, the second state and the third state to adjust the oil pressure of the main oil circuit, effectively enhancing the oil pressure stability of the main oil circuit of the boom cylinder, thereby improving the micro-motion performance of the boom cylinder and the stability of the boom drop of the crane.

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

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

[0018] Figure 1 Schematic diagram of the structure of the pressure reducing electric proportional relief valve in the embodiment of the present application; Figure 2 is a top view of a pressure reducing electric proportional relief valve in an embodiment of the present application; Figure 3 yes Figure 2 Schematic diagram of the cross section of AA; Figure 4 yes Figure 3 An enlarged schematic diagram of the circled part; Figure 5 Schematic diagram of the structure of the screw plug in the embodiment of the present application; Figure 6 It is a schematic diagram of the structure of the screw plugging sleeve in the embodiment of the present application; Figure 7It is a schematic diagram of the structure of the adjusting member in the embodiment of the present application.

[0019] Description of reference numerals: 1- Pressure reducing valve; 11-connection assembly; 111-screw plug; 112-connection groove; 113-screw plug sleeve; 114-protrusion; 115-oil pressure port; 116-cavity; 12-adjusting member; 121-spring seat; 122-connecting rod; 123-oil channel; 124-embedded part; 13-adjusting space; 131-pressure relief chamber; 14-Oil inlet; 15-Oil drain port; 16-vent; 17- elastic member; 2-Electric proportional valve; 3- Main oil circuit. DETAILED DESCRIPTION

[0020] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0021] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present application, its application, or uses.

[0022] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0023] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0024] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0025] According to one embodiment of the present application, a pressure reducing electric proportional relief valve is provided, which is applied to a variable-luff cylinder. The pressure reducing electric proportional relief valve comprises a pressure reducing valve 1 and an electric proportional valve 2; the pressure reducing valve 1 is connected to the main oil circuit 3 of the variable amplitude oil cylinder, the pressure reducing valve 1 comprises a connecting assembly 11 and an adjusting member 12, the connecting assembly 11 has an adjusting space 13, the adjusting member 12 is movably arranged in the adjusting space 13, an elastic member 17 is arranged in 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 be elastically deformed 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 drain port 15, and the end of the connecting assembly 11 away from the oil inlet 14 is connected to the main oil circuit 3; the electric proportional valve 2 and the main oil circuit 3 are arranged on two opposite sides of the connecting assembly 11, and the electric proportional valve 2 has a first state , a second state and a third state, wherein, when the oil pressure in the main oil circuit 3 is within a set threshold, the electric proportional valve 2 is in the first state, the oil inlet 14 is connected to the oil drain port 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 electric proportional valve 2 switches to the second state, the oil inlet 14 is disconnected from the oil drain port 15, and the oil inlet 14 is connected to the pressure relief chamber 131, and the end of the elastic member 17 close to the adjusting member 12 moves from the main oil circuit 3 to the direction of the electric proportional valve 2; during the process of the oil pressure in the main oil circuit 3 decreasing, the electric proportional valve 2 switches to the third state, the oil inlet 14 is disconnected from the oil drain port 15 and the pressure relief chamber 131 respectively, and the pressure relief chamber 131 is connected to the oil drain port 15, and the end of the elastic member 17 close to the adjusting member 12 moves from the electric proportional valve 2 to the direction of the main oil circuit 3.

[0026] like Figures 1 to 7 As shown, the electric proportional valve 2 is connected to the main oil circuit 3 of the boom cylinder through the pressure reducing valve 1. When the oil pressure in the main oil circuit 3 is at the normal threshold, the oil pressure in the main oil circuit 3 does not need to be adjusted, the electric proportional valve 2 is not energized, and the regulating member 12 of the pressure reducing valve 1 is located on the side close to the main oil circuit 3; when the oil pressure in the main oil circuit 3 exceeds the set threshold, the electric proportional valve 2 is energized to drive the regulating member 12 of the pressure reducing valve 1 to move to the side away from the main oil circuit 3, thereby reducing the oil pressure in the main oil circuit 3, achieving a uniform lifting speed of the crane and improving the lifting stability.

[0027] The pressure reducing valve 1 comprises a connecting assembly 11 and an adjusting member 12, wherein an adjusting space 13 in the connecting assembly 11 is cylindrical, wherein one end of the connecting assembly 11 is connected to the electric proportional valve 2, and the other end of the connecting assembly 11 is connected to the main oil circuit 3. The oil inlet 14 and the oil drain 15 on the connecting assembly 11 are both arranged on one side of the connecting assembly 11 close to the electric proportional valve 2, and the oil inlet 14 and the oil drain 15 can be switched between the first state, the second state and the third state by the electric proportional valve 2, so as to be turned on and off by the conduction interface of the electric proportional valve 2.

[0028] The adjusting member 12 is disposed in the adjusting space 13 . The elastic member 17 is a spring. The spring is disposed in the adjusting space 13 and is movable along the axial direction of the adjusting space 13 .

[0029] When the oil pressure in the main oil circuit 3 is within 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 energized, the adjusting member 12 is located at one end of the adjusting space 13 close to the main oil circuit 3, and the oil inlet 14 is connected to the oil drain port 15, and the pressure relief chamber 131 is not connected to the oil inlet 14 and the oil drain port 15.

[0030] When the oil pressure in 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 energized, the oil inlet 14 is disconnected from the oil drain port 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. The oil entering the pressure relief chamber 131 pushes the regulating member 12 to move from the main oil circuit 3 to the direction of the electric proportional valve 2, thereby increasing the space of the main oil circuit 3 and adjusting the oil pressure of the main oil circuit 3.

[0031] During the process that the oil pressure in 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 energized, the oil inlet 14 is disconnected from the oil drain port 15 and the pressure relief chamber 131, and the oil drain port 15 and the pressure relief chamber 131 are connected, and the oil in the pressure relief chamber 131 flows to the oil tank through the oil drain port 14. During this process, the adjusting member 12 is supported by the elastic member 17 and moves from the electric proportional valve 2 to the direction of the main oil circuit 3, so that the adjusting member 12 moves to the side of the adjusting space 13 close to the main oil circuit 3.

[0032] By switching the electric proportional valve 2 among the first state, the second state and the third state, the pressure reducing valve 1 adjusts the oil pressure of the main oil circuit 3, thereby making the drop of the crane uniform and improving the drop stability.

[0033] Of course, the pressure reducing electric proportional relief valve in the embodiment of the present application is not limited to the above-mentioned 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, weapons and equipment, steel, and power stations.

[0034] In the embodiment of the present application, the pressure reducing electric proportional relief valve is switched between the first state, the second state and the third state by cooperating with the pressure reducing valve 1 and the electric proportional valve 2, 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 regulating member 12 is located on the side of the regulating space 13 close to the main oil circuit 3, and the oil inlet 14 is connected to the oil drain port 15, 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 from the oil drain port 15, and the oil inlet 14 is connected to the pressure relief chamber 131, and the oil enters the pressure relief chamber 131 through the oil inlet 14, and the oil in the pressure relief chamber 131 pushes the regulating member 12 to move from the main oil circuit 3 to the direction of the electric proportional valve 2, so that the air in the main oil circuit 3 is The time increases and the oil pressure decreases. During the oil pressure decreases in the main oil circuit 3, the electric proportional valve 2 is in the third state, the oil inlet 14 is disconnected from the oil drain port 15 and the pressure relief chamber 131 respectively, and the oil drain port 15 is connected to the pressure relief chamber 131, and the oil in the pressure relief chamber 131 flows back to the oil tank through the oil drain port 15, and the tension of the elastic member 17 pushes the adjusting member 12 to move from the electric proportional valve 2 to the direction of the main oil circuit 3. When the oil pressure in the main oil circuit 3 recovers to the set threshold range, the electric proportional valve 2 switches to the first state, the pressure relief chamber 131 is disconnected from the oil inlet 14 and the oil drain port 15 respectively, and the oil inlet 14 is connected to the oil drain port 15. The electric proportional valve 2 switches between the first state, the second state and the third state to adjust the oil pressure in the main oil circuit 3, effectively enhancing the oil pressure stability of the main oil circuit 3 of the boom cylinder, thereby improving the micro-motion performance of the boom cylinder and the amplitude stability of the mechanical equipment.

[0035] In one example, the connecting assembly 11 includes a screw plug 111 and a screw plug sleeve 113; a connecting groove 112 is provided on the screw plug 111, the oil inlet 14 and the oil drain port 15 are both connected to the connecting groove 112, the electric proportional valve 2 is embedded in the connecting groove 112, and the oil inlet 14 and the oil drain port 15 are connected through the electric proportional valve 2; the screw plug sleeve 113 is arranged on the side of the screw plug 111 away from the electric proportional valve 2, the screw plug sleeve 113 has the adjustment space 13, and an air leak port 16 is provided on the screw plug sleeve 113, and the air leak port 16 is connected to the adjustment space 13.

[0036] like Figures 1 to 7As shown, the opposite ends of the screw plug 111 are respectively connected to the electric proportional valve 2 and the screw plug sleeve 113, and 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 conduction interface on the electric proportional valve 2 corresponds to the oil inlet 14 and the oil drain port 15 on the screw plug 111. The electric proportional valve 2 is switched between the first state, the second state and the third state, so that the oil inlet 14 and the oil drain port 15 are connected and disconnected.

[0037] like Figures 5 and 6 As shown, the plug sleeve 113 is arranged at the end of the plug 111 away from the electric proportional valve 2, and the adjusting member 12 is arranged in the adjusting space 13 of the plug sleeve 113. The adjusting member 12 can move along the axial direction of the adjusting space 13, and can form a pressure relief chamber 131 at the end of the adjusting space 13 away from the plug 111. When the oil pressure of the main oil circuit 3 is higher than the set threshold, the pressure relief chamber 131 is connected with the oil inlet 14, and the oil in the pressure relief chamber 131 pushes the adjusting member 12 to move from the main oil circuit 3 to the direction of the electric proportional valve 2. The side of the plug sleeve 113 close to the pressure relief chamber 131 is connected with the main oil circuit 3.

[0038] When the oil pressure in 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 energized, the oil inlet 14 is connected with the pressure relief chamber 131, and the oil enters the pressure relief chamber 131 through the oil inlet 14, pushing the adjusting member 12 to move from the main oil circuit 3 to the direction of 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 relief port 15 is connected with the pressure relief chamber 131, the oil inlet 14 and the oil relief port 15 and the pressure relief chamber 131 are all in the disconnected state, the adjusting member 12 moves from the electric proportional valve 2 to the direction of the main oil circuit 3, and the oil in the pressure relief chamber 131 flows back to the oil tank through the air bleed port 16 until the oil pressure in the main oil circuit 3 returns to the set threshold value. The adjusting member 12 is located on the side of the adjusting space 13 close to the main oil circuit 3, effectively adjusting the oil pressure of the main oil circuit 3 to be stable, so that the drop width of the crane is uniform and the drop width stability is improved.

[0039] The vent port 16 is provided on the screw plug sleeve 113, and the vent port 16 is communicated with the regulating space 13. By providing the vent port 16 communicated with the regulating space 13 on the screw plug sleeve 113, when the spring seat 121 moves in the regulating space 13, the gas in the regulating space 13 flows, and the regulating space 13 is prevented from becoming a dead space, which affects the regulating effect of the pressure reducing valve 1. In one example, the side of the screw plug 111 facing away from the electric proportional valve 2 has a protrusion 114 , the protrusion 114 is embedded in the adjustment space 13 , and a first seal is provided between the outer wall of the protrusion 114 and the inner wall of the screw plug sleeve 113 .

[0040] like Figures 1 to 7 As shown, one side of the screw plug 111 has a protrusion 114, the outer diameter of the protrusion 114 is adapted to the inner diameter of the adjustment space 13, the screw plug sleeve 113 is arranged on the protrusion 114, and a retaining ring and a first sealing member are arranged between the protrusion 114 and the screw plug sleeve 113. The retaining ring can effectively improve the connection strength between the screw plug 111 and the screw plug sleeve 113, and the first sealing member can prevent oil leakage during the oil pressure regulation process from causing equipment damage.

[0041] The first sealing member and the retaining ring can be made of materials such as rubber and silicone.

[0042] 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 on opposite sides of the regulating space 13, the inner diameter of the first end is adapted to the inner diameter of the regulating 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 circuit 3.

[0043] like Figures 1 to 7 As shown, the plug sleeve 113 has a first end and a second end. The outer diameter of the first end of the plug sleeve 113 is greater than the outer diameter of the second end of the plug sleeve 113, and the inner diameter of the first end of the plug sleeve 113 is greater than the inner diameter of the second end of the plug sleeve 113. The inner diameter of the adjustment space 13 is greater than the inner diameter of the second end. The inner diameter of the first end is matched with the inner diameter of the adjustment space 13.

[0044] 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 on the two opposite sides of the adjustment space 13 are smaller than the diameter of the spring seat 121, so as to limit the moving space of the spring seat 121 and adjust the oil pressure of the main oil circuit 3.

[0045] The first end of the plug sleeve 113 is connected to the protruding portion 114 of the plug 111, that is, the protruding portion 114 of the plug 111 is embedded in the first end and abuts against the spring. By embedding the protruding portion 114 in the first end, not only can the connection strength between the plug 111 and the plug sleeve 113 be effectively enhanced, but also the spring seat 121 and the connecting rod 122 can be moved in the adjustment space 13 through the spring to adjust the oil pressure of the main oil circuit 3.

[0046] Of course, in the embodiment of the present application, the screw plug 111 and the screw plug sleeve 113 are not limited to the above structure, 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 integrated structure, and the screw plug 111 and the screw plug sleeve 113 form an adjustment space 13 for placing the adjustment member 12 and the elastic member 17.

[0047] In one example, the adjusting member 12 includes a spring seat 121 and the elastic member 17, the spring seat 121 is arranged in the adjusting space 13, one end of the spring seat 121 has a connecting rod 122, the connecting rod 122 is movably arranged in the adjusting space 13, the elastic member 17 is sleeved on the connecting rod 122, and the opposite ends of the elastic member 17 are respectively against the screw plug 111 and the side wall of the spring seat 121.

[0048] like Figures 1 to 7 As shown, the elastic member 17 is a spring. The adjusting member 12 includes a spring seat 121 and a spring, both of which are arranged in the adjusting space 13, the adjusting space 13 is cylindrical, the spring seat 121 is in the shape of a circular plate, and a connecting rod 122 is arranged on one side of the spring seat 121 close to the electric proportional valve 2, and the connecting rod 122 is in the shape of a column.

[0049] One end of the screw plug 111 embedded in the screw plug sleeve 113 has a groove connected to the adjustment space 13, one end of the connecting rod 122 is fixedly connected to the spring seat 121, the other end of the connecting rod 122 is embedded in the groove, and a fourth sealing member is arranged between the outer wall of the connecting rod 122 and the inner wall of the groove. The fourth sealing member can be made of rubber, silicone or other materials.

[0050] The spring sleeve is arranged on the connecting rod 122, and one end of the spring abuts against the end of the screw plug 111, and the other end of the spring abuts 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 in the adjustment space 13.

[0051] When the oil pressure in 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, the oil inlet 14 is connected to the pressure relief chamber 131, and the oil enters the pressure relief chamber 131 through the oil inlet 14, pushing the regulating member 12 to move from the main oil circuit 3 to the direction of the electric proportional valve 2, thereby reducing the pressure in the main oil circuit 3.

[0052] When the oil pressure in the main oil circuit 3 gradually decreases, the electric proportional valve 2 is in the third state, the oil inlet 14 is disconnected from the pressure relief chamber 131 and the oil drain port 15, and the pressure relief chamber 131 and the oil drain port 15 are connected, the oil in the pressure relief chamber 131 flows back to the oil tank through the oil drain port 15, and the spring seat 121 is moved from the electric proportional valve 2 to the main oil circuit 3 by the spring until the regulating member 12 moves to the side of the regulating space 13 close to the main oil circuit 3, and the oil pressure of the main oil circuit 3 is restored to the set threshold range, and the electric proportional valve 2 is switched to the first state, the electric proportional valve 2 is not energized, and the electric proportional valve 2 is switched between the first state, the second state and the third state bracket to adjust the oil pressure of the main oil circuit 3 to be stable, so that the drop width of the crane is uniform and the drop width stability is improved.

[0053] In the embodiment of the present application, an oil channel 123 may be opened on the connecting rod 122 so that the oil inlet 14 is in communication with the pressure relief chamber 131 .

[0054] Of course, in the embodiment of the present application, the oil inlet 14 and the pressure relief chamber 131 are not limited to the above structure, and those skilled in the art can set it according to actual needs. For example, an oil channel 123 is opened on the screw plug 111 and the screw plug sleeve 113, so that the oil inlet 14 and the pressure relief chamber 131 are connected through the oil channel 123.

[0055] like Figure 3 As shown, the diameter of the spring seat 121 is larger than the diameter of the connecting rod 122, so that the force-bearing areas of the two opposite sides of the adjusting member 12 are different, that is, the force-bearing area of ​​the side of the adjusting member 12 close to the oil inlet 14 is smaller than the force-bearing area of ​​the side of the adjusting member 12 close to the pressure relief chamber 131. With this design, when the oil enters the pressure relief chamber 131 through the oil channel 123, the force on the adjusting member 12 from the electric proportional valve 2 to the main oil circuit 3 is reduced, and because the force-bearing area of ​​the spring seat 121 is larger than the force-bearing area of ​​the connecting rod 122, it is beneficial to push the spring seat 121 from the main oil circuit 3 to the electric proportional valve 2 through the oil pressure in the pressure relief chamber 131.

[0056] In one example, the spring seat 121 has an embedding portion 124 on one side facing away from the connecting rod 122, and the diameter of the embedding portion 124 is adapted to the inner diameter of the second end. The embedding portion 124 is embedded in the cavity 116 of the second end, and a second seal is provided between the outer wall of the embedding portion 124 and the inner wall of the cavity 116. A third seal 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 seal, the plug sleeve 113 and the second seal enclose the pressure relief chamber 131.

[0057] like Figures 1 to 7 As shown, the spring seat 121 is in the shape of a circular plate, is arranged in the adjustment space 13, and can move along the axial direction of the adjustment space 13. An embedding portion 124 is arranged on the side of the spring seat 121 away from the connecting rod 122, the diameter of the embedding portion 124 is adapted to the inner diameter of the second end, and a second seal is arranged between the outer wall of the embedding portion 124 and the inner wall of the second end. A fourth seal is arranged between the outer wall of the spring seat 121 and the inner wall of the adjustment space 13, and the second seal and the fourth seal can be made of rubber, silicone and other materials.

[0058] By arranging a fourth seal between the outer wall of the spring seat 121 and the inner wall of the adjustment space 13, and arranging a second seal between the outer wall of the embedded portion 124 and the inner wall of the second end, the spring seat 121, the plug sleeve 113 and the embedded portion 124 enclose a pressure relief chamber 131. The pressure relief chamber 131 is communicated with the oil channel 123, so that the oil flows into the pressure relief chamber 131 through the oil inlet 14 and the oil channel 123, so as to push the spring seat 121 to move from the main oil circuit 3 to the direction of the electric proportional valve 2, and effectively reduce the risk of oil leakage.

[0059] In one example, the screw plug 111 has an oil pressure port 115 , and the oil inlet 14 and the pressure relief chamber 131 are communicated with each other through the oil pressure port 115 .

[0060] like Figures 1 to 7 As shown, the oil pressure port 115 is provided on the screw plug 111 and communicates with the oil inlet 14 and the oil channel 123. When the oil enters through the oil inlet 14, the oil enters the oil pressure port 115 and the oil channel 123 to generate corresponding oil pressure, and enters the pressure relief chamber 131 through the oil channel 123 on the connecting rod 122. The liquid pressure in the pressure relief chamber 131 increases, so that the spring seat 121 moves from the main oil circuit 3 to the direction of the electric proportional valve 2 in the adjustment space 13.

[0061] The diameter of the spring seat 121 is larger than the diameter of the connecting rod 122 , so that the stress-bearing area of ​​the adjusting member 12 close to the main oil circuit 3 is larger than the stress-bearing area of ​​the adjusting member 12 close to the oil inlet 14 .

[0062] In one example, the connecting rod 122 has an oil passage 123 therein, the oil passage 123 is opened along the axis extension direction of the connecting rod 122 , and the oil pressure port 115 and the pressure relief chamber 131 are connected through the oil passage 123 .

[0063] like Figures 1 to 7 As shown, there is an oil passage 123 in the connecting rod 122. The oil passage 123 is opened along the axis extension direction of the connecting rod 122, and when the electric 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, and when the electric 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.

[0064] According to another embodiment of the present application, a mechanical device is provided, which uses the pressure-reducing electric proportional relief valve as described above, and includes the variable-length oil cylinder, and the pressure-reducing electric proportional relief valve is connected to the main oil circuit 3 of the variable-length oil cylinder.

[0065] In an embodiment of the present application, the pressure-reducing electric proportional relief valve is suitable for mechanical equipment. For example, the pressure-reducing electric proportional relief valve can be used for controlling the arm drop of a crane. The pressure-reducing electric proportional relief valve is connected to the main oil circuit 3 of the boom cylinder. The oil pressure of the boom cylinder is adjusted by the pressure-reducing electric proportional relief valve to improve the micro-motion performance of the boom cylinder, so that the arm drop speed is uniform, thereby improving the arm drop stability of the crane.

[0066] According to another embodiment of the present application, a method for controlling the amplitude of a drop is provided, and the method for controlling the amplitude of a drop is applied to the pressure-reducing electric proportional relief valve as described above, wherein the pressure-reducing electric 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 amplitude-changing oil cylinder is connected to the electric proportional valve 2 by signal, and when the oil pressure of the main oil circuit 3 is within a set threshold, the electric proportional valve 2 is in the first state, the regulating member 12 is located on a side of the regulating space 13 close to the main oil circuit 3, the oil inlet 14 is connected to the oil drain port 15, and the pressure relief chamber 131 is disconnected from the oil inlet 14; when the oil pressure of the main oil circuit 3 is higher than the set threshold, the electric proportional valve 2 switches to the second state, the oil inlet 14 is disconnected from the oil drain port 15, and the oil inlet 14 is connected to the pressure relief chamber 131, and 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 is connected to the second state. The node 12 moves from the main oil circuit 3 to the electric 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 decreasing in the main oil circuit 3, the electric proportional valve 2 switches to the third state, the oil inlet 14 is disconnected from the oil drain port 15 and the pressure relief chamber 131 respectively, and the pressure relief chamber 131 is connected to the oil drain port 15, the oil in the pressure relief chamber 131 flows to the oil tank through the oil drain port 15, the liquid pressure in the pressure relief chamber 15 gradually decreases, and the deformation force of the elastic member 17 pushes the regulating member 12 to move from the electric proportional valve 2 to the main oil circuit 3 in the regulating space 13; when the oil pressure in the main oil circuit 3 drops to within the range of the set threshold, the regulating member 12 is located on the side of the regulating space 13 close to the main oil circuit 3, the electric proportional valve 2 switches to the first state, and the electric proportional valve 2 is powered off.

[0067] like Figures 1 to 7 As shown, the connection assembly 11 includes a screw plug 111 and a screw plug sleeve 113 . The screw plug 111 and the screw plug sleeve 113 are threadedly connected, and the two are connected in the screw plug sleeve 113 to form an adjustment space 13 .

[0068] 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 chamber and a pressure relief chamber 131. The spring and the connecting rod 122 of the adjusting member 12 are arranged in the adjusting chamber, and the spring is sleeved on the connecting rod 122, and the opposite ends of the spring are respectively against the opposite side walls of the screw plug 111 and the spring seat 121, and 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, and the oil inlet 14 on the screw plug 111 is connected with the pressure relief chamber 131 through the cavity 116.

[0069] After the adjustment member 12 is assembled with the connecting assembly 11, the screw plug 111 of the connecting assembly 11 is connected to the electric proportional valve 2, and the conducting interface on the electric proportional valve 2 can make the oil inlet 14 of the screw plug 111 conduct with the oil drain port 15. The electric proportional valve 2 is connected with the connecting assembly 11, and the pressure reducing electric proportional relief valve is assembled.

[0070] When the oil pressure in the main oil circuit 3 is within the set threshold range, the electric proportional valve 2 is in the first state. When the electric proportional valve 2 is in the first state, the electric proportional valve 2 is not energized, the adjusting member 12 is located at one end of the adjusting space 13 close to the main oil circuit 3, and the oil inlet 14 is connected to the oil drain port 15, and the pressure relief chamber 131 is not connected to the oil inlet 14 and the oil drain port 15.

[0071] When the oil pressure in the main oil circuit 3 is higher than the set threshold, the electric proportional valve 2 is in the second state. When the electric proportional valve 2 is in the second state, the electric proportional valve 2 is energized, the oil inlet 14 is disconnected from the oil drain port 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. The oil entering the pressure relief chamber 131 pushes the regulating member 12 to move from the main oil circuit 3 to the direction of the electric proportional valve 2, thereby increasing the space of the main oil circuit 3, adjusting the oil pressure of the main oil circuit 3, and reducing the oil pressure of the main oil circuit 3.

[0072] During the process that the oil pressure in the main oil circuit 3 decreases and gradually recovers to the set value range, the electric proportional valve 2 is in the third state. When the electric proportional valve 2 is in the third state, the electric proportional valve 2 is energized, the oil inlet 14 is disconnected from the oil drain port 15 and the pressure relief chamber 131, and the oil drain port 15 and the pressure relief chamber 131 are connected, and the oil flow in the pressure relief chamber 131 flows to the oil tank through the oil drain port 14. In this process, the tension of the elastic member 17 causes the adjusting member 12 to move from the electric proportional valve 2 to the direction of the main oil circuit 3, thereby pushing the adjusting member 12 to move to the side of the adjusting space 13 close to the main oil circuit 3.

[0073] When the oil pressure in the main oil circuit 3 recovers to the set threshold, the regulating member 12 is located at one end of the regulating space 13 close to the main oil circuit 3, the electric proportional valve 2 switches to the first state, and the electric proportional valve 2 is de-energized.

[0074] In order to improve the stability of the falling range of mechanical equipment (for example, crane boom), the pressure-reducing electric proportional relief valve is connected to the boom cylinder of the crane, so that the oil pressure in the main oil circuit 3 of the boom cylinder can be adjusted through the pressure-reducing electric proportional relief valve, thereby effectively improving the micro-motion performance of the boom cylinder and improving the stability of the falling range of the crane boom.

[0075] Of course, the pressure reducing electric proportional relief 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, weapons and equipment, steel, and power stations.

[0076] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may 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 electric proportional relief valve, applied to a variable-luffing cylinder, characterized in that: include: A pressure reducing valve (1), the pressure reducing valve (1) being connected to a main oil circuit (3) of the variable-length oil cylinder, the pressure reducing valve (1) comprising a connecting assembly (11) and an adjusting member (12), the connecting assembly (11) having an adjusting space (13), the adjusting member (12) being movably arranged in the adjusting space (13), an elastic member (17) being arranged in the adjusting space (13), the elastic member (17) being located between the adjusting member (12) and an inner wall of the adjusting space (13), and the elastic member (17) being capable of elastic deformation along an axial direction of the adjusting space (13), forming a pressure relief chamber (131) in the adjusting space (13) and between the adjusting member (12) and the main oil circuit (3), the connecting assembly (11) having an oil inlet (14) and an oil drain port (15), and an end of the connecting assembly (11) facing away from the oil inlet (14) being in communication with the main oil circuit (3); An electric proportional valve (2), wherein the electric proportional valve (2) and the main oil circuit (3) are arranged on two opposite sides of the connecting component (11), and the electric proportional valve (2) has a first state, a second state and a third state. Wherein, when the oil pressure of the main oil circuit (3) is within a set threshold, the electric proportional valve (2) is in a first state, the oil inlet (14) is connected to the oil drain port (15), and the pressure relief chamber (131) is disconnected from the oil inlet (14); when the oil pressure of the main oil circuit (3) is higher than the set threshold, the electric proportional valve (2) switches to a second state, the oil inlet (14) is disconnected from the oil drain port (15), and the oil inlet (14) is connected to the pressure relief chamber (131); based on the increase in the liquid pressure in the pressure relief chamber (131), the regulating member ( The adjusting member (12) moves from the main oil circuit (3) toward the electric proportional valve (2). When the oil pressure in the main oil circuit (3) decreases, the electric proportional valve (2) switches to the third state. The oil inlet (14) is disconnected from the oil drain port (15) and the pressure relief chamber (131) respectively, and the pressure relief chamber (131) is connected to the oil drain port (15). Based on the decrease in the liquid pressure in the pressure relief chamber (131) and the deformation force of the elastic member (17), the adjusting member (12) moves from the electric proportional valve (2) toward the main oil circuit (3).

2. The pressure reducing electric proportional relief valve according to claim 1, characterized in that: The connection component (11) comprises: a screw plug (111), wherein a connecting groove (112) is formed on the screw plug (111), the oil inlet (14) and the oil drain port (15) are both 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 drain port (15) are in communication with each other through the electric proportional valve (2); A screw plug sleeve (113), the screw plug sleeve (113) being arranged on a side of the screw plug (111) facing away from the electric proportional valve (2), the screw plug sleeve (113) having the adjustment space (13), and an air vent (16) being provided on the screw plug sleeve (113), the air vent (16) being in communication with the adjustment space (13).

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

4. The pressure reducing electric 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 regulating space (13), the inner diameter of the first end is matched to the inner diameter of the regulating 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 circuit (3).

5. The pressure reducing electric proportional relief valve according to claim 4, characterized in that: The adjusting member (12) comprises a spring seat (121), the spring seat (121) being arranged in the adjusting space (13), one end of the spring seat (121) having a connecting rod (122), the connecting rod (122) being movably arranged in the adjusting space (13), the elastic member (17) being sleeved on the connecting rod (122), and opposite ends of the elastic member (17) respectively abutting against the screw plug (111) and the side wall of the spring seat (121).

6. The pressure reducing electric proportional relief valve according to claim 5, characterized in that: The spring seat (121) has an embedding portion (124) on a side facing away from the connecting rod (122); the diameter of the embedding portion (124) is matched to the inner diameter of the second end; the embedding portion (124) is embedded in the cavity (116) of the second end; a second sealing member is provided between an outer wall of the embedding portion (124) and an inner wall of the cavity (116); a third sealing member is provided between an outer wall of the spring seat (121) and an inner wall of the regulating space (13); the spring seat (121), the third sealing member, the plug sleeve (113) and the second sealing member enclose the pressure relief chamber (131).

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

8. The pressure reducing electric proportional relief valve according to claim 7, characterized in that: An oil channel (123) is provided in the connecting rod (122), the oil channel (123) being opened along the extending direction of the axis of the connecting rod (122), and the oil pressure port (115) and the pressure relief chamber (131) are connected via the oil channel (123).

9. A mechanical device, characterized in that: The pressure reducing electric proportional relief valve according to any one of claims 1 to 8 comprises the luffing cylinder, and the pressure reducing electric proportional relief valve is connected to the main oil circuit (3) of the luffing cylinder.

10. A method for controlling the width of a drop, characterized in that: Applicable to the pressure reducing electric proportional relief valve as claimed in any one of claims 1 to 8, wherein the pressure reducing electric 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-luff cylinder is signal-connected to the electric proportional valve (2); when the oil pressure of the main oil circuit (3) is within a set threshold, the electric proportional valve (2) is in a first state, the regulating member (12) is located on a side of the regulating space (13) close to the main oil circuit (3), and the oil inlet (14) is connected to the oil drain port (15); When the oil pressure in the main oil circuit (3) is higher than a set threshold, the electric proportional valve (2) switches to the second state, the oil inlet (14) is disconnected from the oil drain port (15), and the oil inlet (14) is connected to the pressure relief chamber (131), and 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 electric proportional valve (2) in the regulating space (13), and the elastic member (17) is gradually compressed, so that the space in the main oil circuit (3) increases and the liquid pressure gradually decreases. During the process of decreasing the oil pressure in the main oil circuit (3), the electric proportional valve (2) switches to the third state, the oil inlet (14) is disconnected from the oil drain port (15), and the oil drain port (15) is connected to the pressure relief chamber (131). ) are disconnected from the oil drain port (15) and the pressure relief chamber (131) respectively, and the pressure relief chamber (131) is connected to the oil drain port (15), the oil in the pressure relief chamber (131) flows to the oil tank through the oil drain port (15), the liquid pressure in the pressure relief chamber (15) gradually decreases, and the deformation force of the elastic member (17) pushes the regulating member (12) to move from the electric proportional valve (2) to the main oil circuit (3) in the regulating space (13); when the oil pressure in the main oil circuit (3) drops to within a set threshold range, the regulating member (12) is located on a side of the regulating space (13) close to the main oil circuit (3), the electric proportional valve (2) switches to the first state, and the electric proportional valve (2) is powered off.

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