Flow control valve with flameout prevention function
By designing a flow control valve with anti-ignition function, the problem of difficult to limit the input power when the plunger pump receives feedback pressure from multiple valves is solved, and the output flow of the plunger pump is effectively controlled, which reduces the manufacturing cost and avoids the risk of engine shutting down the engine.
Patent Information
- Application Number
- CN202421090167.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-05-17
AI Technical Summary
When existing plunger pumps receive the LS feedback pressure of multiple valves, it is difficult to effectively limit their input power, resulting in the engine being slow to hold the vehicle and shut down. The constant power control valve has a complex structure and high manufacturing cost, which limits the development of application.
A flow control valve with anti-ignition function was designed. By canceling the constant power control module of the plunger pump, the structure was simplified, and the anti-insulation parts were used to cooperate with the flow control component to further control the output flow of the plunger pump to prevent the engine from shutting down.
It can not only meet the flow control characteristics, but also effectively limit the input power of the plunger pump, reduce manufacturing costs, promote the development of the application of the plunger pump, and avoid the risk of the engine shut-off.
Smart Images
Figure CN222668527U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a flow control valve with a flameout prevention function, belonging to the technical field of hydraulic plunger pumps. Background Art
[0002] The flow control valve can achieve precise control of the output flow of the variable piston pump. In the hydraulic system of the excavator using load-sensitive control, the flow control valve installed on the axial variable piston pump can achieve flow output control of the piston pump by receiving the feedback signal LS of the multi-way valve. There is a positive correlation between the LS feedback signal of the multi-way valve and the control angle of the pilot handle, that is, the larger the control angle of the pilot handle, the larger the LS feedback signal, and the smaller the control angle of the pilot handle, the smaller the LS feedback signal.
[0003] Traditional plunger pump flow control valve such as Figure 1 As shown, the flow control valve core 31 is installed in the valve body 1, the screw plug 2 with sealing function is installed on the right side, and the spring seat 37 that cooperates with the cone surface of the control valve core and supports the spring is provided on the left side. The feedback pressure oil channel 13 is used to receive the LS feedback signal from the multi-way valve, and the adjusting screw 36 is used to adjust the clamping force of the small spring 33 and the large spring 34. The load oil pressure oil channel 12 is the load pressure of the plunger pump, and the control oil channel 11 is the control pressure entering the servo variable cavity of the plunger pump to control the variable of the plunger pump.
[0004] like Figure 1 As shown in the figure, the force analysis of the control valve core 31 is carried out, and the load acts on the hydraulic pressure F on the right side of the control valve core 右 =P 负载 ×S, feedback pressure P LS The hydraulic pressure F on the left side of the control valve core 左 =P LS ×S, the spring force generated by the small spring 33 and the large spring 34 compressed by the adjusting screw 36 on the control valve core is F, so the balance condition of the control valve core 31 is F 右 =F 左 +F, when the force on the right side of the control valve core is greater than the sum of the feedback pressure force on the left side and the spring force, the control valve core 31 moves to the left, the load pressure oil in the load oil pressure channel 12 is connected to the control oil channel 11, enters the servo variable chamber of the plunger pump, and drives the plunger pump output flow to decrease; when the force on the right side of the control valve core 31 is less than the sum of the feedback pressure force on the left side and the spring force, the control valve core 31 moves to the right, the load oil pressure channel 12 is disconnected from the control oil channel 11, the load oil pressure cannot enter the servo variable control chamber of the plunger pump, and the plunger pump variable mechanism outputs a larger flow under the action of the reset spring. It can be seen that the flow valve receives the feedback pressure P of the multi-way valve. LS , the output flow of the plunger pump can be accurately adjusted.
[0005] Here, the plunger pump equipped with a flow control valve can only receive the LS feedback pressure of the multi-way valve to adjust the flow output of the plunger pump. However, for the actual application of the plunger pump, the power limit of the engine must also be considered, that is, the input power of the plunger pump cannot exceed the output power of the engine to avoid the problem of the engine slowing down and stalling. In order to solve this problem, the traditional plunger pump design usually adds a constant power control valve to the plunger pump to ensure that the input power of the plunger pump is always lower than the output power of the engine. This design can well solve the problem of the plunger pump stalling due to overpower, but the constant power control valve itself has a complex structure, high processing precision, and expensive manufacturing cost, which often limits the application and development of the plunger pump.
[0006] Therefore, the technical field urgently needs to develop a flow control valve with an anti-flashing function, which can not only meet the flow control characteristics, but also limit the input power of the plunger pump. By eliminating the constant power control module of the plunger pump, the structure is simplified and the manufacturing cost of the plunger pump is reduced. Utility Model Content
[0007] The technical problem to be solved by the utility model is that in order to ensure that the input power of the plunger pump does not exceed the output power of the engine while receiving the LS feedback pressure of the multi-way valve, so as to avoid the problem of the engine slowing down, stalling, etc., the existing plunger pump equipped with a flow control valve usually adopts a method of adding a constant power control valve to the plunger pump. However, the constant power control valve itself has a complex structure, high processing precision and expensive manufacturing cost, which often limits the application and development of the plunger pump.
[0008] In order to solve the above technical problems, the utility model provides a flow control valve with an anti-stall function, which can not only meet the flow control characteristics, but also limit the input power of the plunger pump. By eliminating the constant power control module of the plunger pump, the structure is simplified and the manufacturing cost of the plunger pump is reduced.
[0009] In order to achieve the above technical objectives and the above technical effects, this application is implemented through the following technical solutions:
[0010] A flow control valve with an anti-stall function comprises a valve body, the valve body is provided with a control oil passage, a load oil pressure oil passage, a feedback pressure oil passage, an oil port 1 and an oil port 2, the control oil passage is connected with the load oil pressure oil passage, a sealing screw plug is provided at one end of the load oil pressure oil passage away from the control oil passage, the feedback pressure oil passage is provided in the valve body and connected with the control oil passage, and the feedback pressure oil passage realizes pressure control through the cooperation of a multi-way valve and a pilot handle; the oil port 1 is connected with the oil port 2, the oil port 1 is used to connect with the oil outlet of an external pilot pump, the oil port 2 is used to connect with the oil source valve block of the hydraulic system of an excavator, the oil port 1 is connected with the control oil passage through the oil passage 1, and the oil port 2 is connected with the control oil passage through the oil passage 2;
[0011] It also includes a flow control component, which is arranged in the control oil channel and the load oil pressure oil channel to control and adjust the output flow of the plunger pump;
[0012] The anti-stall component, oil port 1 and oil port 2 are connected through the anti-stall component and are used to cooperate with the flow control component to further control the output flow of the plunger pump to prevent the engine from stalling.
[0013] Preferably, the flow control assembly includes a control valve core, a spacer, a small spring, a large spring, a nut, an adjusting screw, a spring seat and a large nut. The control valve core is slidably arranged in the valve body, and one end of the control valve core extends into the load oil pressure oil channel, and the other end extends into the control oil channel. The load oil pressure in the load oil pressure oil channel acts on the end of the control valve core extending into the control oil channel through the small hole inside the control valve core. The control valve core is provided with a shoulder for controlling the load oil pressure oil channel and controlling the opening and closing of the oil channel; the spacer is fixedly arranged in the control oil channel to support the control valve core, and the small spring sleeve is arranged on the control The outside of the control valve core cooperates with the inner wall of the control oil channel to generate a spring force on the control valve core that deviates from the direction of the load oil pressure oil channel; the nut is threadedly connected to the inner wall of the control oil channel opening and has an oil hole connected to the feedback pressure oil channel on the outer wall. The control valve core extends into the nut, one end of the adjusting screw is threadedly connected to the inner wall of the nut, and the other end extends out of the valve body. The spring seat is arranged in the nut and one end abuts against the end face of the control valve core. The large spring is arranged between the end face of the adjusting screw and the spring seat. The large nut is threadedly connected to one end of the adjusting screw extending out of the valve body for tightening the nut.
[0014] Furthermore, the load oil pressure in the load oil pressure oil channel generates a load liquid pressure toward one end of the control oil channel on the control valve core, the small spring generates a spring force one toward one end of the control oil channel on the control valve core, the feedback pressure oil channel generates a feedback force toward one end of the load oil pressure oil channel on the end of the control valve core extending into the control oil channel, the adjusting screw compresses the large spring and generates a spring force two toward one end of the load oil pressure oil channel on the control valve core, and when the control valve core keeps balanced, the sum of the load liquid pressure and the spring force one is equal to the sum of the feedback force and the spring force two.
[0015] Furthermore, the end surface of one end of the control valve core extending into the control oil channel is a conical surface, and the end surface of the spring seat cooperates with the conical surface of the control valve core.
[0016] Furthermore, a sealing ring is provided on the outer wall of the nut to form a sealing effect with the inner wall of the control oil channel, and the nut presses the spacer toward one end surface of the spacer and cooperates with the inner wall of the control oil channel to limit the spacer.
[0017] Furthermore, a small nut is threadedly connected to the outer wall of one end of the adjusting screw extending out of the valve body. The small nut is located at the end of the large nut away from the valve body and is used to tighten the adjusting screw.
[0018] Preferably, the flameout prevention component comprises a throttling screw, the throttling screw is threadedly connected between the oil port 1 and the oil port 2, and the pilot pump is a metering pump.
[0019] The utility model provides a flow control valve with flameout prevention function, which has the following advantages:
[0020] When the utility model is used, it can not only meet the flow control characteristics, but also limit the input power of the plunger pump. By eliminating the constant power control module of the plunger pump, the structure is simplified, the manufacturing cost of the plunger pump is reduced, and it plays an important role in the application and promotion of the plunger pump. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 It is a schematic diagram of the cross-sectional structure of a plunger pump flow control valve in the prior art;
[0022] Figure 2 This is a full cross-sectional schematic diagram of the overall structure of a flow control valve with an anti-flameout function that is mainly embodied in the utility model;
[0023] In the figure:
[0024] 1-valve body; 11-control oil channel; 12-load oil pressure oil channel; 13-feedback pressure oil channel; 14-oil port 1; 15-oil channel 1; 16-oil port 2; 17-oil channel 2; 2-screw plug; 3-flow control assembly; 31-control valve core; 311-shoulder; 32-spacer; 33-small spring; 34-large spring; 35-nut; 351-oil hole; 36-adjusting screw; 37-spring seat; 38-large nut; 4-anti-flameout component; 5-small nut. DETAILED DESCRIPTION
[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technical personnel in the field without creative work are within the scope of protection of the present utility model.
[0026] Reference Figure 2A flow control valve with an anti-stall function comprises a valve body 1, wherein a control oil passage 11, a load oil pressure oil passage 12, a feedback pressure oil passage 13, an oil port 14 and an oil port 2 16 are integrally injection molded in the valve body 1, the control oil passage 11 is connected with the load oil pressure oil passage 12, and a screw plug 2 for sealing the load oil pressure is screwed on one end of the load oil pressure oil passage 12 away from the control oil passage 11, and the feedback pressure oil passage 13 is arranged in the valve body 1 and connected with the control oil passage 11, and the feedback pressure oil passage 13 realizes pressure control through the cooperation of a multi-way valve and a pilot handle; the oil port 14 is connected with the oil port 2 16, the oil port 14 is used to connect to the oil outlet of an external pilot pump, the oil port 2 16 is used to connect to the oil source valve block of the hydraulic system of an excavator, the oil port 14 is connected with the control oil passage 11 through the oil passage 15, and the oil port 2 16 is connected with the control oil passage 11 through the oil passage 2 17.
[0027] Reference Figure 2 A flow control valve with an anti-stall function also includes a flow control component 3 and an anti-stall component 4. The flow control component 3 is installed in a control oil passage 11 and a load oil pressure oil passage 12 to control and adjust the output flow of the plunger pump. The oil port 14 and the oil port 2 16 are connected through the anti-stall component 4 to cooperate with the flow control component 3 to further control the output flow of the plunger pump to prevent the engine from stalling.
[0028] In a further embodiment, the flow control assembly 3 includes a control valve core 31, a spacer sleeve 32, a small spring 33, a large spring 34, a nut 35, an adjusting screw 36, a spring seat 37 and a large nut 38. The control valve core 31 is slidably installed in the valve body 1, and can move flexibly left and right without being stuck. One end of the control valve core 31 extends into the load oil pressure oil channel 12, and the other end extends into the control oil channel 11. The load oil pressure in the load oil pressure oil channel 12 acts on the end of the control valve core 31 extending into the control oil channel 11 through the small hole inside the control valve core 31. The control valve core 31 is integrally formed with a shoulder 311 for controlling the load oil pressure oil channel 12 and the control oil channel 11 to open and close; the spacer sleeve 32 is fixedly installed in the control oil channel 11 to support the control valve core 31, and the small spring 33 is sleeved outside the control valve core 31 and cooperates with the inner wall of the control oil channel 11 to generate a spring force on the control valve core 31 that is away from the load oil pressure oil channel 12.
[0029] The nut 35 is threadedly screwed on the inner wall of the opening of the control oil channel 11 and an oil hole 351 connected to the feedback pressure oil channel 13 is opened on the outer wall. The control valve core 31 is penetrated by the spacer 32 and extends into the nut 35. A sealing ring is installed on the outer wall of the nut 35 to form a sealing effect with the inner wall of the control oil channel 11. The nut 35 presses the spacer 32 toward one end face of the spacer 32 and cooperates with the inner wall of the control oil channel 11 to limit the spacer 32. One end of the adjusting screw 36 is threadedly connected to the inner wall of the nut 35, and the other end extends out of the valve body 1. The spring seat 37 is installed in the nut 35 and one end abuts against the end face of the control valve core 31. The large spring 34 is installed between the end face of the adjusting screw 36 and the spring seat 37, and the compression force on the large spring 34 can be adjusted by rotating the adjusting screw 36. The large nut 38 is threadedly connected to one end of the adjusting screw 36 extending out of the valve body 1 to tighten the nut 35.
[0030] In a further embodiment, a small nut 5 is threadedly connected to the outer wall of one end of the adjusting screw 36 extending out of the valve body 1 . The small nut 5 is located at the end of the large nut 38 away from the valve body 1 and is used to tighten the adjusting screw 36 .
[0031] Reference Figure 2 In a further embodiment, a sealing ring is installed on the outer wall of the adjusting screw 36 for sealing the hydraulic oil. The end face of the control valve core 31 extending into the control oil channel 11 is a conical surface, and the end face of the spring seat 37 cooperates with the conical surface of the control valve core 31, so that the spring seat 37 is more stable when the control valve core 31 moves under thrust.
[0032] Furthermore, the flameout prevention component 4 includes a throttling screw, which is threadedly connected between the oil port 14 and the oil port 2 16. The oil port 14 and the oil port 2 16 flow through the throttling hole of the throttling screw, and the pilot pump is a quantitative pump.
[0033] The control principle of the flow control valve with flameout prevention function of the utility model is as follows:
[0034] The load oil pressure in the load oil pressure passage 12 generates a load hydraulic pressure toward one end of the control oil passage 11 on the control valve core 31. The load hydraulic pressure F 负载 =P 负载 ×S, the small spring 33 exerts a spring force F0 on the control valve core 31 toward one end of the control oil passage 11, and the feedback pressure oil passage 13 exerts a feedback force on the end of the control valve core 31 extending into the control oil passage 11 toward one end of the load oil pressure oil passage 12. The feedback force F LS =p LS ×S, the adjusting screw 36 compresses the large spring 34 to generate a spring force F1 on the control valve core 31 toward one end of the load oil pressure channel 12. When the control valve core 31 maintains balance, F 负载 +F0=F LS +F1.
[0035] When the pilot handle is operated to a larger angle, the feedback pressure increases, and the sum of the feedback force and the second spring force is greater than the sum of the load hydraulic pressure and the first spring force. The control valve core 31 moves toward the load oil pressure passage 12. The load oil pressure passage 12 and the control oil passage 11 are covered by the shoulder 311. The load oil pressure in the load oil pressure passage 12 cannot enter the control oil passage 11. Under the action of the return spring in the internal displacement control module, the output flow of the plunger pump increases.
[0036] When the pilot handle is operated to a smaller angle, the feedback pressure becomes smaller, and the sum of the feedback force and the spring force 2 is less than the sum of the load fluid pressure and the spring force 1. The control valve core 31 moves toward the control oil channel 11. At this time, the shoulder 311 moves away from the load oil pressure channel 12, so that the load oil pressure channel 12 is connected to the control oil channel 11. The load oil pressure in the load oil pressure channel 12 enters the control oil channel 11, pushing the servo variable valve core to overcome the reset spring in the variable system module, and the output flow of the plunger pump is reduced.
[0037] Oil port 1 14 is connected to the oil outlet of the pilot pump, and oil port 2 16 is connected to the oil source valve block. The outlet oil of the pilot pump enters the valve body 1 through oil port 14, flows through the throttle hole of the anti-stallation component 4, and flows into the oil source valve block from oil port 2 16. The set pressure of the oil source valve block of the excavator hydraulic system is 4MPa. At the same time, the output oil of the pilot pump flows through the two ends of the control valve core 31 through oil channel 1 15 and oil channel 2 17.
[0038] When the engine is not stalled, the engine speed is constant, the output flow of the pilot pump is set to Q, the output oil of the pilot pump enters the valve body 1 through the oil port 14, the oil pressure in the oil port 2 16 and the oil channel 2 17 is 4MPa, due to the existence of the throttle hole on the anti-stall component 4, the output flow Q of the pilot pump forms a pressure loss ΔP at the throttle hole, the pressure in the oil port 14 and the oil channel 15 is 4MPa+ΔP, and the oil channel 15 exerts a force F3 on the control valve core 31 toward the load oil pressure oil channel 12 =(4+ΔP)×S1 is greater than the force F2=4×S1 generated by the oil passage 17 on the control valve core 31 toward the control oil passage 11, thereby pushing the control valve core 31 to move toward the load oil pressure oil passage 12. The load oil pressure oil passage 12 and the control oil passage 11 are covered by the shoulder 311. The load oil pressure in the load oil pressure oil passage 12 cannot enter the control oil passage 11. Under the action of the return spring in the internal displacement control module, the output flow of the plunger pump becomes larger, thereby giving full play to the efficiency of the engine.
[0039] When the engine is overloaded and slows down, the engine speed drops, and the output flow of the pilot pump is set to Q1. Q1 is less than Q. The oil pressure in the oil port 16 and the oil channel 17 is 4MPa and remains unchanged. The output flow Q1 of the pilot pump forms a pressure loss ΔP1 at the throttle hole. Since Q1 is less than Q, ΔP1 is also less than ΔP. At this time, for the balanced control valve core 31, the force of the oil channel 15 on the control valve core 31 toward the load oil pressure oil channel 12 is F3 = (4 + ΔP1) × S 1, because ΔP1 gradually decreases, F3 also decreases, and the force F2=4×S1 generated by the oil passage 17 on the control valve core 31 toward the control oil passage 11 remains unchanged, so that the control valve core 31 moves toward the control oil passage 11, and the load oil pressure in the load oil pressure oil passage 12 enters the control oil passage 11, pushing the servo variable valve core to overcome the return spring in the variable system module, and the output flow of the plunger pump is reduced, that is, the engine is stalled, and the output flow of the plunger pump is reduced to prevent the engine from stalling.
[0040] The above is only a preferred embodiment of the utility model, and is not any formal or substantial limitation of the utility model. It should be pointed out that ordinary technicians in this technical field can make some improvements and supplements without departing from the utility model, and these improvements and supplements should also be regarded as the protection scope of the utility model. Any technician familiar with this profession can make some changes, modifications and equivalent changes made by using the technical content disclosed above without departing from the spirit and scope of the utility model, which are all equivalent embodiments of the utility model; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the utility model are still within the scope of the technical solution of the utility model.
Claims
1. A flow control valve with flameout prevention function, characterized in that: It comprises a valve body, on which a control oil passage, a load oil pressure oil passage, a feedback pressure oil passage, an oil port 1 and an oil port 2 are provided, the control oil passage is connected with the load oil pressure oil passage, a sealing screw plug is provided at one end of the load oil pressure oil passage away from the control oil passage, the feedback pressure oil passage is provided in the valve body and connected with the control oil passage, and the feedback pressure oil passage realizes pressure control through the cooperation of a multi-way valve and a pilot handle; the oil port 1 is connected with the oil port 2, the oil port 1 is used to connect with the oil outlet of an external pilot pump, the oil port 2 is used to connect with the oil source valve block of the hydraulic system of the excavator, the oil port 1 is connected with the control oil passage through the oil passage 1, and the oil port 2 is connected with the control oil passage through the oil passage 2; It also includes a flow control component, which is arranged in the control oil channel and the load oil pressure oil channel to control and adjust the output flow of the plunger pump; The anti-stall component, oil port 1 and oil port 2 are connected through the anti-stall component and are used to cooperate with the flow control component to further control the output flow of the plunger pump to prevent the engine from stalling.
2. A flow control valve with flameout prevention function as claimed in claim 1, characterized in that: The flow control assembly includes a control valve core, a spacer, a small spring, a large spring, a nut, an adjusting screw, a spring seat and a large nut. The control valve core is slidably arranged in the valve body, and one end of the control valve core extends into the load oil pressure oil channel, and the other end extends into the control oil channel. The load oil pressure in the load oil pressure oil channel acts on the end of the control valve core extending into the control oil channel through the small hole inside the control valve core. The control valve core is provided with a shoulder for controlling the load oil pressure oil channel and controlling the opening and closing of the oil channel; the spacer is fixedly arranged in the control oil channel to support the control valve core, and the small spring sleeve is arranged on the control valve The outer wall of the core cooperates with the inner wall of the control oil channel to generate a spring force on the control valve core that deviates from the direction of the load oil pressure oil channel; the nut is threadedly connected to the inner wall of the control oil channel opening and has an oil hole connected to the feedback pressure oil channel on the outer wall. The control valve core extends into the nut, one end of the adjusting screw is threadedly connected to the inner wall of the nut, and the other end extends out of the valve body. The spring seat is arranged in the nut and one end abuts against the end face of the control valve core. The large spring is arranged between the end face of the adjusting screw and the spring seat. The large nut is threadedly connected to one end of the adjusting screw extending out of the valve body for tightening the nut.
3. A flow control valve with flameout prevention function as claimed in claim 2, characterized in that: The load oil pressure in the load oil pressure oil channel generates a load liquid pressure toward one end of the control oil channel on the control valve core, the small spring generates a spring force one toward one end of the control oil channel on the control valve core, the feedback pressure oil channel generates a feedback force toward one end of the load oil pressure oil channel on the end of the control valve core extending into the control oil channel, the adjusting screw compresses the large spring and generates a spring force two toward one end of the load oil pressure oil channel on the control valve core, when the control valve core keeps balanced, the sum of the load liquid pressure and the spring force one is equal to the sum of the feedback force and the spring force two.
4. A flow control valve with flameout prevention function as claimed in claim 2, characterized in that: The end surface of one end of the control valve core extending into the control oil passage is a conical surface, and the end surface of the spring seat matches the conical surface of the control valve core.
5. A flow control valve with flameout prevention function as claimed in claim 2, characterized in that: A sealing ring is arranged on the outer wall of the nut to form a sealing effect with the inner wall of the control oil passage. The nut presses the spacer toward one end surface of the spacer and cooperates with the inner wall of the control oil passage to limit the spacer.
6. A flow control valve with flameout prevention function as claimed in claim 2, characterized in that: A small nut is threadedly connected on the outer wall of one end of the adjusting screw extending out of the valve body. The small nut is located at the end of the large nut away from the valve body and is used to tighten the adjusting screw.
7. A flow control valve with flameout prevention function as claimed in claim 1, characterized in that The flameout prevention component includes a throttling screw, the throttling screw is threadedly connected between the oil port 1 and the oil port 2, and the pilot pump is a quantitative pump.