A bidirectional adjustable control valve structure

Abstract

The application relates to a bidirectional adjusting control valve structure and belongs to the technical field of engineering mechanical equipment. The control valve comprises a main valve rod, a valve core and adjusting screw No. 2; one end of the main valve rod is provided with adjusting screw No. 2; the middle part of the main valve rod is vertically provided with the valve core; the other end of the main valve rod is provided with an adjusting mechanism for ensuring that the output flow of front and rear tandem pumps is consistent when the vehicle is in reverse; and the adjusting mechanism is arranged in the axial direction of the main valve rod. The control valve provided by the application can not only adjust the coincidence of the output flow of the plunger pump when moving forward, but also adjust the coincidence of the output flow of the plunger pump when moving backward, so that the machine control performance is optimized and the product performance is improved.

Description

Technical Field

[0001] This invention relates to a bidirectional adjustable control valve structure, belonging to the technical field of engineering machinery equipment. Background Technology

[0002] The control valve is a crucial component in the piston pump's variable displacement mechanism. It receives the external load pressure signal from the piston pump and, based on its internal servo feedback mechanism, adjusts the pump's output flow rate to match the engine's output power (p(power) = Q(flow rate) × P(pressure)). This prevents underutilization of engine power, avoiding energy waste, or excessive input power causing engine stalling. The servo feedback mechanism adjusts the flow output by regulating the pre-compression of the control spring based on the engine's maximum output power. When the external load reaches a preset pressure, the servo mechanism reduces the piston pump's displacement to ensure the product of the output flow rate and load pressure is less than the engine's output power, preventing stalling. Conversely, when the external load pressure is lower, the control spring compression is less, and the servo feedback mechanism increases the piston pump's displacement to make the product of the output flow rate and load pressure close to the engine's output power, ensuring system operation and maximizing engine energy utilization.

[0003] In closed-loop hydraulic systems using piston pumps for driving, the left and right travel motors are driven by two tandem pumps. To ensure the vehicle travels at a consistent speed, the output flow of the two tandem pumps must remain constant under a given load. This places high demands on the servo feedback mechanism of the piston pump control valve. If the front and rear tandem pumps receive the same load signal but their output flow deviates, the mechanical movement will tilt towards the slower side, which is unacceptable. Traditional designs typically incorporate auxiliary adjustment mechanisms to ensure consistent piston output flow under the same load. Figure 1-3As shown, when control valve X1 receives a signal from the load hydraulic oil driving the motor forward, hydraulic oil enters end A of the main valve stem 1, driving the main valve stem 1 to move to the right. Valve core 9 is locked to the main valve stem 1 via a threaded connection. When the main valve stem 1 moves, valve core 9 rotates. The rotation angle of valve core 9 corresponds to the output flow rate of the plunger pump. Adjusting the spring compression of adjusting screw 10 can adjust the rotation angle of the valve core, ensuring consistent output flow rates for the plunger pumps controlled by the forward-moving tandem pumps. When control valve X2 receives a signal from the load hydraulic oil driving the motor backward, hydraulic oil enters end B of the main valve stem 1, pushing the main valve stem 1 to move to the left. The rotation direction of valve core 9 changes. At this time, the angle of valve core 9 is entirely determined by the load pressure and spring stiffness. The output flow rate controlled by the forward and backward tandem pumps cannot be adjusted; it can only be guaranteed by spring stiffness and component machining accuracy, making it difficult to achieve consistent output flow rates. Since mobile machinery needs to move in both forward and backward directions, conventionally designed control valves only have an auxiliary adjustable structure in the forward direction to ensure consistent flow in that direction. However, they fail to ensure consistent flow in the backward direction, causing the machine to deviate during backward movement and affecting the overall operating performance.

[0004] Therefore, there is an urgent need in this technical field to develop a bidirectional adjustable control valve structure. This structure should allow for adjustable output flow rates of the front and rear pumps when the vehicle is moving forward, and also allow for adjustable output flow rates of the front and rear pumps when the vehicle is moving backward, ensuring consistent flow rates and preventing deviation that could affect the overall machine's performance. Given the current market trend of customers demanding superior driving experience and high-performance products, developing a bidirectional adjustable control valve structure is now imperative. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem of how to make the output flow of the front and rear pumps adjustable when driving the vehicle forward, and also make the output flow of the front and rear pumps adjustable when the vehicle moves backward, so as to ensure the consistency of the flow and avoid the technical problem of deviation.

[0006] To address the aforementioned problems, the present invention provides a bidirectional adjustable control valve structure, comprising a main valve stem, a valve core, and a second adjusting screw; one end of the main valve stem is provided with the second adjusting screw; the valve core is vertically positioned in the middle of the main valve stem; the other end of the main valve stem is provided with an adjusting mechanism for ensuring consistent output flow between the front and rear tandem pumps when the vehicle reverses; the adjusting mechanism includes an elastic mechanism that abuts against the other end of the main valve stem.

[0007] Preferably, the adjusting mechanism is arranged along the axial direction of the main valve stem.

[0008] Preferably, the adjusting mechanism includes a spring, a spring seat, and a screw; the outer periphery of the main valve stem at the end away from the adjusting screw is provided with a stepped structure; a spring is sleeved on the outer periphery of the main valve stem, one end of the spring abuts against the stepped structure, and the other end of the spring is provided with a spring seat; one end of the spring seat corresponds to the end of the main valve stem, and the other end of the spring seat abuts against one end of the screw that passes through the control valve body.

[0009] Preferably, the screw one coincides with the central axis of the main valve stem.

[0010] Preferably, the other end of the screw is configured as an external hexagonal screw structure to facilitate the movement of the screw towards the main valve stem; the screw is threadedly connected to the control valve, and a nut is fitted onto the other end of the screw located outside the control valve.

[0011] Preferably, a nut is fitted around the outer periphery of the spring seat.

[0012] Preferably, the nut is fixed in the control valve body by threads, and an O-ring is provided between the nut and the valve body.

[0013] Preferably, an O-ring is provided between the outer periphery of the spring seat and the inner wall of the nut.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The control valve provided by this invention can not only adjust the overlap of the output flow of the plunger pump in the forward driving direction, but also adjust the overlap of the output flow of the plunger pump in the backward driving direction, which plays an important role in optimizing the overall machine's operability and improving product performance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of an existing control valve;

[0017] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the middle AA section;

[0018] Figure 3 for Figure 2 Schematic diagram of BB cross-section structure;

[0019] Figure 4 This is a schematic diagram of the external structure of a bidirectional adjustable control valve provided in an embodiment of the present invention;

[0020] Figure 5 for Figure 4 Schematic diagram of the cross-sectional structure of the middle AA section;

[0021] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure of the middle BB section;

[0022] Reference numerals in the attached diagram: 1. Main valve stem; 2. Spring; 3. Nut; 4. Spring seat; 5. O-ring one; 6. O-ring two; 7. Nut; 8. Screw one; 9. Valve core; 10. Adjusting screw two. Detailed Implementation

[0023] To make the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0024] like Figure 1-6 As shown, this invention provides a bidirectional adjustable control valve structure, which includes a main valve stem 1, a valve core 9, and an adjusting screw 10. One end of the main valve stem 1 is provided with the adjusting screw 10; the valve core 9 is vertically positioned in the middle of the main valve stem 1; the other end of the main valve stem 1 is provided with an adjusting mechanism to ensure consistent output flow between the front and rear tandem pumps when the vehicle reverses. The adjusting mechanism includes an elastic mechanism that abuts against the other end of the main valve stem 1; the adjusting mechanism is axially arranged along the main valve stem 1; the adjusting mechanism includes a spring 2, a spring seat 4, and a screw 8; the outer periphery of the main valve stem 1 at the end away from the adjusting screw 10 is designed with a stepped structure; the outer periphery of the main valve stem 1 is fitted with a spring 2, one end of which abuts against the stepped structure, and the other end of the spring 2 is provided with a spring seat 4; one end of the spring seat 4 corresponds to the end of the main valve stem 1, and the other end of the spring seat 4 abuts against one end of the screw 8, which passes through the valve body of the control valve. The screw 8 coincides with the central axis of the main valve stem 1. The other end of screw 8 is designed as an external hexagonal screw structure to facilitate the adjustment of screw 8 towards the main valve stem 1; screw 8 is threadedly connected to the control valve, and a nut 7 is fitted onto the other end of screw 8 outside the control valve. A nut 3 is fitted onto the outer circumference of spring seat 4. Nut 3 is threadedly fixed to the control valve body, and an O-ring 6 is provided between nut 3 and valve body. An O-ring 5 is provided between the outer circumference of spring seat 4 and the inner wall of nut 3.

[0025] Example

[0026] like Figure 4-6 As shown, this invention provides a bidirectional adjustable control valve structure, including a main valve stem 1, a spring 2, a nut 3, a spring seat 4, an O-ring 5, an O-ring 6, a nut 7, and a screw 8. The left side of the main valve stem 1 is designed with a stepped structure, and the stepped surface is used to fix and place the spring 2. The nut 3 is locked to the control valve body by threads, and the O-ring 6 forms an angle seal with the valve body to seal the hydraulic oil. The spring seat 4 is installed in the inner hole of the nut 3, and the outer circle of the spring seat 4 has a square groove to place the O-ring 5, which forms a cylindrical seal with the inner hole of the nut 3 to seal the hydraulic oil. The nut 7 is used to lock the screw 8, which plays a role in preventing loosening. The screw 8 is an external hexagonal screw structure, and the threads are used to adjust the pre-compression of the spring 2.

[0027] This embodiment provides a control valve for driving a traveling piston pump; see [link / reference]. Figure 5The main valve stem 1 is designed with a stepped shape on the left side to accommodate and fix the spring 2. The nut 3 is threaded onto the control valve body and the hydraulic oil is sealed by an O-ring 6. The spring seat 4 is placed in the nut 3 to abut against the left end of the supporting spring 2. The O-ring 5 seals the hydraulic oil leaking from the outer circle of the spring seat 4 and the inner hole of the nut 3. The pre-compression of the spring 2 can be adjusted by adjusting the hexagonal outer diameter of the adjusting screw 8. The nut 7 locks the screw 8 to prevent it from loosening and causing changes in the pre-compression of the spring 2.

[0028] The working process of this embodiment is as follows:

[0029] When control valve X1 receives a load hydraulic oil signal, the hydraulic oil enters control valve A chamber, pushing the main valve stem 1 to the right. Since valve core 9 and main valve stem 1 are linked, the movement of main valve stem 1 causes valve core 9 to rotate. The angle of rotation of valve core 9 determines the output flow rate of the plunger pump. Therefore, the left side of main valve stem 1 is subjected to hydraulic pressure, overcoming the spring force of the adjustable structure on the right side, causing main valve stem 1 to move to the right, valve core 9 to rotate, and the plunger pump to output displacement. Due to variations in spring stiffness and part machining accuracy, it is difficult for the two control valves to achieve consistent output flow rates for the plunger pump under the same load. Therefore, by adjusting the adjusting screw 10 on the right side, the output flow rates of the plunger pumps can be kept consistent between the front and rear tandem pump control valves under the same load, preventing the machine from veering off course when moving forward.

[0030] Similarly, the optimized control valve structure provided by this invention adds an auxiliary adjustable structure to the control valve during machine reversal operation to ensure consistent output flow of the plunger pump during reversal. Specifically, when port X2 (reversal operation port) receives a reversal load signal, hydraulic oil enters chamber B of the control valve, pushing the main valve stem 1 to the left. The valve core 9 rotates in a different direction, and the output flow direction also changes simultaneously, achieving reverse drive of the walking device. To ensure consistent output flow of the plunger pump under the same load conditions, relying solely on the original structure's machining precision and spring stiffness is insufficient. Therefore, when the main valve stem 1 moves to the left, adjusting screw 8 moves the spring seat 4 to the right, compressing the spring 2 to adjust the valve core's rotation angle. This ensures that the output flow of the plunger pump is adjustable and consistent under the same load conditions when the control valves of the front and rear tandem pumps control the reversal operation, preventing deviation during reversal.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A bidirectional adjustable control valve structure, comprising a main valve stem, a valve core, and a second adjusting screw; the second adjusting screw is provided at one end of the main valve stem; the valve core is vertically provided in the middle of the main valve stem; characterized in that, The other end of the main valve stem is provided with an adjustment mechanism to ensure that the output flow of the front and rear tandem pumps remains consistent when the vehicle reverses; the adjustment mechanism includes an elastic mechanism that abuts against the other end of the main valve stem; The adjusting mechanism is arranged along the axial direction of the main valve stem; The adjusting mechanism includes a spring, a spring seat, and a screw rod. The outer periphery of the main valve rod at the end away from the adjusting screw rod is designed with a stepped structure. A spring is sleeved on the outer periphery of the main valve rod, with one end of the spring abutting against the stepped structure and the other end of the spring having a spring seat. One end of the spring seat corresponds to the end of the main valve rod, and the other end of the spring seat abuts against one end of the screw rod that passes through the control valve body. A nut is fitted around the outer periphery of the spring seat; The nut is fixed in the control valve body by threads, and an O-ring is provided between the nut and the valve body; An O-ring is provided between the outer periphery of the spring seat and the inner wall of the nut; The other end of the screw is configured as an external hexagonal screw structure to facilitate the adjustment of the screw moving towards the main valve stem; the screw is threadedly connected to the control valve, and a nut is fitted onto the other end of the screw located outside the control valve.

2. The bidirectional adjustable control valve structure according to claim 1, characterized in that, The screw 1 coincides with the central axis of the main valve stem.

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