A differential pressure balanced oil drain valve, a control valve assembly, and an electric pump station

Abstract

This utility model relates to the field of horizontal jack manufacturing technology, and in particular to a differential pressure balanced oil discharge valve, a control valve assembly, and an electric pump station. The differential pressure balanced oil discharge valve is the core component for achieving smooth jack descent, and includes a valve body, a valve core assembly, a pressure balancing mechanism, and a drive assembly. The valve body has a first oil passage and a second oil passage; the inner valve core of the valve core assembly has a pressure balancing channel, and an elastic reset element provides initial sealing pre-tightening force; the pressure balancing mechanism seals the pressure balancing channel through a sealing body. The drive assembly employs a two-stage control: the first stage pushes the pusher to open the sealing body, initially connecting the first and second oil passages, balancing the oil pressure, and reducing the pressure difference of the inner valve core; the second stage directly acts on the inner valve core, causing it to overcome the pre-tightening force to fully connect the first and second oil passages, achieving smooth hydraulic oil return, ensuring stable and vibration-free jack descent, while reducing operating force and improving safety and convenience.

Description

Technical Field

[0001] This utility model relates to the field of horizontal jack manufacturing technology, and in particular to a differential pressure balanced oil drain valve, a control valve assembly, and an electric pump station. Background Technology

[0002] Electro-hydraulic horizontal jacks are widely used in bridge erection, vehicle repair, and heavy equipment installation. They achieve smooth lifting and precise control of heavy objects through a hydraulic system. During operation, the drain valve, as the core component controlling the jack's descent, plays a crucial role in ensuring the return of hydraulic oil and the smooth descent of the load.

[0003] Traditional electric hydraulic jacks mostly use a single-valve-core spring-loaded discharge valve, which allows hydraulic oil to flow back by directly opening the valve core manually or mechanically. However, this design has many drawbacks: First, the valve core opening causes a violent flow fluctuation, resulting in jerkiness during jack descent and affecting operational safety; second, the nonlinearity of the spring stiffness and friction during valve core movement make it difficult to precisely control the opening and closing of the discharge valve, potentially leading to unstable descent speed; third, to ensure sealing under high pressure, the spring preload is usually large, requiring significant operating force for discharge, making it inconvenient to use.

[0004] While existing improved drain valves can partially solve the above problems, they still have limitations. For example, pilot-operated drain valves reduce the valve core opening force through a pilot structure, but their complex structure increases manufacturing costs. Furthermore, in harsh construction environments, pilot valves are prone to oil clogging, affecting reliability. Multi-stage drain valves, while able to control flow in stages and reduce impact, are bulky and have complex valve core linkage control, making them difficult to adapt to the compact structure of horizontal jacks. Therefore, it is urgent for technical personnel to solve these problems. Utility Model Content

[0005] This utility model provides a differential pressure balanced oil discharge valve, which aims to solve the problems of large flow fluctuation, low control accuracy, large operating force and complex structure of traditional hydraulic oil discharge valves during operation.

[0006] This utility model relates to a differential pressure balanced oil discharge valve, which includes:

[0007] The valve body has a first oil passage and a second oil passage formed inside.

[0008] The valve core assembly, located within the valve body, includes an axially movable inner valve core and an elastic reset element; the inner valve core has a through pressure balance channel; the elastic reset element provides a preload force to cause the inner valve core to block the initial sealing path between the first oil passage and the second oil passage;

[0009] The pressure balancing mechanism includes an axially movable pusher and a sealing body; in the initial state, the sealing body blocks the pressure balancing channel under the combined action of the pre-tightening force of the elastic reset element and the hydraulic pressure of the first oil passage.

[0010] The drive assembly is configured to sequentially transmit axial drive force to the seal and the inner valve core;

[0011] The action process of the driving component triggers the following actions in sequence:

[0012] First stage: The drive component pushes the pusher, causing the seal to release the blockage of the pressure balance channel. The first oil passage and the second oil passage are connected through the pressure balance channel to achieve oil pressure balance.

[0013] Second stage: The drive component continues to operate and acts directly on the inner valve core, which is able to overcome the preload and move axially. The first oil passage and the second oil passage are connected through the flow path formed after the inner valve core is moved.

[0014] As a further improvement to the technical solution disclosed in this utility model, the drive component can only contact the inner valve core and push it to move when the pusher moves to completely release the seal from blocking the pressure balance channel.

[0015] As a further improvement to the technical solution disclosed in this utility model, the drive assembly includes a power output section and a linkage rod. The linkage rod is rigidly connected to the pusher and forms an axial movement gap with the inner valve core, and the distance of the axial movement gap is greater than the displacement required for the seal to release the seal.

[0016] As a further improvement to the technical solution disclosed in this utility model, the linkage rod and the pushing component are preferably integrally formed or connected by threads.

[0017] As a further improvement to the technical solution disclosed in this utility model, the power output unit is at least one of an electromagnetic drive unit, a hydraulic drive unit, or a manual operation unit.

[0018] As a further improvement to the technical solution disclosed in this utility model, the minimum cross-sectional area of ​​the flow path formed after the inner valve core is displaced is 8 to 10 times the cross-sectional area of ​​the pressure balance channel.

[0019] As a further improvement to the technical solution disclosed in this utility model, the diameter of the pressure balance channel is 1 to 3 mm; the diameter of the sealing body is 2 to 5 times the diameter of the pressure balance channel; and the elastic reset element is a compression spring with a preload force of 50 to 300 N.

[0020] As a further improvement to the technical solution disclosed in this utility model, the sealing body and the inlet end of the pressure balance channel form a conical seal, and the cone angle α is 60 to 120°, and the surface roughness Ra ≤ 0.4 μm.

[0021] Furthermore, this utility model also relates to a control valve assembly, which includes:

[0022] The valve block has a first and a second main oil passage inside.

[0023] At least two functional valve units are arranged in parallel within the valve block; at least one of the functional valve units is the aforementioned differential pressure balanced drain valve;

[0024] The first and second master oil passages are respectively connected to the corresponding interfaces of the functional valve units to form independent and parallel controllable multi-channel working oil circuits.

[0025] In addition, this utility model also relates to an electric pump station, including a motor, an oil pump, an oil tank, and a hydraulic cylinder. The motor drives the oil pump to operate, pressurizing the hydraulic oil in the oil tank and delivering it to the hydraulic cylinder. The oil pump includes a pump body and a control valve assembly. The control valve assembly is integrated into the pump body and is used to control the hydraulic cylinder pressure oil to flow back to the oil tank sequentially through the first oil passage and the second oil passage during the jack descent.

[0026] In practical applications, the differential pressure balanced oil drain valve disclosed in this utility model can achieve at least the following beneficial technical effects, specifically:

[0027] 1) By employing a step-by-step control method of "balancing oil pressure first, then opening the main channel," flow fluctuations are effectively eliminated, resolving the jitter issue during the jack's descent and significantly improving the control precision of the descent speed. The drive assembly first pushes the jacking component to release the seal from the pressure balancing channel, allowing hydraulic oil to slowly return through the channel and gradually balance the oil pressure on both sides of the valve core. Based on this, in the second stage, when the inner valve core is pushed to open the main flow path, the flow rate changes smoothly, with fluctuations controlled within a reasonable range, completely eliminating descent jitter. Simultaneously, because the oil pressure is balanced in advance, the elastic reset element only needs to provide initial sealing preload, significantly reducing the interference of its nonlinear characteristics on the inner valve core's movement. Combined with precise and controllable driving force, the jack's descent speed error can be controlled within the expected design value.

[0028] 2) Utilizing the pressure balance principle, the resistance required to open the inner valve core is significantly reduced, resulting in a substantial decrease in operating force and enhanced ease of use. The pressure balance channel ensures that the oil pressure entering the second oil passage is balanced in advance, so that the inner valve core only needs to overcome the preload of the elastic reset element when opening, thus greatly reducing the operating force.

[0029] 3) This solution features a simple and compact structure, reducing manufacturing costs and improving reliability in harsh environments, making it widely adaptable to various working conditions. Furthermore, the core components of the differential pressure balanced drain valve in this solution consist only of the valve body and valve core assembly, resulting in fewer parts and lower manufacturing costs. The modular design of the sealing body and pressure balancing channel facilitates maintenance and replacement, and the compact oil circuit layout significantly reduces axial dimensions. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a three-dimensional schematic diagram of the electric pump station disclosed in this utility model.

[0032] Figure 2 This is a three-dimensional schematic diagram of the oil pump disclosed in this utility model from one perspective (with hidden lines visible).

[0033] Figure 3 This is a three-dimensional schematic diagram of the oil pump disclosed in this utility model from another perspective (with hidden lines visible).

[0034] Figure 4 yes Figure 2 Top view (with driver components hidden).

[0035] Figure 5 This is a schematic diagram of the differential pressure balanced drain valve disclosed in this utility model (i.e.) Figure 4 (AA sectional view).

[0036] Figure 6 This is also a schematic diagram of the differential pressure balanced drain valve disclosed in this utility model (i.e.) Figure 6 yes Figure 5 (BB cross-sectional view).

[0037] Figure 7 yes Figure 6 A magnified view of part of I.

[0038] Figure 8 This is a three-dimensional schematic diagram of the inner valve core in the differential pressure balanced oil drain valve disclosed in this utility model (with the hidden lines visible).

[0039] 1-Motor; 2-Oil pump; 21-Pump body; 211-First oil passage; 212-Second oil passage; 22-Control valve group; 221-Functional valve unit; 2211-Differential pressure balanced drain valve; 22111-Valve core assembly; 221111-Inner valve core; 2211111-Pressure balance channel; 221112-Compression spring; 22112-Pressure balance mechanism; 221121-Pushing component; 221122-Sealing body; 22113-Drive assembly; 221131-Electromagnetic drive unit; 221132-Linkage rod; 3-Oil tank; 4-Hydraulic cylinder. Detailed Implementation

[0040] The electric pump station is the core power and control hub of the electric hydraulic horizontal jack, providing stable and powerful power output for its lifting and lowering operations.

[0041] like Figure 1 As shown, the electric pump station mainly consists of several parts, including a motor 1, an oil pump 2, an oil tank 3, and a hydraulic cylinder 4. The oil pump 2 is the core power component and energy conversion hub of the electric pump station, providing hydraulic energy to the electric hydraulic horizontal jack. The electric pump station uses the oil pump 2 as its installation core. The motor 1 provides power to the oil pump 2, driving it to pressurize and transport the hydraulic oil in the oil tank 3. This oil is then transmitted through pipelines to the hydraulic cylinder 4, driving the hydraulic cylinder 4 to achieve mechanical action. This completes the conversion from electrical energy to hydraulic energy and then to mechanical energy, realizing power output and execution functions.

[0042] like Figure 2 , 3 As shown, the oil pump 2 includes a pump body 21 and a control valve assembly 22. The control valve assembly 22 is integrated into the pump body 21. As the core control module of the oil pump 2, the control valve assembly 22 achieves precise control of the hydraulic system through integrated and modular design. The control valve assembly 22 is based on the pump body 21 to construct a first oil passage 211 and a second oil passage 212, and the parallel functional valve units 221 can independently adjust the pressure, flow rate and flow direction of each oil passage. In particular, the integrated differential pressure balance type drain valve 2211 effectively reduces flow fluctuations and pressure shocks when the jack is lowered, ensuring the smooth operation of the hydraulic system.

[0043] like Figures 4-6 As shown, the differential pressure balanced drain valve 2211 mainly consists of a valve body, a valve core assembly 22111, a pressure balancing mechanism 22112, and a drive assembly 22113. The pump body 21 also serves as the valve body, and the valve core assembly 22111, pressure balancing mechanism 22112, and drive assembly 22113 are directly integrated into the pump body 21, reducing the need for independent valve body structures and significantly simplifying the system architecture.

[0044] The valve core assembly 22111 is located within the valve body (i.e., pump body 21), and includes an axially movable inner valve core 221111 and a compression spring 221112. For example... Figure 8 As shown, the inner valve core 221111 has a through pressure balance channel 2211111. The compression spring 221112 provides a preload force to cause the inner valve core 221111 to block the initial sealing path between the first oil passage 211 and the second oil passage 212.

[0045] The pressure balancing mechanism 22112 includes an axially movable pusher 221121 and a sealing body 221122. In the initial state, the sealing body 221122, under the combined action of the preload of the compression spring 221112 and the hydraulic pressure of the first oil passage 211, seals the pressure balancing channel 2211111. Figure 7 As shown, after the pusher 221121 is inserted into the pressure balance channel 2211111, the two are in a clearance fit, and the clearance value d on one side is controlled between 0.2 and 0.4 mm.

[0046] like Figure 5 , Figure 6 As shown, the sealing body 221122 and the inlet end of the pressure balance channel 2211111 adopt a conical sealing design with a cone angle of 60 to 120°. Combined with a high-precision surface with Ra≤0.4μm, when the sealing body 221122 approaches the inlet of the pressure balance channel 2211111, the conical geometry generates a radial convergent guiding force, which can automatically correct the eccentricity of the sealing body 221122 and ensure that the spherical surface and the conical surface fit together evenly.

[0047] The drive assembly 22113 includes an electromagnetic drive unit 221131 and a linkage rod 221132. The linkage rod 221132 is rigidly connected to the pusher 221121 and forms an axial movement gap with the inner valve core 221111, and the distance of the axial movement gap is greater than the displacement required for the sealing body 221122 to release the seal.

[0048] The working principle of the differential pressure balanced drain valve 2211 is roughly as follows:

[0049] Under normal operating conditions of the electric pump station, the hydraulic oil in the system circulates according to the predetermined working oil circuit to maintain the stable working state of the electric hydraulic horizontal jack. At this time, the compression spring 221112 applies a stable preload to the inner valve core 221111, ensuring a reliable isolation between the first oil passage 211 and the second oil passage 212, preventing abnormal short-circuit backflow of the oil. At the same time, under the combined action of the preload of the compression spring 221112 and the hydraulic oil pressure in the first oil passage 211, the sealing body 221122 tightly seals the inlet of the pressure balance channel 2211111, thereby preventing oil from flowing into the pressure balance channel 2211111 under unnecessary circumstances, ensuring that the pressure distribution and oil flow direction in the system meet the normal operating requirements.

[0050] When the system performs an oil release operation (e.g., in specific working conditions such as when an electro-hydraulic horizontal jack needs to be lowered to release support for a heavy object), the system control signal triggers the electromagnetic drive unit 221131 to start. The electromagnetic drive unit 221131 then generates electromagnetic force, driving the linkage rod 221132 to move axially. Since the linkage rod 221132 and the pusher 221121 are rigidly connected, the pusher 221121 will synchronously generate axial displacement under the drive of the linkage rod 221132. As the pusher 221121 moves, it will gradually approach and eventually push the seal 221122, overcoming the preload of the compression spring 221112 and the hydraulic force of the first oil passage 211, thus releasing the blockage of the pressure balance channel 2211111. Once the pressure balance channel 2211111 is opened, the hydraulic oil with a certain pressure in the first oil passage 211 will quickly flow into the area above the inner valve core 221111 through the pressure balance channel 2211111. Through this process, the pressure difference between the front and rear sides of the inner valve core 221111 is quickly balanced, creating favorable pressure conditions for subsequently opening the main flow path between the first oil passage 211 and the second oil passage 212. After the pressure balance is completed, the electromagnetic drive unit 221131 remains energized, and the linkage rod 221132 continues to push the pusher 221121 forward. At this time, under the combined action of the residual small pressure difference and the pusher 221121, the inner valve core 221111 overcomes the preload of the compression spring 221112 and begins to undergo axial displacement. As the inner valve core 221111 moves, the previously blocked flow path between the first oil passage 211 and the second oil passage 212 is gradually opened, and the flow path gradually expands as the displacement of the inner valve core 221111 increases. Driven by the pressure difference, the hydraulic oil under high pressure in the system rapidly flows back to the oil tank 3 through the connected first oil passage 211 and second oil passage 212, thereby achieving efficient oil discharge and meeting the system's requirements for discharge speed and flow rate.

[0051] It is important to emphasize that during the entire operation, the linkage rod 221132 will only contact the inner valve core 221111 and begin to push the inner valve core 221111 to move after the pusher 221121 has moved to completely release the seal 221122 from blocking the pressure balance passage 2211111. This ensures the sequentiality and stability of the oil draining operation.

[0052] Once the system completes the oil draining operation and the system pressure gradually decreases to a pre-set appropriate range as the oil flows back, the system control signal will de-energize the electromagnetic drive unit 221131. After de-energization, the electromagnetic force generated by the electromagnetic drive unit 221131 disappears, and the linkage rod 221132 immediately releases its axial pushing action on the pusher 221121. At this time, under the strong elastic restoring force of the compression spring 221112, the sealing body 221122 quickly moves towards the inlet of the pressure balance channel 2211111 and re-seales the pressure balance channel 2211111 tightly, preventing the oil from flowing unintended through this channel again. At the same time, the elastic restoring force of the compression spring 221112 will also push the inner valve core 221111 to move in the opposite direction along the axis, so that it returns to the initial blocking position, and re-cuts off the connection between the first oil passage 211 and the second oil passage 212, thereby ensuring that the electric pump station can return to a stable working state after completing the oil discharge operation and continue to provide stable and reliable power support for the electric hydraulic horizontal jack according to the normal working process.

[0053] By adopting the above technical solution, this differential pressure balanced oil discharge valve exhibits the following significant advantages in practical applications:

[0054] 1) During the oil draining process, the linkage rod 221132 pushes the pusher 221121, first opening the pressure balance channel 2211111 of the sealing body 221122, connecting the first oil passage 211 and the second oil passage 212. This stage significantly reduces the pressure difference across the inner valve core 221111 by balancing the system oil pressure. Based on this, when the main flow path is opened, the inner valve core 22111 only needs to overcome a small resistance to achieve axial displacement, avoiding the flow shock caused by sudden pressure changes in traditional drain valves. This keeps the pressure change gradient within a very small range, effectively reducing system vibration and noise levels, and ensuring a smooth and vibration-free jack descent process.

[0055] 2) Through the coordinated operation of the compression spring 221112 and the pressure balance channel 2211111, precise pressure control of the oil discharge process is achieved. During the pressure balance stage, the movement of the sealing body 221122 pre-adjusts the system pressure, creating stable pressure conditions for the main oil discharge stage. During the main oil discharge stage, the inner valve core 221111 overcomes the preload under precise axial driving force, forming a flow path linearly related to the driving force. This design effectively reduces the opening and closing pressure error, improving the pressure control accuracy to within the expected design value.

[0056] It should also be noted that during normal operation, the presence of the pressure balancing channel 2211111 reduces the system back pressure to a certain extent, effectively reducing the load on the electric pump station and lowering system energy consumption. During the operation of the inner valve core 221111, since the oil pressure has already been balanced through the pressure balancing channel, only a small driving force is needed to actuate the inner valve core 221111. This not only improves operational convenience but also significantly extends the service life of the drive components.

[0057] As a further optimization of the above technical solution, such as Figures 4-6 As shown, the minimum cross-sectional area of ​​the flow path formed after the displacement of the inner valve core 221111 is preferably 8 to 10 times the cross-sectional area of ​​the pressure balance channel 2211111. This design achieves high efficiency and stability in the oil discharge process through a differentiated flow area layout: on the one hand, the pressure balance channel 2211111 is preferentially opened with a smaller cross-sectional area, which can quickly balance the oil pressure before and after the inner valve core 221111 at the moment of opening, significantly reducing the resistance when the main channel is opened subsequently; on the other hand, the main flow path is opened with a larger cross-sectional area, which can fully meet the needs of rapid hydraulic oil return, and use the large flow capacity to ensure that the high-pressure oil is quickly discharged when the jack is lowered, avoiding oil discharge delay caused by throttling effect and improving operating efficiency.

[0058] Finally, it should be noted that, to ensure the orderly and stable oil draining process, the parameters of key components in this design have been optimized: the diameter of the pressure balance channel 2211111 is preferably 1-3mm, and the diameter of the sealing body 221122 is 2-5 times the diameter of the pressure balance channel 2211111. Simultaneously, the preload of the compression spring 221112 is controlled between 50-300N. This effectively ensures that when the hydraulic jack needs to perform an oil draining operation, the pressure balance channel 2211111 opens before the inner valve core 221111, achieving a gradual oil draining process of "balancing oil pressure first, then opening the main channel." This effectively avoids the impact vibration of the inner valve core 221111 caused by a sudden drop in pressure, making the jack descent process smoother and more stable, further improving the reliability and operational safety of the equipment.

[0059] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pressure differential balanced oil drain valve characterized by, include: The valve body has a first oil passage and a second oil passage formed inside. A valve core assembly, disposed within the valve body, includes an axially movable inner valve core and an elastic reset element; the inner valve core is provided with a through pressure balance channel; the elastic reset element provides a preload force to cause the inner valve core to block the initial sealing path between the first oil passage and the second oil passage; The pressure balancing mechanism includes an axially movable pusher and a sealing body; in the initial state, the sealing body blocks the pressure balancing channel under the combined action of the pre-tightening force of the elastic reset element and the hydraulic pressure of the first oil passage. A drive assembly configured to sequentially transmit axial driving force toward the seal and the inner valve core; The action process of the driving component triggers the following actions in sequence: First stage: The drive component pushes the pusher, causing the seal to release the blockage of the pressure balance channel, and the first oil passage and the second oil passage are connected through the pressure balance channel to achieve oil pressure balance; Second stage: The drive component continues to operate and acts directly on the inner valve core, which overcomes the preload and moves axially. The first oil passage and the second oil passage are connected through the flow path formed after the inner valve core moves, so as to realize the controllable return of hydraulic oil.

2. The differential pressure balanced oil drain valve of claim 1, wherein, Only when the pusher moves to completely release the seal from blocking the pressure balance channel can the drive assembly contact the inner valve core and push it to move.

3. The differential pressure balanced oil drain valve of claim 2, wherein, The drive assembly includes a power output section and a linkage rod; the linkage rod is rigidly connected to the pusher and forms an axial movement gap with the inner valve core, and the distance of the axial movement gap is greater than the displacement required for the sealing body to release the seal.

4. The differential pressure balanced oil drain valve of claim 3, wherein, The linkage rod and the pusher are integrally formed or connected by threads.

5. The differential pressure balanced oil drain valve of claim 3, wherein, The power output unit is at least one of an electromagnetic drive unit, a hydraulic drive unit, or a manual operation unit.

6. The differential pressure balanced oil drain valve of claim 1, wherein, The minimum cross-sectional area of ​​the flow path formed after the inner valve core is displaced is 8 to 10 times the cross-sectional area of ​​the pressure balance channel, so as to achieve oil pressure balance first and then large flow return.

7. The pressure differential balanced oil drain valve of claim 1, wherein The diameter of the pressure balancing channel is 1 to 3 mm; the diameter of the sealing body is 2 to 5 times the diameter of the pressure balancing channel; and the elastic reset element is a compression spring with a preload of 50 to 300 N.

8. The differential pressure balanced drain valve according to any one of claims 1-7, characterized in that, The sealing body forms a conical seal with the inlet end of the pressure balance channel, and the cone angle α is 60 to 120°, with a surface roughness Ra ≤ 0.4 μm.

9. A control valve group characterized by include: The valve block has a first and a second main oil passage inside. At least two functional valve units are arranged in parallel within the valve block; At least one of the aforementioned functional valve units is a differential pressure balanced drain valve as described in any one of claims 1-8; Both the first master oil passage and the second master oil passage are connected to the corresponding interface of the functional valve unit to form independent and parallel controllable multi-channel working oil passages.

10. An electric pump station comprising a motor, an oil pump, an oil tank and a hydraulic cylinder; the motor drives the oil pump to operate, and pressurized hydraulic oil in the oil tank is delivered into the hydraulic cylinder, characterized in that, The oil pump includes a pump body and a control valve assembly as described in claim 9; the control valve assembly is integrated into the pump body and is used to control the hydraulic cylinder pressure oil to flow back to the oil tank sequentially through the first oil passage and the second oil passage during the jack descent process.

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