Manual hydraulic pump

Abstract

The invention discloses a manual hydraulic pump, and relates to the technical field of hydraulic pumps, the manual hydraulic pump comprises an oil tank and a pump body communicated with the oil tank, an oil suction hole is formed in the pump body, the oil suction hole is communicated with the oil tank, and a high-pressure oil suction valve and a low-pressure oil suction valve are coaxially arranged in the oil suction hole; the piston cavity comprises a high-pressure piston cavity and a low-pressure piston cavity which are coaxially arranged, the high-pressure piston cavity is communicated with the high-pressure oil suction valve, and the low-pressure piston cavity is communicated with the low-pressure oil suction valve; an oil outlet one-way valve is installed in the oil discharge hole, and the oil discharge hole is used for receiving oil from the high-pressure piston cavity and the low-pressure piston cavity and outputting pressure oil to an executing mechanism; a high-pressure oil suction valve and a low-pressure oil suction valve which are coaxially arranged are arranged in the pump body and correspondingly connected with a high-pressure piston cavity and a low-pressure piston cavity which are coaxially arranged, and oil is discharged through an oil discharge hole; the two-way system is integrated in one pump body, so that compared with external double pumps or valve banks, external pipelines are greatly simplified, the overall size and weight are reduced, and portability and reliability are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic pumps, and more particularly to a hand-operated hydraulic pump. BACKGROUND

[0002] As a common portable power source, the hand-operated hydraulic pump is widely used in equipment maintenance, rescue jacking, engineering testing and other occasions, which converts mechanical energy into hydraulic energy through human power. The traditional hand-operated hydraulic pump usually includes basic components such as an oil tank, a pump body, a piston and a control lever. The reciprocating movement of the piston in the pump body forms a negative pressure, and the hydraulic oil is sucked from the oil tank and then discharged to the actuator through pressure boosting.

[0003] However, the hand-operated hydraulic pump in the prior art has some obvious technical problems in design and use: Firstly, most pump bodies adopt a single piston cavity and oil suction channel structure, so that the output pressure and flow characteristics of the pump are relatively fixed. When the actuator needs a large flow to achieve rapid action in the no-load or low-pressure stage, and needs a high pressure to overcome the load in the high-pressure stage, such single-mode pump cannot adapt efficiently, and often needs to realize working condition switching through a complex bypass or additional control valve, resulting in complex system structure, cumbersome operation and reduced reliability.

[0004] Secondly, in order to realize the functions of oil suction and oil discharge, multiple oil passage holes are needed to be machined in the pump body, and the traditional oil passage layout often makes the machining process complex, for example, multiple holes need to be drilled from different directions and their accurate intersection needs to be ensured, which increases the manufacturing cost and the risk of sealing failure. In addition, in the case of pressure regulation or safety protection, the related valve parts are usually arranged dispersedly or externally, which not only increases the overall volume of the pump, but also makes the internal flow passage circuitous, increases the pressure loss and slows down the response speed.

[0005] Therefore, how to provide a hand-operated hydraulic pump with more compact structure, higher integration and convenient switching between high and low pressure output modes is a problem to be solved by those skilled in the art. SUMMARY

[0006] Therefore, the present application provides a hand-operated hydraulic pump, which aims to solve the technical problems of complex structure and / or only single working mode.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: A hand-operated hydraulic pump includes an oil tank and a pump body in communication with the oil tank, and the pump body is internally provided with: An oil suction hole, which is in communication with the oil tank and has a high-pressure oil suction valve and a low-pressure oil suction valve coaxially arranged inside; A piston cavity comprising coaxially arranged high-pressure piston cavity and low-pressure piston cavity, the high-pressure piston cavity is communicated with the high-pressure oil suction valve, and the low-pressure piston cavity is communicated with the low-pressure oil suction valve; An oil discharge hole internally provided with an oil outlet check valve, used for receiving oil from the high-pressure piston cavity and the low-pressure piston cavity and outputting pressure oil to the actuator.

[0008] Through the above technical scheme, the application provides a kind of manual hydraulic pump, pump body is equipped with coaxially arranged high-pressure oil suction valve and low-pressure oil suction valve, and correspondingly connect coaxially arranged high-pressure piston cavity and low-pressure piston cavity, finally by one oil discharge hole is discharged;Low-pressure oil suction valve is matched with low-pressure piston cavity, can provide large flow output in the piston stroke, realize the quick idle action of actuator;High-pressure oil suction valve is matched with high-pressure piston cavity, can output small flow, high pressure when needed, to overcome large load;System can automatically switch mode according to load pressure, without manual intervention, significantly improve the operation convenience and work efficiency;Double-path system is completely integrated in one pump body, compared with the scheme of external double pump or valve group, greatly simplify external pipeline, reduce overall volume and weight, improve portability and reliability;Share one oil discharge port: high and low pressure oil finally converges into the same oil discharge hole output, so that actuator interface is unified, simplify the connection with driven equipment.

[0009] Preferably, in the above-mentioned manual hydraulic pump, a first process hole parallel to the oil suction hole is arranged on the pump body, and the first process hole is communicated with the low-pressure piston cavity through a first inclined hole arranged inside the pump body. A specific oil passage is provided to ensure the oil suction function of the low-pressure piston cavity. The combination of process hole and inclined hole solves the problem of deep hole and cross hole machining, enabling the internal transverse oil passage that is originally difficult to drill directly to be realized, improving the manufacturability of the pump body. Reasonable hole design helps to reduce oil flow resistance and improve oil suction efficiency in low-pressure mode.

[0010] Preferably, in the above-mentioned manual hydraulic pump, a second process hole perpendicular to the first process hole and the oil suction hole is arranged in the pump body, and the second process hole is vertically arranged in the first process hole and the oil suction hole. The arrangement of the second process hole provides a key interface for connecting the oil suction source and the low-pressure oil suction path, and together with the first process hole and the first inclined hole, it constitutes a complete low-pressure oil suction channel.

[0011] Preferably, in the above-mentioned manual hydraulic pump, it further comprises low-pressure adjusting hole and high-pressure adjusting hole arranged side by side in the pump body, and adjusting valves are arranged in the low-pressure adjusting hole and the high-pressure adjusting hole. The parallel arrangement of high and low pressure adjusting holes with adjusting valves allows users to set the upper limit of high and low pressure of the system respectively, so that the pump can flexibly adapt to actuators in different working conditions, expanding the product versatility.

[0012] Preferably, in the above-mentioned manual hydraulic pump, a low-pressure overflow hole and a high-pressure overflow hole are formed in the pump body, the low-pressure overflow hole is in communication with the low-pressure adjusting hole and the oil tank respectively, and the high-pressure overflow hole is in communication with the high-pressure adjusting hole and the oil tank respectively. A closed and efficient overflow oil return channel is formed in the pump body, which ensures that the overload oil can quickly and smoothly return to the oil tank, maintains the stability of the system pressure and assists heat dissipation.

[0013] Preferably, in the above-mentioned manual hydraulic pump, a third process hole vertically communicating with the oil discharge hole is formed in the pump body, and a pressure sensing oil path communicating with the third process hole is formed in the pump body, the pressure sensing oil path vertically communicates with the low-pressure adjusting hole. Through the third process hole and the pressure sensing oil path, a pressure feedback channel is established between the oil discharge hole and the low-pressure adjusting hole.

[0014] Preferably, in the above-mentioned manual hydraulic pump, a pressure relief oil path coaxial with the low-pressure adjusting hole is formed in the pump body, a sealing element is movably arranged coaxially in the pressure relief oil path, the sealing element can move axially along the pressure relief oil path to block and release the oil inlet of the low-pressure adjusting hole. The sealing element is essentially a spool or valve core driven by pilot pressure. The working principle is as follows: normal low-pressure stage: the system pressure from the pressure sensing oil path is low, the force acting on one end of the sealing element is insufficient to overcome the spring pre-tightening force (if any) and other resistances, the sealing element remains in place, blocking the oil inlet of the low-pressure adjusting hole, and the low-pressure piston cavity works normally; when the switching pressure is reached: when the system pressure (i.e. output pressure) rises to the set value, the hydraulic pressure transmitted to one end of the sealing element through the pressure sensing oil path increases, which pushes the sealing element to move axially automatically, thereby releasing the blockage of the oil inlet of the low-pressure adjusting hole. Automatic unloading and mode switching of the low-pressure circuit: once the sealing element is pushed to move by pressure, the overflow or unloading channel of the low-pressure piston cavity (through the low-pressure adjusting hole) is opened; this will cause the pressure built in the low-pressure piston cavity to be unloaded, so that it stops effective output, and the system automatically and smoothly switches to the high-pressure working mode which is fully supplied by the high-pressure piston cavity; in the high-pressure mode, if the pressure abnormally rises beyond the high-pressure set value, the high-pressure overflow valve will act alone.

[0015] Preferably, in the above-mentioned manual hydraulic pump, the oil suction hole is divided into a high-pressure oil suction hole and a low-pressure oil suction hole which are in communication in sequence, and the oil inlet of the high-pressure adjusting hole is in communication with the high-pressure oil suction hole. The oil suction sources and control feedback points of the high-pressure and low-pressure systems are physically separated from the structure, which prevents the pressure interference of the two sets of circuits at the source, ensures the accuracy of the sensing and control of the high-pressure overflow valve, and improves the working independence and stability of the dual-circuit system.

[0016] Preferably, in the aforementioned manual hydraulic pump, the pump body has a second oblique hole communicating with the third process hole, and a pressure gauge is installed in the second oblique hole. This seamless integration of pressure visualization into the pump body allows the operator to monitor the system status in real time, facilitating precise operation, fault diagnosis, and pressure setting, significantly improving operational safety and professionalism.

[0017] Preferably, in the aforementioned manual hydraulic pump, the pump body is further provided with a return oil hole communicating with the oil tank; a return oil valve is installed at the return oil hole. Through the dedicated return oil hole and return oil valve, a direct oil return channel is provided for retraction after work is completed. Under its own weight or the action of the actuator's built-in spring, the oil can flow smoothly and at low pressure back to the oil tank, allowing the operator to effortlessly retract the tool, greatly improving operational convenience and work efficiency.

[0018] Preferably, the aforementioned manual hydraulic pump further includes a pressure rod hinged to the pump body, on which a piston is fixed, and the piston extends coaxially into the piston chamber. This combination of a labor-saving lever mechanism and a coaxial piston structure that ensures sealing achieves basic pumping functionality while ensuring driving efficiency and long-term sealing reliability.

[0019] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a manual hydraulic pump, which has the following beneficial effects: This invention integrates two independent suction and discharge systems for high pressure and low pressure within a coaxial pump body, and innovatively designs an automatic control oil circuit based on output pressure sensing. This enables the pump to achieve fully automatic and seamless switching between low-pressure and high-pressure modes according to load changes; no manual valve operation is required, greatly improving operating efficiency and ease of use. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 The attached figure is a schematic diagram of the structure of the manual hydraulic pump provided by the present invention; Figure 2 The attached figure is a cross-sectional view of the manual hydraulic pump provided by the present invention; Figure 3 The attached figure is an isometric view of the pump body provided by the present invention; Figure 4 The attached figure is a cross-sectional view of the pump body provided by the present invention; Figure 5 The attached figure is a cross-sectional view of the pump body provided by the present invention; Figure 6 The attached figure is a cross-sectional view of the pump body provided by the present invention; Figure 7 The attached figure is a cross-sectional view of the pump body provided by the present invention; Figure 8 The attached figure is a cross-sectional view of the pump body provided by the present invention; Figure 9 The attached figure is a schematic diagram of the manual hydraulic pump provided by the present invention from another angle; Figure 10 The attached image is... Figure 9 sectional view of attached figure aa; Figure 11 The attached image is... Figure 10 Enlarged view of section A in the attached figure; Figure 12 The attached figure is a cross-sectional view of the manual hydraulic pump provided by the present invention; Figure 13 The attached figure is an isometric view of the pump body provided by the present invention without the pressure sensing oil circuit; Figure 14 The attached figure is a cross-sectional view of the pump body provided by the present invention with the pressure relief oil passage removed.

[0022] Wherein: 1-oil tank; 2-pump body; 201-oil suction hole; 202-high pressure oil suction valve; 2021-first spring; 2022-first steel ball; 2023-high pressure valve core; 203-low pressure oil suction valve; 2031-second spring; 2032-second steel ball; 2033-low pressure valve core; 204-high pressure piston chamber; 205-low pressure piston chamber; 206-oil discharge hole; 207-oil outlet check valve; 2071-fifth steel ball; 2072-fifth spring; 208-first process hole; 209-first oblique hole; 210-second process hole; 211-low pressure regulating hole; 212-high pressure regulating hole; 213-regulating valve; 21 31-Third steel ball; 2132-Third spring; 2133-Locking nut; 214-Low pressure overflow hole; 215-High pressure overflow hole; 216-Third process hole; 217-Pressure sensing oil circuit; 218-Pressure relief oil circuit; 219-Seal; 2191-Valve stem; 2192-Sealing ring; 220-Second oblique hole; 221-Return oil hole; 222-Valve cavity; 3-Pressure gauge; 4-Return oil valve; 41-Valve seat; 42-Elastic seal; 421-Fourth steel ball; 422-Fourth spring; 43-Valve core; 44-Adjusting rod; 45-Return oil gap; 46-Limit screw; 47-Handwheel; 5-Pressure rod; 51-Piston. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: See appendix Figure 1 As shown, an embodiment of the present invention discloses a manual hydraulic pump, including an oil tank 1 and a pump body 2 communicating with the oil tank 1, characterized in that the pump body 2 has the following openings: Oil suction port 201 is connected to oil tank 1, and a high-pressure oil suction valve 202 and a low-pressure oil suction valve 203 are coaxially arranged inside it; a filter valve is provided at the connection between oil suction port 201 and oil tank 1.

[0025] The piston chamber includes a high-pressure piston chamber 204 and a low-pressure piston chamber 205 arranged coaxially. The high-pressure piston chamber 204 is connected to the high-pressure oil suction valve 202, and the low-pressure piston chamber 205 is connected to the low-pressure oil suction valve 203. The drain hole 206 has an oil outlet check valve 207 installed inside it, which is used to receive oil from the high-pressure piston chamber 204 and the low-pressure piston chamber 205, and output pressurized oil to the actuator.

[0026] Specifically, the high-pressure suction valve 202 includes a first spring 2021, a first steel ball 2022, and a high-pressure valve core 2023 arranged coaxially inside the suction hole 201; the low-pressure suction valve 203 includes a second spring 2031, a second steel ball 2032, and a low-pressure valve core 2033 arranged coaxially inside the suction hole 201; the oil outlet check valve 207 includes a fifth steel ball 2071 and a fifth spring 2072. Furthermore, the oil outlet check valve 207 also includes a through-hole screw 2073, installed inside the oil drain hole 206, to hold the fifth spring 2072 in place, to prevent the fifth spring 2072 and the fifth steel ball 2071 from falling out when replacing the quick connector connected to the oil pipe.

[0027] In some specific embodiments, as shown in the appendix Figure 3 and attached Figure 4 As shown, the pump body 2 has a first process hole 208 arranged parallel to the oil suction hole 201. The first process hole 208 is connected to the low-pressure piston chamber 205 through a first oblique hole 209 opened inside the pump body 2.

[0028] More specifically, as shown in the appendix Figure 4 and attached Figure 8As shown, a second process hole 210 is provided in the pump body 2, which is perpendicular to the first process hole 208 and the oil suction hole 201. The second process hole 210 is perpendicularly inserted into the first process hole 208 and the oil suction hole 201.

[0029] In other embodiments, as shown in the appendix Figure 3 Appendix Figure 5 Appendix Figure 6 As shown, it also includes a low-pressure regulating hole 211 and a high-pressure regulating hole 212 that are opened side by side in the pump body 2. A regulating valve 213 is installed in both the low-pressure regulating hole 211 and the high-pressure regulating hole 212. An oil sealing cap (not shown in the figure) is installed at the low-pressure regulating hole 213 and the high-pressure regulating hole 214 to prevent oil leakage during operation.

[0030] like Figures 5-6 As shown, the regulating valve 213 includes a third steel ball 2131, a third spring 2132, and a locking nut 2133, which are respectively installed inside the low-pressure regulating port 211 and the high-pressure regulating port 212. The locking nut 2133 can adjust the compression of the third spring 2132 as needed, thereby adjusting the pressure setting value.

[0031] In specific embodiments, as shown in the appendix Figures 4-6 As shown, the pump body 2 has a low-pressure overflow hole 214 and a high-pressure overflow hole 215 inside. The low-pressure overflow hole 214 is connected to the low-pressure regulating hole 211 and the oil tank 1 respectively; the high-pressure overflow hole 215 is connected to the high-pressure regulating hole 212 and the oil tank 1 respectively.

[0032] In a specific example, as shown in the appendix Figure 4 and attached Figure 7 As shown, the pump body 2 has a third process hole 216 that is vertically connected to the oil drain hole 206, and a pressure sensing oil passage 217 that is connected to the third process hole 216. The pressure sensing oil passage 217 is vertically connected to the low pressure regulating hole 211.

[0033] More specifically, the pump body 2 is provided with a pressure relief oil passage 218 coaxial with the low pressure regulating hole 211. A sealing element 219 is coaxially movable inside the pressure relief oil passage 218. The sealing element 219 can move axially along the pressure relief oil passage 218 to block and release the oil inlet of the low pressure regulating hole 211.

[0034] like Figure 5 As shown, the sealing element 219 includes a valve stem 2191 and a sealing ring 2192 sleeved on the outside of the valve stem 2191; when the pressure in the pressure sensing oil circuit 218 reaches the set value, it pushes the valve stem 2191 to rise, pressing against the third steel ball 2131 and compressing the third spring 2132 to achieve pressure unloading.

[0035] It should be noted that the stem of valve 2191 can also be designed with a tapered structure to achieve a seal, or a steel ball can be used to achieve a seal.

[0036] In some specific examples, the oil suction port is divided into a high-pressure oil suction port and a low-pressure oil suction port that are connected in sequence. The oil inlet of the high-pressure regulating port is connected to the high-pressure oil suction port, and the oil inlet of the low-pressure regulating port is connected to the low-pressure oil suction port.

[0037] In some other embodiments, the pump body 2 has a second oblique hole 220 that communicates with the third process hole 216, and a pressure gauge 3 is installed in the second oblique hole 220.

[0038] In a specific example, it also includes a pressure rod 5 hinged to the pump body 2, on which a piston 51 is fixed, and the piston 51 extends coaxially into the piston chamber.

[0039] More specifically, plugs and seals / gaskets are installed at the process holes and corresponding positions on the pump body 2, and hard or soft seals are installed at the corresponding positions of the external contact parts.

[0040] In a specific embodiment, the pump body 2 is also provided with an oil return hole 221 that communicates with the oil tank 1; an oil return valve 4 is installed at the oil return hole 221.

[0041] As attached Figures 9-12 As shown, a valve chamber 222 is provided on the pump body 2, and a return oil valve 4 is installed in the valve chamber 222. The return oil valve 4 includes: Valve seat 41 is detachably connected to the opening of valve chamber 222; The elastic seal 42 is axially movable and arranged within the valve cavity 222; The valve core 43 is fixed in the valve cavity 222 and located between the valve seat 41 and the elastic seal 42. The valve core 43 has a through hole 431 along its axial direction, and the elastic seal 42 abuts against the through hole to form a seal. Adjusting rod 44 is threaded inside valve seat 41 and can extend into valve core 43. An oil return gap 45 is formed between adjusting rod 44 and valve core 43. When adjusting rod 44 is turned, its end can pass through through hole 431 and press against elastic seal 42, so that elastic seal 42 disengages from through hole 431, thereby opening the oil return passage connecting valve chamber 222 and oil tank 1.

[0042] In some specific examples, one end of the valve seat 41 is threaded into the valve cavity 222, and the other end is located outside the pump body 2.

[0043] In some other embodiments, a limiting screw 46 for limiting the adjusting rod 44 is installed on the valve seat 41 located on the outside of the pump body 2. A limiting groove is formed on the rod body of the adjusting rod located on the outside of the pump body, and the end of the limiting screw extends into the limiting groove. This structure can effectively prevent the adjusting rod from being over-tightened or prevent the adjusting rod from being unscrewed and falling off.

[0044] In addition to the limit screw 46, the limit can also be achieved by a through-hole nut that is threaded onto the outside of the adjusting rod 44, with the nut positioned between the valve seat 41 and the handwheel 47.

[0045] In a specific embodiment, the elastic seal 42 includes a fourth steel ball 421 and a fourth spring 422 abutting against the through hole 431. One end of the fourth spring 422 abuts against the inner wall of the valve cavity 222, and the other end abuts against the fourth steel ball 421.

[0046] In a specific example, valve core 43 is threaded into valve cavity 222.

[0047] In some examples, a handwheel 47 is fixed to the end of the adjusting rod 44 away from the valve core 43. Furthermore, the handwheel 47 can also be replaced by a handle, through which the adjusting rod 44 can be moved forward and backward.

[0048] More specifically, the adjusting rod 44 includes a first rod segment 441 and a second rod segment 442 with different outer diameters. The first rod segment 441 is threaded to the valve seat 41, and the second rod segment 442 can extend into the valve core 43, and its outer diameter is smaller than the inner diameter of the through hole 431 to form an oil return gap 45. The oil return hole 221 is connected to the oil return gap 45.

[0049] The working principle of return valve 4 is as follows: Normally closed state (sealed): In the non-return oil state, under the action of the elastic force of the fourth spring 422 and the oil pressure, the fourth steel ball 421 is pushed to press tightly against the end face of the through hole 431 of the valve core 43, forming a seal and blocking the oil passage; the adjusting rod 44 is in the unscrewed position, and its end does not contact or only slightly contacts the fourth steel ball 421, which does not affect the seal.

[0050] Start the return oil flow (manual operation): When oil return is required, the operator rotates the handwheel 47, turning the adjusting rod 44 inwards into the valve; the second section 442 of the adjusting rod 44 is pushed forward, directly pressing against the fourth steel ball 421. The axial force overcomes the elastic force of the fourth spring 422 and the oil pressure, pushing the fourth steel ball 421 away from the end face of the through hole 431 of the valve core 43, forming a gap; the oil flows through the gap between the fourth steel ball 421 and the through hole 431, the oil return gap 45, and flows back to the oil tank 1 through the oil return hole 221.

[0051] Shut off return oil (reset): After the oil return is completed, rotate the handwheel 47 in the opposite direction to turn the adjusting rod 44 outward; the pressure on the fourth steel ball 421 at the end of the adjusting rod 44 is released; the fourth spring 422 pushes the fourth steel ball 421 to reset, re-seals the through hole 431, and the oil circuit is cut off.

[0052] The embodiments of the present invention are as follows: The working principle of this manual hydraulic pump is based on its highly integrated dual-channel pumping system and pressure feedback automatic control mechanism. Its core function is to achieve automatic and smooth switching between high and low pressure modes based on the output load pressure.

[0053] 1. Oil suction process (pressure rod lifting stage): The operator lifts the pressure rod 5 upwards, causing the piston 51 fixed thereto to exit from the pump body 2. The volume of the high-pressure piston chamber 204 and the low-pressure piston chamber 205 increases simultaneously, generating a negative pressure for oil suction.

[0054] Low-pressure circuit oil suction: Hydraulic oil in tank 1 is sucked in through suction hole 201. Since the second process hole 210 is vertically inserted between suction hole 201 and first process hole 208, the oil can enter the second process hole 210 from suction hole 201 and flow into the first process hole 208 connected to it. Subsequently, the oil reaches the bottom of low-pressure piston chamber 205 through first inclined hole 209, completing low-pressure oil suction. Under low-pressure conditions, all oil before reaching the low-pressure set value is simultaneously combined and output through high-pressure suction valve 202 and discharged by oil outlet check valve 207.

[0055] High-pressure circuit oil suction: At the same time, the oil directly pushes open the high-pressure oil suction valve 202 from the oil suction hole 201 and enters the high-pressure piston chamber 204; at this stage, the oil outlet check valve 207 is closed to prevent oil backflow.

[0056] The oil outlet check valve 207 remains normally closed when it does not receive oil driving force.

[0057] 2. Low-pressure operation and oil discharge stage (initial pressure of the lever, rapid action of the actuator): The operator presses down the lever 5, and the piston 51 pushes the oil in the two piston chambers.

[0058] The oil pressure in the low-pressure piston chamber 205 rises, closing the low-pressure oil suction valve 203 and opening the oil outlet check valve 207 in the oil drain hole 206 to output to the actuator and drive it to move rapidly.

[0059] At this time, the system output pressure is low. This pressure is transmitted through the drain hole 206, the third process hole 216, and the pressure sensing oil passage 217, acting on one end (e.g., its lower end) of the seal 219 in the pressure relief oil passage 218. This pressure is insufficient to overcome the preset resistance (such as spring force) at the other end of the seal 219, so the seal 219 remains in the blocking position against the oil inlet of the low-pressure regulating hole 211. The low-pressure oil passage is thus able to build up pressure and output normally.

[0060] The oil in the high-pressure piston chamber 204 is also forced out at the same time, and the oil flows out through the same drain hole 206 to provide initial power.

[0061] Pressure sensing and automatic switching phase (load increases, pressure reaches set value): When the actuator contacts the load, the system output pressure continues to rise; when the pressure rises to the preset value of the low-pressure regulating valve 213, the hydraulic pressure transmitted to the seal 219 through the pressure sensing oil circuit 217 increases, which is sufficient to drive it to move automatically axially (e.g., upward).

[0062] The movement of seal 219 presses against the third steel ball 2131, compressing the third spring 2132 and releasing the blockage on the oil inlet of the low-pressure regulating hole 211. At this time, the oil passage of the low-pressure piston chamber 205 is connected to the low-pressure overflow hole 214 through the open low-pressure regulating hole 211, allowing the oil to be depressurized and flow back to the oil tank 1. The low-pressure circuit is thus automatically unloaded, ceasing effective output.

[0063] 4. High-pressure working stage (the pressure bar continues to press down to overcome the large load): After the low-voltage circuit is unloaded, the system automatically switches to pure high-voltage mode, making it easier for users to operate.

[0064] The operator continues to press down the lever 5, and only the high-pressure piston chamber 204 continues to work, outputting a small flow of high-pressure oil, all of which is output through the drain hole 206 to overcome the large working load.

[0065] The maximum system pressure is limited by the high-pressure regulating valve 212. If the pressure abnormally exceeds its set value, the oil will overflow back to the oil tank 1 through the high-pressure regulating port 212 and the high-pressure overflow port 215 to achieve safety protection.

[0066] 5. Oil return function (actuator reset): When the actuator (such as a hydraulic cylinder) needs to retract, the return valve 4 is operated. The oil in the rodless chamber of the actuator flows directly back to the oil tank 1 at low pressure through the return port 221 under its own weight or the action of an internal spring. This circuit is independent of the main pumping system, avoiding contamination of the main oil circuit.

[0067] 6. Pressure monitoring: Throughout the entire operation, the system output pressure is always transmitted to the pressure gauge 3 through the third process hole 216 and the second inclined hole 220, enabling real-time visual monitoring of the working status.

[0068] In summary, this invention, through its unique oil circuit integration and automatic control design, enables the manual hydraulic pump to intelligently respond to load changes and achieve automatic and seamless switching between high and low pressure modes. While ensuring a compact structure and simple operation, it significantly improves work efficiency and power adaptability.

[0069] Example 2: The main difference between this embodiment and Embodiment 1 is that: Figure 13 and Figure 14 As shown, the automatic control components such as the pressure sensing oil circuit 217, the pressure relief oil circuit 218, and the seal 219 have been removed. In this embodiment, the high and low pressure dual piston chambers always operate simultaneously under piston drive. This structure does not have the function of automatically cutting off the low-pressure circuit based on the output pressure; its mode switching relies on the passive response of the system pressure generated by external load changes and the preset overflow threshold. Low-pressure stage: Dual chambers output simultaneously, providing a large flow rate.

[0070] High-pressure stage: When the system pressure rises to the set value of the low-pressure regulating valve, the valve opens to overflow, and the oil output from the low-pressure piston chamber flows back to the oil tank. However, back pressure will still be generated in the chamber during the reciprocating motion of the piston. At this time, the operator needs to continuously apply greater operating force to overcome the additional resistance brought by the low-pressure chamber and push the high-pressure piston chamber to output high-pressure, low-flow oil.

[0071] Mode transition: The transition of the entire system from high flow rate to high pressure is passive and continuous, relying on the operator to perceive and adapt to changes in resistance, rather than being automatically and hard-switched by the internal control mechanism.

[0072] The technical effects that this embodiment can achieve are: By eliminating the sophisticated pressure sensing and relief components, the machining complexity of the pump's internal oil circuitry and the high precision requirements for the coaxiality of deep holes and intersecting holes are greatly reduced, thus decreasing the number of parts and potential leakage points. This not only significantly reduces manufacturing costs but also improves the overall reliability and durability of the system due to its simple structure, making it easier to maintain.

[0073] Despite the different switching methods, the coaxial integrated dual-piston chamber structure is retained. Compared with traditional manual pumps with a single working mode, it can still better adapt to typical operating cycles of low-pressure rapid no-load and high-pressure overcoming load, and has inherent advantages in power adaptability.

[0074] It is suitable for applications with relatively gradual load changes, insensitivity to operating speed, or where strict cost control is required. It offers a compact, robust, and more economical option where users can accept and adapt to changes in pressure through physical exertion.

[0075] It should be noted that the dimensions of each channel and the location of each component involved in this invention can be determined according to actual needs, and are not limited to the positions shown in the accompanying drawings, all of which are within the protection scope of this invention; (See attached drawings for details). Figure 3 For example, as shown in the diagram, the low-pressure regulating port 211 and the high-pressure regulating port 212 are located on the right side of the piston 51. The positions of the low-pressure regulating port 211 and the high-pressure regulating port 212 can be placed on the left side of the piston 51. Another example... Figure 9 As shown, the return valve 4 is located on the front side of the pump body 2, or it can be installed on the rear side of the pump body 2 as needed.

[0076] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. Content not described or recorded in detail is prior art and will not be elaborated upon here.

[0077] The above description of the disclosed embodiments enables those skilled in the art to make or use the 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 invention. Therefore, the 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 hand-operated hydraulic pump comprising an oil tank (1) and a pump body (2) communicating with said oil tank (1), characterized in that, The pump body (2) is provided with: An oil suction hole (201) which communicates with the oil tank (1) and has a high-pressure oil suction valve (202) and a low-pressure oil suction valve (203) coaxially arranged inside; A piston cavity which includes a high-pressure piston cavity (204) and a low-pressure piston cavity (205) coaxially arranged, the high-pressure piston cavity (204) communicating with the high-pressure oil suction valve (202), and the low-pressure piston cavity (205) communicating with the low-pressure oil suction valve (203); An oil discharge hole (206) inside which is mounted with an oil outlet one-way valve (207) for receiving oil from the high-pressure piston cavity (204) and the low-pressure piston cavity (205) and outputting pressure oil to an actuator.

2. A hand-operated hydraulic pump according to claim 1, wherein The pump body (2) is provided with a first process hole (208) which is arranged in parallel with the oil suction hole (201), and the first process hole (208) communicates with the low-pressure piston cavity (205) through a first inclined hole (209) provided inside the pump body (2).

3. A hand-operated hydraulic pump according to claim 2, wherein The pump body (2) is provided with a second process hole (210) which is perpendicular to the first process hole (208) and the oil suction hole (201), and the second process hole (210) is vertically provided in the first process hole (208) and the oil suction hole (201).

4. A hand-operated hydraulic pump according to claim 1, wherein Further comprising a low-pressure adjusting hole (211) and a high-pressure adjusting hole (212) which are provided in parallel inside the pump body (2), and each of the low-pressure adjusting hole (211) and the high-pressure adjusting hole (212) is mounted with an adjusting valve (213).

5. A hand-operated hydraulic pump according to claim 4, wherein The pump body (2) is provided with a low-pressure overflow hole (214) and a high-pressure overflow hole (215) inside, the low-pressure overflow hole (214) respectively communicating with the low-pressure adjusting hole (211) and the oil tank (1), and the high-pressure overflow hole (215) respectively communicating with the high-pressure adjusting hole (212) and the oil tank (1).

6. A hand-operated hydraulic pump according to claim 4, wherein The pump body (2) is provided with a third process hole (216) which vertically communicates with the oil discharge hole (206), and a pressure sensing oil way (217) which communicates with the third process hole (216), and the pressure sensing oil way (217) vertically communicates with the low-pressure adjusting hole (211).

7. A hand-operated hydraulic pump according to claim 6, wherein The pump body (2) is provided with a pressure relief oil way (218) which is coaxial with the low-pressure adjusting hole (211), and a sealing element (219) is coaxially movably arranged inside the pressure relief oil way (218), and the sealing element (219) can move axially along the pressure relief oil way (218) to block and release the oil inlet of the low-pressure adjusting hole (211).

8. A hand-operated hydraulic pump according to claim 6, wherein The pump body (2) is provided with a second inclined hole (220) which communicates with the third process hole (216), and a pressure gauge (3) is mounted in the second inclined hole (220).

9. A hand-operated hydraulic pump according to claim 1, wherein The pump body (2) is further provided with a return oil hole (221) which communicates with the oil tank (1), and a return oil valve (4) is mounted at the return oil hole (221).

10. A hand-operated hydraulic pump according to claim 1, wherein Also included is a pressing rod (5) hinged to the pump body (2), the pressing rod (5) being fixed with a piston (51), the piston (51) coaxially extending into the piston cavity.

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