High-low pressure double-speed electric hydraulic jack

Abstract

The utility model discloses a high-low pressure double-speed electric hydraulic jack, which comprises a jack seat body, an oil cylinder and an oil tank, an oil inlet path, a gear pump and a plunger pump are arranged in the jack seat body, a main shaft is rotatably arranged in the jack seat body, the main shaft is in transmission connection with a driving mechanism, the gear pump is arranged on the main shaft, and the plunger pump is arranged on the oil cylinder. The main shaft is further provided with a cam, the plunger pump is in linkage with the cam, and the plunger pump can be pushed by the cam to do piston motion. According to the high-low pressure double-speed electric hydraulic jack, two-way large-flow oil feeding is achieved in the no-load period and the low pressure period, and the jack can ascend rapidly; according to the high-low-pressure double-speed electric hydraulic jack, single-path small-flow oil inlet is achieved in the loading and high-pressure periods, the jacking speed is reduced, the jacking process is more stable, the high-low-pressure double-speed electric hydraulic jack has the advantages of being high in operation efficiency and safe in operation, more convenient and easy to use, coaxial installation is achieved, and the installation structure driven by the same driving mechanism is more compact and more reasonable in layout.

Description

Technical Field

[0001] The utility model relates to the technical field of jack equipment, in particular to a high-low pressure double-speed electric hydraulic jack. Background Art

[0002] As a light and small lifting device, the jack is widely used in the automotive repair field. The structure of the jack, as disclosed in the patent document with the Chinese patent application number 201120249907.3, generally includes an oil cylinder, an oil tank and a pump body. During operation, the oil in the oil tank is pumped into the oil cylinder through the pump body, and the oil cylinder rises after the oil enters. The change of the jacking pressure during the rising process is that in the early stage of rising, especially in the no-load period before jacking the load, the jacking pressure is relatively small; after jacking the load, affected by the gravity of the load, the jacking pressure increases. This change characteristic of the jacking pressure during the rising process makes it appropriate to control the jacking operation as follows: in the early stage of no-load or low pressure, large-flow oil inlet is used to achieve rapid rising; in the later stage of high pressure, small-flow oil inlet is used to achieve stable rising of the load. However, most of the existing jacks adopt a single pump body, and the single oil inlet volume of the pump body is the same. During the operation process, the flow control can often only be achieved by adjusting the pump pressure frequency. For example, in the early stage of no-load or low pressure, in order to achieve large-flow oil inlet and rapid rising, the pump body often has to be pumped quickly, and the formation of a relative control relationship between the jacking pressure and the pump pressure frequency of the pump body is relatively cumbersome and cannot be achieved by a simple oil circuit. It often involves a computer control system, resulting in high implementation difficulty and high cost. Therefore, such jacks are not currently available. That is to say, the existing jacks still do not have the flow control according to the pressure size, and their use effect is poor and the operation stability is low. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a high-low pressure double-speed electric hydraulic jack.

[0004] The technical solution for achieving the purpose of the utility model is: a high-low pressure double-speed electric hydraulic jack, which includes a jack seat body, an oil cylinder and an oil tank. An oil inlet oil circuit, a gear pump and a plunger pump are arranged in the jack seat body. The oil inlet oil circuit includes a main oil circuit, a first oil circuit, a second oil circuit and a third oil circuit. The oil tank and the oil inlet end of the gear pump are connected through the main oil circuit. The first oil circuit and the second oil circuit are connected in parallel between the oil outlet end of the gear pump and the oil cylinder. The plunger pump is located on the second oil circuit. The oil outlet end of the gear pump and the oil tank are also connected through the third oil circuit. A first pressure relief valve is installed on the third oil circuit.

[0005] A main shaft is rotatably installed in the jack seat body. The main shaft is in transmission connection with a driving mechanism and is driven by the driving mechanism to rotate. The gear pump is installed on the main shaft, and a cam is also installed on the main shaft. The plunger pump is linked with the cam and is pushed by the cam to perform piston movement.

[0006] Further, the oil outlet end of the plunger pump is communicated with the fuel tank through a fourth oil passage, and a second pressure relief valve is installed on the fourth oil passage. During the working process, after the first pressure relief valve is opened, oil enters with a small single-path flow through the second oil passage. As the oil pressure in the oil cylinder further increases and the jack reaches the upper limit, when the oil pressure in the oil cylinder is too high, the second pressure relief valve is pressed to open, and the oil pumped by the plunger pump on the second oil passage returns to the fuel tank through the fourth oil passage and no longer enters the oil cylinder. The second pressure relief valve plays a protective role to ensure operation safety.

[0007] Further, the driving mechanism is a motor.

[0008] Further, the main shaft is of an integral or split structure.

[0009] Further, a first one-way valve is provided on the main oil passage. The setting of the first one-way valve can ensure that the oil passage on the main oil passage can only be unidirectionally conducted from the fuel tank to the gear pump. In this way, it is convenient to control the system.

[0010] Further, a second one-way valve is provided on the second oil passage. The setting of the second one-way valve can ensure that the oil passage on the second oil passage can only be unidirectionally conducted from the plunger pump to the oil cylinder. In this way, it is convenient to control the system.

[0011] In the high-low speed electric hydraulic jack of the present utility model, by arranging the gear pump and the plunger pump in the jack seat body, conditions are provided for the variable and adjustable oil inlet flow rate of the double pump composed of the gear pump and the plunger pump. On this basis, combined with the use of the first pressure relief valve, the first pressure relief valve is used as an adjustment switch for the oil inlet flow rate, and the oil pressure in the oil cylinder is used as the adjustment basis. As the oil pressure in the oil cylinder changes, the oil inlet flow rate of the jack is automatically adjusted. For example, in the low-pressure state in the early stage of jacking, the first pressure relief valve is not opened and is in a closed state. The gear pump and the plunger pump act together, and oil enters with a large double-path flow through the first oil passage and the second oil passage, that is, low-pressure large-flow oil inlet; as jacking progresses and the pressure gradually increases, in the high-pressure state in the later stage, the first pressure relief valve is pressed to open and the third oil passage is conducted. At this time, only oil enters with a small single-path flow through the second oil passage, that is, high-pressure small-flow oil inlet.

[0012] The high-low voltage dual-speed electric hydraulic jack of the utility model automatically adjusts the oil inlet flow rate into the oil cylinder during the jacking process as the pressure increases. During the no-load and low-pressure periods, dual-channel large-flow oil inlet is provided, enabling the jack to rise quickly; during the load-bearing and high-pressure periods, single-channel small-flow oil inlet is used to reduce the jacking speed and make the jacking process more stable. Among them, the rapid rise during the low-pressure period improves the operation efficiency; the stable operation during the high-pressure period ensures the operation safety. That is to say, the high-low voltage dual-speed electric hydraulic jack of the utility model takes into account both the operation efficiency and the operation safety, and is more convenient and easy to use.

[0013] In addition, for the high-low voltage dual-speed electric hydraulic jack of the utility model, the gear pump and the cam that drives the plunger pump are installed on the same main shaft and are driven by the driving mechanism at the same time. The installation structure with coaxial installation and driven by the same driving mechanism is also more compact. For a jack with a relatively small volume of the jack seat body, its compact layout is also more reasonable. Brief Description of the Drawings

[0014] Figure 1 is a schematic diagram of the oil inlet path structure of the high-low voltage dual-speed electric hydraulic jack of the utility model;

[0015] Figure 2 is a schematic diagram of the installation structure of the gear pump and the plunger pump of the high-low voltage dual-speed electric hydraulic jack of the utility model. Detailed Embodiment

[0016] The following is a detailed description of the preferred embodiment of the high-low voltage dual-speed electric hydraulic jack of the utility model in conjunction with the drawings:

[0017] As Figure 1 and Figure 2 shown, a high-low voltage dual-speed electric hydraulic jack includes a jack seat body 1, an oil cylinder 2, and an oil tank 3. An oil inlet oil path, a gear pump 5, and a plunger pump 6 are provided inside the jack seat body 1. The oil inlet oil path includes a main oil path 40, a first oil path 41, a second oil path 42, and a third oil path 43. The oil tank 3 and the oil inlet end 51 of the gear pump 5 are connected through the main oil path 40. The first oil path 41 and the second oil path 42 are connected in parallel between the oil outlet end 52 of the gear pump 5 and the oil cylinder 2. The plunger pump 6 is located on the second oil path 42. The oil outlet end 52 of the gear pump 5 is also connected to the oil tank 3 through the third oil path 43. A first pressure relief valve 101 is installed on the third oil path 43;

[0018] A main shaft 7 is rotatably installed in the jack seat body 1. The main shaft 7 is in transmission connection with a driving mechanism 8 and is driven to rotate by the driving mechanism 8. The gear pump 5 is installed on the main shaft 7. A cam 60 is also installed on the main shaft 7. The plunger pump 6 is linked with the cam 60 and is pushed by the cam 60 to perform piston movement.

[0019] For the high-low speed dual-speed electric hydraulic jack of the present utility model, the gear pump 5 and the cam 60 that pushes the plunger pump 6 are installed on the same main shaft 7. Driven by the driving mechanism 8, the main shaft 7 rotates, driving the gear pump 5 to perform pumping pressure while also driving the cam 60 to rotate. The rotating cam 60 pushes the plunger pump 6, causing the plunger pump 6 to also perform pumping pressure action. That is to say, driven by the driving mechanism 8, the gear pump 5 and the plunger pump 6 can be driven to act simultaneously.

[0020] For the high-low speed dual-speed electric hydraulic jack of the present utility model, the plunger pump 6 is located on the second oil path 42. The inlet end 61 of the plunger pump 6 is communicated with the outlet end of the gear pump 5 through the second oil path 42, and the outlet end 62 of the plunger pump 6 is communicated with the oil cylinder 2 through the second oil path 42. During operation, driven by the driving mechanism 8, the gear pump 5 and the plunger pump 6 act together to pump the oil in the fuel tank 3 into the oil cylinder 2 to realize the jacking of the jack. Specifically, under the pumping pressure of the gear pump 5, the oil in the fuel tank 3 first enters the gear pump 5 from the main oil path 40, and then is pumped out from the outlet end 52 of the gear pump 5.

[0021] In the early stage of jacking, the oil pressure in the oil cylinder 2 is in a low-pressure state. The oil pumped out by the gear pump 5 enters the first oil path 41 all the way and is directly pumped into the oil cylinder 2 by the gear pump 5; the other way enters the second oil path 42 and is pumped into the oil cylinder 2 by the plunger pump 6. The first oil path 41 and the second oil path 42 have dual-channel large-flow oil inlet.

[0022] In the later stage of jacking, the oil pressure in the oil cylinder 2 is in a high-pressure state. The first pressure relief valve 101 is pressed and opened, and the third oil path 43 is conducted. The oil flowing out of the gear pump 5 enters the third oil path 43 all the way and is pumped back into the fuel tank 3 by the gear pump 5; the other way enters the second oil path 42 and is pumped into the oil cylinder 2 by the plunger pump 6. The second oil path 42 has single-channel small-flow oil inlet.

[0023] The high-low voltage two-speed electric hydraulic jack of the present utility model provides conditions for the variable and adjustable oil inlet flow by arranging the gear pump 5 and the plunger pump 6 in the jack seat body 1. On this basis, combined with the use of the first pressure relief valve 101, the first pressure relief valve 101 is used as the adjustment switch for the oil inlet flow, and the oil pressure in the oil cylinder 2 is used as the adjustment basis. As the oil pressure in the oil cylinder 2 changes, the oil inlet flow of the jack is automatically adjusted. For example, in the low-pressure state in the early stage of jacking, the first pressure relief valve 101 is not opened and is in a closed state. The gear pump 5 and the plunger pump 6 act together, and large-flow oil inlet is carried out through two paths, namely the first oil path 41 and the second oil path 42, that is, large-flow oil inlet at low pressure. As jacking progresses and the pressure gradually increases, in the high-pressure state in the later stage, the first pressure relief valve 101 is pressed to open, and the third oil path 43 is conducted. At this time, only small-flow oil inlet is carried out through a single path of the second oil path 42, that is, small-flow oil inlet at high pressure.

[0024] During the jacking process of the high-low voltage two-speed electric hydraulic jack of the present utility model, as the pressure increases, the oil inlet flow into the oil cylinder 2 is automatically adjusted. During the no-load and low-pressure periods, large-flow oil inlet through two paths enables the jack to rise quickly; during the load-bearing and high-pressure periods, small-flow oil inlet through a single path reduces the jacking speed and makes the jacking process more stable. Among them, the rapid rise during the low-pressure period improves the operation efficiency; the stable operation during the high-pressure period ensures the operation safety. That is to say, the high-low voltage two-speed electric hydraulic jack of the present utility model takes into account both the operation efficiency and the operation safety, and is more convenient and easy to use.

[0025] In addition, for the high-low voltage two-speed electric hydraulic jack of the present utility model, the gear pump 5 and the cam 60 that drives the plunger pump 6 are installed on the same main shaft 7 and are driven by the same driving mechanism 8 at the same time. The installation structure of coaxial installation and being driven by the same driving mechanism 8 is more compact. For a jack with a relatively small volume of the jack seat body 1, its compact layout is more reasonable.

[0026] Preferably, for the high-low voltage two-speed electric hydraulic jack of the present utility model, the oil outlet end 62 of the plunger pump 6 is communicated with the fuel tank 3 through a fourth oil path 44, and a second pressure relief valve 102 is installed on the fourth oil path 44. During the working process, after the first pressure relief valve 101 is opened, small-flow oil inlet is carried out through a single path of the second oil path 42. As the oil pressure in the oil cylinder 2 further increases and the jack reaches the upper limit, when the oil pressure in the oil cylinder 2 is too high, the second pressure relief valve 102 is pressed to open, and the oil pumped by the plunger pump 6 on the second oil path 42 returns to the fuel tank 3 through the fourth oil path 44 and no longer enters the oil cylinder 2. The second pressure relief valve 102 plays a protective role to ensure the operation safety.

[0027] The high-low voltage dual-speed electric hydraulic jack of the present utility model, the pressure threshold value at which the first pressure relief valve 101 opens is less than the pressure threshold value at which the second pressure relief valve 102 opens. That is to say, as the oil inlet and the oil pressure increase, after reaching the pressure threshold value at which the first pressure relief valve 101 opens, the first pressure relief valve 101 opens; continue to feed oil, the oil pressure continues to rise, and after reaching the pressure threshold value at which the second pressure relief valve 102 opens, the second pressure relief valve 102 opens.

[0028] For the high-low voltage dual-speed electric hydraulic jack of the present utility model, the driving mechanism 8 is a motor.

[0029] For the high-low voltage dual-speed electric hydraulic jack of the present utility model, the main shaft 7 can be an integral structure or a split structure.

[0030] For the high-low voltage dual-speed electric hydraulic jack of the present utility model, preferably, a first one-way valve 201 is provided on the main oil path 40. The setting of the first one-way valve 201 can ensure that the oil path on the main oil path 40 can only be conducted unidirectionally from the fuel tank to the gear pump 5, so that it is convenient to control the system.

[0031] For the high-low voltage dual-speed electric hydraulic jack of the present utility model, preferably, a second one-way valve 202 is provided on the second oil path 42. The setting of the second one-way valve 202 can ensure that the oil path on the second oil path 42 can only be conducted unidirectionally from the plunger pump 6 to the oil cylinder 2, so that it is convenient to control the system.

[0032] For the high-low voltage dual-speed electric hydraulic jack of the present utility model, the gear pump 5 includes a driving gear and a driven gear that mesh with each other, wherein the driving gear is installed on the main shaft 7. The gear pump 5, the plunger pump 6, the first pressure relief valve 101 and the second pressure relief valve 102 are all conventional structures in the prior art, and no further elaboration will be made in this application.

[0033] For those of ordinary skill in the technical field to which the present utility model pertains, without departing from the concept of the present utility model, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present utility model.

Claims

1. A high-low pressure dual-speed electro-hydraulic jack, comprising a jack base body, an oil cylinder and an oil tank, characterized in that: An oil inlet circuit, a gear pump and a plunger pump are provided in the jack seat body, the oil inlet circuit includes a main oil circuit, a first oil circuit, a second oil circuit and a third oil circuit, the oil tank and the oil inlet end of the gear pump are connected through the main oil circuit, the first oil circuit and the second oil circuit are connected in parallel between the oil outlet end of the gear pump and the oil cylinder, the plunger pump is located on the second oil circuit, the oil outlet end of the gear pump is also connected to the oil tank through the third oil circuit, and a first pressure relief valve is installed on the third oil circuit; A main shaft is rotatably mounted in the jack seat, the main shaft is in transmission connection with a driving mechanism and is driven to rotate by the driving mechanism, the gear pump is mounted on the main shaft, a cam is also mounted on the main shaft, the plunger pump is linked with the cam and is driven by the cam to perform piston movement.

2. The high-low speed dual-speed electro-hydraulic jack according to claim 1, characterized in that: The oil outlet end of the plunger pump is connected to the oil tank via a fourth oil circuit, and a second pressure relief valve is installed on the fourth oil circuit.

3. The high-low speed electric-hydraulic jack according to claim 1, wherein: The driving mechanism is a motor.

4. The high-low speed dual-speed electro-hydraulic jack according to claim 1, wherein: The main shaft is an integrated or split structure.

5. The high-low speed electric-hydraulic jack according to claim 1, characterized in that: The main oil circuit is provided with a first one-way valve.

6. The high-low speed dual-speed electro-hydraulic jack according to claim 1, wherein: A second one-way valve is provided on the second oil circuit.

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