Jack

Abstract

The jack relates to the field of hoisting equipment and comprises a cylinder body, an oil storage cavity and a working cavity are formed in the cylinder body, the oil storage cavity is used for storing hydraulic oil, an oil return pipeline is connected between the oil storage cavity and the working cavity, a control valve is arranged in the oil return pipeline, and when the control valve is opened, the oil storage cavity and the working cavity can be communicated through the oil return pipeline; the jacking device is movably arranged in the working cavity in a penetrating mode and can move in the axial direction of the working cavity. The driving cavity is formed in one side of the cylinder body, a driving plunger is movably arranged in the driving cavity, the driving cavity communicates with the oil storage cavity through an oil suction pipe, and the driving cavity communicates with the working cavity through an oil discharge pipe; the electric control device comprises a motor externally connected with a power source, and the driving plunger can be controlled by power of the motor to move in the driving cavity in a reciprocating mode. The manual control device comprises a pressing rod, and the pressing rod can be manually used for controlling the driving plunger to move in the driving cavity in a reciprocating mode. According to the invention, the jacking height error can be reduced while the jacking efficiency is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of lifting equipment, and particularly relates to a jack. Background Art

[0002] As an important lifting tool, the jack is widely used in various occasions, such as power maintenance, bridge repair, heavy object jacking, static pile pressing, foundation settlement, bridge and ship building. The basic working principle of the jack is to use hydraulic oil as the working medium and utilize the change of the sealed volume to transmit motion and power.

[0003] Existing jacks generally adopt manual control to move the pressure rod up and down, thereby realizing the jacking function. During the manual operation process, the control of the jacking height is more accurate, but the manual operation process is time-consuming and laborious, and the efficiency of using the jack to jack heavy objects is relatively low; in order to reduce the manual labor intensity and improve the efficiency, there has currently emerged a pure electric jack controlled by a motor, which liberates the manual operation jacking process. However, the electric jack needs to be manually controlled by a remote controller to start and stop. During the process of manually controlling the remote controller, there is a certain lag, so that during the manual remote control driving process, the jacking plunger of the jack cannot accurately stop at the required height position, and thus a certain error will occur in the jacking height.

[0004] Currently, there is an urgent need to design a jack that can reduce the jacking height error while ensuring the jacking efficiency. Summary of the Invention

[0005] The purpose of the present invention is to provide a jack to solve the above problems existing in the prior art, and can reduce the jacking height error while ensuring the jacking efficiency.

[0006] To achieve the above purpose, the present invention provides the following solutions: The present invention provides a jack, comprising: A cylinder body, in which an oil storage cavity and a working cavity are provided. The oil storage cavity is used for storing hydraulic oil. A return oil pipeline is connected between the oil storage cavity and the working cavity, and a control valve is provided in the return oil pipeline. When the control valve is opened, the oil storage cavity and the working cavity can be communicated through the return oil pipeline; A jacking device, the bottom of which is movably inserted into the working cavity, and can move axially along the working cavity; A driving cavity, which is arranged outside the cylinder body. A driving plunger is movably arranged in the driving cavity, and the driving cavity is communicated with the oil storage cavity through a suction pipeline, and the driving cavity is communicated with the working cavity through a discharge pipeline; An electronic control device, which includes a motor externally connected with a power supply. The motor is connected to one end of the driving plunger through an output end, and can control the driving plunger to reciprocate in the driving cavity with the power of the motor; A manual control device, which includes a pressing rod. The pressing rod is connected to one end of the driving plunger through a connecting end, and the driving plunger can be manually controlled to reciprocate in the driving cavity by using the pressing rod.

[0007] Preferably, there are two driving cavities, namely a first driving cavity and a second driving cavity. One driving plunger is provided in each of the first driving cavity and the second driving cavity; the first driving cavity is communicated with the oil storage cavity through an oil suction pipe, and the second driving cavity is communicated with the oil storage cavity through another oil suction pipe; the first driving cavity is communicated with the working cavity through a drain pipe, and the second driving cavity is communicated with the working cavity through another drain pipe; the electric control device can control the driving plunger in the first driving cavity to reciprocate in the first driving cavity with the power of the motor; the manual control device can manually control the driving plunger in the second driving cavity to reciprocate in the second driving cavity by using the pressing rod.

[0008] Preferably, the electric control device further includes an elastic member and a cam. The cam is fixedly sleeved on the camshaft, one end of the output end of the motor is in transmission connection with one end of the camshaft through a coupling, and the outer edge of the cam abuts against one end of the driving plunger in the first driving cavity; the end of the driving plunger away from the cam is connected to the bottom of the first driving cavity through the elastic member.

[0009] Preferably, the electric control device further includes a connecting rod and a cam. The cam is fixedly sleeved on the camshaft, one end of the output end of the motor is in transmission connection with one end of the camshaft through a coupling, a cam rod is fixedly provided on the side surface of the cam away from the motor, the cam rod is parallel to the camshaft, the cam rod is rotatably connected to one end of the connecting rod, and the end of the connecting rod away from the cam rod is hinged to the driving plunger in the first driving cavity.

[0010] Preferably, the manual control device further includes a sleeve and a support rod. The support rod is hinged to the outer side wall at the top of the second driving cavity. One end of the sleeve is hinged to the support rod, and the other end is used for inserting the connecting end of the pressing rod; the side wall below the sleeve is hinged to the top end of the driving plunger in the second driving cavity.

[0011] Preferably, the electric control device further includes a controller. The controller is connected to the motor, and the controller can control the rotation speed of the motor.

[0012] Preferably, the power source is a storage battery. A battery cavity is provided at the bottom outside the cylinder body, and the storage battery is fixedly provided in the battery cavity. The storage battery is electrically connected to the motor.

[0013] Preferably, a reset bolt is threadedly connected to the outer side wall of the cylinder block. The reset bolt is coaxial with the control valve of the oil return pipeline, and one end of the reset bolt is fixedly connected to the control valve, and the other end can be clamped with the end of the pressure rod. The pressure rod can drive the control valve to axially reciprocate through the reset bolt, and the control valve can move towards the oil return pipeline to close the oil return pipeline or move in the reverse direction to conduct the oil return pipeline.

[0014] Preferably, the control valve is a solenoid valve, and the solenoid valve can conduct the oil return pipeline when it is opened. The solenoid valve is externally connected with a control switch, and the control switch can control the solenoid valve to be opened or closed.

[0015] Preferably, it further includes a support frame. The support frame includes a support rod. A plurality of obliquely arranged support rods are annularly arranged outside the cylinder block. The upper end of the support rod is connected to the side wall of the cylinder block, and a universal wheel is provided at the bottom end of the support rod.

[0016] The present invention has achieved the following technical effects compared with the prior art: The jack of the present invention is based on Pascal's principle. By electrically controlled or manually controlled driving, the plunger reciprocates in the driving cavity, so that the hydraulic oil in the oil storage cavity is transmitted to the working cavity through the driving cavity, and the hydraulic oil is used to drive the lifting device in the working cavity to rise, realizing the lifting function of heavy objects. When the present invention is in use, in the early stage, an electric control device can be used to quickly control the reciprocating movement of the driving plunger to realize the rapid rise of the lifting device, improve work efficiency and reduce manual labor intensity. When approaching the required lifting height position, stop the electric control device and use a manual control device to slowly control the reciprocating movement of the driving plunger, so that the lifting device rises slowly and is finely adjusted at a close distance, so that the lifting device can accurately reach the required height position and improve the lifting accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of the jack in one or some embodiments of the present invention; Figure 2 It is a side view of the jack in one or some embodiments of the present invention.

[0019] In the figure: 1 - support rod, 2 - universal wheel, 3 - cylinder block, 4 - lifting device, 5 - motor, 6 - pressure rod, 7 - reset bolt, 8 - driving plunger, 9 - controller, 10 - battery chamber, 11 - driving chamber. Detailed implementation manner

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The purpose of the present invention is to provide a jack to solve the problems existing in the above-mentioned prior art, and while ensuring the lifting efficiency, it can reduce the lifting height error.

[0022] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0023] Currently, general jacks generally include a manual mechanical drive structure and an electric fully automatic drive structure. For the manual drive structure, the lifting speed of the lifting device of the jack is slow, and it can accurately stay at the required height position. However, during its lifting process, it is necessary to manually control the reciprocating movement of the pressure rod, which is time-consuming and laborious, and the efficiency is low; while the electric drive structure does not require manual drive and has high efficiency. However, since manual operation of the remote control is required to start and stop during electric drive, there is a certain lag during the process of manually operating the remote control. When the lifting device reaches the required height position, it often cannot stop in time, that is, there is a certain lag when manually controlling the start and stop switch of the motor, resulting in the lifting device being unable to accurately stay at the required height position, resulting in a certain error.

[0024] To solve the above problems, while ensuring the improvement of work efficiency, the requirement of reducing errors can also be met. Therefore, the present invention provides a jack, such as Figure 1 and Figure 2As shown in the figure, it includes a support frame, a cylinder block 3, a jacking device 4, a drive chamber 11, an electric control device, and a manual control device; the cylinder block 3 is fixedly arranged on the support frame, and an oil storage chamber and a working chamber are provided inside the cylinder block 3. In this embodiment, the cylinder block 3 is a vertically arranged cylindrical structure, and its interior is the oil storage chamber. A working cylinder coaxial with the cylinder block 3 is fixedly sealed inside the oil storage chamber, and the internal space of the working cylinder forms the working chamber. The top of the working cylinder is located outside the cylinder block 3 or flush with the upper surface of the cylinder block 3, and the top of the working cylinder is open; the oil storage chamber is used to store hydraulic oil. There is no direct connection relationship between the working chamber and the oil storage chamber itself. An oil return pipeline is connected between the oil storage chamber and the working chamber, and a control valve is provided on the oil return pipeline. When the control valve is opened, the oil storage chamber and the working chamber can be conducted through the oil return pipeline; the lower part of the jacking device 4 movably penetrates into the working chamber, and it can move axially along the working chamber. The specific structure of the jacking device 4 and its connection relationship with the working chamber belong to known structures. In this embodiment, the jacking device 4 uses a jacking plunger, and the bottom of the jacking plunger is connected to the inside of the working chamber and is in sealed contact with the inner side wall of the working chamber; the drive chamber 11 is arranged on one side of the cylinder block 3. A drive plunger 8 is movably arranged inside the drive chamber 11, and the drive chamber 11 is communicated with the oil storage chamber through an oil suction pipe, and the drive chamber 11 is communicated with the working chamber through an oil discharge pipe. Both the oil suction pipe and the oil discharge pipe are one-way conduction pipelines, which belong to known structures. A one-way valve is respectively provided on the oil suction pipe and the oil discharge pipe. The one-way valve on the oil suction pipe enables the hydraulic oil in the oil storage chamber to flow into the drive chamber 11 through the oil suction pipe and cannot flow reversely; the one-way valve on the oil discharge pipe enables the hydraulic oil in the drive chamber 11 to flow into the working chamber through the oil discharge pipe and cannot flow reversely; the electric control device includes a controller 9 and a motor 5 with an external power supply. The controller 9 is a structure in the prior art and can control the reciprocating movement of the drive plunger 8 in the drive chamber 11 with the power of the motor 5. In this embodiment, the power supply is a storage battery, or a 24-volt battery can also be used. A battery chamber 10 is provided at the outer bottom of the cylinder block 3, and a storage battery or a battery is fixedly arranged inside the battery chamber 10. The storage battery or the battery is electrically connected to the motor 5. The motor 5 can use a linear motor, and its output end is directly connected to one end of the drive plunger 8, which can realize the linear reciprocating movement of the drive plunger 8; the manual control device includes a pressure rod 6, which can manually control the reciprocating movement of the drive plunger 8 in the drive chamber 11 with the pressure rod 6. When the drive plunger 8 moves in the drive chamber 11 in a direction away from the drive chamber 11, it can suck the hydraulic oil in the oil storage chamber into the drive chamber 11 through the oil suction pipe. When the drive plunger 8 moves in the drive chamber 11 in a direction close to the bottom of the drive chamber 11, it can squeeze the hydraulic oil in the drive chamber 11 into the working chamber through the oil discharge pipe.

[0025] The jack of the present invention is based on Pascal's principle, and the inner diameter of the working chamber is larger than the inner diameter of the driving chamber 11; it adopts a combination of electric control and manual control. When in use, the electric control device can be used to quickly control the reciprocating movement of the driving plunger 8 in the early stage to achieve rapid ascent of the jacking device 4, thereby improving work efficiency and reducing manual labor intensity. When the desired jacking height is about to be reached, the electric control device is stopped, and the manual control device is used to slowly control the reciprocating movement of the driving plunger 8, so that the jacking device 4 rises slowly, and is fine-tuned at close range, so that the jacking device 4 can accurately reach the desired height position, thereby improving the accuracy of the jacking position.

[0026] In order to realize the separate control of electric control and manual control without interference between the two, the present embodiment designs two driving chambers 11, namely the first driving chamber and the second driving chamber, each of which is provided with a driving plunger 8; the first driving chamber is connected with the oil storage chamber through an oil suction pipe, and the second driving chamber is connected with the oil storage chamber through another oil suction pipe; the first driving chamber is connected with the working chamber through an oil discharge pipe, and the second driving chamber is connected with the working chamber through another oil discharge pipe; the electric control device can control the driving plunger 8 in the first driving chamber to reciprocate in the first driving chamber by the power of the motor 5; the electric control device of the present embodiment also includes an elastic member and a cam, the cam is fixedly penetrated on the camshaft, the motor 5 is arranged vertically, and the output shaft at the bottom thereof is connected to one end of the camshaft through a coupling, the cam of the present embodiment is horizontally distributed, and its camshaft is vertically connected to the cam; The axis of the dynamic cavity is horizontally distributed, and the outer edge of the cam abuts against one end of the driving plunger 8 in the first driving cavity; the elastic member is located in the first driving cavity and is coaxial with the first driving cavity. The end of the driving plunger 8 away from the cam abuts against the bottom of the first driving cavity through the elastic member. The motor 5 is externally connected to the controller 9, and the motor 5 is manually started by pressing the button of the controller 9. When the motor 5 drives the cam to rotate, the irregular outer edge of the cam is always in contact with the outer end of the driving plunger 8. When the outer convex part of the cam abuts against the end of the driving plunger 8, the other end of the driving plunger 8 is pushed to squeeze the elastic member and shrink into the first driving cavity. When the cam rotates to the outer edge of the other end toward the driving plunger 8, the elastic force of the elastic member drives the driving plunger 8 to move away from the first driving cavity, thereby using the cam profile and the elastic member to control the driving plunger 8 to perform periodic reciprocating motion in the first driving cavity, and converting the rotary power into linear motion. The structure of the elastic member is not limited. The elastic member of this embodiment adopts a spring, and can also adopt an elastic rod or an elastic rubber block, which can also achieve the above functions.

[0027] Since the elasticity of the elastic member will restrict the working process of the driving plunger 8, to solve this problem, in another embodiment, the electronic control device no longer uses an elastic member. The electronic control device of this embodiment further includes a connecting rod. The cam is fixedly sleeved on the camshaft. The output shaft of the motor 5 is drivingly connected to one end of the camshaft through a coupling. A cam rod is fixedly provided on the side of the cam away from the motor 5. The cam rod is parallel to the camshaft. One end of the cam rod is rotatably connected to the connecting rod. The end of the connecting rod away from the cam rod is hinged to the driving plunger 8 in the first driving cavity. The motor 5 controls the rotation of the disc-shaped cam. The camshaft drives the connecting rod to swing. The connecting rod controls the driving plunger 8 to reciprocate linearly along the first driving cavity. Only the power of the motor 5 is used, without an additional spring structure, so that the control process is more accurate.

[0028] The manual control device of this embodiment can manually control the driving plunger 8 in the second driving cavity to reciprocate in the second driving cavity by using the pressing rod 6; specifically, the manual control device includes a sleeve and a support rod. The bottom of the support rod is hinged to the outer side wall of the top of the second driving cavity. The sleeve is arranged obliquely. One end of the sleeve is hinged to the top of the support rod. The other end of the sleeve is used for inserting the pressing rod 6. An extension block is provided on the lower side wall of the sleeve. The extension block is hinged to the top end of the driving plunger 8 in the second driving cavity. Insert one end of the pressing rod 6 into the sleeve, and manually hold the pressing rod 6 and move it up and down, so that the sleeve swings up and down around the position of the support rod, and the lever principle is used to meet the labor-saving requirement. During the process, the sleeve drives the vertically arranged driving plunger 8 to reciprocate linearly up and down along the vertically arranged second driving cavity.

[0029] When the control valve is opened, the oil return pipeline can be conducted. Under the gravity of the jacking device 4, the hydraulic oil in the working chamber is squeezed, so that the hydraulic oil flows back from the working chamber to the oil storage chamber. When the control valve is closed, the oil return pipeline is closed and the hydraulic oil cannot flow. In this embodiment, a reset bolt 7 is threadedly connected to the outer side wall of the cylinder block 3. The reset bolt 7 is coaxial with the control valve of the oil return pipeline, and one end of the reset bolt 7 is fixedly connected to the control valve, and the other end can be clamped with the end of the pressure rod 6; a clamping block is provided at the end of the pressure rod 6. The pressure rod 6 is taken out of the sleeve, and then the clamping block of the pressure rod 6 is clamped to the outer end of the reset bolt 7. The pressure rod 6 is rotated so that the reset thread synchronously rotates along the thread in the cylinder block 3, and thus the control valve can be driven to axially move forward or backward by the reset bolt 7. The control valve in this embodiment is similar to a plug structure or a closed plug structure. It penetrates through the side wall of the oil return pipeline and is hermetically connected to the side wall of the oil return pipeline at the penetration position. When the control valve moves forward, it can completely enter the interior of the oil return pipeline until the oil return pipeline is closed. When the reset bolt 7 moves backward, it can drive the control valve to move in the reverse direction. The control valve gradually disengages from the interior of the oil return pipeline until the oil return pipeline is conducted, realizing the conduction of the oil return pipeline. In order to prevent the control valve from completely disengaging from the side wall of the oil return pipeline and causing hydraulic oil leakage, a limit protrusion is fixedly provided at one end of the control valve located in the oil return pipeline. When the oil return valve moves in the direction of disengaging from the oil return pipeline, when it moves to the position where the limit protrusion abuts against the inner side wall of the oil return pipeline, it reaches the limit position and the oil return valve cannot move further. At this time, the interior of the oil return pipeline is conducted and the hydraulic oil will not leak from the connection position between the oil return pipeline and the control valve.

[0030] In another embodiment, the pressure relief process can also adopt an electric control method to further improve the efficiency. The control valve in this embodiment is a solenoid valve that can conduct unidirectionally, that is, a one-way solenoid valve. When it is opened, it can conduct the oil return pipeline unidirectionally, so that the hydraulic oil can only flow back from the working chamber to the oil storage chamber and cannot flow reversely; a control switch is externally connected to the solenoid valve. The control switch belongs to the prior art. The control switch can control the opening or closing of the solenoid valve. The control switch uses a wireless remote control or a wired handle to send an instruction to the solenoid valve to control the energization of the coil of the solenoid valve, the movement of the valve core, and the opening of the solenoid valve, thereby conducting the oil return pipeline. The hydraulic oil in the working chamber flows back to the oil storage chamber to complete the function of the jack pressure relief and descent.

[0031] In order to make the support of the device of the present invention more stable, three groups of support rods 1 are used for the support frame. The three groups of support rods 1 are arranged around the outer side of the cylinder block 3 and are inclined. The upper ends of the support rods 1 are fixedly connected or hinged to the side wall of the cylinder block 3 to realize triangular support and improve stability. The three groups of support rods 1 can also be connected to each other to further improve the firmness; in order to make the device of the present invention easy to move, in one embodiment, universal wheels 2 are provided at the bottom ends of the support rods 1, and the whole device can be conveniently driven to move to the required position.

[0032] The present invention is applicable to hoisting, supporting, etc. during the maintenance of equipment such as vehicles and aircraft. When working in the wild, it can be lifted and lowered manually. The mechanical power is used to manually control the pressure rod, and the mechanical structure drives the drive plunger 8 to reciprocate along the axis of the drive chamber, thereby driving the lifting device 4 to lift and lower. In order to improve efficiency, electric control can be adopted. The motor uses a cam to drive the drive plunger 8 to reciprocate along the axis of the drive chamber, so that the lifting device 4 can quickly lift and lower a certain height, and then the remaining part of the lifting is controlled manually and mechanically for fine adjustment at close range, with high flexibility. The electric control and manual control can be used in cooperation according to different task scenarios; it can also operate independently with electric control or manual control to meet diverse requirements.

[0033] Specific examples are applied in the present invention to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A jack, characterized in that: include: A cylinder body, wherein an oil storage chamber and a working chamber are provided in the cylinder body, wherein the oil storage chamber is used to store hydraulic oil, an oil return pipeline is connected between the oil storage chamber and the working chamber, and a control valve is provided in the oil return pipeline, and when the control valve is opened, the oil storage chamber and the working chamber can be connected through the oil return pipeline; A lifting device, the bottom of which is movably arranged in the working chamber and can move axially along the working chamber; A driving chamber is arranged outside the cylinder body, a driving plunger is movably arranged in the driving chamber, and the driving chamber is connected with the oil storage chamber through an oil suction pipe, and the driving chamber is connected with the working chamber through an oil discharge pipe; the driving chamber is provided with two, namely a first driving chamber and a second driving chamber, and the first driving chamber and the second driving chamber are each provided with a driving plunger; The electric control device can control the driving plunger in the first driving cavity to reciprocate in the first driving cavity by using the power of the motor; An electric control device, comprising a motor connected to an external power source, wherein the motor is connected to one end of the driving plunger via an output end, and can control the driving plunger to reciprocate in the driving cavity by the power of the motor; The manual control device comprises a pressure rod, which is connected to one end of the driving plunger through a connecting end, and the pressure rod can be used to manually control the driving plunger to reciprocate in the driving chamber; a reset bolt is threadedly connected to the outer wall of the cylinder body, and the reset bolt is coaxial with the control valve of the return oil pipeline, and one end of the reset bolt is fixedly connected to the control valve, and the other end can be clamped with the end of the pressure rod; the pressure rod can drive the control valve to reciprocate axially through the reset bolt, and the control valve can move toward the direction close to the return oil pipeline to close the return oil pipeline or move in the opposite direction to open the return oil pipeline; the electronic control device also includes an elastic member and a cam, the cam is fixedly penetrated on the camshaft, the output end of the motor is transmission-connected to one end of the camshaft through a coupling, and the outer edge of the cam abuts against one end of the driving plunger in the first driving chamber; One end of the driving plunger away from the cam is connected to the bottom of the first driving cavity through the elastic member.

2. The jack according to claim 1, characterized in that: The first drive chamber is connected to the oil storage chamber through an oil suction pipe, and the second drive chamber is connected to the oil storage chamber through another oil suction pipe; the first drive chamber is connected to the working chamber through an oil discharge pipe, and the second drive chamber is connected to the working chamber through another oil discharge pipe; the manual control device can manually use the pressing rod to control the driving plunger in the second drive chamber to reciprocate in the second drive chamber.

3. The jack according to claim 2, characterized in that: The electronic control device also includes a connecting rod and a cam, wherein the cam is fixedly inserted into the camshaft, and the output end of the motor is transmission-connected to one end of the camshaft via a coupling, and a cam rod is fixedly provided on the side of the cam away from the motor, and the cam rod is parallel to the camshaft, and the cam rod is rotationally connected to one end of the connecting rod, and the end of the connecting rod away from the cam rod is hinged to the driving plunger in the first driving chamber.

4. The jack according to claim 2, characterized in that: The manual control device further includes a sleeve and a support rod. The support rod is hinged to the outer side wall at the top of the second drive chamber. One end of the sleeve is hinged to the support rod, and the other end is used for inserting the connection end of the pressure rod. The lower side wall of the sleeve is hinged to the top end of the drive plunger in the second drive chamber.

5. The jack according to claim 1 or 3, characterized in that: The electric control device further includes a controller, the controller is connected to the motor, and the controller can control the rotation speed of the motor.

6. The jack according to claim 1, characterized in that: The power supply is a storage battery. A battery chamber is provided at the outer bottom of the cylinder block, and the storage battery is fixedly provided in the battery chamber. The storage battery is electrically connected to the motor.

7. The jack according to claim 1, characterized in that: The control valve is a solenoid valve. When the solenoid valve is opened, it can conduct the oil return pipeline. The solenoid valve is externally connected with a control switch, and the control switch can control the opening or closing of the solenoid valve.

8. The jack according to claim 1, characterized in that: It further includes a support frame. The support frame includes a support rod. A plurality of inclined support rods are arranged in a ring outside the cylinder block. The upper end of the support rod is connected to the side wall of the cylinder block, and a universal wheel is provided at the bottom end of the support rod.

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