Accurate oil supply hydraulic device

Abstract

The utility model discloses an accurate oil supply hydraulic device which comprises a hydraulic cylinder part and a servo transmission part, the servo transmission part comprises a machine shell, a servo motor arranged on the machine shell, a ball screw rotationally connected into the machine shell and parallel to the output shaft of the servo motor, and a transmission belt connected between the servo motor and the front end of the ball screw. An output shaft of the servo motor is located in the machine shell. The hydraulic cylinder part comprises a cylinder body fixed to the machine shell and arranged at the rear end of the ball screw in a sleeving mode, a piston connected into the cylinder body in a sliding mode in the axial direction of the ball screw, a piston rod coaxially and fixedly connected with the ball screw, and an auxiliary spring arranged on the piston rod and the ball screw in a sleeving mode and located between the front end of the cylinder body and the piston. The device can accurately control the stroke of the piston of the hydraulic cylinder, is not interfered by temperature, and realizes high-flow output within a specified temperature range. Meanwhile, the response speed is high, delay is low, and therefore the development period of the air suspension is shortened.

Description

Technical Field

[0001] The utility model belongs to the field of air spring accessories, and particularly relates to a hydraulic device for precise oil supply. Background Art

[0002] With the continuous development of the machinery industry, currently, hydraulic control is generally adopted for automotive suspension systems on the market, and oil pumps are generally used as power devices in hydraulic systems. The oil pump sucks oil from the fuel tank and discharges high-pressure oil from the oil outlet into the hydraulic system to provide power for the hydraulic system. This system has the disadvantage of low position control accuracy and increasingly cannot meet the existing experimental requirements of high precision and large load-bearing capacity, forcing the development of a hydraulic device that meets the requirements to be the top priority at present. In the current hydraulic device, there is pressure pulsation when outputting oil, which will cause the load to fluctuate accordingly. Affected by temperature, oil absorption is blocked at low temperatures, and large-flow output cannot be achieved. At the same time, due to the internal leakage of the pump, on the one hand, it is difficult to accurately control the output flow rate; on the other hand, there is efficiency loss, and some energy is wasted due to the volumetric efficiency of the pump. There are also problems such as slow response speed, relatively high delay, and non-fixed delay time. Summary of the Invention

[0003] The purpose of the utility model is to provide a hydraulic device for precise oil supply, which combines a hydraulic cylinder part and a servo drive part, so that the device has both high precision and large load-bearing capacity at the same time.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme: A hydraulic device for precise oil supply, which includes a hydraulic cylinder part and a servo drive part. The servo drive part includes a machine shell, a servo motor arranged on the machine shell with its output shaft located inside the machine shell, a ball screw rotatably connected inside the machine shell and arranged parallel to the output shaft of the servo motor, and a transmission belt connected between the front end parts of the servo motor and the ball screw; the hydraulic cylinder part includes a cylinder body fixed on the machine shell and sleeved on the rear end part of the ball screw, a piston slidably connected along the axial direction of the ball screw inside the cylinder body, a piston rod coaxially and fixedly connected with the ball screw, and an assisting spring sleeved on the piston rod and the ball screw and located between the front end part of the cylinder body and the piston.

[0005] Another implementation manner is that the front end part of the cylinder body is an installation base, and the assisting spring is compressed between the installation base and the piston.

[0006] Another implementation manner is that an oil injection port is arranged on the side wall of the rear end part of the cylinder body, and an oil outlet is arranged on the end face of the rear end part. The oil outlet is communicated with the bladder of the air suspension.

[0007] Another implementation manner is that the device includes a pump station for supplying oil to the hydraulic cylinder part.

[0008] Another implementation mode is that the device includes an electric control unit that coordinates the actions of a control pump station, a hydraulic cylinder unit, and a servo drive unit.

[0009] Another implementation mode is that the ball screw includes a profile housing fixedly connected to the machine housing, a screw rod rotatably connected inside the profile housing, a nut threadedly connected to the screw rod, the piston rod is fixedly inserted into the front end of the nut, a guide block is provided on the circumferential surface of the nut, a guide groove extending along the axial direction of the screw rod is formed inside the profile housing, and the guide block is slidably connected to the guide groove. When the screw rod rotates, the nut is pushed by the screw rod and moves axially, thereby driving the piston rod and the piston to move up and down.

[0010] Another implementation mode is that a first installation groove and a second installation groove are formed on the lower end surface of the piston. The first installation groove is located at the center of the piston, and the second installation groove is annular and located on the outer circumference of the first installation groove.

[0011] Another implementation mode is that the boosting spring is sleeved on the nut and the piston rod, and the upper end is located inside the second installation groove.

[0012] Another implementation mode is that the upper end of the piston rod is threadedly connected to the first installation groove, and when it reaches the upper limit position, there is a gap between its upper end surface and the first installation groove. The gap is filled with a pressure medium to prevent the upper end of the piston rod from colliding rigidly with the piston when the piston rod and the piston are stripped of threads and the upper end of the piston rod moves upward.

[0013] The beneficial effects of the present utility model are as follows: The device can accurately control the piston stroke of the hydraulic cylinder, is not interfered by temperature, and can achieve large-flow output within a specified temperature range. The flow output is stable, and at the same time, the response speed is fast and the delay is low, thereby saving the development cycle of the air suspension. Description of the Drawings

[0014] Figure 1 is a side view of the present utility model;

[0015] Figure 2 is Figure 2 sectional view A-A of

[0016] Figure 3 is a front view of the present utility model;

[0017] Figure 4 is Figure 3 sectional view B-B of Detailed Implementation Modes

[0018] The following provides a detailed description of the present utility model in conjunction with the embodiments shown in the drawings:

[0019] As Figures 1-4 shown, a precise fuel supply hydraulic device includes a hydraulic cylinder part, a servo drive part, a pump station for supplying oil to the hydraulic cylinder part, and an electric control part for controlling the coordinated operation of the pump station, the hydraulic cylinder part, and the servo drive part. The pump station and the electric control part are prior arts and will not be elaborated here.

[0020] Specifically, the servo drive part includes a housing 130, a servo motor 140 provided on the housing with an output shaft located inside the housing, a ball screw 160 rotatably connected inside the housing 130 and arranged parallel to the output shaft of the servo motor 140, and a drive belt 150 connected between the front ends of the servo motor and the ball screw; the hydraulic cylinder part includes a cylinder block 60 fixed on the housing and sleeved on the rear end of the ball screw, a piston 90 slidably connected along the axial direction of the ball screw inside the cylinder block, a piston rod 110 coaxially and fixedly connected to the ball screw, a booster spring 100 sleeved on the piston rod and the ball screw and located between the front end of the cylinder block and the piston, a second sealing ring 40 provided on the outer peripheral surface of the piston 90, and a first sealing ring 30 provided on the mounting seat 20 of the cylinder block for sealing the gap between the mounting seat 20 and the cylinder block. The front end of the cylinder block is a mounting base 120, and the booster spring is compressed between the mounting base and the piston. An oil injection port 70 is provided on the side wall of the rear end of the cylinder block, and an oil outlet 80 is provided on the end face of the rear end. The oil outlet is communicated with the bladder of the air suspension.

[0021] The ball screw includes a profile housing 1 fixedly connected to the machine housing, a screw rod 2 rotatably connected within the profile housing 1, and a nut 3 threadedly connected to the screw rod 2. The upper end of the profile housing 1 is fixedly and sealingly connected to the lower end surface of the mounting base 120. The piston rod 110 is fixedly inserted into the front end of the nut 3. A guide block 4 is provided on the circumferential surface of the nut 3. A guide groove 5 extending along the axial direction of the screw rod 2 is formed inside the profile housing 1. The guide block 4 is slidably connected within the guide groove 5. When the screw rod 2 rotates, the nut 3 is pushed by the screw rod 2 and moves axially, thereby driving the piston rod 110 and the piston to move up and down. A first metal sealing slip ring 6 that is slidable and rotatable with the screw rod 2 is sleeved on the lower end of the screw rod 2. The first metal sealing slip ring 6 is fixedly connected within the machine housing 130. A slidable second metal sealing slip ring 7 is sleeved on the lower end of the nut 3. The second metal sealing slip ring 7 is fixedly connected within the profile housing 1. A first mounting groove 8 and a second mounting groove 9 are formed on the lower end surface of the piston. The first mounting groove is located at the center of the piston 90. The second mounting groove 9 is annular and is located on the outer circumference of the first mounting groove 8. The boosting spring 100 is sleeved on the nut 3 and the piston rod 110, and its upper end is located within the second mounting groove 9. The upper end of the piston rod 110 is threadedly connected within the first mounting groove 8. When it reaches the upper limit position, there is a gap C between its upper end surface and the first mounting groove 8. The gap C is filled with a pressure medium to prevent the upper end of the piston rod 110 from colliding rigidly with the piston when the piston rod 110 and the piston are stripped of threads.

[0022] The operations of each part of this device are as follows:

[0023] First: Install and fix the air spring on the corresponding equipment. The electronic control unit controls the hydraulic oil in the pump station to be injected into the cylinder block 60 through the oil injection port 70. The oil outlet 80 is connected to the air suspension bladder.

[0024] Second: The electronic control unit controls the servo drive unit. After the servo drive unit reaches the limit position, it stops moving. During this process, the hydraulic oil continues to be injected through the oil injection port 70.

[0025] Third: During the continuous injection of the hydraulic oil, the data acquisition and processing system determines whether to continue injecting oil based on the pressure change. After reaching the set value, the oil supply is stopped, and then the oil injection port 70 is tightened.

[0026] Fourth: After the hydraulic oil injection is completed and the oil injection port 70 is tightened, the hydraulic device now serves as the hydraulic power source for the air spring and precisely realizes the function of injecting oil into the air suspension by moving up and down through the servo drive unit. The hydraulic cylinder part 100 can effectively increase the bearing capacity and quickly return to position during the up and down movement of the piston rod 110.

[0027] Fifth: The hydraulic cylinder part consists of a cylinder block 60, a piston rod 110, a piston 90, a booster spring 100, a sealing ring 30, a sealing ring 40, a mounting seat 20 and bolts 10. The servo system is connected to the hydraulic cylinder through a flange and is sealed through the sealing ring.

[0028] Sixth: Through the drive belt 150 and the ball screw 160, the servo motor converts the output rotational speed and torque into speed and force, which act on the piston rod 110 of the hydraulic cylinder. The piston rod 110 drives the piston 90 to move, changing the volume of the rodless cavity and controlling the discharge and suction of hydraulic oil. By adjusting the rotational speed and torque of the servo motor 140, the displacement and force of the piston 90 of the hydraulic cylinder can be precisely controlled. Inside the hydraulic cylinder cavity, the booster spring 100 is connected to the piston 90. By setting a certain compression amount, a certain pre-tightening force can be generated to assist the hydraulic piston to push quickly, thereby improving the response speed of the system.

[0029] The above embodiments are only used to illustrate the technical concept and features of the present invention, and the purpose is to enable those familiar with this technology to understand the content of the present invention and implement it accordingly. It should not be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A hydraulic device for accurately supplying oil, comprising a hydraulic cylinder part and a servo transmission part, characterized in that: The servo transmission part includes a casing, a servo motor arranged on the casing and with its output shaft located in the casing, a ball screw rotatably connected to the casing and arranged parallel to the output shaft of the servo motor, and a transmission belt connected between the servo motor and the front end of the ball screw; the hydraulic cylinder part includes a cylinder body fixed to the casing and sleeved on the rear end of the ball screw, a piston slidably connected to the cylinder body along the axial direction of the ball screw, a piston rod coaxially fixedly connected to the ball screw, and a booster spring sleeved on the piston rod and the ball screw and located between the front end of the cylinder body and the piston.

2. The precise oil supply hydraulic device according to claim 1, characterized in that: The front end of the cylinder body is a mounting base, and the booster spring is compressed between the mounting base and the piston.

3. The precise oil supply hydraulic device according to claim 1, characterized in that: An oil filling port is arranged on the side wall of the rear end portion of the cylinder body, and an oil outlet is arranged on the end surface of the rear end portion. The oil outlet is communicated with the bladder skin of the air suspension.

4. The precise oil supply hydraulic device according to claim 1, characterized in that: The device comprises a pump station for supplying oil to the hydraulic cylinder part.

5. The precise oil supply hydraulic device according to claim 4, characterized in that: The device comprises an electronic control unit for controlling the coordinated actions of a pump station, a hydraulic cylinder unit and a servo transmission unit.

6. The precise oil supply hydraulic device according to claim 1, characterized in that: The ball screw includes a profile shell fixedly connected to the casing, a screw rotatably connected to the profile shell, and a nut threadedly connected to the screw. The piston rod is fixedly inserted at the front end of the nut, and a guide block is provided on the circumferential surface of the nut. A guide groove extending along the axial direction of the screw is formed inside the profile shell, and the guide block is slidably connected to the guide groove. When the screw rotates, the nut is pushed by the screw and moves along its axial direction, thereby driving the piston rod and the piston to move up and down.

7. The precise oil supply hydraulic device according to claim 6, characterized in that: A first mounting groove and a second mounting groove are formed on the lower end surface of the piston. The first mounting groove is located at the center of the piston, and the second mounting groove is annular and located at the periphery of the first mounting groove.

8. The precise oil supply hydraulic device according to claim 7, characterized in that: The booster spring is sleeved on the nut and the piston rod, and the upper end portion is located in the second mounting groove.

9. The precise oil supply hydraulic device according to claim 7, characterized in that: The upper end portion of the piston rod is threadedly connected to the first mounting groove, and when it reaches the upper limit position, there is a gap between its upper end surface and the first mounting groove, and the gap is filled with pressure medium.

Images