A multi-cylinder lifting / lowering synchronous digital hydraulic control system

Abstract

The present invention discloses a multi-cylinder lifting / lowering synchronous digital hydraulic control system, including a computer control unit, a lifting cylinder, a displacement sensor, a hydraulically controlled one-way valve, an electric hydraulic reversing valve, and a two-position four-way solenoid valve. The displacement sensor is installed on the lifting cylinder, the electric hydraulic reversing valve is connected to the hydraulically controlled one-way valve, and the hydraulically controlled one-way valve is connected to the bottom end of the lifting cylinder; the electric hydraulic reversing valve is connected to the top end of the lifting cylinder; the two-position four-way solenoid valve is connected to the hydraulically controlled one-way valve; the displacement sensor, the electric hydraulic reversing valve, and the two-position four-way solenoid valve are all electrically connected to the computer control unit. The present invention has a simple structure, can realize high-precision lifting / lowering synchronous control under different load conditions on multiple parallel cylinders, and can also realize that each cylinder works independently. The present invention reduces the system hardware cost, greatly reduces the manual debugging time, reduces the debugging cost, and facilitates the repair and maintenance of the host.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic control systems, and more specifically relates to a multi-cylinder lifting / lowering synchronous digital hydraulic control system. Background Art

[0002] With the development of the machinery manufacturing industry, the application field of hydraulic synchronous drive control technology is becoming wider and wider. Whether it is metal processing machinery, engineering machinery, or aerospace equipment, the requirements for hydraulic synchronous drive control accuracy are getting higher and higher. Hydraulic synchronous drive control is not only simple in structure and convenient in composition, but also easier to achieve high-power control and automatic control of hydraulic equipment. In industry, it is often used for synchronous drive and workbench balance control of large and medium-sized precision stamping hydraulic presses and various large equipment platforms. How to achieve high control accuracy, fast response speed, and reliable control performance of hydraulic presses has become the key to hydraulic system design.

[0003] Therefore, how to provide a multi-cylinder lifting / lowering synchronous digital hydraulic control system has become a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0004] In view of this, the present invention provides a multi-cylinder lifting / lowering synchronous digital hydraulic control system with a simple structure, which can realize high-precision synchronous control of multiple parallel cylinders, and has high lifting and lowering speed and position synchronization accuracy, which greatly reduces manual debugging time and reduces debugging costs and is lower than traditional hydraulic technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A multi-cylinder lifting / lowering synchronous digital hydraulic control system comprises: a computer control unit, a lifting cylinder, a displacement sensor, a hydraulically controlled one-way valve, an electric hydraulic reversing valve, and a two-position four-way solenoid valve, wherein the displacement sensor is installed on the lifting cylinder, the electric hydraulic reversing valve is connected to the forward direction of the hydraulically controlled one-way valve through pipeline one, and the reverse direction of the hydraulically controlled one-way valve is connected to the bottom end of the lifting cylinder through pipeline one; the electric hydraulic reversing valve is connected to the top end of the lifting cylinder through pipeline two; the two-position four-way solenoid valve is connected to the hydraulically controlled one-way valve through pipeline three; the displacement sensor, the electric hydraulic reversing valve and the two-position four-way solenoid valve are all electrically connected to the computer control unit.

[0007] Furthermore, the lifting cylinder, the displacement sensor, the hydraulically controlled one-way valve and the electric hydraulic reversing valve are all provided in plurality and controlled one by one. The plurality of lifting cylinders are designed in parallel, and the hydraulic control system of the present invention can realize high-precision synchronous control of the plurality of lifting cylinders.

[0008] Furthermore, the electric hydraulic reversing valve is connected to a first oil inlet pipeline and a first oil return pipeline. The hydraulic oil enters the lifting cylinder from the first oil inlet pipeline to provide hydraulic power for the lifting cylinder and forms a circulation loop with the first oil return pipeline to achieve cylinder lifting.

[0009] Furthermore, the two-position four-way solenoid valve is connected to a second oil inlet pipeline and a second oil return pipeline. The hydraulic oil enters the two-position four-way solenoid valve from the second oil inlet pipeline and then enters the hydraulically controlled one-way valve to provide opening power for the hydraulically controlled one-way valve to achieve the lowering of the oil cylinder.

[0010] Furthermore, it also includes a relief valve, which is connected between the two-position four-way solenoid valve and the second oil return pipeline. The hydraulic oil entering the two-position four-way solenoid valve also passes through the relief valve and enters the second oil return pipeline to form a circulation loop with the second oil inlet pipeline, so as to control the hydraulic control one-way valve to maintain pressure and keep the hydraulic control one-way valve open all the time.

[0011] Furthermore, it also includes an integrated valve block, on which the hydraulically controlled one-way valve, the two-position four-way solenoid valve, the overflow valve and the electric hydraulic reversing valve are all assembled. The arrangement of the integrated valve block is not only conducive to the installation of the hydraulically controlled one-way valve, the two-position four-way solenoid valve, the overflow valve and the electric hydraulic reversing valve, but also realizes the centralized arrangement of the hydraulically controlled one-way valve, the two-position four-way solenoid valve, the overflow valve and the electric hydraulic reversing valve, thereby reducing the occupied volume.

[0012] Furthermore, the lifting cylinder is connected to the oil port of the integrated valve block through a connecting pipe, thereby achieving more flexible installation and fixation of the lifting cylinder.

[0013] Furthermore, it also includes a control button, which is divided into a synchronous control button and a one-to-one corresponding cylinder control button. The synchronous control button is electrically connected to the computer control unit. By pressing the control button, automatic control of the synchronous lifting / lowering of multiple cylinders can be achieved.

[0014] Furthermore, the synchronous control button includes a lifting button, a stop button and a lowering button. Pressing the lifting button can realize the synchronous lifting of the lifting cylinder; pressing the lowering button can realize the synchronous lowering of the lifting cylinder; pressing the stop button will cause the lifting cylinder to stop moving synchronously.

[0015] Furthermore, the one-to-one corresponding cylinder control buttons respectively realize independent lifting, stopping and lowering for each lifting cylinder. When lifting button 1 is pressed, only the corresponding cylinder is lifted; when lowering button 1 is pressed, only the corresponding cylinder is lowered; when stop button 1 is pressed, only the corresponding cylinder is stopped.

[0016] The beneficial effects of the present invention are:

[0017] The present invention can realize synchronous control of the lifting cylinder through a computer control unit, a displacement sensor, a hydraulically controlled one-way valve, an electric hydraulic reversing valve and a two-position four-way solenoid valve. The lifting and lowering speeds and the position synchronization have high precision, which greatly reduces the manual debugging time, reduces the debugging cost, reduces the traditional hydraulic control cost, and is more convenient for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0019] Figure 1 The accompanying drawing is a control principle diagram of the present invention.

[0020] Figure 2 The accompanying drawing is a schematic structural diagram of the present invention.

[0021] Among them, in the figure,

[0022] 1-displacement sensor; 2-lifting cylinder; 3-hydraulic one-way valve; 4-integrated valve block; 5-two-position four-way solenoid valve; 6-overflow valve; 7-electric hydraulic reversing valve; 8-computer control unit; 9-control button; 10-pipeline one; 11-pipeline two; 12-pipeline three; 13-first oil inlet pipeline; 14-first oil return pipeline; 15-second oil inlet pipeline; 16-second oil return pipeline. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Please see attached Figure 1-2The present invention provides a multi-cylinder lifting / lowering synchronous digital hydraulic control system, comprising: a computer control unit 8, a lifting cylinder 2, a displacement sensor 1, a hydraulically controlled one-way valve 3, an electric hydraulic reversing valve 7, and a two-position four-way solenoid valve 5, wherein the displacement sensor 1 is installed on the lifting cylinder 2, the electric hydraulic reversing valve 7 is connected to the forward direction of the hydraulically controlled one-way valve 3 through a pipeline 10, and the reverse direction of the hydraulically controlled one-way valve 3 is connected to the bottom end of the lifting cylinder 2 through a pipeline 10, and the hydraulically controlled one-way valve 3 can keep each loaded lifting cylinder 2 in a fixed position; the electric hydraulic reversing valve 7 is connected to the top end of the lifting cylinder 2 through a pipeline 2 11; the two-position four-way solenoid valve 5 is connected to the hydraulically controlled one-way valve 3 through a pipeline 3 12; the displacement sensor 1, the electric hydraulic reversing valve 7 and the two-position four-way solenoid valve 5 are all electrically connected to the computer control unit 8.

[0025] There are multiple lifting cylinders 2, displacement sensors 1, hydraulically controlled one-way valves 3 and electric hydraulic reversing valves 7, and they are controlled one by one. Multiple lifting cylinders 2 are designed in parallel, and the loads controlled on each lifting cylinder 2 can be different. The hydraulic control system of the present invention can achieve high-precision synchronous control of multiple lifting cylinders 2.

[0026] In order to further optimize the above technical solution, four lifting cylinders 2, four displacement sensors 1, four hydraulically controlled one-way valves 3 and four electric hydraulic reversing valves 7 are provided.

[0027] The electric hydraulic reversing valve 7 is connected to a first oil inlet pipeline 13 and a first oil return pipeline 14. The hydraulic oil enters the lifting cylinder 2 from the first oil inlet pipeline 13 to provide hydraulic power for the lifting cylinder 2, and forms a circulation loop with the first oil return pipeline 14.

[0028] The two-position four-way solenoid valve 5 is connected to a second oil inlet pipeline 15 and a second oil return pipeline 16. The hydraulic oil enters the two-position four-way solenoid valve 5 from the second oil inlet pipeline 15, and then enters the hydraulically controlled one-way valve 3, providing opening power for the hydraulically controlled one-way valve 3.

[0029] One end of the first oil inlet pipeline 13 and the second oil inlet pipeline 15 are both connected to the hydraulic pump.

[0030] The present invention further includes a relief valve 6, which is connected between the two-position four-way solenoid valve 5 and the second oil return pipeline 16. The hydraulic oil entering the two-position four-way solenoid valve 5 also passes through the relief valve 6 and enters the second oil return pipeline 16, forming a circulation loop with the second oil inlet pipeline 15, providing the hydraulic control check valve 3 with a pressure to keep it open.

[0031] The present invention further comprises an integrated valve block 4, on which the hydraulically controlled one-way valve 3, the two-position four-way solenoid valve 5, the overflow valve 6 and the electric hydraulic reversing valve 7 are all assembled. The arrangement of the integrated valve block 4 is not only conducive to the installation of the hydraulically controlled one-way valve 3, the two-position four-way solenoid valve 5, the overflow valve 6 and the electric hydraulic reversing valve 7, but also realizes the centralized arrangement of the hydraulically controlled one-way valve 3, the two-position four-way solenoid valve 5, the overflow valve 6 and the electric hydraulic reversing valve 7, thereby reducing the occupied volume.

[0032] In order to further optimize the above technical solution, the lifting cylinder 2 is connected to the oil port of the integrated valve block 4 through a connecting pipe, thereby achieving the flexibility of installation and fixing of the lifting cylinder 2.

[0033] The present invention also includes a control button 9, which is divided into a synchronous control button and a one-to-one corresponding cylinder control button. The synchronous control button is electrically connected to the computer control unit 8. By pressing the synchronous control button, automatic control of the synchronous lifting / lowering of multiple cylinders can be achieved.

[0034] In order to further optimize the above technical solution, the synchronous control button includes a lifting button, a stop button and a lowering button. Pressing the lifting button can realize the synchronous lifting of the lifting cylinder 2; pressing the lowering button can realize the synchronous lowering of the lifting cylinder 2; pressing the stop button will cause the lifting cylinder 2 to stop moving synchronously.

[0035] In order to further optimize the above technical solution, one-to-one corresponding cylinder control buttons respectively realize independent lifting, stopping and lowering for each lifting cylinder 2. When lifting button 1 is pressed, only the corresponding cylinder is lifted; when lowering button 1 is pressed, only the corresponding cylinder is lowered; when stop button 1 is pressed, only the corresponding cylinder is stopped.

[0036] The present invention can realize synchronous control of the lifting cylinder 2 through the computer control unit 8, displacement sensor 1, hydraulic control one-way valve 3, electric hydraulic reversing valve 7 and two-position four-way solenoid valve 5, and the lifting and lowering speed and position synchronization accuracy are high, which greatly reduces the manual debugging time, reduces the debugging cost, reduces the traditional hydraulic control cost, and is more convenient for maintenance. In addition, the present invention also has fault alarm, fault storage, and display of fault code. The present invention can also realize remote control, and the computer control unit 8 is connected to the mobile Internet to realize the functions of mobile Internet control and operation, mobile Internet fault diagnosis, etc.

[0037] Working principle of the present invention:

[0038] When the lifting button is pressed, an electrical signal is sent to the computer control unit 8, and the computer control unit 8 sends instructions to each electric hydraulic reversing valve 7. The electric hydraulic reversing valve 7 opens a fixed valve opening synchronously according to the control instructions of the computer control unit 8. The pressure oil enters the bottom chamber of the lifting cylinder 2 through the pipeline 10 and flows out from the pipeline 2 11. The lifting cylinder 2 starts the lifting movement. During the lifting process, the displacement sensor 1 detects the speed and position of the lifting cylinder 2, and feeds the detected parameters back to the computer control unit 8 for PID calculation to calculate the average speed and average position point. When a certain lifting cylinder 2 is less than or greater than the average speed, the computer control unit 8 adjusts the valve port of the electric hydraulic reversing valve 7 of this lifting cylinder 2 so that the actual operating speed of the lifting cylinder 2 is equal to the average speed, so that multiple cylinders lift at the same speed, that is, speed synchronization (in this case, four cylinders lift synchronously). When the position point of a certain lifting cylinder 2 is greater than or less than the average position point, the computer control unit 8 adjusts the valve port of the electric hydraulic reversing valve 7 of this lifting cylinder 2, and instantly changes the speed of each lifting cylinder 2, so that the lifting cylinder 2 can achieve multi-cylinder position point synchronization, that is, position synchronization, within the next three test times.

[0039] When the descending button is pressed, the two-position four-way solenoid valve 5 is energized, so that the pressure oil enters from the second oil inlet pipe to open the hydraulically controlled one-way valve 3, and an electrical signal is sent to the computer control unit 8. The computer control unit 8 sends instructions to each electric hydraulic reversing valve 7 to make the electric hydraulic reversing valve 7 switch the direction of the inlet and outlet oil, and the electric hydraulic reversing valve 7 controls the instructions of the computer control unit 8 so that each electric hydraulic reversing valve 7 opens a fixed valve opening synchronously. The pressure oil enters the top of the lifting cylinder 2 from the pipeline 2 11 and flows out from the pipeline 1 10. The lifting cylinder 2 starts to move downward. The lifting cylinder 2 is synchronized during the descending process. The displacement sensor 1 detects the speed and position of the lifting cylinder 2, and feeds the detected parameters back to the computer control unit 8 for PID calculation to calculate the average speed and average position point. When a certain lifting cylinder 2 is less than or greater than the average speed, the computer control unit 8 adjusts the valve port of the electric hydraulic reversing valve 7 of the lifting cylinder 2 so that the actual operating speed of the lifting cylinder 2 is equal to the average speed, so that multiple cylinders lift at the same speed, that is, speed synchronization (in this case, four cylinders lift synchronously). When the position point of a certain lifting cylinder 2 is greater than or less than the average position point, the computer control unit 8 adjusts the valve port of the electric hydraulic reversing valve 7 of the lifting cylinder 2, instantly changes the speed of each lifting cylinder 2, so that the lifting cylinder 2 reaches the synchronization of multiple cylinder position points, that is, position synchronization, within the next 3 test times.

[0040] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0041] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-cylinder lifting / lowering synchronous digital hydraulic control method, characterized in that: include: A computer control unit (8), a lifting cylinder (2), a displacement sensor (1), a hydraulically controlled one-way valve (3), an electric hydraulic reversing valve (7), and a two-position four-way solenoid valve (5), wherein the displacement sensor (1) is mounted on the lifting cylinder (2); the electric hydraulic reversing valve (7) is connected to the forward direction of the hydraulically controlled one-way valve (3) through a pipeline one (10); the reverse direction of the hydraulically controlled one-way valve (3) is connected to the bottom end of the lifting cylinder (2) through the pipeline one (10); the electric hydraulic reversing valve (7) is connected to the top end of the lifting cylinder (2) through a pipeline two (11); the two-position four-way solenoid valve (5) is connected to the hydraulically controlled one-way valve (3) through a pipeline three (12); the displacement sensor (1), the electric hydraulic reversing valve (7) and the two-position four-way solenoid valve (5) are all electrically connected to the computer control unit (8); The lifting cylinder (2), the displacement sensor (1), the hydraulically controlled one-way valve (3) and the electric hydraulic reversing valve (7) are each provided in plurality and arranged in one-to-one correspondence, and the plurality of lifting cylinders (2) are designed in parallel; It also includes a control button (9), the control button (9) is divided into a synchronization control button and a one-to-one corresponding cylinder control button, the synchronization control button is electrically connected to the computer control unit (8), and pressing the synchronization control button can realize automatic control of the synchronous lifting / lowering of multiple cylinders; The synchronous control buttons include a lifting button, a stop button and a lowering button; by pressing the lifting button, the lifting cylinder (2) can be raised synchronously; by pressing the lowering button, the lifting cylinder (2) can be lowered synchronously; When the stop button is pressed, the lifting cylinder (2) stops moving synchronously; When the lifting button is pressed, an electrical signal is sent to the computer control unit (8), and the computer control unit (8) sends a command to each electric hydraulic reversing valve (7). The electric hydraulic reversing valve (7) opens a fixed valve opening synchronously according to the control command of the computer control unit (8). The pressure oil enters the bottom chamber of the lifting cylinder (2) through the pipeline 1 (10) and flows out from the pipeline 2 (11). The lifting cylinder (2) starts the lifting movement. During the lifting process of the lifting cylinder (2), the displacement sensor (1) detects the speed and position of the lifting cylinder (2), and feeds back the detected parameters to the computer control unit (8) for PID calculation to calculate the average speed. and average position point. When the speed of a certain lifting cylinder (2) is less than or greater than the average speed, the computer control unit (8) adjusts the valve port of the electric hydraulic reversing valve (7) of the lifting cylinder (2) so that the actual operating speed of the lifting cylinder (2) is equal to the average speed, so that multiple cylinders can lift at the same speed, that is, speed synchronization. When the position point of a certain lifting cylinder (2) is greater than or less than the average position point, the computer control unit (8) adjusts the valve port of the electric hydraulic reversing valve (7) of the lifting cylinder (2) so as to instantly change the speed of each lifting cylinder (2) so that the lifting cylinder (2) can achieve the synchronization of the position points of multiple cylinders, that is, position synchronization, within the next three test times.

2. A multi-cylinder lifting / lowering synchronous digital hydraulic control method according to claim 1, characterized in that: The electric hydraulic reversing valve (7) is connected to a first oil inlet pipeline (13) and a first oil return pipeline (14).

3. A multi-cylinder lifting / lowering synchronous digital hydraulic control method according to claim 1 or 2, characterized in that: The two-position four-way solenoid valve (5) is connected to a second oil inlet pipeline (15) and a second oil return pipeline (16).

4. A multi-cylinder lifting / lowering synchronous digital hydraulic control method according to claim 3, characterized in that: It also includes a relief valve (6), which is connected between the two-position four-way solenoid valve (5) and the second oil return pipeline (16).

5. A multi-cylinder lifting / lowering synchronous digital hydraulic control method according to claim 4, characterized in that: It also comprises an integrated valve block (4), on which the hydraulically controlled one-way valve (3), the two-position four-way solenoid valve (5), the overflow valve (6) and the electric hydraulic reversing valve (7) are all assembled.

6. A multi-cylinder lifting / lowering synchronous digital hydraulic control method according to claim 5, characterized in that: The lifting oil cylinder (2) is connected to the integrated valve block (4) via a connecting pipe.

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