Hydraulic cylinder pressure control system and method of controlling the same

Abstract

The application provides a hydraulic cylinder pressure control system and a control method thereof. The hydraulic cylinder pressure control system comprises a controller, an electromagnetic driver, a plurality of hydraulic cylinder groups, each hydraulic cylinder group comprising a reversing valve, a first electrically-controlled check valve, a second electrically-controlled check valve, a first oil pressure sensor, a second oil pressure sensor and a hydraulic cylinder; a left cavity of the hydraulic cylinder, the first oil pressure sensor, the first electrically-controlled check valve and the reversing valve are sequentially connected; a right cavity of the hydraulic cylinder, the second oil pressure sensor, the second electrically-controlled check valve and the reversing valve are sequentially connected; the reversing valve is connected with a main pump end and a hydraulic oil tank end respectively; the controller is connected with the electromagnetic driver, the first oil pressure sensor and the second oil pressure sensor respectively; and the electromagnetic driver is connected with the first electrically-controlled check valve, the second electrically-controlled check valve and the reversing valve respectively. The hydraulic cylinder pressure control system can reduce the cost and the failure rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of hydraulic cylinder, in particular to a hydraulic cylinder pressure control system and a control method thereof. BACKGROUND

[0002] Hydraulic cylinder is a key output element in hydraulic system. It converts hydraulic energy into mechanical energy output, and drives various mechanical joints and applies load. The control of hydraulic cylinder output force has been a long-term research point in the hydraulic industry. At present, one type of hydraulic cylinder pressure proportional control adopted in the industry is proportional pressure valve, and the other type is high-performance servo valve. The disadvantages of the two types are high cost, easy to be blocked by oil pollutants, high failure rate and difficult to manufacture. SUMMARY

[0003] In order to solve at least one technical problem in the prior art, the present application provides a hydraulic cylinder pressure control system and a control method thereof.

[0004] In a first aspect of the present application, a hydraulic cylinder pressure control system is provided, comprising: a controller, an electromagnetic driver, a plurality of hydraulic cylinder groups, each of the hydraulic cylinder groups comprising a reversing valve, a first electrically controlled check valve, a second electrically controlled check valve, a first oil pressure sensor, a second oil pressure sensor and a hydraulic cylinder;

[0005] The left cavity of the hydraulic cylinder, the first oil pressure sensor, the first electrically controlled check valve and the reversing valve are connected in sequence;

[0006] The right cavity of the hydraulic cylinder, the second oil pressure sensor, the second electrically controlled check valve and the reversing valve are connected in sequence;

[0007] The reversing valve is connected to the main pump end and the hydraulic oil tank end respectively, and the controller is connected to the electromagnetic driver, the first oil pressure sensor and the second oil pressure sensor respectively;

[0008] The electromagnetic driver is connected to the first electrically controlled check valve, the second electrically controlled check valve and the reversing valve respectively.

[0009] Optionally, the system comprises a plurality of hydraulic cylinder groups.

[0010] Optionally, the reversing valve is used to switch the direction of hydraulic cylinder movement and cut off each oil port.

[0011] Optionally, the controller comprises:

[0012] The hydraulic cylinder left cavity pressurization control module is used for controlling the left side electromagnetic valve of the reversing valve to be powered on, controlling the first electrically controlled check valve to be powered off, controlling the second electrically controlled check valve to be powered on, and controlling the main pump end to output at a preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor reaching the preset pressurization pressure, the reversing valve is controlled to be powered off and the main pump end is controlled to be depressurized.

[0013] The hydraulic cylinder left cavity depressurization control module is used for controlling the main pump end to output at a preset depressurization pressure, controlling the left side electromagnetic valve of the reversing valve to be powered on, and controlling the first electrically controlled check valve to be powered on; in response to the pressure value detected by the first oil pressure sensor reaching the preset depressurization pressure, the first electrically controlled check valve is controlled to be closed, the reversing valve is controlled to be closed, and the main pump end is controlled to be depressurized in sequence.

[0014] The hydraulic cylinder left cavity pressure maintenance control module is used for controlling the first electrically controlled check valve to be powered off.

[0015] Optionally, the controller comprises:

[0016] The hydraulic cylinder right cavity pressurization control module is used for controlling the right side electromagnetic valve of the reversing valve to be powered on, controlling the second electrically controlled check valve to be powered off, controlling the first electrically controlled check valve to be powered on, and controlling the main pump end to output at a preset pressurization pressure; in response to the pressure value detected by the second oil pressure sensor reaching the preset pressurization pressure, the reversing valve is controlled to be powered off and the main pump end is controlled to be depressurized.

[0017] The hydraulic cylinder right cavity depressurization control module is used for controlling the main pump end to output at a preset depressurization pressure, controlling the right side electromagnetic valve of the reversing valve to be powered on, and controlling the second electrically controlled check valve to be powered on; in response to the pressure value detected by the second oil pressure sensor reaching the preset depressurization pressure, the second electrically controlled check valve is controlled to be closed, the reversing valve is controlled to be closed, and the main pump end is controlled to be depressurized in sequence.

[0018] The hydraulic cylinder right cavity pressure maintenance control module is used for controlling the second electrically controlled check valve to be powered off.

[0019] In a second aspect, the application provides a control method of the hydraulic cylinder pressure control system according to any one of the second aspect of the application, comprising:

[0020] In the hydraulic cylinder left cavity pressurization section, the left side electromagnetic valve of the reversing valve is controlled to be powered on, the first electrically controlled check valve is controlled to be powered off, the second electrically controlled check valve is controlled to be powered on, and the main pump end is controlled to output at a preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor reaching the preset pressurization pressure, the reversing valve is controlled to be powered off and the main pump end is controlled to be depressurized.

[0021] In the left cavity pressure reduction section of the hydraulic cylinder, the main pump end is controlled to output at a preset pressure reduction, the left electromagnetic valve of the reversing valve is controlled to be powered on, and the first electric control check valve is controlled to be powered on; in response to the pressure value detected by the first oil pressure sensor reaching the preset pressure reduction, the first electric control check valve is controlled to be closed, the reversing valve is controlled to be closed, and the main pump end is controlled to be depressurized.

[0022] Optionally, the method further comprises:

[0023] In the left cavity pressure maintaining section of the oil cylinder, the first electric control check valve is controlled to be powered off.

[0024] Optionally, the method further comprises:

[0025] In the right cavity pressure increasing section of the hydraulic cylinder, the right electromagnetic valve of the reversing valve is controlled to be powered on, the second electric control check valve is controlled to be powered off, the first electric control check valve is controlled to be powered on, and the main pump end is controlled to output at a preset pressure increasing; in response to the pressure value detected by the second oil pressure sensor reaching the preset pressure increasing, the reversing valve is controlled to be powered off and the main pump end is controlled to be depressurized.

[0026] Optionally, the method further comprises: in the right cavity pressure reduction section of the hydraulic cylinder, the main pump end is controlled to output at a preset pressure reduction, the right electromagnetic valve of the reversing valve is controlled to be powered on, and the second electric control check valve is controlled to be powered on; in response to the pressure value detected by the second oil pressure sensor reaching the preset pressure reduction, the second electric control check valve is controlled to be closed, the reversing valve is controlled to be closed, and the main pump end is controlled to be depressurized.

[0027] Optionally, the method further comprises: in the right cavity pressure maintaining section of the oil cylinder, the second electric control check valve is controlled to be powered off.

[0028] One or more technical solutions provided in the embodiments of the present application can achieve the following technical effects:

[0029] 1. The oil pressure control can be realized at low cost, and the cost of the oil pressure control system is reduced.

[0030] 2. Different pressure ratio controls of multiple hydraulic cavity groups can be realized, and the corresponding proportional air pressure mode is simple and the control effect is better.

[0031] 3. The electric control check valve cone valve core has good sealing performance and very small leakage, so the pressure maintaining capacity of the system is better.

[0032] 4. The hydraulic cylinder pressure control system of the present application has simple structure, easy manufacturing and processing, strong anti-pollution ability and low system failure rate. BRIEF DESCRIPTION OF DRAWINGS

[0033] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application.

[0034] Figure 1 A flow chart of a hydraulic cylinder pressure control system according to an exemplary embodiment of the application is shown. DETAILED DESCRIPTION

[0035] Embodiments of the application will be described in greater detail below with reference to the drawings. While several embodiments of the application are shown in the drawings, it is understood that the application can be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the application to those skilled in the art. It is understood that the drawings and the embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the application.

[0036] It should be understood that the various steps of the method embodiments of the application can be performed in different orders and / or in parallel. Furthermore, the method embodiments can include additional steps and / or omit performing the steps shown. The scope of the application is not limited in this respect.

[0037] The term "comprising" and variations thereof as used herein are used inclusively, i.e., "comprising but not limited to." The term "based on" is "based at least in part on." The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments." Related terms are defined in the description that follows. It should be noted that reference herein to "first", "second", etc. concepts merely serves to distinguish different apparatuses, modules, or units, and is not intended to limit the order or interdependence of the functions performed by these apparatuses, modules, or units.

[0038] It should be noted that the terms "a" and "an" and "the" and similar referents used in the context of describing the application are to be construed to cover both singular as well as plural and are used interchangeably with "one or more." Unless otherwise indicated herein, the use of relational terms and / or adjectives, such as "by way of illustration," "exemplary," "example," "e.g.," "among others," "some," and "numerous," are used herein to describe a non-limiting option and / or an implementation thereof.

[0039] The names of the messages or information exchanged between the various apparatuses in the embodiments of the application are used for illustrative purposes only and are not intended to limit the scope of the messages or information.

[0040] The aspects of the application will now be described with reference to the drawings:

[0041] Reference will now be made to Figure 1A hydraulic cylinder pressure control system, comprising: a controller, an electromagnetic driver, a plurality of hydraulic cylinder groups, each hydraulic cylinder group comprising a reversing valve 1, a first electrically controlled check valve 2, a second electrically controlled check valve 3, a first oil pressure sensor 4, a second oil pressure sensor 5, and a hydraulic cylinder 6; the left cavity 601 of the hydraulic cylinder 6, the first oil pressure sensor 4, the first electrically controlled check valve 2, and the reversing valve 1 are connected in sequence; the right cavity 602 of the hydraulic cylinder 6, the second oil pressure sensor 5, the second electrically controlled check valve 3, and the reversing valve 1 are connected in sequence; the reversing valve 1 is connected with the main pump end P and the hydraulic oil tank end T respectively, the controller is connected with the electromagnetic driver, the first oil pressure sensor 4, and the second oil pressure sensor 5 respectively, and is used for receiving the pressure feedback of the first oil pressure sensor 4 and the second oil pressure sensor 5; the electromagnetic driver is connected with the reversing valve 1, the first electrically controlled check valve 2, and the second electrically controlled check valve 3 respectively, and is used for controlling the reversing valve 1, the first electrically controlled check valve 2, and the second electrically controlled check valve 3. Wherein, the reversing valve 1 is used for switching the direction of the hydraulic cylinder 6 and cutting off each oil port, the first electrically controlled check valve 2 and the second electrically controlled check valve 3 are used for one-way flow, and have pressure maintaining function. The first oil pressure sensor 4 and the second oil pressure sensor 5 are used for detecting and feeding back the hydraulic pressure of the left and right cavities of the hydraulic cylinder. The hydraulic cylinder is used as a system output force executing mechanism. The controller controls the electromagnetic driver to drive and control the reversing valve 1, the first electrically controlled check valve 2, and the second electrically controlled check valve 3. The hydraulic cylinder group system in the system can be a plurality of hydraulic cylinder groups, and the number of hydraulic cylinder groups can be designed according to actual needs.

[0042] The hydraulic cylinder pressure control system of the present application can realize the pressure increasing, pressure reducing, and pressure maintaining control of the left and right cavities of the hydraulic cylinder. The pressure increasing, pressure reducing, and pressure maintaining control of the left cavity of the hydraulic cylinder are taken as examples for description:

[0043] The hydraulic cylinder pressure control system provided by the present application can realize the pressure increasing, pressure reducing, and pressure maintaining control of the left and right cavities of the hydraulic cylinder. The pressure increasing, pressure reducing, and pressure maintaining control of the left cavity of the hydraulic cylinder are taken as examples for description:

[0044] The left cavity of the hydraulic cylinder is pressurized:

[0045] The left electromagnetic valve of the reversing valve 1 is powered, and the left station enters the system;

[0046] The first electrically controlled check valve 2 loses power, keeps the original station, and the check valve enters pressure and oil;

[0047] The second electrically controlled one-way valve 3 is powered, the two-way conducting work station enters the system, and is used for oil return pressure relief of the right chamber of the hydraulic cylinder;

[0048] The system main pump end P is pressurized by a preset pressurization pressure; wherein, the actual demand can be set;

[0049] The first oil pressure sensor 4 detects the pressure and feeds back to the controller, and after reaching the preset pressurization pressure, the reversing valve 1 is de-energized to the neutral position, the system main pump end P is depressurized, and the pressure of the left chamber of the hydraulic cylinder is maintained through the first electrically controlled one-way valve 2.

[0050] The left chamber of the hydraulic cylinder is depressurized:

[0051] The system main pump end P is output by a preset depressurization pressure;

[0052] After the pressure output of the system main pump end P is in place, the left electromagnetic valve of the reversing valve 1 is powered, and the left work station enters the system;

[0053] The first electrically controlled one-way valve 2 is powered again through the controller and the electromagnetic driver, and the high pressure of the left chamber of the hydraulic cylinder is matched with the two-stage low pressure output by the system;

[0054] The first oil pressure sensor 4 detects the pressure and feeds back to the controller, and after reaching the preset depressurization pressure, the first electrically controlled one-way valve 2 is closed first to maintain the pressure of the hydraulic cylinder, then the reversing valve 1 is closed to cut off the main system oil circuit, and finally the main system main pump end P is depressurized.

[0055] The left chamber of the hydraulic cylinder is pressure maintained:

[0056] After any pressurization or depressurization is completed, the first electrically controlled one-way valve 2 is de-energized, and the pressure of the left chamber of the hydraulic cylinder is maintained through the electrically controlled one-way valve. Such a spool valve core has excellent sealing performance and excellent pressure maintaining performance. For the case of pressure maintaining for a very long time, the oil pressure sensor can be used for detection feedback, and the pressure value of the preset automatic pressurization is used for pressurization output. That is, in the left chamber of the hydraulic cylinder or in the right chamber of the hydraulic cylinder, the first oil pressure sensor and the second oil pressure sensor can be used to detect the corresponding oil pressure, and if the oil pressure decreases to the target value, the left chamber of the hydraulic cylinder is pressurized.

[0057] The right chamber of the hydraulic cylinder can be pressurized, depressurized and pressure maintained through the same control method as above;

[0058] Other cylinder groups can be pressurized, depressurized and pressure maintained through the same control method as above.

[0059] In one embodiment, the controller includes the following control modules:

[0060] The hydraulic cylinder left cavity pressurization control module is used for controlling the left side electromagnetic valve of the reversing valve 1 to be powered on, controlling the first electric control check valve 2 to be powered off, controlling the second electric control check valve 3 to be powered on, and controlling the main pump end P to output at a preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor 4 reaching the preset pressurization pressure, the reversing valve 1 is controlled to be powered off, and the main pump end P is controlled to be depressurized; the module is used for realizing the control of the hydraulic cylinder left cavity pressurization section.

[0061] The hydraulic cylinder left cavity depressurization control module is used for controlling the main pump end P to output at a preset depressurization pressure, controlling the left side electromagnetic valve of the reversing valve 1 to be powered on, and controlling the first electric control check valve 2 to be powered on; in response to the pressure value detected by the first oil pressure sensor reaching the preset depressurization pressure, the first electric control check valve 2 is controlled to be closed, the reversing valve 1 is controlled to be closed (cut off from the main system oil circuit), and the main pump end P is controlled to be depressurized; the module is used for realizing the control of the hydraulic cylinder left cavity depressurization section. The hydraulic cylinder left cavity depressurization control module is also used for controlling the second electric control check valve 3 to be powered on.

[0062] The hydraulic cylinder left cavity pressure maintenance control module is used for controlling the first electric control check valve 2 to be powered off. The module is used for realizing the control of the hydraulic cylinder left cavity pressure maintenance section.

[0063] The above control modules can be programmed and controlled by a programmable controller, and details are not described again.

[0064] Similarly, the controller can also include the following control modules:

[0065] The hydraulic cylinder right cavity pressurization control module is used for controlling the right side electromagnetic valve of the reversing valve 1 to be powered on, controlling the second electric control check valve 3 to be powered off, controlling the first electric control check valve 2 to be powered on, and controlling the main pump end P to output at a preset pressurization pressure; in response to the pressure value detected by the second oil pressure sensor 5 reaching the preset pressurization pressure, the reversing valve 1 is controlled to be powered off, and the main pump end P is controlled to be depressurized.

[0066] The hydraulic cylinder right cavity depressurization control module is used for controlling the main pump end P to output at a preset depressurization pressure, controlling the right side electromagnetic valve of the reversing valve 1 to be powered on, and controlling the second electric control check valve 3 to be powered on; in response to the pressure value detected by the second oil pressure sensor reaching the preset depressurization pressure, the second electric control check valve 3 is controlled to be closed, the reversing valve 1 is controlled to be closed (cut off from the main system oil circuit), and the main pump end P is controlled to be depressurized; the hydraulic cylinder right cavity depressurization control module is also used for controlling the first electric control check valve 2 to be powered on.

[0067] The hydraulic cylinder right cavity pressure maintenance control module is used for controlling the second electric control check valve 3 to be powered off.

[0068] The application also provides a control method of the hydraulic cylinder pressure control system, comprising:

[0069] S101, in the left chamber of the hydraulic cylinder pressurization section, the left side electromagnetic valve of the reversing valve 1 is powered on, the first electric control check valve 2 is powered off, the second electric control check valve 3 is powered on, and the main pump end P is output according to the preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor 4 reaching the preset pressurization pressure, the reversing valve 1 is powered off and the main pump end P is depressurized.

[0070] S102, in the left chamber of the hydraulic cylinder depressurization section, the main pump end P is output according to the preset depressurization pressure, the left side electromagnetic valve of the reversing valve 1 is powered on, and the first electric control check valve 2 is powered on; in response to the pressure value detected by the first oil pressure sensor reaching the preset depressurization pressure, the first electric control check valve 2 is closed, the reversing valve 1 is closed (cut off from the main system oil circuit), and the main pump end P is depressurized.

[0071] S103, in the left chamber 601 of the hydraulic cylinder pressure maintaining section, the first electric control check valve 2 is powered off.

[0072] In one embodiment, the control method of the hydraulic cylinder pressure control system further comprises:

[0073] S201, in the right chamber of the hydraulic cylinder pressurization section, the right side electromagnetic valve of the reversing valve 1 is powered on, the second electric control check valve 3 is powered off, the first electric control check valve 2 is powered on, and the main pump end P is output according to the preset pressurization pressure; in response to the pressure value detected by the second oil pressure sensor 5 reaching the preset pressurization pressure, the reversing valve 1 is powered off and the main pump end P is depressurized.

[0074] S202, in the right chamber of the hydraulic cylinder depressurization section, the main pump end P is output according to the preset depressurization pressure, the right side electromagnetic valve of the reversing valve 1 is powered on, and the second electric control check valve 3 is powered on; in response to the pressure value detected by the second oil pressure sensor reaching the preset depressurization pressure, the second electric control check valve 3 is closed, the reversing valve 1 is closed (cut off from the main system oil circuit), and the main pump end P is depressurized.

[0075] S203, in the right chamber of the hydraulic cylinder pressure maintaining section, the second electric control check valve 3 is powered off.

[0076] The technical scheme of the application has the following technical effects: based on multiple hydraulic cylinder groups, the proportional pressure control of the hydraulic cylinder is realized; the cost is reduced; the anti-pollution ability is improved; the system failure rate is reduced; the manufacturing and processing difficulty is reduced.

Claims

1. A hydraulic cylinder pressure control system, characterized in that, include: The controller, electromagnetic actuator, and several hydraulic cylinder groups, each of which includes a directional valve (1), a first electrically controlled check valve (2), a second electrically controlled check valve (3), a first oil pressure sensor (4), a second oil pressure sensor (5), and a hydraulic cylinder (6); The left chamber of the hydraulic cylinder (6), the first oil pressure sensor (4), the first electrically controlled check valve (2) and the reversing valve (1) are connected in sequence; The right chamber of the hydraulic cylinder (6), the second oil pressure sensor (5), the second electrically controlled check valve (3) and the reversing valve (1) are connected in sequence; The reversing valve (1) is connected to the main pump end and the hydraulic oil tank end respectively, and the controller is connected to the electromagnetic drive, the first oil pressure sensor (4) and the second oil pressure sensor (5) respectively. The electromagnetic driver is connected to the first electrically controlled check valve (2), the second electrically controlled check valve (3), and the reversing valve (1), respectively. The controller includes: The hydraulic cylinder left chamber pressurization control module is used to control the left solenoid valve of the reversing valve (1) to be energized, control the first electrically controlled check valve (2) to be de-energized, control the second electrically controlled check valve (3) to be energized, and control the main pump end to output according to the preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor (4) reaching the preset pressurization pressure, control the reversing valve (1) to be de-energized and control the main pump end to depressurize; The hydraulic cylinder left chamber pressure reduction control module is used to control the main pump end to output pressure according to the preset pressure reduction, control the left solenoid valve of the reversing valve (1) to be energized, and control the first electrically controlled check valve (2) to be energized; in response to the pressure value detected by the first oil pressure sensor (4) reaching the preset pressure reduction, the first electrically controlled check valve (2) is closed, the reversing valve (1) is closed, and the main pump end is depressurized in sequence; The pressure holding control module for the left chamber of the hydraulic cylinder is used to control the first electrically controlled check valve (2) to lose power; The hydraulic cylinder right chamber pressurization control module is used to control the right solenoid valve of the reversing valve (1) to be energized, control the second solenoid valve (3) to be de-energized, control the first solenoid valve (2) to be energized, and control the main pump end to output according to the preset pressurization pressure; in response to the pressure value detected by the second oil pressure sensor (5) reaching the preset pressurization pressure, the reversing valve (1) is de-energized and the main pump end is depressurized; The hydraulic cylinder right chamber pressure reduction control module is used to control the main pump end to output pressure according to the preset pressure reduction, control the right solenoid valve of the reversing valve (1) to be energized, and control the second electric check valve (3) to be energized; in response to the pressure value detected by the second oil pressure sensor (5) reaching the preset pressure reduction, the second electric check valve (3) is closed, the reversing valve (1) is closed, and the main pump end is depressurized in sequence; The hydraulic cylinder right chamber pressure holding control module is used to control the second electrically controlled check valve (3) to lose power.

2. The system according to claim 1, characterized in that, The system includes multiple sets of the hydraulic cylinder groups.

3. The system according to claim 1, characterized in that, The reversing valve (1) is used to switch the direction of the hydraulic cylinder (6) back and forth movement and to cut off each oil port.

4. A control method for a hydraulic cylinder pressure control system as described in any one of claims 1 to 3, characterized in that, include: In the left chamber pressurization section of the hydraulic cylinder (6), the left solenoid valve of the reversing valve (1) is energized, the first electrically controlled check valve (2) is de-energized, the second electrically controlled check valve (3) is energized, and the main pump outputs pressure according to the preset pressurization pressure; in response to the pressure value detected by the first oil pressure sensor (4) reaching the preset pressurization pressure, the reversing valve (1) is de-energized and the main pump is depressurized. In the pressure reduction section of the left chamber of the hydraulic cylinder (6), the main pump is controlled to output pressure at a preset pressure reduction level, the left solenoid valve of the reversing valve (1) is energized, and the first electrically controlled check valve (2) is energized. In response to the pressure value detected by the first oil pressure sensor (4) reaching the preset pressure reduction level, the first electrically controlled check valve (2), the reversing valve (1), and the main pump are sequentially controlled to close, close, and depressurize.

5. The method according to claim 4, characterized in that, The method further includes: In the pressure-holding section of the left chamber of the oil cylinder, the first electrically controlled check valve (2) is de-energized.

6. The method according to claim 4, characterized in that, The method further includes: In the right chamber pressurization section of the hydraulic cylinder (6), the right solenoid valve of the reversing valve (1) is energized, the second electrically controlled check valve (3) is de-energized, the first electrically controlled check valve (2) is energized, and the main pump is output at the preset pressurization pressure. In response to the pressure value detected by the second oil pressure sensor (5) reaching the preset pressurization pressure, the reversing valve (1) is de-energized and the main pump is depressurized.

7. The method according to claim 4, characterized in that, The method further includes: In the right chamber of the hydraulic cylinder (6), the main pump is controlled to output pressure at a preset pressure reduction level, the right solenoid valve of the reversing valve (1) is energized, and the second electrically controlled check valve (3) is energized. In response to the pressure value detected by the second oil pressure sensor (5) reaching the preset pressure reduction level, the second electrically controlled check valve (3), the reversing valve (1), and the main pump are sequentially controlled to close, close, and depressurize.

8. The method according to claim 4, characterized in that, The method further includes: In the pressure-holding section of the right chamber of the oil cylinder, the second electrically controlled check valve (3) is de-energized.

Images