Deviation rectifying system of hydraulic machine and hydraulic machine

Abstract

The invention provides a deviation rectifying system of a hydraulic machine and the hydraulic machine, and relates to the technical field of hydraulic machines, the deviation rectifying system of the hydraulic machine comprises a first return cylinder, a second return cylinder, a first electromagnetic valve, a first control valve set, a second electromagnetic valve and a second control valve set, the first electromagnetic valve is connected with the first return cylinder and a main working pump, and the second electromagnetic valve is connected with the second return cylinder; the second electromagnetic valve is connected with the second return cylinder and the main working pump, the first end of the first control valve set is connected with an oil port of the first return cylinder, the second end of the first control valve set is used for being connected with an oil tank of the hydraulic machine, and the third end of the first control valve set is used for being connected with a deviation rectifying oil pump of the hydraulic machine. The first end of the second control valve bank is connected with an oil port of the second return cylinder, the second end of the second control valve bank is used for being connected with an oil tank, the third end of the second control valve bank is used for being connected with a deviation rectifying oil pump, and the fourth end of the first control valve bank is connected with the fourth end of the second control valve bank. The machining precision of the hydraulic machine can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic presses, and in particular to a deviation correction system of a hydraulic press and a hydraulic press. Background Art

[0002] Hydraulic press is a device that uses the principle of hydraulic transmission to achieve mechanical energy conversion. It is widely used in industrial manufacturing, metal forming, plastic processing, construction and other fields. Due to its high efficiency and flexible operation, hydraulic press plays an increasingly important role in modern production.

[0003] However, during the operation of the hydraulic press, due to deviations in the workpiece placement position or abnormal system pressure, the movable crossbeam may be subjected to uneven force during movement, causing the movable crossbeam to swing, thereby affecting the machining accuracy of the hydraulic press. Summary of the invention

[0004] The problem solved by the invention is how to improve the machining accuracy of the hydraulic press.

[0005] In order to solve the above problems, the present invention provides a hydraulic press correction system and a hydraulic press.

[0006] In a first aspect, the present invention provides a correction system for a hydraulic press, comprising a first return cylinder, a second return cylinder, a first solenoid valve, a first control valve group, a second solenoid valve, and a second control valve group, wherein the movable end of the first return cylinder and the movable end of the second return cylinder are respectively used to be connected to a movable crossbeam of the hydraulic press, and the first return cylinder and the second return cylinder are symmetrically arranged below the movable crossbeam along a symmetric center line of the movable crossbeam, one end of the first solenoid valve is connected to an oil port of the first return cylinder, the other end of the first solenoid valve is used to be connected to a main working pump of the hydraulic press, and one end of the second solenoid valve is connected to the second The oil port of the return cylinder is connected, the other end of the second solenoid valve is used to connect to the main working pump, the first end of the first control valve group is connected to the oil port of the first return cylinder, the second end of the first control valve group is used to connect to the oil tank of the hydraulic press, the third end of the first control valve group is used to connect to the correction oil pump of the hydraulic press, the first end of the second control valve group is connected to the oil port of the second return cylinder, the second end of the second control valve group is used to connect to the oil tank, the third end of the second control valve group is used to connect to the correction oil pump, and the fourth end of the first control valve group is connected to the fourth end of the second control valve group.

[0007] Optionally, the first control valve group includes a first proportional flow valve, a first proportional servo valve and a third solenoid valve, one end of the first proportional flow valve is connected to the oil port of the first return cylinder, the other end of the first proportional flow valve is used to connect to the oil tank, the first end of the first proportional servo valve is connected to the oil port of the first return cylinder, the second end of the first proportional servo valve is used to connect to the oil tank, the third end of the first proportional servo valve is used to connect to the correction oil pump, one end of the third solenoid valve is connected to the oil port of the first return cylinder, and the other end of the third solenoid valve is connected to the fourth end of the second control valve group.

[0008] Optionally, the second control valve group includes a second proportional flow valve, a second proportional servo valve and a fourth solenoid valve, one end of the second proportional flow valve is connected to the oil port of the second return cylinder, the other end of the second proportional flow valve is used to connect to the oil tank, the first end of the second proportional servo valve is connected to the oil port of the second return cylinder, the second end of the second proportional servo valve is used to connect to the oil tank, the third end of the second proportional servo valve is used to connect to the correction oil pump, one end of the fourth solenoid valve is connected to the oil port of the second return cylinder, and the other end of the fourth solenoid valve is connected to the other end of the third solenoid valve.

[0009] Optionally, the system further includes a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is arranged at the oil port of the first return cylinder, and the second pressure sensor is arranged at the oil port of the second return cylinder.

[0010] Optionally, the system also includes a third return cylinder, a fourth return cylinder, a fifth solenoid valve, a sixth solenoid valve, a third control valve group and a fourth control valve group, one end of the fifth solenoid valve is connected to the oil port of the third return cylinder, the other end of the fifth solenoid valve is used to connect to the main working pump, one end of the sixth solenoid valve is connected to the oil port of the fourth return cylinder, the other end of the sixth solenoid valve is used to connect to the main working pump, the first end of the third control valve group is connected to the oil port of the third return cylinder, the second end of the third control valve group is used to connect to the oil tank, the third end of the third control valve group is used to connect to the correcting oil pump, the first end of the fourth control valve group is connected to the oil port of the fourth return cylinder, the second end of the fourth control valve group is used to connect to the oil tank, the third end of the fourth control valve group is used to connect to the correcting oil pump, and the fourth end of the fourth control valve group is respectively connected to the fourth ends of the first control valve group, the second control valve group and the third control valve group.

[0011] Optionally, the third control valve group includes a third proportional flow valve, a third proportional servo valve and a seventh solenoid valve, one end of the third proportional flow valve is connected to the oil port of the third return cylinder, the other end of the third proportional flow valve is used to connect to the oil tank, the first end of the third proportional servo valve is connected to the oil port of the third return cylinder, the second end of the third proportional servo valve is used to connect to the oil tank, the third end of the third proportional servo valve is used to connect to the correction oil pump, one end of the seventh solenoid valve is connected to the oil port of the third return cylinder, and the other end of the seventh solenoid valve is connected to the fourth ends of the first control valve group, the second control valve group and the fourth control valve group respectively.

[0012] Optionally, the fourth control valve group includes a fourth proportional flow valve, a fourth proportional servo valve and an eighth solenoid valve, one end of the fourth proportional flow valve is connected to the oil port of the fourth return cylinder, the other end of the fourth proportional flow valve is used to connect to the oil tank, the first end of the fourth proportional servo valve is connected to the oil port of the fourth return cylinder, the second end of the fourth proportional servo valve is used to connect to the oil tank, the third end of the fourth proportional servo valve is used to connect to the correction oil pump, one end of the eighth solenoid valve is connected to the oil port of the fourth return cylinder, and the other end of the eighth solenoid valve is respectively connected to the fourth ends of the first control valve group and the second control valve group and the other end of the seventh solenoid valve.

[0013] Optionally, the system further includes a third pressure sensor and a fourth pressure sensor, wherein the third pressure sensor is arranged at the oil port of the third return cylinder, and the fourth pressure sensor is arranged at the oil port of the fourth return cylinder.

[0014] Optionally, the system further comprises an accumulator, and the oil port of the accumulator is used to be connected to the deviation correction oil pump.

[0015] In a second aspect, the present invention provides a hydraulic press, comprising the deviation correction system of the hydraulic press as described in the first aspect.

[0016] The beneficial effects of the correction system of the hydraulic press and the hydraulic press of the present invention are as follows: the first return cylinder and the second return cylinder are connected to the main working pump by the corresponding first solenoid valve and the second solenoid valve respectively, and the first solenoid valve and the second solenoid valve respectively control the main working pump to deliver hydraulic oil to the first return cylinder and the second return cylinder, and the first solenoid valve and the second solenoid valve can be coordinated and controlled to adjust the action speed and start and stop time of the first return cylinder and the second return cylinder, thereby improving the flexibility and adaptability of the control of the return cylinder. The first return cylinder and the second return cylinder are coordinated and regulated by the first control valve group and the second control valve group, that is, the first end of the first control valve group is connected to the oil port of the first return cylinder, the second end is connected to the oil tank, and the third end is connected to the correction pump, and then the hydraulic oil in the oil tank is introduced into the return cylinder, thereby increasing the oil pressure in the return cylinder, so that the return cylinder can push and level the movable crossbeam. The second ends of the first control valve group and the second control valve group are directly connected to the oil tank respectively, and can control the first return cylinder and the second return cylinder to discharge oil and release pressure. When the movable crossbeam deflects during the descent process, it is necessary to coordinately adjust the pressure in the first return cylinder and the second return cylinder, and discharge oil and release pressure in the return cylinder at the higher end of the movable crossbeam, so that the movable crossbeam at the corresponding end falls, thereby keeping the movable crossbeam horizontal during the falling process. Through the coordination of the first solenoid valve, the second solenoid valve, the first control valve group and the second control valve group, during the operation of the hydraulic press, the position of the first return cylinder and the second return cylinder can be dynamically adjusted, so that the two return cylinders can act in coordination. When the movable crossbeam deflects, it can be quickly corrected and adjusted, so that the movable crossbeam is in a horizontal state during the movement, so that the pressure acts evenly and vertically on the workpiece, avoiding local deformation of the workpiece, and ensuring that the finished product shape is regular and tightly fitted under processes such as stamping and lamination, thereby improving the processing accuracy of the hydraulic press on the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a deviation correction system of a hydraulic press according to an embodiment of the present invention;

[0018] Figure 2 for Figure 1 Schematic diagram of the cross section of A

[0019] Figure 3 It is a schematic structural diagram of two return cylinders according to an embodiment of the present invention;

[0020] Figure 4 It is a schematic structural diagram of four return cylinders according to an embodiment of the present invention.

[0021] Description of reference numerals:

[0022] A1-first solenoid valve; A2-second solenoid valve; A3-third solenoid valve; A4-fourth solenoid valve; A5-fifth solenoid valve; A6-sixth solenoid valve; A7-seventh solenoid valve; A8-eighth solenoid valve; B1-first proportional flow valve; B2-second proportional flow valve; B3-third proportional flow valve; B4-fourth proportional flow valve; C1-first proportional servo valve; C2-second proportional servo valve; C3-third proportional servo valve; C4-fourth proportional servo valve; D1-first return cylinder; D2-second return cylinder; D3-third return cylinder; D4-fourth return cylinder; F-main working pump; G-correction oil pump; H-energy accumulator; P-oil tank; L-movable crossbeam. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0024] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0025] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to"; the term "based on" means "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0026] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0027] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0028] In the related technology, when the hydraulic press is working, the movable crossbeam may be subjected to uneven force and deflect due to factors such as imbalance in the coordination of the oil cylinder, fluctuations in the performance of the hydraulic oil, or eccentric placement of the workpiece, thereby affecting the processing accuracy of the hydraulic press. For example, when using a hydraulic press to stamp a sheet, the deflected movable crossbeam drives the upper die to press down, and the die cannot contact the workpiece smoothly at the same time. One side contacts the workpiece first, and a large pressure is concentrated instantly, causing this part of the material to begin to deform first; while the other side contacts later, the duration and degree of pressure on various parts of the workpiece vary greatly, and the thickness of the sheet finally stamped out is uneven, and wrinkles and tears may appear on the edges, seriously affecting the appearance and quality of the product.

[0029] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a hydraulic press correction system and a hydraulic press.

[0030] like Figure 1 and 2 As shown, an embodiment of the present invention provides a correction system for a hydraulic press, comprising a first return cylinder D1, a second return cylinder D2, a first solenoid valve A1, a first control valve group, a second solenoid valve A2 and a second control valve group, wherein the movable end of the first return cylinder D1 and the movable end of the second return cylinder D2 are respectively used to be connected to a movable crossbeam L of the hydraulic press, and the first return cylinder D1 and the second return cylinder D2 are symmetrically arranged below the movable crossbeam L along a symmetric center line of the movable crossbeam L, one end of the first solenoid valve A1 is connected to an oil port of the first return cylinder D1, the other end of the first solenoid valve A1 is used to be connected to a main working pump F of the hydraulic press, and the second solenoid valve A2 One end of the first control valve group is connected to the oil port of the second return cylinder D2, the other end of the second solenoid valve A2 is used to be connected to the main working pump F, the first end of the first control valve group is connected to the oil port of the first return cylinder D1, the second end of the first control valve group is used to be connected to the oil tank P of the hydraulic press, the third end of the first control valve group is used to be connected to the correcting oil pump G of the hydraulic press, the first end of the second control valve group is connected to the oil port of the second return cylinder D2, the second end of the second control valve group is used to be connected to the oil tank P, the third end of the second control valve group is used to be connected to the correcting oil pump G, and the fourth end of the first control valve group is connected to the fourth end of the second control valve group.

[0031] Specifically, Figure 3As shown, when two return cylinders are provided in the hydraulic press, the first return cylinder D1 and the second return cylinder D2 are respectively arranged at the diagonals of the movable crossbeam L, and the movable ends of the first return cylinder D1 and the second return cylinder D2 are respectively connected to the lower end of the movable crossbeam L. There are three working cylinders in the frame, and each return cylinder is provided with a displacement sensor, which is built-in or external to the hydraulic cylinder, or the displacement sensor is installed on two symmetrical corners of the movable crossbeam L, for detecting the displacement of the symmetrical angles of the movable crossbeam L. One end of the first solenoid valve A1 is connected to the oil port of the first return cylinder D1, which is the oil inlet and outlet port of the first return cylinder D1. The other end of the first solenoid valve A1 is connected to the main working pump F, and the other end of the main working pump F is connected to the oil tank P. When it is necessary to deliver hydraulic oil to the first return cylinder D1, the hydraulic oil in the oil tank P can be sucked out by the main working pump F, and after flowing through the first solenoid valve A1, it flows into the first return cylinder D1 from the oil port of the first return cylinder D1. The first solenoid valve A1 is used to control the on-off of the oil circuit between the main working pump F and the first return cylinder D1. Similarly, one end of the second solenoid valve A2 is connected to the oil port of the second return cylinder D2, and the other end of the second solenoid valve A2 is also connected to the main working pump F. When the second return cylinder D2 needs to deliver hydraulic oil, the hydraulic oil can be delivered to the second return cylinder D2 by the main working pump F. The second solenoid valve A2 is used to control the on-off of the oil circuit from the main working pump F to the second hydraulic cylinder. In order to correct the deviation of the movable crossbeam L of the hydraulic press when it deflects, a first control valve group and a second control valve group are added to the oil circuit of the first return cylinder D1 and the second return cylinder D2. The first end of the first control valve group is connected to the oil port of the first return cylinder D1, and the second end of the first control valve group is directly connected to the oil tank P of the hydraulic press. When the first return cylinder D1 needs to discharge the hydraulic oil for pressure relief, the discharged hydraulic oil can be introduced into the oil tank P through the second end of the first control valve group. The third end of the first control valve group is connected to the correction oil pump G. When the first return cylinder D1 needs to input hydraulic oil, the hydraulic oil can be delivered to it through the correction oil pump G, that is, the oil outlet of the correction oil pump G is connected to the third end of the first control valve group, and the oil inlet of the correction oil pump G is connected to the oil tank P. The fourth end of the first control valve group is connected to the fourth end of the second control valve group. When a pressure difference occurs between the hydraulic oil of the first return cylinder D1 and the second return cylinder D2, the pressure therein can be balanced through the connected ports, so that the first return cylinder D1 and the second return cylinder D2 push the movable crossbeam L in a horizontal state. Similarly, the first end of the second control valve group is connected to the oil port of the second return cylinder D2, the second end of the second control valve group is connected to the oil tank P, and the third end of the second control valve group is connected to the deviation correction oil pump G.

[0032] In this embodiment, the first return cylinder D1 and the second return cylinder D2 are connected to the main working pump F by the corresponding first solenoid valve A1 and second solenoid valve A2, respectively. The first solenoid valve A1 and the second solenoid valve A2 respectively control the main working pump F to deliver hydraulic oil to the first return cylinder D1 and the second return cylinder D2. The first solenoid valve A1 and the second solenoid valve A2 can be coordinated to adjust the action speed and start and stop time of the first return cylinder D1 and the second return cylinder D2, thereby improving the flexibility and adaptability of the control of the return cylinder. The first return cylinder D1 and the second return cylinder D2 are coordinated and regulated by the first control valve group and the second control valve group, that is, the first end of the first control valve group is connected to the oil port of the first return cylinder D1, the second end is connected to the oil tank P, and the third end is connected to the correction pump G, and then the hydraulic oil in the oil tank P is introduced into the return cylinder, the oil pressure of the return cylinder is increased, and the return cylinder can push and level the movable beam L. The second ends of the first control valve group and the second control valve group are directly connected to the oil tank P respectively, and the first return cylinder D1 and the second return cylinder D2 can be controlled to discharge oil and release pressure. When the movable crossbeam L deflects during the descent process, it is necessary to coordinately adjust the pressure in the first return cylinder D1 and the second return cylinder D2, and discharge oil and release pressure in the return cylinder at the higher end of the movable crossbeam L, so that the movable crossbeam L at the corresponding end falls, thereby keeping the movable crossbeam L horizontal during the falling process. Through the coordination of the first solenoid valve A1, the second solenoid valve A2, the first control valve group and the second control valve group, during the operation of the hydraulic press, the position of the first return cylinder D1 and the second return cylinder D2 can be dynamically adjusted, so that the two return cylinders act in coordination. When the movable crossbeam L deflects, it can be quickly corrected and adjusted, so that the movable crossbeam L is in a horizontal state during the movement, so that the pressure acts evenly and vertically on the workpiece, avoiding local deformation of the workpiece, and ensuring that the finished product shape is regular and tightly fitted under processes such as stamping and lamination, thereby improving the processing accuracy of the hydraulic press on the workpiece.

[0033] Alternatively, if Figure 1 and 2 As shown, the first control valve group includes a first proportional flow valve B1, a first proportional servo valve C1 and a third solenoid valve A3, one end of the first proportional flow valve B1 is connected to the oil port of the first return cylinder D1, the other end of the first proportional flow valve B1 is used to connect to the oil tank P, the first end of the first proportional servo valve C1 is connected to the oil port of the first return cylinder D1, the second end of the first proportional servo valve C1 is used to connect to the oil tank P, the third end of the first proportional servo valve C1 is used to connect to the correction oil pump G, one end of the third solenoid valve A3 is connected to the oil port of the first return cylinder, and the other end of the third solenoid valve A3 is connected to the fourth end of the second control valve group.

[0034] Optionally, the second control valve group includes a second proportional flow valve B2, a second proportional servo valve C2 and a fourth solenoid valve A4, one end of the second proportional flow valve B2 is connected to the oil port of the second return cylinder D2, the other end of the second proportional flow valve B2 is used to connect to the oil tank P, the first end of the second proportional servo valve C2 is connected to the oil port of the second return cylinder D2, the second end of the second proportional servo valve C2 is used to connect to the oil tank P, the third end of the second proportional servo valve C2 is used to connect to the correction oil pump G, one end of the fourth solenoid valve A4 is connected to the oil port of the second return cylinder, and the other end of the fourth solenoid valve A4 is connected to the other end of the third solenoid valve A3.

[0035] Specifically, one end of the first proportional flow valve B1 can be connected to the first return cylinder D1 as the first end of the first control valve group, and the other end of the first proportional flow valve B1 can be connected to the oil tank P as the second end of the first control valve group, that is, the first return cylinder D1 is connected to the oil tank P through the first proportional flow valve B1, so that the first return cylinder D1 is regulated by the first proportional flow valve B1. The first end of the first proportional servo valve C1 can also be connected to the first return cylinder D1 as the first end of the first control valve group, the second end of the first proportional servo valve C1 can be connected to the oil tank P as the second end of the first control valve group, and the third end of the first proportional servo valve C1 can also be connected to the correction oil pump G as the third end of the first control valve group, that is, the first return cylinder D1 is connected to the oil tank P and the correction oil pump G respectively through the first proportional servo valve C1, so that the first return cylinder D1 can be controlled by the first proportional servo valve C1 when inputting and discharging hydraulic oil, so as to realize the position closed loop of the servo valve and the displacement sensor. One end of the third solenoid valve A3 can also be connected to the first return cylinder D1 as the first end of the first control valve group, and the other end of the third solenoid valve A3 can be connected to the fourth end of the second control valve group as the fourth section of the first control valve group, that is, the first return cylinder D1 is connected to the fourth end of the second control valve group through the third solenoid valve A3, that is, the movable cross beam L connects the first return cylinder D1 and the second return cylinder D2 during the descent and lifting process of the idle stroke.

[0036] Similarly, the second return cylinder D2 is connected to the oil tank P through the second proportional flow valve B2, so that the oil discharge and pressure relief of the second return cylinder D2 are regulated by the second proportional flow valve B2. The second return cylinder D2 is connected to the oil tank P and the deviation correction oil pump G respectively through the second proportional servo valve C2, so that the second return cylinder D2 can be controlled when inputting and discharging hydraulic oil through the second proportional servo valve C2, so as to realize the position closed loop of the servo valve and the displacement sensor. The other end of the fourth solenoid valve A4 is connected to the other end of the third solenoid valve A3, so that the oil ports of the first return cylinder D1 and the second return cylinder D2 can be connected through the third solenoid valve A3 and the fourth solenoid valve A4 during the idle lowering and lifting process of the movable crossbeam L.

[0037] For example, the forging process of the hydraulic press requires the workpiece to be pressed and deformed to the required size. When the hydraulic press is working, the accurate position information of the movable crossbeam L can be obtained through the detection results of the displacement sensor. When the movable crossbeam L descends in the idle stroke and touches the workpiece or is a certain distance away from the workpiece, it is determined that the idle stroke descent is completed, and the main cylinder starts to pressurize and enters the forging stage. The movable crossbeam L descends and continues to press the workpiece downward until the workpiece is deformed to the required size. Only then does the main cylinder stop pressurizing. The workpiece is placed on the workbench. Since the position of the workpiece is not necessarily in the center of the workbench, the movable crossbeam L may deflect during the forging process. After the deflection, the entire plane of the movable crossbeam L cannot remain parallel to the plane of the workbench. This requires the return cylinder to correct the deviation and adjust the movable crossbeam L to a horizontal position to ensure the forging accuracy of the workpiece. During the idle descending stage of the movable crossbeam L, the main working cylinder is not pressurized, and the movable crossbeam L descends under the action of gravity. The return cylinder supports the movable crossbeam L and drops down. When descending, the hydraulic oil of the return cylinder is discharged back to the oil tank P. According to the descending speed of the movable crossbeam L detected by the displacement sensor, the given value of the proportional flow valve is adjusted, and then the opening degree of the proportional flow valve is adjusted, thereby adjusting the descending speed of the movable crossbeam L. The larger the opening degree of the proportional flow valve, the faster the speed; the smaller the opening degree of the proportional flow valve, the slower the speed. The corresponding operating handle can be set on the operating table. The electrical given value of the proportional flow valve changes with the swing angle of the handle, and the opening degree of the valve also changes accordingly, and then the descending speed of the movable crossbeam L also changes accordingly. After the movable crossbeam L contacts the workpiece, the main cylinder starts to pressurize forging. At this time, the proportional flow valve presets an opening given value that matches the forging speed. The pressure sensor is used to monitor the pressure of the return cylinder to assist in safety protection.

[0038] Alternatively, if Figure 1 As shown, the system further includes a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is disposed at the oil port of the first return cylinder D1 , and the second pressure sensor is disposed at the oil port of the second return cylinder D2 .

[0039] In this optional embodiment, by respectively providing a first pressure sensor and a second pressure sensor at the oil ports of the first return cylinder D1 and the second return cylinder D2, accurate pressure values ​​in the first return cylinder D1 and the second return cylinder D2 can be obtained, thereby monitoring the pressures in the first return cylinder D1 and the second return cylinder D2, thereby determining whether the pressures in the first return cylinder D1 and the second return cylinder D2 are over-pressured, for example, to perform accident analysis when an accident such as oil leakage occurs.

[0040] Alternatively, if Figure 1 and 2 As shown, the system also includes a third return cylinder D3, a fourth return cylinder D4, a fifth solenoid valve A5, a sixth solenoid valve A6, a third control valve group and a fourth control valve group, one end of the fifth solenoid valve A5 is connected to the oil port of the third return cylinder D3, the other end of the fifth solenoid valve A5 is used to connect to the main working pump F, one end of the sixth solenoid valve A6 is connected to the oil port of the fourth return cylinder D4, the other end of the sixth solenoid valve A6 is used to connect to the main working pump F, the first end of the third control valve group is connected to the third return cylinder D3, and the other end of the fifth solenoid valve A5 is used to connect to the main working pump F. The oil port of the fourth return cylinder D3 is connected, the second end of the third control valve group is used to be connected to the oil tank P, the third end of the third control valve group is used to be connected to the correcting oil pump G, the first end of the fourth control valve group is connected to the oil port of the fourth return cylinder D4, the second end of the fourth control valve group is used to be connected to the oil tank P, the third end of the fourth control valve group is used to be connected to the correcting oil pump G, and the fourth end of the fourth control valve group is respectively connected to the fourth ends of the first control valve group, the second control valve group and the third control valve group.

[0041] Optionally, the third control valve group includes a third proportional flow valve B3, a third proportional servo valve C3 and a seventh solenoid valve A7, one end of the third proportional flow valve B3 is connected to the oil port of the third return cylinder D3, the other end of the third proportional flow valve B3 is used to connect to the oil tank P, the first end of the third proportional servo valve C3 is connected to the oil port of the third return cylinder D3, the second end of the third proportional servo valve C3 is used to connect to the oil tank P, the third end of the third proportional servo valve C3 is used to connect to the correction oil pump G, one end of the seventh solenoid valve A7 is connected to the oil port of the third return cylinder, and the other end of the seventh solenoid valve A7 is respectively connected to the fourth ends of the first control valve group, the second control valve group and the fourth control valve group.

[0042] Optionally, the fourth control valve group includes a fourth proportional flow valve B4, a fourth proportional servo valve C4 and an eighth solenoid valve A8, one end of the fourth proportional flow valve B4 is connected to the oil port of the fourth return cylinder D4, the other end of the fourth proportional flow valve B4 is used to connect to the oil tank P, the first end of the fourth proportional servo valve C4 is connected to the oil port of the fourth return cylinder D4, the second end of the fourth proportional servo valve C4 is used to connect to the oil tank P, the third end of the fourth proportional servo valve C4 is used to connect to the correction oil pump G, one end of the eighth solenoid valve A8 is connected to the oil port of the fourth return cylinder, and the other end of the eighth solenoid valve A8 is respectively connected to the fourth ends of the first control valve group and the second control valve group and the other end of the seventh solenoid valve A7.

[0043] Specifically, Figure 4 As shown, when the hydraulic press is provided with four return cylinders, the first return cylinder D 1、 The second return cylinder D2, the third return cylinder D3 and the fourth return cylinder D4 are respectively arranged at the four corners of the movable beam L. The movable ends of the four return cylinders are respectively connected to the lower end of the movable beam L. There are five working cylinders in the box. The four return cylinders are provided with displacement sensors, which are built-in or external to the hydraulic cylinder, or the displacement sensors are installed on the four corners of the movable beam L, which are used to detect the displacement of the four corners of the movable beam L.

[0044] Furthermore, the main working pump F and the third return cylinder D3 are connected through the fifth solenoid valve A5, and the main working pump F and the fourth return cylinder D4 are connected through the sixth solenoid valve A6, so that the hydraulic oil of the main working pump F can enter the third return cylinder D3 and the fourth return cylinder D4 by controlling the opening and closing of the fifth solenoid valve A5 and the sixth solenoid valve A6 respectively, so that the first return cylinder D1, the second return cylinder D2, the third return cylinder D3 and the fourth return cylinder D4 can be controlled by the four solenoid valves to cooperate in pushing the movable crossbeam L, so that the movable crossbeam L can remain in a horizontal state during the lifting process. The third return cylinder D3 is connected to the oil tank P through the third proportional flow valve B3, and the fourth return cylinder D4 is connected to the oil tank P through the fourth proportional flow valve B4, and then the discharge and pressure relief of the hydraulic oil in the third return cylinder D3 and the fourth return cylinder D4 are controlled by the opening and closing of the third proportional flow valve B3 and the fourth proportional flow valve B4, so that during the lowering process of the movable crossbeam L, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 cooperate to keep the movable crossbeam L in a horizontal state during the lowering process. The first end of the third proportional servo valve C3 is connected to the oil port of the third return cylinder D3, and the third end of the third proportional servo valve C3 is connected to the correction pump G, so that the hydraulic oil in the oil tank P is introduced into the third return cylinder D3 to increase the oil pressure of the third return cylinder D3. The second end is connected to the oil tank P, and the discharged hydraulic oil is controlled to flow from the second end into the oil tank P, so as to achieve the pressure relief of the third return cylinder D3. Similarly, the first end of the fourth proportional servo valve C4 is connected to the oil port of the fourth return cylinder D4, and the second end of the fourth proportional servo valve C4 is connected to the oil tank P. When the fourth return cylinder D4 needs to be depressurized, the fourth proportional servo valve C4 can be used to control the fourth return cylinder D4 to discharge the hydraulic oil into the oil tank P. The third end of the fourth proportional servo valve C4 is connected to the deviation correction oil pump G, so that the amount of hydraulic oil entering the fourth return cylinder D4 is controlled by the fourth proportional servo valve C4. In the hydraulic press with four return cylinders, the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 are respectively closed-loop controlled with the displacement sensors of the four corresponding return cylinders, and then the piston positions in the four return cylinders are dynamically adjusted by the proportional servo valves according to the data detected by the displacement sensors, so as to achieve the purpose of leveling the movable crossbeam L. When the movable crossbeam is lowered and raised in idle travel, the first return cylinder D1, the second return cylinder D2, the third return cylinder D3 and the fourth return cylinder D4 are connected through the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8.

[0045] For example, when the movable crossbeam L stops at the highest position, the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A5 and the sixth solenoid valve A6 are closed, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are closed, the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 are opened, and the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 are closed; when the movable crossbeam L is idle and descends, the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A5 and the sixth solenoid valve A6 are closed, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are closed, the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 are opened, and the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 are closed. 5 and the sixth solenoid valve A6 continue to remain closed, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are opened to adjust the speed of the idle stroke descent, the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 continue to remain open, the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 continue to be closed; after the idle stroke descent of the movable crossbeam L ends and the master cylinder begins to be pressurized, the movable crossbeam L needs to enter the synchronous leveling and deviation correction state, the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A3 and the eighth solenoid valve A8 are opened, and the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 are closed; after the idle stroke descent of the movable crossbeam L ends and the master cylinder begins to be pressurized, the movable crossbeam L needs to enter the synchronous leveling and deviation correction state, and the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A3 and the eighth solenoid valve A8 are opened. Valve A5 and the sixth solenoid valve A6 continue to remain closed, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are opened to adjust the speed of forging descent (or make a pressure closed loop with the pressure sensor, which is related to the process requirements of the product), the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 are closed, so that the four return cylinders are controlled separately, the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 enter the working state, and make a pressure closed loop with the displacement sensors of the four corresponding return cylinders respectively. Closed-loop control is performed to achieve the purpose of leveling control of the movable crossbeam L; when the movable crossbeam L reaches the forging end point and stops, the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A5 and the sixth solenoid valve A6 continue to remain closed, the first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are closed, the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 are opened, so that the four return cylinders are connected, and the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 are controlled to be closed;When the movable crossbeam L rises, the first solenoid valve A1, the second solenoid valve A2, the fifth solenoid valve A5 and the sixth solenoid valve A6 are opened, and the hydraulic oil of the system main working pump F enters the return cylinder to lift the movable crossbeam L. The first proportional flow valve B1, the second proportional flow valve B2, the third proportional flow valve B3 and the fourth proportional flow valve B4 are closed, the third solenoid valve A3, the fourth solenoid valve A4, the seventh solenoid valve A7 and the eighth solenoid valve A8 continue to remain open, and the first proportional servo valve C1, the second proportional servo valve C2, the third proportional servo valve C3 and the fourth proportional servo valve C4 continue to remain closed; the movable crossbeam L stops after reaching the highest point and continues the next cycle action. The principle of the deviation correction of the movable crossbeam L in the forging stage is mainly to first use the proportional flow valve to roughly adjust a synchronous speed, and then supply oil through an independent deviation correction pump. The proportional servo valve finely adjusts the displacement of the four return cylinders for each return cylinder according to the position deviation to achieve the purpose of synchronous leveling and deviation correction of the movable crossbeam L. ;

[0046] Alternatively, if Figure 1 As shown, the system further includes a third pressure sensor and a fourth pressure sensor. The third pressure sensor is arranged at the oil port of the third return cylinder D3, and the fourth pressure sensor is arranged at the oil port of the fourth return cylinder D4.

[0047] In this optional embodiment, by respectively providing a third pressure sensor and a fourth pressure sensor at the oil ports of the third return cylinder D3 and the fourth return cylinder D4, accurate pressure values ​​in the third return cylinder D3 and the fourth return cylinder D4 can be obtained, thereby monitoring the pressures in the third return cylinder D3 and the fourth return cylinder D4, thereby determining whether the pressures in the third return cylinder D3 and the fourth return cylinder D4 are over-pressured, and when an accident such as oil leakage occurs in the hydraulic press of the four return cylinders, the pressure value can be used for accident analysis.

[0048] Alternatively, if Figure 1 As shown, the system further includes an accumulator H, and the oil port of the accumulator H is used to be connected to the deviation correction oil pump G.

[0049] In this optional embodiment, when the correction oil pump G is underpowered or works intermittently, the stored hydraulic oil is released through the accumulator H to continue to supply hydraulic oil to the return cylinder, so that the movable crossbeam L continues to maintain a horizontal state.

[0050] A hydraulic press provided by an embodiment of the present invention includes the deviation correction system of the hydraulic press as described above.

[0051] The beneficial effects of the hydraulic press of this embodiment relative to the prior art are the same as those of the deviation correction system of the hydraulic press described above, and will not be described in detail here.

[0052] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A hydraulic press correction system, characterized in that: The invention comprises a first return cylinder, a second return cylinder, a first solenoid valve, a first control valve group, a second solenoid valve and a second control valve group, wherein the movable end of the first return cylinder and the movable end of the second return cylinder are respectively used to be connected to the movable crossbeam of the hydraulic press, and the first return cylinder and the second return cylinder are symmetrically arranged below the movable crossbeam along the symmetry center line of the movable crossbeam, one end of the first solenoid valve is connected to the oil port of the first return cylinder, and the other end of the first solenoid valve is used to be connected to the main working pump of the hydraulic press, one end of the second solenoid valve is connected to the oil port of the second return cylinder, and the The other end of the second solenoid valve is used to connect to the main working pump, the first end of the first control valve group is connected to the oil port of the first return cylinder, the second end of the first control valve group is used to connect to the oil tank of the hydraulic press, the third end of the first control valve group is used to connect to the correction oil pump of the hydraulic press, the first end of the second control valve group is connected to the oil port of the second return cylinder, the second end of the second control valve group is used to connect to the oil tank, the third end of the second control valve group is used to connect to the correction oil pump, and the fourth end of the first control valve group is connected to the fourth end of the second control valve group.

2. The hydraulic press correction system according to claim 1, characterized in that: The first control valve group includes a first proportional flow valve, a first proportional servo valve and a third solenoid valve, one end of the first proportional flow valve is connected to the oil port of the first return cylinder, the other end of the first proportional flow valve is used to connect to the oil tank, the first end of the first proportional servo valve is connected to the oil port of the first return cylinder, the second end of the first proportional servo valve is used to connect to the oil tank, the third end of the first proportional servo valve is used to connect to the correction oil pump, one end of the third solenoid valve is connected to the oil port of the first return cylinder, and the other end of the third solenoid valve is connected to the fourth end of the second control valve group.

3. The hydraulic press correction system according to claim 2, characterized in that: The second control valve group includes a second proportional flow valve, a second proportional servo valve and a fourth solenoid valve, one end of the second proportional flow valve is connected to the oil port of the second return cylinder, the other end of the second proportional flow valve is used to be connected to the oil tank, the first end of the second proportional servo valve is connected to the oil port of the second return cylinder, the second end of the second proportional servo valve is used to be connected to the oil tank, the third end of the second proportional servo valve is used to be connected to the correction oil pump, one end of the fourth solenoid valve is connected to the oil port of the second return cylinder, and the other end of the fourth solenoid valve is connected to the other end of the third solenoid valve.

4. The hydraulic press correction system according to claim 1, characterized in that: It also includes a first pressure sensor and a second pressure sensor, wherein the first pressure sensor is arranged at the oil port of the first return cylinder, and the second pressure sensor is arranged at the oil port of the second return cylinder.

5. The hydraulic press correction system according to claim 1, characterized in that: It also includes a third return cylinder, a fourth return cylinder, a fifth solenoid valve, a sixth solenoid valve, a third control valve group and a fourth control valve group, one end of the fifth solenoid valve is connected to the oil port of the third return cylinder, the other end of the fifth solenoid valve is used to connect to the main working pump, one end of the sixth solenoid valve is connected to the oil port of the fourth return cylinder, the other end of the sixth solenoid valve is used to connect to the main working pump, the first end of the third control valve group is connected to the oil port of the third return cylinder, the second end of the third control valve group is used to connect to the oil tank, the third end of the third control valve group is used to connect to the correcting oil pump, the first end of the fourth control valve group is connected to the oil port of the fourth return cylinder, the second end of the fourth control valve group is used to connect to the oil tank, the third end of the fourth control valve group is used to connect to the correcting oil pump, and the fourth end of the fourth control valve group is connected to the fourth ends of the first control valve group, the second control valve group and the third control valve group respectively.

6. The hydraulic press correction system according to claim 5, characterized in that: The third control valve group includes a third proportional flow valve, a third proportional servo valve and a seventh solenoid valve, one end of the third proportional flow valve is connected to the oil port of the third return cylinder, the other end of the third proportional flow valve is used to connect to the oil tank, the first end of the third proportional servo valve is connected to the oil port of the third return cylinder, the second end of the third proportional servo valve is used to connect to the oil tank, the third end of the third proportional servo valve is used to connect to the correction oil pump, one end of the seventh solenoid valve is connected to the oil port of the third return cylinder, and the other end of the seventh solenoid valve is connected to the fourth ends of the first control valve group, the second control valve group and the fourth control valve group respectively.

7. The hydraulic press correction system according to claim 6, characterized in that: The fourth control valve group includes a fourth proportional flow valve, a fourth proportional servo valve and an eighth solenoid valve, one end of the fourth proportional flow valve is connected to the oil port of the fourth return cylinder, the other end of the fourth proportional flow valve is used to connect to the oil tank, the first end of the fourth proportional servo valve is connected to the oil port of the fourth return cylinder, the second end of the fourth proportional servo valve is used to connect to the oil tank, the third end of the fourth proportional servo valve is used to connect to the correction oil pump, one end of the eighth solenoid valve is connected to the oil port of the fourth return cylinder, and the other end of the eighth solenoid valve is respectively connected to the fourth ends of the first control valve group and the second control valve group and the other end of the seventh solenoid valve.

8. The hydraulic press correction system according to claim 5, characterized in that: It also includes a third pressure sensor and a fourth pressure sensor. The third pressure sensor is arranged at the oil port of the third return cylinder, and the fourth pressure sensor is arranged at the oil port of the fourth return cylinder.

9. The hydraulic press correction system according to claim 1, characterized in that: It also includes an accumulator, and the oil port of the accumulator is used to be connected to the deviation-correcting oil pump.

10. A hydraulic press, characterized in that: A deviation correction system for a hydraulic press comprising the steps of:

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