Hydraulic protection system of press machine and press machine

Abstract

The invention provides a hydraulic protection system of a press machine and the press machine, and relates to the technical field of press machine equipment.The hydraulic protection system of the press machine comprises a hydraulic station, a plurality of oil inlet pipes, a plurality of oil return pipes, a plurality of hydraulic protection oil cylinders, a plurality of pressure detection structures and a plurality of unloading valve banks.The hydraulic station is provided with an oil outlet and an oil return opening; the two ends of each oil inlet pipe are communicated with the oil outlet and the corresponding hydraulic protection oil cylinder respectively, the overload protection valve comprises a working oil cavity and a first oil return cavity, and the first oil return cavity is communicated with the oil return opening through an oil return pipe; the pressure detection structures are electrically connected with the electromagnetic valves, and the multiple electromagnetic valves are used for being opened at the same time according to at least one overload signal; the electromagnetic valve comprises an electromagnetic valve pressure oil cavity and a second oil return cavity, the electromagnetic valve pressure oil cavity is communicated with the working oil cavity, and the second oil return cavity is communicated with the oil return opening through an oil return pipe. When a single hydraulic protection oil cylinder is overloaded, all the hydraulic protection oil cylinders can be unloaded, so that the safe work of the press is ensured.

Description

Technical Field

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

[0002] The press is a general purpose press with mechanical transmission. It has the characteristics of wide application and high production efficiency. The press can be widely used in cutting, punching, blanking, bending, riveting and forming processes.

[0003] At present, the press commonly used in automobile cover stamping lines is usually a closed four-point press. In other words, the overload protection system of the press mainly includes a hydraulic oil tank, four hydraulic protection cylinders and a gas-liquid overload protection valve. The four hydraulic protection cylinders can cooperate with the press slider to perform stamping operations on the automobile cover on the mold. The four pressure points (hydraulic protection cylinders) of this type of press share an overload protection valve (that is, the working oil chambers of the four pressure points are interconnected and connected to the hydraulic oil tank through the high-pressure oil circuit through the gas-liquid overload protection valve). When the total tonnage of the four pressure points exceeds the set value, the gas-liquid overload protection valve will perform the unloading action.

[0004] However, in the actual operation of the press, due to eccentric loading or other unexpected situations, a certain pressure point may be overloaded alone while the overall load does not reach the overload tonnage. In this case, the above-mentioned gas-liquid overload protection valve will not operate. As the pressure of the overloaded pressure point gradually increases, it is easy to cause damage to the transmission mechanism, mold, etc. of the press, thereby greatly reducing the service life of the press. Summary of the invention

[0005] The problem solved by the invention is how to avoid overloading of a single hydraulic protection oil cylinder in a press without generating a unloading action and causing losses to the transmission mechanism and the mold of the press.

[0006] In order to solve the above problems, the present invention provides a hydraulic protection system for a press and a press.

[0007] In a first aspect, the present invention provides a hydraulic protection system for a press machine, comprising a hydraulic station, a plurality of oil inlet pipes, a plurality of oil return pipes, a plurality of hydraulic protection cylinders, a plurality of pressure detection structures and a plurality of unloading valve groups, wherein the hydraulic station has an oil outlet and an oil return port, and the two ends of each of the oil inlet pipes are respectively connected to the oil outlet and the corresponding hydraulic protection cylinder, the unloading valve group comprises an overload protection valve and a solenoid valve, the overload protection valve comprises a working oil chamber and a first oil return chamber, the working oil chamber is connected to the corresponding hydraulic protection cylinder, and the first oil return chamber is connected to the oil return port through the corresponding oil return pipe;

[0008] The pressure detection structure is used to detect the overload signal of the corresponding hydraulic protection cylinder. The pressure detection structure is electrically connected to the solenoid valve. The multiple solenoid valves are used to open simultaneously according to at least one overload signal; the solenoid valve includes a solenoid valve pressure oil chamber and a second oil return chamber. The solenoid valve pressure oil chamber is connected to the working oil chamber, and the second oil return chamber is connected to the oil return port through the oil return pipe.

[0009] Optionally, the overload protection valve comprises a main valve structure, the main valve structure comprises a main valve body, a main valve core, a main valve spring and a first screw plug, a first installation cavity is provided inside the main valve body, and the main valve core is arranged in the first installation cavity; a second installation cavity is provided inside the main valve core, a part of the main valve spring is arranged in the second installation cavity, and another part of the main valve spring is in the first installation cavity;

[0010] The working oil chamber and the first oil return chamber are provided inside the main valve body; the first screw plug is arranged in the main valve core, and the first screw plug has a main valve damping hole, and one end of the main valve damping hole is connected to the working oil chamber.

[0011] Optionally, the overload protection valve further comprises a pilot valve structure, the pilot valve structure comprises a pilot valve body, a pilot valve core and a pilot spring, a third installation cavity is provided inside the pilot valve body, the pilot valve core and the pilot spring are arranged in the third installation cavity of the pilot valve body, and the pilot spring is sleeved on the pilot valve core;

[0012] The pilot valve body has a pilot pressure oil chamber and a pilot oil unloading chamber. The other end of the main valve damping hole is connected to the pilot oil unloading chamber via the pilot pressure oil chamber and the third installation chamber in sequence. The pilot oil unloading chamber is connected to the first oil return chamber.

[0013] Optionally, when the solenoid valve is opened,

[0014] The second oil return chamber of the solenoid valve is connected to the oil return pipe through the first oil return chamber; or, a connecting flow channel is provided on the main valve body, and the second oil return chamber of the solenoid valve is connected to the oil return pipe through the connecting flow channel.

[0015] Optionally, when the pressure difference at both ends of the main valve damping hole increases, the main valve spring pushes the main valve core to move in the first installation cavity, and the working oil cavity is connected to the first oil return cavity;

[0016] The main valve body is provided with an oil discharge port, one end of which is connected to the first oil return chamber, and the other end of which is connected to the oil return port through the oil return pipe.

[0017] Optionally, the hydraulic protection system of the press machine further includes a plurality of one-way valves, each of the one-way valves being arranged on each of the corresponding oil inlet pipes, and the one-way valves being used to limit the hydraulic oil of the hydraulic protection cylinder from flowing in the reverse direction toward the oil outlet.

[0018] Optionally, the pressure detection structure includes a plurality of pressure detection devices, and the plurality of pressure detection devices are arranged at intervals on the oil inlet pipe, and the plurality of pressure detection devices are configured to have overload pressure values ​​of different levels.

[0019] Optionally, the hydraulic protection system of the press further includes a plurality of pressure gauges, each of which is connected to the corresponding hydraulic protection cylinder and is used to display the pressure value of the corresponding hydraulic protection cylinder.

[0020] Optionally, the hydraulic protection system of the press also includes a control device, and each of the pressure detection structures is respectively arranged at a position of the corresponding oil inlet pipe close to the hydraulic protection cylinder. The multiple pressure detection structures are respectively electrically connected to the control device, and the control device is electrically connected to the multiple solenoid valves, for controlling the multiple solenoid valves to open simultaneously according to at least one overload signal.

[0021] In a second aspect, the present invention provides a press machine, comprising the hydraulic protection system for the press machine as described above.

[0022] The hydraulic protection system of the press and the press of the present invention have the following beneficial effects:

[0023] The hydraulic protection system of the press may include multiple hydraulic protection cylinders. The oil outlets of the hydraulic station are connected to the corresponding hydraulic protection cylinders through multiple oil inlet pipes, so that the hydraulic station can transport the hydraulic oil to the hydraulic protection cylinders through the oil outlets via the oil inlet pipes to provide hydraulic power for the operation of the hydraulic protection cylinders.

[0024] A pressure detection structure and a unloading valve group can be configured for each hydraulic protection cylinder. When at least one pressure detection structure detects an overload signal in the corresponding hydraulic protection cylinder, the overload protection valve in the unloading valve group corresponding to the hydraulic protection cylinder with the overload signal is actively opened under the action of the hydraulic oil pressure in the hydraulic protection cylinder, so that the hydraulic oil in the hydraulic protection cylinder with the overload signal is unloaded to the hydraulic oil tank of the hydraulic station through the working oil chamber, the first return oil chamber, the return oil pipe, and the return oil port of the load protection valve in sequence, so as to realize the active unloading operation of the hydraulic protection cylinder with the overload signal.

[0025] At the same time, the pressure detection structure also sends the overload signal to the pressure detection structures corresponding to other hydraulic protection cylinders. Regardless of whether the pressure of the unloading valve groups corresponding to other hydraulic protection cylinders reaches the unloading pressure, the solenoid valves of all unloading valve groups will be opened simultaneously according to the overload signal of the pressure detection structure to actively unload. Since the solenoid valve pressure oil chamber and the second return oil chamber of the solenoid valve are respectively connected to the working oil chamber and the first return oil chamber of the corresponding overload protection valve, the hydraulic oil in each hydraulic protection cylinder is unloaded to the hydraulic oil tank of the hydraulic station through the working oil chamber of the load protection valve, the solenoid valve pressure oil chamber and the second return oil chamber of the solenoid valve, the return oil pipe, and the return oil port in turn, so as to realize the unloading operation of all hydraulic protection cylinders of the press, and effectively avoid the related technology that a single hydraulic protection cylinder (pressure point) of the press is overloaded alone and the overall overload tonnage is not reached, resulting in damage to the transmission mechanism and mold of the entire press, thereby ensuring the safety of the press and correspondingly extending the service life of the press. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a partial principle structure diagram of the overload protection system of the press in the related technology.

[0027] Figure 2 It is a principle structure diagram of the hydraulic protection system of the press in the embodiment of the present invention.

[0028] Figure 3 It is a partial principle structure diagram of the hydraulic protection system of the press in the embodiment of the present invention.

[0029] Figure 4 It is a principle structure diagram of the unloading valve group in an embodiment of the present invention.

[0030] Figure 5 This is one of the principle structural diagrams of the flow path of the hydraulic oil when the solenoid valve is opened in an embodiment of the present invention.

[0031] Figure 6 This is the second principle structural diagram of the flow path of the hydraulic oil when the solenoid valve is opened in an embodiment of the present invention.

[0032] Figure 7 This is a principle structural diagram of a hydraulic protection system in an embodiment of the present invention when the system pressure is normal.

[0033] Figure 8 This is a structural diagram of the unloading principle when the pressure at a certain pressure point reaches a set overload pressure in an embodiment of the present invention.

[0034] Fig. 9 This is a structural diagram of the unloading principle when the solenoid valve is opened in an embodiment of the present invention.

[0035] Fig.10 This is a structural diagram of the unloading principle when the main valve structure is opened in an embodiment of the present invention.

[0036] Fig.11 Schematic diagram of the structure of a press in an embodiment of the present invention.

[0037] Description of reference numerals:

[0038] 1'-Hydraulic oil tank; 2'-Protective oil cylinder; 3'-Gas-liquid overload protection valve; 4'-High-pressure oil circuit;

[0039] 1-Hydraulic station; 2-Hydraulic protection cylinder; 3-Unloading valve group; 31-Overload protection valve; 311-Main valve structure; 3111-Main valve body; 3112-Main valve core; 3113-Main valve spring; 3114-First screw plug; 3115-Working oil chamber; 3116-First return oil chamber; 3117-Main valve damping hole; 3118-Unloading port; 3119-Connecting flow channel; 312-Pilot valve structure; 3121-Pilot valve body; 3122-Pilot valve core; 3123-Pilot spring; 3124-First Second screw plug; 3125-third installation chamber; 3126-pilot pressure oil chamber; 3127-pilot oil unloading chamber; 3128-adjusting bolt; 32-solenoid valve; 321-solenoid valve pressure oil chamber; 322-second oil return chamber; 4-oil inlet pipe; 5-oil return pipe; 6-pressure detection structure; 61-pressure detection device; 7-check valve; 8-pressure gauge; 100-hydraulic protection system; 200-upper beam; 300-slider; 400-column; 500-workbench; 600-base; 700-transmission mechanism. DETAILED DESCRIPTION

[0040] 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.

[0041] 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.

[0042] 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".

[0043] The press is a general purpose press with mechanical transmission. It has the characteristics of wide application and high production efficiency. The press can be widely used in cutting, punching, blanking, bending, riveting and forming processes.

[0044] At present, the press commonly used in automobile panel stamping lines is usually a closed four-point press. In other words, combined with Figure 1 As shown, the overload protection system of the press mainly includes a hydraulic oil tank 1', four oil cylinders 2', a high-pressure oil circuit 4' and a gas-liquid overload protection valve 3'. The four hydraulic protection cylinders 2' can cooperate with the slider of the press to perform stamping operations on the automobile cover on the mold. The four pressure points (hydraulic protection cylinders 2') of this type of press share an overload protection valve (that is, the working oil chambers of the four pressure points are interconnected and connected to the hydraulic oil tank 1' through the high-pressure oil circuit 4' and the gas-liquid overload protection valve 3'). When the total tonnage of the four pressure points exceeds the set value, the gas-liquid overload protection valve 3' will perform the unloading action.

[0045] However, in the actual operation of the press, due to eccentric loading or other unexpected situations, a certain pressure point may be overloaded alone while the overall load does not reach the overload tonnage. In this case, the above-mentioned gas-liquid overload protection valve 3' will not operate. As the pressure of the overloaded pressure point gradually increases, it is easy to cause damage to the transmission mechanism, mold, etc. of the press, thereby greatly reducing the service life of the press.

[0046] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a hydraulic protection system for a press and a press.

[0047] like Figure 2 and Figure 3As shown, a hydraulic protection system for a press provided by an embodiment of the present invention comprises a hydraulic station 1, a plurality of oil inlet pipes 4, a plurality of oil return pipes 5, a plurality of hydraulic protection cylinders 2, a plurality of pressure detection structures 6 and a plurality of unloading valve groups 3, wherein the hydraulic station 1 has an oil outlet and an oil return port, and the two ends of each of the oil inlet pipes 4 are respectively connected to the oil outlet and the corresponding hydraulic protection cylinder 2, the unloading valve group 3 comprises an overload protection valve 31 and a solenoid valve 32, the overload protection valve 31 comprises a working oil chamber 3115 and a first oil return chamber 3116, the working oil chamber 3115 is connected to the corresponding hydraulic protection cylinder 2, and the first oil return chamber 3116 is connected to the oil return port through the corresponding oil return pipe 5;

[0048] The pressure detection structure 6 is used to detect the overload signal of the corresponding hydraulic protection cylinder 2. The pressure detection structure 6 is electrically connected to the solenoid valve 32. Multiple solenoid valves 32 are used to open simultaneously according to at least one overload signal; the solenoid valve 32 includes a solenoid valve pressure oil chamber 321 and a second return oil chamber 322. The solenoid valve pressure oil chamber 321 is connected to the working oil chamber 3115, and the second return oil chamber 322 is connected to the return oil port through the return oil pipe 5.

[0049] Specifically, the hydraulic station 1 includes at least an oil pump and a hydraulic oil tank. The input end of the oil pump is connected to the hydraulic oil tank, and the output end of the oil pump has the oil outlet, which is connected to the hydraulic protection cylinder 2 via the oil inlet pipe 4; the first oil return chamber 3116 of the overload protection valve 31 and the second oil return chamber 322 of the solenoid valve 32 can be respectively connected to one end of the return oil pipe 5, the hydraulic oil tank has the oil return port, and the other end of the return oil pipe 5 is connected to the oil return port.

[0050] In this embodiment, the press may include multiple hydraulic protection cylinders 2, and the oil outlets of the hydraulic station 1 are respectively connected to the corresponding hydraulic protection cylinders 2 through multiple oil inlet pipes 4, so that the hydraulic station 1 can transport the hydraulic oil through the oil inlet pipe 4 to the hydraulic protection cylinder 2 through the oil outlet, so as to provide hydraulic power for the operation of the hydraulic protection cylinder 2.

[0051] A pressure detection structure 6 and a unloading valve group 3 can be configured for each hydraulic protection cylinder 2. When at least one pressure detection structure 6 detects an overload signal in the corresponding hydraulic protection cylinder 2, the overload protection valve 31 in the unloading valve group 3 corresponding to the hydraulic protection cylinder 2 with the overload signal is actively opened under the action of the hydraulic oil pressure in the hydraulic protection cylinder 2, so that the hydraulic oil in the hydraulic protection cylinder 2 with the overload signal is unloaded to the hydraulic oil tank of the hydraulic station 1 through the working oil chamber 3115, the first return oil chamber 3116, the return oil pipe 5, and the return oil port of the load protection valve 31 in sequence, so as to realize the active unloading operation of the hydraulic protection cylinder 2 with the overload signal.

[0052] At the same time, the pressure detection structure 6 also sends the overload signal to the pressure detection structure 6 corresponding to other hydraulic protection cylinders 2. Regardless of whether the pressure of the unloading valve group 3 corresponding to other hydraulic protection cylinders 2 reaches the unloading pressure, the solenoid valves 32 of all the unloading valve groups 3 will be opened at the same time according to the overload signal of the pressure detection structure 6 to actively unload. Since the solenoid valve pressure oil chamber 321 and the second oil return chamber 322 of the solenoid valve 32 are respectively connected to the corresponding working oil chamber 3115 and the first oil return chamber 3116 of the overload protection valve 31, each hydraulic protection cylinder The hydraulic oil in 2 is unloaded to the hydraulic oil tank of the hydraulic station 1 through the working oil chamber 3115 of the load protection valve 31, the solenoid valve pressure oil chamber 321 and the second return oil chamber 322 of the solenoid valve 32, the return oil pipe 5, and the return oil port in turn, so as to realize the unloading operation of all the hydraulic protection cylinders 2 of the press, and effectively avoid the damage to the transmission mechanism and mold of the entire press caused by the overload of a single hydraulic protection cylinder 2 (pressure point) of the press in the related technology without reaching the overload tonnage as a whole, thereby ensuring the safe operation of the press and correspondingly extending the service life of the press.

[0053] Optionally, combined Figure 4 As shown, the overload protection valve 31 includes a main valve structure 311, and the main valve structure 311 includes a main valve body 3111, a main valve core 3112, a main valve spring 3113 and a first screw plug 3114. A first installation cavity is provided inside the main valve body 3111, and the main valve core 3112 is arranged in the first installation cavity; a second installation cavity is provided inside the main valve core 3112, and a part of the main valve spring 3113 is arranged in the second installation cavity, and another part of the main valve spring 3113 is in the first installation cavity;

[0054] The working oil chamber 3115 and the first oil return chamber 3116 are provided inside the main valve body 3111; the first screw plug 3114 is arranged in the main valve core 3112, and the first screw plug 3114 has a main valve damping hole 3117, and one end of the main valve damping hole 3117 is connected to the working oil chamber 3115.

[0055] Specifically, the main valve core 3112 can be connected to the main valve body 3111 in the following manner, for example, a first installation cavity can be provided inside the main valve body 3111, and the main valve core 3112 is provided in the first installation cavity of the main valve body 3111. The size of the main valve core 3112 along its own axial direction is smaller than the size of the first installation cavity, thereby providing a movable space for the main valve core 3112 to move in the first installation cavity to open the main valve structure 311.

[0056] The main valve spring 3113 can be connected to the main valve core 3112 in the following manner. For example, a second installation cavity can be set inside the main valve core 3112, and most of the structure of the main valve spring 3113 is in the second installation cavity of the main valve core 3112, and a small part of the structure of the main valve spring 3113 is in the first installation cavity; wherein the axis of the main valve spring 3113 can coincide with the axis of the main valve core 3112. wherein one end of the main valve spring 3113 can be fixedly connected to one end of the inner wall of the main valve core 3112, and the other end of the main valve spring 3113 can be connected to the inner wall of the second installation cavity.

[0057] The main valve body 3111 is provided with a first oil return chamber 3116 on the outer side of the main valve core 3112 . A working oil chamber 3115 may be provided at a position of the main valve body 3111 close to the hydraulic protection cylinder 2 . The working oil chamber 3115 may be connected to the working chamber of the hydraulic protection cylinder 2 .

[0058] A first installation groove can be opened at the position of the main valve core 3112 facing the working oil chamber 3115, and the first screw plug 3114 is installed in the first installation groove. The first screw plug 3114 has a main valve blocking hole. One end of the main valve damping hole 3117 can be connected to the working oil chamber 3115, and the other end can be connected to the solenoid valve pressure oil chamber 321 through the second installation chamber of the main valve core 3112.

[0059] In this optional embodiment, since one end of the main valve damping hole 3117 is connected to the working oil chamber 3115, one end of the main valve damping hole 3117 can be connected to the working oil chamber 3115, and the other end can be connected to the solenoid valve pressure oil chamber 321. Therefore, when the solenoid valve 32 is opened, the hydraulic oil in the working chamber of the hydraulic protection cylinder 2 flows back to the hydraulic station 1 through the working oil chamber 3115, the main valve damping hole 3117, the solenoid valve pressure oil chamber 321, the second return oil chamber 322, the first return oil chamber 3116 and the return oil pipe 5 in sequence, thereby not only realizing the unloading action Moreover, as the pressure in the working oil chamber 3115 of the main valve body 3111 decreases, the pressure difference at both ends of the main valve damping hole 3117 increases, so that the pressure of the hydraulic oil in the pressure oil chamber 321 of the solenoid valve is greater than the force of the main valve spring 3113, so that the main valve core 3112 is driven by the main valve spring 3113 to move in the first installation chamber of the main valve body 3111 to open the main valve structure 311, which helps the hydraulic oil in the working oil chamber 3115 of the main valve body 3111 to be unloaded to the hydraulic station 1 as soon as possible, thereby correspondingly improving the unloading effect of the hydraulic oil.

[0060] Optionally, combined Figure 4As shown, the overload protection valve 31 further includes a pilot valve structure 312, the pilot valve structure 312 includes a pilot valve body 3121, a pilot valve core 3122 and a pilot spring 3123, a third installation cavity 3125 is provided inside the pilot valve body 3121, the pilot valve core 3122 and the pilot spring 3123 are arranged in the third installation cavity 3125 of the pilot valve body 3121, and the pilot spring 3123 is sleeved on the pilot valve core 3122;

[0061] The pilot valve body 3121 has a pilot pressure oil chamber 3126 and a pilot oil unloading chamber 3127. The other end of the main valve damping hole 3117 is connected to the pilot oil unloading chamber 3127 via the pilot pressure oil chamber 3126 and the third installation chamber 3125 in sequence. The pilot oil unloading chamber 3127 is connected to the first return oil chamber 3116.

[0062] Specifically, the pilot valve body 3121 can be connected to the main valve body 3111 to realize the assembly of the pilot valve structure 312 and the main valve structure 311; the pilot valve core 3122 can be connected to the pilot valve body 3121 in the following manner, for example, a third installation cavity 3125 can be provided inside the pilot valve body 3121, and the pilot valve core 3122 and the pilot spring 3123 are provided in the third installation cavity 3125 of the pilot valve body 3121. The size of the pilot valve core 3122 along its own axial direction is smaller than the size of the third installation cavity 3125, thereby providing a movable space for the pilot valve core 3122 to move in the third installation cavity 3125 to open the pilot valve structure 312.

[0063] The pilot spring 3123 may be connected to the pilot valve core 3122 in the following manner: the pilot spring 3123 is sleeved on the pilot valve core 3122 ; wherein the axis of the pilot spring 3123 may coincide with the axis of the pilot valve core 3122 .

[0064] The pilot valve structure 312 also includes a second screw plug 3124 and an adjusting bolt 3128. Since the pilot valve body 3121 needs to be processed to open a third installation cavity 3125, processing holes are respectively opened at the two opposite ends of the pilot valve body 3121 corresponding to the third installation cavity 3125, and the second screw plug 3124 can be installed at one of the processing holes. The adjusting bolt 3128 can be installed at another processing hole of the pilot valve body 3121 by threading, and the bottom end of the adjusting bolt 3128 can be connected to the pilot valve core 3122. The adjusting bolt 3128 can be rotated to adjust the pressure of the pilot spring 3123 sleeved on the pilot valve core 3122, thereby adjusting the overload pressure of the pilot valve structure 312.

[0065] A pilot pressure oil chamber 3126 is opened at a position in the pilot valve body 3121 corresponding to the second installation chamber in the main valve structure 311, and the main valve damping hole 3117 is connected to the pilot pressure oil chamber 3126 through the second installation chamber; a pilot oil unloading chamber 3127 is set between the third installation chamber 3125 of the pilot valve body 3121 and the first oil return chamber 3116 of the main valve body 3111. In other words, the third installation chamber 3125 in the pilot valve body 3121 is connected to the first oil return chamber 3116 of the main valve body 3111 through the pilot oil unloading chamber 3127.

[0066] In this optional embodiment, since the other end of the main valve damping hole 3117 is connected to the pilot oil unloading chamber 3127 via the pilot pressure oil chamber 3126 and the third installation chamber 3125 in sequence, and the pilot oil unloading chamber 3127 is connected to the first return oil chamber 3116, when the hydraulic protection cylinder 2 just starts to generate an overload signal, the hydraulic oil in the hydraulic protection cylinder 2 can be connected to the first return oil chamber 3116 in the main valve body 3111 from the main valve damping hole 3117 of the main valve structure 311 via the second installation chamber, the pilot pressure oil chamber 3126 of the pilot valve structure 312, the third installation chamber 3125, and the pilot oil unloading chamber 3127 in sequence. Since the first return oil chamber 3116 is connected to the hydraulic station 1 via the return oil pipe 5, the hydraulic oil in the first return oil chamber 3116 flows back to the hydraulic station 1 via the return oil pipe 5, thereby realizing the unloading action.

[0067] Optionally, combined Figure 5 and Figure 6 As shown, the main valve structure 311 has two different structures. When the solenoid valve 32 is opened,

[0068] One is that the second oil return chamber 322 of the solenoid valve 32 is connected to the oil return pipe 5 through the first oil return chamber 3116; or, the other is that a connecting channel 3119 is provided on the main valve body 3111, and the second oil return chamber 322 of the solenoid valve 32 is connected to the oil return pipe 5 through the connecting channel 3119.

[0069] Specifically, when the solenoid valve 32 is opened, the hydraulic oil can be unloaded to the hydraulic station 1 through the solenoid valve 32 by selecting one of the following two paths, for example, combining Figure 5As shown, the main valve damping hole 3117 is connected to the oil return pipe 5 through the second installation cavity, the pilot pressure oil cavity 3126, the solenoid valve pressure oil cavity 321 of the solenoid valve 32, the second oil return cavity 322, and the first oil return cavity 3116 of the main valve structure 311 in sequence; so that when the solenoid valve is opened, the hydraulic oil of the hydraulic protection cylinder 2 can flow through the main valve damping hole 3117, through the second installation cavity, and to the pilot pressure oil cavity 3126 in sequence. At this time, the hydraulic oil is split, and most of the hydraulic oil flows through the solenoid valve pressure oil cavity 321 and the second oil return cavity 322 of the solenoid valve 32 to the first oil return cavity 3116 of the main valve structure 311, and another part of the hydraulic oil flows through the third installation cavity 3125 of the pilot valve body 3121 and the pilot oil unloading cavity 3127 to the first oil return cavity 3116. Finally, the hydraulic oil in the first oil return cavity 3116 is unloaded through the oil return pipe 5 to the hydraulic oil tank of the hydraulic station 1.

[0070] Or, combined Figure 6 As shown, a connecting flow channel 3119 for connecting the second oil return chamber 322 and the oil return pipe 5 is provided on the main valve body 3111; the main valve damping hole 3117 is connected to the oil return pipe 5 via the second installation chamber, the pilot pressure oil chamber 3126, the solenoid valve pressure oil chamber 321 of the solenoid valve 32, the second oil return chamber 322, and the connecting flow channel 3119 in sequence. In other words, the connecting flow channel 3119 is different from the oil unloading port of the first oil return chamber 3116, so that the connecting flow channel 3119 and the first oil return chamber 3116 can be connected to the oil return port of the hydraulic station through different oil return pipes.

[0071] Among them, the hydraulic oil of the hydraulic protection cylinder 2 can flow through the main valve damping hole 3117 and the second installation cavity in turn to the pilot pressure oil cavity 3126 for diversion. Most of the hydraulic oil is unloaded to the hydraulic oil tank of the hydraulic station 1 through the solenoid valve pressure oil cavity 321, the second return oil cavity 322, the connecting flow channel 3119, and a return oil pipe 5 of the solenoid valve 32. Another part of the hydraulic oil is unloaded to the hydraulic oil tank of the hydraulic station 1 through the third installation cavity 3125 of the pilot valve body 3121, the pilot oil unloading cavity 3127, the first return oil cavity 3116, and another return oil pipe 5. In short, the hydraulic oil of the above two different flow paths is unloaded from different oil unloading ports, which is equivalent to increasing the unloading flow channel of the hydraulic oil, so as to improve the unloading speed and effect of the hydraulic protection cylinder, and effectively avoid the expansion of faults caused by overload of a single hydraulic protection cylinder in the press.

[0072] Optionally, when the pressure difference at both ends of the main valve damping hole 3117 becomes larger, the main valve spring 3113 pushes the main valve core 3112 to move in the first installation cavity, and the working oil cavity 3115 is connected to the first oil return cavity 3116;

[0073] The main valve body 3111 is provided with an oil unloading port 3118 , one end of which is connected to the first oil return chamber 3116 , and the other end of which is connected to the oil return port through the oil return pipe 5 .

[0074] Specifically, an oil unloading port 3118 can be opened on the main valve body 3111, and one end of the return oil pipe 5 can be connected to the oil unloading port 3118, so that the first return oil chamber 3116 of the main valve structure 311 can be connected to one end of the return oil pipe 5 through the oil unloading port 3118, and the other end of the return oil pipe 5 is connected to the oil return port of the hydraulic station 1.

[0075] In this optional embodiment, the main function of opening the solenoid valve 32 is to increase the pressure difference at both ends of the main valve damping hole 3117, thereby providing a hydraulic thrust for the opening of the main valve structure 311. For example, after the solenoid valve 32 is opened, the hydraulic oil at the working oil chamber 3115 of the main valve structure 311 flows to the second return oil chamber 322 through the main valve damping hole 3117, the second installation chamber, the pilot pressure oil chamber 3126, and the solenoid valve pressure oil chamber 321. At this time, the pressure of the hydraulic oil at one end of the main valve damping hole 3117 of the main valve structure 311 connected to the working oil chamber 3115 becomes The pressure of the hydraulic oil in the main valve damping hole 3117 at the other end of the pilot pressure oil chamber 3126 (or the second installation chamber) becomes larger, so that the pressure difference at both ends of the main valve damping hole 3117 becomes larger, and the main valve core 3112 of the main valve structure 311 is pushed by the hydraulic oil in the pilot pressure oil chamber 3126 to move linearly in the first installation chamber of the main valve body 3111, so that the main valve structure 311 is opened, so that the working oil chamber 3115 of the main valve structure 311 can be directly connected to the first return oil chamber 3116, so as to realize the unloading action of the main valve structure 311.

[0076] Optionally, combined Figure 3 As shown, the hydraulic protection system 100 of the press machine further includes a plurality of one-way valves 7, each of the one-way valves 7 is disposed on the corresponding oil inlet pipe 4, and the one-way valve 7 is used to limit the hydraulic oil of the hydraulic protection cylinder 2 to flow in the reverse direction toward the oil outlet.

[0077] Specifically, the number of the one-way valves 7 can match the number of the oil inlet pipes 4 and the hydraulic protection cylinders 2 , and a one-way valve 7 can be provided on each oil inlet pipe 4 .

[0078] In this optional embodiment, the oil pump of the hydraulic station 1 can pump out hydraulic oil from the hydraulic oil tank and transport it to the hydraulic protection cylinder 2 along the oil inlet pipe 4 through the one-way valve 7, while the hydraulic oil in the working chamber of the hydraulic protection cylinder 2 cannot flow back to the hydraulic station 1 through the one-way valve 7. Therefore, the one-way valve 7 can effectively limit the hydraulic oil of the hydraulic protection cylinder 2 from flowing back to the oil outlet.

[0079] Optionally, combined Figure 3As shown, the pressure detection structure 6 includes a plurality of pressure detection devices 61, and the plurality of pressure detection devices 61 are arranged at intervals on the oil inlet pipe 4, and the plurality of pressure detection devices 61 are used to be configured to have overload pressure values ​​of different levels.

[0080] Specifically, a plurality of pressure detection devices 61 may be provided on each oil inlet pipe 4 connected to the corresponding hydraulic protection oil cylinder 2, and each pressure detection structure 6 may include three pressure detection devices 61 (see Figure 3 As shown), and the overload values ​​set for the multiple pressure detection devices 61 in the pressure detection structure 6 are different. In other words, there is a certain difference in the overload setting values ​​of two adjacent pressure detection devices 61 in the multiple pressure detection devices 61.

[0081] The pressure detection device 61 may be a pressure switch.

[0082] In this optional embodiment, a plurality of pressure detection devices 61 with different overload pressure values ​​can be set on the oil inlet pipe 4 corresponding to each hydraulic protection cylinder 2 (pressure point), and the punching force of the press can be set to different levels of overload. When setting different pressure levels, firstly, the adjusting bolt 3128 of the pilot valve structure 312 is adjusted accordingly according to the actual overload demand to ensure that the unloading of the pilot valve is consistent with the actual required overload pressure, and accordingly ensure that when the pressure of any hydraulic protection cylinder 2 reaches the overload tonnage, it can be automatically unloaded from the pilot valve structure 312. Secondly, when the pressure detection device 61 of the corresponding level sends an overload signal, the hydraulic protection system 100 of the press will control the solenoid valves 32 of the multiple unloading valve groups 3 to open synchronously, and the main valve structures 311 of the multiple unloading valve groups 3 to open synchronously, so as to realize the synchronous unloading function of multiple hydraulic protection cylinders 2.

[0083] The unloading valve group 3 can protect the safety of the transmission mechanism and the mold of the press. The overload pressure values ​​of the multiple pressure detection devices 61 are different, so that the unloading function can be realized for different levels of punching pressure according to actual work requirements, thereby correspondingly expanding the range of workpiece types that the press can punch on the mold.

[0084] Optionally, the hydraulic protection system 100 of the press machine further includes a plurality of pressure gauges 8 , each of the pressure gauges 8 being connected to the corresponding hydraulic protection cylinder 2 for displaying the pressure value of the hydraulic protection cylinder 2 .

[0085] Specifically, a pressure gauge 8 may be configured for each hydraulic protection cylinder 2 , and the pressure gauge 8 may be directly connected to the working chamber of the hydraulic protection cylinder 2 , or be arranged on the pipeline between the hydraulic protection cylinder 2 and the unloading valve group 3 .

[0086] In this optional embodiment, the pressure value (such as oil pressure) of the corresponding hydraulic protection cylinder 2 can be monitored in real time by each pressure gauge 8, and the corresponding pressure reading can be displayed, so that the staff can know the pressure value of each hydraulic protection cylinder 2 when it is working in real time.

[0087] Optionally, the hydraulic protection system 100 of the press also includes a control device, and each of the pressure detection structures 6 is respectively arranged at a position of the corresponding oil inlet pipe 4 close to the hydraulic protection cylinder 2, and the multiple pressure detection structures 6 are respectively electrically connected to the control device, and the control device is electrically connected to the multiple solenoid valves 32, and is used to control the multiple solenoid valves 32 to open simultaneously according to at least one overload signal.

[0088] Specifically, the control device may be a control panel, a controller, etc., and the plurality of pressure detection structures 6 are electrically connected to the signal end of the control device respectively, and the control end of the control device may be electrically connected to the plurality of solenoid valves 32 respectively.

[0089] In this optional embodiment, the pressure of the hydraulic oil at the position of the oil inlet pipe 4 close to the hydraulic protection cylinder 2 is closer to the pressure value of the hydraulic oil in the working chamber of the hydraulic protection cylinder 2. Therefore, each of the pressure detection structures 6 is respectively arranged at the corresponding position of the oil inlet pipe 4 close to the hydraulic protection cylinder 2, thereby ensuring the accuracy of the pressure detection structure 6 in detecting the pressure signal (or overload signal) of the hydraulic protection cylinder 2.

[0090] Since the multiple pressure detection structures 6 are electrically connected to the control device respectively, and the control device is electrically connected to the multiple solenoid valves 32, when an overload signal appears in at least one of the multiple hydraulic protection cylinders 2, the corresponding pressure detection structure 6 can transmit the overload signal to the control device, and the control device controls the solenoid valves 32 of the multiple unloading valve groups 3 to open simultaneously for unloading, thereby ensuring the working safety of the transmission mechanism and the mold of the press.

[0091] The hydraulic protection system 100 of the press can adopt the following working process, for example, in combination with Figure 7 As shown, the hydraulic oil in the hydraulic station 1 can be transported to the working chamber of the hydraulic protection cylinder 2 through the oil inlet pipe 4. At this time, part of the hydraulic oil can be in the working oil chamber 3115 of the main valve structure 311. The pressure of the entire hydraulic protection system 100 is normal, and the main valve structure 311, the pilot valve structure 312 and the solenoid valve 32 are all in the off state.

[0092] Combination Figure 8As shown, when the pressure of any hydraulic protection cylinder 2 reaches the set overload pressure, the pressure detection structure 6 detects an overload signal, and at the same time, the pilot valve core 3122 of the corresponding overload protection valve 31 that generates the overload signal opens under the action of the hydraulic oil, so that the hydraulic oil of the hydraulic protection cylinder 2 flows through the working oil chamber 3115, the main valve damping hole 3117, the pilot pressure oil chamber 3126, the third installation chamber 3125, the pilot oil unloading oil chamber 3127, the first return oil chamber 3116 of the main valve structure 311, the oil unloading port 3118, and the return oil pipe 5 to overflow back to the hydraulic oil tank of the hydraulic station 1. Since the flow through the main valve damping hole 3117 is very small, the pressure difference before and after the main valve damping hole 3117 is very small, and the main valve core 3112 and the solenoid valve 32 are not opened at this time and are both in the off state.

[0093] Combination Fig. 9 As shown, the pressure detection device 61 can send the detected overload signal to the solenoid valve 32 via the control device, and the solenoid valves 32 corresponding to the hydraulic protection cylinders 2 at all four locations are all opened. At the same time, the pilot valve core 3122 of the corresponding overload protection valve 31 that generates the overload signal is opened under the action of the hydraulic oil, so that the hydraulic oil of the hydraulic protection cylinder 2 is sequentially returned to the hydraulic oil tank of the hydraulic station 1 through the working oil chamber 3115, the main valve damping hole 3117, the pilot pressure oil chamber 3126, the solenoid valve pressure oil chamber 321, the second return oil chamber 322, the first return oil chamber 3116 of the main valve structure 311, the oil unloading port 3118, and the return oil pipe 5. At this time, the pressure difference before and after the main valve damping hole 3117 (for example, the working oil chamber 3115 and the pilot pressure oil chamber 3126) becomes larger.

[0094] Combination Fig.10 As shown, the pressure difference before and after the main valve damping hole 3117 becomes larger, and the main valve core 3112 is fully opened under the action of the pressure difference, so that the high-pressure hydraulic oil in the working oil chamber 3115 of the main valve structure 311 is quickly returned to the hydraulic station 1 through the first return oil chamber 3116, the oil unloading port 3118, and the return oil pipe 5 in sequence, so that the system pressure is unloaded, completing the protection function of the press equipment.

[0095] Subsequently, after the unloading is completed, the main valve core 3112 and the pilot valve core 3122 are automatically reset under the action of the main valve spring 3113 and the pilot spring 3123 respectively, and the solenoid valve 32 is reset manually.

[0096] Finally, after completing the overload condition inspection, the hydraulic protection cylinder and the working oil chamber are filled with pre-pressed hydraulic oil through the hydraulic station, the overload protection valve completes the reset process, and the press can work normally.

[0097] in, Figures 4 to 10 The multiple black dots in the overload protection valve 31 are hydraulic oil.

[0098] A press provided by an embodiment of the present invention includes the hydraulic protection system 100 of the press as described in the above embodiment.

[0099] Combination Fig.11 As shown, the press in this embodiment also includes an upper beam 200, a transmission mechanism 700, a column 400, a slider 300, a workbench 500 and a base 600, wherein the base 600 can be installed on a supporting surface such as the ground, the workbench 500 is installed on the base 600, a mold can be installed on the workbench 500, and the mold is used to place the workpiece to be stamped. A plurality of columns 400 are installed on the base 600 and are located on the side of the workbench 500. The upper beam 200 is connected to the top ends of the plurality of columns 400 to support the upper beam 200 through the columns 400. The fixed ends of the plurality of hydraulic protection cylinders 2 can be installed on the slider 300, and the piston rods of the plurality of hydraulic protection cylinders 2 are upward and connected to the transmission mechanism 700 of the press. The hydraulic station 1 can be installed on the slider 300, and the piston rod of the hydraulic protection cylinder 2 drives the slider 300 to move up and down through the transmission mechanism 700 of the press to perform stamping operations on the workpiece on the workbench 500. The transmission mechanism 700 may be a transmission device with a deceleration function composed of a gear box and a connecting rod, which is a prior art and is not specifically limited here.

[0100] The beneficial effects of the press of this embodiment relative to the prior art are the same as those of the hydraulic protection system 100 of the press described above, and will not be described in detail here.

[0101] 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 protection system for a press, characterized in that: The invention comprises a hydraulic station (1), a plurality of oil inlet pipes (4), a plurality of oil return pipes (5), a plurality of hydraulic protection cylinders (2), a plurality of pressure detection structures (6) and a plurality of unloading valve groups (3), wherein the hydraulic station (1) has an oil outlet and an oil return port, and the two ends of each of the oil inlet pipes (4) are respectively connected to the oil outlet and the corresponding hydraulic protection cylinder (2), and the unloading valve group (3) comprises an overload protection valve (31) and a solenoid valve (32), and the overload protection valve (31) comprises a working oil chamber (3115) and a first oil return chamber (3116), wherein the working oil chamber (3115) is connected to the corresponding hydraulic protection cylinder (2), and the first oil return chamber (3116) is connected to the oil return port through the corresponding oil return pipe (5); The pressure detection structure (6) is used to detect the overload signal of the corresponding hydraulic protection cylinder (2); the pressure detection structure (6) is electrically connected to the solenoid valve (32); a plurality of the solenoid valves (32) are used to be opened simultaneously according to at least one of the overload signals; the solenoid valve (32) comprises a solenoid valve pressure oil chamber (321) and a second oil return chamber (322); the solenoid valve pressure oil chamber (321) is connected to the working oil chamber (3115); the second oil return chamber (322) is connected to the oil return port via the oil return pipe (5).

2. The hydraulic protection system for a press according to claim 1, characterized in that: The overload protection valve (31) comprises a main valve structure (311), the main valve structure (311) comprises a main valve body (3111), a main valve core (3112), a main valve spring (3113) and a first screw plug (3114), the main valve body (3111) is provided with a first installation cavity inside, the main valve core (3112) is arranged in the first installation cavity; the main valve core (3112) is provided with a second installation cavity inside, a part of the main valve spring (3113) is arranged in the second installation cavity, and another part of the main valve spring (3113) is in the first installation cavity; The main valve body (3111) is provided with the working oil chamber (3115) and the first oil return chamber (3116) inside; the first screw plug (3114) is arranged in the main valve core (3112), and the first screw plug (3114) has a main valve damping hole (3117), and one end of the main valve damping hole (3117) is connected to the working oil chamber (3115).

3. The hydraulic protection system for a press machine according to claim 2, characterized in that: The overload protection valve (31) further comprises a pilot valve structure (312), the pilot valve structure (312) comprising a pilot valve body (3121), a pilot valve core (3122) and a pilot spring (3123), a third installation cavity (3125) being provided inside the pilot valve body (3121), the pilot valve core (3122) and the pilot spring (3123) being arranged in the third installation cavity (3125) of the pilot valve body (3121), and the pilot spring (3123) being sleeved on the pilot valve core (3122); The pilot valve body (3121) has a pilot pressure oil chamber (3126) and a pilot oil unloading chamber (3127); the other end of the main valve damping hole (3117) is connected to the pilot oil unloading chamber (3127) via the pilot pressure oil chamber (3126) and the third installation chamber (3125) in sequence; and the pilot oil unloading chamber (3127) is connected to the first oil return chamber (3116).

4. The hydraulic protection system for a press machine according to claim 2, characterized in that: When the solenoid valve (32) is opened, The second oil return chamber (322) of the solenoid valve (32) is connected to the oil return pipe (5) via the first oil return chamber (3116); or, a connecting flow channel (3119) is provided on the main valve body (3111), and the second oil return chamber (322) of the solenoid valve (32) is connected to the oil return pipe (5) via the connecting flow channel (3119).

5. The hydraulic protection system for a press machine according to any one of claims 2 to 4, characterized in that: When the pressure difference between the two ends of the main valve damping hole (3117) increases, the main valve spring (3113) pushes the main valve core (3112) to move in the first installation cavity, and the working oil cavity (3115) is connected to the first oil return cavity (3116); The main valve body (3111) is provided with an oil unloading port (3118), one end of the oil unloading port (3118) is connected to the first oil return chamber (3116), and the other end of the oil unloading port (3118) is connected to the oil return port through the oil return pipe (5).

6. The hydraulic protection system for a press machine according to claim 1, characterized in that: It also includes a plurality of one-way valves (7), each of the one-way valves (7) being arranged on each of the corresponding oil inlet pipes (4), and the one-way valves (7) being used to limit the hydraulic oil of the hydraulic protection cylinder (2) to flow in the opposite direction toward the oil outlet.

7. The hydraulic protection system for a press machine according to claim 1, characterized in that: The pressure detection structure (6) comprises a plurality of pressure detection devices (61), wherein the plurality of pressure detection devices (61) are arranged at intervals on the oil inlet pipe (4), and the plurality of pressure detection devices (61) are configured to have overload pressure values ​​of different levels.

8. The hydraulic protection system for a press machine according to claim 1, characterized in that: It also comprises a plurality of pressure gauges (8), each of the pressure gauges (8) being connected to the corresponding hydraulic protection cylinder (2) and being used to display the pressure value of the corresponding hydraulic protection cylinder (2).

9. The hydraulic protection system for a press machine according to claim 1, characterized in that: It also includes a control device, each of the pressure detection structures (6) is respectively arranged at a position of the corresponding oil inlet pipe (4) close to the hydraulic protection cylinder (2), and the plurality of pressure detection structures (6) are respectively electrically connected to the control device, and the control device is electrically connected to the plurality of solenoid valves (32) for controlling the plurality of solenoid valves (32) to open simultaneously according to at least one of the overload signals.

10. A press machine, characterized in that: A hydraulic protection system (100) for a press comprising the method according to any one of claims 1 to 9.

Images