Hydraulic protection system of press machine and press machine

Abstract

The utility model 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 groups, 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 machine is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of press equipment, and particularly relates to a hydraulic protection system of press and press. BACKGROUND

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

[0003] The press commonly used for the current automobile covering piece stamping line is generally a closed four-point press, in other words, the overload protection system of the press mainly includes a hydraulic oil tank, four hydraulic protection oil cylinders and a gas-liquid type overload protection valve, the four hydraulic protection oil cylinders can be matched with the slide block of the press to carry out stamping work on the automobile covering piece on the die, and the four pressure points (hydraulic protection oil cylinders) of the press share one overload protection valve (that is, the working oil chambers of the four pressure points are interconnected and connected to the hydraulic oil tank through a high-pressure oil path via the gas-liquid type overload protection valve), and the gas-liquid type overload protection valve will only be unloaded when the total tonnage of the four pressure points exceeds the set value.

[0004] However, in the actual work of the press, due to partial load or other unexpected situations, a single pressure point may be overloaded while the overall load does not reach the overload tonnage, in which case the above-mentioned gas-liquid type overload protection valve will not act, and as the pressure of the overloaded pressure point gradually increases, it is easy to cause damage to the transmission mechanism of the press, the die and the like, thereby greatly reducing the service life of the press. UTILITY MODEL CONTENTS

[0005] The problem solved by the utility model is how to avoid the overload of a single hydraulic protection oil cylinder in the press without unloading action, so as to avoid damage to the transmission mechanism of the press and the die.

[0006] To solve the above-mentioned problems, the utility model provides a hydraulic protection system of press and press.

[0007] In the first aspect, the utility model provides a hydraulic protection system of press, including hydraulic station, multiple oil inlet pipes, multiple oil return pipes, multiple hydraulic protection oil cylinders, multiple pressure detection structures and multiple unloading valve groups, the hydraulic station has oil outlet and oil return, two ends of each oil inlet pipe are connected with oil outlet and corresponding hydraulic protection oil cylinder respectively, the unloading valve group includes overload protection valve and electromagnetic valve, the overload protection valve includes working oil chamber and first oil return chamber, the working oil chamber is connected with corresponding hydraulic protection oil cylinder, the first oil return chamber is connected with oil return through corresponding oil return pipe;

[0008] The pressure detection structure is used for detecting overload signals of the corresponding hydraulic protection oil cylinder, and is electrically connected with the electromagnetic valve; the plurality of electromagnetic valves are used for being opened simultaneously according to at least one overload signal; the electromagnetic valve comprises an electromagnetic valve pressure oil cavity and a second return oil cavity, the electromagnetic valve pressure oil cavity is communicated with the working oil cavity, and the second return oil cavity is communicated with the return oil port through the return oil 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, an inner portion of the main valve body is provided with a first installation cavity, and the main valve core is arranged in the first installation cavity; an inner portion of the main valve core is provided with a second installation cavity, a part of the main valve spring is arranged in the second installation cavity, and another part of the main valve spring is arranged in the first installation cavity.

[0010] The inner portion of the main valve body is provided with the working oil cavity and the first return oil cavity; the first screw plug is arranged in the main valve core, and the first screw plug is provided with a main valve damping hole, one end of the main valve damping hole is communicated with the working oil cavity.

[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, an inner portion of the pilot valve body is provided with a third installation cavity, and 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 is provided with a pilot pressure oil cavity and a pilot oil discharge cavity, and the other end of the main valve damping hole is communicated with the pilot oil discharge cavity in sequence through the pilot pressure oil cavity and the third installation cavity, and the pilot oil discharge cavity is communicated with the first return oil cavity.

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

[0014] The second return oil cavity of the electromagnetic valve is communicated with the return oil pipe through the first return oil cavity, or the main valve body is provided with a communication flow channel, and the second return oil cavity of the electromagnetic valve is communicated with the return oil pipe through the communication flow channel.

[0015] Optionally, when the pressure difference between the two ends of the main valve damping hole becomes large, the main valve spring pushes the main valve core to move in the first installation cavity, and the working oil cavity is communicated with the first return oil cavity.

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

[0017] Optionally, the hydraulic protection system of the press further comprises a plurality of one-way valves, each of the one-way valves is arranged on a corresponding one of the oil inlet pipes, and the one-way valves are configured to limit the reverse flow of the hydraulic oil of the hydraulic protection oil cylinders to the oil outlet.

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

[0019] Optionally, the hydraulic protection system of the press further comprises a plurality of pressure gauges, each of the pressure gauges is in communication with a corresponding one of the hydraulic protection oil cylinders, and the pressure gauges are configured to display the pressure values of the corresponding hydraulic protection oil cylinders.

[0020] Optionally, the hydraulic protection system of the press further comprises a control device, each of the pressure detection structures is arranged at a position close to the corresponding hydraulic protection oil cylinder on the corresponding oil inlet pipe, the plurality of pressure detection structures are electrically connected to the control device, the control device is electrically connected to the plurality of electromagnetic valves, and the control device is configured to control the plurality of electromagnetic valves to be opened simultaneously according to at least one of the overload signals.

[0021] In a second aspect, the utility model provides a kind of press, including the hydraulic protection system of the press as described above.

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

[0023] The hydraulic protection system of the press can include a plurality of hydraulic protection oil cylinders, and the oil outlet of the hydraulic station is connected to the corresponding hydraulic protection oil cylinder through a plurality of oil inlet pipes, so that the hydraulic station can deliver hydraulic oil to the hydraulic protection oil cylinder through the oil inlet pipe via the oil outlet, to provide hydraulic power for the work of the hydraulic protection oil cylinder.

[0024] One pressure detection structure and unloading valve group can be configured for each hydraulic protection oil cylinder, when at least one pressure detection structure detects an overload signal of the corresponding hydraulic protection oil cylinder, the overload protection valve in the unloading valve group corresponding to the hydraulic protection oil cylinder where the overload signal occurs is actively opened under the action of the hydraulic oil pressure in the hydraulic protection oil cylinder, so that the hydraulic oil in the hydraulic protection oil cylinder where the overload signal occurs is unloaded into the hydraulic oil tank of the hydraulic station in turn through the working oil chamber of the overload protection valve, the first return oil chamber, the return oil pipe and the return oil outlet, to realize the active unloading operation of the hydraulic protection oil cylinder where the overload signal occurs.

[0025] Meanwhile, the pressure detection structure also sends the overload signal to the pressure detection structure corresponding to other hydraulic protection oil cylinders, and no matter whether the pressure of the unloading valve group corresponding to other hydraulic protection oil cylinders reaches the unloading pressure, the electromagnetic valve of all unloading valve groups will be opened at the same time to actively unload according to the overload signal of the pressure detection structure, and since the electromagnetic valve pressure oil cavity and the second return oil cavity of the electromagnetic valve are respectively communicated with the working oil cavity and the first return oil cavity of the corresponding overload protection valve, the hydraulic oil in each hydraulic protection oil cylinder sequentially passes through the working oil cavity of the overload protection valve, the electromagnetic valve pressure oil cavity and the second return oil cavity of the electromagnetic valve, the return oil pipe and the return oil port to unload into the hydraulic oil tank of the hydraulic station, so as to realize the unloading operation of all hydraulic protection oil cylinders of the press, effectively avoid the damage of the transmission mechanism and the die of the whole press caused by the single hydraulic protection oil cylinder (pressure point) of the press being overloaded without reaching the overload tonnage, and ensure the safety of the press, and accordingly prolong the service life of the press. BRIEF DESCRIPTION OF DRAWINGS

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

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

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

[0029] Figure 4 It is a principle structure diagram of unloading valve group in the embodiment of the utility model.

[0030] Figure 5 It is a principle structure diagram of flow path of hydraulic oil when the electromagnetic valve is opened.

[0031] Figure 6 It is a principle structure diagram of flow path of hydraulic oil when the electromagnetic valve is opened.

[0032] Figure 7 It is a principle structure diagram of system pressure of hydraulic protection system in the embodiment of the utility model.

[0033] Figure 8 It is an unloading principle structure diagram when the pressure of certain pressure point reaches the set overload pressure in the embodiment of the utility model.

[0034] Figure 9 It is an unloading principle structure diagram when the electromagnetic valve is opened.

[0035] Figure 10The unloading principle structure diagram that the main valve structure opens in the embodiment of the utility model.

[0036] Figure 11 The structure schematic diagram of the press machine in the embodiment of the utility model.

[0037] Mark explanation:

[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 oil 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 cavity;3116-first oil return cavity;3117-main valve damping hole;3118-oil discharge port;3119-communication flow channel;312-pilot valve structure;3121-pilot valve body;3122-pilot valve core;3123-pilot spring;3124-second screw plug;3125-third installation cavity;3126-pilot pressure oil cavity;3127-pilot oil discharge oil cavity;3128-adjusting bolt;32-solenoid valve;321-solenoid valve pressure oil cavity;322-second oil return cavity;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-sliding block;400-stand;500-workbench;600-base;700-transmission mechanism. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purpose, features and advantages of the utility model more obvious and easy to understand, the specific embodiments of the utility model are described in detail below with reference to the drawings. Although some embodiments of the utility model are shown in the drawings, it should be understood that the utility model can be realized in various forms, and should not be interpreted as being limited to the embodiments described herein, on the contrary, these embodiments are provided to more thoroughly and completely understand the utility model. It should be understood that the drawings and embodiments of the utility model are only for exemplary purposes, and are not used to limit the protection scope of the utility model.

[0041] The term "include" and variations thereof, as used in this document, is open-ended, that is, it means "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 additional embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optional" means "optional in at least some embodiments". Related terms shall be construed accordingly. It should be noted that "a" or "an" entity as used herein means "one or more" of that entity; the use of the term "at least one" followed by a list of entities means "one or more of the listed entities, and that different ones of the listed entities can be used in different instances. It is further noted that the use of "a" or "an" should be interpreted to mean "one or more" unless explicitly stated otherwise.

[0042] It should be noted that the modification of "one" or "multiple" mentioned in the present application is illustrative rather than restrictive, and those skilled in the art should understand that unless otherwise explicitly stated 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] The press commonly used in the current automobile panel stamping line is usually a closed four-point press, in other words, combined with Figure 1 As shown in the figure, the overload protection system of the press mainly includes a hydraulic oil tank 1', four oil cylinders 2', a high-pressure oil way 4' and a gas-liquid overload protection valve 3'. The four hydraulic protection oil cylinders 2' can cooperate with the slide block of the press to perform stamping work on the automobile panel on the die. The four pressure points (hydraulic protection oil cylinders 2') of this type of press share one overload protection valve (that is, the working oil chambers of the four pressure points are connected to each other and connected to the hydraulic oil tank 1' through the high-pressure oil way 4' via the gas-liquid overload protection valve 3'), and the gas-liquid overload protection valve 3' will only act when the total tonnage of the four pressure points exceeds the set value.

[0045] However, in the actual work of the press, due to unbalanced load or other unexpected situations, it may occur that only one pressure point is overloaded while the overall load does not reach the overload tonnage. In this case, the above-mentioned gas-liquid overload protection valve 3' will not act, and as the pressure of the overloaded pressure point gradually increases, it is easy to cause damage to the transmission mechanism, die and other parts of the press, thereby greatly reducing the service life of the press.

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

[0047] As Figure 2 and Figure 3As shown, the hydraulic protection system of the press provided by the embodiment of the utility model, including hydraulic station 1, multiple oil inlet pipe 4, multiple oil return pipe 5, multiple hydraulic protection oil cylinder 2, multiple pressure detection structure 6 and multiple unloading valve group 3, the hydraulic station 1 has oil outlet and oil return, the both ends of each oil inlet pipe 4 are communicated oil outlet and corresponding hydraulic protection oil cylinder 2 respectively, the unloading valve group 3 includes overload protection valve 31 and electromagnetic valve 32, the overload protection valve 31 includes working oil cavity 3115 and first oil return cavity 3116, the working oil cavity 3115 is communicated corresponding hydraulic protection oil cylinder 2, the first oil return cavity 3116 is communicated oil return through corresponding oil return pipe 5,

[0048] The pressure detection structure 6 is used for detecting the overload signal of the corresponding hydraulic protection oil cylinder 2, and the pressure detection structure 6 is electrically connected with the electromagnetic valve 32, and the plurality of electromagnetic valves 32 are used for being opened simultaneously according to at least one overload signal; the electromagnetic valve 32 includes an electromagnetic valve pressure oil cavity 321 and a second oil return cavity 322, the electromagnetic valve pressure oil cavity 321 is communicated with the working oil cavity 3115, and the second oil return cavity 322 is communicated with the oil return through the oil return pipe 5.

[0049] Specifically, the hydraulic station 1 at least includes an oil pump and a hydraulic oil tank, the input end of the oil pump is communicated with the hydraulic oil tank, the output end of the oil pump has the oil outlet, the oil outlet is communicated with the hydraulic protection oil cylinder 2 through the oil inlet pipe 4; the first oil return cavity 3116 of the overload protection valve 31 and the second oil return cavity 322 of the electromagnetic valve 32 can be respectively communicated with one end of the oil return pipe 5, the hydraulic oil tank has the oil return, and the other end of the oil return pipe 5 is communicated with the oil return.

[0050] In the embodiment, the press can include a plurality of hydraulic protection oil cylinders 2, and the oil outlet of the hydraulic station 1 is communicated with the corresponding hydraulic protection oil cylinder 2 through a plurality of oil inlet pipes 4, so that the hydraulic station 1 can deliver hydraulic oil to the hydraulic protection oil cylinder 2 through the oil outlet and the oil inlet pipe 4, to provide hydraulic power for the work of the hydraulic protection oil cylinder 2.

[0051] One pressure detection structure 6 and unloading valve group 3 can be configured for each hydraulic protection oil cylinder 2, when at least one pressure detection structure 6 detects that the corresponding hydraulic protection oil cylinder 2 appears overload signal, at this time, the overload signal appears in the hydraulic protection oil cylinder 2, and the overload protection valve 31 in the unloading valve group 3 corresponding to the hydraulic protection oil cylinder 2 is actively opened under the action of the hydraulic oil pressure in the hydraulic protection oil cylinder 2, so that the hydraulic oil in the hydraulic protection oil cylinder 2 where the overload signal appears is sequentially discharged to the hydraulic oil tank of the hydraulic station 1 through the working oil cavity 3115 of the overload protection valve 31, the first oil return cavity 3116, the oil return pipe 5 and the oil return, to realize the active unloading operation of the hydraulic protection oil cylinder 2 where the overload signal appears.

[0052] Meanwhile, the overload signal is also sent to the pressure detection structure 6 corresponding to the other hydraulic protection oil cylinder 2, and the electromagnetic valve 32 of all the unloading valve groups 3 will be opened simultaneously to actively unload, regardless of whether the pressure reaches the unloading pressure, because the electromagnetic valve pressure oil chamber 321 and the second return oil chamber 322 of the electromagnetic valve 32 are respectively connected to the working oil chamber 3115 and the first return oil chamber 3116 of the corresponding overload protection valve 31, so that the hydraulic oil in each hydraulic protection oil cylinder 2 passes through the working oil chamber 3115 of the overload protection valve 31, the electromagnetic valve pressure oil chamber 321 and the second return oil chamber 322 of the electromagnetic valve 32, the return oil pipe 5, and the return oil port to the hydraulic oil tank of the hydraulic station 1 in turn, so as to realize the unloading operation of all the hydraulic protection oil cylinders 2 of the press, effectively avoid the damage of the transmission mechanism and the die of the entire press caused by the single hydraulic protection oil cylinder 2 (pressure point) of the press being overloaded while the overall overload tonnage is not reached, so as to ensure the safe operation of the press and prolong the service life of the press.

[0053] Optionally, in combination with Figure 4 As shown, 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 inside of the main valve body 3111 is provided with a first installation cavity, and the main valve core 3112 is arranged in the first installation cavity; the inside of the main valve core 3112 is provided with a second installation cavity, a part of the main valve spring 3113 is arranged in the second installation cavity, and the other part of the main valve spring 3113 is in the first installation cavity.

[0054] The inside of the main valve body 3111 is provided with the working oil chamber 3115 and the first return oil chamber 3116; 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, one end of the main valve damping hole 3117 is communicated with the working oil chamber 3115.

[0055] Specifically, the main valve core 3112 can be connected with the main valve body 3111 by the following way, for example, a first installation cavity can be arranged in the inside of the main valve body 3111, and the main valve core 3112 is arranged in the first installation cavity of the main valve body 3111. Wherein, the dimension of the main valve core 3112 along the axial direction thereof is smaller than the dimension of the first installation cavity, so as to provide a moving space for the main valve core 3112 to open the main valve structure 311 in the first installation cavity.

[0056] The main valve spring 3113 can be connected with the main valve core 3112 by the following ways, for example, a second installation cavity can be arranged in the inside of the main valve core 3112, 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 with 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 with the inner wall of the second installation cavity

[0057] The main valve body 3111 is provided with a first oil return cavity 3116 outside the main valve core 3112, and the main valve body 3111 can be provided with a working oil cavity 3115 near the position of the hydraulic protection oil cylinder 2, which can be communicated with the working cavity of the hydraulic protection oil cylinder 2.

[0058] A first installation groove can be arranged at the position of the main valve core 3112 towards the working oil cavity 3115, and the first screw plug 3114 is installed in the first installation groove, and the first screw plug 3114 has a main valve damping hole, one end of the main valve damping hole 3117 can be communicated with the working oil cavity 3115, and the other end can be communicated with the electromagnetic valve pressure oil cavity 321 through the second installation cavity of the main valve core 3112.

[0059] In this optional embodiment, since one end of the main valve damping hole 3117 is communicated with the working oil cavity 3115, and the other end is communicated with the electromagnetic valve pressure oil cavity 321, when the electromagnetic valve 32 is opened, the hydraulic oil in the working cavity of the hydraulic protection oil cylinder 2 flows back to the hydraulic station 1 through the working oil cavity 3115, the main valve damping hole 3117, the electromagnetic valve pressure oil cavity 321, the second oil return cavity 322, the first oil return cavity 3116 and the oil return pipe 5 in turn, so as to not only realize the unloading action, but also make the pressure difference between the two ends of the main valve damping hole 3117 larger as the pressure of the working oil cavity 3115 of the main valve body 3111 becomes smaller, so that the pressure of the hydraulic oil at the electromagnetic valve pressure oil cavity 321 is greater than the force of the main valve spring 3113, so as to drive the main valve core 3112 to move in the first installation cavity of the main valve body 3111 through the main valve spring 3113, so as to open the main valve structure 311, which helps the hydraulic oil in the working oil cavity 3115 of the main valve body 3111 to be unloaded to the hydraulic station 1 as soon as possible, and correspondingly improves the unloading effect of the hydraulic oil.

[0060] Optionally, in combination with Figure 4As shown, the overload protection valve 31 further comprises a pilot valve structure 312, which comprises a pilot valve body 3121, a pilot valve spool 3122 and a pilot spring 3123, the interior of the pilot valve body 3121 is provided with a third mounting cavity 3125, the pilot valve spool 3122 and the pilot spring 3123 are arranged in the third mounting cavity 3125 of the pilot valve body 3121, and the pilot spring 3123 is sleeved on the pilot valve spool 3122.

[0061] The pilot valve body 3121 is provided with a pilot pressure oil cavity 3126 and a pilot unloading oil cavity 3127, the other end of the main valve damping hole 3117 is communicated with the pilot unloading oil cavity 3127 through the pilot pressure oil cavity 3126 and the third mounting cavity 3125 in sequence, and the pilot unloading oil cavity 3127 is communicated with the first return oil cavity 3116.

[0062] Specifically, the pilot valve body 3121 can be connected with the main valve body 3111 to realize the assembly of the pilot valve structure 312 and the main valve structure 311; the pilot valve spool 3122 can be connected with the pilot valve body 3121 by means of, for example, arranging the third mounting cavity 3125 in the interior of the pilot valve body 3121, and arranging the pilot valve spool 3122 and the pilot spring 3123 in the third mounting cavity 3125 of the pilot valve body 3121. Wherein, the dimension of the pilot valve spool 3122 along the axial direction thereof is smaller than the dimension of the third mounting cavity 3125, thereby providing a moving space for the pilot valve spool 3122 to open the pilot valve structure 312 in the third mounting cavity 3125.

[0063] The pilot spring 3123 can be connected with the pilot valve spool 3122 by means of, for example, sleeving the pilot spring 3123 on the pilot valve spool 3122; wherein, the axis of the pilot spring 3123 can coincide with the axis of the pilot valve spool 3122.

[0064] The pilot valve structure 312 further comprises a second screw plug 3124 and an adjusting screw 3128, since the interior of the pilot valve body 3121 needs to be machined to form the third mounting cavity 3125, the opposite ends of the pilot valve body 3121 at the positions corresponding to the third mounting cavity 3125 are respectively provided with machining holes, and the second screw plug 3124 can be arranged at one machining hole. The adjusting screw 3128 can be arranged at the other machining hole of the pilot valve body 3121 by means of threads, and the bottom end of the adjusting screw 3128 can be connected with the pilot valve spool 3122, and the pressure of the pilot spring 3123 sleeved on the outside of the pilot valve spool 3122 can be adjusted by rotating the adjusting screw 3128, thereby adjusting the overload pressure of the pilot valve structure 312.

[0065] The pilot pressure oil cavity 3126 is formed in the pilot valve body 3121 at a position corresponding to the second mounting cavity in the main valve structure 311, and the main valve damping hole 3117 communicates with the pilot pressure oil cavity 3126 through the second mounting cavity; the pilot unloading oil cavity 3127 is arranged between the third mounting cavity 3125 of the pilot valve body 3121 and the first return oil cavity 3116 of the main valve body 3111, in other words, the third mounting cavity 3125 in the pilot valve body 3121 communicates with the first return oil cavity 3116 of the main valve body 3111 through the pilot unloading oil cavity 3127.

[0066] In the optional embodiment, the other end of the main valve damping hole 3117 communicates with the pilot pressure oil cavity 3126, the third mounting cavity 3125 and the pilot unloading oil cavity 3127 in sequence, and the pilot unloading oil cavity 3127 communicates with the first return oil cavity 3116, so that when the hydraulic protection oil cylinder 2 just starts to generate an overload signal, the hydraulic oil in the hydraulic protection oil cylinder 2 can flow from the main valve damping hole 3117 of the main valve structure 311 to the first return oil cavity 3116 in the main valve body 3111 through the second mounting cavity, the pilot pressure oil cavity 3126 of the pilot valve structure 312, the third mounting cavity 3125 and the pilot unloading oil cavity 3127 in sequence, and the first return oil cavity 3116 communicates with the hydraulic station 1 through the return oil pipe 5, so that the hydraulic oil in the first return oil cavity 3116 flows back to the hydraulic station 1 through the return oil pipe 5, thereby realizing unloading action.

[0067] Optionally, in combination with Figure 5 and Figure 6 It is shown that the main valve structure 311 has two different structural modes, when the electromagnetic valve 32 is opened,

[0068] One is that the second return oil cavity 322 of the electromagnetic valve 32 communicates with the return oil pipe 5 through the first return oil cavity 3116; or, the other is that the main valve body 3111 is provided with a communication flow channel 3119, and the second return oil cavity 322 of the electromagnetic valve 32 communicates with the return oil pipe 5 through the communication flow channel 3119.

[0069] Specifically, when the electromagnetic valve 32 is opened, the hydraulic oil unloads to the hydraulic station 1 through the electromagnetic valve 32, which can be selected from one of the following two paths, for example, in combination with Figure 5As shown, the main valve damping hole 3117 is communicated with the second mounting cavity, the pilot pressure oil cavity 3126, the electromagnetic valve pressure oil cavity 321 of the electromagnetic valve 32, the second return oil cavity 322, the first return oil cavity 3116 of the main valve structure 311 in turn, and the oil return pipe 5; so that in the case of opening of the electromagnetic valve, the hydraulic oil of the hydraulic protection oil cylinder 2 can flow to the pilot pressure oil cavity 3126 through the main valve damping hole 3117 and the second mounting cavity in turn, at this time, the hydraulic oil is branched, most of the hydraulic oil flows to the first return oil cavity 3116 of the main valve structure 311 through the electromagnetic valve pressure oil cavity 321 of the electromagnetic valve 32 and the second return oil cavity 322, and the other part of the hydraulic oil flows into the first return oil cavity 3116 through the third mounting cavity 3125 of the pilot valve body 3121 and the pilot unloading oil cavity 3127, and finally the hydraulic oil in the first return oil cavity 3116 is unloaded to the hydraulic oil tank of the hydraulic station 1 through the oil return pipe 5.

[0070] Alternatively, in combination with Figure 6 As shown, the main valve body 3111 is provided with a communication flow channel 3119 for communicating the second return oil cavity 322 and the oil return pipe 5; the main valve damping hole 3117 is communicated with the second mounting cavity, the pilot pressure oil cavity 3126, the electromagnetic valve pressure oil cavity 321 of the electromagnetic valve 32, the second return oil cavity 322, the communication flow channel 3119, and the oil return pipe 5, in other words, the communication flow channel 3119 is different from the unloading port of the first return oil cavity 3116, so that the communication flow channel 3119 and the first return oil cavity 3116 can be communicated with the oil return port of the hydraulic station through different oil return pipes.

[0071] Wherein, the hydraulic oil of the hydraulic protection oil cylinder 2 can be branched through the main valve damping hole 3117 and the second mounting cavity to flow to the pilot pressure oil cavity 3126, most of the hydraulic oil is unloaded to the hydraulic oil tank of the hydraulic station 1 through the electromagnetic valve pressure oil cavity 321 of the electromagnetic valve 32, the second return oil cavity 322, the communication flow channel 3119, and the oil return pipe 5, and the other part of the hydraulic oil is unloaded to the hydraulic oil tank of the hydraulic station 1 through the third mounting cavity 3125 of the pilot valve body 3121, the pilot unloading oil cavity 3127, the first return oil cavity 3116, and the other oil return pipe 5, in short, the hydraulic oil of the above two different flow paths is unloaded from different 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 oil cylinder, and effectively avoid the expansion of the failure caused by the overload of a single hydraulic protection oil cylinder in the press.

[0072] Optionally, when the pressure difference between the two ends of the main valve damping hole 3117 becomes large, the main valve spring 3113 pushes the main valve core 3112 to move in the first mounting cavity, and the working oil cavity 3115 communicates with the first return oil cavity 3116;

[0073] The main valve body 3111 is provided with an oil discharge port 3118, one end of the oil discharge port 3118 is communicated with the first oil return cavity 3116, and the other end of the oil discharge port 3118 is communicated with the oil return port through the oil return pipe 5.

[0074] Specifically, the oil discharge port 3118 can be formed on the main valve body 3111, and one end of the oil return pipe 5 can be communicated with the oil discharge port 3118, so that the first oil return cavity 3116 of the main valve structure 311 can be communicated with one end of the oil return pipe 5 through the oil discharge port 3118, and the other end of the oil return pipe 5 is communicated with the oil return port of the hydraulic station 1.

[0075] In this optional embodiment, the main function of the electromagnetic valve 32 is to increase the pressure difference between the two ends of the main valve damping hole 3117, thereby providing hydraulic thrust for the opening of the main valve structure 311. For example, after the electromagnetic valve 32 is opened, the hydraulic oil at the working oil cavity 3115 of the main valve structure 311 flows through the main valve damping hole 3117, the second mounting cavity, the pilot pressure oil cavity 3126, the electromagnetic valve pressure oil cavity 321 to the second oil return cavity 322, 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 becomes smaller, and the pressure of the hydraulic oil at the other end of the main valve damping hole 3117 of the main valve structure 311 becomes larger, so that the pressure difference between the two 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 cavity 3126 to move linearly in the first mounting cavity of the main valve body 3111, so that the main valve structure 311 is opened, and the working oil cavity 3115 of the main valve structure 311 is directly communicated with the first oil return cavity 3116, to realize the unloading action of the main valve structure 311.

[0076] Optionally, in combination with Figure 3 As shown, the hydraulic protection system 100 of the press further comprises a plurality of one-way valves 7, each of the one-way valves 7 is arranged on a corresponding one of the oil inlet pipes 4, and the one-way valve 7 is used to limit the reverse flow of the hydraulic oil of the hydraulic protection oil cylinder 2 to the oil outlet.

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

[0078] In this optional embodiment, the oil pump of the hydraulic station 1 can pump hydraulic oil from the hydraulic oil tank, and deliver the hydraulic oil along the oil inlet pipe 4 through the one-way valve 7 to the hydraulic protection oil cylinder 2, and the hydraulic oil in the working cavity of the hydraulic protection oil cylinder 2 cannot flow reversely to the hydraulic station 1 through the one-way valve 7, so the one-way valve 7 can effectively limit the reverse flow of the hydraulic oil of the hydraulic protection oil cylinder 2 to the oil outlet.

[0079] Optionally, in combination with Figure 3As shown, the pressure detection structure 6 comprises a plurality of pressure detection devices 61, which are arranged on the oil inlet pipe 4 at intervals, and are configured to different levels of overload pressure values.

[0080] Specifically, a plurality of pressure detection devices 61 can be arranged on each oil inlet pipe 4 corresponding to the hydraulic protection oil cylinder 2, and each pressure detection structure 6 can comprise three pressure detection devices 61 (see Figure 3 As shown, the pressure detection structure 6 comprises a plurality of pressure detection devices 61, which are arranged on the oil inlet pipe 4 at intervals, and are configured to different levels of overload pressure values.

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

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

[0083] The unloading valve group 3 can protect the safety of the transmission mechanism and the die of the press, and the overload pressure values of the plurality of pressure detection devices 61 are different, so that the unloading function can be realized according to the actual working requirement for different levels of punching force, and the range of workpiece types punched on the die by the press is correspondingly expanded.

[0084] Optionally, the hydraulic protection system 100 of the press further comprises a plurality of pressure gauges 8, each of which is in communication with a corresponding hydraulic protection oil cylinder 2 and is used to display the pressure value of the hydraulic protection oil cylinder 2.

[0085] Specifically, one pressure gauge 8 can be configured for each hydraulic protection oil cylinder 2, which can be directly in communication with the working chamber of the hydraulic protection oil cylinder 2, or arranged on the pipeline between the hydraulic protection oil cylinder 2 and the unloading valve group 3.

[0086] In the optional embodiment, each pressure gauge 8 can be used to monitor the pressure value (e.g. oil pressure) of the corresponding hydraulic protection cylinder 2 in real time, and display the corresponding pressure reading, so that the staff can know the pressure value of each hydraulic protection cylinder 2 in real time.

[0087] Optionally, the hydraulic protection system 100 of the press further comprises a control device, each pressure detection structure 6 is arranged at a position close to the hydraulic protection cylinder 2 of the corresponding oil inlet pipe 4, and each pressure detection structure 6 is electrically connected to the control device, the control device is electrically connected to the plurality of electromagnetic valves 32, and the control device is used to control the plurality of electromagnetic valves 32 to open simultaneously according to at least one overload signal.

[0088] Specifically, the control device can be a control panel, a controller or the like, and each pressure detection structure 6 is electrically connected to a signal end of the control device, and a control end of the control device is electrically connected to the plurality of electromagnetic valves 32.

[0089] In the optional embodiment, the pressure of the hydraulic oil close to the hydraulic protection cylinder 2 in the oil inlet pipe 4 is closer to the pressure value of the hydraulic oil in the working cavity of the hydraulic protection cylinder 2, so each pressure detection structure 6 is arranged at a position close to the hydraulic protection cylinder 2 of the corresponding oil inlet pipe 4, so as to ensure the detection accuracy of the pressure detection structure 6 to the pressure signal (or overload signal) of the hydraulic protection cylinder 2.

[0090] Since each pressure detection structure 6 is electrically connected to the control device, and the control device is electrically connected to the plurality of electromagnetic valves 32, when at least one of the plurality of hydraulic protection cylinders 2 generates an overload signal, the corresponding pressure detection structure 6 can transmit the overload signal to the control device, and the control device controls the plurality of electromagnetic valves 32 of the unloading valve group 3 to open simultaneously to unload, so as to ensure 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 in the figure, the hydraulic oil in the hydraulic station 1 can be delivered to the working cavity 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 cavity 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 electromagnetic valve 32 are all in the off state.

[0092] In combination with Figure 8As shown, when the pressure of any one of the hydraulic protection oil cylinders 2 reaches the set overload pressure, the pressure detection structure 6 detects the overload signal, and the corresponding overloading protection valve 31 of the overload signal opens the pilot valve core 3122 under the action of the hydraulic oil, so that the hydraulic oil of the hydraulic protection oil cylinder 2 flows in turn 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 discharge oil chamber 3127, the first return oil chamber 3116 of the main valve structure 311, the oil discharge port 3118, the return oil pipe 5, and 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 electromagnetic valve 32 are not opened at this time, they are all in the off state.

[0093] In combination Figure 9 As shown, the pressure detection device 61 can send the detected overload signal to the electromagnetic valve 32 through the control device, and the corresponding electromagnetic valve 32 of the four hydraulic protection oil cylinders 2 is opened, and the pilot valve core 3122 of the corresponding overloading protection valve 31 of the overload signal is opened under the action of the hydraulic oil, so that the hydraulic oil of the hydraulic protection oil cylinder 2 flows in turn through the working oil chamber 3115, the main valve damping hole 3117, the pilot pressure oil chamber 3126, the electromagnetic 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 discharge port 3118, the return oil pipe 5, and the hydraulic oil tank of the hydraulic station 1. 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 large.

[0094] In combination Figure 10 As shown, the pressure difference before and after the main valve damping hole 3117 becomes large, and the main valve core 3112 is fully opened under the action of the pressure difference, so that the high-pressure hydraulic oil of the working oil chamber 3115 of the main valve structure 311 returns quickly to the hydraulic station 1 through the first return oil chamber 3116, the oil discharge port 3118, and the return oil pipe 5, so that the system pressure is unloaded, and the protection function of the press equipment is completed.

[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 electromagnetic valve 32 is manually reset.

[0096] Finally, after the overload working condition is checked, the hydraulic protection oil cylinder and the working oil chamber are filled with pre-pressing hydraulic oil by the hydraulic station, the overloading protection valve completes the reset process, and the press can work normally.

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

[0098] The utility model discloses an embodiment provides a kind of press, including the hydraulic protection system 100 of press as described in above embodiment.

[0099] In combination Figure 11 As shown in the drawing, the press in the embodiment further includes an upper beam 200, a transmission mechanism 700, a column 400, a sliding block 300, a workbench 500 and a base 600, wherein the base 600 can be installed on a support surface such as the ground, the workbench 500 is installed on the base 600, and a die can be installed on the workbench 500. The die is used to place a 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 end of the plurality of columns 400 to support the upper beam 200 through the columns 400. The fixed end of the plurality of hydraulic protection oil cylinders 2 can be installed on the sliding block 300. The piston rod of the plurality of hydraulic protection oil cylinders 2 is upward and connected to the transmission mechanism 700 of the press. The hydraulic station 1 can be installed on the sliding block 300. The piston rod of the hydraulic protection oil cylinder 2 drives the sliding block 300 to move up and down through the transmission mechanism 700 of the press to perform stamping work on the workpiece on the workbench 500. The transmission mechanism 700 can be a transmission device with a reduction function composed of a gear box and a connecting rod. It is prior art and is not limited here.

[0100] The beneficial effects of the press of the 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 repeated here.

[0101] Although the utility model discloses as above, the protection scope of the utility model is not limited to this. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model, and these changes and modifications will fall within the protection scope of the utility model.

Claims

1. A hydraulic protection system for a press, characterized in that, The hydraulic station (1) has an oil outlet and an oil return port, both ends of each oil inlet pipe (4) are communicated with the oil outlet and the corresponding hydraulic protection oil cylinder (2) respectively, and the unloading valve group (3) includes an overload protection valve (31) and a solenoid valve (32), the working oil cavity (3115) of the overload protection valve (31) is communicated with the corresponding hydraulic protection oil cylinder (2), and the first oil return cavity (3116) is communicated with the oil return port through the corresponding oil return pipe (5); The pressure detection structure (6) is used for detecting overload signals of the corresponding hydraulic protection oil cylinder (2), the pressure detection structure (6) is electrically connected with the solenoid valve (32), and a plurality of solenoid valves (32) are used for being opened at the same time according to at least one overload signal; the solenoid valve (32) includes a solenoid valve pressure oil cavity (321) and a second oil return cavity (322), the solenoid valve pressure oil cavity (321) is communicated with the working oil cavity (3115), and the second oil return cavity (322) is communicated with the oil return port through the oil return pipe (5).

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

3. The hydraulic protection system of a press according to claim 2, characterized in that, 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), the inside of the pilot valve body (3121) is provided with a third installation cavity (3125), 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); The pilot valve body (3121) has a pilot pressure oil cavity (3126) and a pilot unloading oil cavity (3127), the other end of the main valve damping hole (3117) communicates the pilot unloading oil cavity (3127) through the pilot pressure oil cavity (3126) and the third mounting cavity (3125) in turn, and the pilot unloading oil cavity (3127) communicates the first oil return cavity (3116).

4. The hydraulic protection system of a press according to claim 2, characterized in that, When the electromagnetic valve (32) is opened, The second oil return cavity (322) of the electromagnetic valve (32) communicates the oil return pipe (5) through the first oil return cavity (3116); or, the main valve body (3111) is provided with a communication flow channel (3119), and the second oil return cavity (322) of the electromagnetic valve (32) communicates the oil return pipe (5) through the communication flow channel (3119).

5. The hydraulic protection system of a press 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) becomes large, the main valve spring (3113) pushes the main valve core (3112) to move in the first mounting cavity, and the working oil cavity (3115) communicates the first oil return cavity (3116); The main valve body (3111) is provided with an unloading port (3118), one end of the unloading port (3118) communicates the first oil return cavity (3116), and the other end of the unloading port (3118) communicates the oil return port through the oil return pipe (5).

6. The hydraulic protection system for a press according to claim 1, characterized in that, The hydraulic protection system (100) further comprises a plurality of one-way valves (7), each of the one-way valves (7) is arranged on a corresponding one of the oil inlet pipes (4), and the one-way valves (7) are used to limit the hydraulic oil of the hydraulic protection oil cylinder (2) from flowing reversely to the oil outlet.

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

8. The hydraulic protection system for a press according to claim 1, characterized in that, The hydraulic protection system (100) further comprises a plurality of pressure gauges (8), each of the pressure gauges (8) communicates with a corresponding one of the hydraulic protection oil cylinders (2) and is used to display the pressure value of the corresponding one of the hydraulic protection oil cylinders (2).

9. The hydraulic protection system for a press according to claim 1, characterized in that, The hydraulic protection system (100) further comprises a control device, each of the pressure detection structures (6) is arranged at a position close to the hydraulic protection oil cylinder (2) of a corresponding one of the oil inlet pipes (4), each of the pressure detection structures (6) is electrically connected to the control device, the control device is electrically connected to the plurality of electromagnetic valves (32), and the control device is used to control the plurality of electromagnetic valves (32) to be opened simultaneously according to at least one of the overload signals.

10. A press machine characterized by, The hydraulic protection system (100) comprises the press machine according to any one of claims 1 to 9.

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