Back pressure device for mold with ejector rod, using method and mold with ejector rod

Abstract

The backpressure device comprises a backpressure assembly and a hydraulic assembly, the backpressure assembly comprises an upper working table, an oil accumulator, an oil cylinder, a base plate, a guide column, a piston and a force bearing plate, gaps exist between the two sides of the guide column and the upper working table, and the hydraulic assembly is arranged on the upper working table. The gap is communicated with the oil accumulator and the oil cavity, the lower portion of the guide column extends into the oil cavity and is connected with the piston, the piston is located in the oil cavity, and a force bearing plate is arranged below the piston. According to the technical scheme, an oil film can be formed in the gap, once the piston is subjected to unbalance loading, the thickness of the oil film changes, and pressure differences in opposite directions are formed on the two sides of the guide column, so that unbalance loading resisting torque is formed, unbalance loading of the piston is corrected, normal movement of the piston is guaranteed, and the unbalance loading resisting capacity of the backpressure device is improved. In addition, due to the fact that an oil film is formed in the gap between the guide column and the upper workbench, actual abrasion between the guide column and the upper workbench is avoided under the action of the oil film, the service life of the backpressure device is prolonged, and the backpressure device is prevented from being damaged.

Description

Technical Field

[0001] The present invention relates to the field of precision hydraulic technology, and in particular to a back pressure device for a mold with a push rod, a use method and the mold with a push rod. Background Art

[0002] The back pressure device inputs a certain amount of pressure oil into the back pressure cylinder through the hydraulic system during the working process to ensure that the cylinder maintains a certain pressure. As a result, the back pressure piston and the bearing plate will be subjected to a certain pressure, but under the restriction of the pad, they will remain in a fixed position, and the piston and the bearing plate will not be pushed out of the back pressure cylinder. When the back pressure piston and the bearing plate are subjected to a certain external force, they will retreat, and the excess hydraulic oil will be discharged back to the oil tank through the return pipe and the overflow valve. When the external force is small or disappears, the hydraulic system will continue to fill the back pressure cylinder with oil, and the cylinder pressure will push the back pressure piston and the bearing plate back to the fixed position. The back pressure device is generally used to provide a certain pressure and displacement space for the mold ejector.

[0003] like Figure 1 As shown, the existing back pressure device 100a provides hydraulic oil to the oil cylinder 3a arranged under the workbench 2a through the hydraulic system 1a, and under the restriction of the pad 6a, the piston 4a and the bearing plate 5a will not be pushed out of the oil cylinder 3a. However, when the piston 4a is subjected to an eccentric load, the piston 4a and the bearing plate 5a are prone to tilt, causing friction between the piston 4a and the oil cylinder 3a, reducing the life of the back pressure device 100a, and even causing damage to the back pressure device 100a. Summary of the invention

[0004] To this end, it is necessary to provide a back pressure device for a mold with a push rod, a method of use and a mold with a push rod, so as to solve the technical problem that the existing back pressure piston and load-bearing plate are prone to tilt when subjected to an offset load, causing friction between the piston and the cylinder, reducing the life of the back pressure device, and even causing damage to the back pressure device.

[0005] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a back pressure device for a mold with a push rod, comprising a back pressure assembly and a hydraulic assembly, the back pressure assembly comprising an upper workbench, an oil accumulator, a cylinder, a pad, a guide column, a piston and a bearing plate, a first through hole is provided on the upper workbench, an oil accumulator is arranged above the upper workbench, an oil cylinder is arranged below the upper workbench, the cylinder has an oil chamber, a pad is arranged below the cylinder, a second through hole is provided on the pad, the guide column is arranged in the first through hole, there is a gap between the guide column and the upper workbench, the gap is respectively connected with the oil accumulator and the oil chamber, the lower part of the guide column extends into the oil chamber and is connected with the piston, the piston is located in the oil chamber, a bearing plate is arranged below the piston, and the bearing plate slides in the pad through the second through hole; the hydraulic assembly comprises an oil tank, an oil pump and an oil inlet pipeline, the oil pump is installed on the oil inlet pipeline, the oil tank is connected with the oil chamber through the oil inlet pipeline, and the oil tank is used to supply oil to the oil chamber.

[0006] As an embodiment of the present invention, the back pressure assembly further includes a guide rail, which is disposed in the first through hole and sleeved outside the guide column with a gap between the guide rail and the guide column.

[0007] As an implementation mode of the present invention, the hydraulic assembly further includes an oil return pipeline, and the oil accumulator is connected to the oil tank through the oil return pipeline.

[0008] As an embodiment of the present invention, the hydraulic component also includes a motor, a throttle valve, a one-way valve, a first branch, a safety relief valve, a second branch and a pressure relief valve. The motor is connected to the oil pump, and the motor is used to provide power for the oil pump. The throttle valve and the one-way valve are installed on the oil inlet pipeline. The first branch is connected to the oil inlet pipeline, and the first branch is located between the oil pump and the throttle valve. The safety relief valve is installed on the first branch, and the second branch is connected to the oil inlet pipeline. The second branch is located between the one-way valve and the oil chamber, and the pressure relief valve is installed on the second branch.

[0009] As an embodiment of the present invention, the back pressure assembly also includes a hydraulic sensor, which is installed in the oil chamber. The hydraulic sensor is communicatively connected with the oil pump and is used to detect the oil pressure in the oil chamber to control the oil pump to work or stop working.

[0010] As an embodiment of the present invention, the gap is 0.01 mm-0.08 mm.

[0011] To achieve the above object, in a second aspect, the inventor provides a method for using a back pressure device for a mold with a push rod, comprising any one of the back pressure devices for a mold with a push rod provided by the inventor above, and further comprising the following steps:

[0012] S1: Start the oil pump, and the oil tank delivers the hydraulic oil to the oil chamber through the oil inlet pipeline. The hydraulic oil in the oil chamber will leak to the oil accumulator through the gap, thus forming an oil film in the gap;

[0013] S2: When the normal pressure on the bearing plate is greater than the cylinder pressure, the piston is pushed upward in the vertical direction, the oil pressure in the cylinder increases, and when the oil pressure increases to the specified pressure, the hydraulic oil in the cylinder flows back to the oil tank;

[0014] S3: When the normal pressure on the load-bearing plate is less than the cylinder pressure, the oil pump is started again, and the oil tank delivers the hydraulic oil to the oil chamber again through the oil inlet pipeline, pushing the piston to move downward in the vertical direction to the initial position.

[0015] As an embodiment of the present invention, it is important to explain in step S2 that: when the load-bearing plate is off-loaded, the piston is also off-loaded, and the hydraulic oil in the gap on the side affected by the off-load force leaks to the oil reservoir, the thickness of the oil film changes and forms a pressure difference in opposite directions on both sides of the guide column, thereby forming an anti-off-load torque to return the guide column to its original position.

[0016] Different from the prior art, the above technical solution is provided with a guide column, a gap and an oil accumulator for storing the hydraulic oil flowing through the gap, thereby, an oil film can be formed in the gap. Once the piston is overloaded, the thickness of the oil film changes and a pressure difference in opposite directions will be formed on both sides of the guide column, thereby forming an anti-overload torque, correcting the overload of the piston, ensuring the normal movement of the piston, and improving the anti-overload ability of the back pressure device. No additional hydraulic device is needed in the whole process, and the oil film is established in the gap only by relying on the oil pressure of the cylinder itself. The structure is simple and easy to operate. In addition, since the oil film is formed in the gap between the guide column and the upper workbench, no actual wear will occur between the two under the action of the oil film, which will extend the service life of the back pressure device and avoid damage to the back pressure device.

[0017] To achieve the above-mentioned purpose, in a third aspect, the inventor provides a mold with a push rod, comprising a back pressure device, a punch device and a die device for the mold with a push rod as any one of the above-mentioned ones provided by the inventor, a punch device is connected below the back pressure device for the mold with a push rod, the punch device comprises an upper die seat, an upper pad, a punch, a pressure plate and a pressure ejector, the upper die seat is arranged below the pad, an upper pad is arranged below the upper die seat, a punch is arranged below the upper pad, the pressure plate is sleeved outside the bottom of the punch and is slidably connected to the punch, one end of the pressure ejector is connected to the load-bearing plate, and the other end of the pressure ejector passes through the upper die seat and the upper pad in sequence and then is connected to the pressure plate; the die device is located directly below the punch device, the die device comprises a lower workbench, a lower die seat and a die, a lower die seat is arranged on the lower workbench, a die seat is arranged on the lower die seat, the die has a cavity, and the top of the die is used for placing the blank to be processed.

[0018] As an embodiment of the present invention, the following steps are also included:

[0019] S1: Place the blank to be processed on top of the die, control the upper worktable to move downward in the vertical direction, and the punch and the press plate press the blank to be processed;

[0020] S2: Control the upper worktable to continue to move downward in the vertical direction, the punch processes the blank to be processed until the material frame is separated from the part, and the pressure plate moves the bearing plate and the piston upward in the vertical direction through the pressure ejector rod;

[0021] S3: Control the return stroke of the upper worktable, and the punch and the press plate drive the material frame to move upward in the vertical direction to the initial position;

[0022] S4: As the pressing force of the pressing plate disappears, the cylinder pressure decreases, and the oil tank delivers the hydraulic oil to the oil chamber again through the oil inlet pipeline, pushing the piston, the load-bearing plate, the pressing push rod and the pressing plate to move downward in the vertical direction to the initial position, separating the material frame from the punch, and the part naturally falls into the lower die seat, completing the entire processing process.

[0023] Different from the prior art, the above technical solution is provided with a mold with a push rod, under which the blank to be processed is processed. Since the back pressure device has good anti-eccentric load capability, the mold with a push rod is effectively prevented from being subjected to eccentric load during processing, ensuring the normal progress of the processing process.

[0024] The above-mentioned records related to the invention content are only an overview of the technical solution of the present application. In order to enable ordinary technicians in the field to more clearly understand the technical solution of the present application, and then implement it according to the text of the specification and the contents recorded in the drawings, and to make the above-mentioned purpose and other purposes, features and advantages of the present application easier to understand, the following is an explanation in combination with the specific implementation mode and drawings of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings are only used to illustrate the principles, implementation methods, applications, characteristics and effects of the specific embodiments of the present application and other related contents, and shall not be considered as limitations of the present application.

[0026] In the drawings of the specification:

[0027] Figure 1 is a schematic diagram of a back pressure device in the background technology;

[0028] Figure 2 This is a schematic diagram of placing and pressing a blank to be processed into a mold with a push rod according to an embodiment of the present application;

[0029] Figure 3 This is a schematic diagram of a punch in a mold with a push rod according to an embodiment of the present application acting on a blank to be processed;

[0030] Figure 4 This is a schematic diagram of an upper workbench after returning in a mold with a push rod according to an embodiment of the present application;

[0031] Figure 5 This is a schematic diagram of the separation of the material frame and the punch in a mold with a push rod according to an embodiment of the present application;

[0032] Figure 6 A schematic diagram of a back pressure device according to an embodiment of the present application;

[0033] Figure 7 for Figure 6 A magnified view of middle;

[0034] Figure 8 A schematic diagram of a back pressure assembly according to an embodiment of the present application.

[0035] The reference numerals in the above drawings are described as follows:

[0036] 100a-back pressure device; 1a-hydraulic system; 2a-workbench; 3a-oil cylinder; 4a-piston; 5a-load bearing plate; 6a-shield plate; 7a-hydraulic oil; 100-mold with ejector rod; 1-back pressure device; 11-back pressure assembly; 111-upper workbench; 112-oil accumulator; 113-oil cylinder; 114-shield plate; 115-guide column; 116-piston; 117-load bearing plate; 118-guide rail; 1191-gap; 1192-hydraulic sensor; 12-hydraulic assembly; 121-oil tank; 1211-hydraulic oil; 122-oil pump; 123-oil inlet pipeline; 124-oil return pipeline; 125-motor; 126-throttle valve; 127-check valve; 128-first branch; 1281-safety relief valve; 129-second branch; 1291-pressure relief valve; 2-punch device; 21-upper die seat; 22-upper pad; 23-punch; 24-pressing plate; 25-pressing ejector rod; 3-die device; 31-lower workbench; 32-lower die seat; 321-accommodating chamber; 33-die; 331-cavity; 4-blank to be processed; 41-material frame; 42-parts; Y-vertical direction. DETAILED DESCRIPTION

[0037] In order to explain in detail the possible application scenarios, technical principles, specific schemes that can be implemented, and the purposes and effects that can be achieved, the following is a detailed description of the specific embodiments listed in conjunction with the accompanying drawings. The embodiments described herein are only used to more clearly illustrate the technical solutions of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0038] Reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or association with other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way to form a corresponding implementable technical solution.

[0039] Unless otherwise defined, the technical terms used in this document have the same meanings as those generally understood by those skilled in the art to which this application belongs; the use of relevant terms in this document is only for describing specific embodiments and is not intended to limit this application.

[0040] In the description of this application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that three relationships may exist, for example, A and / or B, which means: A exists, B exists, and A and B exist at the same time. In addition, the character " / " in this article generally indicates that the objects before and after are in an "or" logical relationship.

[0041] In the present application, terms such as “first” and “second” are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship of quantity, priority or sequence between these entities or operations.

[0042] Without further limitations, in this application, the words "include", "comprises", "has" or other similar expressions used in the sentences are intended to cover non-exclusive inclusion. These expressions do not exclude the presence of additional elements in the process, method or product including the elements, so that the process, method or product including a series of elements may include not only those limited elements, but also other elements not explicitly listed, or also include elements inherent to such process, method or product.

[0043] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceed" and the like are understood to exclude the number itself; expressions such as "above", "below", "within" and the like are understood to include the number itself. In addition, in the description of the embodiments of this application, "multiple" means more than two (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups", "multiple times", etc., unless otherwise clearly and specifically limited.

[0044] In the description of the embodiments of the present application, space-related expressions used, such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "vertical", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or position relationship based on the orientation or position relationship shown in the specific embodiments or drawings, and are only for the convenience of describing the specific embodiments of the present application or facilitating the reader's understanding, and do not indicate or imply that the referred device or component must have a specific position, a specific orientation, or be constructed or operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0045] Unless otherwise expressly specified or limited, in the description of the embodiments of the present application, the terms such as "install", "connect", "connect", "fix", "set", etc. used should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integrated setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For technicians in the technical field to which the present application belongs, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] According to some embodiments of the present application, please refer to Figures 2 to 5 The present embodiment relates to a mold with a push rod 100, comprising a back pressure device 1, a punch device 2 and a die device 3 for the mold with a push rod 100, the punch device 2 is connected below the back pressure device 1 for the mold with a push rod 100, the punch device 2 comprises an upper die seat 21, an upper pad 22, a punch 23, a press plate 24 and a press ejector 25, the upper die seat 21 is arranged below the pad 114, the upper pad 22 is arranged below the upper die seat 21, the punch 23 is arranged below the upper pad 22, the press plate 24 is sleeved on the punch The bottom of the punch 23 is outside the bottom of the punch 23 and is slidably connected to the punch 23. One end of the push rod 25 is connected to the load-bearing plate 117, and the other end of the push rod 25 passes through the upper die seat 21 and the upper pad 22 in sequence and is connected to the pressure plate 24; the die device 3 is located directly below the punch device 2, and the die device 3 includes a lower workbench 31, a lower die seat 32 and a die 33. The lower workbench 31 is provided with a lower die seat 32, and the lower die seat 32 is provided with a die 33. The die 33 has a cavity 331, and the top of the die 33 is used for placing the blank 4 to be processed.

[0047] The mold with ejector pin 100 may be a stamping mold, a punching mold or other existing molds with ejector pins.

[0048] The pressing plate 24 is connected to the bearing plate 117 of the back pressure device 1 through the pressing rod 25, and because the pressing plate 24 is slidably connected relative to the punch 23, when the pressing plate 24 is subjected to pressure and moves upward along the vertical direction Y, it will drive the bearing plate 117 to move upward along the vertical direction Y in the oil cylinder 113, and the oil pressure of the oil cylinder 113 will increase. Preferably, two pressing rods 25 are provided, and one pressing rod 25 is provided on each side of the punch 23.

[0049] The concave mold 33 corresponds to the convex mold 23, and the internal cavity 331 is for the processed part 42 and the convex mold 23 to enter. Optionally, the lower mold base 32 has a receiving cavity 321, which is located below the cavity 331 and communicates with the cavity 331. Preferably, the diameter of the receiving cavity 321 is set larger than the diameter of the cavity 331, and the receiving cavity 321 can be dropped into the part 42, which is convenient for subsequent retrieval.

[0050] According to some embodiments of the present application, optionally, Figures 2 to 5 As shown, the following steps are also included:

[0051] S1: Figure 2 As shown, the blank 4 to be processed is placed above the die 33, and the upper workbench 111 is controlled to move downward along the vertical direction Y, and the punch 23 and the pressing plate 24 press the blank 4 to be processed;

[0052] S2: Figure 3 As shown, the upper workbench 111 is controlled to continue to move downward along the vertical direction Y, the punch 23 processes the blank 4 to be processed until the material frame 41 is separated from the part 42, and the pressing plate 24 moves the bearing plate 117 and the piston 116 upward along the vertical direction Y through the pressing ejector rod 25;

[0053] S3: Figure 4 As shown, the upper workbench 111 is controlled to return, and the punch 23 and the pressing plate 24 drive the material frame 41 to move upward along the vertical direction Y to the initial position;

[0054] S4: Figure 5 As shown, since the pressing force of the pressing plate 24 disappears, the pressure in the oil cylinder 113 decreases, and the oil tank 121 delivers the hydraulic oil 1211 to the oil chamber again through the oil inlet line 123, pushing the piston 116, the load-bearing plate 117, the pressing push rod 25 and the pressing plate 24 to move downward along the vertical direction Y to the initial position, separating the material frame 41 from the punch 23, and the part 42 naturally falls into the lower die base 32, completing the entire processing process.

[0055] In actual use, an external mechanical device will control the upper workbench 111 to process downward or return upward along the vertical direction Y. Among them, it is important to explain in S2 that: during the process of the punch 23 processing the blank 4 to be processed until the material frame 41 and the part 42 are separated, the punch 23 acts on the blank 4 to process the part 42 into the die 33, and the press plate 24, under the action of the material frame 41, moves the bearing plate 117 and the piston 116 upward along the vertical direction Y through the press rod 25.

[0056] The above technical solution is provided with a mold with a push rod 100, under the action of the mold with a push rod 100, the blank 4 to be processed is processed. Since the back pressure device 1 has good anti-eccentric load capability, the mold with a push rod 100 is effectively prevented from being subjected to eccentric load during processing, ensuring the normal progress of the processing process.

[0057] According to some embodiments of the present application, please refer to Figures 6 to 8 The present embodiment also relates to a back pressure device 1 for a mold with a push rod 100, comprising a back pressure assembly 11 and a hydraulic assembly 12. The back pressure assembly 11 comprises an upper workbench 111, an oil accumulator 112, an oil cylinder 113, a pad 114, a guide column 115, a piston 116 and a bearing plate 117. A first through hole is provided on the upper workbench 111, an oil accumulator 112 is provided above the upper workbench 111, an oil cylinder 113 is provided below the upper workbench 111, the oil cylinder 113 has an oil cavity, a pad 114 is provided below the oil cylinder 113, a second through hole is provided on the pad 114, and the guide column 115 is provided at the first through hole. In the through hole, there is a gap 1191 between the guide column 115 and the upper workbench 111, and the gap 1191 is respectively connected to the oil accumulator 112 and the oil chamber. The lower part of the guide column 115 extends into the oil chamber and is connected to the piston 116. The piston 116 is located in the oil chamber. A load-bearing plate 117 is arranged below the piston 116, and the load-bearing plate 117 slides in the pad 114 through the second through hole; the hydraulic assembly 12 includes an oil tank 121, an oil pump 122 and an oil inlet pipeline 123, the oil pump 122 is installed on the oil inlet pipeline 123, the oil tank 121 is connected to the oil chamber through the oil inlet pipeline 123, and the oil tank 121 is used to supply oil to the oil chamber.

[0058] The oil accumulator 112 is used to store the hydraulic oil 1211 leaked through the gap 1191, and the hydraulic oil 1211 leaked during the formation of the oil film in the gap 1191 has little effect on the pressure of the cylinder 113. Among them, the piston 116 is connected to the load-bearing plate 117, and the load-bearing plate 117 slides in the pad 114 through the second through hole. The diameter of the second through hole is smaller than the diameter of the piston 116. Therefore, it can be ensured that the piston 116 and the load-bearing plate 117 will not be pushed out of the cylinder 113 under the restriction of the pad 114. Preferably, the cross-section of the oil chamber is set to be a convex shape, which is conducive to the processing of the cylinder 113 and the assembly of the guide column 115. Among them, the piston 116 and the cylinder 113 are sealed and connected by a sealing ring to ensure the sealing between the two.

[0059] The above technical solution is provided with a guide column 115, a gap 1191 and an oil accumulator 112 for storing hydraulic oil 1211 flowing through the gap 1191, thereby, an oil film can be formed in the gap 1191. Once the piston 116 is overloaded, the thickness of the oil film changes and a pressure difference in opposite directions is formed on both sides of the guide column 115, thereby forming an anti-overload torque, correcting the overload of the piston 116, ensuring the normal movement of the piston 116, and improving the anti-overload ability of the back pressure device 1. No additional hydraulic device is needed in the whole process, and the oil film is established in the gap 1191 only by relying on the oil pressure of the oil cylinder 113. The structure is simple and easy to operate. In addition, since an oil film is formed in the gap 1191 between the guide column 115 and the upper workbench 111, no actual wear will occur between the two under the action of the oil film, which will extend the service life of the back pressure device 1 and avoid damage to the back pressure device 1.

[0060] According to some embodiments of the present application, optionally, Figure 6 and Figure 8 As shown, the back pressure assembly 11 further includes a guide rail 118 . The guide rail 118 is disposed in the first through hole. The guide rail 118 is sleeved outside the guide column 115 , and a gap 1191 exists between the guide rail 118 and the guide column 115 .

[0061] The guide rail 118 can be provided to further prevent the guide column 115 from directly contacting the upper workbench 111 . In addition, the guide column 115 slides relative to the guide rail 118 , so that the guide column 115 can move along the vertical direction Y.

[0062] According to some embodiments of the present application, optionally, Figure 6 As shown, the hydraulic assembly 12 further includes an oil return pipeline 124 , and the oil accumulator 112 is connected to the oil tank 121 via the oil return pipeline 124 .

[0063] When the hydraulic oil 1211 in the oil accumulator 112 is stored in a certain amount, it can flow back to the oil tank 121 through the oil return line 124. By setting the oil return line 124, the hydraulic oil 1211 stored in the oil accumulator 112 can be recovered into the oil tank 121, avoiding the loss of the hydraulic oil 1211.

[0064] According to some embodiments of the present application, optionally, Figure 6As shown, the hydraulic component 12 also includes a motor 125, a throttle valve 126, a one-way valve 127, a first branch 128, a safety relief valve 1281, a second branch 129 and a pressure relief valve 1291. The motor 125 is connected to the oil pump 122, and the motor 125 is used to provide power for the oil pump 122. The throttle valve 126 and the one-way valve 127 are installed on the oil inlet pipeline 123. The first branch 128 is connected to the oil inlet pipeline 123. The first branch 128 is located between the oil pump 122 and the throttle valve 126. The safety relief valve 1281 is installed on the first branch 128. The second branch 129 is connected to the oil inlet pipeline 123. The second branch 129 is located between the one-way valve 127 and the oil chamber. The pressure relief valve 1291 is installed on the second branch 129.

[0065] When the motor 125 starts the oil pump 122, the oil pump 122 delivers the hydraulic oil 1211 in the oil tank 121 to the oil inlet line 123. The safety relief valve 1281 installed on the first branch 128 is used to ensure that the pressure of the hydraulic component 12 does not exceed the set safety pressure, thereby ensuring the safety of the hydraulic component 12. The hydraulic oil 1211 in the oil inlet line 123 is then delivered to the oil cylinder 113 through the throttle valve 126 and the one-way valve 127 to ensure that the oil cylinder 113 maintains the set oil pressure, and the oil pressure is then set through the pressure relief valve 1291. When the pressure exerted by the mold on the bearing plate 117 is greater than the back pressure of the piston 116, the piston 116 will be pushed back (moved upward in the vertical direction Y), and the oil pressure in the oil cylinder 113 will increase. When the oil pressure in the oil cylinder 113 is greater than the pressure set by the pressure relief valve 1291, the excess hydraulic oil 1211 will flow back to the oil tank 121 through the oil inlet pipeline 123, the second branch 129 and the pressure relief valve 1291. Once the pressure exerted by the bearing plate 117 is less than the pressure in the oil cylinder 113, the oil pump 122 will deliver the hydraulic oil 1211 to the oil cylinder 113, pushing the piston 116 downward and ensuring that the hydraulic oil 1211 in the oil cylinder 113 maintains a certain pressure.

[0066] According to some embodiments of the present application, optionally, Figure 6 As shown, the back pressure assembly 11 also includes a hydraulic sensor 1192, which is installed in the oil chamber. The hydraulic sensor 1192 is in communication with the oil pump 122, and the hydraulic sensor 1192 is used to detect the oil pressure in the oil chamber to control the oil pump 122 to work or stop working.

[0067] The hydraulic sensor 1192 is installed above the oil chamber and does not affect the normal movement of the piston 116 in the vertical direction Y. The hydraulic sensor 1192 can detect the oil pressure in the oil chamber in real time, thereby further ensuring the oil pressure of the oil cylinder 113. When the hydraulic sensor 1192 detects that the oil pressure is greater than the pressure borne by the bearing plate 117, the oil pump 122 is controlled to work until the hydraulic oil 1211 in the oil cylinder 113 is maintained at a specified pressure, and then the oil pump 122 is controlled to stop working.

[0068] According to some embodiments of the present application, optionally, Figure 7 and Figure 8 As shown, the gap 1191 is 0.01 mm-0.08 mm.

[0069] The gap 1191 is a tiny gap, specifically, the gap 1191 is set to 0.01mm-0.08mm. In actual use, the length Ldz and diameter Ddz of the guide column 115 and the length Ldg of the guide rail 118 are determined according to the actual anti-eccentric load capacity requirements; the gap 1191 is determined based on the actual structural dimensions and the use pressure of the back pressure device 1 to form a stable and reliable oil film. Specifically, as Figure 8 As shown, the maximum movable distance of the piston 116 is set to Lp, the diameter of the piston 116 is Dp, the length of the guide column 115 is Ldz=(0.4-0.6)Dp, the diameter Ddz=(0.25-0.35)Dp, and the length of the guide rail 118 is Ldg=Ldz-1.1Lp.

[0070] According to some embodiments of the present application, please refer to Figure 6 The present embodiment also relates to a method for using a back pressure device 1 for a mold with a push rod 100, including the back pressure device 1 for a mold with a push rod 100, and further including the following steps:

[0071] S1: Start the oil pump 122, and the oil tank 121 delivers the hydraulic oil 1211 to the oil chamber through the oil inlet pipe 123. The hydraulic oil 1211 in the oil chamber leaks to the oil accumulator 112 through the gap 1191, thereby forming an oil film in the gap 1191;

[0072] S2: When the normal pressure on the bearing plate 117 is greater than the pressure in the oil cylinder 113, the piston 116 is pushed upward along the vertical direction Y, the oil pressure in the oil cylinder 113 increases, and when the oil pressure increases to a specified pressure, the hydraulic oil 1211 in the oil cylinder 113 flows back to the oil tank 121;

[0073] S3: When the normal pressure on the load-bearing plate 117 is less than the pressure of the oil cylinder 113, the oil pump 122 is started again, and the oil tank 121 delivers the hydraulic oil 1211 to the oil chamber again through the oil inlet pipe 123, pushing the piston 116 to move downward along the vertical direction Y to the initial position.

[0074] According to some embodiments of the present application, optionally, what needs to be emphasized in step S2 is: when the load-bearing plate 117 is off-loaded, the piston 116 is also off-loaded, and the hydraulic oil 1211 in the gap 1191 on the side affected by the off-load force leaks to the oil reservoir 112, and the thickness of the oil film changes and forms a pressure difference in opposite directions on both sides of the guide column 115, thereby forming an anti-off-load torque to return the guide column 115 to its original position.

[0075] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included in the patent protection scope of the present invention.

Claims

1. A back pressure device for a mold with a push rod, characterized in that: include: A back pressure assembly, the back pressure assembly comprising an upper workbench, an oil accumulator, an oil cylinder, a pad, a guide column, a piston and a bearing plate, the upper workbench being provided with a first through hole, the oil accumulator being arranged above the upper workbench, the oil cylinder being arranged below the upper workbench, the oil cylinder having an oil chamber, the pad being arranged below the oil cylinder, the pad being provided with a second through hole, the guide column being arranged in the first through hole, a gap being provided between the guide column and the upper workbench, the gap being respectively connected with the oil accumulator and the oil chamber, the lower part of the guide column extending into the oil chamber and connected with the piston, the piston being located in the oil chamber, the bearing plate being arranged below the piston, the bearing plate sliding in the pad through the second through hole; A hydraulic assembly, the hydraulic assembly comprising an oil tank, an oil pump and an oil inlet pipeline, the oil pump being installed on the oil inlet pipeline, the oil tank being connected to the oil chamber through the oil inlet pipeline, and the oil tank being used to supply oil to the oil chamber.

2. The back pressure device for a mold with a push rod according to claim 1, characterized in that: The back pressure assembly further includes a guide rail, which is disposed in the first through hole and sleeved outside the guide post, with the gap existing between the guide rail and the guide post.

3. The back pressure device for a mold with a push rod according to claim 1, characterized in that: The hydraulic assembly further comprises an oil return pipeline, and the oil accumulator is connected to the oil tank via the oil return pipeline.

4. The back pressure device for a mold with a push rod according to claim 1, characterized in that: The hydraulic assembly also includes a motor, a throttle valve, a one-way valve, a first branch, a safety relief valve, a second branch and a pressure relief valve. The motor is connected to the oil pump, and the motor is used to provide power for the oil pump. The throttle valve and the one-way valve are installed on the oil inlet pipeline. The first branch is connected to the oil inlet pipeline. The first branch is located between the oil pump and the throttle valve. The safety relief valve is installed on the first branch. The second branch is connected to the oil inlet pipeline. The second branch is located between the one-way valve and the oil chamber. The pressure relief valve is installed on the second branch.

5. The back pressure device for a mold with a push rod according to claim 1, characterized in that: The back pressure assembly also includes a hydraulic sensor, which is installed in the oil chamber. The hydraulic sensor is in communication with the oil pump and is used to detect the oil pressure in the oil chamber to control the oil pump to start or stop working.

6. The back pressure device for a mold with a push rod according to claim 1, characterized in that: The gap is 0.01mm-0.08mm.

7. A method for using a back pressure device for a mold with a push rod, characterized in that: The back pressure device for a mold with a push rod according to any one of claims 1 to 6 further comprises the following steps: S1: starting the oil pump, the oil tank delivers the hydraulic oil to the oil chamber through the oil inlet pipeline, the hydraulic oil in the oil chamber leaks to the oil accumulator through the gap, thereby forming an oil film in the gap; S2: When the normal pressure on the bearing plate is greater than the pressure in the oil cylinder, the piston is pushed to move upward in the vertical direction, the oil pressure in the oil cylinder increases, and when the oil pressure increases to a specified pressure, the hydraulic oil in the oil cylinder flows back to the oil tank; S3: When the normal pressure on the bearing plate is less than the oil cylinder pressure, the oil pump is started again, and the oil tank delivers the hydraulic oil to the oil chamber again through the oil inlet pipeline, pushing the piston to move downward in the vertical direction to the initial position.

8. The method for using the back pressure device for a mold with a push rod according to claim 7, characterized in that: It is important to note in step S2 that when the load-bearing plate is unbalancedly loaded, the piston is also unbalancedly loaded, and the hydraulic oil in the gap on the side affected by the unbalanced load leaks into the oil reservoir. The thickness of the oil film changes and forms a pressure difference in opposite directions on both sides of the guide column, thereby forming an anti-unbalanced load torque to return the guide column to its original position.

9. A mold with a push rod, characterized in that: include: A back pressure device for a mold with a push rod as claimed in any one of claims 1 to 6; A punch device, wherein the punch device is connected to the lower part of the back pressure device for the mold with a push rod, and the punch device comprises an upper die seat, an upper pad, a punch, a pressure plate and a pressure ejector rod. The upper die seat is arranged below the pad, the upper pad is arranged below the upper die seat, the punch is arranged below the upper pad, the pressure plate is sleeved outside the bottom of the punch and is slidably connected to the punch, one end of the pressure ejector rod is connected to the bearing plate, and the other end of the pressure ejector rod sequentially penetrates the upper die seat and the upper pad and is connected to the pressure plate; A die device, wherein the die device is located directly below the punch device, and the die device comprises a lower workbench, a lower die base and a die. The lower workbench is provided with the lower die base, the die is provided on the lower die base, the die has a cavity, and the top of the die is used for placing the blank to be processed.

10. The mold with ejector pin according to claim 9, characterized in that: The following steps are also included: S1: placing the blank to be processed above the concave die, controlling the upper worktable to move downward in the vertical direction, and the convex die and the pressing plate press the blank to be processed; S2: Control the upper worktable to continue to move downward along the vertical direction, the punch processes the blank to be processed until the material frame is separated from the part, and the pressure plate moves the bearing plate and the piston upward along the vertical direction through the pressure ejector rod; S3: Control the return stroke of the upper workbench, and the punch and the press plate drive the material frame to move upward along the vertical direction to an initial position; S4: As the pressing force of the pressing plate disappears, the pressure in the oil cylinder decreases, and the oil tank delivers the hydraulic oil to the oil chamber again through the oil inlet pipeline, pushing the piston, the load-bearing plate, the press rod and the pressing plate to move downward in the vertical direction to the initial position, separating the material frame from the punch, and the part naturally falls into the lower die seat, completing the entire processing process.

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