Hydraulic pressurization method and hydraulic pressurization mechanism

Abstract

The invention discloses a hydraulic pressurizing method and a hydraulic pressurizing mechanism. The hydraulic pressurizing mechanism comprises a pressurizing plate, a lateral locking mechanism used for locking the position of the pressurizing plate, and a composite cylinder arranged in the pressurizing plate and used for pressurizing a hydraulic machine. The pressurizing method of the hydraulic pressurizing mechanism has three working modes of normal pressure forming, pressurizing forming and pressure changing forming. According to the hydraulic pressurizing mechanism, existing equipment is properly modified, the hydraulic pressurizing mechanism is directly installed on a hydraulic machine, the pressure of the hydraulic machine is increased under the condition that an original hydraulic system and a main machine frame structure of the hydraulic machine are not changed, and large metal parts can be formed on the hydraulic machine with small tonnage; meanwhile, the original functions of the hydraulic machine can be reserved.

Description

Technical Field

[0001] The invention relates to the field of hydraulic presses, in particular to a hydraulic pressurizing method and a hydraulic pressurizing mechanism. Background Art

[0002] At present, when using hydraulic presses for precision plastic forming of large metal parts, a large forming force is often required to meet the requirements of material deformation; at the same time, a large working stroke is required. In general, a large hydraulic press is used to solve the problem. However, large hydraulic presses have a large structure, high price, complex hydraulic system, and low working speed during high-pressure forming, which greatly increases the production cost. Especially when the types of products produced by enterprises increase and the size increases, the existing small-tonnage hydraulic presses cannot meet the production requirements, and the purchase of large-tonnage presses is too expensive to be realized, it becomes a problem for enterprises and technicians to consider to modify the existing equipment to increase the forming pressure and use a booster mechanism to increase the forming tonnage of the existing hydraulic press.

[0003] At present, there are mainly two methods to increase the forming tonnage of hydraulic presses: (1) Increasing the tonnage of the press by increasing the pressure of the hydraulic system, but this requires a better high-pressure oil pump. After the oil pressure of the hydraulic system and the oil cylinder is increased, the corresponding hydraulic components need to be updated, the sealing problem also needs to be solved, and the main frame also needs to be strengthened. The cost of the transformation is too high; (2) Adding hydraulic cylinders to the main machine to increase the tonnage of the equipment also requires increasing the flow of the hydraulic system and strengthening the main frame structure. (3) Using a hydraulic cylinder with a boosting function to boost the equipment, although the hydraulic system structure can be kept basically unchanged, it will greatly increase the height of the hydraulic cylinder and the main frame also needs to be strengthened. It is powerless for hydraulic presses with large strokes.

[0004] A Chinese patent with publication number CN113210555A discloses a hydraulic booster mechanism that can boost pressure on existing equipment. The hydraulic system structure remains unchanged and the main frame does not need to be strengthened. However, after adopting the hydraulic booster mechanism, no matter how much pressure is required when extruding the product, the forming must be completed by the hydraulic booster mechanism, and the original forming pressure of the hydraulic press cannot be retained. Although the forming tonnage of the hydraulic press is increased, the forming pressure range of the hydraulic press is narrow, the practicality is small, and the working efficiency is reduced. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a hydraulic boosting method and a hydraulic boosting mechanism. The present invention appropriately transforms the existing equipment and directly installs the hydraulic boosting mechanism on the hydraulic press. Without changing the hydraulic system and the main frame structure of the original hydraulic press, the pressure of the hydraulic press is increased, and large metal parts can be formed on a hydraulic press of smaller tonnage, while retaining the original functions of the hydraulic press.

[0006] In order to achieve the above object, the specific scheme adopted by the present invention is: A hydraulic booster mechanism is installed on a hydraulic press, the hydraulic booster mechanism includes a booster plate, a lateral locking mechanism for locking the position of the booster plate, and a composite cylinder arranged in the booster plate for boosting the hydraulic press, the composite cylinder includes an upper small-diameter pressure cylinder and a lower large-diameter booster cylinder, a pressure piston is installed in the pressure cylinder, the piston rod of the pressure piston is fixed on the movable crossbeam of the hydraulic press or mechanically connected to the piston rod of the main oil cylinder of the hydraulic press; a booster piston is installed in the booster cylinder, the piston rod at the lower end of the booster piston is mechanically connected to a connecting plate, and the connecting plate is used for installing Mould; the composite cylinder is divided into an upper chamber of a pressure cylinder, a composite chamber and a lower chamber of a pressure cylinder by a pressure piston and a boosting piston, and the upper chamber of the pressure cylinder and the lower chamber of the boosting cylinder are controlled by the hydraulic system of the hydraulic press; the composite chamber is connected to the hydraulic system of the hydraulic press through a one-way valve; the lateral locking mechanism includes a side pin assembly and a restraining vertical plate rigidly connected to the lower cross beam of the hydraulic press, and the side pin assembly and the restraining vertical plate have restraining structures on the opposite sides, and when the side pin assembly is moved so that the restraining structure is in a locked state, the boosting plate can be locked so that it does not produce an upward backward movement when subjected to the forming force.

[0007] Furthermore, the pressure piston and the boosting piston are guided by guide pillars.

[0008] Furthermore, the side pin assembly includes a side pressure cylinder arranged in the booster plate and symmetrically arranged on both sides of the composite cylinder, a side pressure plunger installed in the side pressure cylinder, a side pin fixedly connected to the side pressure plunger, and a spring for making the side pin return inward.

[0009] Furthermore, the restraining structure includes an array of pin holes arranged on the inner side of the restraining vertical plate, and a plurality of rows of pin blocks arranged at the outer ends of the side pins and having shapes and positions consistent with the pin holes.

[0010] Furthermore, the constraint structure includes a vertical plate serration arranged on the inner side surface of the constraint vertical plate, and a side pin serration arranged on the outer end of the side pin and matching the shape of the vertical plate pin serration. The side pin serration can be locked with the vertical plate serrations of different heights. When the side pressure cylinder is working, the side pressure plunger drives the side pin to move outward, so that the side pin serrations are locked with the vertical plate serrations, generating a locking force in the vertical direction, thereby locking the position of the boost plate.

[0011] Furthermore, guide plates for guiding and restraining the side pins are symmetrically connected to both sides of the boost plate.

[0012] A hydraulic boosting method, which is implemented by the above hydraulic boosting mechanism, has three working modes: Mode 1: Normal pressure forming action: oil enters the upper chamber of the pressure cylinder, oil is discharged from the lower chamber of the booster cylinder, the pressure piston and the booster piston are both at the lower starting point position, so that the pressure piston, the booster piston and the cylinder cover are in mechanical contact, and the cylinder cover is fixed on the booster plate and sealed with the middle and lower part of the booster piston; when the press moves downward, the lateral locking mechanism and the composite cylinder do not work, and the hydraulic press works in a non-boosting mode, that is, the hydraulic press works in the original pressure and forming mode; Method 2: Boosting and forming action: oil is introduced into the lower chamber of the boosting chamber, and oil is discharged from the upper chamber of the pressure cylinder, so that both the boosting piston and the pressure piston are at the upper starting position; when the hydraulic press moves downward to the force-increasing position, the position sensor sends a signal, the boosting plate stops moving, oil is introduced into the side pressure cylinder, and the side pin moves outward to lock the restraining structure, and the boosting plate is locked; the hydraulic press drives the pressure piston downward, and the pressure of the hydraulic oil in the composite cylinder is transmitted to make the boosting piston move downward to perform boosting and forming action. The boosting multiple of the hydraulic press is the ratio of the area of ​​the boosting piston to the area of ​​the pressure piston; Method three, pressure-changing forming action: first perform the normal pressure forming action of method one; when pressed down to a certain position, the position sensor sends a signal to change the action of the hydraulic booster mechanism, so that the booster piston and the pressure piston both return to the upper starting point, and the side pin moves outward to lock the constraint structure and lock the booster plate; the hydraulic press continues to pressurize and move downward to complete the booster forming action.

[0013] Features and beneficial effects of the present invention: (1) The hydraulic booster mechanism of the present invention can increase the pressure of the equipment and realize high-pressure forming. Specifically, the hydraulic booster mechanism is installed on an ordinary hydraulic press, and the booster plate with a composite cylinder with a booster function and a lateral locking mechanism is installed on the movable crossbeam of the hydraulic press through the piston rod of the pressure piston, and a restraining vertical plate is installed on the lower crossbeam of the press; the composite cylinder has a larger diameter booster cylinder and a smaller diameter pressure cylinder. According to Pascal's principle, when the composite cylinder is subjected to force, the pressure acting on the booster piston and the pressure piston is equal, and the ratio of the force generated on the booster piston and the force applied to the composite cylinder by the pressure piston is equal to the ratio of the areas of the two, that is, the boost ratio generated by the composite cylinder. The pressure piston is connected to the movable crossbeam of the hydraulic press, and the booster piston is connected to the mold through a connecting plate. The pressure of the pressure piston is transmitted to the booster piston through the liquid medium in the composite cylinder, so as to realize boost output and generate a larger working pressure.

[0014] (2) Adding a booster plate to the hydraulic press will reduce the working stroke of the equipment. When the stroke becomes smaller and affects the forming operation, the movable crossbeam can be removed and the piston rod at the upper end of the pressure piston can be connected to the piston rod of the hydraulic cylinder of the hydraulic press to increase the working stroke of the equipment.

[0015] (3) The hydraulic booster mechanism of the present invention mainly comprises a booster plate equipped with a lateral locking mechanism and a hydraulic booster composite cylinder, and a restraining vertical plate for restraining the booster plate. It has a simple structure and a very low manufacturing cost. It can also maintain the rapid downward and return speed of the original hydraulic press, and has high working efficiency, thus having high economic and social benefits.

[0016] (4) With the scheme of the present invention, the hydraulic press still has the original fast no-load downward and return movements; when the hydraulic booster mechanism is working, the movement speed of the hydraulic press (pressure piston) can be changed into the slow movement of the booster piston and the mold, and the speed ratio is the ratio of the area of ​​the pressure piston to the area of ​​the booster plunger. Therefore, it has the characteristics of "fast downward movement, slow pressure application, slow pressure relief, and fast return", stable movement, conducive to improving production efficiency and energy saving, and easy operation.

[0017] (5) In the scheme of the present invention, the hydraulic booster mechanism locks the position of the booster plate on the restraining vertical plate through the lateral locking mechanism. During the booster forming, the reaction force is borne by the booster plate and the restraining vertical plate, and the hydraulic press frame still maintains the original load. The hydraulic booster mechanism of the present invention only works when the workpiece is boosted and formed, and its stroke is very short, so the impact on the working stroke of the hydraulic press is also very small.

[0018] (6) The hydraulic booster mechanism of the present invention still uses the original hydraulic system, and only adds three hydraulic valves for controlling the action of the booster mechanism and the lateral locking mechanism, and for supplying and replenishing oil to the composite chamber. No power device is needed. High pressure is only generated in the composite chamber of the composite cylinder during high-pressure forming, and the pressure of the hydraulic system is not affected. The equipment operates reliably and has good practicality.

[0019] (7) The constraint structure in the lateral locking mechanism is a serrated locking structure provided between the outer end of the side pin and the constraint vertical plate. The two have the same shape and structure, with a longer sawtooth length, a smaller tooth size, and a larger number of teeth. Compared with ordinary round or rectangular pin blocks, ① after locking, it has greater compressive strength and shear strength, and the stress concentration phenomenon is weakened, so it has a high locking strength; ② the smaller sawtooth structure can also reduce the locking stroke of the side pin; ③ the tooth height (along the downward direction of the hydraulic press) is small, and the distance between the side pin sawtooth and the vertical plate sawtooth from a certain locking height to the next adjacent locking height is very small, which can increase the position accuracy of the hydraulic press when it descends into a high-pressure state, thereby reducing the idle stroke and further improving work efficiency; ④ the sawtooth surface structure close to the horizontal plane facilitates the locking of the side pin and the constraint vertical plate and reduces the idle stroke; ⑤ the reduced idle stroke can reduce the height of the compound cylinder and the booster plate.

[0020] (8) Limited by the structure of the booster plate and the composite cylinder, the diameter of the pressure cylinder and the booster cylinder is large and the height is small, so the pressure piston and the booster piston are prone to rotation and tilt. A guide column is set between the pressure piston and the booster piston to make them cooperate and constrain each other, and the guide length of the composite cylinder is doubled, which can avoid the rotation and tilt of the booster piston and improve the anti-eccentric load capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of the hydraulic booster mechanism in Example 1.

[0022] Figure 2 Schematic diagram of the constraint structure in Example 2.

[0023] Figure 3 Schematic diagram of the constraint structure in Example 3.

[0024] Graphic markings: 1. Booster plate, 2. Booster piston, 3. Spring, 4. Guide plate, 5. Constraint vertical plate, 6. Lower cross beam, 7. Pressure piston, 8. Guide column, 9. Check valve, 10. Side pressure plunger, 11. Side pin, 12. Cylinder head, 13. Connecting plate, 14. Upper die, 15. Lower die, 16. Pin hole, 17. Pin block.

[0025] The meaning of the letters in the figure: a, upper chamber of pressure cylinder, b, lower chamber of booster cylinder, c, compound chamber, d, side pressure cylinder, M, vertical plate serrations, N, side pin serrations, Q, frame. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by the terms "up", "down", "vertical direction", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the common meanings understood by persons with ordinary skills in the field to which the present invention belongs. The term "include" used in the patent application specification and claims of the present invention means that the elements or objects appearing before "include" include the elements or objects listed after "include" and their equivalents, but do not exclude other elements or objects with the same function.

[0029] It should be noted that the downward movement of each component or part is called "downward movement", and the upward movement is called "return movement"; "lateral" refers to the direction perpendicular to the operation direction of the main oil cylinder of the hydraulic press; "normal pressure" refers to the pressure generated by the main oil cylinder of the hydraulic press when the composite cylinder is not working; "high pressure" or "boosting" refers to the pressure generated after the hydraulic booster mechanism boosts the pressure; "outer end of the side pin 11" refers to the end of the side pin 11 away from the side pressure plunger 10. "Pin block 17" refers to the part of the outer end of the side pin 11 that can be inserted into the pin hole 16. "Outward movement of the side pin 11" and "outward movement of the side pin 11" both refer to the movement of the side pin 11 in the direction away from the composite cylinder. "Inward return of the side pin 11" and "retraction of the side pin 11 into the booster plate 1" both refer to the movement of the side pin 11 in the direction of the composite cylinder. "Upper starting point position" and "lower starting point position" refer to the upper top position and lower top position of the pressure cylinder or booster cylinder.

[0030] Example 1 The specific structure of this embodiment is described in detail below with reference to the accompanying drawings. Figure 1 As shown, this embodiment provides a hydraulic boosting mechanism, which includes a boosting plate 1, a composite cylinder arranged inside the boosting plate 1 for boosting the hydraulic press, and a lateral locking mechanism for locking the position of the boosting plate 1.

[0031] In this embodiment, the composite cylinder includes an upper small-diameter pressure cylinder and a lower large-diameter booster cylinder. A pressure piston 7 is installed in the pressure cylinder. The pressure piston 7 is installed on the movable crossbeam of the hydraulic press through its upper piston rod. In other embodiments, the upper piston rod of the pressure piston 7 can also be connected to the piston rod of the main cylinder of the hydraulic press; the pressure piston 7 and its upper piston rod are sealed with the pressure cylinder through a sliding sealing ring.

[0032] In this embodiment, a boosting piston 2 is installed in the boosting cylinder, the upper end piston of the boosting piston 2 is sealed with the boosting cylinder through a sliding sealing ring, the lower end piston rod of the boosting piston 2 is sealed with the cylinder cover 12 through a sliding sealing ring, the cylinder cover 12 is fixedly connected to the boosting plate 1, the bottom of the boosting piston 2 is fixedly connected to the connecting plate 13, and the lower end of the connecting plate 13 is used to install the upper mold 14, which is corresponding to the lower mold 15 set on the lower cross beam 6.

[0033] The composite cylinder is divided into an upper chamber a of the composite cylinder, a composite chamber c, and a lower chamber b of the composite cylinder by the pressure piston 7 and the booster piston 2. The upper chamber a of the composite cylinder and the lower chamber b of the composite cylinder are controlled by the hydraulic system of the hydraulic press. The composite chamber c is supplied with oil by the hydraulic system and is controlled by a one-way valve 9 to prevent reverse leakage.

[0034] In this embodiment, the lateral locking mechanism includes a side pin assembly arranged on the side of the boost plate 1, and a constraint vertical plate 5 arranged on both sides of the side pin assembly and rigidly connected to the lower cross beam 6 of the hydraulic press; the side pin assembly includes a side pressure cylinder d installed in the boost plate 1 and symmetrically arranged on both sides of the composite cylinder, a side pressure plunger 10 installed in the side pressure cylinder d, and a side pin 11 fixedly connected to the side pressure plunger 10; the side pin 11 is constrained by the sliding fit of the guide plate 4 and is installed in the boost plate 1 through the spring 3.

[0035] There are restraint structures on the opposite sides of the side pin assembly and the restraint vertical plate 5. When the pressure of the side pressure cylinder d is greater than the elastic force of the spring 3, the side pin 11 moves outward to lock the restraint structure, thereby locking the booster plate 1 so that it does not move upward and backward when subjected to the forming force, thereby enabling the hydraulic booster mechanism to play a boosting role.

[0036] A guide column 8 is axially mounted between the pressure piston 7 and the booster piston 2. Figure 1 As shown. In this embodiment, the guide post 8 is fixedly installed on the boosting piston 2, and the upper end of the guide post 8 is slidably connected with the guide post hole on the pressure piston 7. Along the matching portion between the two, an axial groove (not shown in the figure) is provided on the guide post or in the guide post hole, which can connect the guide post hole with the composite chamber c. By installing the guide post 8, the pressure piston 7 and the boosting piston 2 are precisely guided and connected, the connection rigidity is increased, and the rotation of the boosting piston 2 can be avoided; when the height of the composite cylinder and the boosting plate is limited, the piston rods of the two pistons are combined with the guidance of the composite cylinder to increase the guide length, which can effectively avoid the piston deflection phenomenon and improve the anti-eccentric load capability.

[0037] Example 2 This embodiment provides a hydraulic boosting method, which is implemented by the hydraulic boosting mechanism described in Embodiment 1 and includes three working modes: Mode 1: Normal pressure forming action: the upper chamber a of the pressure cylinder is filled with oil, the lower chamber b of the booster cylinder is discharged, the pressure piston 7 and the booster piston 2 are both at the lower starting point position, and mechanical contact is formed between the cylinder head 12; in the subsequent forming process, the side pressure cylinder d and the composite cylinder are not working, and the hydraulic press works in a non-boosting mode. Its action process and effect are the same as those of the hydraulic press before the transformation, and its pressure is determined by the inner diameter of the main oil cylinder 1 of the hydraulic press and the pressure oil pressure provided by the hydraulic system; Mode 2: Boosting and forming action: oil enters the lower chamber b of the boosting cylinder, and oil is discharged from the upper chamber a of the pressure cylinder. The boosting piston 2 and the pressure piston 7 are both at the upper starting position; when the hydraulic press moves downward to the pressure position, oil enters the side pressure cylinder d, and the side pressure plunger 10 drives the side pin 11 to move outward, so that the constraint structure is locked and the boosting plate 1 is locked; the hydraulic press moves downward under pressure, and the pressure piston 7 moves downward (the upper chamber a of the pressure cylinder is filled with oil), and the pressure transmission of the hydraulic oil in the composite cylinder causes the boosting piston 2 to move downward (the back pressure oil is discharged from the lower chamber b of the boosting cylinder), and the boosting and forming action is performed, and the boosting multiple is the ratio of the area of ​​the boosting piston 2 to the area of ​​the pressure piston 7; Method three, pressure-changing forming action: first perform the normal pressure forming action of method one. When the pressure reaches a certain value, change the action of the hydraulic booster mechanism so that the booster piston 2 and the pressure piston 7 return to the upper starting position, and the side pressure plunger 10 drives the side pin 11 to move outward and lock it with the restraining vertical plate 5. The hydraulic press increases pressure and moves downward to complete the booster forming action.

[0038] It should be explained that in the second method, when the small-diameter pressure piston 7 applies pressure to the composite cylinder, the large-diameter booster piston 2 can generate a larger working pressure, and its boosting ratio is equal to the ratio of the cross-sectional area of ​​the booster piston 2 to the pressure piston 7; for example: the diameter of the pressure piston 7 is set to d 1. The diameter of the booster piston 2 is d 2, then the pressure increase ratio in the hydraulic pressure boosting mechanism is n for n = d 2 2 / d 1 2 like d 2=3 d 1, the boost ratio can reach 9.

[0039] Under the condition that the structure size of the booster plate 1 allows, the d 1 and d 2 size, thereby reducing the pressure of the pressure-transmitting medium of the composite cylinder and improving its sealing performance.

[0040] It should be noted that when the pressure-boosting forming action of the second mode is performed, the action process of this embodiment is as follows: Step 1: The hydraulic press works to drive the booster plate 1 downward rapidly, and the movement speed is controlled by the hydraulic system of the hydraulic press; Step 2: When the upper die 14 and the lower die 15 are closed, the position sensor (not shown in the figure, originally in the hydraulic press) sends a signal, the booster plate 1 stops moving, the side pressure cylinder d is filled with oil, the side pin 11 moves outward to lock the restraining structure, and the booster plate 1 is locked; Step 3: The hydraulic press drives the pressure piston 7 to continue to move downward, the oil pressure of the composite cylinder increases, and the booster piston 2 drives the connecting plate 13 and the upper die 14 downward, generating high-pressure extrusion molding; Step 5: When the hydraulic press returns, the oil pressure of the compound cylinder drops to 0, the side pressure cylinder d discharges oil, and the side pin 11 retreats under the elastic force of the spring 3, so that the restraint structure is separated; Step 6: The hydraulic press continues to return, the pressure piston 7 retreats, the upper chamber a of the pressure cylinder discharges oil, the lower chamber b of the booster cylinder enters oil, and the booster piston 2 returns slowly; when the pressure piston 7 returns to the upper starting point, it drives the booster plate 1 and the connected parts to retreat quickly, realizing a rapid return; Step 7: The hydraulic press ejection mechanism works to eject the workpiece, completing a forming process.

[0041] From the above, it can be seen that the entire hydraulic booster mechanism can move up and down quickly driven by the hydraulic press, which is convenient for process operation; when performing the forming action, it has the characteristics of high pressure and stable and slow downward movement, which meets the process requirements for plastic forming.

[0042] Example 3 The restraining structure adopts the cooperation of the pin block 17 and the pin hole 16. Figure 2 a is a schematic transverse cross-sectional view of the side pin 11 and the guide plate 4, Figure 2 b shows a side cross-sectional view of the side pin 11 and the guide plate 4, Figure 2 c is a schematic diagram of the structure of the pin hole 16 arranged on the restraining vertical plate 5. Figure 2 a-2b, the outer end of the side pin 11 has a pin block 17, please refer to Figure 2 c. A plurality of pin holes 16 are arranged in a matrix on the constraint plate 5. Figure 2 As shown, the pin block 17 can cooperate with the pin holes 16 at different positions on the restraining plate 5 along the height direction to restrain the booster plate 1 at different height positions. The size of the pin block 17 and the pin hole 16 can be determined according to the forming force required by the equipment, the number of pin blocks 17 and the allowable stress of the material; the periphery of the pin hole 16 on the restraining plate 5 is also correspondingly provided with a frame Q of the same strength.

[0043] Since the pin hole 16 and the upper and lower frames Q have a relatively high height, the distance that the pin block 17 travels when moving up and down in the adjacent pin holes 16 is relatively long. When the position of the hydraulic booster mechanism generating the boosting action is uncertain, the booster piston 2 has a certain distance from the upper starting point position to the boosting position that can be generated, that is, the booster mechanism needs a relatively large idle stroke before generating the boosting effect. Therefore, it is necessary to increase the height of the composite cylinder and the booster plate 1 accordingly. This structure is used when designing a new hydraulic press or for a hydraulic press with a larger mold opening space; or when mass-producing a type of product, the booster force point of the mold should coincide with the locking position of the side pin assembly.

[0044] Example 4 refer to Figure 3 The difference between this embodiment and embodiment 2 is that the constraint structure further includes a side pin sawtooth N provided at the outer end of the side pin 11 (please refer to Figure 3 a), and the vertical plate serrations M provided on the inner side of the restraining vertical plate 5 (please refer to Figure 3 b), the upper surface of the side pin serration N has a very small cone angle with the horizontal direction, and the lower surface of the serration has a larger cone angle with the horizontal direction; the vertical plate serration M matches the shape of the side pin serration N. When the two serrations are locked, the side pin serration N is aligned with the tooth groove of the vertical column serration M. After locking, the upper surface of the side pin serration N cooperates with the lower surface of the vertical column serration M to generate a longitudinal locking force. The side pin serration N at the outer end of the side pin 11 can be locked with the vertical plate serration M on the constraining vertical plate 5 at different heights. The serration shape is small, and the thickness of the serration (the thickness at 1 / 2 of the serration height) is determined according to the forming force required by the equipment, the number of serrations on the side pin 11, and the shear allowable stress of the material. Since there are more serrations, the tooth shape is smaller, and there is no frame restriction, the side pin assembly and the booster plate 1 move a small distance from one tooth on the constraint vertical plate 5 to the next tooth, that is, the booster plate 1 can produce a high precision boost stroke position, and thus, from the locking of the constraint structure to the boost forming, the downward idle stroke of the booster piston 2 is very small, so that the structure of the composite cylinder is compact and the height of the booster plate 1 is reduced. This method is particularly suitable for boosting modification of old presses and for forming molds of different heights.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A hydraulic booster mechanism, mounted on a hydraulic press, characterized in that: The hydraulic booster mechanism comprises a booster plate, a lateral locking mechanism for locking the position of the booster plate, and a composite cylinder arranged in the booster plate for boosting the hydraulic press, the composite cylinder comprising an upper small-diameter pressure cylinder and a lower large-diameter booster cylinder, the pressure cylinder being provided with a pressure piston, the piston rod of which is fixed on the movable crossbeam of the hydraulic press or mechanically connected to the piston rod of the main oil cylinder of the hydraulic press; the booster cylinder being provided with a booster piston, the piston rod at the lower end of the booster piston being mechanically connected to a connecting plate, the connecting plate being used to connect the mold; the composite cylinder is divided into an upper pressure cylinder chamber, a composite chamber, and a lower booster cylinder chamber by the pressure piston and the booster piston, the upper pressure cylinder chamber and the lower booster cylinder chamber being controlled by the hydraulic system of the hydraulic press; the composite chamber is connected to the hydraulic system of the hydraulic press via a one-way valve; The lateral locking mechanism includes a side pin assembly and a constraint vertical plate rigidly connected to the lower cross beam of the hydraulic press. The side pin assembly and the constraint vertical plate have constraint structures on the opposite sides. When the side pin assembly is moved so that the constraint structure is in a locked state, the booster plate can be locked so that it does not produce an upward backward movement when subjected to forming force.

2. A hydraulic booster mechanism according to claim 1, characterized in that: The pressure piston and the booster piston are guided by guide pillars.

3. A hydraulic booster mechanism according to claim 1, characterized in that: The side pin assembly includes a side pressure cylinder arranged in the booster plate and symmetrically arranged on both sides of the composite cylinder, a side pressure plunger installed in the side pressure cylinder, a side pin fixedly connected to the side pressure plunger, and a spring for returning the side pin inward.

4. A hydraulic booster mechanism according to claim 3, characterized in that: The restraining structure comprises an array of pin holes arranged on the inner side surface of the restraining vertical plate, and a plurality of rows of pin blocks arranged at the outer ends of the side pins and having shapes and positions consistent with the pin holes.

5. A hydraulic booster mechanism according to claim 3, characterized in that: The constraint structure includes a vertical plate serration arranged on the inner side surface of the constraint vertical plate, and a side pin serration arranged on the outer end of the side pin and matching the shape of the vertical plate pin serration. The side pin serration can be locked with the vertical plate serrations of different heights. When the side pressure cylinder is working, the side pressure plunger drives the side pin to move outward, so that the side pin serrations are locked with the vertical plate serrations, generating a locking force in the vertical direction, thereby locking the position of the booster plate.

6. A hydraulic booster mechanism according to claim 3, characterized in that: Guide plates for guiding and restraining the side pins are symmetrically connected to both sides of the boost plate.

7. A hydraulic boosting method, characterized in that: The hydraulic boosting method is implemented by the hydraulic boosting mechanism according to any one of claims 1 to 6, and has three working modes: Mode 1: Normal pressure forming action: oil enters the upper chamber of the pressure cylinder, oil is discharged from the lower chamber of the booster cylinder, the pressure piston and the booster piston are both at the lower starting point position, so that the pressure piston, the booster piston and the cylinder cover are in mechanical contact, and the cylinder cover is fixed on the booster plate and sealed with the middle and lower part of the booster piston; when the press moves downward, the lateral locking mechanism and the composite cylinder do not work, and the hydraulic press works in a non-boosting mode, that is, the hydraulic press works in the original pressure and forming mode; Method 2: Boosting and forming action: oil is introduced into the lower chamber of the boosting chamber, and oil is discharged from the upper chamber of the pressure cylinder, so that both the boosting piston and the pressure piston are at the upper starting position; when the hydraulic press moves downward to the force-increasing position, the position sensor sends a signal, the boosting plate stops moving, oil is introduced into the side pressure cylinder, and the side pin moves outward to lock the restraining structure, and the boosting plate is locked; the hydraulic press drives the pressure piston downward, and the pressure of the hydraulic oil in the composite cylinder is transmitted to make the boosting piston move downward to perform boosting and forming action. The boosting multiple of the hydraulic press is the ratio of the area of ​​the boosting piston to the area of ​​the pressure piston; Method three, pressure-changing forming action: first perform the normal pressure forming action of method one; when pressed down to a certain position, the position sensor sends a signal to change the action of the hydraulic booster mechanism, so that the booster piston and the pressure piston both return to the upper starting point, and the side pin moves outward to lock the constraint structure and lock the booster plate; the hydraulic press continues to pressurize and move downward to complete the booster forming action.

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