A hydraulic press with hydraulic boosting function

Abstract

A hydraulic press with a hydraulic boosting function includes a frame, a hydraulic cylinder assembly mounted on the frame, and a hydraulic system. The hydraulic cylinder assembly is composed of a main hydraulic cylinder, a boosting cylinder, and a control cylinder from bottom to top. The boosting piston of the boosting cylinder is provided with a main oil circuit connecting the oil inlet and the upper chamber of the main hydraulic cylinder. The pressure oil output by the hydraulic system is introduced into the upper chamber of the main hydraulic cylinder through the main oil circuit, and drives the piston of the main hydraulic cylinder to move. The control cylinder is driven by the hydraulic system. The control piston blocks the oil passage during the downward movement of the control piston, so that the upper chamber of the main hydraulic cylinder is isolated from the oil circuit of the hydraulic system and a closed hydraulic chamber is formed. The control piston drives the boosting piston to move downward synchronously, pressurizes the closed hydraulic chamber, drives the main hydraulic cylinder to output power, and causes the hydraulic press to produce a boosting action. This solution can generate a large working pressure and has a large rapid mold opening and closing stroke to meet the needs of plastic forming of large metal parts.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic forming equipment, in particular to a hydraulic press with a hydraulic boosting function. Background Art

[0002] At present, when hydraulic presses are used for precision forming of large metal parts such as extrusion, precision forging, and liquid die forging, a large forming force is often required to meet the requirements of material deformation; at the same time, a large working stroke is required to meet the requirements of mold opening space. In general, a large hydraulic press is used to solve the problem. The main method for large hydraulic presses with large strokes and large pressures is to increase the pressure of the hydraulic press by increasing the diameter or number of hydraulic cylinders, and to increase the stroke of the hydraulic press by increasing the height of the hydraulic cylinders. However, the large-diameter hydraulic cylinder structure will inevitably cause the hydraulic press to have a large structure, high price, complex hydraulic system, difficult installation and maintenance, and low working speed, which greatly increases the production cost. There is also a method of increasing liquid pressure, which will inevitably put higher requirements on the hydraulic system, greatly increase its manufacturing and design costs, and the excessive pressure on the hydraulic system will cause pipeline leakage, control component failure, and high maintenance costs in the later stage.

[0003] Using conventional boosting mechanisms to increase pressure is a common method for hydraulic mechanisms, but it will greatly increase the height of the hydraulic cylinder, and is even more powerless for hydraulic presses with large strokes; there is also a method of using double hydraulic cylinders in series to increase pressure, and the height of the hydraulic cylinders is doubled. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a hydraulic press with a hydraulic booster function. This solution can generate a large working pressure and has a fast mold opening and closing stroke to meet the needs of plastic forming of large metal parts.

[0005] The technical solution adopted by the present invention is: a hydraulic press with a hydraulic booster function, comprising a frame, a hydraulic cylinder assembly installed on the frame and a hydraulic system, wherein the hydraulic cylinder assemblies are, from bottom to top, a main hydraulic cylinder, a booster cylinder and a control cylinder, a booster piston of the booster cylinder is provided with a main oil circuit connecting an oil inlet and an upper chamber of the main hydraulic cylinder, the hydraulic oil output by the hydraulic system is introduced into the upper chamber of the main hydraulic cylinder through the main oil circuit, and drives the piston of the main hydraulic cylinder to move, the control cylinder is driven by the hydraulic system, and the main oil circuit is blocked when the control piston moves downward, so that the upper chamber of the main hydraulic cylinder is isolated from the oil circuit of the hydraulic system and a closed hydraulic chamber is formed, the control piston and the booster piston move downward synchronously, pressurize the closed hydraulic chamber, drive the main hydraulic cylinder to output power, and make the hydraulic press produce a booster action.

[0006] As a preferred solution, the lower chambers of the master hydraulic cylinder, the booster cylinder and the control cylinder are connected to the hydraulic system through independent oil holes respectively.

[0007] As a preferred solution, the control cylinder adopts a hydraulic cylinder structure with a boosting function.

[0008] As a preferred solution, an oil hole connecting the oil inlet and the upper chamber of the booster cylinder is provided in the control piston of the control cylinder, and the lower end of the oil hole is connected to the upper chamber of the booster cylinder through the hole on the side wall of the control piston.

[0009] As a preferred solution, the upper chamber of the control cylinder is connected to the hydraulic system through an oil hole. The oil hole, the oil hole of the control piston and the oil hole of the booster piston form a main oil circuit, which can guide the hydraulic oil of the hydraulic system into the upper chamber of the master hydraulic cylinder.

[0010] As a preferred solution, the upper chamber of the booster cylinder is connected to the hydraulic system through an oil hole, and the oil hole and the oil hole of the booster piston form a main oil circuit, which can guide the hydraulic oil of the hydraulic system into the upper chamber of the main hydraulic cylinder.

[0011] As a preferred embodiment, a boss structure is provided at the lower end of the control piston, and a groove structure matching the boss structure is provided on the upper surface of the boost piston. The inlet end corresponding to the oil hole of the boost piston is located in the groove structure, and the oil hole in the boost piston is opened or blocked by driving the control piston up or down.

[0012] As a preferred solution, the lower end of the piston rod of the control piston has a convex frustum structure, and the upper surface of the booster piston has a concave frustum structure. The inlet end corresponding to the oil hole of the booster piston is located in the concave frustum structure. The convex frustum structure and the concave frustum structure constitute a follower cone valve mechanism. When the follower cone valve mechanism is open, the hydraulic oil of the hydraulic system flows directly into the upper chamber of the master hydraulic cylinder through the main oil circuit; when the follower cone valve mechanism is closed, the upper chamber of the master hydraulic cylinder is isolated from the main oil circuit between the hydraulic system.

[0013] The beneficial effects of the present invention are:

[0014] First, this solution is optimized in design, specifically: the hydraulic cylinder components are, from bottom to top, a main hydraulic cylinder, a booster cylinder and a control cylinder. The booster piston of the booster cylinder is provided with a main oil circuit connecting the oil inlet and the upper chamber of the main hydraulic cylinder. The hydraulic oil output by the hydraulic system is introduced into the upper chamber of the main hydraulic cylinder through the main oil circuit, and drives the piston of the main hydraulic cylinder to move. The control cylinder is driven by the hydraulic system. When the control piston moves downward, the oil circuit is blocked, so that the upper chamber of the main hydraulic cylinder is isolated from the oil circuit of the hydraulic system to form a closed hydraulic chamber. The control piston and the booster piston move downward synchronously, pressurize the closed hydraulic chamber, drive the main hydraulic cylinder to output power, and make the hydraulic press produce a boosting action. This result has the following advantages: the hydraulic system provides power for the rapid downward and return movement of the main hydraulic cylinder. When high-pressure output is required, the hydraulic system can drive the control cylinder to close the oil circuit of the upper chamber of the main hydraulic cylinder, and the booster cylinder provides high-pressure pressure for the main hydraulic cylinder, and the hydraulic press produces a booster action. At the same time, when high-pressure output is achieved, the upper chamber of the main hydraulic cylinder has formed a closed hydraulic chamber, and the high-pressure chamber of the hydraulic cylinder is completely isolated from the hydraulic system. Therefore, all components of the hydraulic system operate under low pressure and normal pressure, with high safety, no leakage, and long service life. Secondly, the high-pressure and low-pressure switching of the main hydraulic cylinder in this scheme is active, and it can be switched from low pressure to high pressure, or from high pressure to low pressure at any time, and has good applicability.

[0015] Furthermore, the piston of the control cylinder has the function of boosting while opening and closing the boosting cylinder, so that the boosting of double boosting cylinders can be realized, and the boosting multiple is large; under the same boosting multiple, the diameter of the boosting cylinder can be reduced; under the same equipment pressure (tonnage) conditions, the diameter of the main hydraulic cylinder used in this scheme is much smaller than the diameter of the hydraulic cylinder in the current large hydraulic press, which can effectively reduce the size of the equipment, because the large-tonnage press and the beam size will be constrained by the diameter of the hydraulic cylinder and cannot be made smaller, and the reduction of the hydraulic cylinder diameter can reduce the beam size, and the thickness of the beam can also be reduced accordingly, so the manufacturing cost is significantly reduced, and because the pressure working stroke of plastic forming is much smaller than the no-load stroke, the stroke of the boosting piston does not need to be too large, and the existence of the boosting piston makes the axial size of the hydraulic cylinder change little, and the structure is relatively compact. Therefore, the equipment cost can be significantly reduced.

[0016] Second, in this solution, a main hydraulic cylinder with a smaller diameter is used. When the press machine is moving down and back quickly, the required oil supply is small, which can speed up the movement speed and reduce the power requirements of the hydraulic system. When it is moving down without load and at normal pressure (hydraulic system pressure), the booster piston does not move, and only moves when boosting. Since most of the general hydraulic presses are working (plastic forming) without load and moving at normal pressure, the high-pressure forming distance is very short, so the height of the booster cylinder can be made very small, and the oil supply required during operation is also significantly reduced compared with conventional booster systems.

[0017] Third, it can perform fast no-load descending, slow mold closing and pressurizing to avoid impact on the mold; when returning, it can first release the pressure to open the mold slowly, and then return quickly. This shows that this hydraulic press has the characteristics of "fast descending, slow pressurizing, slow pressure relief, and fast return", which is conducive to improving production efficiency and energy saving, and the action is continuous and easy to operate.

[0018] Fourth, under normal circumstances, high pressure forming (plastic forming of the blank) requires the main hydraulic cylinder to move downward slowly, and the oil supply power of the hydraulic system is small, thereby reducing the complexity and cost of the hydraulic system, and significantly reducing the operating cost, which has obvious economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a hydraulic press in a first embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of a hydraulic cylinder assembly in a second embodiment of the present invention;

[0021] Figure 3 It is a schematic structural diagram of a hydraulic cylinder assembly in a third embodiment of the present invention.

[0022] Figure numerals: 1. Control cylinder, 1′. Upper cylinder head, 2. Booster cylinder, 2′. Combination cylinder, 3. Main hydraulic cylinder, 4. Lower cylinder head, 5. Control piston, 6. Booster piston, 7. Main piston, 21. Upper crossbeam, 22. Movable crossbeam, 23. Column, 24. Lower crossbeam, 25. Ejector cylinder, a, b, c, d, e, f. Oil holes, m, n, o, p, q, r. Oil chambers. DETAILED DESCRIPTION

[0023] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that, without further description, elements, structures and features in one embodiment may also be beneficially combined in other embodiments.

[0024] It should be noted that, unless otherwise defined, the technical terms or scientific terms used herein shall have the common meanings understood by persons with ordinary skills in the field to which the present invention belongs. "Including" and similar words indicate that the elements or objects appearing before "including" include the elements or objects listed after "including" and their equivalents, but do not exclude other elements or objects with the same function.

[0025] The downward movement of each component or part is called "downward", and the upward movement is called "return"; "low pressure" refers to the pressure output by the hydraulic system, and "high pressure" refers to the pressure generated after the booster cylinder boosts the pressure; "oil supply" refers to the hydraulic system delivering hydraulic oil to the hydraulic chamber of the hydraulic cylinder through the oil circuit, "oil return" refers to the hydraulic oil in the hydraulic chamber flowing back to the oil tank of the hydraulic system through the oil circuit, and "oil suction" refers to the hydraulic oil in the oil tank of the hydraulic system being sucked into the hydraulic chamber through the oil circuit.

[0026] The following is combined with Figure 1-3 The specific structures of three embodiments of the present invention are described in detail:

[0027] Embodiment 1,

[0028] In this embodiment 1, a hydraulic press with a hydraulic boosting function, such as Figure 1 As shown, it includes a main machine and a hydraulic system for controlling the main machine. The main machine includes a frame composed of an upper crossbeam 21, a movable crossbeam 22, a column 23, and a lower crossbeam 24, a hydraulic cylinder assembly installed on the upper crossbeam 21, and an ejection cylinder 25 installed on the lower crossbeam 24.

[0029] In this embodiment, the hydraulic cylinder assembly includes a control cylinder 1, a booster cylinder 2, a main hydraulic cylinder 3, and a lower cylinder cover 4, which are fixedly connected by screws;

[0030] A control piston 5 is installed in the control cylinder 1 in cooperation with a sliding seal, and the control cylinder is divided into an upper chamber m and a lower chamber n by the control piston 5; a booster piston 6 is installed in the booster cylinder 2 in cooperation with a sliding seal, and the booster cylinder is divided into an upper chamber o and a lower chamber p by the booster piston 6; a main piston 7 is installed in the main hydraulic cylinder 3 in cooperation with a sliding seal, and the main hydraulic cylinder is divided into an upper chamber q and a lower chamber r by the main piston 7;

[0031] The control piston 5, the booster piston 6, the main piston 7 and the cylinder wall are slidably sealed by sealing rings; the piston rod of each piston and the cylinder body or the cylinder head are slidably sealed by sealing rings; and fixed seals are used between the cylinder bodies or between the cylinder bodies and the cylinder heads.

[0032] The hydraulic system is connected with the upper oil chamber m of the control cylinder through the oil hole a, and with the lower oil chamber n of the control cylinder through the oil hole b; it is connected with the upper oil chamber o of the booster cylinder through the oil hole c, it is connected with the lower oil chamber p of the booster cylinder through the oil hole d, and it is connected with the lower oil chamber r of the master cylinder through the oil hole f.

[0033] An oil hole e is provided in the booster piston 6, through which the upper chamber o of the booster cylinder is connected with the upper chamber q of the master hydraulic cylinder. The oil hole c and the oil hole e constitute a main oil circuit. When the main oil circuit is connected, the hydraulic oil of the hydraulic system directly enters the upper chamber q of the master hydraulic cylinder 3 through the main oil circuit, pushing the master piston 7 downward;

[0034] The lower end of the piston rod of the control piston 5 is provided with a convex frustum structure, and the upper surface of the booster piston 6 is provided with a concave frustum structure, which is consistent with the shape of the convex frustum structure of the control piston 5. When the convex frustum contacts the concave frustum, the oil hole e can be blocked, that is, the main oil circuit is blocked, thereby achieving sealing of the upper chamber q of the master hydraulic cylinder.

[0035] Based on the above analysis, it can be understood that the convex cone structure of the piston rod of the control piston 5 and the concave cone structure on the booster piston 6 form a follower cone valve mechanism. When the control cylinder 1 is not working, the follower cone valve mechanism is opened, which will open the oil hole e, and the hydraulic oil of the hydraulic system can directly flow into the upper chamber q of the main hydraulic cylinder through the main oil circuit, so that the main piston 7 moves downward, and the hydraulic machine moves downward quickly and at low pressure; when the oil hole a supplies oil and the oil hole b returns oil, the control piston 5 moves downward, so that the follower cone valve mechanism is closed, the main oil circuit is disconnected, and the hydraulic oil of the hydraulic system enters the upper chamber o of the booster cylinder 2 through the oil hole c, and the oil hole d discharges oil, and the booster piston 6 moves downward, applying high pressure to the upper chamber q of the main hydraulic cylinder 3, so that the main piston 7 moves downward, and the hydraulic machine moves downward at high pressure. This shows that the follower cone valve mechanism is opened and closed by the action of the control piston, and then the on-off of the main oil circuit is controlled to achieve pressure control of the main hydraulic cylinder.

[0036] The control method of the hydraulic press for high-pressure plastic forming of a workpiece, the forming action is as follows:

[0037] When the hydraulic press stops working, the hydraulic system blocks the oil holes a, b, c, d, and f.

[0038] 1) The hydraulic press moves downward quickly: the oil hole f opens, the filling valve leading to the oil hole c opens, the main piston 7 moves downward quickly by gravity, the hydraulic oil in the oil tank quickly flows into the upper chamber q of the main hydraulic cylinder 3 through the main oil path composed of the oil holes c, e and the oil chamber 0, and the hydraulic oil in the lower chamber r flows back to the oil tank through the oil hole f;

[0039] 2) The hydraulic press moves downward slowly: the filling valve of the hydraulic system is closed, the hydraulic oil slowly enters the upper chamber r of the booster cylinder through the main oil circuit, the main piston 7 moves downward slowly, and the hydraulic oil in the lower chamber r flows back to the oil tank through the oil hole f;

[0040] 3) Hydraulic press low-pressure forming: The mold installed on the hydraulic press is closed, the system pressure is increased to the system working pressure, the hydraulic system is supplied with oil normally, and the blank is formed under low pressure;

[0041] 4) Hydraulic press high-pressure forming: oil hole a is connected to supply oil, oil hole b returns oil, and the pressure of oil chamber m forces the control piston 5 to move downward, the follower cone valve mechanism is closed, and the main oil circuit is disconnected; at the same time, oil hole e returns oil, and oil chambers m and o are in a pressure state, causing the control piston 5 and the booster piston 6 to move downward synchronously, applying pressure to the closed hydraulic chamber q, forcing the main piston 7 to move downward, generating high pressure on the workpiece to form it;

[0042] Among them, since the control piston 5 is only used as a follower cone valve mechanism, the diameter D 1 is very small, and the boosting effect that can be produced is limited and can be ignored. Therefore, the boosting multiple of the boosting cylinder in this embodiment is n for

[0043] n = D 2 2 / d 2 2

[0044] like D 2=2 d 2, then,

[0045] n =4

[0046] This embodiment uses a small-diameter control cylinder, which can reduce the cost of the hydraulic cylinder;

[0047] During the pressurized forming process, with the same oil supply, the downward speed of the main hydraulic cylinder is 1 / 2 of that of the low-pressure downward speed. n , so as to achieve the purpose of slow pressing and forming.

[0048] 5) Hydraulic press decompression: oil enters from oil hole b and returns from oil hole a, controlling the return stroke of piston 5 and decompressing the oil chamber q until the follower cone valve mechanism opens and the main oil circuit is connected.

[0049] 6) Rapid return of hydraulic press: oil enters through oil holes b, d, and f, oil returns through oil holes a and c, control piston 5 and booster piston 6 return, and main piston 7 returns rapidly.

[0050] Embodiment 2,

[0051] like Figure 2 As shown, a hydraulic press with a hydraulic boosting function has a structure that is basically the same as that of Example 1, except that the diameters of the control cylinder and the control piston are enlarged so that the control cylinder has the function of a boosting cylinder, and together with the boosting cylinder below, it forms a dual boosting cylinder boosting output, which has the characteristic of a large boosting multiple.

[0052] In this embodiment, the diameter of the control cylinder is increased to the same diameter as the boost cylinder and is made into an integral structure with the boost cylinder to form a combined cylinder 2', and an upper cylinder cover 1' is added. The working principle is the same as that of the first embodiment.

[0053] In order to describe this embodiment more clearly, the upper cylinder in the combined cylinder 2' is defined as the control cylinder, and the lower cylinder is defined as the booster cylinder;

[0054] In this embodiment, the diameter of the control cylinder is D 1. The piston rod diameter of the control piston 5 isd 1. The diameter of the booster cylinder is D 2. The piston rod diameter of the booster piston 6 is d 2. When the M chamber is pressurized and the O chamber is not pressurized, only the control piston plays a role in increasing pressure. n for

[0055] n = D 1 2 / d 2 2

[0056] like D 1=2 d 2, then,

[0057] n =4

[0058] When chamber m and chamber o are pressurized at the same time, and chamber n and chamber p return oil, then the pressure increase multiple is n for

[0059] n =[ D 1 2 +( D 2 2 - d 1 2 )] / d 2 2

[0060] like D 1= D 2=2 d 1=2 d 2, then,

[0061] n =7

[0062] Embodiment 3,

[0063] In this embodiment, a hydraulic press with a hydraulic boosting function, such as Figure 3 As shown, the basic structure is substantially the same as that of Embodiment 2, except that the local oil circuit is different.

[0064] In order to describe this embodiment more clearly, the upper cylinder in the combined cylinder 2' is defined as the control cylinder, and the lower cylinder is defined as the booster cylinder;

[0065] Compared with Example 2, Example 3 removes the oil hole c leading to the hydraulic system from the upper chamber o of the boosting cylinder, and replaces it in the control piston 5. Specifically, an oil hole c is provided in the control piston 5. The lower end of the oil hole c is not straight, but has multiple side holes opened from the side wall. The upper chamber m of the control cylinder is connected with the upper chamber o of the boosting cylinder through the oil hole c. The oil holes a, c, and e constitute the main oil circuit for the hydraulic oil to enter the upper chamber q of the main hydraulic cylinder.

[0066] The forming action of this embodiment is as follows:

[0067] When the hydraulic press stops working, the hydraulic system blocks the oil holes a, b, d, and f.

[0068] 1) The hydraulic press moves downward quickly: the oil hole f opens, the filling valve leading to the oil hole a opens, the main piston 7 moves downward quickly by gravity, the hydraulic oil in the oil tank quickly flows into the upper chamber q of the main oil cylinder through the main oil circuit, and the hydraulic oil in the lower chamber r flows back to the oil tank through the oil hole f;

[0069] 2) The hydraulic press moves downward slowly: the filling valve of the hydraulic system is closed, the hydraulic oil slowly enters the upper chamber of the booster cylinder through the main oil circuit, the main piston 7 moves downward slowly, and the hydraulic oil in the lower chamber r flows back to the oil tank through the oil hole f;

[0070] 3) Hydraulic press low-pressure forming: The mold installed on the hydraulic press is closed, the system pressure is increased to the system working pressure, the hydraulic system is supplied with oil normally, and the blank is formed under low pressure;

[0071] 4) Hydraulic press high-pressure forming: Oil hole b is connected to return oil. Since the area of ​​the control piston is larger than the area of ​​its piston rod, the force of the oil chamber m on the control piston is larger than the force of the o chamber on its piston rod, forcing the control piston 5 to move downward, the follower cone valve mechanism is closed, and the main oil circuit is disconnected. Then, oil returns from the oil hole d, and the oil chambers m and o are in a pressure state, causing the control piston to move downward together with the boost piston, exerting pressure on the closed hydraulic chamber q, forcing the main hydraulic piston 7 to move downward, generating high pressure on the workpiece to form it.

[0072] Assume that the diameter of the control cylinder is D 1. The piston rod diameter of the control piston 5 is d 1. The diameter of the booster cylinder is D 2. The piston rod diameter of the lower booster piston 6 is d 2, then,

[0073] The boost multiple of the boost cylinder n for

[0074] n =[ D 1 2 +( D 2 2 - d 1 2)] / d 2 2

[0075] like D 1= D 2=2 d 1=2 d 2, then,

[0076] n =7

[0077] That is, it has a 7-fold boost factor.

[0078] 5) Hydraulic press decompression: oil enters from oil hole b and returns from oil hole a, controlling the return stroke of piston 5 and decompressing the oil chamber q until the follower cone valve mechanism opens and the main oil circuit is connected.

[0079] 6) Rapid return of the hydraulic press: oil enters through holes b, d, and f, oil returns through hole a, control piston 5 and booster piston 6 return, and main piston 7 returns quickly.

[0080] The above are three embodiments of the present invention. The basic method is that the hydraulic system first supplies oil to the main hydraulic cylinder to make the main hydraulic cylinder move downward quickly. When the main hydraulic cylinder reaches the working position, the piston movement is controlled to close the follower cone valve mechanism, and the main oil circuit is disconnected to make the booster cylinder work, so as to provide high-pressure oil to the main hydraulic cylinder and apply high pressure to the workpiece for slow forming.

[0081] When the follower cone valve mechanism is opened, the main oil circuit is opened, and the hydraulic oil of the hydraulic system can directly flow into the upper chamber q of the main hydraulic cylinder, so that the main piston 7 moves downward, and the hydraulic machine moves downward quickly and at low pressure; when the follower cone valve mechanism is closed, the main oil circuit is blocked, and the hydraulic oil of the hydraulic system enters the upper chambers of the control cylinder and the booster cylinder, and the piston rod of the booster cylinder presses the main hydraulic cylinder, so that the main piston 7 moves downward, and the hydraulic machine moves downward at high pressure. The follower cone valve mechanism is opened and closed by the control cylinder, so that the pressure control of the oil chamber q by the hydraulic system is realized.

[0082] From the above, it can be seen that the hydraulic press with a boosting function of the present invention can achieve rapid up and down movement, has a large mold opening and closing stroke, and is convenient for process operation; when performing forming movement, it has a large boosting effect and a slower downward speed, which meets the process requirements for plastic forming.

[0083] Furthermore, the high-pressure forming action is actively generated by controlling the pressure of the booster cylinder. When the hydraulic press descends quickly, when it descends slowly, when it forms at low pressure, when it forms at high pressure, etc., can all be automatically controlled by the hydraulic system. The hydraulic press of the present invention can perform low-pressure forming alone to complete the forming of parts with lower pressure, or it can perform high-pressure forming alone to complete the forming of parts with higher pressure, or it can perform low-pressure forming first and then high pressure forming or high pressure forming first and then low pressure forming. For example, for wheel extrusion forming, a large stroke and no-load descending, a large stroke and low-pressure upsetting process, and a small stroke and high-pressure extrusion forming wheel process are required. The action of first rapid descending, then low-pressure upsetting, and then high-pressure extrusion forming can be adopted; it is also suitable for the situation of first large-pressure preforming and then small-pressure superplastic forming during dynamic superplastic forming. In general, the forming process requires a large idle stroke and a small working stroke, and thus the stroke of the booster cylinder is not large. Therefore, the height of the hydraulic cylinder of the present invention is much lower than that of the hydraulic cylinder of the direct booster or double-cylinder series booster structure.

[0084] In the present invention, except that the upper cavity of the main hydraulic cylinder is under high pressure during high pressure forming, other parts of the hydraulic cylinder and the entire hydraulic system are under low pressure, and the sealing and operating performance of the equipment are not affected.

[0085] The diameter of the booster cylinder in the embodiment of the present invention is the same as the diameter of the main hydraulic cylinder, and the diameter of the booster cylinder may also be smaller than the diameter of the main hydraulic cylinder. The booster piston in the embodiment of the present invention is set to be twice the diameter of the piston rod, and the control piston is set to be twice the diameter of the piston rod. Different settings may also be used in other embodiments.

[0086] Different boosting multiples can be obtained by setting different sizes of boosting pistons and piston rods, but this is affected by the sealing effect between the piston of the main hydraulic cylinder and the cylinder body. In view of the current sealing ring technology, the pressure of the hydraulic cylinder can reach more than 300MPa, so the present invention can achieve a larger boosting multiple to significantly reduce the size of the hydraulic cylinder. At the same time, the power output of the hydraulic system can be reduced accordingly, thereby effectively reducing the equipment cost and the use cost. It has obvious economic and social benefits.

[0087] During the pressurized forming process, with the same oil supply, the downward speed of the main hydraulic cylinder is 1 / 2 of that of the direct oil supply. n , so as to achieve the purpose of slow pressing and forming.

[0088] In the embodiment of the present invention, the bottom of the piston rod of the control piston 5 is set to a convex frustum structure, and the upper surface of the booster piston 6 is set to a concave frustum structure. The two are combined to form a follow-up cone valve mechanism. The bottom of the piston rod of the control piston 5 can also be set to a flat bottom, and the upper surface of the lower booster piston 6 is set to a plane. The bottom surface of the piston rod of the control piston 5 and the corresponding surface of the upper surface of the booster piston 6 form a follow-up flat valve mechanism to realize the opening and blocking of the oil hole e.

[0089] The lower chamber n of the control cylinder of the present invention is connected to the hydraulic system through the oil hole b to control the movement of the piston 5. A spring can also be installed on the piston rod of the lower chamber n to control the return stroke of the piston 5. In this case, the oil hole b may not be connected to the hydraulic system.

[0090] In the embodiment of the present invention, the hydraulic press is applied to plastic forming processing. The hydraulic press can also be used in forming processes of large parts such as liquid die forging and precision forging.

[0091] In this embodiment, the main hydraulic cylinder adopts a piston cylinder, and may also adopt a plunger cylinder, and two small piston cylinders are added at the same time for the rapid downward stroke and return stroke of the press.

[0092] It should be noted that although the present invention is described by the above embodiments, the present invention may also have other various embodiments. Without departing from the spirit and scope of the present invention, it is obvious that those skilled in the art may make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope of protection of the appended claims of the present invention and their equivalents.

Claims

1. A hydraulic press with hydraulic boosting function, characterized in that: The jackup cam of the hydraulic press is annularly arranged in a circle, and the jackup cam is arranged on the upper surface of the hydraulic press, and the jackup cam is arranged on the lower ...

2. A hydraulic press with hydraulic boosting function according to claim 1, characterized in that: The lower chambers of the main hydraulic cylinder, the booster cylinder and the control cylinder are communicated with the hydraulic system through independent oil holes respectively.

3. The hydraulic press with hydraulic boosting function according to claim 1, characterized in that: The control cylinder adopts a hydraulic cylinder structure with a pressure-increasing function.

4. A hydraulic press with hydraulic boosting function according to claim 3, characterized in that: An oil hole communicating with the oil inlet and the upper chamber of the booster cylinder is arranged in the control piston of the control cylinder, and the lower end of the oil hole communicates with the upper chamber of the booster cylinder through the hole on the side wall of the control piston.

5. A hydraulic press with hydraulic boosting function according to claim 4, characterized in that: The upper chamber of the control cylinder is connected to the hydraulic system through an oil hole. The oil hole, the oil hole of the control piston and the oil hole of the booster piston form a main oil circuit, which can guide the hydraulic oil of the hydraulic system into the upper chamber of the main hydraulic cylinder.

6. The hydraulic press with hydraulic boosting function according to claim 3, characterized in that: The upper chamber of the booster cylinder is connected to the hydraulic system through an oil hole. The oil hole and the oil hole of the booster piston form a main oil circuit, which can guide the hydraulic oil of the hydraulic system into the upper chamber of the main hydraulic cylinder.

7. The hydraulic press with hydraulic boosting function according to claim 1, characterized in that: The lower end of the piston rod of the upper booster piston has a convex frustum structure, and the upper surface of the lower booster piston has a concave frustum structure. The inlet end corresponding to the oil hole of the booster piston is located in the concave frustum structure. The convex frustum structure and the concave frustum structure constitute a follower cone valve mechanism. When the follower cone valve mechanism is open, the hydraulic oil of the hydraulic system directly flows into the upper chamber of the master hydraulic cylinder through the main oil circuit; when the follower cone valve mechanism is closed, the upper chamber of the master hydraulic cylinder is isolated from the main oil circuit of the hydraulic system.

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