A hydraulic machine

Abstract

This invention provides a hydraulic press, including a slider with several downward-opening compensation chambers at its bottom. Each compensation chamber houses a compensation cylinder, within which a plunger is slidably housed. A compensation moving plate is positioned below the plunger. A stopper for supporting and limiting the slider is fixedly installed at its bottom, covering the compensation chambers. Each compensation cylinder is connected to an independently pressure-regulating control oil circuit and equipped with a pressure sensor. Driven by a high-pressure medium, the plunger presses downward against the compensation moving plate, applying a reverse bending moment to the slider via the stopper to counteract downward deflection. This invention, by incorporating compensation chambers, compensation cylinders, plungers, and compensation moving plates at the bottom of the slider, utilizes downward pressure to directly apply a reverse bending moment to the bottom of the slider via the stopper. This ensures workpiece flatness, compensates for deformation during high-tonnage, large-worktable pressing, and achieves balanced pressure across the entire surface area. It effectively solves common industry problems such as uneven stress, inconsistent corrugation depth, and poor flatness during metal sheet forming, ensuring stable forming quality.

Description

Technical Field

[0001] This invention relates to the field of hydraulic press technology, and in particular to a hydraulic press with a large table surface, ultra-high pressure, and active deflection compensation function. Background Technology

[0002] In heavy-duty hydraulic pressing equipment, large hydraulic presses inevitably experience lateral downward deflection when subjected to extremely high pressing loads ranging from thousands to tens of thousands of tons. This downward deflection causes gaps in the mold mating surfaces, leading to quality problems such as uneven thickness and out-of-tolerance precision in the pressed parts. Traditional methods often rely on passively changing the position of the hydraulic cylinders or using integral mechanical shims for compensation. These methods not only fail to achieve dynamic and precise control but also struggle to effectively counteract complex bending stresses under heavy-duty off-center or asymmetrical pressing conditions. Furthermore, the sealing of the interface and the high-pressure delivery of the high-pressure medium during the slider deformation process are also technical challenges hindering the high-reliability operation of ultra-high-pressure deflection compensation mechanisms. Summary of the Invention

[0003] The purpose of this invention is to provide a hydraulic press to solve the technical problem that the slider of the existing hydraulic press is prone to downward deflection during the ultra-high pressure pressing process on a large table.

[0004] To achieve the above objectives, the present invention provides a hydraulic press, including a slider. The bottom of the slider has several downward-opening compensation chambers. A compensation cylinder body is disposed within each compensation chamber, and a plunger is slidably housed within the compensation cylinder body. A compensation moving plate is disposed within the compensation chamber and below the plunger, acting on the compensation moving plate when the plunger extends downward. A stop is fixedly disposed at the bottom of the slider, covering the compensation chambers to support and limit the upward movement of the compensation moving plate and the compensation cylinder body. Each compensation cylinder in each compensation chamber is connected to a pressure control oil circuit for individually supplying and regulating the pressure of each compensation cylinder. Each compensation cylinder or its corresponding pressure control oil circuit is equipped with a pressure sensor for real-time detection and feedback of the current pressure signal of the corresponding compensation cylinder. The control system adjusts the output pressure of each compensation cylinder individually based on the feedback signal from the pressure sensor and preset pressing process requirements. The plunger, driven by a high-pressure medium, presses downward against the compensation moving plate, applying a reverse bending moment to the slider via the stop to counteract its downward deflection.

[0005] Furthermore, the stop is an upper pad, which is fixed to the bottom of the slider by bolts; the downward force of the plunger is transmitted to the bottom of the slider in sequence through the compensating moving plate, the upper pad and the bolts, forming a downward pulling force.

[0006] Furthermore, a stepped oil passage hole is provided on the slider body and communicates with the compensation cylinder body; a bridging sealing tube is embedded in the stepped oil passage hole, one end of the bridging sealing tube extends into the oil inlet of the compensation cylinder body, and the other end extends into the oil passage hole of the slider body; a high-pressure resistant sealing element is sleeved on the outer periphery of the bridging sealing tube, the high-pressure resistant sealing element includes an elastic sealing ring and a metal anti-extrusion retaining ring placed on the high-pressure side of the elastic sealing ring; when the high-pressure medium is introduced, the high-pressure medium acts on the high-pressure resistant sealing element to make it expand axially to achieve a self-tightening seal at the interface between the slider body and the compensation cylinder body, and the bridging sealing tube can adaptively absorb the relative micro-displacement between the slider and the compensation cylinder body when the slider deforms.

[0007] Furthermore, the compensation chamber includes a central chamber arranged along the length of the slider and edge chambers located on both sides of the central chamber; the compensation cylinder placed in the central chamber is equipped with a connecting oil pipe passing through the top of the slider; the compensation cylinder placed in the edge chamber is equipped with a lateral ultra-high pressure docking oil inlet assembly introduced from the side of the slider, the lateral ultra-high pressure docking oil inlet assembly includes a connecting seat fixedly installed at the oil inlet channel on the side of the slider and an oil pipe nozzle inserted into the connecting seat.

[0008] Furthermore, one end of the connector forms a plug-in portion, which is fixedly plugged into the oil channel. The plug-in portion has external threads and a wall groove, and the wall groove has a locking block. The inner wall of the oil inlet channel on the side of the slider has internal threads. The screw connection of the external threads and internal threads fixes the connector in the axial direction. The wall groove is fitted with a U-shaped buckle with a through hole. The side of the slider has a threaded hole corresponding to the through hole. After the bolt passes through the through hole, it is screwed into the threaded hole. The locking block rests on the opening of the buckle and is fixed in the circumferential direction.

[0009] Furthermore, the connecting seat has a first conical surface inside, and the oil nozzle has a second conical surface on the outer periphery of the front end. The taper of the first conical surface is greater than that of the second conical surface, so that when the oil nozzle and the connecting seat are axially pressed together, an annular linear sealing contact is formed on the side near the high-pressure oil. The connecting seat is circumferentially hinged with several abutment rods. The hinge center of the abutment rod is offset from the center of the abutment rod to form a long end and a short end. An abutment ring is fixedly provided on the outer periphery of the oil nozzle, and the short end of each abutment rod is movably pressed against the abutment ring. The lateral ultra-high pressure docking oil inlet assembly also includes a locking mechanism sleeved on the outside of the connecting seat. The locking mechanism is used to push the long end of each abutment rod to tilt and swing inward so that the short end of the abutment rod pushes the abutment ring, thereby driving the oil nozzle to axially press against the connecting seat inward.

[0010] Furthermore, the locking mechanism includes a sleeve that is movably fitted onto the outer periphery of the connecting seat and a locking nut that is threadedly connected to the connecting seat; the inner wall of the sleeve is provided with a pressure slope, and when the locking nut is rotated and pushed forward, it pushes the sleeve to move axially, and the pressure slope squeezes the long ends of each abutment rod together.

[0011] Furthermore, the pressure control circuit includes a high-pressure oil supply main pipe and several independent branches that are connected to each of the aforementioned compensation cylinders one by one; each independent branch is equipped with an independent electro-hydraulic proportional pressure regulating valve or servo valve in series; the control system is electrically connected to the control end of each electro-hydraulic proportional pressure regulating valve or servo valve, and is used to adjust the opening of each electro-hydraulic proportional pressure regulating valve or servo valve independently according to the feedback signal of each pressure sensor, so that each compensation cylinder outputs asymmetrical or non-uniform compensation pressure.

[0012] Furthermore, the compensation chambers are arranged in a matrix at the bottom of the slider, with each compensation chamber equipped with a corresponding compensation cylinder body, plunger and compensation moving plate, and each compensation cylinder in the matrix is ​​independently controlled by the pressure control oil circuit.

[0013] Furthermore, the hydraulic press also includes a main cylinder pressure sensor for acquiring the real-time pressure of the main cylinder of the press. The main cylinder pressure sensor is connected to the control system signal. The control system has a preset mapping relationship matrix or proportional coefficient between the main cylinder pressure and the target pressure of each compensation cylinder. During the pressing process, the control system acquires the signal from the main cylinder pressure sensor in real time, and calculates the target set pressure of each compensation cylinder at the current moment based on the mapping relationship matrix or proportional coefficient. Then, it combines the real-time pressure feedback value acquired by the pressure sensor on each compensation cylinder to perform PID closed-loop regulation, driving the pressure control oil circuit to adjust the output pressure, so as to realize the dynamic following of the pressure of each compensation cylinder with the pressure of the main cylinder.

[0014] This invention utilizes a built-in compensation chamber, compensation cylinder, plunger, and compensation moving plate at the bottom of the slider. By applying a reverse bending moment directly to the bottom of the slider through a stop component using the downward pressure force, it ensures the flatness of the workpiece. This compensates for deformation during high-tonnage, large-table pressing, achieving balanced pressure across the entire surface. It effectively solves common industry problems such as uneven stress, inconsistent corrugation depth, and poor flatness during metal sheet forming, ensuring stable forming quality. Combined with a high-pressure linear seal and lever locking mechanism, as well as a bridge-adaptive seal and multi-channel independent closed-loop pressure regulation control system, it achieves active and precise cancellation of the downward deflection deformation of the slider in ultra-high-pressure, large-table hydraulic presses, significantly improving product accuracy and equipment operational stability under ultra-high-pressure pressing conditions. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural schematic diagram of a hydraulic press according to an embodiment of the present invention;

[0016] Figure 2 yes Figure 1 A schematic diagram of the magnified state structure at point I;

[0017] Figure 3 This is a three-dimensional structural diagram of an exploded hydraulic press according to an embodiment of the present invention;

[0018] Figure 4 yes Figure 3 A magnified structural diagram of point II;

[0019] Figure 5 This is a cross-sectional structural schematic diagram of a hydraulic press according to an embodiment of the present invention;

[0020] Figure 6 yes Figure 5 A magnified schematic diagram of the structure at point III;

[0021] Figure 7 yes Figure 5 A magnified structural diagram of the state at point IV. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1 Yu Fu Figure 7 The present invention will be described in detail with reference to specific embodiments.

[0023] This specific embodiment provides a hydraulic press with an ultra-high pressure and a large worktable. The hydraulic press includes a movable slider 1 and a lower worktable located below the slider 1, wherein the deflection compensation mechanism is integrally built into the body of the slider 1.

[0024] The bottom of the slider 1 has several downward-opening compensation chambers. Each compensation chamber has an independent compensation cylinder body 3 compactly installed inside. The cylinder body 3 has a plunger 4 for outputting downward thrust. A compensation moving plate 5 is installed in the compensation chamber and directly below the plunger 4. When the plunger 4 is driven downward by the oil circuit, it can directly act on the upper surface of the compensation moving plate 5.

[0025] To support and limit the compensation components and transmit bending moment, a stop is fixedly installed at the bottom of the slider 1. In this embodiment, the stop is specifically an upper pad 2, which covers the lower part of the compensation chamber and supports and limits the compensation moving plate 5 and the compensation cylinder body 3 upwards. The upper pad 2 is fixed to the bottom of the slider 1 by high-strength bolts. When the ultra-high pressure hydraulic medium is introduced into the compensation cylinder body 3 to drive the plunger 4 to press down against the compensation moving plate 5, the downward force of the plunger 4 is transmitted to the bottom of the slider 1 through the compensation moving plate 5, the upper pad 2 and the bolts in sequence, forming a downward pulling force at the bottom of the slider 1. This force then applies a reverse bending moment to the slider 1 to counteract its downward deflection under the compressive load, thus maintaining the high flatness of the slider 1.

[0026] An ultra-high pressure butt sealing structure is provided at the interface transition area between the slider 1 body and the compensating cylinder body 3. A stepped oil passage hole 101 is provided on the slider 1 body and communicates with the compensating cylinder body 3. A bridge sealing tube is inserted into the stepped oil passage hole 101, with one end extending into the oil inlet of the compensating cylinder body 3 and the other end extending into the oil passage hole 101 of the slider 1 body. A high-pressure resistant sealing element is fitted around the outer periphery of the bridge sealing tube. This high-pressure resistant sealing element includes an elastic sealing ring and a metal anti-extrusion retaining ring placed on the high-pressure side of the elastic sealing ring. When the high-pressure medium enters the oil passage, the high-pressure medium acts on the high-pressure resistant sealing element, causing it to expand axially, achieving a self-tightening seal at the interface between the slider 1 body and the compensating cylinder body 3. Simultaneously, the bridge sealing tube can adaptively absorb the relative micro-displacement between the slider 1 and the compensating cylinder body 3 when the slider 1 undergoes bending deformation under load, preventing interface shear damage.

[0027] The compensation chambers at the bottom of the slider 1 can be arranged in a matrix with multiple rows and columns, including a central chamber arranged along the length of the slider 1 and edge chambers located on both sides of the central chamber. Each compensation chamber in the matrix is ​​equipped with a corresponding compensation cylinder body 3, plunger 4, and compensation moving plate 5. The compensation cylinders in each compensation chamber are connected to a pressure control oil circuit for individually supplying and regulating the pressure of each compensation cylinder.

[0028] Due to the different spatial structures of the top and side of slider 1, the compensation cylinder located in the middle chamber is equipped with a connecting oil pipe passing through the top of slider 1; while the compensation cylinder located in the edge chamber is equipped with a lateral ultra-high pressure docking oil inlet assembly introduced from the side of slider 1.

[0029] The lateral ultra-high pressure docking oil inlet assembly is fixedly installed at the oil inlet channel on the side of the slider 1, specifically including a connecting seat 10 fixedly installed at the oil inlet channel and an oil pipe nozzle 20 inserted into the connecting seat 10.

[0030] One end of the connecting seat 10 forms a plug-in portion 11, which is fixedly plugged into the oil channel. As shown in the attached figure, the plug-in portion 11 has an external thread and a wall groove 112. The wall groove 112 has a retaining block 113. The inner wall of the oil inlet channel on the side of the slider 1 has an internal thread. The screw connection of the external thread and the internal thread achieves the axial fixation of the connecting seat 10. The wall groove 112 is fitted with a U-shaped buckle 13, which has a through hole 131. A threaded hole is formed on the side of the slider 1 corresponding to the through hole. After the bolt passes through the through hole, it is screwed into the threaded hole. The retaining block 113 rests on the opening 132 of the retaining block 13 and is fixed in the circumferential direction. Thus, the connecting seat 10 is fixed at the oil inlet channel.

[0031] The insertion part 11 has a first conical surface 111 inside, and the front end of the oil nozzle 20 has a second conical surface 201 on its outer periphery. The taper of the first conical surface 111 is set to be greater than the taper of the second conical surface 201. When the oil nozzle 20 and the connecting seat 10 are axially pressed together, due to the taper difference, the front end of the oil nozzle 20 and the first conical surface 111 form an annular linear sealing contact on the side closest to the high-pressure oil, leaving the gap for the outer low-pressure area, preventing high-pressure oil from wedging into the interface gap and pushing away the oil nozzle 20, thus greatly improving the ultra-high pressure sealing performance.

[0032] The connecting seat 10 is circumferentially hinged with several abutment rods 12. A torsion spring (not shown in the figure) can be mounted on the hinge axis of each abutment rod 12. One end of the torsion spring is connected to the connecting seat, and the other end abuts against the abutment rod 12, causing the long end 121 of the abutment rod 12 to tend to abut against the inner wall of the sleeve 31. The hinge center of the abutment rod 12 is offset from its geometric center, thus forming a long end 121 and a short end 122. A retaining ring 40 is fixedly mounted on the outer periphery of the oil nozzle 20, and the short end 122 of each abutment rod 12 movably abuts against the back of the retaining ring 40.

[0033] The lateral ultra-high pressure inlet assembly also includes a locking mechanism sleeved on the outside of the connector 10. Specifically, the locking mechanism includes a sleeve 31 movably sleeved on the outer periphery of the connector 10 and a locking nut 32 threadedly connected to the connector 10. A spring washer (not shown in the figure) is provided between the sleeve 31 and the locking nut 32. A pressure slope 311 is formed on the inner wall of the sleeve 31. During assembly and locking, rotating the locking nut 32 pushes the sleeve 31 axially through the spring washer. The pressure slope 311 on the inner wall of the sleeve 31 compresses the long ends 121 of each abutment rod 12, causing them to converge and tilt inwards. Based on the lever principle, the short ends 122 of the abutment rods 12 generate amplified axial thrust and push the abutment ring 40, driving the oil nozzle 20 to forcefully press inwards against the connector 10, ensuring the mechanical locking stability of the high-pressure connector.

[0034] The pressure control circuit includes a high-pressure oil supply main pipe and several independent branches, each connected to one of the compensation cylinders in the matrix. Each independent branch is equipped with an independent electro-hydraulic proportional pressure regulating valve or servo valve connected in series. Pressure sensors are installed on each compensation cylinder body or in its corresponding independent branch of the pressure control circuit to detect and provide feedback on the current pressure signal of the corresponding compensation cylinder in real time. The control system is electrically connected to the control terminals of each electro-hydraulic proportional pressure regulating valve or servo valve and the pressure sensors. Based on the feedback signals from the pressure sensors and the preset pressing process requirements, the control system independently adjusts the opening of each electro-hydraulic proportional pressure regulating valve or servo valve, enabling the compensation cylinders located in the central chamber and the side edge chambers to output asymmetrical or non-uniform compensation pressure, meeting customized compensation requirements under complex off-center load conditions.

[0035] The hydraulic press also includes a main cylinder pressure sensor for acquiring real-time pressure of the main cylinder, which is connected to the control system. The control system pre-stores a mapping matrix or proportional coefficient between the main cylinder pressure and the target pressure of each compensation cylinder. During pressing operation, the control system acquires the pressure signal from the main cylinder pressure sensor in real time and calculates the target set pressure of each compensation cylinder in the matrix at the current moment based on the mapping matrix or proportional coefficient. Then, it combines the real-time pressure feedback values ​​acquired by the pressure sensors of each compensation cylinder to perform PID closed-loop regulation, driving the pressure control oil circuit to adjust the output pressure, ultimately achieving dynamic and precise tracking of the output pressure of each compensation cylinder with the main cylinder pressure.

Claims

1. A hydraulic press, comprising a slide block, characterized in that, The bottom of the slider has several downward-opening compensation chambers, each containing a compensation cylinder body. A plunger slides within the compensation cylinder body, and a compensation moving plate is located within the compensation chamber and below the plunger. When the plunger extends downwards, it acts on the compensation moving plate. A stop is fixedly installed at the bottom of the slider, covering the compensation chambers to support and limit the upward movement of the compensation moving plate and the compensation cylinder body. Each compensation cylinder in each compensation chamber is connected to a pressure control oil circuit for individual pressure supply and adjustment. Each compensation cylinder or its corresponding pressure control oil circuit is equipped with a pressure sensor for real-time detection and feedback of the current pressure signal of the corresponding compensation cylinder. The control system adjusts the output pressure of each compensation cylinder individually based on the feedback signal from the pressure sensor and preset pressing process requirements. The plunger, driven by the high-pressure medium, presses downwards against the compensation moving plate, and through the stop, applies a reverse bending moment to the slider to counteract its downward deflection.

2. A hydraulic press according to claim 1, characterized in that, The stop is an upper pad, which is fixed to the bottom of the slider by bolts; the downward force of the plunger is transmitted to the bottom of the slider in sequence through the compensating moving plate, the upper pad and the bolts, forming a downward pulling force.

3. A hydraulic press according to claim 1, characterized in that, The slider body is provided with a stepped oil passage hole that communicates with the compensating cylinder body; a bridging sealing tube is embedded in the stepped oil passage hole, one end of which extends into the oil inlet of the compensating cylinder body, and the other end extends into the oil passage hole of the slider body; a high-pressure resistant sealing element is sleeved on the outer periphery of the bridging sealing tube, which includes an elastic sealing ring and a metal anti-extrusion retaining ring placed on the high-pressure side of the elastic sealing ring; when the high-pressure medium is introduced, the high-pressure medium acts on the high-pressure resistant sealing element to make it expand axially to achieve a self-tightening seal at the interface between the slider body and the compensating cylinder body.

4. A hydraulic press according to claim 1, characterized in that, The compensation chamber includes a central chamber arranged along the length of the slider and edge chambers located on both sides of the central chamber; the compensation cylinder placed in the central chamber is equipped with a connecting oil pipe passing through the top of the slider; the compensation cylinder placed in the edge chamber is equipped with a lateral ultra-high pressure docking oil inlet assembly introduced from the side of the slider, the lateral ultra-high pressure docking oil inlet assembly includes a connecting seat fixedly installed at the oil inlet channel on the side of the slider and an oil pipe nozzle inserted into the connecting seat.

5. A hydraulic press according to claim 4, characterized in that, One end of the connector forms a plug-in part, which is fixedly plugged into the oil channel. The plug-in part has an external thread and a wall groove. The wall groove has a locking block. The inner wall of the oil inlet channel on the side of the slider has an internal thread. The screw connection of the external thread and the internal thread fixes the connector in the axial direction. The wall groove is fitted with a U-shaped buckle with a through hole. The side of the slider has a threaded hole corresponding to the through hole. After the bolt passes through the through hole, it is screwed into the threaded hole. The locking block rests on the opening of the buckle and is fixed in the circumferential direction.

6. A hydraulic press according to claim 4, characterized in that, The connector has a first conical surface inside, and a second conical surface is formed on the outer periphery of the front end of the oil nozzle. The taper of the first conical surface is greater than that of the second conical surface, so that when the oil nozzle and the connector are axially pressed together, an annular linear sealing contact is formed on the side near the high-pressure oil. The connector has several abutment rods circumferentially hinged. The hinge center of the abutment rod is offset from the center of the abutment rod to form a long end and a short end. An abutment ring is fixed on the outer periphery of the oil nozzle, and the short end of each abutment rod is movably pressed against the abutment ring. The lateral ultra-high pressure docking oil inlet assembly also includes a locking mechanism sleeved on the outside of the connector. The locking mechanism is used to push the long end of each abutment rod to tilt and swing inward, so that the short end of the abutment rod pushes the abutment ring, thereby driving the oil nozzle to axially press against the connector.

7. A hydraulic press according to claim 6, characterized in that, The locking mechanism includes a sleeve that is movably fitted around the outer periphery of the connecting seat and a locking nut that is threadedly connected to the connecting seat; the inner wall of the sleeve is provided with a pressure slope, and when the locking nut is rotated and pushed forward, it pushes the sleeve to move axially, and the pressure slope squeezes the long ends of each abutment rod together.

8. A hydraulic press according to claim 1 or claim 5, characterized in that, The pressure control circuit includes a high-pressure oil supply main pipe and several independent branches that are connected to each of the aforementioned compensation cylinders. Each independent branch is equipped with an independent electro-hydraulic proportional pressure regulating valve or servo valve connected in series. The control system is electrically connected to the control terminal of each electro-hydraulic proportional pressure regulating valve or servo valve and is used to adjust the opening of each electro-hydraulic proportional pressure regulating valve or servo valve independently according to the feedback signal of each pressure sensor, so that each compensation cylinder outputs asymmetrical or non-uniform compensation pressure.

9. A hydraulic press according to claim 1, characterized in that, The compensation chambers are arranged in a matrix at the bottom of the slider, with each chamber equipped with a corresponding compensation cylinder body, plunger and compensation moving plate. Each compensation cylinder in the matrix is ​​independently controlled by the pressure control oil circuit.

10. A hydraulic press according to claim 1, characterized in that, The hydraulic press also includes a main cylinder pressure sensor for collecting real-time pressure of the main cylinder of the press. The main cylinder pressure sensor is connected to the control system signal. The control system has a preset mapping relationship matrix or proportional coefficient between the main cylinder pressure and the target pressure of each compensation cylinder. During the pressing process, the control system acquires the signal from the master cylinder pressure sensor in real time, and calculates the target set pressure of each compensation cylinder at the current moment based on the mapping relationship matrix or proportional coefficient. Then, it combines the real-time pressure feedback value collected by the pressure sensor on each compensation cylinder to perform PID closed-loop regulation, driving the pressure control oil circuit to adjust the output pressure, so as to realize the dynamic following of the pressure of each compensation cylinder with the pressure of the master cylinder.

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