Limiting device

Abstract

The invention discloses a limiting device, which belongs to the technical field of limiting devices of walking mechanisms of heavy forging and pressing equipment and comprises a hydraulic spring cylinder, a first rotating shaft and a mounting seat. One end of a piston rod of the hydraulic spring cylinder outside the cylinder is connected with a rack. The cart impacts the piston rod, the piston rod slides to drive the rack to linearly displace and drive the gear to rotate, so that the first rotating shaft and the movable block loaded on the first rotating shaft are driven to rotate, the first sliding block and the second sliding block are pushed to be away from each other, the first spring and the second spring on the back faces of the two sliding blocks are elastically deformed and shortened, and kinetic energy is converted into elastic potential energy to be stored. The hydraulic spring cylinder partially converts the kinetic energy of the cart into hydraulic oil heat energy for dissipation, and partially converts the kinetic energy into elastic potential energy of a third spring for storage. When the cart needs to leave the position, the springs can release elastic potential energy to assist the cart to walk. Compared with the prior art, permanent damage of instant huge impact force to a limited vehicle body structure can be reduced.

Description

Technical Field

[0001] This invention relates to the technical field of limiting devices for the traveling mechanism of heavy forging equipment, and more specifically, to a limiting device. Background Technology

[0002] The forging manipulator is a key piece of equipment in the forging production line, and the precise positioning and reliable limiting of its trolley traveling mechanism directly affect production safety and efficiency. Currently, the limiting devices mainly used in the industry are typically mechanical hard limiters, which use rigid blocks at the end of the trolley's track, relying on the block's firm anchoring to the ground and its own rigidity to limit movement. This type of limiting device simply absorbs energy through the crushing of the rigid block to stop the machine. While simple in structure, it has significant drawbacks: forces are reciprocal. When the manipulator impacts the block at high speed, it generates a huge instantaneous impact force. This impact not only causes the rigid block to crush but also causes permanent damage to the limited trolley structure and track foundation. Long-term use can easily lead to structural fatigue and shorten the service life of the trolley structure.

[0003] Therefore, how to provide a new limiting device to reduce the permanent damage to the limited vehicle structure caused by instantaneous huge impact force has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] The purpose of this invention is to provide a limiting device to solve the aforementioned technical problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A limiting device, characterized in that it comprises: Hydraulic spring cylinder, first rotating shaft and mounting base; The piston rod of the hydraulic spring cylinder has a sliding section and a buffer section at the end outside the cylinder. The buffer section is located at the end of the piston rod away from the piston. The buffer section is connected to a rack, which extends from the buffer section of the piston rod in the same direction as the sliding direction of the piston rod. The mounting base is stationary in a confined environment. The mounting base has a first track, within which a first slider and a second slider are slidably connected, both sliding along a first straight line. A mounting cavity is located in the middle of the first track along the first straight line, and a bearing seat is provided within the mounting cavity. One axial end of a first rotating shaft is located within the first track and connected to a movable block; the other end passes through the bearing seat and exits the first track. The axial direction of the first rotating shaft is perpendicular to the first straight line. The movable block is elongated and rotates freely 360° within the mounting cavity. The axis of the first rotating shaft passes through the middle of the movable block's length along the first straight line. The first slider, movable block, and second slider are arranged sequentially opposite each other. The first slider is connected to the mounting base via a first spring on the side away from the movable block, and the second slider is connected to the mounting base via a second spring on the side away from the movable block. The extension and retraction directions of the first and second springs are consistent with the first linear direction. When both are in the first natural extension and retraction state, there is a preset gap between the first slider and the movable block, and they are located within the area enclosed by the rotation trajectories of the two ends of the movable block. A gear is coaxially connected to one end of the first rotating shaft that extends out of the first track. The gear meshes with the rack for transmission. The piston rod slides, causing the rack to move linearly. The gear rotates accordingly, thereby causing the first rotating shaft and its movable block to rotate, pushing the first slider and the second slider away from each other / closer.

[0006] Optionally, the hydraulic spring cylinder has an outer cylinder, inside which an inner cylinder is fixedly installed. A preset gap is provided between the inner and outer cylinder walls to form a sandwich space. The inner and outer cylinders are coaxial and their openings face the same side. One end of the inner cylinder's opening is sealed with a mounting block. Hydraulic oil is added to the inside of the inner cylinder. Along the radial direction of the inner cylinder, the outer wall of the mounting block protrudes from the outer wall of the inner cylinder and is sealed to the inner wall of the outer cylinder at its opening end. A piston is slidably connected inside the inner cylinder, sliding axially along the inner cylinder. The side of the piston away from the inner cylinder's opening is connected to the bottom of the inner cylinder via a third spring. The spring's extension and contraction direction is consistent with the inner cylinder's axial direction. A piston rod is connected to the side of the piston facing the inner cylinder's opening. The other end of the piston rod passes through the mounting block and the outer cylinder. The end of the piston rod that passes through has a sliding section and a buffer section distributed along the length of the piston rod. The buffer section is located at the end of the piston rod away from its piston. Several damping holes are opened on the radial sidewall of the inner cylinder. An oil return hole is opened at the axial end of the inner tube's opening. The piston has an oil return channel, which is used to connect the oil return hole and the rodless chamber of the inner cylinder when the piston slides to the correct position. A first valve is installed in the oil return channel.

[0007] Optionally, a bearing is provided between the outer wall of the mounting block and the inner wall of the outer cylinder. The mounting block is rotatably connected to the inner wall of the outer cylinder via the bearing. Along the radial direction of the inner cylinder, an annular notch is provided on the outer wall of the piston facing the piston rod. One axial end of the annular notch helps to enclose the rod-side cavity of the inner cylinder. The radially outer side of the annular notch communicates with the oil return hole. The piston has a first channel, through which the annular notch communicates with the rodless cavity of the inner cylinder. The oil return channel includes the annular notch and the first channel, and a first valve is installed in the first channel.

[0008] Optionally, the mounting block is provided with a first annular groove, the first annular groove is filled with a pressure-accumulating sponge, and the mounting block is also provided with a first perforation to connect the interlayer space between the inner and outer cylinders and the first groove.

[0009] Optionally, a second sealing portion is provided between the outer wall of the piston rod and the inner wall of the mounting block.

[0010] Optionally, the second sealing part is an oil seal.

[0011] Optionally, a dustproof ring is provided between the inner wall of the outer cylinder opening and the outer wall of the piston rod.

[0012] Optionally, it also includes a base; The base is equipped with a lead screw type linear displacement device. The driven part of the lead screw type linear displacement device is connected to the hydraulic spring cylinder. The linear displacement direction of the driven part is consistent with the sliding direction of the piston rod.

[0013] The limiting device provided by this invention is equipped with a hydraulic spring cylinder. When the vehicle body structure moves close to the limiting device, it impacts the piston rod of the hydraulic spring cylinder at the end outside the cylinder. The piston slides and compresses the spring, causing it to shorten due to elastic deformation. Hydraulic oil flows out from the damping orifice into the interlayer space, thereby converting the kinetic energy of the vehicle body structure into the thermal energy of the hydraulic oil in the hydraulic spring cylinder and the elastic potential energy of its spring, thus buffering and absorbing energy. Existing technology only utilizes the material crushing and high-frequency vibration (noise) of rigid blocks to absorb energy. The micro-elastic deformation of the material cannot provide sufficient buffering time, and the impact force acts for an extremely short time, almost instantaneously completing contact and interception. Under a certain momentum, the magnitude of the impact force is inversely proportional to the acting time, which leads to extremely large instantaneous peak impact forces on the block itself and the vehicle body structure, causing structural damage to both. The spring of this invention has a stronger elastic deformation capacity than the rigid block, and when the piston rod is compressed, the hydraulic oil must be discharged through the damping orifice and the return oil orifice. This process forces the kinetic energy of the impact to be converted into the viscous dissipation (heat energy) of the hydraulic oil, which prolongs the impact time and reduces the peak impact force. As a result, there is less noise and less structural damage to the limiting device itself and the vehicle body structure it limits, thus extending the service life of both.

[0014] Building upon this foundation, this application further adds a sliding section and a buffer section to the piston rod. The sliding section allows the piston rod to slide into the cylinder and participate in the aforementioned nonlinear damping-elastic buffering process. The buffer section enhances the energy absorption capacity of the limiting device. The buffer section is equipped with a rack that moves linearly in sync with the piston rod, driving the meshing gears to rotate, thereby driving the first rotating shaft to rotate. When no external force is applied, the first and second springs are in a natural extension / retraction state, the first and second sliders are closest to each other, and the length direction of the movable block of the first rotating shaft is exactly perpendicular to the first linear direction. The two sides of the movable block's width face the first and second sliders, without contact or with either of them, or the contact surfaces do not exert any force on them. When the vehicle structure moves close to the limiting device, it impacts the end of the piston rod outside the cylinder. The piston causes the piston rod to slide, driving the gears to rotate, which in turn drives the first rotating shaft and the movable block to rotate. The two ends of the movable block's length respectively contact the first and second sliders. The vehicle body structure continues to impact the piston rod, causing the piston and piston rod to slide continuously. The movable block continues to rotate, compressing the first and second sliders. Before the rotation angle reaches 90°, the length of the rotating movable block along the first straight line increases at both ends, pushing the first and second sliders away from each other. The first and second springs shorten due to compressive elastic deformation. When the piston rod slides to the limit of its allowable range of motion (when the return oil hole of the hydraulic spring cylinder and the return oil channel of the piston are aligned and connected), the length direction of the movable block is aligned with the first straight line. This invention also converts the impact kinetic energy into the elastic potential energy of the first and second springs for energy absorption and buffering. Compared with the prior art, this application can prolong the impact time, reduce the peak impact force, reduce noise, and cause less structural damage to the limiting device itself and the vehicle body structure it limits, thus extending their service life. Attached Figure Description The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings: Figure 1 This is a partial structural schematic diagram of a limiting device provided in an embodiment of this application; Figure 2 for Figure 1 Side view of the embodiment; Figure 3 This is a schematic diagram of the structure of a spring hydraulic cylinder provided in one embodiment of this application; Figure 4 for Figure 3 A magnified view of a portion of the image; Figure 5 for Figure 1A partial structural schematic diagram of the mounting base in the embodiment.

[0015] Reference numerals: 100, outer cylinder; 200, inner cylinder; 210, damping hole; 220, oil return hole; 230, third spring; 240, mounting block; 241, first annular groove; 242, pressure accumulator sponge; 243, first perforation; 244, bearing; 250, oil seal; 260, dust seal; 270, pressure sensor; 310, piston; 311, annular notch; 312, first channel; 313, first valve; 320, piston rod; 321, rack; 330, connecting part; 331, first section; 332. Second segment; 333, Third segment; 334, Impact head; 410, Gear; 420, First rotating shaft; 430, Moving block; 500, Mounting base; 510, First track; 511, First spring; 512, First slider; 513, Guide post; 514, Second slider; 515, Second spring; 600, Base; 610, Driving element; 620, Track of the lead screw linear displacement device; 630, Bearing seat of the lead screw linear displacement device; 640, Driven element; 650, Drive device of the lead screw linear displacement device. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0017] See Figures 1 to 5 As shown, the present invention provides a limiting device, including a hydraulic spring cylinder, a first rotating shaft 420 and a mounting base 500.

[0018] The piston rod 320 of the hydraulic spring cylinder has a sliding section and a buffer section at one end outside the cylinder. The buffer section is located at the end of the piston rod 320 away from its piston 310. The buffer section is connected to a rack 321, which extends from the buffer section of the piston rod 320 and extends in the same direction as the sliding direction of the piston rod 320. The mounting base 500 is stationary in a limited environment. The mounting base 500 is provided with a first track 510. A first slider 512 and a second slider 514 are slidably connected within the first track 510, both sliding along a first straight line direction. A mounting cavity is provided in the middle of the first track 510 along the first straight line direction. A bearing 244 seat is provided in the mounting cavity of the first track 510. One axial end of a first rotating shaft 420 is located within the first track 510 and connected to a movable block 430. The other end passes through the bearing 244 seat and exits the first track 510. The axial direction of the first rotating shaft 420 is perpendicular to the first straight line direction. The movable block 430 is elongated and can rotate freely 360° within the mounting cavity. The axis of the first rotating shaft 420 passes through the middle of the movable block 430 along its length direction. The first slider 512, movable block 430, and second slider 514 are sequentially arranged opposite each other along the first straight line direction. Block 512 is connected to the mounting base 500 on the side away from the movable block 430 via the first spring 511. The second slider 514 is connected to the mounting base 500 on the side away from the movable block 430 via the second spring 515. The extension and retraction directions of the first and second springs 515 are consistent with the first linear direction. When they are in the first natural extension and retraction state, there is a preset gap between the first slider 512 and the second slider 514 and the movable block 430, and they are located within the area enclosed by the rotation trajectory of both ends of the movable block 430. The first rotating shaft 420 is coaxially connected to a gear 410 at one end that extends out of the first track 510. The gear 410 meshes with the rack 321 for transmission. The piston rod 320 slides, causing the rack 321 to move linearly. The gear 410 rotates accordingly, thereby causing the first rotating shaft 420 and its movable block 430 to rotate, pushing the first slider 512 and the second slider 514 away from each other / closer.

[0019] The limiting device provided by this invention is equipped with a hydraulic spring cylinder. When the vehicle body structure moves close to the limiting device, it impacts the piston rod 320 of the hydraulic spring cylinder at the end outside the cylinder. The piston 310 slides and compresses the spring, causing its elastic deformation to shorten. Hydraulic oil flows out from the damping hole 210 into the interlayer space, thereby converting the kinetic energy of the vehicle body structure into the thermal energy of the hydraulic oil in the hydraulic spring cylinder and the elastic potential energy of its spring, thus buffering and absorbing energy. Existing technology only utilizes the material crushing and high-frequency vibration (noise) of rigid blocks to absorb energy. The micro-elastic deformation of the material cannot provide sufficient buffering time, and the impact force acts for an extremely short time, almost instantaneously completing contact and interception. Under a certain momentum, the magnitude of the impact force is inversely proportional to the acting time, which leads to extremely large instantaneous peak impact forces on the block itself and the vehicle body structure, causing structural damage to both. The spring of this invention has a stronger elastic deformation capacity than the rigid block, and when the piston rod 320 is compressed, the hydraulic oil must pass through the damping hole 210 and the return oil hole 220 to be discharged. This process forces the kinetic energy of the impact to be converted into the viscous dissipation (heat energy) of the hydraulic oil, which prolongs the impact time and reduces the peak impact force. As a result, there is less noise and less structural damage to the limiting device itself and the vehicle body structure it limits, thus extending the service life of both.

[0020] Building upon this foundation, this application further adds a sliding section and a buffer section to the piston rod 320. The sliding section allows the piston rod 320 to slide into the cylinder body and participate in the aforementioned nonlinear damping-elastic buffering process. The buffer section enhances the energy absorption capacity of the limiting device. The buffer section is equipped with a rack 321, which moves linearly synchronously with the piston rod 320, driving the meshing gear 410 to rotate, thereby driving the first rotating shaft 420 to rotate. When no external force is applied, the first spring 511 and the second spring 515 are in a naturally extended / retracted state. The first slider 512 and the second slider 514 are closest to each other. The length direction of the movable block 430 of the first rotating shaft 420 is exactly perpendicular to the first linear direction. The two sides of the width of the movable block 430 face the first and second sliders 514, and there is no contact between it and the first slider 512 or the second slider 514, or the contact surface does not exert any force on them. As the vehicle structure approaches the limiting device, it impacts the piston rod 320 at one end outside the cylinder. The piston 310 causes the piston rod 320 to slide, driving the gear 410 to rotate, which in turn rotates the first rotating shaft 420 and the movable block 430. The two ends of the movable block 430 contact the first slider 512 and the second slider 514, respectively. The vehicle structure continues to impact the piston rod 320, and the piston 310 and piston rod 320 continue to slide. The movable block 430 continues to rotate, pressing against the first slider 512 and the second slider 514. Before the rotation angle reaches 90°, the length of the two ends of the rotating movable block 430 along the first straight line continuously increases, pushing the first slider 512 and the second slider 514 away from each other. The first spring 511 and the second spring 515 shorten due to elastic deformation under pressure. When the oil return hole 220 and the oil return channel of the piston rod 320 are aligned and connected, the length direction of the movable block 430 is consistent with the first straight line direction. The present invention also converts the impact kinetic energy into the elastic potential energy of the first spring 511 and the second spring 515 for energy absorption and buffering. Compared with the prior art, the present application can prolong the impact time, reduce the peak impact force, reduce noise, and cause less structural damage to the limiting device itself and the vehicle body structure limited by it, thus extending the service life of both.

[0021] A guide post 513 is provided on the side of the first slider 512 opposite to the second slider 514, located within the helical structure of the first spring 511. The cylindrical axis of the guide post 513 is aligned with the first straight line direction. A guide post 513 is also provided on the side of the second slider 514 opposite to the first slider 512, located within the helical structure of the second spring 515. The cylindrical axis of the guide post 513 is aligned with the first straight line direction. Optionally, the guide post 513 may be shorter, or the first track 510 may have reserved space for it, or the first track 510 may have a second through hole to allow the guide post 513 to pass through the first track 510 along the first straight line direction. Figure 5 As shown.

[0022] In one possible implementation, the hydraulic spring cylinder has an outer cylinder 100, and an inner cylinder 200 is fixedly installed inside the outer cylinder 100. A preset gap is provided between the wall of the outer cylinder 100 and the wall of the inner cylinder 200. The inner and outer cylinders 100 are coaxial and their openings face the same side. A mounting block 240 is rotatably connected to one end of the opening of the inner cylinder 200. Hydraulic oil is added to the inside of the inner cylinder 200. The outer wall of the mounting block 240 protrudes from the outer wall of the inner cylinder 200 along the radial direction of the inner cylinder 200. A first sealing part is provided annularly between the outer wall of the mounting block 240 and the inner wall of the outer cylinder 100. A piston 310 is slidably connected to the inner wall of the inner cylinder 200 and slides axially within the inner cylinder 200. The side of the piston 310 away from the opening of the inner cylinder 200 is connected to the inner cylinder 200 by a third spring 230. At the bottom of the cylinder, the extension and retraction direction of the third spring 230 is consistent with the axial direction of the inner cylinder 200. The piston 310 is connected to the piston rod 320 on the side facing the opening of the inner cylinder 200. The other end of the piston rod 320 passes through the mounting block 240 and the outer cylinder 100. Along the length of the piston rod 320, the end of the piston rod 320 that passes through the outer cylinder 100 is provided with a sliding section and a buffer section in sequence. The buffer section is located at the end of the piston rod 320 away from the piston 310. Several damping holes 210 are opened on the radial side wall of the inner cylinder 200. The inner tube has an oil return hole 220 at the axial end of the opening. An oil return channel is provided on the side wall of the piston 310 near the piston rod 320. The oil return channel is used to connect the oil return hole 220 and the rodless cavity of the inner cylinder 200. The oil return channel is equipped with a first valve 313, which is used to switch the on / off state of the oil return channel.

[0023] When the trolley approaches the limit device and impacts the impact head 334, the first valve 313 should be closed, the return oil passage is cut off, and the hydraulic oil enters the rod chamber from the return oil hole 220. It cannot return to the rodless chamber from the return oil passage. The piston 310 and piston rod 320 slide back into the inner cylinder 200 to squeeze the hydraulic oil in the rodless chamber, converting kinetic energy into hydraulic oil heat energy, until the trolley's kinetic energy is completely converted, stored / released, causing the trolley to stop moving.

[0024] The forging manipulator under the load of the trolley performs forging operations at this set position. During the operation, the first valve 313 remains closed, preventing the hydraulic oil from flowing back to the rodless chamber via the return channel. The flow resistance of the hydraulic oil in the rod chamber flowing back to the rodless chamber through the return port 220 and damping port 210 is extremely high. The elastic potential energy stored in the spring is less than the initial kinetic energy of the trolley (partially converted into hydraulic oil heat dissipation), which is insufficient to drive the hydraulic oil to flow back along the original path. Therefore, the limit device and the trolley remain stationary.

[0025] After the forging operation is completed, the trolley needs to leave the designated position (to proceed to the next forging station or to end the work). At this time, the first valve 313 is opened. The hydraulic oil in the rod chamber flows back through the return channel with minimal resistance and minimal heat dissipation. The elastic potential energy stored in each spring is converted into kinetic energy as the springs extend and return to their natural extension state. The rodless chamber draws in oil under negative pressure, and the hydraulic oil flows back through the return channel. The third spring 230 pushes the piston 310 to slide in the opposite direction. The first and second springs 515 push the movable block 430 to rotate in the opposite direction. The gear 410 rotates synchronously in the opposite direction, pushing the rack 321 and piston rod 320 to slide in the opposite direction. The piston rod 320 gradually extends out of the cylinder, assisting the trolley to move in the opposite direction. When the piston rod 320 reaches its peak extension length, the trolley continues to move, and the trolley structure separates from the impact head 334. The entire limiting device returns to its initial state, ready to welcome the next work cycle.

[0026] This application does not specifically limit the switching method of the opening and closing state of the first valve 313, as long as it can complete the specified action when needed to realize the on / off control of the return channel. Optionally, the first valve 313 is a solenoid valve, and the limit device is equipped with a controller, which controls the opening and closing of the first valve 313. The controller can be manually operated to switch the opening and closing state of the first valve 313, or the controller can control it automatically. For example, in the initial state of the limit device, each spring is in a natural extension and contraction state, and the first valve 313 is in the closed state. The controller is electrically connected to the main controller of the trolley / forging press manipulator. The limit device limits and stops the forging press manipulator at a set position. When the forging press manipulator completes the forging operation at the set position, and the trolley is about to drive the forging press manipulator loaded with it away from the set position, it sends a "departure" electrical signal to the controller of the limit device. Upon receiving the signal, the controller of the limit device sends a control command to the first valve 313, and the first valve 313 is opened under control. When the pressure sensor 270 detects that the oil pressure in the rodless chamber has stabilized and is no longer changing, the controller sends a control command to the first valve 313, restoring it to the closed state. Alternatively, without a controller, the pressure sensor 270 can report the measured oil pressure through its own display component, allowing personnel to learn through other means that the trolley and its loaded forging press are about to move away from the set position of the limit device. The first valve 313 is then manually opened, and after the trolley has moved away, the oil pressure is observed. Once the oil pressure stabilizes, the first valve 313 is manually closed again.

[0027] In one possible implementation, a bearing 244 is provided between the outer wall of the mounting block 240 and the inner wall of the outer cylinder 100. The mounting block 240 is rotatably connected to the inner wall of the outer cylinder 100 via the bearing 244. Along the radial direction of the inner cylinder 200, the piston 310 has an annular notch 311 on its outer wall facing the piston rod 320. One axial end of the annular notch 311 helps to enclose the rod cavity of the inner cylinder 300, and the radially outer side of the annular notch communicates with the oil return hole 220. The piston 310 has a first channel 312, through which the annular notch 311 communicates with the rodless cavity of the inner cylinder 200. The aforementioned oil return channel includes the annular notch 311 and the first channel 312, and a first valve is installed in the first channel. Optionally, the first channel 312 includes a second channel extending axially from the piston 310. One end of the second channel faces the bottom of the inner cylinder 200 and communicates with the rodless cavity, while the other end communicates with the notch area of ​​the annular notch 311 via a radially extending third channel.

[0028] In one possible implementation, the mounting block 240 is provided with a first annular groove 241, the first annular groove 241 is filled with a pressure-accumulating sponge 242, and the mounting block 240 is also provided with a first perforation 243 to connect the interlayer space between the inner and outer cylinders 100 and the first groove.

[0029] In one possible implementation, a second sealing portion is provided between the outer wall of the piston rod 320 and the inner wall of the mounting block 240. The second sealing portion is an oil seal 250. A dustproof ring 260 is provided between the inner wall of the outer cylinder 100 and the outer wall of the piston rod 320.

[0030] In one possible implementation, the piston rod 320 is connected to a strike head 334 at the end opposite to its piston 310. The strike head 334 includes a connecting part 330 and a buffer head. The connecting part 330 is provided with a first section 331, a second section 332, and a third section 333 in sequence. All three are cylindrical sections coaxial with the piston rod 320. The radius of the first section 331 is greater than the radius of the third section 333, which is greater than the radius of the second section 332. The first section 331 and the third section 333 form a second annular groove at the second section 332. The end of the first section 331 of the connecting part 330 opposite to the third section 333 is connected to the piston rod 320. The buffer head is provided with a connecting cavity with one open end. The connecting cavity is provided with a first annular protrusion and a third annular groove. The first annular protrusion matches and fits into the second annular groove. The third section 333 of the connecting part 330 matches and fits into the third annular groove. The connecting part 330 is connected to the buffer head.

[0031] In one possible implementation, the limiting device further includes a base 600; the base 600 is equipped with a lead screw-type linear displacement device, whose driven member is connected to a hydraulic spring cylinder, and the linear displacement direction of the driven member is consistent with the sliding direction of the piston rod 320. As is known, the base 600 of the lead screw-type linear displacement device should be equipped with a track 620 to guide the linear displacement of the driven member and restrict the rotation of the driven member. The driving member 610 of the lead screw-type linear displacement device is a lead screw, and its base 600 should also be equipped with a bearing 244 seat 630, through which the lead screw 640 is rotatably connected to the base 600, and can rotate freely on the base 600.

[0032] Preferably, such as Figure 2 As shown, the piston rod 320 passes through the driven member, and the piston rod 320 and the driven member are slidably connected. The sliding direction is the same as the sliding direction of the piston 310, thus providing both stable connection and support, and allowing the piston 310 and piston rod 320 to slide. Optionally, the driving member 610 can be equipped with a handwheel for manual adjustment of the hydraulic spring cylinder position. Alternatively, the driving member 610 can be equipped with a drive device 650 such as a servo motor, which powers the rotation of the driving member 610. Optionally, both the base 600 and the mounting base 500 are fixed to the ground for stable anchoring.

[0033] In one possible implementation, the hydraulic spring cylinder is further equipped with a pressure sensor 270 for monitoring and feeding back the oil pressure in the rodless chamber of the hydraulic spring cylinder. Optionally, the limit device also includes a controller, to which the pressure sensor 270 feeds back the measured oil pressure data. The controller can generate an alarm signal based on the obtained oil pressure data, controlling an alarm element to issue an alarm signal to alert personnel of an abnormal situation. The alarm element can be a buzzer, a speaker, or an indicator light.

[0034] Existing limit switches installed on limit devices are typically mechanically actuated switches. When the trolley's traveling mechanism collides with the limit stop, the limit switch mechanically activates, triggering an electrical signal that cuts off the power to the vehicle's traveling motor, thus stopping the vehicle. However, in actual operation, the mechanical contacts and transmission mechanism of the limit switch are easily damaged or displaced due to frequent impacts, resulting in a short lifespan and frequent signal failures. Furthermore, its triggering accuracy is significantly affected by factors such as the traveling speed of the manipulator and the load inertia, leading to positioning deviations and insufficient reliability. The controller of this invention can also generate control signals based on obtained hydraulic pressure data to control the movement of the vehicle structure, enabling the limit device to simultaneously perform both limit and limit switch functions. The controller of this invention constructs an intelligent closed-loop control system of "perception-decision-execution." Its control method is as follows: In the initial state, the limiting device has moved and locked at the preset limiting coordinates via the lead screw linear displacement device. At this time, the servo motor of the lead screw linear displacement device is de-energized and the brake is locked, preventing the lead screw from rotating. The first valve 313 is closed, and the oil return channel is blocked, preventing connection between the rod chamber and the rodless chamber. The first spring 511, the second spring 515, and the third spring 230 are in their natural extension and contraction state, and the piston rod 320 is in the extended position, at which point the extension length of the piston rod 320 is at its peak. Along the sliding direction of the piston rod 320, the impact head 334 of the piston rod 320 protrudes from the limiting device, facing the trolley. The oil pressure value monitored by the pressure sensor 270 is the initial system pressure P0.

[0035] When the forging press trolley travels along the track to the limit device, the impact head 334 on the piston rod 320 first collides with the car body structure, forcing the piston rod 320 to retract into the cylinder. The impact force is transmitted through the piston rod 320, compressing the first spring 511, the second spring 515, and the third spring 230, squeezing the hydraulic oil and forcing it to flow out through the damping hole 210 to the interlayer, generating a huge damping force proportional to the square of the piston 310's movement speed. This converts the main kinetic energy of the car body structure into heat energy and dissipates it, thereby achieving smooth deceleration.

[0036] During this buffering process, a high-precision pressure sensor 270 installed on the oil circuit of the spring hydraulic cylinder continuously and in real time monitors the oil pressure changes in the rodless chamber and transmits the pressure signal P to the controller in real time. The controller has two key pressure thresholds preset: a primary threshold P2 and a secondary threshold P2, where P2 > P1.

[0037] The controller compares the real-time measured oil pressure P in the rodless chamber with two threshold values. When the real-time pressure P ≥ P1, it indicates that the vehicle structure has fully entered the buffer stroke and the speed has significantly decreased, at which point a normal deceleration decision is made. The controller immediately sends a "deceleration complete" electrical signal to the vehicle's main controller. Upon receiving this signal, the main controller of the vehicle immediately cuts off the power to the vehicle structure's travel motor. Afterward, the manipulator relies entirely on the buffering effect of the limit device to smoothly stop until it comes to a complete stop.

[0038] If a malfunction causes the vehicle structure to fail to decelerate effectively, the oil pressure will continue to rise. When the controller determines that the real-time pressure P ≥ P2, it indicates that the buffer travel of the limit device is approaching its limit, posing a collision risk. The controller will immediately trigger the highest-level "emergency stop and alarm" electrical signal. The controller sends an electrical signal to the main controller of the trolley indicating that the buffer capacity of the limit device is about to be exceeded. Upon receiving this signal, the main controller of the trolley immediately cuts off the vehicle structure's driving power and takes other remedial measures to enable the trolley to decelerate autonomously, forcing the trolley to stop. At the same time, the controller sends an alarm electrical signal to the alarm element, triggering the alarm signal to warn the operator, thus forming a reliable safety redundancy.

[0039] When the forging process is completed and the trolley needs to reverse and leave, the first valve 313 is opened. Hydraulic oil in the rod chamber can flow back to the rodless chamber through the low-resistance return channel, instead of flowing back through the high-resistance damping orifice 210. The first, second, and third springs 230 release their stored elastic potential energy, sufficient to drive the rodless chamber to draw in oil under negative pressure, pushing the piston 310 to slide in the reverse direction. The piston rod 320 gradually extends out of the cylinder, assisting the trolley in reversing. When the piston rod 320 reaches its peak extension length, the trolley continues to move, and the vehicle structure separates from the impact head 334. The entire limiting device returns to its initial state, ready for the next work cycle.

[0040] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A limiting device, characterized in that, include: Hydraulic spring cylinder, first rotating shaft and mounting base; The piston rod of the hydraulic spring cylinder has a sliding section and a buffer section at one end outside the cylinder. The buffer section is located at the end of the piston rod away from the piston. The buffer section is connected to a rack, which extends from the buffer section of the piston rod in the same direction as the sliding direction of the piston rod. The mounting base is stationary in a confined environment. The mounting base has a first track, within which a first slider and a second slider are slidably connected, both sliding along a first straight line. A mounting cavity is located at the center of the first track along the first straight line, and a bearing seat is provided within the mounting cavity. One axial end of the first rotating shaft is located within the first track and connected to a movable block; the other end passes through the bearing seat and exits the first track. The axial direction of the first rotating shaft is perpendicular to the first straight line. The movable block is elongated and rotates freely 360° within the mounting cavity. The axis of the first rotating shaft passes through the center of the movable block along its length, along the first straight line. The first slider, movable block, and second slider are sequentially connected... In a relatively balanced configuration, the side of the first slider facing away from the movable block is connected to the mounting base via a first spring, and the side of the second slider facing away from the movable block is connected to the mounting base via a second spring. The extension and retraction directions of the first and second springs are consistent with the first linear direction. When both are in the first natural extension and retraction state, there is a preset gap between the first slider and the second slider and the movable block, and they are located within the area enclosed by the rotation trajectories of the two ends of the movable block's length. One end of the first rotating shaft that extends out of the first track is coaxially connected to a gear. The gear meshes with the rack for transmission. The piston rod slides, causing the rack to move linearly, and the gear rotates accordingly, thereby causing the first rotating shaft and its movable block to rotate, pushing the first slider and the second slider away from each other / closer.

2. The limiting device according to claim 1, characterized in that, The hydraulic spring cylinder has an outer cylinder, inside which an inner cylinder is fixedly installed. A preset gap is provided between the inner and outer cylinder walls to form a sandwich space. The inner and outer cylinders are coaxial and their openings face the same side. A mounting block is sealed to one end of the inner cylinder's opening. Hydraulic oil is added to the inside of the inner cylinder. Along the radial direction of the inner cylinder, the outer wall of the mounting block protrudes from the outer wall of the inner cylinder and is sealed to the inner wall of the outer cylinder at its opening end. A piston is slidably connected inside the inner cylinder, sliding axially along the inner cylinder. The side of the piston away from the inner cylinder's opening is connected to the bottom of the inner cylinder via a third spring. The extension and retraction direction of the third spring is consistent with the axial direction of the inner cylinder. The piston is connected to a piston rod on the side facing the inner cylinder opening. The other end of the piston rod passes through the mounting block and the outer cylinder. The end of the piston rod that passes through is provided with a sliding section and a buffer section distributed along the length of the piston rod. The buffer section is located at the end of the piston rod away from its piston. Several damping holes are opened on the radial sidewall of the inner cylinder. The inner tube has an oil return hole opened at the axial end of the cylinder opening. The piston is provided with an oil return channel for connecting the oil return hole and the rodless cavity of the inner cylinder when the piston slides to the position. The oil return channel is equipped with a first valve.

3. The limiting device according to claim 2, characterized in that, A bearing is provided between the outer wall of the mounting block and the inner wall of the outer cylinder. The mounting block is rotatably connected to the inner wall of the outer cylinder through the bearing. Along the radial direction of the inner cylinder, the piston has an annular notch on the outer wall facing the piston rod. One axial end of the annular notch helps to enclose the rod cavity of the inner cylinder. The radial outer side of the annular notch is used to communicate with the oil return hole. The piston has a first channel. The annular notch communicates with the rodless cavity of the inner cylinder through the first channel. The oil return channel includes the annular notch and the first channel. A first valve is installed in the first channel.

4. The limiting device according to claim 2, characterized in that, The mounting block is provided with a first annular groove, which is filled with a pressure-accumulating sponge. The mounting block is also provided with a first perforation to connect the interlayer space between the inner and outer cylinders and the first groove.

5. The limiting device according to claim 2, characterized in that, A second sealing portion is provided between the outer wall of the piston rod and the inner wall of the mounting block.

6. The limiting device according to claim 5, characterized in that, The second sealing part is an oil seal.

7. The limiting device according to claim 2, characterized in that, A dustproof ring is provided between the inner wall of the outer cylinder opening and the outer wall of the piston rod.

8. The limiting device according to claim 1, characterized in that, It also includes the base; The base is equipped with a lead screw linear displacement device, the driven part of which is connected to a hydraulic spring cylinder, and the linear displacement direction of the driven part is consistent with the sliding direction of the piston rod.

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