Automatically controlled crank gantry press and control method thereof

Abstract

The present invention discloses an automatic control crank gantry press and a control method thereof, which mainly relate to the field of hydraulic presses. It comprises a gantry frame arranged on the ground, a clamping mechanism symmetrically arranged on the gantry frame, a cushion block, a trolley, and a plurality of trolley positioning mechanisms arranged below the frame; the trolley carries a bicycle frame, the trolley positioning mechanism limits the trolley, the cushion block cooperates with the mounting hole of the bicycle crank, the clamping mechanism on the gantry frame presses the trolley in the center, and the cushion block is used to increase the contact area between the crank and the clamping mechanism. The beneficial effects of the present invention are: the device is used in the process of assembling the bicycle crank and the middle shaft, the assembly accuracy is high, the assembly process is safer, the manual operation is greatly reduced, the originally uneven crank surface is increased by the cushion block to increase its force range, so that the force is more uniform and the assembly effect is better, and it can be pressed along the middle shaft direction during the clamping process.

Description

Technical Field

[0001] The invention relates to the field of hydraulic presses, in particular to an automatic control crank gantry press and a control method thereof. Background Art

[0002] There are many types of bicycles. Regardless of the type of bicycle, its transmission system is like the heart of the bicycle, which is the force that drives the bicycle forward. The transmission system includes a central axis set on the frame, a crank with an interference fit on the central axis, a wheel, and a pedal connected to the crank. The central axis connects the crank and the wheel to the frame, and these components bear the pedaling force. Therefore, when assembling a bicycle, special attention should be paid to the assembly accuracy of the transmission system, because the crank and the central axis are in an interference fit relationship. The two cranks are squeezed with the two ends of the central axis by external force to form an interference fit connection relationship. During the assembly process, the coaxiality tolerance between the cranks on both sides and the central axis needs to be guaranteed, otherwise the rotation angle of the crank will change during the rotation process, which will cause the axis position of the pedal to change. The force transmission direction changes during the riding process, which will not only make the riding process more laborious, but also cause damage to the knees. Therefore, the quality of the crank assembly determines the overall quality of the bicycle.

[0003] As for the assembly process of the crank and the middle shaft, the mounting hole between the crank and the middle shaft is a keyway fit, and the precise manual installation is time-consuming and laborious, and external force is required to press the crank into the middle shaft. For the crank component, it includes a mounting hole that matches the middle shaft and a connecting hole connected to the pedal. The mounting hole and the connecting hole are located at both ends of the crank, and the positions of the two ends of the crank have a height difference and are not flat. Therefore, when the crank is pressed by a press, it is difficult to find a stable and balanced force point. When the crank and the middle shaft are pressed by a press, once the force is unbalanced, the coaxiality tolerance between the crank and the middle shaft will exceed the range, causing the rotation angle of the crank to change during the rotation process, affecting the final quality of the product.

[0004] For the existing assembly equipment in other fields, there are two main differences from the present application, namely, the assembly method and the pressing method. First of all, from the perspective of the assembly method, the existing assembly methods include pressing in the up-down direction and the left-right direction. Since the crank and the middle shaft are assembled on the bicycle frame, the assembly method cannot be modified to pressing in the up-down direction, because this method requires the bicycle frame to be placed horizontally, which makes it difficult to fix and balance the bicycle as a whole, thereby affecting the processing accuracy. Therefore, only the left-right centering clamping method is feasible. Therefore, a hydraulic cylinder is used to control the pressure head to synchronously press and assemble the crank. The disadvantage of this method is that the assembly process between the crank and the bottom bracket is very precise, but the specific pressure value of the hydraulic system is difficult to control and can only be maintained within a range. As a result, during assembly, the force values ​​of the cranks on both sides are different, causing the bicycle frame in a neutral position to tilt toward the side with a smaller pressure value, and causing deviations in the assembly position of the crank and the bottom bracket, and the accuracy requirements for the coordination between the two are not met. Therefore, the traditional hydraulic assembly method cannot meet current needs, so an automatic control crank gantry press and a control method thereof are needed. Summary of the invention

[0005] The purpose of the present invention is to provide an automatic control crank gantry press and a control method thereof, which is used in the assembly process of a bicycle crank and a central axis, has high assembly precision, is safer during the assembly process, greatly reduces manual operation, increases the force range of the originally uneven crank surface through a pad, makes the force more uniform, and has a better assembly effect, and can be pressed along the central axis during the pressing process. By improving the method steps in the assembly process, the defects of the hydraulic system are solved and the assembly precision is improved.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] An automatic control crank gantry press comprises a gantry frame arranged on the ground, a clamping mechanism symmetrically arranged on the gantry frame, a cushion block, a trolley, and a plurality of trolley positioning mechanisms arranged below the gantry frame; the trolley carries a single vehicle frame, the trolley positioning mechanism limits the position of the trolley, the cushion block cooperates with the mounting hole of the single vehicle crank, and the cushion block is used to increase the contact area between the crank and the clamping mechanism so that the crank is more evenly stressed; the clamping mechanism comprises a hydraulic cylinder, a pressure head connected to the hydraulic cylinder, guide rods arranged on both sides of the hydraulic cylinder, and a displacement sensor; the A pressure sensor is connected between the pressure head and the hydraulic cylinder. The pressure sensor and the pressure head are detachably connected. The two clamping mechanisms on the gantry body intermittently center and clamp the crank on one side. The stroke of the hydraulic cylinder and the pressing position are monitored by the displacement sensor. The quality of the pressing action and the quality of the fit between the crank and the workpiece are judged by the pressing position. The pressure sensor monitors the pressure range of the hydraulic cylinder acting on the crank during the entire process. The two sensors monitor the hydraulic cylinder synchronously. If any one of them does not meet the set value range, the device will issue an alarm prompt.

[0008] The cushion block comprises a stress shaft and a pressure block matched with the stress shaft; a limiting groove is arranged on the stress shaft, a limiting clamping spring is matched in the limiting groove, and the pressure block has magnetic force.

[0009] The trolley positioning mechanism comprises a fixed plate, a limit cylinder arranged on the fixed plate, a movable rod connected to the piston rod of the limit cylinder, a limit column connected to the movable rod, and an infrared sensor.

[0010] The gantry body is provided with a safety grating and an emergency stop switch.

[0011] A method for using an automatically controlled crank gantry press, S1, a worker pushes a trolley into a clamping area of ​​a clamping mechanism, and the worker installs pads into the mounting holes of the cranks on both sides of the trolley so that the stress shaft limit spring side faces outward, and after the worker safely exits, an infrared sensor controls the trolley positioning mechanism to limit the trolley;

[0012] S2, the piston rods of the hydraulic cylinders on both sides extend to drive the pressure block to contact the pad head. After contact, the pressure of the left hydraulic cylinder is greater than that of the other side, enabling it to hold the bicycle against the gasket. The piston rod of the right hydraulic cylinder is displaced to act on the pad, completing the assembly of the crank and the middle shaft on one side. Then, the pressure of the right hydraulic cylinder is greater than that of the left side. The piston rod of the left hydraulic cylinder is displaced to act on the pad, completing the assembly of the crank and the middle shaft on one side.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] 1. This device is used for assembling bicycle cranks and middle shafts. It has high assembly precision and is safer during assembly. It greatly reduces manual operations. The originally uneven crank surface is increased in force range by pads, making the force more uniform and the assembly effect better. During the clamping process, it can be clamped along the middle shaft direction. By improving the method and steps in the assembly process, the defects of the hydraulic system are solved and the assembly precision is improved.

[0015] 2. The division of labor between high-pressure fixing and low-pressure pressing enables each operation stage to be completed faster. The operation process is highly stable, and the pressing data is monitored all the time, which can reduce the number of reworks caused by precision problems, thereby improving overall efficiency. It can also meet the pressing force requirements of different workpieces and improve production flexibility.

[0016] 3. Prevent the crank from deflecting or shaking during the press-in process. Low-pressure and slow press-in helps reduce the impact force and ensure that the crank and accessories fit more closely and accurately. By switching between high and low pressure, the disadvantages of high pressure on both sides mentioned above can be avoided, and excessive stress caused by using high pressure throughout the process can be avoided, reducing the risk of damage or deformation of the workpiece. The press-in process is smooth and suitable for press-fitting workpieces with high precision requirements. At the same time, high-low pressure switching effectively reduces excessive concentration of press-in force, avoids excessive wear on the hydraulic cylinder and pressure head, and extends the service life of the equipment. It can also reduce impact loads and help reduce maintenance costs. High-low pressure switching reduces the peak pressure of the hydraulic press during operation, which helps to improve the safety of the equipment. Low-pressure operation consumes less energy and achieves energy consumption optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Attached Figure 1 It is an overall view of the device of the present invention.

[0018] Attached Figure 2 This is a view of the device of the present invention without the external cover.

[0019] Attached Figure 3 It is a view of the clamping mechanism in the present invention.

[0020] Attached Figure 4 It is a view of the trolley limiting mechanism in the present invention.

[0021] Attached Figure 5 It is an assembly view of the crank and the cushion block in the present invention.

[0022] Attached Figure 6 It is a view of the cushion block in the present invention.

[0023] Numbers shown in the accompanying drawings:

[0024] 1. Gantry frame; 2. Pad; 3. Trolley; 4. Crank; 5. Hydraulic cylinder; 6. Pressure head; 7. Guide rod; 8. Displacement sensor; 9. Stress axis; 10. Pressure block; 11. Limiting spring; 12. Fixed plate; 13. Limiting cylinder; 14. Movable rod; 15. Limiting column; 16. Infrared sensor; 17. Middle axis; 18. Pressure sensor. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the application equally.

[0026] The present invention discloses an automatic control crank 4 gantry press and a control method thereof, wherein the main structure comprises a gantry frame 1 arranged on the ground, a clamping mechanism symmetrically arranged on the gantry frame 1, a cushion block 2, a trolley 3, and a plurality of trolley positioning mechanisms arranged below the frame;

[0027] Trolley 3: Trolley 3 is a fixed bicycle frame. Before assembling crank 4, crank 4 needs to be manually sleeved on the middle shaft 17, and then the trolley 3 is pushed into the clamping area of ​​the clamping mechanism. In order to fix the trolley 3 as a whole, the trolley positioning mechanism limits the position of the trolley 3, as shown in the figure of the specification. Figure 1 and Figure 4 As shown, the trolley positioning mechanism includes a fixed plate 12 arranged on the gantry frame 1, a limit cylinder 13 arranged on the fixed plate 12, a movable rod 14 connected to the piston rod of the limit cylinder 13, a limit column 15 connected to the movable rod 14, and an infrared sensor 16. When the infrared sensor 16 detects that the trolley 3 enters the clamping area and the operator exits the operating area, the infrared sensor 16 controls the limit cylinder 13 to move, and the piston rod of the limit cylinder 13 drives the movable rod 14 and the limit column 15 to move together, thereby blocking and limiting the trolley 3, thereby ensuring stability during operation.

[0028] Pad 2: After the trolley 3 is manually pushed into the compacting area, as shown in the attached figure of the specification Figure 5 and Figure 6As shown, the pad 2 needs to be placed in the mounting hole of the crank 4. The pad 2 includes a stress shaft 9 and a pressure block 10 that cooperates with the stress shaft 9. The length of the stress shaft 9 is less than the depth of the mounting hole. A limiting groove is provided on the stress shaft 9. A limiting retaining spring 11 is provided in the limiting groove. The pressure block 10 has magnetic force. When in use, the stress shaft 9 is inserted into the mounting hole of the crank 4, and the limiting retaining spring 11 is located on the outside. When the clamping mechanism acts on the stress shaft 9, the stress shaft 9 transmits the pressure to the pressure block 10 through the limiting retaining spring 11. The pressure block 10 uniformly applies stress to the surface of the crank 4, thereby preventing uneven stress distribution from affecting the assembly effect of the crank 4 and the middle shaft 17, and solving the problem of irregular surface shape of the crank 4. The pressure block 10 has magnetic force and can be directly adsorbed on the surface of the crank 4, so that the pad 2 will not fall out of the mounting hole of the crank 4. Since the diameter of the stress axis 9 is smaller than the diameter of the mounting hole, if there is no magnetic force, the position of the pressure block 10 will be affected by gravity and will not fit the surface of the crank 4. As a result, when the hydraulic cylinder 5 drives the pressure head 6 to press in, the position of the pressure block 10 may not reach the preset position, and pressure fluctuations may occur during the pressing process, thereby affecting the stability of the pressing process.

[0029] As shown in the attached figure of the instruction manual Figure 2 and Figure 3 As shown, the clamping mechanism: The clamping mechanism is symmetrically arranged on the gantry frame 1, so as to realize the intermittent centering and clamping of the trolley 3 on the crank 4 on one side. The clamping mechanism includes a hydraulic cylinder 5, a pressure head 6 connected to the hydraulic cylinder 5, a guide rod 7 arranged on both sides of the hydraulic cylinder 5, and a displacement sensor 8. The displacement sensor 8 is arranged on the rear side of the hydraulic cylinder 5. The two guide rods 7 are connected by an L-shaped connecting plate. When the hydraulic cylinder 5 is displaced, the guide rod 7 and the L-shaped connecting plate are driven to displace. The displacement sensor 8 detects the displacement distance of the L-shaped connecting plate and then determines the displacement distance of the hydraulic cylinder 5. The stroke of the hydraulic cylinder 5 and the measurement of the pressing position are monitored by the displacement sensor 8, and the completion quality of the pressing action and the quality of the match between the crank and the workpiece are judged by the displacement distance of the pressing position.

[0030] A pressure sensor 18 is connected between the pressure head 6 and the hydraulic cylinder 5. The pressure sensor 18 is detachably connected to the pressure head 6. The pressure sensor 18 is used to monitor the pressure range value of the workpiece during the pressing process in real time, and the control center can receive real-time feedback on the pressure value of the workpiece. The oil circuit of the hydraulic cylinder 5 is also connected with a solenoid valve, which is used to control the pressure of the hydraulic cylinder 5. The displacement sensor 8 controls the extension distance of the pressure block 10 driven by the hydraulic cylinder 5, and then controls the matching distance between the crank 4 and the central axis 17. The pressure sensor 18 and the displacement sensor 8 work together to control the hydraulic cylinder 5. The displacement sensor 8 controls the displacement distance of the hydraulic cylinder 5, and the pressure sensor 18 controls the pressure of the hydraulic cylinder 5 on the crank. When any value monitored by the two does not meet the set value range, the equipment will issue an alarm, allowing the engineer or operator to determine the situation and then implement the disposal plan.

[0031] Because the device requires manual operation, in order to improve the safety of the device, a safety grating and an emergency stop switch are provided on the gantry body 1 to prevent emergency situations.

[0032] The specific operation steps for the device are as follows:

[0033] S1, first the worker pushes the trolley 3 into the clamping area of ​​the clamping mechanism, and then installs the pad 2 into the mounting holes of the cranks 4 on both sides of the bicycle, so that the stress shaft 9 limit spring 11 side faces outward. After the safety grating detects that the worker has safely exited, the start button is pressed, and the infrared sensor 16 controls the extension of the cylinder of the trolley positioning mechanism on the gantry frame 1 to limit the trolley 3 within the clamping area.

[0034] After the overall positioning of the trolley 3 is completed, the crank 4 needs to be assembled. However, for hydraulic equipment, there is a disadvantage that the oil circuit control part is unstable and the accuracy is not high during the hydraulic process. Therefore, when the two symmetrically arranged clamping mechanisms are centered and clamped at the same time, different pressures may appear on both sides, affecting the final assembly effect and accuracy. Therefore, the solution is as follows:

[0035] S2, the piston rods of the hydraulic cylinders 5 on both sides extend to drive the pressure head 6 to contact the cushion block 2. The pressure of the left hydraulic cylinder 5 is greater than that of the other side, so that it can resist the bicycle. The piston rod of the right hydraulic cylinder 5 is displaced to act on the cushion block 2, so that the crank 4 on one side and the middle axis 17 are assembled. Then the pressure of the hydraulic cylinder 5 on the right side is greater than that on the left side. The piston rod of the left hydraulic cylinder 5 is displaced to act on the cushion block 2, so that the crank 4 on one side and the middle axis 17 are assembled. After approaching, the first step is to increase the pressure on one side so that it can be used as a supporting surface to resist the bicycle, to prevent the bicycle body from being skewed during the assembly of the crank 4 due to excessive pressure on one side. Then the hydraulic cylinder 5 on the other side is extended and acts on the stress axis 9 of the cushion block 2, thereby realizing the unilateral assembly. The assembly process on the other side is the same as above. After the assembly on both sides is completed, the cushion block 2 is manually removed from the mounting hole of the crank 4 axis, and then the trolley 3 is pushed away.

[0036] In summary, in step S2, when the pressure is switched between the left hydraulic cylinder and the right hydraulic cylinder, high pressure is used on one side to fix the workpiece, and low pressure is used on the other side to press in slowly. The high pressure provides a stable supporting force, and the side switching operation is performed after completion.

[0037] Prevent the crank 4 from deflecting or shaking during the pressing process. Low-pressure and slow pressing helps reduce the impact force and ensure that the crank 4 and the accessories fit more closely and accurately. The disadvantage of high pressure on both sides mentioned above can be avoided by switching between high and low pressures, and excessive stress caused by using high pressure throughout the process can be avoided, reducing the risk of damage or deformation of the workpiece. The pressing process is smooth and suitable for pressing workpieces with high precision requirements. At the same time, the high-low pressure switching effectively reduces the excessive concentration of the pressing force, avoids excessive wear on the hydraulic cylinder 5 and the pressure head 6, and extends the service life of the equipment. It can also reduce impact loads and help reduce maintenance costs. The high-low pressure switching reduces the peak pressure of the hydraulic press during operation, which helps to improve the safety of the equipment. Low-pressure operation consumes less energy, achieving energy consumption optimization.

Claims

1. An automatic control crank gantry press, characterized in that: It comprises a gantry frame (1) arranged on the ground, a pressing mechanism symmetrically arranged on the gantry frame (1), a cushion block (2), a trolley (3), and a plurality of trolley positioning mechanisms arranged below the gantry frame; The trolley (3) carries a bicycle frame, the trolley positioning mechanism limits the position of the trolley (3), the cushion block (2) cooperates with the mounting hole of the bicycle crank (4), the cushion block (2) is used to increase the contact area between the crank (4) and the clamping mechanism so that the crank (4) is subjected to more uniform force, the cushion block (2) comprises a stress shaft (9) and a pressure block (10) matched with the stress shaft (9), the stress shaft (9) is provided with a limiting groove, a limiting clamping spring (11) is matched in the limiting groove, and the pressure block (10) has a magnetic force; The clamping mechanism comprises a hydraulic cylinder (5), a pressure head (6) connected to the hydraulic cylinder (5), guide rods (7) arranged on both sides of the hydraulic cylinder (5), and a displacement sensor (8); The trolley positioning mechanism comprises a fixed plate (12), a limit cylinder (13) arranged on the fixed plate (12), a movable rod (14) connected to the piston rod of the limit cylinder (13), a limit column (15) connected to the movable rod (14), and an infrared sensor (16); A pressure sensor (18) is connected between the pressure head (6) and the hydraulic cylinder (5). The pressure sensor (18) and the pressure head (6) are detachably connected. The two clamping mechanisms on the gantry frame (1) perform intermittent centering and clamping on one side of the crank (4). The travel and the pressing position of the hydraulic cylinder (5) are monitored by the displacement sensor (8). The quality of the pressing action and the quality of the fit between the crank and the workpiece are determined by the pressing position. The pressure sensor (18) monitors the pressure range value of the hydraulic cylinder (5) acting on the crank during the entire process. The two sensors monitor the hydraulic cylinder (5) synchronously. If any of the monitored values ​​does not meet the set value range, the device will issue an alarm prompt.

2. The automatic control crank gantry press according to claim 1, characterized in that: The gantry body (1) is provided with a safety grating and an emergency stop switch.

3. The method for using the automatic controlled crank gantry press according to claim 1 or 2, characterized in that: S1, the worker pushes the trolley (3) into the clamping area of ​​the clamping mechanism, and installs the pads (2) into the mounting holes of the cranks (4) on both sides of the bicycle so that the side of the limit spring (11) of the stress shaft (9) faces outward. After the worker safely exits, the infrared sensor (16) controls the trolley positioning mechanism to limit the trolley (3); S2, the piston rods of the hydraulic cylinders (5) on both sides extend to drive the pressure head (6) to contact the cushion block (2). After the contact, the pressure of the left hydraulic cylinder (5) is greater than that of the other side, so that it can resist the bicycle, and the piston rod of the right hydraulic cylinder (5) is displaced to act on the cushion block (2), so that the crank (4) on one side and the middle shaft (17) are assembled; then the pressure of the right hydraulic cylinder (5) is greater than that of the left side, and the piston rod of the left hydraulic cylinder (5) is displaced to act on the cushion block (2), so that the crank (4) on one side and the middle shaft (17) are assembled.

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