Hard stop dowel mechanism

Abstract

This utility model relates to the technical field of biscuit processing equipment, specifically a hard-limit positioning pin mechanism. It includes a frame, a drive shaft located at the center of the top surface of the frame, a turntable mounted on the top of the drive shaft, and positioning components mounted on the outer circumference of the drive shaft. Multiple positioning seats are mounted on the top surface of the frame, circumferentially along the drive shaft. Rotation of the drive shaft causes the positioning components to engage with positioning seats at different positions. In this hard-limit positioning pin mechanism, the engagement of the positioning components and positioning seats forms a hard-limit structure. The arc-shaped design of the positioning head and positioning groove, combined with the preload of a spring, allows for precise engagement when the drive shaft drives the turntable to a preset position. This mechanism directly constrains the positional deviation of the turntable through mechanical hard limiting, effectively solving the problem of cumulative errors caused by speed fluctuations and component wear. It avoids misalignment between the forming cavity and the processing components, fundamentally eliminating uneven distribution of compressed biscuit raw materials and deformation of the shape.

Description

Technical Field

[0001] This utility model relates to the field of biscuit processing equipment technology, and more specifically, to a hard limit positioning pin mechanism. Background Technology

[0002] In the production and processing equipment of the baking food industry, especially in automated equipment such as compressed biscuit forming machines, the precise positioning of the turntable directly affects the product forming quality and production continuity. As the market's requirements for the taste and shape precision of compressed biscuits and other baked goods continue to increase, the positioning stability of the equipment has become a key factor restricting production efficiency. In the prior art, patent application number 202311421516.9 discloses a compressed biscuit forming machine, which uses a rotating turntable to sequentially connect the forming cavity with the feeding component and the pressing block, and uses a piston and pressing block to complete the compression forming of the raw materials. However, the turntable positioning structure of this equipment has obvious limitations in actual operation: it relies on the coordination of conventional rotating connections and drive components to achieve position alignment, and does not have a dedicated hard limit positioning mechanism. As a result, when the turntable speed fluctuates (especially in medium-speed operation scenarios of 10-12 rpm), positioning deviations are easily caused by inertial impact and component wear. Through actual application verification, after the equipment has been running for a period of time, the cumulative error can cause the alignment deviation between the forming cavity and the pressing block to exceed ±1mm. This not only causes uneven distribution of compressed biscuit raw materials and deformation of the shape, but also results in a deviation of up to 6 pieces per mold, which seriously affects the product qualification rate. Furthermore, the existing calibration method relies on parameter adjustment of the drive components, lacking a convenient mechanical calibration structure. When positioning accuracy decreases, calibration requires stopping the machine and adjusting the drive program or mechanical transmission clearance, which is complex and time-consuming, significantly increasing equipment downtime and maintenance costs. For large-scale production, these shortcomings in positioning accuracy and inconvenient calibration are insufficient to meet the baking industry's demands for efficient and high-precision processing. Therefore, developing a hard-limit positioning pin mechanism that can achieve ±0.3mm repeatability and facilitates rapid calibration has become a key technological breakthrough for solving the positioning defects of existing compressed biscuit forming machines. Utility Model Content

[0003] The purpose of this utility model is to provide a hard limit positioning pin mechanism to solve the problem mentioned in the background art. After actual application verification, the cumulative error of the equipment after running for a period of time can cause the alignment deviation between the molding cavity and the pressing block to exceed ±1mm. This not only causes uneven distribution of compressed biscuit raw materials and deformation of shape, but also results in a deviation of up to 6 pieces per mold, which seriously affects the product qualification rate.

[0004] To achieve the above objectives, this utility model provides a hard limit positioning pin mechanism, including a frame, a drive shaft disposed in the middle of the top surface of the frame, a turntable mounted on the top of the drive shaft, a positioning component mounted on the outer circumferential wall of the drive shaft, and multiple positioning seats mounted on the top surface of the frame in the circumferential direction of the drive shaft. The rotation of the drive shaft drives the positioning component to cooperate with the positioning seats at different positions.

[0005] This setup uses a frame as a support base, with a drive shaft rotating the turntable. Simultaneously, positioning components on the outer circumference of the drive shaft rotate with it, dynamically engaging with positioning seats on the frame. This structure utilizes mechanical hard contact to achieve turntable positioning, replacing the traditional soft positioning method that relies on the coordination of drive components.

[0006] Preferably, the number of positioning seats is four, and they are arranged in a ring with equal spacing around the center of the drive shaft.

[0007] This setup features four positioning seats arranged in a ring with equal spacing around the drive shaft, corresponding one-to-one with the number of molds on the turntable, ensuring that a positioning engagement is triggered every 90° rotation of the turntable.

[0008] Preferably, the turntable has several threaded holes at the top edge, and a calibration pin is threaded through each threaded hole. A calibration pin sleeve is installed on the top surface of the frame near the bottom of each calibration pin, and the bottom of the calibration pin can be inserted into the calibration pin sleeve.

[0009] This setting involves a threaded hole on the circumference of the turntable that mates with a calibration pin. The bottom of the calibration pin is inserted into the calibration pin sleeve of the frame, forming a mechanical calibration reference independent of the main positioning system.

[0010] Preferably, the bottom of the calibration pin is provided with an external thread, the inside of the calibration pin sleeve is provided with a threaded groove, the bottom of the calibration pin is inserted into the internal thread of the calibration pin sleeve, and a handle is installed on the top of the calibration pin, with the bottom surface of the handle abutting against the top surface of the turntable.

[0011] This setting creates a rigid locking force through the threaded connection between the calibration pin and the calibration pin sleeve. The handle achieves axial limitation by adhering to the surface of the turntable. This double constraint ensures that the position of the turntable does not shift slightly during the calibration process.

[0012] Preferably, the positioning component includes a movable sleeve, a fixed shaft is inserted into the inner end of the movable sleeve, a positioning head is installed on the outer end of the movable sleeve, a positioning groove is formed on the inner end face of the positioning seat, the positioning head is engaged with the positioning groove, the inner end of the fixed shaft is installed on the outer circumferential wall of the drive shaft, and a spring is sleeved on the outside of the fixed shaft.

[0013] In this positioning component, the fixed shaft provides guidance, and the movable sleeve can slide along the fixed shaft. The preload of the spring pushes the positioning head to engage with the positioning groove. When the turntable rotates, the positioning head is squeezed and compressed by the inclined surface of the positioning seat, disengaging from the positioning groove. After it reaches the correct position, the spring resets to achieve engagement.

[0014] Preferably, the inner wall of the positioning groove is an arc-shaped structure, the outer wall of the positioning head is an arc-shaped structure, and both are made of rubber material, and the shape of the positioning head is adapted to the positioning groove.

[0015] This feature allows the positioning groove to make surface contact with the curved surface of the positioning head. The rubber positioning head has elastic deformation capability, which can compensate for minor dimensional errors and absorb collision energy.

[0016] Preferably, a drive motor is installed in the middle of the frame, and the output shaft of the drive motor is connected to the bottom of the drive shaft.

[0017] This setting allows the drive motor to provide power to the drive shaft, and the output shaft to be directly connected to the drive shaft to achieve power transmission.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: In this hard-limit positioning pin mechanism, the positioning component and the positioning seat cooperate to form a hard-limit structure. The arc-shaped adaptation design of the positioning head and the positioning groove, combined with the preload of the spring, enables precise engagement when the drive shaft drives the turntable to rotate to the preset position. This mechanism directly constrains the positional deviation of the turntable through mechanical hard limiting, effectively solving the problem of cumulative errors caused by speed fluctuations and component wear. It fundamentally eliminates uneven distribution of compressed biscuit ingredients and shape deformation, significantly improving the product qualification rate. The threaded connection between the calibration pin and the calibration pin sleeve, combined with the handle's fitting and positioning design, constitutes a convenient mechanical calibration component. When the positioning accuracy decreases after long-term operation, the operator does not need to adjust the drive program or mechanical transmission clearance. Simply screw the calibration pin into the calibration pin sleeve using the handle, and the rigid constraint of the threaded fit will forcefully correct the turntable position. The entire calibration process is simple and quick. Compared to the complex calibration methods in existing technologies that rely on adjusting drive component parameters, this mechanism significantly reduces equipment downtime for maintenance, reduces reliance on professional technicians, and significantly improves the continuous operation efficiency of the production line. The sliding fit between the fixed shaft and the movable sleeve in the positioning component, combined with the buffering effect of the spring, effectively absorbs the inertial impact during turntable rotation, reducing contact wear between the positioning head and the positioning groove. Simultaneously, the rubber positioning head ensures a tight fit while providing a certain degree of elastic cushioning, preventing damage to components caused by rigid collisions. Furthermore, the threaded connection structure between the calibration pin and the calibration pin sleeve has high strength, allowing for repeated use without deformation, further enhancing the overall durability of the mechanism and reducing long-term maintenance costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a top view of the frame structure in this utility model; Figure 3 This is a schematic diagram of the positioning component in this utility model; Figure 4 This is a schematic diagram of the calibration pin in this utility model; The meanings of the labels in the diagram are as follows: 1. Frame; 11. Positioning seat; 111. Positioning groove; 12. Calibration pin sleeve; 121. Threaded groove; 2. Turntable; 21. Drive shaft; 22. Threaded hole; 3. Positioning component; 31. Movable sleeve; 32. Fixed shaft; 33. Positioning head; 34. Spring; 4. Calibration pin; 41. Handle. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] This utility model provides a hard limit positioning pin mechanism, such as Figure 1 , Figure 2 As shown, the device includes a frame 1, a drive shaft 21 is provided in the middle of the top surface of the frame 1, a turntable 2 is installed on the top of the drive shaft 21, a positioning component 3 is installed on the outer circumferential wall of the drive shaft 21, and multiple positioning seats 11 are installed on the top surface of the frame 1 in the circumferential direction of the drive shaft 21. The rotation of the drive shaft 21 drives the positioning component 3 to cooperate with the positioning seats 11 in different positions.

[0022] In use, the frame 1 provides a supporting base, and the drive shaft 21 drives the turntable 2 to rotate. Simultaneously, the positioning component 3 on the outer circumference of the drive shaft 21 rotates with it, dynamically engaging with the positioning seats 11 at different positions on the frame 1. This structure utilizes mechanical hard contact to achieve the station positioning of the turntable 2, replacing the traditional soft positioning method that relies on the coordination of drive components. This structural design establishes a core framework for hard-limit positioning. Through the direct engagement of the positioning component 3 and the positioning seat 11, it provides rigid constraints to the turntable 2, fundamentally improving positioning stability and avoiding positional deviations caused by drive system errors.

[0023] In this embodiment, as Figure 1 , Figure 2As shown, there are four positioning seats 11, which are arranged in a ring with equal spacing around the axis of the drive shaft 21.

[0024] In use, the four positioning seats 11 are arranged in a ring with equal spacing around the drive shaft 21, corresponding one-to-one with the number of molds on the turntable 2 (usually 4 sets). This ensures that the positioning component 3 and the positioning seat 11 are engaged once every 90° rotation of the turntable 2. This structural design precisely matches the station requirements of the turntable 2, ensuring that the forming cavity can accurately align with the material feeding, pressing and other processing components after each rotation. This avoids station deviations caused by uneven distribution of the positioning seats 11 and improves the consistency of multi-mold processing.

[0025] Specifically, such as Figure 1 , Figure 2 As shown, the top edge of the turntable 2 has several threaded holes 22, and each threaded hole 22 has a calibration pin 4 threaded through it. A calibration pin sleeve 12 is installed on the top surface of the frame 1 near the bottom of each calibration pin 4, and the bottom of the calibration pin 4 is inserted into the calibration pin sleeve 12. There are four calibration pins 4 and four calibration pin sleeves 12, and they are distributed in a ring with equal spacing.

[0026] In use, the threaded hole 22 on the top surface of the turntable 2 engages with the calibration pin 4, and the bottom of the calibration pin 4 is inserted into the calibration pin sleeve 12 on the top surface of the frame 1, forming a mechanical calibration reference independent of the main positioning system of the positioning component 3 and the positioning seat 11. This structural design provides a convenient secondary calibration channel. When the positioning component 3 or the positioning seat 11 in the main positioning system experiences wear or error accumulation, the position of the turntable 2 can be forcibly corrected through the engagement of the calibration pin 4 and the calibration pin sleeve 12, ensuring the ability to restore positioning accuracy during long-term use.

[0027] Furthermore, such as Figure 4 As shown, the bottom of the calibration pin 4 is provided with an external thread, the inside of the calibration pin sleeve 12 is provided with a threaded groove 121, the bottom of the calibration pin 4 is inserted into the internal thread of the calibration pin sleeve 12, and a handle 41 is installed on the top of the calibration pin 4, with the bottom surface of the handle 41 abutting against the top surface of the turntable 2.

[0028] During use, the threaded connection between calibration pin 4 and calibration pin sleeve 12 generates a rigid locking force. Handle 41 achieves axial positioning by adhering to the surface of turntable 2. This dual constraint ensures that the position of turntable 2 does not shift slightly during calibration, and the threaded hole 22 provides stable support for calibration pin 4. The self-locking characteristic of the threaded fit ensures the positional stability after calibration. The adhering design of handle 41 simplifies the operation of judging whether the installation is in place, allowing ordinary operators to complete the calibration process without professional tools, greatly reducing maintenance difficulty.

[0029] Furthermore, such as Figure 3As shown, the positioning component 3 includes a movable sleeve 31, with a fixed shaft 32 inserted into its inner end. A positioning head 33 is mounted on the outer end of the movable sleeve 31. A positioning groove 111 is formed on the inner end face of the positioning seat 11, and the positioning head 33 engages with the positioning groove 111. The inner end of the fixed shaft 32 is mounted on the outer circumferential wall of the drive shaft 21, and a spring 34 is sleeved on the outside of the fixed shaft 32. One end of the spring 34 is fixedly connected to the inner end face of the movable sleeve 31, and the other end is connected to the outer wall of the drive shaft 21. When the spring 34 is in its natural extension state, the outer end of the fixed shaft 32 is located inside the inner end of the movable sleeve 31.

[0030] In use, in positioning component 3, the fixed shaft 32 provides guidance, and the movable sleeve 31 can slide along the fixed shaft 32. The preload of the spring 34 pushes the positioning head 33 to engage with the positioning groove 111 on the positioning seat 11. When the turntable 2 rotates, the positioning head 33 is compressed by the inclined surface of the positioning seat 11, disengaging from the positioning groove 111. After repositioning, the spring 34 returns to its original position, thus achieving engagement. The elastic force of the spring 34 ensures that the positioning head 33 fits tightly with the positioning groove 111, while allowing the turntable 2 to smoothly switch between positioning and disengagement during rotation. This ensures positioning accuracy and avoids damage to the positioning component 3 and the positioning seat 11 caused by rigid collisions.

[0031] Furthermore, such as Figure 2 As shown, the inner wall of the positioning groove 111 is an arc-shaped structure, and the outer wall of the positioning head 33 is an arc-shaped structure and is made of rubber material. The shape of the positioning head 33 is adapted to the positioning groove 111.

[0032] In use, the inner wall of the positioning groove 111 and the outer wall of the positioning head 33 are both arc-shaped, forming a surface contact. The positioning head 33 is made of rubber, possessing elastic deformation capability, which can compensate for minor dimensional errors and absorb collision energy. This arc-shaped fit increases the contact area between the positioning head 33 and the positioning groove 111, improving positioning stability. The rubber positioning head 33 reduces metal-to-metal friction noise, lowers the wear rate of the positioning seat 11 and the positioning head 33, and simultaneously, through elastic buffering, avoids impact vibration when the turntable 2 rotates into position, extending the service life of the mechanism.

[0033] Furthermore, a drive motor is installed in the middle of the interior of the frame 1, and the output shaft of the drive motor is connected to the bottom of the drive shaft 21.

[0034] In use, the drive motor in the middle of the frame 1 provides power to the drive shaft 21, and its output shaft is directly connected to the drive shaft 21 to achieve power transmission. This direct drive motor reduces transmission errors and ensures the rotational speed accuracy of the turntable 2. Combined with the hard limit positioning structure formed by the positioning component 3 and the positioning seat 11, it further reduces the cumulative error caused by speed fluctuations and ensures the deviation in the number of molded products per mold.

[0035] In use, the hard-limit positioning pin mechanism of this utility model drives the positioning component 3 to rotate synchronously with the turntable 2. The preload of the spring 34 pushes the positioning head 33 to periodically engage with the positioning groove 111 of the positioning seat 11, thus mechanically constraining the circumferential position of the turntable 2 through hard contact. When long-term operation leads to a decrease in positioning accuracy, the relative position of the turntable 2 and the frame 1 is forcibly corrected through the threaded connection between the calibration pin 4 and the calibration pin sleeve 12, restoring the positioning reference. The drive motor directly drives the drive shaft 21, reducing transmission errors, and is further enhanced by the arc-shaped contact of the positioning component 3 and the cushioning effect of the rubber material. Work process The drive motor inside the frame 1 starts, and the output shaft drives the drive shaft 21 to rotate, which in turn drives the turntable 2 at the top to rotate. At this time, the positioning component 3 on the outer circumference of the drive shaft 21 rotates synchronously with it, the movable sleeve 31 slides freely on the fixed shaft 32, and the spring 34 is in a natural pre-tension state. When the turntable 2 rotates to the preset position, the positioning head 33 meets the positioning seat 11. Guided by the inclined surface of the positioning seat 11, the positioning head 33 compresses the spring 34 and retracts along the fixed shaft 32 until it is fully engaged in the positioning groove 111. Since both the positioning groove 111 and the positioning head 33 are curved surfaces and their shapes are compatible, the rubber positioning head 33 undergoes a slight deformation, forming a tight surface contact with the positioning groove 111, thus locking the positional accuracy of the turntable 2 within ±0.3mm. As the turntable 2 continues to rotate, the positioning head 33 is once again squeezed out of the positioning groove 111 by the inclined plane, and the spring 34 resets, pushing the movable sleeve 31 to reset, waiting for the next positioning seat 11 to dock. The four equally spaced annular positioning seats 11 ensure that the turntable 2 completes one positioning every 90° of rotation, accurately matching the processing requirements of the four sets of molds. When a positioning deviation exceeding the threshold is detected, the machine is stopped, and the calibration pin 4 is inserted into the threaded hole 22 on the turntable 2. The handle 41 is rotated so that the bottom thread of the calibration pin 4 is inserted into the calibration pin sleeve 12. As the thread tightens, the bottom surface of the handle 41 gradually contacts the top surface of the turntable 2, forcibly adjusting the position of the turntable 2 through the rigid constraint of the thread until the positioning component 3 and the positioning seat 11 return to the standard fit. After calibration, the handle 41 is rotated in the opposite direction, and the calibration pin 4 is removed to restart the equipment. During long-term operation, the rubber material of the positioning head 33 compensates for minor wear through elastic deformation, and the continuous preload of the spring 34 ensures that the positioning head 33 and the positioning groove 111 are always in close contact. The direct drive method of the drive motor reduces speed fluctuations, and together with the hard limit structure, ensures the continuity and consistency of biscuit processing.

[0036] Finally, it should be noted that the electronic components in the drive motor and other components mentioned above in this embodiment are all general standard parts or parts known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires respectively. The specific connection method should refer to the working order between each electrical component in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model 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 utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A hard limit positioning pin mechanism, comprising a frame (1), characterized in that: A drive shaft (21) is provided in the middle of the top surface of the frame (1). A turntable (2) is installed on the top of the drive shaft (21). A positioning component (3) is installed on the outer circumferential wall of the drive shaft (21). Multiple positioning seats (11) are installed on the top surface of the frame (1) and in the circumferential direction of the drive shaft (21). The rotation of the drive shaft (21) drives the positioning component (3) to cooperate with the positioning seats (11) in different positions.

2. The hard-limit positioning pin mechanism according to claim 1, characterized in that: The number of positioning seats (11) is four, and they are arranged in a ring with equal spacing around the axis of the drive shaft (21).

3. The hard-limit positioning pin mechanism according to claim 1, characterized in that: The turntable (2) has several threaded holes (22) at the top edge. Each threaded hole (22) is threaded with a calibration pin (4). A calibration pin sleeve (12) is installed on the top surface of the frame (1) near the bottom of each calibration pin (4). The bottom of the calibration pin (4) can be inserted into the calibration pin sleeve (12).

4. The hard-limit positioning pin mechanism according to claim 3, characterized in that: The bottom of the calibration pin (4) is provided with an external thread, the inside of the calibration pin sleeve (12) is provided with a threaded groove (121), the bottom of the calibration pin (4) is inserted into the internal thread of the calibration pin sleeve (12), and a handle (41) is installed on the top of the calibration pin (4), the bottom surface of the handle (41) is attached to the top surface of the turntable (2).

5. The hard-limit positioning pin mechanism according to claim 1, characterized in that: The positioning component (3) includes a movable sleeve (31), a fixed shaft (32) is inserted into the inner end of the movable sleeve (31), a positioning head (33) is installed on the outer end of the movable sleeve (31), a positioning groove (111) is opened on the inner end face of the positioning seat (11), the positioning head (33) is engaged with the positioning groove (111), the inner end of the fixed shaft (32) is installed on the outer circumferential wall of the drive shaft (21), and a spring (34) is sleeved on the outside of the fixed shaft (32).

6. The hard-limit positioning pin mechanism according to claim 5, characterized in that: The inner wall of the positioning groove (111) is an arc-shaped structure, and the outer wall of the positioning head (33) is an arc-shaped structure and is made of rubber material. The shape of the positioning head (33) is adapted to the positioning groove (111).

7. The hard-limit positioning pin mechanism according to claim 5, characterized in that: A drive motor is installed in the middle of the frame (1), and the output shaft of the drive motor is connected to the bottom of the drive shaft (21).

Images