Modular quick-change die system for corrugated board creasing machine

Abstract

This invention relates to the field of packaging machinery technology and discloses a modular quick-change bottom mold system for a corrugated cardboard creasing machine, including an operating table, a bottom mold, a locking mechanism, a punch holder, a fine-tuning mechanism, and a vertical drive mechanism. Guide rails are arranged on the upper surface of the operating table along the cardboard feeding direction, and the bottom mold is slidably assembled within the guide rails. The locking mechanism is located on the bottom mold and converts lateral force into vertical clamping force by pressing the sidewall of the guide rail, achieving frictional self-locking fixation of the bottom mold relative to the guide rail. The punch holder is mounted on a transverse support beam above the operating table, and the fine-tuning mechanism is installed on a sliding base of the punch holder. The fine-tuning mechanism drives the sliding base to produce linear displacement along the transverse moving axis, achieving precise alignment between the punch and the creasing groove of the bottom mold. The power output end of the vertical drive mechanism is connected to a movable blade holder to provide downward punching load. This invention solves the problems of cumbersome bottom mold replacement and low alignment accuracy in existing equipment, achieving rapid mold replacement and high-precision collaborative locking.

Description

Technical Field

[0001] This invention relates to the field of packaging machinery technology, and in particular to a modular quick-change bottom mold system for a corrugated cardboard creasing machine. Background Technology

[0002] In the corrugated cardboard processing, creasing machines are used to press fold lines onto the surface of the cardboard to produce pre-crimped, folded, quick-opening, self-locking, integrated glue-free cartons. These machines typically use a punch with an arc-shaped cross-section in conjunction with a bottom die punch groove to control the pre-crimping depth within 55% to 65% of the cardboard thickness, thereby avoiding problems such as straight-cut breaks, folding jams, or tears.

[0003] To meet the processing needs of different sized cartons, operators need to frequently change the bottom mold and readjust the position of the upper punch. Existing creasing equipment primarily uses bolts to connect and fix the bottom mold assembly to the worktable during installation and replacement. This traditional bolt-fixing structure requires pre-machining numerous bottom mold screw holes on the worktable surface and using a large number of matching bolts. This not only increases the amount of standard parts used but also increases the complexity and time cost of drilling and tapping during machining.

[0004] In actual mold changing operations, operators must use tools to remove and tighten the bolts one by one. The disassembly and assembly steps are cumbersome, resulting in an extremely slow bottom mold replacement speed and significantly reducing the effective operating time of the equipment. Furthermore, after each replacement, the bolt-fixed bottom mold still requires manual and repeated adjustment of the punch holder to ensure the alignment accuracy of the punch and punch groove. Existing equipment lacks a mechanical structure capable of quickly guiding and easily locking the bottom mold, leading to low overall mold changing efficiency and making it difficult to meet the production demands for rapid mold changes in modern packaging processing. Summary of the Invention

[0005] The purpose of this invention is to provide a modular quick-change bottom die system for a corrugated cardboard creasing machine, which solves the problems of cumbersome alignment of the upper and lower dies, difficulty in controlling positioning accuracy, and easy displacement of the die due to lateral impact during the stamping operation when changing the bottom die of existing corrugated cardboard creasing machines.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a modular quick-change bottom die system for a corrugated cardboard creasing machine, comprising:

[0008] An operating table, wherein a guide rail is arranged on the upper surface of the operating table along the paperboard feeding direction, and a transverse support beam is provided above the operating table;

[0009] A bottom mold is assembled inside the guide rail. The bottom protrusion of the bottom mold matches the cross section of the guide rail. An indentation groove is formed on the surface of the bottom mold. The bottom mold moves linearly along the guide rail.

[0010] A locking mechanism is provided on the bottom mold and is used to apply a lateral force to fix the bottom mold relative to the guide rail;

[0011] The punch holder includes a sliding base mounted on the transverse support beam and a movable tool holder vertically guided on the sliding base. The sliding base has a transverse movement axis perpendicular to the guide rail, and the lower end of the movable tool holder is used to clamp the punch.

[0012] A fine-tuning mechanism, mounted on the sliding base, is used to drive the sliding base to linearly displace along the lateral movement axis;

[0013] A vertical drive mechanism is arranged on the sliding base, and its power output end is connected to the movable tool holder to provide a downward punching load to drive the punching operation.

[0014] Based on the initial coarse positioning of the punch holder, the fine-tuning mechanism drives the punch to perform lateral position compensation, thereby achieving spatial alignment between the punch cutting edge and the bottom die indentation groove.

[0015] Furthermore, the guide rail is a T-shaped groove or dovetail groove machined on the upper surface of the operating table, and the protruding structure is a T-shaped solid boss or dovetail solid boss that matches the internal contour of the guide rail. The starting end face of the guide rail is cut with a chamfered bevel that extends outward, and the chamfered bevels on the left and right sides are joined together to form a guide flared mouth with a gradually narrowing width.

[0016] When the bottom mold is pushed in, the chamfered surface generates a lateral force on the front end of the bottom mold, forcing the bottom mold to slide along the center line of the guide rail, thus achieving initial calibration of the lateral position of the bottom mold before entering the straight groove section.

[0017] Furthermore, a position reference datum is provided on the surface of the operating table parallel to the guide rail. The position reference datum is used to confirm the target working range of the bottom mold in the longitudinal direction of the guide rail. The position reference datum is a scale line provided along the side of the guide rail.

[0018] The longitudinal coordinates of the bottom mold are obtained by comparing the relative position of the bottom mold end face with the scale line to confirm that the bottom mold is stationary within the set working range.

[0019] Furthermore, the locking mechanism includes an external handle, an eccentric shaft, and an eccentric cam;

[0020] The external handle is connected to the eccentric rotating shaft, which passes through the vertical shaft hole reserved in the bottom mold. The eccentric cam is installed at the lower end of the eccentric rotating shaft and accommodated in the internal groove of the guide rail.

[0021] Rotating the external handle causes the eccentric cam to rotate around the eccentric shaft, causing the outer contour surface of the eccentric cam to press against the inner wall of the guide rail and output a horizontal lateral thrust.

[0022] Furthermore, the sidewall of the guide rail is an inclined plane, and the inclined side of the protruding structure, under the pressure of the horizontal lateral thrust, tends to slide downward along the inclined plane of the guide rail, converting the lateral thrust into a downward vertical clamping force.

[0023] The rise angle of the eccentric cam at the locking point is less than the equivalent static friction angle between the outer surface of the eccentric cam and the inner wall of the guide rail, thus forming an eccentric friction self-locking mechanism.

[0024] The horizontal force is converted into a vertical clamping force by utilizing the inclined plane wedge effect, and an anti-loosening mechanism is established based on the material friction characteristics and the cam eccentricity ratio to overcome the reverse force generated by the stamping vibration.

[0025] Furthermore, a scale parallel to the moving direction of the sliding base is fixedly installed on the upper part of the operating table, and the zero mark of the scale coincides with the central machining reference surface of the operating table; an indicator pointer that cooperates with the scale is fixed on the outer side of the sliding base to provide an initial lateral coarse positioning reference between the sliding base and the center surface of the bottom mold before fine adjustment.

[0026] Establish a mapping relationship between the installation position of the bottom mold and the scale reading, and control the initial spatial deviation of the upper and lower molds within the adjustment tolerance of the fine-tuning mechanism.

[0027] Furthermore, the sliding base is slidably mounted on the transverse support beam via a linear slider. The fine-tuning mechanism includes a fine-tuning screw, a fine-tuning nut, and a bearing assembly. The fine-tuning screw is rotatably mounted on the side of the sliding base. The bearing assembly is used to axially limit the fine-tuning screw relative to the sliding base. The threaded section of the fine-tuning screw meshes with the fine-tuning nut fixed on the transverse support beam. Rotating the fine-tuning screw converts the rotational motion into a linear translation of the sliding base along the transverse support beam.

[0028] The rotary motion at the input end is proportionally converted into the linear displacement of the punch holder by using a screw drive.

[0029] Furthermore, a fastening assembly is provided on the back side of the sliding base. The fastening assembly is used to lock the lateral sliding freedom of the sliding base. The fastening assembly includes a locking bolt that penetrates the body of the sliding base. The front end face of the locking bolt abuts against the sliding surface of the lateral support beam. When the locking bolt is tightened, it forces the internal guide surface of the sliding base to fit tightly against the lateral support beam, and the unidirectional force of the end face abutting reduces the reverse transmission gap between the fine adjustment screw and the fine adjustment nut.

[0030] The rigid locking sliding base reduces mechanical clearance while providing static friction to resist the lateral component of the stamping force.

[0031] Furthermore, the surface roughness of the operating table surface and the bottom surface of the bottom mold is configured to be between Ra1.6 and Ra3.2, and the bottom surface of the bottom mold is provided with an oil storage groove extending longitudinally to reduce sliding friction resistance.

[0032] Furthermore, the vertical drive mechanism includes a hydraulic cylinder, the hydraulic rod at the output end of the hydraulic cylinder being connected to the movable tool holder, for pushing the movable tool holder vertically downward to perform indentation forming and vertically returning to its original position after a single operation.

[0033] In summary, the present invention has at least one of the following beneficial technical effects:

[0034] 1. This invention achieves rapid insertion and rigid fixation of the bottom mold by setting a guide flare at the starting end of the guide rail and integrating an eccentric locking mechanism on the bottom mold. The guide flare provides a lateral force when the bottom mold is pushed in, calibrating the position of the bottom mold to prevent sliding and jamming. When the locking mechanism is working, the eccentric cam presses against the side wall of the guide rail, converting the horizontal lateral thrust into a vertical clamping force through the inclined wedge effect. It also utilizes the mechanical characteristic that the working helix angle is smaller than the static friction angle to form a friction self-locking mechanism, simplifying the installation and fastening process of the bottom mold. Furthermore, it can effectively overcome the loosening of the mechanism caused by stamping vibration by relying on the self-locking characteristic.

[0035] 2. This invention adopts a transmission structure that combines coarse positioning with screw fine adjustment, which improves the alignment accuracy of the upper and lower molds. The system completes the initial lateral coordinate mapping through the scale on the operating table and the pointer on the sliding base, controlling the spatial deviation within the fine adjustment tolerance. Then, the screw and nut transmission pair of the fine adjustment mechanism is used to convert the rotational motion of the input end into a small linear translation of the punch support according to the pitch ratio, so that the position compensation of the punch cutting edge and the bottom mold indentation groove has quantifiable adjustment accuracy, solving the problem of inaccurate alignment in traditional manual push and pull.

[0036] 3. The present invention configures a fastening component on the back side of the sliding base of the punch holder, which reduces the mechanical transmission clearance and locks the stamping operation position. After the upper and lower dies are precisely aligned, the operator tightens the locking bolt so that its front end face directly abuts against the sliding surface of the transverse support beam. The unidirectional pressure force forces the internal guide surface of the sliding base to fit tightly against the support beam, which not only reduces the reverse transmission clearance between the fine adjustment screw and the nut, but also generates sufficient static friction to resist the lateral component force generated when stamping the cardboard, thus maintaining the positional stability of the die during continuous operation. Attached Figure Description

[0037] Figure 1 This is a perspective view of the present invention;

[0038] Figure 2 This is a schematic diagram of the method flow of the present invention;

[0039] Figure 3 This is a schematic diagram of the complete main process of the present invention.

[0040] The components include: 1. Operating table; 2. Guide rail; 3. Bottom mold; 4. Locking mechanism; 5. Punch support; 6. Vertical drive mechanism; and 7. Fine-tuning mechanism. Detailed Implementation

[0041] See attached document Figure 1 The present invention provides a quick-change bottom mold system for a corrugated cardboard creasing machine, which may include: an operating table 1, a guide rail 2, a bottom mold 3, a locking mechanism 4, a punch support 5, a fine-tuning mechanism 7, and a vertical drive mechanism 6.

[0042] The operating table 1 forms the basic support surface of the creasing machine. Guide rails 2 are arranged on the upper surface of the operating table 1 along the feeding direction of the cardboard material. The guide rails 2 are machined into the metal base of the operating table 1, providing a linear guide trajectory for the installation of the bottom mold 3 and a position constraint interface.

[0043] The bottom mold 3 is slidably assembled within the guide rail 2. The bottom geometry of the bottom mold 3 matches the cross-sectional profile of the guide rail 2. The bottom mold 3 reciprocates linearly along the extension direction of the guide rail 2.

[0044] The locking mechanism 4 is integrated into the side wall or end of the bottom mold 3. The internal force-bearing end of the locking mechanism 4 contacts the side wall of the guide rail 2. After the bottom mold 3 moves to the target position, the locking mechanism 4 applies a lateral force to rigidly fix the bottom mold 3 relative to the guide rail 2.

[0045] The punch holder 5 is positioned above the operating table 1 and includes a sliding base mounted on a transverse support beam and a movable tool holder vertically guided on the sliding base. The transverse movement axis of the sliding base is perpendicular to the axis of the guide rail 2. The lower end of the movable tool holder holds the punch, and the upper and lower alignment of the punch and the bottom mold 3 is achieved by sliding and adjusting the position of the sliding base along the transverse axis.

[0046] The fine-tuning mechanism 7 is mounted on the sliding base. Through mechanical transmission components such as lead screw and nut, the fine-tuning mechanism 7 converts the rotational motion of the input end into a proportional linear displacement of the sliding base along the transverse axis. This is used to drive the punch to perform transverse position compensation based on the initial coarse positioning of the punch holder 5, thereby achieving high-precision spatial alignment between the punch cutting edge and the indentation groove of the bottom die 3.

[0047] The vertical drive mechanism 6 is arranged on the sliding base, and its power output end is connected to the movable knife holder to provide a vertically downward punching load to drive the punch to perform a creasing operation on the corrugated cardboard laid flat on the bottom mold 3.

[0048] See attached document Figure 2 This invention provides a quick-change bottom die method for a corrugated cardboard creasing machine, comprising the following steps:

[0049] S100, align the end of the bottom mold 3 with the opening of the guide rail 2 on the upper surface of the operating table 1;

[0050] S200, slide the protruding structure at the bottom of the bottom mold 3 into the guide rail 2, and push the bottom mold 3 to the set working range along the axial direction of the guide rail 2;

[0051] S300, rotate the external handle of the locking mechanism 4 to drive the internal cam to rotate and output a clamping force perpendicular to the inner wall of the guide rail 2, so that a friction self-locking connection is established between the bottom surface of the bottom mold 3 and the inner wall surface of the guide rail 2.

[0052] S400, with the center plane of the fixed bottom mold 3 as the reference, the sliding base of the horizontal sliding punch bracket 5 is roughly positioned by combining the scale attached to the edge of the operating table 1, so that the sliding base is initially aligned with the bottom mold 3.

[0053] S500 drives the punch to generate lateral compensation displacement through the fine adjustment mechanism 7 configured on the sliding base, so that the center of the punch blade edge is precisely aligned with the center of the indentation groove on the surface of the bottom mold 3. Then, the lateral sliding freedom of the sliding base is locked, and the vertical drive mechanism 6 arranged on the sliding base above is triggered to drive the movable knife holder and the punch downward to perform a punching operation on the corrugated cardboard.

[0054] See attached document Figure 3This invention provides a specific implementation method for aligning the end of the bottom mold 3 with the opening position of the guide rail 2 on the upper surface of the operating table 1, aiming to achieve smooth introduction of the bottom mold 3 through structural feature constraints, and includes the following specific sub-steps:

[0055] S101, the operator obtains the bottom mold 3 to be replaced and aligns the bottom protrusion of the bottom mold 3 horizontally with the starting end of the guide rail 2 on the edge of the operating table 1. The guide rail 2 is physically manifested as a parallel groove machined on the upper surface of the operating table 1.

[0056] Specifically, as one implementation, the cross-sectional shape of the guide rail 2 can be designed as a T-slot or a dovetail groove to provide limiting constraints perpendicular to the table surface. Correspondingly, the protruding structure at the bottom of the bottom mold 3 forms a T-shaped solid boss or a dovetail solid boss that matches the internal contour of the guide rail 2. In its natural placement state, the flat base surface at the bottom of the bottom mold 3 supports the upper surface of the operating table 1, and the sidewall of the protruding structure at the bottom of the bottom mold 3 forms a sliding guide fit with the inner sidewall of the guide rail 2, thereby allowing axial sliding while ensuring vertical limiting. The operating table 1 has multiple guide rails 2 of the same specifications arranged parallel to each other along the feed direction, giving the bottom mold 3 a physical basis for interchangeable installation between any two adjacent guide rails 2.

[0057] S102, push the bottom mold 3 closer to the center of the operating table 1, and use the mechanical guide surface at the end of the guide rail 2 for adaptive lateral position correction. In manual assembly operations, the initial placement position of the bottom mold 3 usually has a lateral offset. To address this, an outwardly extending chamfered surface is cut on the starting end face of the guide rail 2. The chamfered surfaces on the left and right sides are joined together to form a guide flared opening with a gradually narrowing width.

[0058] During the process of pushing in the bottom mold 3, if the central axis of the bottom mold 3 deviates from the central axis of the guide rail 2, the front corner of the protruding structure at the bottom of the bottom mold 3 will contact the chamfered slope first. When the longitudinal thrust is continued to be applied, the chamfered slope will generate a lateral component force on the front end of the bottom mold 3, forcing the bottom mold 3 to slide along the theoretical center line of the guide rail 2, thereby achieving preliminary calibration of the lateral position of the bottom mold 3 before entering the straight groove section.

[0059] S103, maintaining the horizontal pushing posture of the bottom mold 3, overcoming the initial end-face friction force to allow the bottom mold 3 to slide into the straight mating section of the guide rail 2. When the bottom mold 3 enters the straight section of the guide rail 2, there is a certain angle of tilt tolerance. Excessive deflection will cause the front and rear ends of the protruding structure at the bottom of the bottom mold 3 to simultaneously jam against the inner walls of both sides of the guide rail 2, triggering mechanical self-locking. To reduce the risk of jamming during the sliding introduction process, a conventional sliding clearance fit is used between the protruding structure at the bottom of the bottom mold 3 and the guide rail 2. Since the T-slot or dovetail groove guide rail 2 is a conventional structure with mature machining technology in the machine tool field, its anti-jamming capability directly depends on the reasonable configuration of the slot width clearance and the mating length. In specific physical implementation, by controlling the machining tolerance of the maximum horizontal width of the protruding structure at the end of the bottom mold 3 and the minimum width of the inner side of the guide rail 2, it has a small lateral movement allowance. At the same time, combined with the physical limiting effect of the guide bell mouth at the end of the guide rail 2, the horizontal deflection amplitude of the bottom mold 3 in the initial pushing stage is constrained within the allowable range. This mechanical constraint structure ensures that the front and rear sides of the bottom mold 3 will not form diagonal dead points that jam against the inner wall of the guide rail 2, thus ensuring the smooth advancement of the bottom mold 3 along a straight trajectory.

[0060] For the surface hardening process of guide rail 2 and the specific processing steps of guide chamfering, those skilled in the art can refer to the manufacturing specifications of standard machine tool worktables. The surface heat treatment methods are well-known technologies in this field and will not be elaborated here.

[0061] This invention provides a specific implementation method for advancing the bottom mold 3 along the guide rail 2 and confirming the target working area, which includes the following specific sub-steps:

[0062] S201, a thrust is applied along the extension direction of guide rail 2, driving the bottom mold 3 to slide linearly inside guide rail 2. The protruding structure at the bottom of the bottom mold 3 is clearance-fitted with the inner wall of guide rail 2. In the sliding assembly state, the flat reference surface at the bottom of the bottom mold 3 is in contact with the upper surface of the operating table 1, forming the main bearing surface that bears the weight of the bottom mold 3 itself and the subsequent stamping load. At the same time, the vertical sidewall of the protruding structure at the bottom of the bottom mold 3 forms a lateral limiting guide surface with the inner groove wall of guide rail 2. During the advancement process, the protruding structure at the bottom of the bottom mold 3 usually only plays a linear guiding role, avoiding bearing the vertical gravity load, thereby reducing the sliding jamming caused by the deformation of the protruding structure under pressure. To illustrate the resistance control principle during the sliding process, the resistance that the bottom mold 3 needs to overcome when moving mainly comes from the sliding friction between the bottom surface of the bottom mold 3 and the surface of the operating table 1. In a specific implementation, by controlling the surface roughness of the operating table 1 and the bottom surface of the mold 3 within the range required by conventional machine tool guideways, such as Ra1.6 to Ra3.2, the dynamic friction coefficient can be effectively reduced. Furthermore, an oil reservoir extending longitudinally can be opened on the bottom surface of the mold 3 to further reduce the sliding resistance between metal surfaces by utilizing the lubrication film effect, so that the horizontal thrust required to advance the mold 3 remains within the reasonable force range of conventional manual operation.

[0063] S202, based on the specifications and dimensions of the corrugated cardboard to be processed, the bottom mold 3 is continuously advanced to the target working area on the operating table 1. In one specific implementation, this working area physically corresponds to the actual feeding path of the corrugated cardboard within the equipment. To achieve precise positioning of this area, a position reference datum is set parallel to the guide rail 2 on the surface of the operating table 1. This position reference datum is represented by fixed scale lines engraved or printed along the side of the guide rail 2. By visually comparing the relative position of the end face of the bottom mold 3 with the scale lines, the operator can obtain the exact position of the bottom mold 3 in the longitudinal direction of the guide rail 2, thereby confirming that the bottom mold 3 accurately stops within the working area matching the current production specifications.

[0064] S203, stop applying horizontal thrust, allowing the bottom mold 3 to remain stationary within the target working area. At this point, the bottom mold 3 has completed its longitudinal positioning. Due to the mechanical sliding clearance between the protruding structure at the bottom of the bottom mold 3 and the guide rail 2, the bottom mold 3 in its current state typically retains a small degree of freedom of movement in the lateral direction perpendicular to the axis of the guide rail 2. This lateral movement allowance is the mechanical condition that ensures the bottom mold 3 can be smoothly pulled out and replaced along a straight line. The bottom mold 3 maintains a partially constrained lateral state at this stage, providing a physical basis for the subsequent intervention of the locking mechanism 4 and the establishment of a stable rigid fixation.

[0065] The calibration method for the scale lines on the surface of the operating table 1 and the lubrication process for reducing the friction coefficient of the mechanical contact surface can be conventionally configured by those skilled in the art according to the actual machine tool assembly accuracy standards. The surface calibration and basic lubrication methods are well-known technologies in the field and will not be elaborated here.

[0066] This invention provides a specific implementation method for establishing a frictional self-locking connection between the bottom mold 3 and the guide rail 2 through a locking mechanism 4, which includes the following specific sub-steps:

[0067] S301, the operator rotates the external handle of the locking mechanism 4, driving the cam assembly into the locking stroke. Specifically, in one embodiment, the locking mechanism 4 includes an external handle, an eccentric shaft, and an eccentric cam. The external handle is rigidly connected to the eccentric shaft, which passes through a pre-drilled vertical shaft hole in the body of the bottom mold 3. The eccentric cam is installed at the lower end of the eccentric shaft and accommodated in the internal cavity of the guide rail 2. When the external handle is rotated, the torque is transmitted to the eccentric cam through the vertical eccentric shaft, causing the eccentric cam to rotate around the geometric center of the eccentric shaft. Because there is an eccentricity between the center of curvature of the eccentric cam and the geometric center of the eccentric shaft, the rotation process causes the outer contour surface of the eccentric cam to gradually approach the inner wall of the guide rail 2 until it contacts the metal groove wall.

[0068] S302, the eccentric cam presses against the inner wall of guide rail 2, converting the lateral thrust into a vertical clamping force through the inclined plane wedge effect. As the eccentric cam continues to rotate, its highest point abuts against and presses against the inner wall of guide rail 2, generating a horizontal lateral thrust perpendicular to the axis of guide rail 2. Under the action of this horizontal lateral thrust, the bottom mold 3 consumes the transverse assembly clearance, causing the other side wall of the bottom protrusion structure of the bottom mold 3 to adhere tightly to the opposite inner wall of guide rail 2. In order to convert the lateral force into a downward fixing force, when the cross-section of guide rail 2 adopts a dovetail groove or a T-slot with a chamfer at the bottom, the side wall of guide rail 2 is an inclined plane. Under the pressure of the horizontal lateral thrust, the inclined side of the bottom mold 3 protrusion structure tends to wedge downward along the inclined plane of guide rail 2. According to the force distribution characteristics of the inclined plane, the inclined plane generates a normal reaction force on the bottom mold 3 protrusion structure. This normal reaction force can be decomposed into a horizontal reaction force resisting the eccentric cam and a downward vertical clamping force. The vertical clamping force forces the bottom surface of the bottom mold 3 to fit against the upper surface of the operating table 1, completing the transformation from horizontal force to multi-dimensional clamping force.

[0069] S303, to maintain the fixed state of the bottom mold 3 after the external operating force is removed, the system adopts eccentric friction self-locking. The anti-reverse self-locking effect of the eccentric cam depends on the matching of the cam's working helix angle and the friction characteristics of the contact surface material. In the specific structural design, by controlling the ratio of the eccentricity of the eccentric cam to the base circle radius, the helix angle of the eccentric cam at the locking working point is made smaller than the equivalent static friction angle between the outer surface of the cam and the inner wall of the guide rail 2. For example, in the case of conventional machine tool steel parts, the eccentricity of the eccentric cam can be set in the range of 1 to 3 mm to ensure that its maximum working helix angle does not exceed 5 degrees. At the same time, machining texture or micro-roughening treatment can be performed on the outer contact edge of the eccentric cam to maintain a stable static friction coefficient. Under the above geometric and surface constraints, when the equipment generates stamping vibration, the static friction force at the cam contact point can effectively overcome the reverse tangential sliding force that causes the mechanism to loosen, thereby preventing the locking mechanism 4 from loosening and maintaining the stable connection between the bottom mold 3 and the operating table 1.

[0070] For the CNC machining programming method of the outer contour curve of the eccentric cam and the selection of assembly tolerances for the shaft bearing assembly, those skilled in the art can make conventional adaptations based on the standard machine tool fixture design manual. The machining and basic assembly methods are well-known technologies in this field and will not be elaborated here.

[0071] This invention provides a specific implementation method for coarsely positioning the punch holder 5 laterally using a fixed bottom mold 3 as a reference, which includes the following specific sub-steps:

[0072] S401, Establish a mechanical reference datum for the coordination of the upper and lower molds. As one implementation, a scale is fixedly installed on the upper crossbeam of the operating table 1, parallel to the moving direction of the sliding base. To establish an alignment reference for the upper and lower molds, the zero mark of this scale coincides with the center machining reference plane of the operating table 1. Since the machining positions of each guide rail 2 on the operating table 1 are fixed, the central axis of each guide rail 2 corresponds to a known reference scale value in the direction of the aforementioned scale. Through this structural configuration, a mapping relationship is established between the installation position of the bottom mold 3 and the scale reading.

[0073] S402, Extract the reference coordinate values ​​of the fixed bottom mold 3. After the bottom mold 3 is self-locked and fixed within the specific guide rail 2, the position of its lateral center plane is determined. The operator can directly obtain the pre-calibrated reference scale value of the guide rail 2 according to the number of the current bottom mold 3, or observe the reading of the center mark line at the end of the bottom mold 3 on the bottom auxiliary scale, and use this value as the target position parameter for the subsequent lateral movement of the sliding base.

[0074] S403, the sliding base is driven to slide laterally to complete the initial alignment. The sliding base of the punch holder 5 is movably mounted on the transverse support beam above the operating table 1 via guide components such as linear sliders. The operator applies a lateral thrust to the sliding base, causing it to slide along the transverse support beam. Simultaneously, an indicator pointer that cooperates with the aforementioned scale is fixedly installed on the outer side of the sliding base. During the sliding process, the operator observes the scale reading indicated by the indicator pointer. When this reading substantially coincides with the target position parameter obtained in step S402, the thrust is stopped.

[0075] Considering the inherent limitations of manual visual reading, a certain degree of mechanical positional deviation is allowed during the initial alignment at this stage. Typically, limited by the width of the metal scale's graduations and the human eye's ability to discern details, this coarse positioning operation controls the lateral deviation between the sliding base and the center surface of the bottom mold 3 within the minimum scale division range, for example, between 0.5 and 1.0 mm. Within this tolerance range, the sliding base and the bottom mold 3 achieve initial vertical spatial alignment; any remaining positional deviation will be reduced by the subsequently configured fine-tuning mechanism 7.

[0076] For the laser engraving process of the scale and the straightness calibration method of the upper transverse support beam, those skilled in the art can perform conventional configuration according to standard machine tool assembly specifications. The manufacturing of the scale markings and the leveling of the guide rail 2 are well-known technologies in the field and will not be described in detail here.

[0077] This invention provides a specific implementation method for achieving high-precision alignment and locking of sliding degrees of freedom between the punch and the bottom die 3, comprising the following specific sub-steps:

[0078] S501, the operator rotates the input end of the fine-tuning mechanism 7, converting the rotational motion into a small lateral linear displacement of the sliding base. In one embodiment, a lead screw and nut transmission assembly is mounted on the sliding base. Specifically, the fine-tuning lead screw is rotatably mounted on the side of the sliding base in a direction parallel to the transverse support beam, and its axial positioning relative to the sliding base is achieved through a bearing assembly; the threaded section of the fine-tuning lead screw engages with a fine-tuning nut fixed on the transverse support beam. When the operator rotates the handwheel connected to the end of the fine-tuning lead screw, the lead screw is helically propelled within the fine-tuning nut. Because the fine-tuning lead screw is axially limited on the sliding base, this rotational motion is converted into a linear translation of the sliding base along the transverse support beam, thereby driving the punch held at the lower end to produce a lateral compensating displacement.

[0079] Based on the mechanical principle of screw drive, the lateral displacement generated by the sliding base depends on the thread pitch of the fine-tuning screw and the rotation angle of the handwheel. Specifically, for each complete rotation of the handwheel, the sliding base will shift laterally by an absolute distance equal to one thread pitch. Through this mechanical speed-reducing and force-increasing structure, the large rotational motion of the handwheel can be converted into a small and precise linear displacement by a defined reduction ratio. In actual equipment configurations, to meet high-precision adjustment requirements, the fine-tuning screw typically uses a fine-pitch thread, with a pitch range of 1.0–1.5 mm. Combined with the angular graduation lines engraved on the outer ring of the handwheel, the lateral compensation displacement can be precisely controlled within a micrometer-level adjustment range of 0.01–0.05 mm.

[0080] S502 utilizes fine-tuning displacement to reduce the tolerance left over from the initial alignment, achieving precise alignment of the upper and lower dies. Operators, using indentation tests or physical measuring tools such as die gauges, observe the relative position of the current punch blade edge and the indentation groove of the bottom die 3. Specifically, this can be determined by observing whether the punch blade edge is on the central symmetrical plane of the indentation groove, or by observing whether the indentation depth on both sides of the cardboard is consistent through an indentation test, to assess lateral deviation. Adjusting the direction of the fine-tuning handwheel according to the deviation direction drives the sliding base to perform bidirectional lateral micro-movements of the punch until the center plane of the punch blade edge precisely coincides with the center plane of the indentation groove on the surface of the bottom die 3. At this point, the punch blade edge and the indentation groove achieve high-precision coplanarity in physical space, fulfilling the geometric conditions for stamping corrugated cardboard.

[0081] S503, a rigid fixed sliding base, reduces the fine-tuning transmission clearance and locks the lateral sliding degree of freedom. After completing the centering fine-tuning, the sliding base needs to be locked to resist the high-frequency lateral impact force generated by subsequent stamping operations. In physical implementation, the locking of the lateral sliding degree of freedom of the sliding base is usually achieved by a fastening assembly configured on the back side of the sliding base. Specifically, the fastening assembly can be a locking bolt that penetrates the body of the sliding base, with the front end face of the locking bolt abutting against the sliding surface of the transverse support beam. The operator uses a tool to tighten the locking bolt, and the front end of the bolt applies vertical pressure to the transverse support beam. This pressure forces the internal guide surface of the sliding base to fit tightly against the transverse support beam. At the same time, this rigid clamping based on the end face abutting also reduces the reverse transmission clearance between the fine-tuning screw and the fine-tuning nut through unidirectional force, thereby effectively maintaining the lateral position stability of the punch during the indentation operation.

[0082] After the sliding base completes the aforementioned high-precision lateral alignment and rigid locking, the equipment possesses the geometric conditions for stamping corrugated cardboard and then enters the stamping execution stage. The corrugated cardboard to be processed is conveyed along the feed direction and laid flat on the surface of the bottom mold 3. The system control command triggers the vertical drive mechanism 6, such as a hydraulic cylinder, arranged above on the sliding base. The hydraulic cylinder drives the hydraulic rod at its output end to extend downward in a straight line, pushing the movable cutter holder to carry the punch vertically downward. As the punch presses down, the cutting edge contacts the corrugated cardboard and presses a portion of its material into the indentation groove on the surface of the bottom mold 3. During this stamping process, the sliding base, with its locked rigidity, effectively resists the lateral force generated by the deformation of the cardboard and provides stable vertical guidance for the movable cutter holder, ensuring that the relative center position of the cutting edge and the indentation groove does not shift. After completing a single indentation, the hydraulic rod drives the movable cutter holder to return vertically to its original position, releasing the cardboard and waiting for the next operation.

[0083] For the backlash compensation structure of the lead screw transmission pair, the wear-resistant treatment process of the thread surface, and the basic control logic of the vertical drive mechanism 6, those skilled in the art can refer to the standard precision mechanical design manual for routine assembly. The reduction of mechanical backlash, anti-loosening fastening, and hydraulic reciprocating stroke control methods are well-known technologies in the field and will not be elaborated here.

Claims

1. A modular quick-change bottom die system for a corrugated cardboard creasing machine, characterized in that, include: The operating table (1) has a guide rail (2) arranged on its upper surface along the paperboard feeding direction, and a transverse support beam is provided above the operating table (1). The bottom mold (3) is assembled inside the guide rail (2). The bottom protrusion structure of the bottom mold (3) matches the cross section of the guide rail (2). The surface of the bottom mold (3) is provided with an indentation groove. The bottom mold (3) moves linearly along the guide rail (2). A locking mechanism (4) is provided on the bottom mold (3) for applying lateral force to fix the bottom mold (3) relative to the guide rail (2); The punch holder (5) includes a sliding base mounted on the transverse support beam and a movable tool holder vertically guided on the sliding base. The sliding base has a transverse movement axis perpendicular to the guide rail (2), and the lower end of the movable tool holder is used to clamp the punch. Fine-tuning mechanism (7) is installed on the sliding base and is used to drive the sliding base to linearly move along the transverse axis; A vertical drive mechanism (6) is arranged on the sliding base, and its power output end is connected to the movable tool holder to provide a downward punching load to drive the punching operation.

2. The modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The guide rail (2) is a T-shaped groove or dovetail groove machined on the upper surface of the operating table (1). The protruding structure is a T-shaped solid boss or dovetail solid boss that matches the internal contour of the guide rail (2). The starting end face of the guide rail (2) is cut with a chamfered bevel that extends outward. The chamfered bevels on the left and right sides are joined together to form a guide flared mouth with gradually narrowing width.

3. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The operating table (1) has a position reference datum parallel to the guide rail (2) on its surface. The position reference datum is used to confirm the target working range of the bottom mold (3) in the longitudinal direction of the guide rail (2). The position reference datum is a scale line set along the side of the guide rail (2).

4. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The locking mechanism (4) includes an external handle, an eccentric shaft, and an eccentric cam; The external handle is connected to the eccentric rotating shaft, which passes through the vertical shaft hole reserved in the bottom mold (3). The eccentric cam is installed at the lower end of the eccentric rotating shaft and accommodated in the internal groove of the guide rail (2). Rotating the external handle can drive the eccentric cam to rotate around the eccentric shaft, causing the outer contour surface of the eccentric cam to press against the inner wall of the guide rail (2) and output a horizontal lateral thrust.

5. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 4, characterized in that, The sidewall of the guide rail (2) is an inclined plane. Under the pressure of the horizontal lateral thrust, the inclined side of the protruding structure will slide downward along the inclined plane of the guide rail (2), converting the lateral thrust into a downward vertical clamping force. The rise angle of the eccentric cam at the locking point is less than the equivalent static friction angle between the outer surface of the eccentric cam and the inner wall of the guide rail (2), thus forming an eccentric friction self-locking mechanism.

6. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, A scale parallel to the moving direction of the sliding base is fixedly installed on the upper part of the operating table (1), and the zero mark of the scale coincides with the central machining reference surface of the operating table (1). The sliding base is fixed with an indicator pointer that cooperates with the scale, which is used to provide an initial lateral coarse positioning reference between the sliding base and the center surface of the bottom mold (3) before fine adjustment.

7. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The sliding base is slidably mounted on the transverse support beam via a linear slider. The fine-tuning mechanism (7) includes a fine-tuning screw, a fine-tuning nut, and a bearing assembly. The fine-tuning screw is rotatably mounted on the side of the sliding base. The bearing assembly is used to axially limit the fine-tuning screw relative to the sliding base. The threaded section of the fine-tuning screw meshes with the fine-tuning nut fixed on the transverse support beam. Rotating the fine-tuning screw converts the rotational motion into a linear translation of the sliding base along the transverse support beam.

8. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 7, characterized in that, A fastening assembly is provided on the back side of the sliding base. The fastening assembly is used to lock the lateral sliding freedom of the sliding base. The fastening assembly includes a locking bolt that penetrates the body of the sliding base. The front end face of the locking bolt abuts against the sliding surface of the lateral support beam. When the locking bolt is tightened, it forces the internal guide surface of the sliding base to fit tightly against the lateral support beam. The unidirectional force of the end face abutting reduces the reverse transmission gap between the fine adjustment screw and the fine adjustment nut.

9. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The surface roughness of the operating table (1) and the bottom surface of the bottom mold (3) is configured to be between Ra1.6 and Ra3.

2. The bottom surface of the bottom mold (3) is provided with an oil storage groove extending longitudinally to reduce sliding friction resistance.

10. A modular quick-change bottom die system for a corrugated cardboard creasing machine according to claim 1, characterized in that, The vertical drive mechanism (6) includes a hydraulic cylinder, the hydraulic rod at the output end of the hydraulic cylinder is connected to the movable tool holder, and is used to push the movable tool holder vertically downward to perform indentation forming and vertically return to reset after a single operation.

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