Open-close mold cam with locking protection in multi-cavity bottle blowing machine and multi-cavity bottle blowing machine

Abstract

This invention discloses an opening and closing mold cam with locking protection in a multi-cavity blow molding machine, and the multi-cavity blow molding machine itself. A fixed trajectory cam groove is formed between an outer cam and an inner cam on the base. The inner cam breaks off in the mold closing area, and its tail has a mounting groove between it and the base. The head of a movable cam is inserted into and hinged in the mounting groove, and a mold closing cam groove is formed between the movable cam profile and the outer cam. A first elastic reset mechanism is provided on the base. A rest section cam profile is provided at the tail of the outer cam. The head of an auxiliary cam is hinged to the tail of the inner cam, and a locking auxiliary cam groove is formed between the auxiliary cam profile and the rest section cam profile. A second elastic reset mechanism is provided on the base. The above solution has advantages such as compact structure, effective handling of blank jamming problems, locking protection function, and low probability of locking abnormalities. The operational stability and production efficiency of the multi-cavity blow molding machine using the above solution are ensured and improved.

Description

Technical Field

[0001] This invention relates to the field of multi-cavity blow molding machine equipment, and more particularly to an opening and closing mold cam with locking protection in a multi-cavity blow molding machine and a multi-cavity blow molding machine. Background Technology

[0002] Plastic hollow containers are widely used in the beverage, pharmaceutical, cosmetic, food, and chemical industries due to their lightweight, low cost, and good safety. The equipment used to manufacture plastic hollow containers is typically a blow molding machine. A blow molding machine is a device that uses a blow molding process to transform plastic preforms—such as bottle preforms—into hollow containers—such as bottles. Its production efficiency mainly depends on factors such as the blow molding machine's rotation speed, the number of mold frame components, and the performance of the heating and cooling systems.

[0003] For a blow molding machine, several mold frame assemblies are typically arranged in a circular, evenly spaced pattern. Each mold frame assembly contains a left and right mold that can be opened and closed, a rocker arm roller that controls the opening and closing of the left and right molds, a locking shaft that unlocks or locks the left and right molds in the closed state, and an opening and closing roller that controls the locking shaft's unlocking and locking action. After the left and right molds are closed, their inner cavities form a mold cavity for blow molding. During operation, the rocker arm rollers at the bottom of each mold frame assembly run under the guidance of the opening and closing cam groove trajectory of the opening and closing cam in the blow molding machine, thereby enabling the left and right molds to complete the opening or closing action. The opening and closing rollers on each mold frame assembly run under the guidance of the opening and closing cam trajectory of the opening and closing cam in the blow molding machine, thereby enabling the locking shaft to unlock or lock the left and right molds in the closed state. Typically, the opening and closing cam is located outside the opening and closing cam.

[0004] During the operation of the blow molding machine, all mold frame components always move along a circumferential trajectory. The following description uses one mold frame component as an example to illustrate the opening and closing, and locking / unlocking processes. For ease of description, we assume the unlocking process after blow molding is completed. At this point, the locking / unlocking roller enters the locking / unlocking cam and moves along the unlocking section of the cam's trajectory. The locking / unlocking roller controls the locking shaft on the mold frame component to rotate until the left and right molds, which are in the closed state, are in the unlocked state. Next, the rocker arm roller moves along the opening section of the opening / unlocking cam groove in the mold opening / unlocking cam cam's trajectory. The mold opening / unlocking cam groove trajectory is typically the contour shape of the groove sidewall. The rocker arm roller causes the left mold, The right mold opens; when the left and right molds open to a certain extent, the bottle feeding robot removes the blown bottle from the mold cavity of the mold frame assembly and sends it away. Then, the preform picking robot sends the preform to be blown into the mold cavity. The swing arm roller runs in the mold closing area section of the mold opening and closing cam groove trajectory, so that the left and right molds close. When the left and right molds are closed, the opening and closing locking roller will enter the locking area section of the opening and closing locking cam trajectory and control the locking shaft on the mold frame assembly in the mold closing state to rotate until locking is completed. Then the mold frame assembly continues to run until the preform is blown. After blowing is completed, the above actions are repeated. In practical work, when the mold frame assembly enters the locking process after mold closing, in order to ensure that the locking operation of the mold frame assembly by the locking rollers and locking cams is stable and reliable, a resting section that matches the locking section of the locking cam is usually connected after the mold closing section of the locking cam. In this way, when the locking rollers are running in the locking section, the rocker arm rollers are running in the resting section, thus providing auxiliary protection for the locking operation of the mold frame assembly and greatly reducing the probability of abnormal locking operation.

[0005] In the operation of a conventional blow molding machine, when a preform feeding robot encounters an abnormality and a preform jamming occurs during the feeding process into the mold cavity of a mold frame assembly, the swing arm roller of that assembly cannot return to its normal position during mold closing. Consequently, the swing arm roller cannot operate normally in the mold closing section of the mold opening / closing cam groove. To solve this problem caused by preform jamming, conventional blow molding machines typically include a fixed-track cam and a movable cam. Specifically, a movable cam is installed in the mold closing section of the mold opening / closing cam. When a preform jamming occurs in a mold frame assembly during feeding, the abnormally positioned swing arm roller in the mold closing section pushes the movable cam, causing it to reposition and avoid damage. This ensures the abnormal swing arm roller can pass through the mold closing section without damage. After passing the movable cam, it promptly resets, ensuring that the swing arm rollers in other mold frame assemblies can perform normal mold closing operations.

[0006] To further improve the production efficiency of blow molding machines, a multi-cavity blow molding machine has been developed. Multi-cavity blow molding machines typically have more than 24 cavities, with common configurations including 26, 28, 32, and 36 cavities. In multi-cavity blow molding machines, the mold frame components are usually arranged in a circular, evenly spaced pattern. However, in multi-cavity blow molding machines, due to the smaller distance between adjacent mold frame components—often referred to as a smaller angle between two mold cavities—if a large-angle movable cam with a long mold closing trajectory is used in the mold opening and closing cam, during operation, swing arm rollers belonging to two or more mold cavities will simultaneously enter the movable cam area. When the mold frame component corresponding to the swing arm roller of the preceding mold cavity experiences a blank jamming abnormality, the preceding swing arm roller will push the movable cam to rotate and reposition to avoid it. This excessive rotation and repositioning of the movable cam, after avoiding the jamming, causes mold frame components corresponding to other swing arm rollers located within the movable cam to experience mold closing abnormalities. If the mold opening and closing cam uses a small-angle movable cam with a short mold closing trajectory, that is, only one mold cavity is allowed to enter the movable cam at a time during operation, although the mold frame assembly corresponding to the movable cam experiencing a blank jamming abnormality will not affect the normal mold closing of the subsequent mold frame assembly, the rest area of ​​the mold opening and closing cam is either too short or completely absent due to the small angle. This results in insufficient or no locking protection when the mold frame assembly enters the locking operation after mold closing, which will greatly increase the probability of locking abnormality. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a compact, flexible, and reliable multi-cavity blow molding machine with a locking protection cam. This cam effectively handles abnormal blank jamming and provides protection for the locking operation of the mold frame assembly, reducing the probability of locking anomalies. This invention also provides a multi-cavity blow molding machine equipped with the aforementioned opening and closing cam.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: the opening and closing mold cam with locking protection in the multi-cavity blow molding machine includes: a base, on which a fixed trajectory cam is provided, the fixed trajectory cam being composed of an outer cam and an inner cam, the inner sidewall cam profile of the outer cam and the outer sidewall cam profile of the inner cam forming a fixed trajectory cam groove that limits the running trajectory of the swing arm roller, the inner cam being disconnected in the mold closing area, and the bottom surface of the tail of the inner cam having an installation groove between it and the base; the head of the movable cam component being inserted into the installation groove and hinged in the installation groove; the movable cam component having a movable cam profile, the movable cam profile and the inner sidewall cam profile of the outer cam forming a mold closing cam groove that limits the running trajectory of the swing arm roller to enable the mold frame assembly to close normally, the mold closing cam groove being connected to the fixed trajectory cam groove, and the length of the mold closing cam groove during operation not allowing the swing arm rollers of two or more mold frame assemblies to enter the mold closing cam groove simultaneously; A first elastic reset mechanism is provided on the base to enable the movable cam component to reset normally and maintain the normal mold closing cam groove trajectory. When the mold frame assembly experiences a blank jamming abnormality during operation, the rocker arm roller can push the movable cam component to overcome the elastic force of the first elastic reset mechanism, causing the movable cam component to rotate around the hinge and displace to avoid the jamming. This allows the abnormal rocker arm roller to pass smoothly through the abnormal mold closing cam groove area formed by the displacement of the movable cam component. This reduces the probability of collisions of related parts and downtime for maintenance. After the abnormal rocker arm roller passes, the movable cam component can be reset in time under the action of the first elastic reset mechanism to restore the normal mold closing cam groove trajectory.

[0009] The outer cam, corresponding to the locking section of the opening and closing cam in the multi-cavity blow molding machine, has a rest section cam profile at its tail. An auxiliary cam is also provided, with its head hinged to the tail of the inner cam. The auxiliary cam has an auxiliary cam profile, and a locking auxiliary cam groove is formed between the auxiliary cam profile and the rest section cam profile to limit the running trajectory of the rocker arm roller and provide protection for the locking operation of the mold frame assembly. The locking auxiliary cam groove is connected to the mold closing cam groove. At this point, the following are connected sequentially from front to back: fixed trajectory cam groove, mold closing cam groove of the mold closing area, and locking auxiliary cam groove corresponding to the locking area.

[0010] A second elastic reset mechanism is provided on the base to enable the auxiliary cam to reset normally and maintain the normal locking auxiliary cam groove trajectory. When the die frame assembly experiences a blank jamming abnormality during operation, the rocker arm roller can push the auxiliary cam to overcome the elastic force of the second elastic reset mechanism, causing the auxiliary cam to rotate and displace around the hinge to avoid the jamming. This allows the abnormal rocker arm roller to pass smoothly through the abnormal locking auxiliary cam groove area formed by the displacement of the auxiliary cam. This reduces the probability of collisions of related parts and downtime for maintenance. After the abnormal rocker arm roller passes, the auxiliary cam can be reset in time under the action of the second elastic reset mechanism to restore the normal locking auxiliary cam groove trajectory.

[0011] Furthermore, in the aforementioned multi-cavity blow molding machine with locking protection for the mold opening and closing cam, the structure of the first elastic reset mechanism is as follows: an adjustment groove is provided on the base, the top of the adjustment shaft passes through the adjustment groove and is fixedly connected to the movable cam component, and a power source that can drive the adjustment shaft to rotate and reset the movable cam component around the hinge of the head of the movable cam component is provided between the base and the adjustment shaft extending out of the base.

[0012] Furthermore, in the aforementioned multi-cavity blow molding machine, the mold opening and closing cam with locking protection is powered by a cylinder hinged to the base, with the piston rod end of the cylinder hinged to the bottom of the adjusting shaft. During operation, the movement of the cylinder piston rod causes the movable cam to rotate and reset.

[0013] Furthermore, in the aforementioned multi-cavity blow molding machine, the mold opening and closing cam with locking protection includes a movable cam component comprising: a transition connecting seat and a movable cam, the movable cam being fixed to the top of the transition connecting seat; the front end of the transition connecting seat extending beyond the front end of the movable cam, and the head of the transition connecting seat extending into the mounting groove and hinged therein; the movable cam being located outside the mounting groove, and the contour of the movable cam being located on the outer side wall of the movable cam; a first limiting mechanism is also provided to limit the reset position of the movable cam component, thereby enabling the movable cam component to be better reset in the correct position.

[0014] Furthermore, in the aforementioned multi-cavity blow molding machine with a locking protection mold opening and closing cam, the outer side wall of the tail of the transition connecting seat is recessed inward to avoid obstructing the operation of the swing arm roller. The structure of the first limiting mechanism is as follows: the outer side wall of the tail of the transition connecting seat is recessed inward to avoid obstructing the operation of the swing arm roller. A first limiting block is fixedly installed on the base located outside the tail of the transition connecting seat. The position of the first limiting block is such that when the movable cam rotates around the hinge of the head of the movable cam towards the first limiting block and resets until the limiting surface abuts against the first limiting block, it is blocked by the first limiting block and cannot continue to rotate in that direction.

[0015] Furthermore, in the aforementioned multi-cavity blow molding machine, the mold opening and closing cam with locking protection has an auxiliary cam located above the movable cam component. The structure of the second elastic reset mechanism is as follows: a first connecting seat is fixedly installed on the auxiliary cam, and a second connecting seat is fixed to the base by a bracket. A reset power mechanism that allows the auxiliary cam to rotate and reset around its hinge is provided between the first and second connecting seats. A second limiting mechanism that can limit the reset position of the auxiliary cam is also provided, so that the auxiliary cam can be reset to the correct position more effectively.

[0016] The structure of the reset power mechanism is as follows: one end of the guide shaft is fixed on the first connecting seat, and the other end of the guide shaft extends into the connecting hole of the second connecting seat; a reset spring is fitted on the guide shaft, and the two ends of the reset spring abut against the first connecting seat and the second connecting seat respectively. The auxiliary cam can compress the reset spring under the action of external force to make the first connecting seat move closer to the second connecting seat. After the action of external force disappears, the elastic force of the reset spring will make the first connecting seat move away from the second connecting seat, thereby driving the auxiliary cam to rotate and reset. Alternatively, the structure of the reset power mechanism is as follows: one end of the guide shaft is fixed to the second connecting seat, and the other end of the guide shaft extends into the connecting hole of the first connecting seat; a reset spring is fitted on the guide shaft, and the two ends of the reset spring abut against the first connecting seat and the second connecting seat respectively. The auxiliary cam can compress the reset spring under the action of external force to make the first connecting seat move closer to the second connecting seat. After the action of external force disappears, the elastic force of the reset spring will make the first connecting seat move away from the second connecting seat, thereby driving the auxiliary cam to rotate and reset.

[0017] Furthermore, in the aforementioned multi-cavity blow molding machine with locking protection for the mold opening and closing cam, the structure of the second limiting mechanism is as follows: a second limiting block is fixedly provided on the inner cam located on the inner side of the front part of the auxiliary cam. The position of the second limiting block is such that when the auxiliary cam rotates and resets around the hinge point of the auxiliary cam head towards the second limiting block, it is blocked by the second limiting block and cannot continue to rotate in that direction.

[0018] Furthermore, in the aforementioned multi-cavity blow molding machine, the opening and closing mold cam with locking protection, wherein the hinge shaft of the head of the movable cam is hinged in the mounting groove and the hinge shaft of the head of the auxiliary cam is hinged to the tail of the inner cam, sharing the same hinge shaft.

[0019] Furthermore, in the aforementioned multi-cavity blow molding machine, the mold opening and closing cam with locking protection has a wear-resistant support block between the movable cam and the auxiliary cam to improve the overall stability of the device.

[0020] To achieve another objective of the present invention, the present invention also provides a multi-cavity blow molding machine, wherein the multi-cavity blow molding machine has an opening and closing mold cam with locking protection of any of the structures described above.

[0021] The beneficial effects of this invention are as follows: The mold opening and closing cam of this invention, comprising a small-angle movable cam and an auxiliary cam, operates flexibly and reliably during operation. It effectively addresses blank jamming issues and provides protection for the locking operation of the mold frame assembly, reducing the probability of locking anomalies. In particular, the double-layer design of the movable cam and the auxiliary cam stacked on top of each other further enhances the overall compactness of the structure, significantly saving installation space. The multi-cavity blow molding machine employing the mold opening and closing cam of this invention greatly improves the stability of equipment operation, thereby further ensuring and increasing the production capacity efficiency of the multi-cavity blow molding machine. Attached Figure Description

[0022] Figure 1 This is a three-dimensional structural diagram of the mold opening and closing cam with locking protection in the multi-cavity blow molding machine of the present invention.

[0023] Figure 2 yes Figure 1 A partially enlarged structural diagram.

[0024] Figure 3 yes Figure 1 A schematic diagram of the structure from a top-down view.

[0025] Figure 4 yes Figure 3 A partially enlarged structural diagram.

[0026] Figure 5 yes Figure 4 A schematic diagram of the structure of the movable cam after it swings inward at a certain angle.

[0027] Figure 6 This is a schematic diagram of the transition connector.

[0028] Figure 7 This is a schematic diagram of the movable cam.

[0029] Figure 8 This is a schematic diagram of the auxiliary cam.

[0030] Figure 9 yes Figure 3 A schematic diagram of the structure in the AA section.

[0031] Among them, the appendix Figure 1 To be continued Figure 9 Figure label explanation: 1. Base; 11. First protrusion; 12. Second protrusion; 13. Support; 14. Cam groove; 15. Mounting groove; 16. Mold closing cam groove; 17. First limit block; 18. Locking auxiliary cam groove; 19. Second limit block; 110. Adjustment groove; 2. Outer cam; 21. Inner wall cam profile; 22. Rest section cam profile; 3. Inner cam; 31. Outer wall cam profile; 4. Movable cam component; 41. Transition connecting seat; 42. Movable cam; 43. Movable cam profile; 44. Limiting surface; 45. First clearance surface; 46. Second clearance surface; 5. Adjusting shaft; 51. Cylinder; 6. Auxiliary cam; 61. Auxiliary cam profile; 62. Third clearance surface; 7. Hinge shaft; 8. First connecting seat; 9. Second connecting seat; 91. Bracket; 10. Swing arm roller; 101. Guide shaft; 102. Return spring. Detailed Implementation

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments.

[0033] Exemplary embodiments will be described more fully below with reference to the accompanying drawings; however, these exemplary embodiments may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will enable those skilled in the art to fully understand the scope of this disclosure.

[0034] In this embodiment, the multi-cavity blow molding machine features an opening and closing mold cam with locking protection, such as... Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the system includes: a base 1, on which a fixed-track cam is provided. The fixed-track cam consists of an outer cam 2 and an inner cam 3. A fixed-track cam groove 14, which defines the running trajectory of the rocker arm roller 10, is formed between the inner sidewall cam profile 21 of the outer cam 2 and the outer sidewall cam profile 31 of the inner cam 3. In actual operation, considering factors such as processing cost and assembly space control, the optimal solution is to provide an upwardly protruding first ridge 11 and a second ridge 12 on the base 1. The outer cam 2 is fixed to the first ridge 11, and the inner cam 3 is fixed to the second ridge 12, thereby raising the outer cam 2 and the inner cam 3. In addition, to facilitate the installation of the base 1, a support 13 can be provided at the bottom of the base 1.

[0035] The inner cam 3 breaks off in the mold closing area, and the second protrusion 12 also breaks off in the mold closing area. The second protrusion 12 breaks off earlier than the inner cam 3. That is to say, the tail of the inner cam 3 extends backward beyond the tail of the second protrusion 12, thus forming a recessed mounting groove 15 between the bottom surface of the tail of the inner cam 3 and the base 1.

[0036] The head of the movable cam 4 is inserted into the mounting groove 15 and hinged in the mounting groove 15. The movable cam 4 has a movable cam profile 43. The movable cam profile 43 and the inner sidewall cam profile 21 of the outer cam 2 form a mold closing cam groove 16 that limits the running trajectory of the rocker arm roller 10 so that the mold frame assembly can close the mold normally. The mold closing cam groove 16 is connected to the fixed trajectory cam groove 14. The length of the mold closing cam groove 16 is such that during operation, it does not allow the rocker arm roller 10 of two or more mold frame assemblies to enter the mold closing cam groove 16 at the same time. That is to say, during operation, the length of the mold closing cam groove 16 ensures that only one rocker arm roller 10 of the mold frame assembly can enter the mold closing cam groove 16 to perform mold closing work at any time.

[0037] Among them, the movable cam component 4 can be a single-piece swinging component, but considering factors such as manufacturing, the movable cam component 4 is designed as a combined swinging component consisting of a transition connecting seat 41 and a movable cam 42, such as... Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the movable cam 42 is fixed to the top of the transition connecting seat 41. The front end of the transition connecting seat 41 extends beyond the front end of the movable cam 42. The head of the movable cam member 4, which extends into and is hinged in the mounting groove 15, refers to the head of the transition connecting seat 41. The head of the transition connecting seat 41 extends into and is hinged in the mounting groove 15, while the movable cam 42 is located outside the mounting groove 15. When the movable cam member 4 swings, the movable cam 42 will not collide with the inner cam 3. The movable cam profile 43, which is provided on the movable cam member 4, is provided on the outer wall of the movable cam 42.

[0038] A first elastic reset mechanism is provided on the base 1 to enable the movable cam 4 to reset normally and maintain the normal mold closing cam groove trajectory. When the mold frame assembly experiences a blank jamming abnormality during operation, the swing arm roller 10 can push the movable cam 4 to overcome the elastic force of the first elastic reset mechanism, causing the movable cam 4 to rotate around the hinge and displace to avoid the jamming. This allows the abnormal swing arm roller 10 to pass smoothly through the abnormal mold closing cam groove area formed by the displacement of the movable cam 4, thus reducing the probability of collisions of related parts and downtime for maintenance. After the abnormal swing arm roller 10 passes, the movable cam 4 can be reset in time under the action of the first elastic reset mechanism to restore the normal mold closing cam groove trajectory.

[0039] like Figure 2 and Figure 9As shown, in this embodiment, the structure of the first elastic reset mechanism is as follows: an adjustment groove 110 is provided on the base 1, the top of the adjustment shaft 5 passes through the adjustment groove 110 and is fixedly connected to the movable cam 4, and a power source for driving the adjustment shaft 5 to rotate the movable cam 4 around the hinge of the head of the movable cam 4 and reset is provided between the base 1 and the adjustment shaft 5 extending out of the base 1.

[0040] The power source can be a cylinder 51, a spring, etc. This embodiment uses a cylinder 51 as an example. A cylinder 51 is hinged to the base 1, and the piston rod end of the cylinder 51 is hinged to the bottom of the adjusting shaft 5. During operation, when the swing arm roller 10, which is abnormally stuck, pushes the movable cam 4 to rotate inward around its hinge point, the piston rod of the cylinder 51 will extend outward. (See [reference]). Figure 5 As shown.

[0041] like Figure 4 , Figure 5 and Figure 6 As shown, in this embodiment, a first limiting mechanism is also provided to limit the reset position of the movable cam 4, so that the movable cam 4 can be reset to the correct position better. In this embodiment, the outer side wall of the tail of the transition connecting seat 41 is recessed inward to avoid obstructing the operation of the rocker arm roller 10. The structure of the first limiting mechanism is as follows: the outer side wall of the tail of the transition connecting seat 41 is recessed inward to form a limiting surface 44, and a first limiting block 17 is fixedly provided on the base 1 located outside the tail of the transition connecting seat 41. In normal working condition, the piston rod of the cylinder 51 is in the inward retracted state. During the retraction of the piston rod, it will push the tail of the movable cam 4 to rotate around the hinge of the head of the movable cam 4 towards the first limiting block 17, until the limiting surface 44 abuts against the first limiting block 17 and is blocked by the first limiting block 17 and cannot continue to rotate in that direction. Figure 4 The diagram shows the state when the piston rod retracts inward and the limiting surface 44 abuts against the first limiting block 17. In this state, the reset position of the movable cam component 4 is the position where the movable cam profile 43 on the movable cam component 4 is in the normal mold closing cam groove trajectory, which is the position where the mold frame assembly can close the mold normally.

[0042] To avoid interference, such as Figure 7 and Figure 8 As shown, the outer side wall of the tail of the movable cam 42 also extends inward to form a first clearance surface 45. The first clearance surface 45 will never contact the first limiting block 17 during the swinging process of the movable cam 4. The remaining part of the outer side wall of the transition connecting seat 41, excluding the limiting surface 44, is the second clearance surface 46. The second clearance surface 46 does not extend beyond the outer side of the movable cam 42, thus ensuring that the rocker arm roller 10 contacts the movable cam profile 43 after entering the mold closing cam groove 16, but does not contact the second clearance surface 46.

[0043] During operation, if a blank feeding malfunction by the robotic arm causes a blank jam in a mold frame component, the swing arm roller 10 on that component will not return to its normal position. In this case, the malfunctioning swing arm roller 10 can push the movable cam 4 to reposition and avoid the malfunction, so that the width of the mold closing cam groove 16 where the swing arm roller 10 passes can be suitable for the passage of the malfunctioning swing arm roller 10. This allows the malfunctioning swing arm roller 10 to pass smoothly through the abnormal mold closing cam groove area formed by the repositioning of the movable cam 4, thus reducing the probability of collisions between related parts and downtime for maintenance. After the malfunctioning swing arm roller 10 successfully passes through the abnormal mold closing cam groove area caused by the repositioning of the movable cam 4, the movable cam 4 can be reset in time under the action of the first elastic reset mechanism, so as not to affect the normal mold closing operation of the mold frame components that follow.

[0044] In this embodiment, the tail of the outer cam 2, which corresponds to the locking area of ​​the opening and closing cam in the multi-cavity blow molding machine, is provided with a rest section cam profile 22; an auxiliary cam 6 is also provided, the head of the auxiliary cam 6 is hinged to the tail of the inner cam 3, the auxiliary cam 6 has an auxiliary cam profile 61, and a locking auxiliary cam groove 18 is formed between the auxiliary cam profile 61 and the rest section cam profile 22 to limit the running trajectory of the swing arm roller to provide protection for the locking operation of the mold frame assembly. The locking auxiliary cam groove 18 is connected to the mold closing cam groove 16.

[0045] A more preferred embodiment is that the hinge shaft at which the head of the movable cam 4 is hinged in the mounting groove 15 and the hinge shaft at which the head of the auxiliary cam 6 is hinged to the tail of the inner cam 3 share the same hinge shaft 7. This arrangement also makes the overall structure more compact and facilitates installation.

[0046] In this embodiment, a second elastic reset mechanism is provided on the base 1 to enable the auxiliary cam 6 to reset normally and maintain the normal locking auxiliary cam groove trajectory. When the die frame assembly experiences a blank jamming abnormality during operation, the swing arm roller 10 can push the auxiliary cam 6 to overcome the elastic force of the second elastic reset mechanism, causing the auxiliary cam 6 to rotate around the hinge and displace to avoid the jamming. This allows the abnormal swing arm roller 10 to pass smoothly through the abnormal locking auxiliary cam groove area formed by the displacement of the auxiliary cam 6, thereby reducing the probability of collisions of related parts and downtime for maintenance. After the abnormal swing arm roller 10 passes through, the auxiliary cam 6 can be reset in time under the action of the second elastic reset mechanism to restore the normal locking auxiliary cam groove trajectory.

[0047] like Figure 4 and Figure 9As shown, the auxiliary cam 6 is located above the movable cam 4. The structure of the second elastic reset mechanism is as follows: a first connecting seat 8 is fixedly provided on the auxiliary cam 6, and a second connecting seat 9 is fixed to the base 1 by a bracket 91. In actual manufacturing, the second connecting seat 9 and the first connecting seat 8 can be at the same height. A reset power mechanism that allows the auxiliary cam 6 to rotate and reset around its hinge is provided between the first connecting seat 8 and the second connecting seat 9. A second limiting mechanism that can limit the reset position of the auxiliary cam 6 is also provided.

[0048] The structure of the reset power mechanism is as follows: one end of the guide shaft 101 is fixed on the first connecting seat 8, and the other end of the guide shaft 101 extends into the connecting hole of the second connecting seat 9; a reset spring 102 is fitted on the guide shaft 101, and the two ends of the reset spring 102 abut against the first connecting seat 8 and the second connecting seat 9 respectively. The auxiliary cam 6 can compress the reset spring 102 under the action of external force to make the first connecting seat 8 move closer to the second connecting seat 9, thereby achieving rotational avoidance. After the action of external force disappears, the elastic force of the reset spring 102 makes the first connecting seat 8 move away from the second connecting seat 9, thereby driving the auxiliary cam 6 to rotate and reset.

[0049] In addition to being fixed to the first connecting seat 8, the guide shaft 101 can also be fixed to the second connecting seat 9. Specifically, the structure of the reset power mechanism is as follows: one end of the guide shaft 101 is fixed to the second connecting seat 9, and the other end of the guide shaft 101 extends into the connecting hole of the first connecting seat 8; a reset spring 102 is fitted on the guide shaft 101, and the two ends of the reset spring 102 abut against the first connecting seat 8 and the second connecting seat 9 respectively. The auxiliary cam 6 can compress the reset spring 102 under the action of external force to make the first connecting seat 8 move closer to the second connecting seat 9, thereby achieving rotational avoidance. After the action of external force disappears, the elastic force of the reset spring 102 makes the first connecting seat 8 move away from the second connecting seat 9, thereby driving the auxiliary cam 6 to rotate and reset.

[0050] A better solution is to provide connecting holes in both the first connecting seat 8 and the second connecting seat 9, with the two ends of the return spring 102 abutting against the bottom of the connecting hole in the first connecting seat 8 and the bottom of the connecting hole in the second connecting seat 9, respectively. The movable end of the guide shaft 101 has a clearance in the corresponding connecting hole for the guide shaft 101 to move.

[0051] Since there is relative movement between the movable cam 4 and the auxiliary cam 6, a wear-resistant support block can be provided between the movable cam 4 and the auxiliary cam 6 to protect them. When the movable cam 4 is composed of a transition connecting seat 41 and a movable cam 42, the wear-resistant support block is located between the movable cam 42 and the auxiliary cam 6.

[0052] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the structure of the second limiting mechanism in this embodiment is as follows: a second limiting block 19 is fixedly provided on the inner cam 3 located on the inner side of the front part of the auxiliary cam 6. The position of the second limiting block 19 is such that when the front part of the auxiliary cam 6 rotates towards the second limiting block 19 around the hinge point of the head of the auxiliary cam 6, the inner sidewall of the front part of the auxiliary cam 6 is blocked by the second limiting block 19 and cannot continue to rotate in that direction. Figure 4 The diagram shows the state when the inner front wall of the auxiliary cam 6 abuts against the second limit block 19. In this state, the reset position of the auxiliary cam 6 is the location where the locking auxiliary cam groove 18, formed between the auxiliary cam profile 61 and the rest section cam profile 22, can function normally. This position provides protection for the normal locking operation of the mold frame assembly. The remaining portion of the outer wall of the auxiliary cam 6, excluding the auxiliary cam profile 61, forms the third clearance surface 62. The third clearance surface 62 must be recessed inwards to ensure that it does not interfere with normal mold closing operations.

[0053] When the rocker arm roller 10 on a mold frame assembly enters the mold closing cam groove 16 from the fixed trajectory cam groove 14, the mold frame assembly corresponding to the rocker arm roller 10 is still in the mold closing process. When the rocker arm roller 10 enters the locking auxiliary cam groove 18 from the mold closing cam groove 16, the rocker arm roller 10 switches from completing the mold closing work to providing locking protection for the mold frame assembly. The auxiliary cam 6 and the movable cam 42 complement each other, which is equivalent to adding a rest section without interfering with the mold closing, thus providing protection for the locking of the mold frame assembly after mold closing.

[0054] If the manipulator's blank feeding malfunctions and causes blank jamming, the swing arm roller 10 on the mold frame assembly with blank jamming cannot return to its normal position. When the abnormal swing arm roller 10 enters the mold closing cam groove 16 from the fixed trajectory cam groove 14, the movable cam 4 is pushed to reposition and avoid it, so that the swing arm roller 10 can also pass smoothly through the mold closing cam groove 16 area. This can greatly reduce the probability of collisions between related parts and downtime for maintenance. At this time, the rotation of the movable cam 4 will not interfere with the auxiliary cam, and therefore will not interfere with the swing arm roller that is already in the locking auxiliary cam groove 18. If the mold frame assembly corresponding to the swing arm roller that is already in the locking auxiliary cam groove 18 is not jammed, it can perform normal auxiliary mold frame assembly locking operation, providing protection for the locking operation of the mold frame assembly. When the swing arm roller 10 on the mold frame assembly with a blank jamming problem enters the locking auxiliary cam groove 18 from the mold closing cam groove 16, the auxiliary cam 6 is forcibly pressed, compressing the return spring 102 and pushing the auxiliary cam 6 to reposition and avoid the jamming problem, allowing the swing arm roller 10 to pass smoothly through the locking auxiliary cam groove 18 area. At this time, the swing of the auxiliary cam 6 will not interfere with the active cam 42, which has been reset under the action of the first elastic reset mechanism, and therefore will not interfere with the swing arm roller in the mold closing cam groove 16 in the subsequent process. If the mold frame assembly corresponding to the swing arm roller in the mold closing cam groove 16 is not jammed, it can perform normal mold closing operation. After the abnormal swing arm roller 10 passes smoothly through the locking auxiliary cam groove 18, the auxiliary cam 6 will be reset normally in time under the action of the second elastic reset mechanism.

[0055] The present invention also provides a multi-cavity blow molding machine, including the above-described mold opening and closing cam with locking protection.

[0056] The mold-opening and closing cam of this invention, comprising a small-angle movable cam and an auxiliary cam, operates flexibly and reliably during operation. It effectively addresses blank jamming issues and provides protection for the locking operation of the mold frame assembly, reducing the probability of locking malfunctions. In particular, the double-layer design of the movable cam and auxiliary cam stacked on top of each other further enhances the overall compactness of the structure, significantly saving installation space. Multi-cavity blow molding machines employing the mold-opening and closing cam of this invention greatly improve the stability of equipment operation, thereby further ensuring and increasing the production capacity and efficiency of the multi-cavity blow molding machine.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any modifications or equivalent changes made based on the technical essence of the present invention shall still fall within the scope of protection claimed by the present invention.

Claims

1. A mold opening and closing cam with locking protection in a multi-cavity blow molding machine, including: A base is provided with a fixed trajectory cam, which consists of an outer cam and an inner cam. The inner sidewall cam profile of the outer cam and the outer sidewall cam profile of the inner cam form a fixed trajectory cam groove that defines the running trajectory of the rocker arm roller. The feature is that: the inner cam is disconnected in the mold closing area, and the bottom surface of the tail of the inner cam has a mounting groove between it and the base; the head of the movable cam is inserted into the mounting groove and hinged in the mounting groove; the movable cam has a movable cam profile, and the movable cam profile and the inner sidewall cam profile of the outer cam form a mold closing cam groove that defines the running trajectory of the rocker arm roller to enable the mold frame assembly to close normally. The mold closing cam groove is connected to the fixed trajectory cam groove, and the length of the mold closing cam groove during operation cannot allow the rocker arm rollers of two or more mold frame assemblies to enter the mold closing cam groove at the same time. A first elastic reset mechanism is provided on the base to enable the movable cam to be reset normally so as to maintain the normal mold closing cam groove trajectory. When the mold frame assembly experiences blank jamming abnormality during operation, the swing arm roller can push the movable cam to overcome the elastic force of the first elastic reset mechanism, so that the movable cam rotates around the hinge to avoid the impact. The outer cam, corresponding to the locking section of the opening and closing cam in the multi-cavity blow molding machine, has a rest section cam profile at its tail. An auxiliary cam is also provided, with its head hinged to the tail of the inner cam. The auxiliary cam has an auxiliary cam profile, and a locking auxiliary cam groove is formed between the auxiliary cam profile and the rest section cam profile to limit the running trajectory of the rocker arm roller and provide protection for the locking operation of the mold frame assembly. The locking auxiliary cam groove is connected to the mold closing cam groove. A second elastic reset mechanism is provided on the base to enable the auxiliary cam to reset normally and maintain the normal locking auxiliary cam groove trajectory. When the blank jamming abnormality occurs during operation, the rocker arm roller of the mold frame assembly can push the auxiliary cam to overcome the elastic force of the second elastic reset mechanism, so that the auxiliary cam rotates around the hinge to avoid the obstruction.

2. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 1, characterized in that: The structure of the first elastic reset mechanism is as follows: an adjustment groove is provided on the base, the top of the adjustment shaft passes through the adjustment groove and is fixedly connected to the movable cam component, and a power source that can drive the adjustment shaft to rotate and reset the movable cam component around the hinge of the head of the movable cam component is provided between the base and the adjustment shaft extending out of the base.

3. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 2, characterized in that: The power source is a cylinder that is hinged to the base, and the end of the piston rod of the cylinder is hinged to the bottom of the adjusting shaft.

4. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 1, 2, or 3, characterized in that: The movable cam component includes: a transition connecting seat and a movable cam, the movable cam being fixed to the top of the transition connecting seat; the front end of the transition connecting seat extends beyond the front end of the movable cam, and the head of the transition connecting seat extends into the mounting groove and is hinged in the mounting groove; the movable cam is located outside the mounting groove, and the outline of the movable cam is located on the outer side wall of the movable cam; a first limiting mechanism is also provided to limit the reset position of the movable cam component.

5. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 4, characterized in that: The outer side wall of the tail of the transition connector is recessed inward to avoid obstructing the operation of the swing arm roller. The structure of the first limiting mechanism is as follows: the outer side wall of the tail of the transition connector is recessed inward to avoid obstructing the operation of the swing arm roller. A first limiting block is fixedly installed on the base located outside the tail of the transition connector. The position of the first limiting block is such that when the movable cam rotates around the hinge of the head of the movable cam towards the first limiting block and resets until the limiting surface abuts against the first limiting block, it is blocked by the first limiting block and cannot continue to rotate in that direction.

6. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 1, 2, or 3, characterized in that: The auxiliary cam is located above the movable cam component. The structure of the second elastic reset mechanism is as follows: a first connecting seat is fixedly provided on the auxiliary cam, and a second connecting seat is fixed to the base by a bracket. A reset power mechanism that allows the auxiliary cam to rotate and reset around its hinge is provided between the first connecting seat and the second connecting seat; a second limiting mechanism that can limit the reset position of the auxiliary cam is also provided. The structure of the reset power mechanism is as follows: one end of the guide shaft is fixed on the first connecting seat, and the other end of the guide shaft extends into the connecting hole of the second connecting seat; a reset spring is fitted on the guide shaft, and the two ends of the reset spring abut against the first connecting seat and the second connecting seat respectively. The auxiliary cam can compress the reset spring under the action of external force to make the first connecting seat move closer to the second connecting seat. After the action of external force disappears, the elastic force of the reset spring will make the first connecting seat move away from the second connecting seat, thereby driving the auxiliary cam to rotate and reset. Alternatively, the structure of the reset power mechanism is as follows: one end of the guide shaft is fixed to the second connecting seat, and the other end of the guide shaft extends into the connecting hole of the first connecting seat; a reset spring is fitted on the guide shaft, and the two ends of the reset spring abut against the first connecting seat and the second connecting seat respectively. The auxiliary cam can compress the reset spring under the action of external force to make the first connecting seat move closer to the second connecting seat. After the action of external force disappears, the elastic force of the reset spring will make the first connecting seat move away from the second connecting seat, thereby driving the auxiliary cam to rotate and reset.

7. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 6, characterized in that: The structure of the second limiting mechanism is as follows: a second limiting block is fixedly installed on the inner cam located on the inner side of the front part of the auxiliary cam. The position of the second limiting block is such that when the auxiliary cam rotates around the hinge of the head of the auxiliary cam towards the second limiting block and resets, the inner side wall of the front part of the auxiliary cam is blocked by the second limiting block and cannot continue to rotate in that direction.

8. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 1, characterized in that: The hinge shaft at the head of the movable cam, which is hinged in the mounting groove, shares the same hinge shaft as the hinge shaft at the head of the auxiliary cam, which is hinged at the tail of the inner cam.

9. The mold opening and closing cam with locking protection in the multi-cavity blow molding machine according to claim 6, characterized in that: A wear-resistant support block is provided between the movable cam and the auxiliary cam.

10. A multi-cavity blow molding machine, characterized in that: The multi-cavity blow molding machine includes the mold opening and closing cam with locking protection as described in any one of claims 1-9.

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