A PU automatic forming production line mold opening and lifting device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- NANTONG HUIHONG REHABILITATION EQUIP CO LTD
- Filing Date
- 2025-12-09
- Publication Date
- 2026-07-21
Smart Images
Figure CN121374969B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of PU automatic molding equipment technology, specifically to a mold opening and lifting device for an automatic PU molding production line. Background Technology
[0002] A prior art patent, CN211105199U, discloses a cylinder lifting platform for a polyurethane foam mold base. This platform includes a bottom mold, a top mold, and a pressing platform for pushing the top mold. It also includes a base frame and a support platform at the bottom of the bottom mold, with a base mounted on the bottom of the support platform. After polyurethane foam material is poured into the bottom mold, the pressing platform pushes the top and bottom molds together. The cylinder then pushes the base upwards, lifting the bottom mold via the support platform. This effectively reduces the gap between the bottom and top molds, ensuring the polyurethane foam material is evenly distributed inside the mold. During the cylinder's pushing process, excessive force can occur. A buffer component is included; during this process, the component contracts, effectively increasing the cushioning performance of the fixing plate and preventing excessive pressure on the top and bottom molds from causing damage.
[0003] However, the aforementioned device still has significant drawbacks in its use: Both the aforementioned device and existing polyurethane molding dies employ a one-time molding structure, consisting of an upper and lower mold forming a cavity. Foaming is achieved by adding liquid PU to this cavity. While this method can produce most polyurethane products with uniform structural properties, actual production involves polyurethane foam structures composed of different physical properties. For such structures, multiple molding and foaming processes are required. For example, in the production of polyurethane tires, the inner tire carcass of the rim needs greater structural strength to improve the tire's impact resistance, while the outer tire carcass needs greater elasticity to improve the tire's cushioning characteristics during road travel. These two different tire carcass structures require different raw materials and proportions, making a one-time molding process impossible. In summary, existing technologies for polyurethane foam molding structures with different raw material proportions suffer from cumbersome steps and insufficient structural bonding. Summary of the Invention
[0004] The purpose of this invention is to provide a mold opening and lifting device for an automated PU molding production line to solve the problems mentioned in the background art.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A mold opening and lifting device for an automatic PU molding production line includes a base, a lifting plate, and a top plate. The base and the top plate are connected by sliding rods fixedly installed at the four corners. The four corners of the lifting plate are connected to the four sliding rods by sliding rod sleeves, so that the lifting plate can move up, down, and slide between the base and the top plate. The upper mold is rotatably mounted on the top plate via a rotating shaft. The lifting plate is provided with a turntable groove, and a rotating base coaxial with the upper mold is provided in the turntable groove. The rotating base is connected to the lifting plate through a rotating support. A lower mold is installed on the rotating base. The lower mold cooperates with the upper mold during the lifting plate's upward movement, and the centrifugal force generated by the synchronous fixed-axis rotation promotes the uniform distribution of the added PU liquid. The lower mold includes an inner ring, a lifting isolation ring, and an outer ring. Both the inner and outer rings are fixedly connected to a rotating base via connecting columns. The lifting isolation ring is positioned in the gap between the inner and outer rings and moves vertically under the action of a lifting drive mechanism, allowing the upper and lower molds to operate in two sequential states: internal foaming molding and external foaming molding. In the internal foaming molding working state, the lifting isolation ring rises inside the upper mold and the lower mold, and the upper end face of the lifting isolation ring abuts against the inner bottom surface of the upper mold. At this time, the upper mold, the lifting isolation ring and the inner ring surround and form an internal foaming cavity. By adding PU into the internal foaming cavity, a foamed inner ring is formed. In the external foaming molding process, the lifting isolation ring descends within the upper and lower molds, with its upper end face flush with the upper end face of the inner ring. At this time, the molded foamed inner ring, upper mold, lifting isolation ring, inner ring, and outer ring together form an outer foaming cavity. PU is then added to the outer foaming cavity to form the foamed outer ring.
[0006] Preferably, a plurality of first lifting hydraulic cylinders are provided between the base and the lifting plate. The telescopic arms of the first lifting hydraulic cylinders are fixedly connected to the lifting plate, and the lifting plate is driven to slide horizontally by the telescopic movement of the first lifting hydraulic cylinders.
[0007] Preferably, a plurality of second lifting hydraulic cylinders are also fixedly installed on the rotating base. The telescopic arms of the second lifting hydraulic cylinders are fixedly connected to the bottom of the lifting isolation ring. The telescopic movement of the second lifting hydraulic cylinders drives the lifting isolation ring to switch its working state.
[0008] Preferably, sealing rings are provided on the abutting end face of the upper mold and the outer ring, the abutting end face of the upper mold and the lifting isolation ring, and the abutting end face of the lifting isolation ring and the inner and outer rings, so as to ensure the sealing of the inner foaming cavity and the outer foaming cavity.
[0009] Preferably, a drive gear ring is also fixedly installed on the outer edge of the rotating base. The drive gear ring meshes with a drive gear fixedly installed on the drive shaft of the centrifugal motor. The centrifugal motor is fixedly installed on the lifting plate. The rotation of the centrifugal motor drives the upper mold and the lower mold to perform centrifugal rotation synchronously.
[0010] Preferably, the upper mold also has a first feeding port that passes through the rotating shaft and the top plate, through which PU liquid is added to the foaming cavity.
[0011] Preferably, a second feeding port is also provided on the outer ring, through which PU liquid is added to the outer foaming cavity.
[0012] Preferably, both the first and second feeding ports are sealed by detachably installed sealing blocks.
[0013] Preferably, the lifting isolation ring has an annular groove on one side of the inner foaming cavity. The annular groove is isolated from the external environment by an expanded rubber membrane. The lifting isolation ring inside the annular groove also has an air inlet and outlet hole. The air inlet and outlet hole is connected to a bidirectional air pump fixedly installed on the rotating base through a pipe. The expansion rubber membrane is changed by the inflation and deflation of the bidirectional air pump.
[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a specially designed lower mold, breaking away from the conventional understanding of existing technologies. It enables the one-time molding of polyurethane foam materials with different properties and characteristics, greatly simplifying the process steps and improving the bonding strength between polyurethane materials with different properties, making it suitable for widespread application. Attached Figure Description
[0015] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention; Figure 2 This is a cross-sectional view of the overall structure of the present invention; Figure 3 This is a front view schematic diagram of the overall structure of the present invention; Figure 4 This is a cross-sectional schematic diagram of the upper and lower molds of the present invention; Figure 5 This is a schematic diagram illustrating the two working modes of internal foaming molding and external foaming molding of the present invention; Figure 6 This is a schematic diagram illustrating the changes in the concave and convex shape of the expanded rubber film of the present invention.
[0016] In the diagram: 1. Base, 2. Lifting plate, 3. Top plate, 4. Slide rod, 5. Slide rod sleeve, 6. Rotating shaft, 7. Upper mold, 8. Rotary support, 9. Inner ring, 10. Lifting isolation ring, 11. Outer ring, 12. Inner foaming cavity, 13. Outer foaming cavity, 14. First lifting hydraulic cylinder, 15. Second lifting hydraulic cylinder, 16. Drive gear ring, 17. First feeding port, 18. Second feeding port, 19. Annular groove, 20. Expanding rubber membrane, 21. Air inlet and outlet, 22. Connecting column, 23. Rotating base. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] Please see Figure 1-6 The present invention provides a technical solution: Example 1:
[0019] A PU automatic molding production line mold opening and lifting device includes a base 1, a lifting plate 2 and a top plate 3. The base 1 and the top plate 3 are connected by sliding rods 4 fixedly installed at the four corners. The four corners of the lifting plate 2 are connected to the four sliding rods 4 by sliding rod sleeves 5 installed at the four corners, so that the lifting plate 2 can move up, down and slide between the base 1 and the top plate 3. The upper mold 7 is mounted on the top plate 3 in a fixed-axis rotatable manner via the rotating shaft 6; The lifting plate 2 has a turntable groove, and a rotating base 23 coaxial with the upper mold 7 is set in the turntable groove. The rotating base 23 is connected to the lifting plate 2 through a rotating support 8. A lower mold is installed on the rotating base 23. The lower mold cooperates with the upper mold 7 during the lifting process of the lifting plate 2, and the centrifugal force generated by the synchronous fixed axis rotation motion promotes the uniform distribution of the added PU liquid inside. The lower mold includes an inner ring 9, a lifting isolation ring 10, and an outer ring 11. Both the inner ring 9 and the outer ring 11 are fixedly connected to the rotating base 23 via connecting posts 22. The lifting isolation ring 10 is vertically positioned at the gap formed between the inner ring 9 and the outer ring 11. The lifting isolation ring 10 moves vertically under the operation of a lifting drive mechanism, allowing the upper mold 7 and the lower mold to have two sequential working states: internal foaming molding and external foaming molding. In the internal foaming molding working state, the lifting isolation ring 10 rises in the upper mold 7 and the lower mold, and the upper end face of the lifting isolation ring 10 abuts against the inner bottom surface of the upper mold 7. At this time, the upper mold 7, the lifting isolation ring 10 and the inner ring 9 enclose and form an internal foaming cavity 12. By adding PU into the internal foaming cavity 12, a foamed inner ring is formed. In the external foaming molding working state, the lifting isolation ring 10 descends in the upper mold 7 and the lower mold. The upper end face of the lifting isolation ring 10 is flush with the upper end face of the inner ring 9. At this time, the formed foamed inner ring, upper mold 7, lifting isolation ring 10, inner ring 9 and outer ring 11 together enclose the outer foaming cavity 13. The foamed outer ring is formed by adding PU into the outer foaming cavity 13.
[0020] In this embodiment, the base 1, top plate 3, and slide rod 4 constitute the main frame structure of the device. A lifting plate 2 is installed on the slide rod 4, and the lifting plate 2 slides and moves up and down along the length of the slide rod 4. The top plate 3 is rotatably mounted on the bottom of the top plate 3, and the lifting plate 2 is mounted on the lower mold via a rotating support 8. The upper mold 7 and the lower mold cooperate to perform a mold closing operation. Unlike the prior art, the lower mold includes an inner ring 9, a lifting isolation ring 10, and an outer ring 11. The inner ring 9 and the outer ring 11 are fixedly connected to the rotating base 23 via a connecting column 22. The lifting isolation ring 10 is movably positioned in the gap formed by the inner ring 9 and the outer ring 11. When the upper end face of the lifting isolation ring 10 abuts against the inner bottom surface of the upper mold 7, the upper mold 7, the lifting isolation ring 10, and the inner ring 9 enclose an inner foaming cavity 12. At this time, PU is added to the inner foaming cavity 12 to form a foamed inner ring, thus forming an inner foam. After the inner ring 9 is formed, no demolding is required. The lifting isolation ring 10 is driven down so that its upper surface is flush with the upper surface of the inner ring 9. At this time, the formed foamed inner ring, upper mold 7, lifting isolation ring 10, inner ring 9 and outer ring 11 together form the outer foaming cavity 13. PU is then added into the outer foaming cavity 13 to form the foamed outer ring. In this way, two different types of polyurethane foam materials can be formed without demolding. Compared with the existing technology of separate molding and manual assembly, this molding method simplifies the production process. The PU material added to the outer ring can adhere tightly to the foamed inner ring during the foaming process. Furthermore, by increasing the roughness and unevenness of the outer surface of the foamed inner ring, a more tightly bonded polyurethane material can be produced. Compared with the assembly method after separate molding, the bonding between materials in this molding process is more compact. Example 2:
[0021] A number of first lifting hydraulic cylinders 14 are provided between the base 1 and the lifting plate 2. The telescopic arms of the first lifting hydraulic cylinders 14 are fixedly connected to the lifting plate 2. The lifting plate 2 is driven to slide horizontally by the telescopic movement of the first lifting hydraulic cylinders 14.
[0022] Several second lifting hydraulic cylinders 15 are also fixedly installed on the rotating base 23. The telescopic arms of the second lifting hydraulic cylinders 15 are fixedly connected to the bottom of the lifting isolation ring 10. The telescopic movement of the second lifting hydraulic cylinders 15 drives the lifting isolation ring 10 to switch working states.
[0023] In this embodiment, a drive mechanism for driving the lifting plate 2 and the lifting isolation ring 10 to move up and down is disclosed. Both adopt a hydraulic telescopic cylinder lifting scheme. This type of device has the characteristic of high lifting pressure. Considering that this type of electric hydraulic cylinder telescopic scheme is common in the prior art, it will not be described in detail here. Example 3:
[0024] Sealing rings are provided on the abutting end face of the upper mold 7 and the outer ring 11, the abutting end face of the upper mold 7 and the lifting isolation ring 10, and the abutting end face of the lifting isolation ring 10 and the inner ring 9 and the outer ring 11. The sealing of the inner foaming cavity 12 and the outer foaming cavity 13 is ensured by the setting of the sealing rings.
[0025] In this embodiment, considering that the polyurethane foam material needs to ensure the sealing between the upper mold 7 and the lower mold during the molding process, a sealing ring is provided in the area that needs to be sealed, thereby improving the airtightness of the device and effectively preventing leakage of the foam material during the molding process. Example 4:
[0026] A drive gear ring 16 is also fixedly installed on the outer edge of the rotating base 23. The drive gear ring 16 meshes with the drive gear fixedly installed on the centrifugal motor drive shaft. The centrifugal motor is fixedly installed on the lifting plate 2. The rotation of the centrifugal motor drives the upper mold 7 and the lower mold to perform centrifugal rotation synchronously.
[0027] In this embodiment, a technical solution is disclosed that the rotating base 23 is driven to rotate by a motor. This type of driving mechanism is quite common in real life. When the upper mold 7 and the lower mold are engaged, in order to ensure the uniformity of foaming molding in each part, the rotating base 23 is rotated to drive the lower mold to rotate, which in turn drives the upper mold 7, which is engaged with it, to rotate synchronously. Centrifugal force is used to make the PU material added inside evenly distributed, thereby ensuring the uniformity of subsequent foaming molding. Example 5:
[0028] The upper mold 7 also has a first feeding port 17 that passes through the rotating shaft 6 and the top plate 3, through which PU liquid is added to the foaming cavity 12.
[0029] A second feeding port 18 is also provided on the outer ring 11, through which PU liquid is added to the outer foaming cavity 13.
[0030] Both the first feeding port 17 and the second feeding port 18 are sealed by detachable sealing blocks.
[0031] In this embodiment, PU material is added through the first feeding port 17 and the second feeding port 18 respectively, and after the addition is completed, it is sealed by a sealing block to ensure the internal airtightness. Since this sealing method using a sealing block is common in the field, it is not shown in detail in the accompanying drawings. The sealing block can be sealed through the inlet or by an electromechanical structure connected to it, which is within the scope of use of this embodiment. Example 6:
[0032] The lifting isolation ring 10 is located on one side of the inner foaming cavity 12 and has an annular groove 19. The annular groove 19 is isolated from the external environment by the expansion rubber membrane 20. The lifting isolation ring 10 inside the annular groove 19 also has an air inlet and outlet hole 21. The air inlet and outlet hole 21 is connected to a bidirectional air pump fixedly installed on the rotating base 23 through a pipe. The concave and convex shape of the expansion rubber membrane 20 is changed by the inflation and deflation of the bidirectional air pump.
[0033] In this embodiment, an annular groove 19 is further provided inside the lifting isolation ring 10, and the annular groove 19 is sealed by an expanding rubber membrane 20, as shown in the appendix to the specification. Figure 6 When air is drawn into the annular groove 19 through the air inlet / outlet 21, the expanding rubber diaphragm 20 exhibits... Figure 6 Similarly, with its concave shape at the top and middle, when air is injected into the annular groove 19 through the air inlet / outlet 21, the expanding rubber membrane 20 exhibits... Figure 6 The convex shape at the bottom center is designed so that during the foaming process of the inner foam ring, air is injected into the air inlet / outlet 21, causing the expanding rubber membrane 20 to bulge outward. Correspondingly, the convex expanding rubber membrane 20 compresses the space in the PU foaming process, thus forming a concave shape on the outer edge of the molded inner foam ring. After the inner foam ring is formed, air is drawn into the annular groove 19 through the air inlet / outlet 21. At this time, the expanding rubber membrane 20 changes from a convex shape to a concave shape. During this process, the expanding rubber membrane 20 detaches from the surface of the inner foam ring and... This reduces friction during the descent of the lifting isolation ring 10, making it easier for it to transition to an external foaming molding state. The concave shape formed on the outer edge of the inner foam ring allows it to form a convex-concave surface bond with the outer foam ring during the external foaming molding process, resulting in a tighter bond between the inner and outer foam rings. The expanding rubber membrane 20 changes shape during the operation of the bidirectional air pump, which is fixedly mounted on the rotating base 23 to achieve inflation and deflation operations. Considering that this inflation and deflation mechanism is common in the prior art, it will not be described in detail here.
[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A mold opening and lifting device for an automatic PU molding production line, comprising a base, a lifting plate, and a top plate, wherein the base and the top plate are connected by sliding rods fixedly installed at four corners, and the four corners of the lifting plate are respectively engaged with the four sliding rods by sliding rod sleeves, so that the lifting plate can move up, down, and slide between the base and the top plate; characterized in that: The upper mold is rotatably mounted on the top plate via a rotating shaft. The lifting plate is provided with a turntable groove, and a rotating base coaxial with the upper mold is provided in the turntable groove. The rotating base is connected to the lifting plate through a rotating support. A lower mold is installed on the rotating base. The lower mold cooperates with the upper mold during the lifting plate's upward movement, and the centrifugal force generated by the synchronous fixed-axis rotation promotes the uniform distribution of the added PU liquid. The lower mold includes an inner ring, a lifting isolation ring, and an outer ring. Both the inner and outer rings are fixedly connected to a rotating base via connecting columns. The lifting isolation ring is positioned in the gap between the inner and outer rings and moves vertically under the action of a lifting drive mechanism, allowing the upper and lower molds to operate in two sequential states: internal foaming molding and external foaming molding. In the internal foaming molding working state, the lifting isolation ring rises inside the upper mold and the lower mold, and the upper end face of the lifting isolation ring abuts against the inner bottom surface of the upper mold. At this time, the upper mold, the lifting isolation ring and the inner ring surround and form an internal foaming cavity. By adding PU into the internal foaming cavity, a foamed inner ring is formed. In the external foaming molding working state, the lifting isolation ring descends in the upper mold and the lower mold. The upper end face of the lifting isolation ring is flush with the upper end face of the inner ring. At this time, the formed foamed inner ring, upper mold, lifting isolation ring, inner ring and outer ring together enclose the outer foaming cavity. The foamed outer ring is formed by adding PU into the outer foaming cavity. The lifting isolation ring has an annular groove on one side of the inner foaming cavity. The annular groove is isolated from the external environment by an expanded rubber membrane. The lifting isolation ring inside the annular groove also has air inlet and outlet holes. The air inlet and outlet holes are connected to a bidirectional air pump fixedly installed on the rotating base through pipes. The expansion rubber membrane is changed by the inflation and deflation of the bidirectional air pump.
2. The mold opening and lifting device for an automatic PU molding production line according to claim 1, characterized in that: A plurality of first lifting hydraulic cylinders are provided between the base and the lifting plate. The telescopic arms of the first lifting hydraulic cylinders are fixedly connected to the lifting plate. The extension and retraction of the first lifting hydraulic cylinders drives the lifting plate to slide horizontally.
3. The mold opening and lifting device for an automatic PU molding production line according to claim 1 or 2, characterized in that: Several second lifting hydraulic cylinders are also fixedly installed on the rotating base. The telescopic arms of the second lifting hydraulic cylinders are fixedly connected to the bottom of the lifting isolation ring. The telescopic movement of the second lifting hydraulic cylinders drives the lifting isolation ring to switch its working state.
4. The mold opening and lifting device for an automatic PU molding production line according to claim 3, characterized in that: Sealing rings are provided on the abutting end face of the upper mold and the outer ring, the abutting end face of the upper mold and the lifting isolation ring, and the abutting end face of the lifting isolation ring and the inner and outer rings. The sealing of the inner foaming cavity and the outer foaming cavity is ensured by the setting of the sealing rings.
5. The mold opening and lifting device for an automatic PU molding production line according to claim 4, characterized in that: A drive gear ring is also fixedly installed on the outer edge of the rotating base. The drive gear ring meshes with a drive gear fixedly installed on the drive shaft of the centrifugal motor. The centrifugal motor is fixedly installed on the lifting plate. The rotation of the centrifugal motor drives the upper mold and the lower mold to perform centrifugal rotation synchronously.
6. The mold opening and lifting device for an automatic PU molding production line according to claim 5, characterized in that: The upper mold also has a first feeding port that passes through the rotating shaft and the top plate, through which PU liquid is added to the foaming cavity.
7. The mold opening and lifting device for an automatic PU molding production line according to claim 6, characterized in that: A second feeding port is also provided on the outer ring, through which PU liquid is added to the outer foaming cavity.
8. The mold opening and lifting device for an automatic PU molding production line according to claim 7, characterized in that: Both the first and second feeding ports are sealed by detachable sealing blocks.