A spare tire cover mold

Abstract

This utility model discloses a spare tire cover mold, including an upper injection mold and a lower injection mold. Four guide pillars are fixedly connected to the bottom of the upper injection mold, and four guide grooves are formed on the top of the lower injection mold. An injection cavity is formed on the top of the lower injection mold. Two geared motors are fixedly connected to the outer wall of the lower injection mold, and drive shafts are fixedly connected to the outer walls of the output shafts of both geared motors. In the demolding process, the two geared motors drive the drive shafts and eccentric wheels, converting circular motion into linear motion of a rectangular plate. Then, a sliding pillar guides the trapezoidal ejector pins to eject the plastic part. The special design of the trapezoidal ejector pins and trapezoidal grooves ensures contact only after complete resetting, completely solving the problem of reciprocating friction between traditional ejector elements and the hole wall. This effectively reduces metal fatigue, prevents flash and appearance defects caused by increased clearance, and ensures the surface quality and dimensional consistency of the spare tire cover.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a spare tire cover mold. Background Technology

[0002] A spare tire cover is an interior trim component installed in the trunk of a car to cover and secure the spare tire. It protects the spare tire from dust, impacts, and other external damage, while also creating a flat, load-bearing surface inside the trunk. Common materials include polypropylene (PP) honeycomb panels, polyurethane composites, and EPP foam layers. During production, molten plastic is typically injected into the mold cavity at a set pressure using an injection molding machine for one-time molding. After the spare tire cover is injection molded, due to its large molding surface, an ejector mechanism is needed to eject it. However, traditional injection mold ejector mechanisms usually rely on spring return or simple hydraulic / mechanical ejection. For example, the ejector element (such as ejector pins or ejector columns) generates continuous sliding friction with the mold cavity wall during reciprocating motion. This long-term friction and wear easily leads to an increase in the gap between the ejector element and the mating hole, not only producing flash, affecting product dimensional accuracy and appearance quality, but also shortening the mold's lifespan due to metal fatigue. Therefore, we propose a spare tire cover mold to solve the above problems. Utility Model Content

[0003] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a spare tire cover mold.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A spare tire cover mold includes an upper injection mold and a lower injection mold. Four guide pillars are fixedly connected to the bottom of the upper injection mold. Four guide grooves are formed on the top of the lower injection mold. An injection cavity is formed on the top of the lower injection mold. Two geared motors are fixedly connected to the outer wall of the lower injection mold. A drive shaft is fixedly connected to the outer wall of the output shaft of each of the two geared motors. An eccentric wheel is fixedly sleeved on the outer wall of each of the two drive shafts. Two rectangular plates are slidably connected inside the lower injection mold. Multiple grooves are formed inside the lower injection mold. Springs are fixedly connected inside each of the multiple grooves. A demolding assembly is provided on the outer wall of the lower injection mold.

[0006] Preferably, the demolding assembly includes multiple sliding pillars, the bottoms of which are fixedly connected to the tops of two rectangular plates, and the tops of each sliding pillar are fixedly connected to trapezoidal top pillars. The top of the injection mold has multiple trapezoidal grooves, the inner walls of which are slidably connected to the outer walls of the trapezoidal top pillars. The inner wall of the injection mold has multiple sliding holes, the inner walls of which are slidably connected to the outer walls of the sliding pillars.

[0007] Preferably, the outer walls of both the upper and lower injection molds are provided with reinforcing ribs, and multiple lifting rings are fixedly connected to the outer walls of both the upper and lower injection molds, providing a convenient interface for the handling and installation of the upper and lower injection molds.

[0008] Preferably, the outer wall of the injection mold has two circular holes, and the inner walls of the two circular holes are rotatably connected to the outer walls of the output shafts of the two geared motors, respectively.

[0009] Preferably, the bottoms of the two rectangular plates are in contact with the tops of the two eccentric wheels respectively. A cooling water pipe is fixedly installed inside the injection mold. One end of the cooling water pipe penetrates the outer wall of the injection mold and is fixedly connected to a water pump. The water pump delivers external water to the cooling water pipe so that the cooling water flows inside the cooling water pipe.

[0010] Preferably, the bottoms of multiple springs are fixedly connected to the tops of two rectangular plates, and the tops of multiple springs are fixedly connected to the inner walls of multiple grooves. The multiple springs can automatically reset the rectangular plates, sliding columns, and trapezoidal top columns through their own elastic force.

[0011] Compared with the prior art, the advantages of this utility model are:

[0012] This solution uses two geared motors to drive the transmission shaft and eccentric wheel in the demolding process, converting the circular motion into the linear motion of the rectangular plate. Then, the sliding column guides the trapezoidal ejector to eject the plastic part. The special design of the trapezoidal ejector and the trapezoidal groove ensures that they only make contact after the part has been fully reset, which completely solves the problem of reciprocating friction between the traditional ejector element and the hole wall. This effectively reduces metal fatigue, prevents flash and appearance defects caused by increased clearance, and ensures the surface quality and dimensional consistency of the spare tire cover. Attached Figure Description

[0013] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a cross-sectional structural diagram of a spare tire cover mold proposed in this utility model.

[0015] Figure 2 This is a schematic diagram of the injection molding lower mold structure of a spare tire cover mold proposed in this utility model;

[0016] Figure 3 This is a schematic diagram of the injection molding upper mold structure of a spare tire cover mold proposed in this utility model;

[0017] Figure 4This is a rear-view three-dimensional structural diagram of a spare tire cover mold proposed in this utility model.

[0018] In the diagram: 1. Upper injection mold; 2. Lower injection mold; 3. Guide pillar; 4. Guide groove; 5. Reinforcing rib; 6. Injection cavity; 7. Lifting ring; 8. Gear motor; 9. Rectangular plate; 10. Drive shaft; 11. Eccentric wheel; 12. Groove; 13. Spring; 14. Sliding pillar; 15. Trapezoidal top pillar. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] Depend on Figures 1-4 As shown, a spare tire cover mold is disclosed, including an upper injection mold 1 and a lower injection mold 2. Four guide pillars 3 are fixedly connected to the bottom of the upper injection mold 1, and four guide grooves 4 are provided on the top of the lower injection mold 2. The guide pillars 3 and guide grooves 4 provide guidance and positioning for the mold closing process of the upper injection mold 1 and the lower injection mold 2, and prevent misalignment of the upper and lower molds during mold closing.

[0021] Both the upper injection mold 1 and the lower injection mold 2 are provided with reinforcing ribs 5 on their outer walls. The reinforcing ribs 5 can enhance the structural strength of the mold shell. During the injection process, the mold will be subjected to high pressure impact of molten plastic. The reinforcing ribs 5 can effectively disperse stress and prevent the upper injection mold 1 and the lower injection mold 2 from deforming due to excessive force.

[0022] Multiple lifting rings 7 are fixedly connected to the outer walls of both the upper injection mold 1 and the lower injection mold 2. The multiple lifting rings 7 provide a convenient interface for the handling and installation of the upper injection mold 1 and the lower injection mold 2. When assembling them into the injection molding machine or performing maintenance and disassembly, the lifting rings 7 can be used in conjunction with the hoisting equipment.

[0023] The injection mold 2 has an injection cavity 6 at its top. Two geared motors 8 are fixedly connected to the outer wall of the injection mold 2. Two circular holes are opened on the outer wall of the injection mold 2. The inner walls of the two circular holes are rotatably connected to the outer walls of the output shafts of the two geared motors 8. A transmission shaft 10 is fixedly connected to the outer walls of the output shafts of the two geared motors 8. An eccentric wheel 11 is fixedly sleeved on the outer walls of the two transmission shafts 10. A bearing is fixedly sleeved on one end of the two transmission shafts 19. The outer ring of the bearing is fixedly connected to the inner wall of the injection mold 2. Two rectangular plates 9 are slidably connected inside the injection mold 2. The bottom of the two rectangular plates 9 is in contact with the top of the two eccentric wheels 11. The eccentric wheels 11 can convert the circular motion of the transmission shaft 10 into the vertical linear motion of the rectangular plates 9 (one rotation can complete one lifting and resetting), providing lifting power for the demolding assembly.

[0024] A cooling water pipe is fixedly installed inside the injection mold 2. One end of the cooling water pipe passes through the outer wall of the injection mold 2 and is fixedly connected to a water pump. Multiple grooves 12 are opened inside the injection mold 2. Springs 13 are fixedly connected inside each of the multiple grooves 12. The multiple grooves 12 provide installation and expansion space for the springs 13 to prevent the springs 13 from shifting or deforming when compressed. The bottom of the multiple springs 13 is fixedly connected to the top of the two rectangular plates 9 respectively, and the top of the multiple springs 13 is fixedly connected to the inner wall of the multiple grooves 12 respectively.

[0025] The outer wall of the injection mold 2 is provided with a demolding assembly, which includes multiple sliding pillars 14. The bottom of the multiple sliding pillars 14 is fixedly connected to the top of two rectangular plates 9 respectively. The top of each of the multiple sliding pillars 14 is fixedly connected to a trapezoidal top pillar 15. The top of the injection mold 2 is provided with multiple trapezoidal grooves. The inner walls of the multiple trapezoidal grooves are slidably connected to the outer walls of the multiple trapezoidal top pillars 15 respectively. The inner wall of the injection mold 2 is provided with multiple sliding holes. The inner walls of the multiple sliding holes are slidably connected to the outer walls of the multiple sliding pillars 14 respectively. The multiple sliding pillars 14 transmit the lifting force of the rectangular plates 9, drive the trapezoidal top pillars 15 to move synchronously, and achieve guidance through cooperation with the sliding holes to prevent the trapezoidal top pillars 15 from deviating when lifting.

[0026] Working principle: During injection molding, the upper injection mold 1 and the lower injection mold 2 are guided and positioned by the guide pillars 3 and the guide grooves 4 and then close together. The molten plastic is injected into the injection cavity 6 through the injection hole at the top of the upper injection mold 1. The lower injection mold 2 has a built-in cooling water pipe, and an external water source is introduced through a water pump to quickly cool down the plastic part and accelerate its molding.

[0027] After molding is completed, the upper injection mold 1 and the lower injection mold 2 open, and the two reduction motors 8 drive the two transmission shafts 10 to rotate one revolution, which drives the two eccentric wheels 11 to rotate synchronously. When the two eccentric wheels 11 rotate upward, they will squeeze the bottom of the two rectangular plates 9. After being pressed, the two rectangular plates 9 overcome the elastic force of multiple springs 13, drive multiple sliding pillars 14 to move upward along multiple sliding holes, and then drive the trapezoidal top pillar 15 to rise, ejecting the molded injection part.

[0028] After the ejection action is completed, as the eccentric wheel 11 rotates downward, the trapezoidal top post 15 is reset under the elastic force of the spring 13. During this process, the trapezoidal top post 15 and the trapezoidal groove do not produce reciprocating friction similar to hole fitting when they move up and down. They only come into contact with the trapezoidal groove after being fully reset, which effectively reduces metal fatigue caused by friction and avoids the problem of increased gap between the two.

[0029] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A spare tire cover mold, comprising an upper injection mold (1) and a lower injection mold (2), characterized in that, The bottom of the upper injection mold (1) is fixedly connected with four guide pillars (3), the top of the lower injection mold (2) is provided with four guide grooves (4), the top of the lower injection mold (2) is provided with an injection cavity (6), the outer wall of the lower injection mold (2) is fixedly connected with two reduction motors (8), the outer wall of the output shaft of the two reduction motors (8) is fixedly connected with a transmission shaft (10), the outer wall of the two transmission shafts (10) is fixedly sleeved with an eccentric wheel (11), the interior of the lower injection mold (2) is slidably connected with two rectangular plates (9), the interior of the lower injection mold (2) is provided with multiple grooves (12), the interior of the multiple grooves (12) is fixedly connected with springs (13), and the outer wall of the lower injection mold (2) is provided with a demolding assembly.

2. A tire cover mold as defined in claim 1, wherein The demolding assembly includes multiple sliding pillars (14), the bottom of which is fixedly connected to the top of two rectangular plates (9), and the top of each sliding pillar (14) is fixedly connected to a trapezoidal top pillar (15). The top of the injection mold (2) has multiple trapezoidal grooves, the inner walls of which are slidably connected to the outer walls of the trapezoidal top pillars (15). The inner wall of the injection mold (2) has multiple sliding holes, the inner walls of which are slidably connected to the outer walls of the sliding pillars (14).

3. A tire cover mold as defined in claim 1, wherein The outer walls of both the upper injection mold (1) and the lower injection mold (2) are provided with reinforcing ribs (5), and the outer walls of both the upper injection mold (1) and the lower injection mold (2) are fixedly connected with multiple lifting rings (7).

4. A spare tire cover mold according to claim 1, characterized in that, The outer wall of the injection mold (2) has two round holes, and the inner walls of the two round holes are rotatably connected to the outer walls of the output shafts of the two geared motors (8).

5. A tire cover mold as defined in claim 1, wherein The bottoms of the two rectangular plates (9) are in contact with the tops of the two eccentric wheels (11). A cooling water pipe is fixedly installed inside the injection mold (2). One end of the cooling water pipe passes through the outer wall of the injection mold (2) and is fixedly connected to a water pump.

6. A tire cover mold as defined in claim 1, wherein The bottoms of multiple springs (13) are fixedly connected to the tops of two rectangular plates (9), and the tops of multiple springs (13) are fixedly connected to the inner walls of multiple grooves (12).

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