A cover injection mold for a dust cover of a steering shaft of an automobile

Abstract

The utility model provides a cover body injection mold for automobile steering shaft dust cover, including mould support, the mould support inside slide installation is opposite and sets up the upper movable die and lower movable die, the upper movable die and lower movable die are fixed respectively with the hydraulic cylinder output end fixed mounting of corresponding mould support outside oneself, the upper movable die and lower movable die are provided with cavity, cooling water path and injection port in, and the injection port is with the injection head of mould support upper installation corresponding, the wheel rotation head of mould support inside rotation installation is fixed with a plurality of injection mold core, and the wheel rotation head is fixed with the drive part output end fixed mounting of mould support outside, the utility model discloses through many mold core wheel rotation operation and realizes injection and get piece parallel, and the efficiency is promoted, and the precision moulding prevents the leakage, and the failure and maintenance cost are reduced, and the wheel rotation head design keeps the mold core positioning precision, guarantees product consistency and prolongs the life.

Description

Technical Field

[0001] This utility model belongs to the field of injection mold technology, and in particular relates to an injection mold for a dust cover for an automotive steering shaft. Background Technology

[0002] In automotive steering systems, the steering shaft, as a core transmission component connecting the steering wheel and steering gear, is constantly exposed to complex working environments such as the engine compartment and chassis, making it susceptible to corrosion from external impurities such as dust, mud, and metal shavings. These impurities adhere to the surface of the steering shaft, accelerating wear on the shaft and seals, disrupting the lubrication environment of the steering system, leading to steering jerking, decreased precision, and in severe cases, even steering failure, threatening driving safety. Therefore, automotive steering shafts are generally equipped with dust covers. These dust covers are often corrugated elastic structures that effectively block the intrusion of external impurities by wrapping around the key transmission sections of the steering shaft, while also accommodating the axial expansion and angular deflection of the steering shaft during vehicle operation, ensuring the long-term stable operation of the steering system.

[0003] Due to the high structural precision and sealing requirements of automotive steering shaft dust covers, their production process mainly relies on injection molding. The injection mold is the core equipment determining the molding quality and production efficiency of the dust cover. During the injection molding process, the injection mold core is a key component, used to form the inner channel and corrugated structure of the dust cover, directly affecting the dimensional accuracy and shape consistency of the cover. However, existing injection molds for automotive steering shaft dust covers have significant technical defects: the injection mold core is usually fixedly connected to the upper or lower moving mold (i.e., moving or fixed mold), forming an integrated structure. This design means that after a single injection molding is completed, the mold operation must be stopped, and the operator must manually remove the molded dust cover from the mold core. Only after the removal operation is completed can the mold be restarted for the next injection molding operation.

[0004] This production model has several problems: First, the molds need to be stopped frequently to wait for parts to be picked up, which leads to production interruptions, a significant reduction in the number of effective injections per unit time, low production efficiency, and difficulty in meeting the needs of large-scale production of automotive parts; Second, during the part picking process, operators need to be in close contact with the molds and mold cores that have just been injected. If the molds are not cooled sufficiently, it is easy to cause burns to the operators.

[0005] Therefore, it is essential to invent an injection mold for a dust cover for automotive steering shafts. Utility Model Content

[0006] To solve the above-mentioned technical problems, this utility model provides an injection mold for a dust cover for an automotive steering shaft, comprising a mold support, an upper moving mold, a lower moving mold, a hydraulic cylinder, a cavity, a cooling water channel, an injection port, an injection head, a rotary head, a drive component, and injection mold cores. The upper and lower moving molds are slidably mounted on the inner side of the mold support, and are respectively fixed to the output ends of the hydraulic cylinders fixedly mounted on the outer side of the mold support. The upper and lower moving molds contain the cavity, cooling water channel, and injection port, with the injection port corresponding to the injection head mounted on the mold support. A plurality of injection mold cores are fixedly mounted on the rotary head rotatably mounted on the inner side of the mold support, and the rotary head is fixed to the output end of the drive component fixedly mounted on the outer side of the mold support.

[0007] Preferably, both the upper moving mold and the lower moving mold are provided with independent cooling water channels, which are located near the cavity, and both the upper moving mold and the lower moving mold are provided with inlets and outlets that communicate with the cooling water channels.

[0008] Preferably, after the cavities of the upper moving mold and the lower moving mold are combined together, they work together with the injection mold core to form the injection molding cavity of the corrugated dust cover. After the injection ports of the upper moving mold and the lower moving mold are combined together, they form the injection port, and the inner wall can be in close contact with the outer surface of the injection head of the mold support.

[0009] Preferably, the injection port formed by the injection port is connected to the cavity, wherein the cavity area near the injection port is a flow diversion area, and the flow diversion area is located on the end face of the injection mold core that extends into the cavity, that is, after the colloid is retained in the flow diversion area, it flows to the injection molding cavity portion between the injection mold core and the cavity.

[0010] Preferably, the axes of the plurality of injection mold cores are on the same plane, and one end of each injection mold core is fixedly mounted on the outer surface of the rotating head. The cross-section of the rotating head is an equilateral polygonal structure and is located on one side of the upper moving mold and the lower moving mold.

[0011] Preferably, the distance between the upper moving mold and the lower moving mold driven apart by the hydraulic cylinder allows the injection mold core to pass through, that is, the straight-line distance between the upper moving mold and the lower moving mold is greater than the diameter of the injection mold core.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] This invention utilizes a rotary head with several injection mold cores fixed circumferentially. A drive unit rotates the rotary head, and a hydraulic cylinder drives the upper and lower moving molds to slide and open along the mold support, creating a "multi-mold core rotation operation" mode. When a set of injection mold cores aligns with the cavities of the upper and lower moving molds and completes injection molding, the operator can simultaneously remove the dust cover from the cooled and formed injection mold core on the other side of the rotary head, without waiting for removal before starting the next injection cycle. This design completely eliminates the time wasted by the traditional "stopping the machine after injection to remove parts," enabling parallel injection and removal operations, significantly shortening the production cycle, increasing the effective injection batches per unit time by more than 30%, and significantly adapting to the needs of large-scale automotive parts production.

[0014] This invention achieves stable opening and closing of the upper and lower moving molds through a sliding structure inside the mold support, driven by a hydraulic cylinder. During mold closing, precise control of cavity alignment accuracy is achieved, preventing structural defects in the mold housing caused by mold closing deviations. Simultaneously, after the injection ports of the upper and lower moving molds are engaged, their inner walls fit tightly against the outer surface of the injection head on the mold support, effectively preventing colloid leakage during injection molding and reducing material waste and mold contamination. This structural design reduces the failure rate during injection molding, improves mold operational stability, and reduces equipment maintenance frequency and costs.

[0015] This utility model's rotary head adopts an equilateral polygonal cross-section structure, with the axes of all injection mold cores lying on the same plane. When the drive component rotates the rotary head, each injection mold core can accurately align with the cavity positions of the upper and lower moving molds, ensuring that the positioning error during mold core switching is less than 0.05mm. This design avoids the positioning deviation problem during manual mold core replacement in traditional molds, ensures the consistency of the dust cover during continuous production, and at the same time, the stable rotation of the rotary head reduces collision wear between the mold core and the cavity, extending the service life of the mold and mold core. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] Figure 2 This is a half-sectional structural diagram of the present invention.

[0018] Figure 3 This is a schematic diagram of the mold opening structure of the upper and lower molds of this utility model.

[0019] Figure 4 This is a utility model Figure 2 A magnified schematic diagram of the structure at point A.

[0020] In the picture:

[0021] 1. Mold support; 2. Upper moving mold; 3. Lower moving mold; 4. Hydraulic cylinder; 5. Cavity; 6. Cooling water channel; 7. Injection port; 8. Injection head; 9. Rotary head; 10. Drive component; 11. Injection mold core. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 should fall within the protection scope of the present invention.

[0023] In the description of the embodiments, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the present invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. In the description of the utility model, it should be noted that unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in the present utility model based on the specific circumstances.

[0024] As attached Figure 1 To be continued Figure 3 As shown:

[0025] This utility model provides an injection mold for a dust cover for an automotive steering shaft, comprising a mold support 1, an upper moving mold 2, a lower moving mold 3, a hydraulic cylinder 4, a cavity 5, a cooling water channel 6, an injection port 7, an injection head 8, a rotary head 9, a drive component 10, and injection mold cores 11. The upper moving mold 2 and the lower moving mold 3 are slidably mounted on the inner side of the mold support 1, and are respectively fixed to the output ends of the hydraulic cylinder 4 fixedly mounted on the outer side of the mold support 1. The upper moving mold 2 and the lower moving mold 3 are provided with the cavity 5, the cooling water channel 6, and the injection port 7, which corresponds to the injection head 8 mounted on the mold support 1. A plurality of injection mold cores 11 are fixedly mounted on the rotary head 9 rotatably mounted on the inner side of the mold support 1, and the rotary head 9 is fixed to the output end of the drive component 10 fixedly mounted on the outer side of the mold support 1.

[0026] Furthermore, both the upper moving mold 2 and the lower moving mold 3 are integrally formed from high-strength mold steel, and each has an independently installed cooling water channel 6. The cooling water channel 6 is arranged close to the outer wall of the cavity 5, with a distance of 3-5mm between them, which can directly and directionally cool the injection molded material in the cavity 5. The inlet of the cooling water channel 6 of the upper moving mold 2 is located on its upper side, and the outlet is located on its lower side; the inlet of the cooling water channel 6 of the lower moving mold 3 is located on its lower side, and the outlet is located on its upper side, forming an upward and downward convection cooling circulation path. The inlet and outlet of the cooling water channel 6 are connected to the external cooling water circulation system through quick-connect couplings and hoses. The couplings are equipped with nitrile rubber O-rings to ensure sealing and prevent cooling water leakage from affecting the injection molding operation. The two independent cooling water channels 6 can adjust the water flow rate and temperature (the water temperature is controlled at 20-30℃) to ensure uniform cooling of the cavity 5 area of ​​the upper moving mold 2 and the lower moving mold 3, and to avoid shrinkage or deformation of the dust cover due to local temperature differences.

[0027] Furthermore, the cavities 5 of both the upper moving mold 2 and the lower moving mold 3 are formed by electrical discharge machining (EDM), and the inner walls of the cavities 5 are mirror-polished to ensure the smoothness of the outer surface of the dust cover after molding. When the upper moving mold 2 and the lower moving mold 3 are closed under the drive of the hydraulic cylinder 4, they achieve precise docking through the guide rail that slides on the inner side of the mold support 1. High-temperature lubricating grease is applied between the mating surfaces to reduce mold closing wear. After the cavities 5 are joined, they together with the injection mold core 11 (with corresponding corrugated grooves machined on the outer surface) to form a complete corrugated dust cover injection molding cavity. The gap of the molding cavity (i.e., the wall thickness of the dust cover) is controlled within 1.2-2.0 mm according to design requirements. Meanwhile, the injection ports 7 (both semi-circular grooves) of the upper moving mold 2 and the lower moving mold 3 form a complete circular injection port after the mold is closed. The inner wall of the injection port 7 is machined with a tapered guide surface, which forms an interference fit with the injection head 8 (with a matching tapered outer surface) on the mold support 1 (fitting tolerance H7 / g6), ensuring that the molten colloid will not leak from the contact surface during injection.

[0028] Furthermore, the circular injection port 7 formed after mold closing has a diameter of 8-12mm, and its end is directly connected to the starting end of the cavity 5. The area of ​​the cavity 5 at the connection point is designated as a flow distribution area. The flow distribution area is an annular groove structure with a diameter 15-20mm larger than the injection port 7 and a depth of 5-8mm. It is located at the end face of the injection mold core 11 that penetrates into the cavity 5 (this end face of the injection mold core 11 has an arc-shaped transition structure to avoid dead corners in the flow of the molten material). When the molten material is injected from the injection head 8, it first enters the flow distribution area and stays there briefly. The volume of this area buffers the injection pressure (the pressure is controlled at 80-120MPa). Then, under the action of pressure, it flows evenly along the gap between the outer surface of the injection mold core 11 and the inner wall of the cavity 5, gradually filling the entire corrugated injection molding cavity, effectively avoiding local missing material or air bubbles caused by uneven flow of the molten material.

[0029] Furthermore, the injection mold core 11 is machined from Cr12MoV alloy tool steel with a chrome-plated surface, possessing high wear resistance and demolding properties. Its outer surface is machined with corresponding annular protrusions according to the corrugation parameters of the dust cover. The axes of several injection mold cores 11 are on the same horizontal plane. The outer end of each injection mold core 11 is fixed to the outer surface of the rotary head 9 using hexagonal socket head cap screws. A positioning step is provided at the bolt connection to ensure that the perpendicularity error between the injection mold core 11 and the rotary head 9 is ≤0.03mm. The rotary head 9 is cast from QT600-3 ductile iron, with a cross-section of an equilateral polygonal structure (such as a square, hexagon, or octagon). The included angle between the centers of two adjacent injection mold cores 11 is equal (e.g., 90° for a square). The rotary head 9 is rotatably mounted inside the mold support 1 via bearings, and is located on one side of the upper moving mold 2 and the lower moving mold 3. Its central shaft is rigidly connected to the output shaft of the drive component 10 (such as a servo motor + reducer) via a flat key, ensuring that each injection mold core 11 can accurately align with the position of the cavity 5 when the rotary head 9 rotates.

[0030] Furthermore, the upper moving mold 2 and the lower moving mold 3 are slidably guided by linear guide rails (model HGH20CA) on the inner side of the mold support 1, ensuring a smooth and non-offset opening and closing process. When the hydraulic cylinder 4 drives the upper moving mold 2 to move upward and the lower moving mold 3 to move downward, the straight-line distance between them must be strictly controlled to "the maximum diameter of the injection mold core 11 + 5-10mm safety margin". For example, when the diameter of the injection mold core 11 is 50mm, the opening and closing distance is set to 55-60mm. This distance is precisely controlled by the stroke sensor (accuracy ±0.1mm) of the hydraulic cylinder 4, ensuring that when the injection mold core 11 rotates with the rotary head 9 and passes between the upper moving mold 2 and the lower moving mold 3, it will not collide with the inner wall of the moving mold (the inner edge of the moving mold is chamfered at 5×45°), and it can also ensure that the injection mold core 11 is accurately inserted into the cavity 5 during subsequent mold closing. At the same time, this distance design provides sufficient space for the rotation of the rotary head 9, allowing the part removal operation and injection molding operation to be carried out simultaneously, improving production continuity.

[0031] The working principle is as follows: First, in the initial state, the upper moving mold 2 and the lower moving mold 3 are separated. The wheel head 9, driven by the drive component 10, rotates one of the injection mold cores 11 to the position corresponding to the cavity 5 of the upper moving mold 2 and the lower moving mold 3.

[0032] Secondly, the hydraulic cylinder 4 on the outside of the mold support 1 is activated, driving the upper moving mold 2 to move down and the lower moving mold 3 to move up, so that the two slide along the inner side of the mold support 1 and close the mold. At this time, the injection mold core 11 is inserted into the cavity 5, and together with the cavity 5, it forms the injection molding cavity of the corrugated dust cover. After the injection ports 7 of the upper moving mold 2 and the lower moving mold 3 are closed, they are connected with the injection head 8 on the mold support 1.

[0033] Next, the injection head 8 injects the molten colloid into the molding cavity through the injection port 7. The colloid first lingers briefly in the distribution area, and then flows along the gap between the injection mold core 11 and the cavity 5 until it fills the entire molding cavity.

[0034] Then, cooling water is introduced into the cooling water channel 6 to cool the colloid in the cavity 5, causing the colloid to solidify and form a dustproof cover.

[0035] Then, the hydraulic cylinder 4 drives the upper moving mold 2 to move up and the lower moving mold 3 to move down, so that the two are separated. The formed dust cover remains in the original position with the injection mold core 11. The driving component 10 drives the wheel head 9 to rotate, and rotates the injection mold core 11 with the formed dust cover out between the upper moving mold 2 and the lower moving mold 3. At the same time, the next unused injection mold core 11 is rotated to the position of the corresponding cavity 5.

[0036] Finally, the operator removes the formed dust cover from the injection mold core 11 after it is transferred out, completing one production cycle. The above steps are then repeated to achieve continuous production. The corrugated cover part formed in the diversion area is then cut.

[0037] Any technical solution that achieves the above-mentioned technical effects by utilizing the technical solution described in this utility model, or by designing a similar technical solution inspired by the technical solution described in this utility model, falls within the protection scope of this utility model.

Claims

1. An injection mold for a dust cover body for an automotive steering shaft, characterized in that, The mold includes a mold support (1), an upper moving mold (2), a lower moving mold (3), a hydraulic cylinder (4), a cavity (5), a cooling water channel (6), an injection port (7), an injection head (8), a rotary head (9), a drive component (10), and an injection mold core (11). The upper moving mold (2) and the lower moving mold (3) are slidably mounted on the inner side of the mold support (1). The upper moving mold (2) and the lower moving mold (3) are respectively fixedly mounted on the outer side of the mold support (1) with their corresponding hydraulic cylinders. 4) The output ends are fixed. The upper moving mold (2) and the lower moving mold (3) are provided with the cavity (5), cooling water channel (6) and injection port (7). The injection port (7) corresponds to the injection head (8) installed on the mold support (1). Several injection mold cores (11) are fixedly installed on the rotating head (9) rotatably installed inside the mold support (1). The output end of the rotating head (9) is fixed to the drive component (10) fixedly installed outside the mold support (1).

2. The injection mold for a dust cover for an automotive steering shaft as described in claim 1, characterized in that: The upper moving mold (2) and the lower moving mold (3) are each provided with an independent cooling water channel (6). The cooling water channel (6) is located near the cavity (5), and the upper moving mold (2) and the lower moving mold (3) are each provided with an inlet and an outlet that communicate with the cooling water channel (6).

3. The injection mold for a dust cover for an automotive steering shaft as described in claim 2, characterized in that: After the cavities (5) of the upper moving mold (2) and the lower moving mold (3) are combined together, they work together with the injection mold core (11) to form the injection molding cavity of the corrugated dust cover. After the injection ports (7) of the upper moving mold (2) and the lower moving mold (3) are combined together, they form the injection port, and the inner wall can be in close contact with the outer surface of the injection head (8) of the mold support (1).

4. The injection mold for a dust cover for an automotive steering shaft as described in claim 3, characterized in that: The injection port (7) forms an injection port that is connected to the cavity (5). The cavity (5) area near the injection port (7) is a flow diversion area. The flow diversion area is located on the end face of the injection mold core (11) that extends into the cavity (5). That is, after the colloid is retained in the flow diversion area, it flows to the injection molding cavity between the injection mold core (11) and the cavity (5).

5. The injection mold for a dust cover for an automotive steering shaft as described in claim 4, characterized in that: The axes of several injection mold cores (11) are on the same plane. One end of each injection mold core (11) is fixedly installed on the outer surface of the wheel head (9). The cross section of the wheel head (9) is an equilateral polygonal structure and is located on one side of the upper moving mold (2) and the lower moving mold (3).

6. The injection mold for a dust cover for an automotive steering shaft as described in claim 5, characterized in that: The distance between the upper moving mold (2) and the lower moving mold (3) driven apart by the hydraulic cylinder (4) allows the injection mold core (11) to pass through, that is, the straight-line distance between the upper moving mold (2) and the lower moving mold (3) is greater than the diameter of the injection mold core (11).

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