Automatic guiding and positioning mechanism of precise injection mold

Abstract

The automatic guiding and positioning mechanism comprises a bottom plate and a top plate, a lower mold and an upper mold are arranged between the bottom plate and the top plate, and a composite positioning mechanism is arranged between the bottom plate and the top plate. The composite positioning mechanism comprises a positioning guide column and a positioning guide sleeve which are fixedly installed on the surface of the upper die and the surface of the lower die respectively, a sleeve is installed in the positioning guide sleeve, the positioning guide column is installed in the sleeve in a sliding mode, and an axial thermal compensation assembly is arranged in the sleeve. The temperature of the inner cavity of the mold and the temperature of the annular groove can be stabilized and balanced through a heat balance component composed of a heat output pipe and a phase change heat storage material rod, when the temperature rises, a heat telescopic piece is pushed to drive a waveform limiting ring to deform, a positioning guide column is pressurized and stabilized, and the heat compensation effect is good. The problem that the fit clearance becomes large due to thermal expansion is effectively counteracted, and loosening of the positioning guide column and the guide sleeve is avoided.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and in particular to an automatic guiding and positioning mechanism for precision injection molds. Background Technology

[0002] With the rapid development of high-end manufacturing fields such as electronic information, automotive lightweighting, and medical devices, the market has placed stringent demands on the dimensional accuracy, surface quality, and molding stability of precision injection molded parts. The guiding and positioning mechanism of injection molds, as a core component ensuring mold opening and closing accuracy and controlling the alignment error between the cavity and core, directly determines the final quality of the injection molded parts. Currently, precision injection molds generally adopt a guiding and positioning structure using guide pillars and guide sleeves. During precision injection molding, the mold cavity temperature is typically maintained between 80-150℃, and even higher during the injection of some engineering plastics. The thermal expansion coefficients of components such as guide pillars, guide sleeves, support rings, and retainers differ. The increased mold temperature during injection molding causes fluctuations in the fit clearance between the guide pillars and guide sleeves. Excessive clearance can cause positioning loosening, while insufficient clearance can easily lead to guide pillar jamming, severely affecting the smoothness of mold opening and closing and positioning accuracy. Summary of the Invention

[0003] The purpose of this invention is to provide an automatic guiding and positioning mechanism for precision injection molds, so as to solve the problem mentioned in the background art that the increase in mold temperature during injection molding causes fluctuations in the fit clearance between the guide pillar and the guide sleeve. Excessive clearance will cause loose positioning, affecting the smoothness of mold opening and closing and the positioning accuracy.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an automatic guiding and positioning mechanism for a precision injection mold, comprising a base plate and a top plate, wherein a lower mold and an upper mold are disposed between the base plate and the top plate, and a composite positioning mechanism is disposed between the base plate and the top plate. The composite positioning mechanism includes a positioning guide post and a positioning guide sleeve respectively fixedly installed on the surfaces of the upper mold and the lower mold. A sleeve is installed inside the positioning guide sleeve, and the positioning guide post is slidably installed inside the sleeve. An axial thermal compensation component is disposed inside the sleeve, the axial thermal compensation component including a fixed plate fixedly installed inside the sleeve, an annular groove being formed inside the sleeve, and a plurality of thermal expansion members communicating with the annular groove being fixedly installed on the surface of the fixed plate. A wave-shaped limiting ring is disposed at one end of the thermal expansion member near the positioning guide post. A heat output pipe is disposed between the upper mold and the lower mold, and the heat output pipe is connected to the interior of the annular groove through a connecting pipe.

[0005] As a preferred embodiment of the present invention, a lower mold is provided at the top of the base plate and an upper mold is provided at the bottom of the top plate. The upper mold and the lower mold slide through the positioning guide post and the positioning guide sleeve, respectively. Sealing gaskets are fixedly installed on the surfaces of the lower mold and the upper mold near the positioning guide post.

[0006] As a preferred embodiment of the present invention, a pressure relief valve is provided on the connecting pipe, a heat-absorbing rod is fixedly installed inside the connecting pipe near the inner cavity of the lower mold, a heat-conducting ring for thermal compensation of the waveform limiting ring is fixedly installed inside the annular groove, and the heat-absorbing rod and the heat-conducting ring are fixedly connected, and a pressure head for reducing friction damage is fixedly installed at one end of the thermal expansion member near the waveform limiting ring.

[0007] As a preferred embodiment of the present invention, a sliding assembly is provided inside the sleeve. The sliding assembly includes a support ring installed inside the sleeve. A drive bushing is fixedly installed on the surface of the support ring near the positioning guide post. A ball bearing is rotatably installed inside the drive bushing.

[0008] As a preferred embodiment of the present invention, a movable plate is slidably installed inside the support ring, a first spring is fixedly installed between the movable plate and the inner wall of the support ring, an oil-absorbing cotton for absorbing lubricating oil is fixedly installed on the surface of the movable plate near the rolling ball, and an oil outlet channel is opened between the movable plate and the rolling ball.

[0009] As a preferred embodiment of the present invention, a rotating rod is rotatably installed inside the oil outlet channel, and the rotating rod pushes the moving plate to pressurize the oil-absorbing cotton to discharge oil through a ball bearing. A collection tank for storing waste oil is fixedly installed on the inner bottom wall of the positioning guide sleeve.

[0010] As a preferred embodiment of the present invention, the positioning guide sleeve is provided with a plurality of pressure stabilizing components. The pressure stabilizing components include an elongated groove formed in the inner bottom wall of the positioning guide sleeve, a piston is provided inside the elongated groove, a slide rod is fixedly installed inside the elongated groove and slides through the piston, a second spring is fixedly installed between the piston and the inner wall of the elongated groove, and an air groove for negative pressure exhaust is formed on the outer side of the elongated groove.

[0011] As a preferred embodiment of the present invention, an exhaust mechanism is provided between the upper mold and the lower mold. The exhaust mechanism includes an air pump fixedly installed on one side of the lower mold. An annular pipe is fixedly installed at the top of the upper mold. A stepped variable diameter exhaust pipe is connected to one end of the annular pipe near the inside of the cavity mold. The annular pipe is connected to the input end of the air pump through an air suction pipe.

[0012] As a preferred embodiment of the present invention, the heat output pipe is connected to the inside of the annular pipe, and the inside of the heat output pipe is provided with a heat balance component for balancing the temperature between the inner cavity of the injection mold and the inside of the annular groove, and the heat balance component is made of a phase change heat storage material rod.

[0013] As a preferred embodiment of the present invention, a damping spring is fixedly installed on the inner bottom wall of the positioning guide sleeve, and a rubber plate is fixedly installed on the end of the positioning guide post near the damping spring.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves dynamic positioning adjustment under temperature changes through the synergistic action of a heat output pipe, a phase change heat storage material rod forming a thermal balance component, and an axial thermal compensation assembly. The phase change heat storage material rod can stably balance the temperature of the mold cavity and the annular groove, allowing heat flow to be evenly transferred to the annular groove. When the temperature rises, it pushes the thermal expansion component to deform the waveform limiting ring, pressurizing and stabilizing the positioning guide post, effectively offsetting the problem of increased fit clearance caused by thermal expansion, and preventing the positioning guide post and guide sleeve from loosening. At the same time, the heat-conducting ring, together with the heat-absorbing rod, quickly conducts heat, further improving the uniformity of thermal compensation, solving the positioning deviation and flash defects of injection molded parts caused by thermal deformation in traditional guiding mechanisms, and is suitable for high-temperature precision injection molding.

[0015] 2. This invention uses an interference fit between the support ring and the inner wall of the guide post to effectively resist the impact of mold opening and closing and prevent axial movement of the support ring. The precision ball bearings inside the support ring, combined with the drive bushing, not only improve the guiding accuracy of the ball bearing track but also significantly reduce rolling friction loss and enhance the wear resistance of the mechanism. At the same time, this combination can withstand higher loads and temperatures. With the smooth rotation of the ball bearings, wear and deformation during the guiding process are reduced, extending the overall service life of the guiding and positioning mechanism.

[0016] 3. This invention drives the ball to rotate during the installation of the positioning guide post and the mold opening and closing process. The ball drives the rotating rod to drive the moving plate to compress the first spring, which in turn squeezes the oil-absorbing cotton to automatically release oil, providing precise lubrication for the contact surface of the ball and the positioning guide post. This achieves synchronous linkage between lubrication and mold operation, which reduces the frictional resistance between the positioning guide post and the sleeve, ensuring smooth and efficient mold opening and closing and installation processes. It also avoids component wear caused by dried-out or contaminated grease. At the same time, the collection tank can centrally store waste oil for easy subsequent cleaning.

[0017] 4. This invention effectively buffers the axial impact load generated during mold opening and closing by cooperating with the damping spring at the bottom of the positioning guide sleeve and the rubber plate at the end of the positioning guide post. This avoids deformation and damage caused by rigid collision between the guide post and the guide sleeve. At the same time, the pressure stabilizing component, through the combination structure of piston, slide rod and second spring, works with the air groove to realize negative pressure venting and pressure regulation. This can counteract the eccentric load caused by the lateral force during the injection molding and holding pressure stage, prevent the guide mechanism from shifting or wearing. Furthermore, after the positioning guide post and positioning guide sleeve are vented, a negative pressure is formed inside, which can further increase the stability between the positioning guide post and positioning guide sleeve, thereby improving the injection molding accuracy.

[0018] 5. This invention can efficiently discharge gas from the mold cavity through an air pump and a stepped variable diameter exhaust pipe, avoiding defects such as bubbles and dents in the injection molded parts and reducing blockage inside the exhaust pipe. At the same time, the heat generated during the exhaust process provides a stable heat source for the axial heat compensation component through the heat output pipe, and the sealing gasket ensures the sealing performance between the guide mechanism and the mold, preventing lubricating oil leakage and plastic debris from entering. The pressure relief valve can adjust the pressure in the annular groove to avoid excessive pressure damaging the thermal expansion component, thus improving the guiding and positioning accuracy and optimizing the injection molding effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the lower mold structure of the present invention; Figure 3 This is a schematic diagram of the sealing gasket structure of the present invention; Figure 4 This is a schematic diagram of the positioning guide sleeve structure of the present invention; Figure 5 This is a schematic diagram of the internal structure of the positioning guide sleeve of the present invention; Figure 6 This is a schematic diagram of the internal structure of the long groove of the present invention; Figure 7 This is a schematic diagram of the sleeve explosion structure of the present invention; Figure 8 This is a schematic diagram of the support ring structure of the present invention; Figure 9 This is a schematic diagram of the internal structure of the support ring of the present invention; Figure 10 This is a schematic diagram of the waveform limiting ring structure of the present invention.

[0020] In the diagram: 1. Top plate; 2. Upper mold; 3. Lower mold; 4. Base plate; 5. Composite positioning mechanism; 51. Positioning guide post; 52. Sealing gasket; 53. Positioning guide sleeve; 54. Sleeve; 55. Axial thermal compensation component; 551. Heat absorber; 552. Connecting pipe; 553. Heat conducting ring; 554. Annular groove; 555. Heat output pipe; 556. Fixing plate; 557. Wave-shaped limiting ring; 558. Pressure head; 559. Thermal expansion component; 5510. Pressure relief valve; 56. Sliding... Components; 561, support ring; 562, drive shaft sleeve; 563, ball bearing; 564, oil-absorbing cotton; 565, rotating rod; 566, moving plate; 567, first spring; 568, collection groove; 57, rubber plate; 58, damping spring; 59, pressure stabilizing component; 591, air groove; 592, slide rod; 593, piston; 594, long groove; 595, second spring; 6, exhaust mechanism; 61, annular pipe; 62, stepped variable diameter exhaust pipe; 63, intake pipe; 64, air pump. Detailed Implementation

[0021] 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.

[0022] Please see Figure 1-10 This invention provides an automatic guiding and positioning mechanism for a precision injection mold, including a base plate 4 and a top plate 1. A lower mold 3 and an upper mold 2 are disposed between the base plate 4 and the top plate 1. A composite positioning mechanism 5 is disposed between the base plate 4 and the top plate 1. The composite positioning mechanism 5 includes a positioning guide post 51 and a positioning guide sleeve 53, which are respectively fixedly installed on the surfaces of the upper mold 2 and the lower mold 3. A sleeve 54 is installed inside the positioning guide sleeve 53, and the positioning guide post 51 is slidably installed inside the sleeve 54. An axial heat compensation device is provided inside the sleeve 54. The axial thermal compensation component 55 includes a fixed plate 556 fixedly installed inside the sleeve 54. The sleeve 54 has an annular groove 554 inside. Multiple thermal expansion members 559 communicating with the annular groove 554 are fixedly installed on the surface of the fixed plate 556. A wave-shaped limiting ring 557 is provided at one end of the thermal expansion member 559 near the positioning guide post 51. A heat output pipe 555 is provided between the upper mold 2 and the lower mold 3. The heat output pipe 555 communicates with the inside of the annular groove 554 through a connecting pipe 552.

[0023] In this integral mold, the positioning guide post 51 is fixed to the upper mold 2 and the positioning guide sleeve 53 is fixed to the lower mold 3. The positioning guide post 51 is slidably embedded in the sleeve 54 inside the positioning guide sleeve 53. The sleeve 54 constrains the movement trajectory of the positioning guide post 51 to ensure the straightness of mold opening and closing. The heat output pipe 555 between the upper mold 2 and the lower mold 3 collects the heat flow around the injection cavity and transmits it to the annular groove 554 of the sleeve 54 through the connecting pipe 552. The temperature change in the annular groove 554 drives the thermal expansion member 559 to expand and contract. The thermal expansion member 559 drives the pressure head 558 to move. The pressure head 558 presses the waveform limiting ring 557 to deform, thereby forming a radial pressure limit on the positioning guide post 51 in the sleeve 54, effectively offsetting the problem of increased fit clearance caused by thermal expansion and preventing the positioning guide post 51 from loosening with the positioning guide sleeve 53. Among them, the waveform limiting ring 557 is made of shape memory alloy material. Its initial peak height is the same as the pushing displacement of the thermal expansion member 559 after it is fully extended. That is, through the reversibility of the deformation of the waveform limiting ring 557 under high temperature environment, the stable support effect on the positioning guide post 51 is increased.

[0024] In some embodiments, a lower mold 3 is provided at the top of the base plate 4, and an upper mold 2 is provided at the bottom of the top plate 1. The upper mold 2 and the lower mold 3 slide through the positioning guide post 51 and the positioning guide sleeve 53, respectively. Sealing gaskets 52 are fixedly installed on the surfaces of the lower mold 3 and the upper mold 2 near the positioning guide post 51.

[0025] The lower mold 3 fits against the top of the base plate 4, and the upper mold 2 fits against the bottom of the top plate 1, forming a stable upper and lower mold installation structure. The upper mold 2 slides through the positioning guide post 51, and the lower mold 3 slides through the positioning guide sleeve 53, making the assembly of the positioning guide post 51, the positioning guide sleeve 53 and the mold tighter, and preventing the mold from shifting and causing the guide mechanism to misalign. The sealing gaskets 52 of the upper mold 2 and the lower mold 3 near the positioning guide post 51 fit against the outer wall of the positioning guide post 51 to form a seal, blocking plastic debris and oil stains from entering the gap between the positioning guide post 51 and the positioning guide sleeve 53 during the injection molding process, improving the overall structural compactness, reducing shaking when opening and closing the mold, and strengthening the guiding stability.

[0026] In some embodiments, a pressure relief valve 5510 is provided on the connecting pipe 552, a heat-absorbing rod 551 is fixedly installed inside the connecting pipe 552 near the inner cavity of the lower mold 3, a heat-conducting ring 553 for thermal compensation of the waveform limiting ring 557 is fixedly installed inside the annular groove 554, and the heat-absorbing rod 551 and the heat-conducting ring 553 are fixedly connected, and a pressure head 558 for reducing friction damage is fixedly installed at one end of the thermal expansion member 559 near the waveform limiting ring 557.

[0027] The pressure relief valve 5510 at one end of the connecting pipe 552 is used to regulate the pressure in the annular groove 554. When excessive heat flow causes the pressure in the groove to exceed the standard, the pressure relief valve 5510 automatically opens to release pressure, preventing excessive pressure from damaging components such as the thermal expansion joint 559 and the sleeve 54. The heat-absorbing rod 551 in the connecting pipe 552 extends into the vicinity of the inner cavity of the lower mold 3, efficiently absorbing the radiant heat of the cavity and the conductive heat of the melt. Through the heat-conducting ring 553 fixedly connected to the heat-absorbing rod 551, the heat is evenly transferred to the inner wall of the annular groove 554 and the waveform limiting ring 557, so that the temperature of the waveform limiting ring 557 changes synchronously, avoiding uneven deformation caused by local temperature differences. The pressure head 558 at the end of the thermal expansion joint 559 fits against the waveform limiting ring 557, increasing the contact area between the thermal expansion joint 559 and the waveform limiting ring 557, reducing local pressure concentration, and reducing frictional damage when the waveform limiting ring 557 contacts the positioning guide post 51.

[0028] In some embodiments, a sliding assembly 56 is provided inside the sleeve 54. The sliding assembly 56 includes a support ring 561 installed inside the sleeve 54. A drive bushing 562 is fixedly installed on the surface of the support ring 561 near the positioning guide post 51. A ball bearing 563 is rotatably installed inside the drive bushing 562.

[0029] When the positioning guide post 51 slides inside the sleeve 54, the outer wall of the positioning guide post 51 contacts the ball 563, causing the ball 563 to rotate inside the drive bushing 562. This transforms the traditional sliding friction into rolling friction, reducing the resistance when the positioning guide post 51 slides. At the same time, the combined structure of the support ring 561 and the drive bushing 562 provides a stable motion track for the ball 563, preventing the ball 563 from deviating and causing a decrease in guiding accuracy.

[0030] In some embodiments, a movable plate 566 is slidably mounted inside the support ring 561, a first spring 567 is fixedly mounted between the movable plate 566 and the inner wall of the support ring 561, an oil-absorbing cotton 564 for absorbing lubricating oil is fixedly mounted on the surface of the movable plate 566 near the ball 563, and an oil outlet channel is opened between the movable plate 566 and the ball 563.

[0031] When the ball 563 rotates, it drives the moving plate 566 to slide along the inner wall of the support ring 561 through the oil outlet channel, squeezing the first spring 567. The compressed moving plate 566 squeezes the oil-absorbing cotton 564, causing the lubricating oil in the oil-absorbing cotton 564 to seep out through the oil outlet channel and be precisely applied to the surface of the ball 563 and the contact point between the ball 563 and the positioning guide post 51. This achieves automatic oil supply in conjunction with the mold opening and closing action and lubrication, eliminating the need for manual periodic application of grease, improving production efficiency, and ensuring the precise opening and closing of the mold.

[0032] In some embodiments, a rotating rod 565 is rotatably installed inside the oil outlet channel, and an eccentric cam mechanism is provided on the surface of the rotating rod 565. When the positioning guide post 51 slides and drives the ball 563 to rotate, the ball 563 drives the rotating rod 565 to rotate. The far-axis end of the eccentric cam periodically pushes the moving plate 566, causing it to overcome the elastic force of the first spring 567 and make linear displacement, thereby squeezing the oil-absorbing cotton 564 to automatically discharge oil. A collection tank 568 for storing waste oil is fixedly installed on the inner bottom wall of the positioning guide sleeve 53.

[0033] When the ball 563 rotates, it drives the rotating rod 565 to rotate synchronously. The rotating rod 565 pushes the moving plate 566 to slide towards the inner wall of the support ring 561 through rotation, which strengthens the squeezing force on the oil-absorbing cotton 564, ensures stable seepage of lubricating oil, and adapts to the lubrication needs under different mold opening and closing speeds. During the injection molding process, the waste oil formed after the lubricating oil is used drips into the collection groove 568 on the inner bottom wall of the positioning guide sleeve 53 under the action of gravity, realizing the centralized collection of waste oil and avoiding waste oil pollution.

[0034] In some embodiments, the positioning guide sleeve 53 is provided with a plurality of pressure stabilizing components 59. The pressure stabilizing components 59 include an elongated groove 594 formed in the inner bottom wall of the positioning guide sleeve 53. A piston 593 is provided inside the elongated groove 594. A slide rod 592 is fixedly installed inside the elongated groove 594 and slides through the piston 593. A second spring 595 is fixedly installed between the piston 593 and the inner wall of the elongated groove 594. An air groove 591 for negative pressure exhaust is formed on the outer side of the elongated groove 594.

[0035] During the injection molding and holding pressure stage, the lateral pressure generated acts on the positioning guide sleeve 53, pushing the piston 593 to move and compressing or stretching the second spring 595. At this time, the piston 593 moves and exhausts air through the air groove 591, and the elastic deformation of the second spring 595 offsets the lateral pressure. At the same time, after the positioning guide post 51 and the positioning guide sleeve 53 are installed and the air is exhausted, a negative pressure is formed inside, making the connection between the positioning guide post 51 and the positioning guide sleeve 53 more stable, thereby improving the injection molding accuracy.

[0036] In some embodiments, an exhaust mechanism 6 is provided between the upper mold 2 and the lower mold 3. The exhaust mechanism 6 includes an air pump 64 fixedly installed on one side of the lower mold 3. An annular pipe 61 is fixedly installed on the top of the upper mold 2. A stepped variable diameter exhaust pipe 62 is connected to one end of the annular pipe 61 near the inside of the cavity. The annular pipe 61 is connected to the input end of the air pump 64 through an air suction pipe 63.

[0037] Among them, the air pump 64 is connected to the annular pipe 61 at the top of the upper mold 2 through the suction pipe 63. At this time, the air pump 64 draws air from the inside of the annular pipe 61 to discharge the excess gas generated during the injection molding process and improve the precision of the injection molded parts. The end of the annular pipe 61 near the inside of the cavity mold is connected to the stepped variable diameter exhaust pipe 62. The stepped structure can prevent the injection molten metal from entering the exhaust pipe, ensuring smooth exhaust and avoiding defects such as bubbles and depressions in the injection molded parts.

[0038] In some embodiments, the heat output pipe 555 is connected to the interior of the annular pipe 61, and the interior of the heat output pipe 555 is provided with a heat balancing component for balancing the temperature between the inner cavity of the injection mold and the interior of the annular groove 554, and the heat balancing component is made of a phase change heat storage material rod.

[0039] The heat output pipe 555 is connected to the inside of the annular pipe 61. During the exhaust process, the annular pipe 61 collects some of the cavity heat. When the heat flow is transferred through the heat output pipe 555, it flows through the phase change heat storage material rod inside. The phase change heat storage material rod utilizes the phase change characteristics to absorb and store heat when the temperature is too high and release heat when the temperature is too low, balancing the temperature difference between the mold cavity and the annular groove 554. This allows the heat flow to be stably and evenly transferred to the inside of the annular groove 554, providing a stable temperature environment for the axial heat compensation component 55, ensuring the accuracy of heat compensation, and further optimizing the stability of the positioning guide post 51.

[0040] In some embodiments, a damping spring 58 is fixedly installed on the inner bottom wall of the positioning guide sleeve 53, and a rubber plate 57 is fixedly installed on one end of the positioning guide post 51 near the damping spring 58.

[0041] When the mold is closed, the rubber plate 57 at the end of the positioning guide post 51 contacts the damping spring 58. The damping spring 58 is compressed to generate an elastic reaction force, which buffers the axial impact force of the positioning guide post 51 on the positioning guide sleeve 53, effectively weakens the impact load of mold opening and closing, prevents the ends of the positioning guide post 51 and the positioning guide sleeve 53 from being deformed and damaged, and reduces the dimensional deviation of the injection molded part.

[0042] Working principle: In this integral mold, the base plate 4 and top plate 1 provide installation support for the entire mold. The upper mold 2 and lower mold 3 are closed to form a cavity. The positioning guide post 51 is fixed to the upper mold 2, and the positioning guide sleeve 53 is fixed to the lower mold 3. The positioning guide post 51 slides into the sleeve 54 inside the positioning guide sleeve 53. The sleeve 54 constrains the movement trajectory of the positioning guide post 51, ensuring the straightness of mold opening and closing. The heat output pipe 555 between the upper mold 2 and the lower mold 3 collects the heat flow around the injection cavity and transmits it to the connecting pipe 552. Within the annular groove 554 of the sleeve 54, temperature changes drive the thermal expansion member 559 to expand and contract. The thermal expansion member 559 moves the pressure head 558, which in turn deforms the waveform limiting ring 557. This creates radial pressure and limit on the positioning guide post 51 within the sleeve 54, effectively counteracting the increased clearance caused by thermal expansion. This prevents the positioning guide post 51 from loosening with the positioning guide sleeve 53, increases the stability between the positioning guide post 51 and the positioning guide sleeve 53, and thus improves the injection molding accuracy.

[0043] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. An automatic guiding and positioning mechanism for a precision injection mold, comprising a base plate (4) and a top plate (1), characterized in that: A lower mold (3) and an upper mold (2) are provided between the bottom plate (4) and the top plate (1). A composite positioning mechanism (5) is provided between the bottom plate (4) and the top plate (1). The composite positioning mechanism (5) includes a positioning guide post (51) and a positioning guide sleeve (53) respectively fixedly installed on the surfaces of the upper mold (2) and the lower mold (3). A sleeve (54) is installed inside the positioning guide sleeve (53), and the positioning guide post (51) is slidably installed inside the sleeve (54). An axial heat compensation component (55) is provided inside the sleeve (54). The axial heat compensation component (55) includes components fixedly installed on the sleeve. The sleeve (54) has a fixed plate (556) inside the cylinder (54), and an annular groove (554) is provided inside the sleeve (54). Multiple thermal expansion members (559) communicating with the annular groove (554) are fixedly installed on the surface of the fixed plate (556). A waveform limiting ring (557) is provided at one end of the thermal expansion member (559) near the positioning guide post (51). A heat output pipe (555) communicating with the inside of the annular groove (554) through a connecting pipe (552) is provided between the upper mold (2) and the lower mold (3). A heat balance component made of phase change heat storage material rod is provided inside the heat output pipe (555).

2. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: The bottom plate (4) is provided with a lower mold (3) at the top and the top plate (1) is provided with an upper mold (2) at the bottom. The upper mold (2) and the lower mold (3) slide through the positioning guide post (51) and the positioning guide sleeve (53) respectively. The surfaces of the lower mold (3) and the upper mold (2) near the positioning guide post (51) are fixedly installed with sealing gaskets (52).

3. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: A pressure relief valve (5510) is provided on the connecting pipe (552). A heat-absorbing rod (551) is fixedly installed inside the connecting pipe (552) near the inner cavity of the lower mold (3). A heat-conducting ring (553) for thermal compensation of the waveform limiting ring (557) is fixedly installed inside the annular groove (554). The heat-absorbing rod (551) and the heat-conducting ring (553) are fixedly connected. A pressure head (558) for reducing friction damage is fixedly installed at one end of the thermal expansion member (559) near the waveform limiting ring (557).

4. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: The sleeve (54) is provided with a sliding assembly (56), which includes a support ring (561) installed inside the sleeve (54). A drive bushing (562) is fixedly installed on the surface of the support ring (561) near the positioning guide post (51). A ball bearing (563) is rotatably installed inside the drive bushing (562).

5. The automatic guiding and positioning mechanism for a precision injection mold according to claim 4, characterized in that: A movable plate (566) is slidably installed inside the support ring (561). A first spring (567) is fixedly installed between the movable plate (566) and the inner wall of the support ring (561). An oil-absorbing cotton (564) for absorbing lubricating oil is fixedly installed on the surface of the movable plate (566) near the ball (563). An oil outlet channel is opened between the movable plate (566) and the ball (563).

6. The automatic guiding and positioning mechanism for a precision injection mold according to claim 5, characterized in that: The oil outlet channel is internally mounted with a rotating rod (565), and the rotating rod (565) pushes the moving plate (566) to pressurize the oil-absorbing cotton (564) to discharge oil through the ball (563). The inner bottom wall of the positioning guide sleeve (53) is fixedly mounted with a collection tank (568) for storing waste oil.

7. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: The positioning guide sleeve (53) is provided with a plurality of pressure stabilizing components (59). The pressure stabilizing components (59) include a long groove (594) opened in the bottom wall of the positioning guide sleeve (53). A piston (593) is provided inside the long groove (594). A slide rod (592) is fixedly installed inside the long groove (594) and slides through the piston (593). A second spring (595) is fixedly installed between the piston (593) and the inner wall of the long groove (594). An air groove (591) for negative pressure exhaust is opened on the outer side of the long groove (594).

8. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: An exhaust mechanism (6) is provided between the upper mold (2) and the lower mold (3). The exhaust mechanism (6) includes an air pump (64) fixedly installed on one side of the lower mold (3). An annular pipe (61) is fixedly installed at the top of the upper mold (2). A stepped variable diameter exhaust pipe (62) is connected to one end of the annular pipe (61) near the inside of the cavity. The annular pipe (61) is connected to the input end of the air pump (64) through an air suction pipe (63).

9. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: The waveform limiting ring (557) is made of shape memory alloy, and its initial peak height is the same as the pushing displacement of the thermal expansion member (559) after it is fully extended.

10. The automatic guiding and positioning mechanism for a precision injection mold according to claim 1, characterized in that: A damping spring (58) is fixedly installed on the inner bottom wall of the positioning guide sleeve (53), and a rubber plate (57) is fixedly installed on one end of the positioning guide post (51) near the damping spring (58).

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