An automatic guiding and positioning mechanism of a precision injection mold

Abstract

The application discloses an automatic guiding and positioning mechanism of a precision injection mold, which 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, a composite positioning mechanism is arranged between the bottom plate and the top plate, the composite positioning mechanism comprises positioning guide columns and positioning guide sleeves which are respectively fixedly installed on surfaces of the upper mold and the lower mold, a sleeve is installed in the positioning guide sleeve, the positioning guide column is slidingly installed in the sleeve, an axial thermal compensation assembly is arranged in the sleeve, and the axial thermal compensation assembly comprises a fixed plate which is fixedly installed in the sleeve. The heat balance component composed of the heat output pipe and the phase change heat storage material rod can stably balance the temperature of the mold cavity and the annular groove, the heat expansion component is pushed to drive the wave-shaped limiting ring to deform when the temperature rises, the positioning guide column is pressurized and stabilized, the problem that the matching gap becomes large due to thermal expansion is effectively offset, and the positioning guide column and the guide sleeve are prevented from loosening.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of injection mold, in particular to an automatic guiding and positioning mechanism of a precision injection mold. BACKGROUND

[0002] With the rapid development of high-end manufacturing fields such as electronic information, automobile lightweight, medical devices, the market puts forward strict requirements on the dimensional accuracy, surface quality and forming stability of precision injection molded parts. The guiding and positioning mechanism of the injection mold is the core component to ensure the mold opening and closing precision and control the centering error of the cavity and core, and its performance directly determines the final quality of the injection molded part. At present, the guiding and positioning structure of guide pillar and guide sleeve is generally used in precision injection mold. During the precision injection molding process, the temperature of the mold cavity is usually maintained at 80-150℃, and the temperature of the cavity is even higher when some engineering plastics are injected. However, there are differences in the thermal expansion coefficients of the guide pillar, guide sleeve, support ring and retainer, and the temperature rise of the mold during the injection molding process will cause the fluctuation of the fitting gap between the guide pillar and the guide sleeve. If the gap is too large, the positioning will be loose, and if the gap is too small, the guide pillar will be easily stuck, which will seriously affect the smoothness and positioning accuracy of the mold opening and closing. SUMMARY

[0003] The purpose of the present application is to provide an automatic guiding and positioning mechanism of a precision injection mold to solve the problem that the temperature rise of the mold during the injection molding process will cause the fluctuation of the fitting gap between the guide pillar and the guide sleeve, and the gap is too large to cause the positioning to be loose, which affects the smoothness and positioning accuracy of the mold opening and closing.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme: an automatic guiding and positioning mechanism of a precision injection mold, comprising a bottom plate and a top plate, a lower mold and an upper mold are arranged between the bottom plate and the top plate, a composite positioning mechanism is arranged between the bottom plate and the top plate, the composite positioning mechanism comprises positioning guide pillars and positioning guide sleeves fixedly installed on the surfaces of the upper mold and the lower mold respectively, a sleeve is installed in the inside of the positioning guide sleeve, and the positioning guide pillar is slidingly installed in the inside of the sleeve, an axial thermal compensation assembly is arranged in the inside of the sleeve, the axial thermal compensation assembly comprises a fixed plate fixedly installed in the inside of the sleeve, a ring-shaped groove is formed in the inside of the sleeve, a plurality of thermal expansion pieces are fixedly installed on the surface of the fixed plate and communicated with the ring-shaped groove, a wave-shaped limiting ring is arranged on the end of the thermal expansion piece close to the positioning guide pillar, a heat output pipe is arranged between the upper mold and the lower mold, and the heat output pipe is communicated with the inside of the ring-shaped groove through a connecting pipe.

[0005] As a preferred technical scheme of the present application, the top end of the bottom plate is provided with a lower mold, the bottom end of the top plate is provided with an upper mold, the upper mold and the lower mold slidingly penetrate the positioning guide pillars and the positioning guide sleeves respectively, and the surfaces of the lower mold and the upper mold close to the positioning guide pillars are fixedly installed with sealing gaskets.

[0006] As a preferred technical scheme of the present application, the connecting pipe is fixedly installed with a heat absorption rod near the inner cavity of the lower mold, the inside of the annular groove is fixedly installed with a heat conduction ring for heat compensation of the wave-shaped limiting ring, and the heat absorption rod is fixedly connected with the heat conduction ring.

[0007] As a preferred technical scheme of the present application, the inside of the sleeve is provided with a sliding assembly, the sliding assembly comprises a supporting ring installed in the inside of the sleeve, a driving shaft sleeve is fixedly installed on the surface of the supporting ring near the positioning guide column, and a rolling ball is rotatably installed in the inside of the driving shaft sleeve.

[0008] As a preferred technical scheme of the present application, the inside of the supporting ring is slidably installed with a moving plate, a first spring is fixedly installed between the moving plate and the inner wall of the supporting ring, oil absorption cotton for absorbing lubricating oil is fixedly installed on the surface of the moving plate near the rolling ball, and an oil outlet channel is formed between the moving plate and the rolling ball.

[0009] As a preferred technical scheme of the present application, a rotating rod is rotatably installed in the inside of the oil outlet channel, and the rotating rod pushes the moving plate to press the oil absorption cotton to discharge oil, and a collecting groove for storing waste oil is fixedly installed on the inner bottom wall of the positioning guide sleeve.

[0010] As a preferred technical scheme of the present application, the inside of the positioning guide sleeve is provided with a plurality of pressure stabilizing assemblies, the pressure stabilizing assemblies comprise a long groove formed in the inner bottom wall of the positioning guide sleeve, a piston is arranged in the inside of the long groove, a sliding rod is fixedly installed in the inside of the long groove, and the sliding rod slidably penetrates the piston, a second spring is fixedly installed between the piston and the inner wall of the long groove, and a gas groove for negative pressure exhaust is formed on the outside of the long groove.

[0011] As a preferred technical scheme of the present application, an exhaust mechanism is arranged between the upper mold and the lower mold, the exhaust mechanism comprises a gas pump fixedly installed on one side of the lower mold, an annular pipeline is fixedly installed at the top end of the upper mold, a stepped variable-diameter exhaust pipe is communicatively installed at one end of the annular pipeline near the inside of the concave mold, and the annular pipeline is in communication with the input end of the gas pump through a suction pipe.

[0012] As a preferred technical scheme of the present application, the heat output pipe is in communication with the inside of the annular pipeline, and a heat balance component for balancing the temperature between the inner cavity of the injection mold and the inside of the annular groove is arranged in the inside of the heat output pipe, and the heat balance component is composed of a phase change heat storage material rod.

[0013] As a preferred technical scheme of the present application, the inner bottom wall of the positioning guide sleeve is fixedly installed with a damping spring, and the end of the positioning guide column close to the damping spring is fixedly installed with a rubber plate.

[0014] Compared with the prior art, the present application has the following advantages:

[0015] 1. The heat balance component composed of the heat output pipe and the phase change heat storage material rod and the axial heat compensation assembly cooperate to realize dynamic positioning adjustment under temperature change. The phase change heat storage material rod can stabilize the temperature of the inner cavity of the mold and the annular groove, so that the heat flow is uniformly transmitted to the annular groove. When the temperature rises, the thermal expansion element is pushed to drive the wave-shaped limiting ring to deform, pressurize and stabilize the positioning guide column, effectively offset the problem of increased gap caused by thermal expansion, and avoid loosening of the positioning guide column and the guide sleeve. At the same time, the heat conduction ring cooperates with the heat absorbing rod to quickly conduct heat, further improving the uniformity of heat compensation, solving the positioning deviation and injection molding defects such as flash caused by thermal deformation of the traditional guide mechanism, and adapting to high-temperature precision injection molding.

[0016] 2. The support ring and the inner wall of the guide column are in interference fit, which can effectively resist the impact of mold opening and closing, prevent the axial movement of the support ring, and the precise ball inside the support ring is matched with the drive shaft sleeve, which not only improves the guiding accuracy of the steel ball track, but also significantly reduces the rolling friction loss and enhances the wear resistance of the mechanism. At the same time, this matching can withstand higher load and temperature, and cooperate with the smooth rotation of the ball to reduce wear and deformation during guiding, prolonging the overall service life of the guiding positioning mechanism.

[0017] 3. The positioning guide column drives the ball to rotate during installation and mold opening and closing, the ball drives the rotating rod to drive the moving plate to compress the first spring, and then squeezes the oil-absorbing cotton to automatically discharge oil, providing precise lubrication for the contact surface of the ball and the positioning guide column, realizing synchronous linkage of lubrication and mold action, reducing the friction resistance between the positioning guide column and the sleeve, ensuring smooth and efficient mold opening and closing and installation process, avoiding component wear caused by dry or contaminated lubricating grease, and the collection groove can store waste oil for subsequent cleaning.

[0018] 4. The damping spring at the bottom of the positioning guide sleeve and the rubber plate at the end of the positioning guide column cooperate with each other, which can effectively buffer the axial impact load generated during mold opening and closing, avoid deformation and damage caused by rigid collision between the guide column and the guide sleeve, and the combination structure of the piston, the slide rod and the second spring cooperates with the air groove to realize negative pressure exhaust and pressure regulation, which can offset the influence of lateral force on the positioning guide mechanism during injection molding, prevent the guide mechanism from deviating or wearing, and after the positioning guide column and the positioning guide sleeve are installed and exhausted, a negative pressure is formed inside, which can further increase the stability between the positioning guide column and the positioning guide sleeve, thereby improving the injection molding precision.

[0019] 5、 The application can efficiently discharge the gas in the cavity of the mold through the air pump and the stepped variable-diameter exhaust pipe, avoid the defects such as bubbles and depressions of the injection molded part, and reduce the blockage inside the exhaust pipe, the heat flow generated during the exhaust process provides a stable heat source for the axial thermal compensation assembly through the heat output pipe, the sealing gasket guarantees the sealing performance of the guide mechanism and the mold, prevents the lubricating oil from leaking and plastic debris from entering, the pressure relief valve can adjust the pressure in the annular groove, avoids damaging the thermal expansion component due to excessive pressure, improves the positioning accuracy of the guide, and optimizes the injection molding effect. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the application;

[0021] Figure 2 is a schematic diagram of the lower mold structure of the application;

[0022] Figure 3 is a schematic diagram of the sealing gasket structure of the application;

[0023] Figure 4 is a schematic diagram of the positioning guide sleeve structure of the application;

[0024] Figure 5 is a schematic diagram of the internal structure of the positioning guide sleeve of the application;

[0025] Figure 6 is a schematic diagram of the internal structure of the long groove of the application;

[0026] Figure 7 is a schematic diagram of the sleeve explosion structure of the application;

[0027] Figure 8 is a schematic diagram of the support ring structure of the application;

[0028] Figure 9 is a schematic diagram of the internal structure of the support ring of the application;

[0029] Figure 10 is a schematic diagram of the wave-shaped limiting ring structure of the application.

[0030] In the figure: 1, top plate; 2, upper mold; 3, lower mold; 4, bottom plate; 5, composite positioning mechanism; 51, positioning guide column; 52, sealing washer; 53, positioning guide sleeve; 54, sleeve; 55, axial thermal compensation assembly; 551, heat absorbing rod; 552, connecting pipe; 553, heat conducting ring; 554, annular groove; 555, heat output pipe; 556, fixed plate; 557, wave-shaped limiting ring; 558, pressurizing head; 559, thermal expansion piece; 5510, pressure relief valve; 56, sliding assembly; 561, support ring; 562, drive shaft sleeve; 563, rolling ball; 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 assembly; 591, air groove; 592, sliding rod; 593, piston; 594, long groove; 595, second spring; 6, exhaust mechanism; 61, annular pipeline; 62, stepped variable-diameter exhaust pipe; 63, air suction pipe; 64, air pump. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] Please refer to Figures 1-10 The present application provides an automatic guiding and positioning mechanism of a precision injection mold, which comprises a bottom plate 4 and a top plate 1, a lower mold 3 and an upper mold 2 are arranged between the bottom plate 4 and the top plate 1, a composite positioning mechanism 5 is arranged between the bottom plate 4 and the top plate 1, the composite positioning mechanism 5 comprises positioning guide columns 51 and positioning guide sleeves 53 fixedly installed on the surfaces of the upper mold 2 and the lower mold 3 respectively, a sleeve 54 is installed in the inside of the positioning guide sleeve 53, the positioning guide column 51 is slidingly installed in the inside of the sleeve 54, an axial thermal compensation assembly 55 is arranged in the inside of the sleeve 54, the axial thermal compensation assembly 55 comprises a fixed plate 556 fixedly installed in the inside of the sleeve 54, an annular groove 554 is formed in the inside of the sleeve 54, a plurality of thermal expansion pieces 559 in communication with the annular groove 554 are fixedly installed on the surface of the fixed plate 556, a wave-shaped limiting ring 557 is arranged at the end of the thermal expansion piece 559 close to the positioning guide column 51, a heat output pipe 555 is arranged between the upper mold 2 and the lower mold 3, and the heat output pipe 555 is in communication with the inside of the annular groove 554 through a connecting pipe 552.

[0033] Wherein, in the overall mold, the positioning guide pillar 51 is fixed to the upper mold 2, the positioning guide sleeve 53 is fixed to the lower mold 3, the positioning guide pillar 51 is slidingly embedded in the sleeve 54 inside the positioning guide sleeve 53, the movement track of the positioning guide pillar 51 is constrained through the sleeve 54, the straightness of mold opening and closing is ensured, the heat output pipe 555 between the upper mold 2 and the lower mold 3 collects the heat flow around the injection cavity, is transmitted 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 and contraction component 559 to expand and contract, the thermal expansion and contraction component 559 drives the pressurizing head 558 to move, the pressurizing head 558 drives the wave-shaped limiting ring 557 to deform, thereby forming radial pressurizing limiting for the positioning guide pillar 51 in the sleeve 54, effectively offsetting the problem that the matching gap becomes larger due to thermal expansion, and avoiding loosening of the positioning guide pillar 51 and the positioning guide sleeve 53.

[0034] Wherein, the wave-shaped limiting ring 557 is made of shape memory alloy material, the initial wave peak height of the wave-shaped limiting ring 557 is the same as the pushing displacement after the thermal expansion and contraction component 559 is fully stretched, that is, through the reversibility of the deformation of the wave-shaped limiting ring 557 in a high-temperature environment, thereby increasing the stable support effect on the positioning guide pillar 51.

[0035] In some embodiments, the top end of the bottom plate 4 is provided with the lower mold 3, the bottom end of the top plate 1 is provided with the upper mold 2, the upper mold 2 and the lower mold 3 are slidingly penetrated through the positioning guide pillar 51 and the positioning guide sleeve 53 respectively, and the lower mold 3 and the upper mold 2 are fixedly installed with sealing gaskets 52 close to the surface of the positioning guide pillar 51.

[0036] Wherein, the lower mold 3 is attached to the top end of the bottom plate 4, and the upper mold 2 is attached to the bottom end of the top plate 1, forming a stable upper and lower mold installation structure; the upper mold 2 is slidingly penetrated through the positioning guide pillar 51, and the lower mold 3 is slidingly penetrated through the positioning guide sleeve 53, so that the positioning guide pillar 51 and the positioning guide sleeve 53 are more closely assembled with the mold, avoiding misplacement of the guiding mechanism caused by mold deviation; the sealing gaskets 52 close to the positioning guide pillar 51 of the upper mold 2 and the lower mold 3 are attached to the outer wall of the positioning guide pillar 51 to form a seal, blocking the entry of plastic debris and oil stains into the matching gap between the positioning guide pillar 51 and the positioning guide sleeve 53 during the injection molding process, improving the compactness of the overall structure, reducing the shaking during mold opening and closing, and strengthening the guiding stability.

[0037] In some embodiments, the connecting pipe 552 is provided with a pressure relief valve 5510, the connecting pipe 552 is fixedly installed with a heat absorbing rod 551 inside the inner cavity of the lower mold 3, the annular groove 554 is fixedly installed with a heat conducting ring 553 for heat compensation of the wave-shaped limiting ring 557, and the heat absorbing rod 551 and the heat conducting ring 553 are fixedly connected, and the thermal expansion and contraction component 559 is fixedly installed with a pressurizing head 558 for reducing friction damage at one end close to the wave-shaped limiting ring 557.

[0038] The pressure relief valve 5510 at one end of the connecting pipe 552 is used to adjust the pressure in the annular groove 554, and when the heat is too much to cause the pressure in the groove to exceed the standard, the pressure relief valve 5510 is automatically opened to release pressure, so as to avoid damage to the thermal expansion piece 559, the sleeve 54 and other components due to excessive pressure. The heat-absorbing rod 551 in the connecting pipe 552 extends to the vicinity of the inner cavity of the lower mold 3, efficiently absorbs the radiation heat and conduction heat of the cavity, and uniformly transmits the heat to the inner wall of the annular groove 554 and the wave-shaped limiting ring 557 through the heat-conducting ring 553 fixedly connected with the heat-absorbing rod 551, so that the temperature of the wave-shaped limiting ring 557 changes synchronously, and deformation caused by local temperature difference is avoided. The pressurizing head 558 at the end of the thermal expansion piece 559 is attached to the wave-shaped limiting ring 557, which increases the contact area of the thermal expansion piece 559 and the wave-shaped limiting ring 557, reduces local pressure concentration, and reduces the friction damage of the wave-shaped limiting ring 557 when it is in contact with the positioning guide column 51.

[0039] In some embodiments, the inside of the sleeve 54 is provided with a sliding assembly 56, which includes a support ring 561 mounted in the inside of the sleeve 54, a driving shaft sleeve 562 fixedly mounted on the surface of the support ring 561 close to the positioning guide column 51, and a rolling ball 563 rotatably mounted in the inside of the driving shaft sleeve 562.

[0040] When the positioning guide column 51 slides in the sleeve 54, the outer wall of the positioning guide column 51 is in contact with the rolling ball 563, which drives the rolling ball 563 to rotate in the driving shaft sleeve 562, converts the traditional sliding friction into rolling friction, reduces the resistance when the positioning guide column 51 slides, and at the same time, the combined structure of the support ring 561 and the driving shaft sleeve 562 provides a stable motion track for the rolling ball 563, preventing the rolling ball 563 from deviating and causing a decrease in guiding accuracy.

[0041] In some embodiments, a moving plate 566 is slidably mounted in the inside of the support ring 561, a first spring 567 is fixedly mounted between the moving 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 moving plate 566 close to the rolling ball 563, and an oil outlet channel is formed between the moving plate 566 and the rolling ball 563.

[0042] When the rolling ball 563 rotates, the moving plate 566 is driven to slide along the inner wall of the support ring 561 through the oil outlet channel, extruding the first spring 567, and the extruded moving plate 566 extrudes the oil-absorbing cotton 564, so that the lubricating oil in the oil-absorbing cotton 564 seeps out through the oil outlet channel and is precisely applied to the surface of the rolling ball 563 and the contact position of the rolling ball 563 and the positioning guide column 51, realizing the linkage of the mold opening and closing action and the lubrication, and eliminating the need for manual periodic application of lubricating grease, thereby improving production efficiency and ensuring the precise opening and closing of the mold.

[0043] In some embodiments, the inner rotation of the oil outlet channel is rotationally mounted with a rotating rod 565, and the surface of the rotating rod 565 is provided with an eccentric cam mechanism. When the positioning guide column 51 slides to drive the rotation of the rolling ball 563, the rolling ball 563 drives the rotation of the rotating rod 565. The far shaft end of the eccentric cam periodically pushes the moving plate 566 to overcome the elastic force of the first spring 567 to move linearly, thereby extruding the oil absorption cotton 564 to automatically discharge oil. The inner bottom wall of the positioning guide sleeve 53 is fixedly installed with a collecting groove 568 for storing waste oil.

[0044] Wherein, the rolling ball 563 rotates to drive the rotating rod 565 to rotate synchronously, the rotating rod 565 pushes the moving plate 566 to slide towards the inner wall of the supporting ring 561 by rotating, strengthens the extrusion force on the oil absorption cotton 564, ensures the stable seepage of lubricating oil, and adapts to the lubrication demand under different mold opening and closing speeds; during the injection molding process, the waste oil formed after the use of lubricating oil drops to the collecting groove 568 in the inner bottom wall of the positioning guide sleeve 53 under the action of gravity, realizes the centralized storage of waste oil, and avoids the pollution of waste oil.

[0045] In some embodiments, the inside of the positioning guide sleeve 53 is provided with a plurality of pressure stabilizing components 59. The pressure stabilizing component 59 includes a long slot 594 opened in the inner bottom wall of the positioning guide sleeve 53. The inside of the long slot 594 is provided with a piston 593. The inside of the long slot 594 is fixedly installed with a sliding rod 592, and the sliding rod 592 slides through the piston 593. The piston 593 and the inner wall of the long slot 594 are fixedly installed with a second spring 595. The outside of the long slot 594 is provided with a gas slot 591 for negative pressure exhaust.

[0046] Wherein, when the lateral pressure generated in the injection pressure maintaining stage acts on the positioning guide sleeve 53, the piston 593 moves and compresses or stretches the second spring 595. At this time, the piston 593 moves through the gas slot 591 to exhaust, and the elastic deformation of the second spring 595 offsets the lateral pressure. At the same time, after the positioning guide column 51 and the positioning guide sleeve 53 are installed and exhausted, a negative pressure is formed inside, so that the connection between the positioning guide column 51 and the positioning guide sleeve 53 is more stable, thereby improving the injection molding precision.

[0047] In some embodiments, an exhaust mechanism 6 is arranged between the upper die 2 and the lower die 3. The exhaust mechanism 6 includes a gas pump 64 fixedly installed on one side of the lower die 3. The top end of the upper die 2 is fixedly installed with an annular pipeline 61. The end of the annular pipeline 61 close to the inside of the concave die is communicatedly installed with a stepped variable-diameter exhaust pipe 62. The annular pipeline 61 is communicated with the input end of the gas pump 64 through a suction pipe 63.

[0048] Wherein, the air pump 64 is communicated with the annular pipeline 61 at the top end of the upper mold 2 through the suction pipe 63, at this time, the air pump 64 pumps the air in the annular pipeline 61, discharges the excess gas generated in the injection molding process, and improves the precision of the injection molded part; the annular pipeline 61 is communicated with the stepped variable-diameter exhaust pipe 62 at one end close to the inside of the concave mold, the stepped structure can prevent the injection melt from entering the exhaust pipe, ensure smooth exhaust, and avoid defects such as bubbles and depressions in the injection molded part.

[0049] In some embodiments, the heat output pipe 555 is communicated with the inside of the annular pipeline 61, and the inside of the heat output pipe 555 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 554, and the heat balance component is composed of a phase change heat storage material rod.

[0050] Wherein, the heat output pipe 555 is communicated with the inside of the annular pipeline 61, and the annular pipeline 61 collects part of the cavity heat during the exhaust process, and the heat flow passes through the phase change heat storage material rod inside the heat output pipe 555 when transmitting; the phase change heat storage material rod uses the phase change characteristics to absorb heat when the temperature is too high and release heat when the temperature is too low, balances the temperature difference between the inner cavity of the mold and the annular groove 554, and makes the heat flow stable and uniform to the inside of the annular groove 554, provides a stable temperature environment for the axial thermal compensation assembly 55, guarantees the thermal compensation precision, and further optimizes the stability effect of the positioning guide column 51.

[0051] In some embodiments, the inner bottom wall of the positioning guide sleeve 53 is fixedly installed with a damping spring 58, and one end of the positioning guide column 51 close to the damping spring 58 is fixedly installed with a rubber plate 57.

[0052] Wherein, when the mold is in place, the rubber plate 57 at the end of the positioning guide column 51 is in contact with 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 column 51 on the positioning guide sleeve 53, effectively weakens the mold opening and closing impact load, prevents the deformation and damage of the end of the positioning guide column 51 and the positioning guide sleeve 53, and reduces the size deviation of the injection molded part.

[0053] Working principle: in the integral mold, the bottom plate 4 and the top plate 1 provide installation support for the mold as a whole, the upper mold 2 and the lower mold 3 correspond to the mold to form a cavity, the positioning guide column 51 is fixed on the upper mold 2, the positioning guide sleeve 53 is fixed on the lower mold 3, the positioning guide column 51 is slidably embedded in the sleeve 54 inside the positioning guide sleeve 53, the movement track of the positioning guide column 51 is constrained through the sleeve 54, the linear degree of mold opening and closing is guaranteed, the heat output pipe 555 between the upper mold 2 and the lower mold 3 collects the heat flow around the injection cavity, is transmitted 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 and contraction member 559 to expand and contract, the thermal expansion and contraction member 559 drives the pressurizing head 558 to move, the pressurizing head 558 presses the wave-shaped limiting ring 557 to deform, thereby forming radial pressurizing limiting for the positioning guide column 51 in the sleeve 54, effectively offsetting the problem that the matching gap becomes larger due to thermal expansion, avoiding loosening of the positioning guide column 51 and the positioning guide sleeve 53, increasing the stability effect between the positioning guide column 51 and the positioning guide sleeve 53, thereby improving the injection molding precision.

[0054] The above is only a specific embodiment of the present application, but the technical features of the present application are not limited thereto. Any simple change, equivalent replacement or modification made on the basis of the present application to solve the basically same technical problem and realize the basically same technical effect is covered in the protection scope of the present application.

Claims

1. An automatic guiding positioning mechanism of a precision injection mold comprising a base plate (4) and a top plate (1), characterized in that: The bottom plate (4) and the top plate (1) are provided with a lower mold (3) and an upper mold (2), and a composite positioning mechanism (5) is arranged between the bottom plate (4) and the top plate (1), the composite positioning mechanism (5) comprises positioning guide columns (51) and positioning guide sleeves (53) fixedly installed on the surfaces of the upper mold (2) and the lower mold (3) respectively, a sleeve (54) is installed in the positioning guide sleeve (53), the positioning guide column (51) is slidingly installed in the sleeve (54), an axial thermal compensation assembly (55) is arranged in the sleeve (54), the axial thermal compensation assembly (55) comprises a fixed plate (556) fixedly installed in the sleeve (54), a ring-shaped groove (554) is formed in the sleeve (54), a plurality of thermal expansion elements (559) are fixedly installed on the surface of the fixed plate (556) and communicate with the ring-shaped groove (554), a wave-shaped limiting ring (557) is arranged at one end of the thermal expansion element (559) close to the positioning guide column (51), a heat output pipe (555) in communication with the inside of the ring-shaped groove (554) through a connecting pipe (552) is arranged between the upper mold (2) and the lower mold (3), and the heat output pipe (555) is provided with a heat balance component composed of a phase change heat storage material rod; A pressure relief valve (5510) is arranged on the connecting pipe (552), a heat absorbing rod (551) is fixedly installed in the inside of the lower mold (3) cavity close to the connecting pipe (552), a heat conducting ring (553) for thermal compensation of the wave-shaped limiting ring (557) is fixedly installed in the inside of the ring-shaped groove (554), and the heat absorbing rod (551) is fixedly connected with the heat conducting ring (553), and a pressurizing head (558) for reducing friction damage is fixedly installed at one end of the thermal expansion element (559) close to the wave-shaped limiting ring (557). A sliding assembly (56) is arranged in the sleeve (54), the sliding assembly (56) comprises a supporting ring (561) installed in the sleeve (54), a drive shaft sleeve (562) is fixedly installed on the surface of the supporting ring (561) close to the positioning guide column (51), and a rolling ball (563) is rotatably installed in the inside of the drive shaft sleeve (562).

2. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: The top end of the bottom plate (4) is provided with the lower mold (3), the bottom end of the top plate (1) is provided with the upper mold (2), the upper mold (2) and the lower mold (3) slidingly penetrate the positioning guide column (51) and the positioning guide sleeve (53) respectively, and the surfaces of the lower mold (3) and the upper mold (2) close to the positioning guide column (51) are fixedly installed with sealing washers (52).

3. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: A moving plate (566) is slidingly installed in the inside of the supporting ring (561), a first spring (567) is fixedly installed between the moving plate (566) and the inner wall of the supporting ring (561), an oil absorbing cotton (564) for absorbing lubricating oil is fixedly installed on the surface of the moving plate (566) close to the rolling ball (563), and an oil outlet channel is formed between the moving plate (566) and the rolling ball (563).

4. The self-guided positioning mechanism of a precision injection mold according to claim 3, wherein: The rotating rod (565) is rotatably installed in the oil outlet channel, and the rotating rod (565) pushes the moving plate (566) through the rolling ball (563) to press the oil absorption cotton (564) to discharge oil.

5. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: A plurality of pressure stabilizing components (59) are arranged in the positioning guide sleeve (53), the pressure stabilizing component (59) comprises a long groove (594) formed in the inner bottom wall of the positioning guide sleeve (53), the long groove (594) is internally provided with a piston (593), the long groove (594) is fixedly installed with a sliding rod (592) internally, the sliding rod (592) slides through the piston (593), the piston (593) and the inner wall of the long groove (594) are fixedly installed with a second spring (595), and the long groove (594) is externally provided with a gas groove (591) for negative pressure exhaust.

6. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: An exhaust mechanism (6) is arranged between the upper die (2) and the lower die (3), the exhaust mechanism (6) comprises a gas pump (64) fixedly installed on one side of the lower die (3), the top end of the upper die (2) is fixedly installed with an annular pipeline (61), one end of the annular pipeline (61) close to the inner part of the concave die is communicatedly installed with a stepped variable-diameter exhaust pipe (62), and the annular pipeline (61) is communicated with the input end of the gas pump (64) through a suction pipe (63).

7. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: The wave-shaped limiting ring (557) is made of a shape memory alloy material, and the initial wave peak height is the same as the pushing displacement after the thermal expansion component (559) is fully stretched.

8. The self-guided positioning mechanism of a precision injection mold according to claim 1, wherein: The inner bottom wall of the positioning guide sleeve (53) is fixedly installed with a damping spring (58), and the positioning guide column (51) is fixedly installed with a rubber plate (57) at one end close to the damping spring (58).

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