A structure and method for preventing breakage of a deep hole insert pin

Abstract

This invention relates to an active pin retraction structure and method for preventing breakage of deep-hole inserts. It includes a front mold core and a rear mold core. A concave groove is provided on one side surface of the rear mold core, and a first positioning plate and a second positioning plate are disposed within the concave groove. The second positioning plate is located below the first positioning plate, and one or more deep-hole inserts are fixedly disposed on the second positioning plate. A first guide hole is provided on the first positioning plate, and a second guide hole is provided at the bottom of the concave groove, communicating with the product molding cavity of the rear mold core. The first and second positioning plates are connected by an elastic element. When the elastic element is not deformed, the difference between the height of the combination of the first and second positioning plates and the depth of the concave groove is greater than the depth to which the deep-hole insert is inserted into the product. By applying the method of this application, without affecting normal product processing, it is possible to effectively prevent breakage or bending of deep-hole inserts during the retraction process, reducing insert wear.

Description

Technical Field

[0001] This invention relates to the field of injection mold technology, and more specifically, to an active needle retraction structure and method for preventing needle breakage in deep-hole inserts. Background Technology

[0002] Injection molds are used for injection molding plastic products and are a common type of mold. In actual production, for plastic products with deep holes, deep hole inserts are usually required to help form the deep holes. Existing deep hole inserts are designed to be directly set on the rear mold core plate. During the ejection process, the section of the insert inserted into the plastic product only separates from the product after the ejector pin has pushed the product out for a certain distance. During this process, the product is prone to uneven ejection, which can lead to broken or bent inserts. Improvements are needed to avoid this situation. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an active needle retraction structure to prevent needle breakage in deep hole needles, and to provide an active needle retraction method to prevent needle breakage in deep hole needles, in view of the above-mentioned defects of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] An active pin retraction structure is constructed to prevent breakage of deep-hole insert pins. It includes a front mold core and a rear mold core arranged sequentially. Each of the front and rear mold cores has a product forming cavity on one opposite surface. The rear mold core has a concave groove on its surface opposite to the front mold core. A first positioning plate and a second positioning plate, arranged parallel to each other, are disposed within the concave groove. The dimensions of the first and second positioning plates are matched to the dimensions of the concave groove. The second positioning plate is located below the first positioning plate, and one or more deep-hole insert pins are fixedly disposed on the second positioning plate. The first positioning plate has a first guide hole for the deep-hole insert pins to pass through. The bottom of the concave groove has a second guide hole for the deep-hole insert pins to pass through, and the second guide hole communicates with the product forming cavity of the rear mold core. The first and second positioning plates are connected by an elastic element. When the elastic element is not deformed, the difference between the height of the combination of the first and second positioning plates and the depth of the concave groove is greater than the depth to which the deep-hole insert pin is inserted into the product.

[0006] The active needle retraction structure for preventing easy breakage of needles in deep holes, as described in this invention, wherein both ends of the lower surface of the first positioning plate are provided with longitudinal telescopic guide rods and receiving holes for accommodating the telescopic guide rods, and the lower end of the telescopic guide rods is connected to the upper surface of the second positioning plate.

[0007] The active needle retraction structure for preventing easy breakage of needles in deep holes, as described in this invention, includes two springs correspondingly sleeved outside the telescopic guide rod. One end of each spring is fixedly disposed inside the receiving hole, and the other end is connected to the upper surface of the second positioning plate.

[0008] The active needle retraction structure for preventing easy breakage of needles in deep holes, as described in this invention, wherein a distance sensor is provided at the bottom of the receiving hole, and the distance sensor is located inside the telescopic guide rod for detecting the distance of the second positioning plate.

[0009] The active needle retraction structure for preventing easy breakage of deep hole inserts according to the present invention further includes a control host. The control host receives the readings of the two ranging sensors, plots the data change curves of time and readings, and determines the tilt of the second positioning plate based on the degree of agreement between the two data change curves.

[0010] The active needle retraction structure for preventing easy breakage of needles in deep holes as described in this invention includes a telescopic guide rod comprising multiple square tubes sequentially nested together. In two adjacent square tubes, the four outer surfaces of the inner square tube are provided with multiple longitudinally arranged ball bearings, and the four inner walls of the outer square tube are provided with positioning grooves that mate with the ball bearings. The positioning grooves are not connected to either end of the square tube.

[0011] An active needle retraction method for preventing needle breakage in deep-hole needle insertion utilizes the active needle retraction structure described above, and its implementation method is as follows:

[0012] When the mold is closed, the second positioning plate is squeezed into the concave groove, the elastic element is compressed, and the deep hole insert passes through the first guide hole and the second guide hole and partially enters the product forming cavity;

[0013] After the injection-molded product has cooled down, the mold is opened. Before ejecting the product, the pressure on the second positioning plate is released first. The elastic element recovers its deformation and pushes the second positioning plate downward into the concave groove. At the same time, the first positioning plate is pressed against the concave groove for positioning. The deep hole insert is pulled out from the product as the second positioning plate moves downward. During the pulling process, it is guided by the first guide hole and the second guide hole.

[0014] After the deep hole insert is completely removed from the product, proceed with the subsequent product ejection operation.

[0015] The active needle retraction method for preventing easy breakage of deep-hole insert needles according to the present invention further includes:

[0016] Longitudinal telescopic guide rods are provided at both ends of the lower surface of the first positioning plate, and a distance measuring sensor for detecting the distance to the second positioning plate is provided inside the telescopic guide rods;

[0017] Based on the readings of the two ranging sensors, plot the data change curves of time and readings, and determine the tilt of the second positioning plate based on the degree of agreement between the two data change curves.

[0018] The beneficial effects of this invention are as follows: When the mold is closed, the second positioning plate is squeezed into the concave groove, the elastic element is compressed, and the deep hole insert passes through the first guide hole and the second guide hole and partially enters the product molding cavity; after the injection-molded product is cooled, the mold is opened, and the pressure on the second positioning plate is released first before ejecting the product. The elastic element recovers its deformation and squeezes the second positioning plate downward into the concave groove, while the first positioning plate is pressed against the concave groove for positioning. The deep hole insert is pulled out of the product as the second positioning plate moves downward, guided by the first guide hole and the second guide hole during the extraction process; after the deep hole insert is completely pulled out of the product, the subsequent product ejection operation is performed; by applying the method of this application, without affecting normal product processing, it is possible to effectively prevent the deep hole insert from breaking or bending during the extraction process, reduce insert wear, and save costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0020] Figure 1 This is a cross-sectional view of the active needle retraction structure for preventing easy breakage of needles in deep-hole inserts according to a preferred embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the telescopic guide rod of the active needle retraction structure for preventing easy needle breakage in deep hole needles according to a preferred embodiment of the present invention;

[0022] Figure 3 This is a flowchart of an active needle retraction method for preventing easy breakage of needles in deep-hole inserts, according to a preferred embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, a clear and complete description will be provided below in conjunction with the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0024] The preferred embodiment of the present invention provides an active needle retraction structure to prevent easy breakage of needles in deep-hole inserts, such as... Figure 1As shown, see also Figure 2 The device includes a front mold core 1 and a rear mold core 2 arranged sequentially. Each of the front mold core 1 and the rear mold core 2 has a product forming cavity 3 on one opposite side surface. The rear mold core 2 has a concave groove 20 on the side surface opposite to the front mold core 1. A first positioning plate 4 and a second positioning plate 5, arranged parallel to each other, are disposed within the concave groove 20. The dimensions of both the first positioning plate 4 and the second positioning plate 5 are matched to those of the concave groove 20. The second positioning plate 5 is located below the first positioning plate 4, and one or more deep-hole inserts 6 are fixedly disposed on the second positioning plate 5. The first positioning plate 4... A first guide hole 40 is provided for the deep hole insert 6 to pass through, and a second guide hole 21 is provided at the bottom of the concave groove 20 for the deep hole insert 6 to pass through. The second guide hole 21 is connected to the product forming cavity of the rear mold core 2. The first positioning plate 4 and the second positioning plate 5 are connected by an elastic element. When the elastic element is not deformed, the difference between the height of the combination of the first positioning plate 4, the second positioning plate 5 and the elastic element and the depth of the concave groove 20 is greater than the depth of the deep hole insert 6 inserted into the product, so as to ensure that the deep hole insert 6 can be completely withdrawn from the product.

[0025] When the mold is closed, the second positioning plate 5 is squeezed into the concave groove 20, the elastic element is compressed, and the deep hole insert 6 passes through the first guide hole 40 and the second guide hole 21 and partially enters the product molding cavity.

[0026] After the injection-molded product has cooled down, the mold is opened. Before ejecting the product, the pressure on the second positioning plate 5 is released first. The elastic element restores its deformation and pushes the second positioning plate 5 downward into the concave groove 20. At the same time, the first positioning plate 4 is pressed against the concave groove 20 for positioning. The deep hole insert 6 is pulled out from the product as the second positioning plate 5 moves downward. During the pulling process, it is guided by the first guide hole and the second guide hole.

[0027] After the deep hole insert 6 is completely pulled out of the product, proceed with the subsequent product ejection operation.

[0028] By applying the methods of this application, without affecting normal product processing, it is possible to effectively prevent broken or bent needles during the removal process of deep hole inserts, reduce insert wear, and save costs.

[0029] Preferably, both ends of the lower surface of the first positioning plate 4 are provided with longitudinal telescopic guide rods 7 and receiving holes 41 for accommodating the telescopic guide rods. The lower end of the telescopic guide rod 7 is connected to the upper surface of the second positioning plate 5. The elastic element includes two springs 8 correspondingly sleeved outside the telescopic guide rod 7. One end of the spring 8 is fixedly installed in the receiving hole 41, and the other end is connected to the upper surface of the second positioning plate 5.

[0030] The first reason for adopting this special guiding method is that the stroke between the first positioning plate 4 and the second positioning plate 5 is relatively large when they are closing and opening. However, due to the size limitation of the rear mold core 2, the concave groove 20 cannot be designed to be too deep. The second reason is to consider the installation space issue. In the processing of some products, many deep hole inserts are required, and the guiding structure cannot occupy too much space.

[0031] Preferably, the telescopic guide rod 7 includes multiple square tubes 70 arranged in sequence; in two adjacent square tubes 70, the four outer surfaces of the inner square tube 70 are provided with multiple longitudinally arranged ball bearings 71, and the four inner walls of the outer square tube 70 are provided with positioning grooves 72 that cooperate with the ball bearings; the positioning grooves are not connected to the two ends of the square tubes; this ensures better guiding and positioning performance, while having low sliding resistance; of course, it is understood that this is not the only structure, and other existing structural forms can also be used.

[0032] Preferably, a distance sensor 42 is provided at the bottom of the receiving hole 41. The distance sensor 42 is located inside the telescopic guide rod and is used to detect the distance of the second positioning plate 5. It also includes a control host, which receives the readings of the two distance sensors 42, plots the data change curves of time and readings, and judges the tilt of the second positioning plate 5 based on the degree of agreement between the two data change curves.

[0033] This method allows for better monitoring of the tilting state of the second positioning plate, especially during the stages when the second positioning plate is disengaging from the concave groove and when it is entering the concave groove. It ensures that if the second positioning plate tilts during mold closing or opening, the mold opening or closing can be promptly detected and stopped.

[0034] An active needle retraction method for preventing breakage of needles in deep-hole inserts utilizes the active needle retraction structure described above. Figure 3 As shown, its implementation method is as follows:

[0035] S01: When the mold is closed, the second positioning plate is squeezed into the concave groove, the elastic element is compressed, and the deep hole insert passes through the first guide hole and the second guide hole and partially enters the product forming cavity.

[0036] S02: After the injection-molded product has cooled down, the mold opens. Before ejecting the product, the pressure on the second positioning plate is released first. The elastic element recovers its deformation and pushes the second positioning plate downward into the concave groove. At the same time, the first positioning plate is pressed against the concave groove for positioning. The deep hole insert is pulled out from the product as the second positioning plate moves downward. During the pulling process, it is guided by the first guide hole and the second guide hole.

[0037] S03: After the deep hole insert pin is completely removed from the product, proceed with the subsequent product ejection operation.

[0038] By applying the methods of this application, without affecting normal product processing, it is possible to effectively prevent broken or bent needles during the removal process of deep hole inserts, reduce insert wear, and save costs.

[0039] Preferably, the method further includes:

[0040] Longitudinal telescopic guide rods are provided at both ends of the lower surface of the first positioning plate, and a distance measuring sensor for detecting the distance to the second positioning plate is provided inside the telescopic guide rods;

[0041] Based on the readings of the two ranging sensors, plot the data change curves of time and readings, and determine the tilt of the second positioning plate based on the degree of agreement between the two data change curves.

[0042] This method allows for better monitoring of the tilting state of the second positioning plate, especially during the stages when the second positioning plate is disengaging from the concave groove and when it is entering the concave groove. It ensures that if the second positioning plate tilts during mold closing or opening, the mold opening or closing can be promptly detected and stopped.

[0043] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. An active needle retraction structure to prevent easy breakage of needles in deep-hole inserts, characterized in that, The device includes a front mold core and a rear mold core arranged sequentially. Each of the front and rear mold cores has a product forming cavity on one opposite surface. The rear mold core has a concave groove on its surface opposite the front mold core. A first positioning plate and a second positioning plate, arranged parallel to each other, are disposed within the concave groove. The dimensions of the first and second positioning plates are matched to the dimensions of the concave groove. The second positioning plate is located below the first positioning plate, and one or more deep-hole inserts are fixedly disposed on the second positioning plate. The first positioning plate has a first guide hole for the deep-hole inserts to pass through, and the bottom of the concave groove has a second guide hole for the deep-hole inserts to pass through, communicating with the product forming cavity of the rear mold core. The first and second positioning plates are connected by an elastic element. When the elastic element is not deformed, the difference between the height of the combination of the first and second positioning plates and the depth of the concave groove is greater than the depth to which the deep-hole inserts are inserted into the product. The lower surface of the first positioning plate... Both ends are provided with longitudinal telescopic guide rods and receiving holes for accommodating the telescopic guide rods. The lower end of the telescopic guide rod is connected to the upper surface of the second positioning plate. The elastic element includes two springs correspondingly sleeved on the telescopic guide rods. One end of each spring is fixedly disposed in the receiving hole, and the other end is connected to the upper surface of the second positioning plate. A distance sensor is disposed at the bottom of the receiving hole. The distance sensor is located inside the telescopic guide rod and is used to detect the distance to the second positioning plate. The structure also includes a control host. The control host receives the readings of the two distance sensors, plots the data change curves of time and readings, and judges the tilt of the second positioning plate based on the degree of agreement between the two data change curves. The telescopic guide rod includes multiple square tubes sleeved in sequence. In two adjacent square tubes, the four outer surfaces of the inner square tube are provided with multiple longitudinally arranged ball bearings, and the four inner walls of the outer square tube are provided with positioning grooves that cooperate with the ball bearings. The positioning grooves are not connected to the two ends of the square tubes.

2. An active needle retraction method for preventing easy breakage of needles in deep-hole settings, employing the active needle retraction structure for preventing easy breakage of needles in deep-hole settings as described in claim 1, characterized in that, The implementation method is as follows: When the mold is closed, the second positioning plate is squeezed into the concave groove, the elastic element is compressed, and the deep hole insert passes through the first guide hole and the second guide hole and partially enters the product forming cavity; After the injection-molded product has cooled down, the mold is opened. Before ejecting the product, the pressure on the second positioning plate is released first. The elastic element recovers its deformation and pushes the second positioning plate downward into the concave groove. At the same time, the first positioning plate is pressed against the concave groove for positioning. The deep hole insert is pulled out from the product as the second positioning plate moves downward. During the pulling process, it is guided by the first guide hole and the second guide hole. After the deep hole insert is completely removed from the product, proceed with the subsequent product ejection operation. The method further includes: Based on the readings of the two ranging sensors, plot the data change curves of time and readings, and determine the tilt of the second positioning plate based on the degree of agreement between the two data change curves.

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