Positioning device for embedded nut of injection molding part

Abstract

The utility model relates to the technical field of injection molding, and discloses an injection molding part embedded nut positioning device which comprises an injection mold and a positioning rod, a nut embedded hole is formed in the injection mold, external threads are arranged at the lower end of the positioning rod, the lower end of the positioning rod is connected with a nut in a matched mode, and the interior of the positioning rod is of a hollow structure. An air pipe is arranged at the top of the positioning rod, the positioning rod is sleeved with a limiting sleeve, a gap exists between the inner wall of the limiting sleeve and the positioning rod, the side wall of the limiting sleeve extends outwards to form a limiting plate of an annular structure, and a through hole is formed in the position, above the outer thread, of the side wall of the positioning rod. The sealing structure effectively prevents molten plastic from permeating into the internal thread of the nut, solves the problems of thread blockage and adhesive tape failure in the traditional process, and has the advantages of high positioning precision, reliable sealing and high applicability.

Description

TECHNICAL FIELD

[0001] The utility model relates to injection molding technical field especially a kind of injection molding part embedded nut positioning device. BACKGROUND

[0002] In injection molding process, the positioning technology of embedded nut is widely used in the field of internal thread insert fixing of plastic products. In traditional process, mechanical clamp fixing, magnetic adsorption positioning or pasting sealing tape on the end of nut are usually used for embedded positioning. However, in actual production process, it is found that when molten plastic is injected into mold cavity at high pressure, due to the assembly gap between the inner hole of nut and the positioning device, combined with the high flowability characteristics of plastic melt, part of molten plastic is easily penetrated into the internal thread area of nut. This overflow phenomenon not only causes burr to be formed in the gap between thread tooth type, but also may cause defects such as reduction of effective engagement height of internal thread and deformation of thread lead, and even cause bolt to be unable to be normally screwed in during subsequent assembly process. Although sealing tape used in prior art can temporarily block, it is easy to soften and fail in high temperature injection environment, and subsequent tape stripping process needs to be added, which significantly reduces production efficiency. Therefore, it is urgent to develop an embedded nut positioning device which can effectively seal the internal thread channel of nut and has good positioning stability and process adaptability. SUMMARY

[0003] The utility model discloses a kind of embedded nut positioning devices of injection molding part, by mechanical limit and pressure sealing are combined, avoid molten plastic penetration into the internal thread of nut and cause thread failure etc., improve the reliability of embedded nut.

[0004] The utility model discloses a kind of embedded nut positioning devices of injection molding part, including injection mold, nut embedding hole is set on injection mold, still including a positioning rod, the lower end of positioning rod is set outer thread, the lower end of positioning rod is connected with nut cooperation, the inside of positioning rod is hollow structure, gas pipe is set on the top of positioning rod, pressure regulating valve is set on gas pipe, positioning sleeve is connected with the outside of positioning rod, there is gap between the inner wall of positioning sleeve and positioning rod, the top between positioning sleeve and positioning rod is sealed connection, the side wall of positioning sleeve extends outward and forms the limiting plate of annular structure, the spacing between limiting plate and the lower end of positioning sleeve is equal to the thickness of the side wall of injection mold corresponding place of nut embedding hole, the lower end outer diameter of positioning sleeve is equal to the inner diameter of nut embedding hole, through hole is set on the side wall of positioning rod above outer thread, pressure gauge is set on the side wall of positioning sleeve, the pressure gauge is used to measure the pressure in the gap between positioning sleeve and positioning rod.

[0005] Positioning rod inner wall in the range corresponding to nut is also provided with a plurality of through holes, and the through holes penetrate the side wall of the positioning rod at the outer thread.

[0006] The inner wall of the lower end of the limiting sleeve is provided with an inward annular protrusion, which is fixedly connected with the outer wall of the positioning rod, and a plurality of air holes are arranged on the annular protrusion and penetrate the annular protrusion along the axial direction of the positioning rod.

[0007] The lower surface of the limiting plate is provided with an inner groove, and a sealing strip is arranged in the inner groove, and the inner diameter of the sealing strip is greater than the diameter of the nut pre-buried hole on the injection mold.

[0008] The injection part pre-buried nut positioning device obtained by the utility model has the following beneficial effects:

[0009] 1. The hollow positioning rod is connected with the air pipe, high-pressure air is transported inward by the air pressure regulating valve, a positive pressure environment is continuously maintained during the injection process, and the molten plastic is effectively prevented from penetrating into the nut internal thread;

[0010] 2. The gap between the limiting sleeve and the positioning rod is designed in combination with the pressure gauge monitoring, so that the dynamic balance control of the injection pressure and the sealed air pressure is realized;

[0011] 3. The composite structure of mechanical limiting and air pressure sealing simplifies the device and realizes reliable positioning at the same time;

[0012] 4. The limiting sleeve is designed to adapt to different specifications of nut pre-buried holes, and the cost of the positioning device is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The structure of the utility model is shown in the figure. DETAILED DESCRIPTION

[0014] In order to further illustrate the technical means and effects adopted by the utility model to achieve the predetermined utility model purposes, the specific embodiments, structures, features and effects according to the utility model will be described in detail as follows in combination with the drawings and the preferred embodiments.

[0015] Embodiment 1:

[0016] As Figure 1The utility model discloses a kind of positioning devices of injection-molded part pre-buried nut, including injection mold 1, nut pre-buried hole is provided on injection mold 1, further including a locating rod 2, the lower end of the locating rod 2 is provided with external thread, the lower end of locating rod 2 is connected with nut 7, the inside of the locating rod 2 is hollow structure, air pipe 5 is provided on the top of locating rod 2, air pressure regulating valve 6 is provided on air pipe 5, locating sleeve 3 is sleeved on the outside of locating rod 2, there is gap between the inner wall of locating sleeve 3 and locating rod 2, locating sleeve 3 is sealedly connected between the top and locating rod 2, the side wall of locating sleeve 3 extends outward to form annular structure's limiting plate 4, the interval between limiting plate 4 and the lower end of locating sleeve 3 is equal to the thickness of the side wall of injection mold 1 corresponding place of nut pre-buried hole, the lower end outer diameter of locating sleeve 3 is equal to the inner diameter of nut pre-buried hole, through hole 8 is provided on the side wall of locating rod 2 above external thread, pressure gauge 11 is provided on the side wall of locating sleeve 3, and the pressure gauge 11 is used to measure the air pressure in the gap between locating sleeve 3 and locating rod 2.

[0017] In the scheme of the application, the injection mold 1 is a mold used in the existing injection molding process of injection-molded parts, and its shape is determined according to the injection-molded part and is not limited. Of course, according to actual needs, nut pre-buried holes are opened on the surface of the injection mold 1 corresponding to the positions where the nut 7 needs to be pre-buried on the surface of the injection-molded part, the nut 7 is positioned through the pre-buried holes, and the nut 7 is embedded into the injection-molded part.

[0018] The locating rod 2 is used, and the locating sleeve 3 is fixed outside the locating rod 2, and the lower end of the locating sleeve 3 is provided with the limiting plate 4 extending outward, the limiting plate 4 is used to abut against the outside of the nut pre-buried hole of the injection mold 1, the nut 7 to be pre-buried is connected to the lower end of the locating rod 2 through threads, and the upper end of the nut 7 contacts the lower end of the locating sleeve 3. At this time, the lower end of the locating rod 2 is flush with the lower surface of the nut 7, or the lower end of the locating rod 2 is slightly lower than the lower surface of the nut 7. When the nut 7 needs to be pre-buried, the nut 7 assembled on the lower end of the locating rod 2 is inserted into the nut pre-buried hole together with the locating rod 2 and the locating sleeve 3, at this time, the lower end of the locating sleeve 3 is butted with the nut pre-buried hole, and the limiting plate 4 contacts the side wall of the injection mold 1 to limit the axial position of the locating rod 2. Since the nut 7 contacts the lower end face of the locating sleeve 3, and the lower end face of the locating sleeve 3 is flush with the inner surface of the injection mold 1 according to the design, the nut 7 can be pre-buried in the injection-molded part, and the surface of the nut 7 is flush with the surface of the injection-molded part.

[0019] In the normal injection molding process, because the molten plastic is injected into the mold by pressure to flow, and maintain a certain pressure. So in the positioning rod 2 by the air pipe 5 into the high pressure gas, the air pipe 5 is connected to the high pressure gas source. The amount of high pressure gas can be controlled by the air pressure regulating valve 6, to control the air pressure inside the positioning rod 2. The positioning rod 2 inside through the hole 8 with the limit sleeve 3 inside the communication, so the gap between the limit sleeve 3 and the positioning rod 2 can also be maintained at the required pressure. Because the nut 7 and the lower end of the positioning rod 2 is connected with the outer thread process, there is a certain gap, and the gap is connected with the gap between the limit sleeve 3 and the positioning rod 2, so the gas flow will enter the gap between the nut 7 and the positioning rod 2, and maintain the set pressure, so that in the injection molding, under the action of the air pressure between the nut 7 and the positioning rod 2, the molten plastic is unable to enter the gap inside, will not affect the internal thread of the nut 7. The pressure gauge 11 is arranged on the limit sleeve 3, which can directly measure and display the air pressure in the gap between the limit sleeve 3 and the positioning rod 2, so as to avoid the air pressure being too large to cause the gas flow into the injection mold 1, affecting the injection effect. Of course, the pressure gauge 11 and the air pressure regulating valve 6 can be linked through the controller, and the air pressure can be kept stable under the cooperation of the controller set pressure value and the pressure gauge 11.

[0020] The positioning rod 2 in the range corresponding to the nut 7 is also provided with a plurality of through holes 8, and the through holes 8 penetrate the side wall of the positioning rod 2 at the outer thread. The positioning rod 2 corresponding to the nut 7 is also provided with a through hole 8, so that the gas flow can directly enter the gap between the nut 7 and the positioning rod 2 through the through hole 8, so as to ensure that the air pressure in the gap between the nut 7 and the positioning rod 2 is kept in a stable state, effectively preventing the molten plastic from entering the gap.

[0021] The inner wall of the lower end of the limit sleeve 3 is provided with an inward annular protrusion 9, which is fixedly connected between the outer wall of the positioning rod 2, and a plurality of air holes 10 are arranged on the annular protrusion 9, which penetrate the annular protrusion 9 along the axial direction of the positioning rod 2.

[0022] The design of the annular protrusion 9 makes the connection between the limit sleeve 3 and the positioning rod 2 more firm and stable, the sealing performance of the top is better, and the positioning of the nut 7 is more accurate. The air holes 10 can keep the upper and lower gaps of the annular protrusion 9 in communication, and the air pressure is stable.

[0023] The lower surface of the limiting plate 4 is provided with an inner groove 12, and a sealing strip 13 is arranged in the inner groove 12, and the inner diameter of the sealing strip 13 is greater than the diameter of the nut embedded hole on the injection mold 1.

[0024] The design of the sealing strip 13 can prevent the internal air pressure from overflowing outward between the limiting plate 4 and the injection mold 1, so as to effectively keep the internal air pressure stable.

[0025] In the description of the application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0026] In the description of the application, it needs to be explained that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection; it can be direct connection, or indirect connection through intermediate medium; it can be the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0027] In this application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "above" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "under", "below" and "below" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0028] The above merely describes preferred embodiments of the present application and is not intended to limit the present application in any form. Although the present application has been disclosed with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make minor changes or modifications to the disclosed technical content to obtain equivalent embodiments with equivalent changes, as long as the changes or modifications do not deviate from the technical solution of the present application. Any simplification, modification, equivalent change or modification of the above embodiments based on the technical essence of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A positioning device for a pre-embedded nut in an injection molded part, comprising an injection mold, wherein a pre-embedded nut hole is provided on the injection mold, characterized in that: The positioning rod is internally hollow, and a gas pipe is arranged at the top of the positioning rod, and a gas pressure adjusting valve is arranged on the gas pipe; a limiting sleeve is sleeved outside the positioning rod, and a gap exists between the inner wall of the limiting sleeve and the positioning rod; the top of the limiting sleeve is in sealed connection with the positioning rod; the side wall of the limiting sleeve extends outward to form a limiting plate in an annular structure; the spacing between the limiting plate and the lower end of the limiting sleeve is equal to the thickness of the side wall of the injection mold at the corresponding position of the embedded hole of the nut; the outer diameter of the lower end of the limiting sleeve is equal to the inner diameter of the embedded hole of the nut; a through hole is arranged on the side wall of the positioning rod above the external thread; and a pressure gauge is arranged on the side wall of the limiting sleeve, and the pressure gauge is used to measure the air pressure in the gap between the limiting sleeve and the positioning rod.

2. A device for positioning a nut in an injection molded part according to claim 1, characterized in that: A plurality of through holes are arranged on the inner wall of the positioning rod in the range corresponding to the nut, and the through holes penetrate the side wall of the positioning rod at the position of the external thread.

3. A device for positioning a nut in an injection moulded part according to claim 1 or 2, c h a r a c t e r i s e d in that: An inward annular protrusion is arranged on the inner wall of the lower end of the limiting sleeve, and the annular protrusion is fixedly connected with the outer wall of the positioning rod; a plurality of air holes are arranged in an array on the annular protrusion, and the air holes penetrate the annular protrusion in the axial direction of the positioning rod.

4. A device for positioning a nut in an injection molded part according to claim 3, characterized in that: An inner groove is arranged on the lower surface of the limiting plate, and a sealing strip is arranged in the inner groove, and the inner diameter of the sealing strip is greater than the diameter of the embedded hole of the nut on the injection mold.

Images