Internal thread injection mold and demoulding method thereof

Abstract

The invention discloses an internal thread injection molded part mold and a demoulding method thereof, which belongs to the technical field of injection molds, and comprises a front mold and a rear mold, wherein the front mold comprises a top plate, a front mold fixing plate and a front mold core, and the rear mold comprises a rear mold fixing plate, a rear mold core and a bottom plate, a sliding rod is arranged between the top plate and the bottom plate, the front mold fixing plate and the rear mold fixing plate are arranged on the sliding rod, the front mold core is arranged in the front mold fixing plate, and the rear mold core is arranged in the rear mold fixing plate; a threaded mold core is arranged on the front mold core, the threaded mold core is composed of two semicircular mold cores, and an insert is arranged in the threaded mold core; the insert is fixed on the top plate; an injection mold cavity is arranged on the rear mold core, and an ejector pin is arranged on the bottom plate; the invention is convenient to operate, highly practical, and has tight mold closing, and the invention effectively solves the problems of the prior art that it is time-consuming and labor-intensive to separate the internal thread from the mold after injection molding, the demoulding efficiency is low, and automatic demoulding cannot be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, in particular to an internal thread injection mold and a demoulding method thereof. Background Art

[0002] Injection molded workpieces are the most common production materials, especially widely used in the production of daily necessities. The raw material and processing costs are relatively low, and they are durable, with large and stable market demand. Injection molded workpieces often need to be processed with internal thread structures to facilitate connection with other parts. However, after injection molding, the internal thread is difficult to separate from the mold, and demolding is time-consuming and labor-intensive, with low demolding efficiency, and automatic demolding cannot be achieved. When there are higher requirements for mold design, demolding must be timely and the mold temperature is high, which can easily cause harm to operators. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides an internal thread injection mold and a demolding method thereof, which solves the problems in the prior art that the internal thread is difficult to separate from the mold after injection molding, demolding is time-consuming and labor-intensive, the demolding efficiency is low, and automatic demolding cannot be achieved.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an internal thread injection mold, comprising a front mold and a rear mold, the front mold comprising a top plate, a front mold fixing plate and a front mold core, the rear mold comprising a rear mold fixing plate, a rear mold core and a bottom plate, a sliding rod is provided between the top plate and the bottom plate, the front mold fixing plate and the rear mold fixing plate are provided on the sliding rod, the front mold core is provided in the front mold fixing plate, and the rear mold core is provided in the rear mold fixing plate; a threaded mold core is provided on the front mold core, the threaded mold core is composed of two semicircular mold cores, and an insert is provided in the threaded mold core; the threaded mold core can be moved together or apart on the front mold core, and an elastic part is provided to enable it to automatically move together; the insert is fixed on the top plate; an injection mold cavity is provided on the rear mold core, and an ejector pin is provided on the bottom plate.

[0005] Furthermore, mounting hole mold rods are provided on both sides of the threaded mold core on the front mold core, and a limit head is provided at the tail end of the mounting hole mold rod. The insert is fixedly connected to the top plate through a connecting plate, and through holes are provided on both sides of the connecting plate. The front end diameter of the through hole is smaller than the limit head diameter of the mounting hole mold rod, and the rear end diameter of the through hole is larger than the limit head diameter of the mounting hole mold rod. The front end of the mounting hole mold rod is arranged through the connecting plate, and the length of the mounting hole mold rod is equal to the sum of the connection lengths of the insert and the connecting plate.

[0006] Furthermore, a front slide bar is provided on the top plate, and a rear slide bar is provided on the bottom plate. The front slide bar and the rear slide bar are staggered, and the front mold fixing plate and the rear mold fixing plate are both provided with sliding holes for the front slide bar and the rear slide bar; when the mold is closed, the front slide bar and the rear slide bar both pass through the front mold fixing plate and the rear mold fixing plate.

[0007] Furthermore, the front mold fixing plate and the rear mold fixing plate are respectively provided with guide rods and guide holes, and the diameter of the guide holes is larger than the diameter of the guide rods.

[0008] Furthermore, through holes corresponding to the connecting plates are provided on both sides of the insert, and the front end of the mounting hole mold rod passes through the insert.

[0009] Furthermore, the front mold core is provided with a feed hole, a cooling hole and a drainage groove, and the drainage groove is connected to the threaded mold core.

[0010] Furthermore, the insert is in a "T"-shaped structure, and the front end of the insert is thinner than the rear end, and the front end is narrower than the rear end.

[0011] Furthermore, the elastic member is a spring with a spiral structure.

[0012] Further, the demoulding method of the internal thread injection molded part mold comprises the following steps:

[0013] Step 1: When the mold is closed, the rear mold moves toward the front mold. During the mold closing process, the mold closing accuracy is improved by means of the guide rods (16) and guide holes (17) respectively provided on the front mold fixing plate (1) and the rear mold fixing plate (4); when the threaded mold core (7) is placed in the injection mold cavity (9), the raw material is injected into the feed hole (18) through the feed hole (18) provided on the front mold core (2), and then the raw material is drained to the threaded mold core (7) through the drainage groove (19), so as to realize the rapid injection of the raw material;

[0014] Step 2: When demoulding, the front mold and the rear mold are separated in opposite directions, and the rear mold drives the front mold to move in the direction of movement of the rear mold. At this time, the insert (8) moves backward in the thread mold core (7), thereby causing the thread mold core (7) to automatically move together. Due to the pulling action of the rear mold, the thread mold core (7) is withdrawn a certain distance before the installation hole mold rod (10), and then the installation hole mold rod (10) is withdrawn, so that the thread mold core (7) can realize automatic core pulling action when withdrawing from the injection mold cavity (9);

[0015] Step 3: After the automatic core pulling action of step 2 is completed, the injection molded part is now bonded to the rear mold, and then the ejector pin provided on the rear mold bottom plate (6) is used to impact the injection molded part on the rear mold, thereby causing the injection molded part to fall off the rear mold core (5), thereby achieving automatic demoulding.

[0016] The present invention provides an internal thread injection mold and a demoulding method thereof, which have the following beneficial effects:

[0017] The present invention ensures that the threaded mold core can move closer or apart on the front mold core through an elastic member arranged on the front mold core by the threaded mold core; the insert block is arranged in the threaded mold core and the front end of the insert block is thinner than the rear end and the front end is narrower than the rear end, so as to ensure the threaded mold core to be separated before mold closing and to automatically move closer to the threaded mold core after demolding; the top plate is fixed in the mold closing and is fixedly connected to the top plate by the insert block, and the insert block can withdraw a part of the threaded mold core during demolding, so as to ensure the threaded mold core to automatically move closer to the threaded mold core and facilitate rapid demolding; through holes corresponding to the connecting plates are arranged on both sides of the insert block, and the front end of the mounting hole mold rod passes through the insert block, so as to stabilize the insert block The function is to prevent the mold from swinging up and down during the mold closing or demoulding process. Through the through holes set on both sides of the connecting plate, the front end diameter of the through hole is smaller than the limit head diameter of the mounting hole mold rod, and the rear end diameter of the through hole is larger than the limit head diameter of the mounting hole mold rod, ensuring that the mounting hole mold rod can move in the through hole of the connecting plate without falling off. The length of the mounting hole mold rod is equal to the sum of the connection lengths of the insert and the connecting plate, so that during the mold closing process, when the insert moves backward, the mounting hole mold rod continues to move forward with the threaded mold core. During demoulding, when the rear mold moves in the opposite direction, the threaded mold core first withdraws a short distance from the injection mold cavity. At this time, the mounting hole mold rod plays a stabilizing role for the injection molded part, thereby Ensure that the threaded mold core is separated from the injection molded part to realize the core pulling process; the sliding rods staggered between the top plate and the bottom plate facilitate the movement of the front mold fixing plate and the rear mold fixing plate during mold closing or demolding; the guide rods and guide holes are respectively arranged on the front mold fixing plate and the rear mold fixing plate, and the guide hole diameter is larger than the guide rod diameter, so as to ensure that the guide rod can be inserted into the guide hole, thereby improving the accuracy of mold closing and thus improving the qualified rate of the product; the drainage groove is connected to the threaded mold core, and during the mold closing process, the raw materials are fed in through the feed hole, and then introduced into the threaded mold core through the drainage groove, so as to realize rapid injection during the mold closing process and improve production efficiency; through the cooling hole Cooling liquid is injected to condense the injection molded part during demoulding, so as to facilitate the core pulling of the threaded mold core; a spring with a spiral structure is adopted as the elastic part, so as to increase the service life of the threaded mold core that can move together or apart on the front mold core; the present invention is convenient to operate, highly practical, and has tight mold closing, and the injection molded parts are perfect; the mold closing and demoulding of the above-mentioned mold do not require manual participation, thereby reducing labor costs, and the overall connection structure of the mold of the present invention is not prone to failure; the present invention effectively solves the problems of the prior art that the internal thread is difficult to separate from the mold after injection molding, and demoulding is time-consuming and labor-intensive, the demoulding efficiency is low, and automatic demoulding cannot be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the mold closing of the internal thread injection molded part of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the internal thread injection molded part mold before the front mold is closed.

[0020] Figure 3It is a schematic diagram of the structure of the internal thread injection mold after the front mold is closed.

[0021] Figure 4 It is a structural schematic diagram of the front mold core of the internal thread injection molded part mold of the present invention.

[0022] Figure 5 It is a structural schematic diagram of the rear mold core of the internal thread injection molded part mold of the present invention.

[0023] Figure 6 It is a schematic structural diagram of the mold insert of the internal thread injection molded part of the present invention.

[0024] Figure 7 The figure is a top view structural schematic diagram of the thread core of the internal thread injection mold of the present invention.

[0025] Figure 8 It is a schematic structural diagram of the elastic part of the mold for the internal thread injection molded part of the present invention.

[0026] In the figure, 1-front fixed plate, 2-front mold core, 3-top plate, 4-rear mold fixed plate, 5-rear mold core, 6-bottom plate, 7-threaded mold core, 8-insert block, 9-injection mold cavity, 10-mounting hole mold rod, 11-limiting head, 12-connecting plate, 13-front slide rod, 14-rear slide rod, 15-slide hole, 16-guide rod, 17-guide hole, 18-feeding hole, 19-drainage groove, 20-elastic part, 21-cooling hole. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with embodiments and drawings, but the present invention is not limited to the following embodiments. It can be foreseen that various changes may occur in the implementation of the present invention in combination with the prior art by those skilled in the art.

[0028] like Figure 1-8The present invention provides an internal thread injection mold, comprising a front mold and a rear mold, wherein the front mold comprises a top plate 3, a front mold fixing plate 1 and a front mold core 2, and the rear mold comprises a rear mold fixing plate 4, a rear mold core 5 and a bottom plate 6, a sliding rod is provided between the top plate 3 and the bottom plate 6, the front mold fixing plate 1 and the rear mold fixing plate 4 are provided on the sliding rod, so as to facilitate the movement of the front mold fixing plate 1 and the rear mold fixing plate 4 during mold closing or demolding, the front mold core 2 is provided in the front mold fixing plate 1, and the rear mold core 5 is provided in the rear mold fixing plate 4, and the front mold fixing plate 1 and the rear mold fixing plate 4 are respectively provided with a guide rod 16 and a guide hole 17, and the diameter of the guide hole 17 is larger than the diameter of the guide rod 16, so as to ensure Ensure that the guide rod 16 can be inserted into the guide hole 17 during the mold closing process to improve the accuracy of the mold closing; the front mold core 2 is provided with a feed hole 18, a cooling hole 21 and a drainage groove 19, the drainage groove 19 is connected to the threaded mold core, and the drainage groove 19 is also connected to the accessory mold module. When the mold is closed, the raw material is injected into the feed hole 18 through the feed hole 18 set on the front mold core 2, and then the raw material is drained to the threaded mold core 7 and the accessory mold module through the drainage groove 19, so as to realize the rapid injection of raw materials and improve work efficiency; when demolding, the coolant is injected into the cooling hole 21 through the cooling hole 21 set on the front mold core 2, so as to cool the front mold core 2 on the front mold fixing plate 1, so as to facilitate the subsequent demolding.

[0029] The front mold core 2 of the present invention is provided with a thread mold core 7, which is composed of two semicircular mold cores. The thread mold core 7 can be moved together or apart on the front mold core 2, and is provided with an elastic member 20 to enable it to automatically move together. The elastic member 20 adopts a spring with a wire diameter of 50-200mm and has a spiral structure, which improves the service life of the thread mold core 7 that can move together or apart on the front mold core 2; an insert block 8 is provided in the thread mold core 7, and the insert block 8 has a "T"-shaped structure The front end of the insert block 8 is thinner than the rear end, and the front end is narrower than the rear end, so as to ensure that the threaded mold core 7 can move closer or apart during the mold closing and demolding process; the insert block 8 is fixed on the top plate 3, and the top plate 3 is provided with a front slide bar 13, and the bottom plate 6 is provided with a rear slide bar 14, and the front slide bar 13 and the rear slide bar 14 are staggered, and the front mold fixing plate 1 and the rear mold fixing plate 4 are both provided with slide holes 15 of the front slide bar 13 and the rear slide bar 14; when the mold is closed, the front slide bar 13 and the rear slide bar 14 pass through the front slide bar 13 and the rear slide bar 14 The mold fixing plate 1 and the rear mold fixing plate 4; the threaded mold core 7 on the front mold core 2 is provided with a mounting hole mold rod 10 on both sides, and the mounting hole mold rod 10 is provided with a limit head 11 at the tail end, and the insert 8 is fixedly connected to the top plate 3 through a connecting plate 12, and through holes are provided on both sides of the connecting plate 12, and the front end diameter of the through hole is smaller than the limit head 11 diameter of the mounting hole mold rod 10, and the rear end diameter of the through hole is larger than the limit head 11 diameter of the mounting hole mold rod 10, so as to ensure that the mounting hole mold rod 10 is in the through hole of the connecting plate 12 It can move freely without sliding out, and the front end of the mounting hole mold rod 10 is set through the connecting plate 12, and the length of the mounting hole mold rod 10 is equal to the sum of the connection lengths of the insert 8 and the connecting plate 12; through holes corresponding to the connecting plate 12 are provided on both sides of the insert 8, and the front end of the mounting hole mold rod 10 is set through the insert 8; the rear mold core 5 is provided with an injection mold cavity 9, and the bottom plate 6 is provided with an ejector pin, which exerts a knocking force on the injection molded part stuck on the rear mold to make it fall off, thereby realizing the automatic falling off process.

[0030] The present invention provides a demoulding method for an internal thread injection molded part, comprising the following steps:

[0031] Step 1: When the mold is closed, the rear mold moves toward the front mold. During the mold closing process, the mold closing accuracy is improved by means of the guide rods (16) and guide holes (17) respectively provided on the front mold fixing plate (1) and the rear mold fixing plate (4); when the threaded mold core (7) is placed in the injection mold cavity (9), the raw material is injected into the feed hole (18) through the feed hole (18) provided on the front mold core (2), and then the raw material is drained to the threaded mold core (7) through the drainage groove (19), so as to realize the rapid injection of the raw material;

[0032] Step 2: When demoulding, the front mold and the rear mold are separated in opposite directions, and the rear mold drives the front mold to move in the direction of movement of the rear mold. At this time, the insert (8) moves backward in the thread mold core (7), thereby causing the thread mold core (7) to automatically move together. Due to the pulling action of the rear mold, the thread mold core (7) is withdrawn a certain distance before the installation hole mold rod (10), and then the installation hole mold rod (10) is withdrawn, so that the thread mold core (7) can realize automatic core pulling action when withdrawing from the injection mold cavity (9);

[0033] Step 3: After the automatic core pulling action of step 2 is completed, the injection molded part is now bonded to the rear mold, and then the ejector pin provided on the rear mold bottom plate (6) is used to impact the injection molded part on the rear mold, thereby causing the injection molded part to fall off the rear mold core (5), thereby achieving automatic demoulding.

[0034] In the present invention, when the mold is closed, the top plate 3 on the front mold is fixed, the front mold fixing plate 1 moves toward the rear mold, and the rear mold moves toward the front mold, and the moving speed of the rear mold is greater than the moving speed of the front mold; then, by respectively providing a guide rod 16 and a guide hole 17 on the front mold fixing plate 1 and the rear mold fixing plate 4, wherein the diameter of the guide hole 17 is greater than the diameter of the guide rod 16, it is ensured that the guide rod 16 can be inserted into the guide hole 17 during the mold closing process, thereby improving the accuracy of the mold closing; when the front mold and the rear mold are closed, the raw material is injected into the feed hole 18 through the feed hole 18 provided on the front mold core 2, and then the raw material is drained to the threaded mold core 7 and the accessory mold module through the drainage groove 19, thereby realizing rapid injection of the raw material and improving the work efficiency; When the mold is fully closed, the threaded mold core 7 is placed in the injection mold cavity 9 for injection molding, and then the coolant is injected into the cooling hole 21 provided on the front mold core 2 to cool the front mold core 2 on the front mold fixing plate 1, thereby condensing the injection molded part to ensure the separation of the injection molded part from the threaded mold core 7; and because the front end of the insert 8 is thinner than the rear end and the front end is narrower than the rear end, it is arranged in the threaded mold core 7; the insert 8 is fixed on the top plate 3, and during the demolding process, when the rear mold moves in the opposite direction, the front mold fixing plate 1 is driven to move toward the rear mold. At this time, the insert 8 moves backward in the threaded mold core 7, thereby prompting the threaded mold core 7 to automatically approach, and the mounting hole mold rod 10 continues to move toward the rear mold direction with the threaded mold core 7.

[0035] During demoulding, the front mold and the rear mold separate in opposite directions, and the rear mold drives the front mold to move in the direction of movement of the rear mold. At this time, the insert 8 moves backward in the threaded mold core 7, thereby prompting the threaded mold core 7 to automatically approach. Due to the pulling action of the rear mold, the threaded mold core 7 withdraws a distance earlier than the mounting hole mold rod 10, and then the mounting hole mold rod 10 withdraws. The mounting hole mold rod 10 here stabilizes the injection molded part, thereby ensuring that the threaded mold core 7 can automatically pull out the core when withdrawing from the injection mold cavity 9; at this time, the injection molded part is bonded to the rear mold, and then the ejector provided on the rear mold bottom plate 6 hits the injection molded part on the rear mold, thereby causing the injection molded part to fall off the rear mold core 5, and automatic demoulding is achieved.

[0036] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0037] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A mold for an internally threaded injection molded part, comprising a front mold and a rear mold, wherein the front mold comprises a top plate (3), a front mold fixing plate (1) and a front mold core (2), and the rear mold comprises a rear mold fixing plate (4), a rear mold core (5) and a bottom plate (6), wherein: A slide bar is provided between the top plate (3) and the bottom plate (6); the front mold fixing plate (1) and the rear mold fixing plate (4) are provided on the slide bar; the front mold core (2) is provided in the front mold fixing plate (1); and the rear mold core (5) is provided in the rear mold fixing plate (4); a threaded mold core (7) is provided on the front mold core (2); the threaded mold core (7) is composed of two semicircular mold cores; an insert (8) is provided in the threaded mold core (7); the threaded mold core (7) can be moved together or apart on the front mold core (2), and an elastic member (20) is provided to enable it to automatically move together; the insert (8) is fixed on the top plate (3); an injection mold cavity (9) is provided on the rear mold core (5), and an ejector pin is provided on the bottom plate (6); The threaded mold core (7) on the front mold core (2) is provided with mounting hole mold rods (10) on both sides, and a limit head (11) is provided at the rear end of the mounting hole mold rod (10); the insert (8) is fixedly connected to the top plate (3) through a connecting plate (12); through holes are provided on both sides of the connecting plate (12); the front end diameter of the through hole is smaller than the diameter of the limit head (11) of the mounting hole mold rod (10), and the rear end diameter of the through hole is larger than the diameter of the limit head (11) of the mounting hole mold rod (10); the front end of the mounting hole mold rod (10) passes through the connecting plate (12); and the length of the mounting hole mold rod (10) is equal to the sum of the connection lengths of the insert (8) and the connecting plate (12); The top plate (3) is provided with a front slide bar (13), the bottom plate (6) is provided with a rear slide bar (14), the front slide bar (13) and the rear slide bar (14) are staggered, and the front mold fixing plate (1) and the rear mold fixing plate (4) are both provided with slide holes (15) for the front slide bar (13) and the rear slide bar (14); when the mold is closed, the front slide bar (13) and the rear slide bar (14) both pass through the front mold fixing plate (1) and the rear mold fixing plate (4); The front mold fixing plate (1) and the rear mold fixing plate (4) are respectively provided with a guide rod (16) and a guide hole (17), and the diameter of the guide hole (17) is larger than the diameter of the guide rod (16); Through holes corresponding to the connecting plate (12) are provided on both sides of the insert (8), and the front end of the mounting hole mold rod (10) passes through the insert (8); the insert (8) is in a "T"-shaped structure, and the front end of the insert (8) is thinner than the rear end, and the front end is narrower than the rear end.

2. The internal thread injection mold according to claim 1, characterized in that: The front mold core (2) is provided with a material feeding hole (18), a cooling hole (21) and a drainage groove (19), and the drainage groove (19) is connected to the threaded mold core.

3. The internal thread injection mold according to claim 1, characterized in that: The elastic member (20) is a spring having a spiral structure.

4. The demoulding method of the internal thread injection molded part according to any one of claims 1 to 3, characterized in that: It includes the following steps: Step 1: When the mold is closed, the rear mold moves toward the front mold. During the mold closing process, the mold closing accuracy is improved by means of the guide rods (16) and guide holes (17) respectively provided on the front mold fixing plate (1) and the rear mold fixing plate (4); when the threaded mold core (7) is placed in the injection mold cavity (9), the raw material is injected into the feed hole (18) through the feed hole (18) provided on the front mold core (2), and then the raw material is drained to the threaded mold core (7) through the drainage groove (19), so as to realize the rapid injection of the raw material; Step 2: When demoulding, the front mold and the rear mold are separated in opposite directions, and the rear mold drives the front mold to move in the direction of movement of the rear mold. At this time, the insert (8) moves backward in the thread mold core (7), thereby causing the thread mold core (7) to automatically move together. Due to the pulling action of the rear mold, the thread mold core (7) is withdrawn a certain distance before the installation hole mold rod (10), and then the installation hole mold rod (10) is withdrawn, so that the thread mold core (7) can realize automatic core pulling action when withdrawing from the injection mold cavity (9); Step 3: After the automatic core pulling action of step 2 is completed, the injection molded part is now bonded to the rear mold, and then the ejector pin provided on the rear mold bottom plate (6) is used to impact the injection molded part on the rear mold, thereby causing the injection molded part to fall off the rear mold core (5), thereby achieving automatic demoulding.

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