A secondary strong release structure for cylindrical buckle in mold

Abstract

The present invention relates to a secondary forced demoulding structure of a cylindrical buckle position in a mold, comprising a fixed mold plate and a movable mold plate, a panel of the fixed mold plate is provided with a channel equipped with an elastic member, an ejector plate abutting against one end of the elastic member, and an ejector installed on the ejector plate, the elastic member ejects the ejector plate during demoulding, and moves forward a certain ejection distance; the movable mold plate comprises a return needle rod; the fixed mold plate also comprises a fixed mold insert, a first cylindrical sleeve sleeved in the fixed mold insert, and a second cylindrical sleeve sleeved in the first cylindrical sleeve, one end of the second cylindrical sleeve is provided with an outwardly convex buckle position, the first cylindrical sleeve and the second cylindrical sleeve are provided with a limiting structure, limiting the downward movement distance of the second cylindrical sleeve, and the ejection distance is greater than the downward movement distance; the ejector sleeve is in the second cylindrical sleeve. The present invention undergoes secondary demoulding by the ejector pin, and the product expands outward, which can ensure the stable structure of forced demoulding, avoid problems such as tearing or tearing due to forced demoulding, and also meet the requirements of product assembly.

Description

Technical Field

[0001] The invention relates to the field of mold demoulding structures, and more specifically to a secondary strong demoulding structure of a cylindrical buckle in a mold. Background Art

[0002] Storage box products are also common products in our daily life. There are four positions on the bottom of the box to be assembled with wheels. The mass production is more than one million times, so the stability of the mold is very important. The structure of the bottom plate of the storage box wheel products, please refer to the product Figure 1 , inner cylindrical buckle position as Figure 1 As shown in the reference numeral 13, the undercut space is narrow and the forced demolding method of core pulling and demolding using a conventional mold structure is prone to cause problems such as cracking at the buckle position of the product and inability to ensure assembly dimensions. Summary of the invention

[0003] In order to overcome at least one defect of the above-mentioned prior art, the present invention provides a demoulding solution for forced demoulding, which creates space for elastic deformation of plastic during forced demoulding, thereby avoiding problems such as cracking or dimensional deformation caused by general forced demoulding.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a secondary forced demoulding structure of a cylindrical buckle position in a mold, comprising a fixed template and a movable template, the panel of the fixed template is provided with a channel equipped with an elastic member, a pin plate abutting against one end of the elastic member and an ejector installed on the pin plate, the elastic member ejects the pin plate and moves forward a certain ejection distance during demolding; the movable template comprises a return pin rod, and the return pin rod resets the pin plate when the mold is closed; the fixed template also comprises a fixed mold insert, a first cylindrical sleeve sleeved in the fixed mold insert, and a second cylindrical sleeve sleeved in the first cylindrical sleeve, one end of the second cylindrical sleeve is provided with an outwardly convex buckle position, the first cylindrical sleeve and the second cylindrical sleeve are provided with a limiting structure to limit the downward movement distance of the second cylindrical sleeve; the ejector pin is sleeved in the second cylindrical sleeve; the ejection distance is greater than the downward movement distance.

[0005] The cavity surrounded by the first cylindrical sleeve, the second cylindrical sleeve and the ejector pin constitutes the cylindrical structure of the product. After the injection molding is completed, the product is formed in the cavity. At this time, the movable template begins to move downward. At this time, the elastic member pushes the ejector plate downward, driving the ejector pin and the second cylindrical sleeve to move downward with the product. After the second cylindrical sleeve reaches the position limited by the first cylindrical sleeve, it reaches the limit of the downward movement distance. At this time, the outer diameter of the product has been separated from the first cylindrical sleeve and has obtained space for outward expansion, but the product is still attached to the outer wall of the second cylindrical sleeve. Since the ejection distance is greater than the downward movement distance, the ejector plate drives the ejector pin to continue to eject for a distance. After reaching the limit of the ejection distance, the action stops, and the ejector pin ejects the product. The buckle position of the product is separated from the buckle position of the second cylindrical sleeve by expanding outward, achieving forced demolding.

[0006] The mold is reset, and the ejector plate is driven back to its original position by the return needle rod.

[0007] Preferably, the ejector pin and the second cylindrical sleeve share the same axial center line.

[0008] Preferably, the ejector pin is provided with a convex head at one end close to the second cylindrical sleeve, and the outer diameter of the convex head is smaller than the outer diameter of the buckle position. When the ejector pin is reset, the convex head abuts against the buckle position, and the second cylindrical sleeve can be reset together, thereby reducing the need for other auxiliary reset components.

[0009] Preferably, the ejector pin and the second cylindrical sleeve are in transitional fit, and the first cylindrical sleeve and the second cylindrical sleeve are in clearance fit. When the ejector pin moves downward, it fits tightly with the second cylindrical sleeve, making it easier to drive the second cylindrical sleeve to move downward together, while the second cylindrical sleeve and the first cylindrical sleeve are in clearance fit, avoiding friction with the first cylindrical sleeve and affecting movement.

[0010] Preferably, the movable template is provided with a return pin insert, and the return pin rod is mounted on the return pin insert. The return pin rod will be worn after a period of use. When the product has high requirements for stability, the specification size of the return pin rod needs to be maintained, and the return pin insert facilitates the replacement of the return pin rod.

[0011] Preferably, the fixed mold insert and the first cylindrical sleeve are in interference fit. The first cylindrical sleeve and the fixed mold insert are tightly matched to avoid downward movement during demoulding, resulting in the product not being able to escape from the first cylindrical sleeve and having insufficient space for outward expansion.

[0012] More preferably, the fixed mold insert is provided with a positioning step, and the first cylindrical sleeve is provided with a positioning protrusion that fits with the positioning step. The cooperation between the positioning step and the positioning protrusion can further prevent the first cylindrical sleeve from moving downward during demoulding.

[0013] Preferably, the elastic member is a mold spring.

[0014] Preferably, the limiting structure comprises a limiting hole provided in the first cylindrical sleeve, a limiting block provided on the second cylindrical sleeve or the other end, and the limiting block moves up and down in the limiting hole. The use of a simple limiting structure makes it more convenient to process and manufacture spare parts and replace and repair them.

[0015] More preferably, the limit block and the limit channel are spline-connected, which prevents the second cylindrical sleeve from rotating in the first cylindrical sleeve, thereby affecting product quality during injection molding.

[0016] Compared with the prior art, the invention has the following beneficial effects: the structure of the invention is simple and the space occupied in the mold is small; after the secondary demolding by the ejector pin, the product expands outward, which can ensure the stable structure and forced demolding, avoid problems such as cracking or tearing due to forced demolding, and thus meet the requirements of product assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the product structure;

[0018] Figure 2 It is a schematic diagram of the structure of the present invention;

[0019] Figure 3 yes Figure 2 A partial enlarged view of position A;

[0020] Figure 4 yes Figure 3 A partial enlarged view of position B.

[0021] Among them: 1. fixed template; 2. movable template; 3. elastic part; 4. ejector plate; 5. ejector; 501. convex head; 6. return needle rod; 7. fixed mold insert; 8. first cylindrical sleeve; 801. limiting channel; 9. second cylindrical sleeve; 901. limiting block; 902. buckle position; 10. return needle insert; 11. cavity; 12. product; 13. inner cylindrical buckle position. DETAILED DESCRIPTION

[0022] The drawings are only for illustrative purposes and cannot be construed as limiting the present invention. To better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are only for illustrative purposes and cannot be construed as limiting the present invention.

[0023] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "long", "short" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limitations on this patent. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0025] Example 1

[0026] like Figures 2 to 4 As shown, a secondary forced demoulding structure of a cylindrical buckle in a mold comprises a fixed mold plate 1 and a movable mold plate 2. The panel of the fixed mold plate 1 is provided with a channel equipped with an elastic member 3, an ejector plate 4 abutting against one end of the elastic member 3 and an ejector 5 installed on the ejector plate 4. The elastic member 3 ejects the ejector plate 4 and moves forward a certain ejection distance during demoulding; the movable mold plate 2 comprises a return needle rod 6, which resets the ejector plate 4 when the mold is closed. The fixed mold plate 1 also comprises a fixed mold insert 7, a first cylindrical sleeve 8 sleeved in the fixed mold insert 7, and a second cylindrical sleeve 9 sleeved in the first cylindrical sleeve 8. One end of the second cylindrical sleeve 9 is provided with an outwardly convex buckle position 902, and the first cylindrical sleeve 8 and the second cylindrical sleeve 9 are provided with a limiting structure to limit the downward movement distance of the second cylindrical sleeve 9; the ejector 5 is sleeved in the second cylindrical sleeve 9; the ejection distance is greater than the downward movement distance of the second cylindrical sleeve 9.

[0027] Furthermore, the ejector pin 5 and the second cylindrical sleeve 9 share the same axis. The ejector pin 5 and the second cylindrical sleeve 9 surround the shape of the product and move relative to each other. If the two do not share the same axis, they may deviate during the movement, affecting the molding of the product.

[0028] Furthermore, the ejector pin 5 is provided with a convex head 501 at one end close to the second cylindrical sleeve 9, and the outer diameter of the convex head 501 is smaller than the outer diameter of the buckle position. When the ejector pin 5 is reset, the convex head abuts against the buckle position, which can drive the second cylindrical sleeve 9 to reset together, thereby reducing the need for other auxiliary reset components.

[0029] Further, the movable template 2 is provided with a return needle insert 10, and the return needle rod 6 is installed on the return needle insert 10. The return needle rod will be worn after a period of use. When the product has high requirements for stability, it is necessary to maintain the specifications and dimensions of the return needle rod, and the return needle insert facilitates the replacement of the return needle rod.

[0030] Furthermore, the fixed mold insert 7 is interference fit with the first cylindrical sleeve 8. The first cylindrical sleeve is tightly matched with the fixed mold insert to avoid downward movement during demoulding, resulting in the product not being able to escape from the first cylindrical sleeve and having insufficient space for outward expansion.

[0031] Furthermore, the elastic member 3 is a mold spring.

[0032] Furthermore, the limiting structure includes a limiting hole 801 provided on the first cylindrical sleeve 8, a limiting block 901 provided on the second cylindrical sleeve 9 or the other end, and the limiting block 901 moves up and down in the limiting hole 901. The simple limiting structure makes it more convenient to manufacture spare parts and replace and repair them.

[0033] Furthermore, the limiting block 901 is spline-connected with the limiting hole 801. The spline connection prevents the second cylindrical sleeve from rotating in the first cylindrical sleeve, which would affect product quality during injection molding.

[0034] Example 2

[0035] The difference between this embodiment and the first embodiment is that, further, the ejector pin 5 and the second cylindrical sleeve 9 are transitionally matched, and the first cylindrical sleeve 8 and the second cylindrical sleeve 9 are clearance matched. When the ejector pin moves downward, it is closely fitted with the second cylindrical sleeve, which makes it easier to drive the second cylindrical sleeve to move downward together, while the second cylindrical sleeve and the first cylindrical sleeve are clearance matched to avoid friction with the first cylindrical sleeve and affect the movement.

[0036] Furthermore, the fixed mold insert 7 is provided with a positioning step, and the first cylindrical sleeve 8 is provided with a positioning protrusion that fits with the positioning step. The cooperation between the positioning step and the positioning protrusion further prevents the first cylindrical sleeve from moving downward during demoulding.

[0037] The working principle or workflow of the present invention is as follows: the cavity 11 surrounded by the first cylindrical sleeve 8, the second cylindrical sleeve 9 and the ejector 5 constitutes the cylindrical structure of the product. When the injection molding is completed, the product is formed in the cavity 11. At this time, the movable template 2 begins to move downward, and the elastic member 3 pushes the ejector plate 4 downward, driving the ejector 5 and the second cylindrical sleeve 9 to move downward with the product. After the second cylindrical sleeve 9 reaches the position limited by the first cylindrical sleeve 8, the outer diameter of the product has been separated from the first cylindrical sleeve 8, and space for outward expansion is obtained, but the product is still attached to the outer wall of the second cylindrical sleeve. Since the ejection distance is greater than the downward movement distance of the second cylindrical sleeve 9, the ejector plate 4 drives the ejector 5 to continue to eject for a distance. After reaching the limit of the ejection distance, the action stops, and the ejector 5 ejects the product. The buckle position of the product also breaks away from the buckle position of the second cylindrical sleeve 9 by expanding outward, thereby achieving forced demolding.

[0038] The mold is reset, and the ejector plate 4 is driven back to its original position by the return needle rod 6.

[0039] The structure of the invention is simple and occupies little space in the mold; after secondary demolding by the ejector pin, the product expands outward, which can ensure stable structure and forced demolding, avoid problems such as cracking or tearing due to forced demolding, and thus meet the requirements of product assembly.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A secondary forced demoulding structure for a cylindrical buckle in a mold, comprising a fixed mold plate (1) and a movable mold plate (2), wherein a panel of the fixed mold plate (1) is provided with a hole equipped with an elastic member (3), an ejector plate (4) abutting against one end of the elastic member (3), and an ejector (5) mounted on the ejector plate (4), wherein the elastic member (3) ejects the ejector plate (4) and moves forward a certain ejection distance during demoulding; the movable mold plate (2) comprises a return pin rod (6), wherein the return pin rod (6) resets the ejector plate (4) during mold closing, and is characterized in that: The fixed mold plate (1) further comprises a fixed mold insert (7), a first cylindrical sleeve (8) sleeved in the fixed mold insert (7), and a second cylindrical sleeve (9) sleeved in the first cylindrical sleeve (8), one end of the second cylindrical sleeve (9) being provided with an outwardly protruding buckle position (902), and the first cylindrical sleeve (8) and the second cylindrical sleeve (9) being provided with a limit structure for limiting the downward movement distance of the second cylindrical sleeve (9); the ejector pin (5) being sleeved in the second cylindrical sleeve (9); the ejection distance being greater than the downward movement distance; the ejector pin (5) being provided with a convex head (501) at one end close to the second cylindrical sleeve (9), and the outer diameter of the convex head (501) being smaller than the outer diameter of the buckle position (902); The movable template (2) is provided with a return pin insert (10), and the return pin rod (6) is mounted on the return pin insert (10); The fixed mold insert (7) and the first cylindrical sleeve (8) are in interference fit; The fixed die insert (7) is provided with a positioning step, and the first cylindrical sleeve (8) is provided with a positioning protrusion that fits with the positioning step.

2. A secondary forced release structure for cylindrical buckle in mold according to claim 1, characterized in that: The ejector pin (5) and the second cylindrical sleeve (9) share the same axis.

3. A secondary forced release structure for cylindrical buckle in mold according to claim 1 or 2, characterized in that: The ejector pin (5) and the second cylindrical sleeve (9) are in transition fit, and the first cylindrical sleeve (8) and the second cylindrical sleeve (9) are in clearance fit.

4. The secondary forced release structure of a cylindrical buckle in a mold according to claim 1, characterized in that: The elastic member (3) is a mold spring.

5. The secondary forced release structure of a cylindrical buckle in a mold according to claim 1, characterized in that: The limiting structure comprises a limiting hole (801) provided on the first cylindrical sleeve (8), and a limiting block (901) provided on or at the other end of the second cylindrical sleeve (9), wherein the limiting block (901) moves up and down in the limiting hole (801).

6. A secondary forced release structure for cylindrical buckle positions in a mold according to claim 5, characterized in that: The limiting block (901) and the limiting channel (801) are spline-connected.

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