Buffering ejection injection mold for plastic product

Abstract

According to the buffer ejection injection mold for the plastic product, when injection molding is completed and demolding is conducted, a push plate drives an ejector rod to eject out the formed plastic product, a buffer ejection assembly arranged at the end of the ejector rod can achieve the buffer ejection effect on the formed plastic product, that is, the ejector rod ejects out and pushes a buffer spring of the buffer ejection assembly; when the ejection head is in contact with the plastic product, the molded plastic product exerts counter-acting force on the ejection head, so that the sliding rod drives the limiting plate to exert acting force on the buffer spring, and the buffer spring is compressed to generate elastic deformation; the forced ejection force of the ejection head on the molded plastic product is reduced, so that the ejection head can apply light elastic buffering force to the molded plastic product in the initial stage of demolding so as to softly separate the molded plastic product from the surface of the lower mold core, and the surface damage or deformation of the product caused by forced ejection demolding of the ejection head is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of injection molds, and in particular to an injection mold with buffer ejection for plastic products. Background Art

[0002] Injection molds are critical tools for producing plastic products, widely used in the manufacturing of a wide range of industrial and consumer products. The basic principle of injection molds is to inject molten plastic material into a mold cavity through an injection molding machine, allowing it to cool and solidify into the desired shape. Typically, an injection mold consists of an upper mold assembly and a lower mold assembly. The mechanical action of the injection molding machine allows the mold to be quickly opened and closed, completing the production of plastic products.

[0003] The main components of an injection mold include the mold shell, mold cavity, mold core, runner system, cooling system, ejector pins, and base plate. These components work together to ensure that the plastic melt flows evenly into the mold cavity under high pressure and forms the desired plastic product after cooling. After injection molding, the plastic product is typically ejected from the mold using an ejector system.

[0004] In the production of large-scale plastic products, such as washing machine parts, conventional technology typically uses an ejector system to forcibly eject the molded product. However, because the surface temperature of the plastic product has not yet completely cooled after injection molding, there is a certain degree of adhesion between the plastic product and the inner wall of the mold core. Forced ejection can easily cause surface damage or deformation of the product. This deformation not only affects the product's appearance but can also reduce its functionality and dimensional accuracy, increasing scrap rates and production costs.

[0005] In order to avoid the above problems, there is a need for an ejection structure of an injection mold that can effectively reduce the impact force during the ejection process and reduce damage to the plastic product during the demoulding process. Utility Model Content

[0006] In view of the shortcomings of the existing technology, the purpose of this application is to provide an injection mold with buffer ejection for plastic products to solve the problems raised in the above background technology.

[0007] According to one aspect of the present application, an injection mold for plastic products with buffered ejection comprises an upper mold, an upper mold core, a lower mold, a lower mold core and an ejector pin, an upper template is installed on the top of the upper mold, an upper mold core is embedded in the middle of the bottom surface of the upper mold, the bottom surface of the upper mold is tightly assembled with the top surface of the lower mold, and the lower mold core is embedded in the middle of the top surface of the lower mold, and a closed molding cavity is formed between the middle of the bottom surface of the upper mold core and the middle of the top surface of the lower mold core, and the molding cavity is used to mold plastic products, a supporting base is installed at the bottom of the lower mold, a plurality of ejector pins are installed on the supporting base, and the upper end of each ejector pin slides through the lower mold and the lower mold core in sequence from bottom to top through a through hole, and a buffered ejection assembly is installed on the upper end of each ejector pin, and the buffered ejection assembly is elastically connected to the top of the ejector pin, and the buffered ejection The cam is secured to the upper edge of the sliding member with a spring that is secured to the lower edge of the sliding member with respect to the cam.

[0008] Preferably, the support base includes a support side plate, a push plate, a return spring and a lower mold. Support side plates are installed on both sides of the bottom surface of the lower mold. The lower mold is installed on the bottom surface of the support side plate. A push plate is arranged above the lower mold. The push plate is fixedly connected to the lower end of the push rod, and a return spring is fixedly provided between the push plate and the lower mold.

[0009] Preferably, when the push plate drives the bottom of the ejector rod to move to the lowermost end of the support base, the top surface of the ejector head is flush with the top surface of the lower mold core, and the limiting plate slides to conflict with the limiting cap.

[0010] Preferably, a limiting groove is provided at the peripheral side of the upper end of the through hole in the lower mold core, and the peripheral size of the limiting groove is larger than the peripheral size of the through hole, and the peripheral side shape of the limiting groove is adapted to the peripheral side shape of the ejector head.

[0011] Preferably, the inner circumference of the limiting groove and the outer circumference of the ejector head are both in the shape of an inverted truncated cone.

[0012] Preferably, the limiting cap is fixedly installed on the inner upper end of the accommodating groove by a threaded connection, a threaded hole is opened through the center of the limiting plate and is fixedly connected to the sliding rod by a thread, and a positioning shoulder is provided on the sliding rod at the connection position of the limiting plate.

[0013] Preferably, a sliding groove is provided at the bottom of the accommodating groove along the axis direction of the sliding rod, and the lower end of the sliding rod is slidably arranged in the sliding groove.

[0014] The advantages of the present application over the prior art are: an injection mold for plastic products with buffer ejection of the present application, through the buffer ejection assembly arranged at the end of the ejector rod, when the injection molding is completed and the mold is demolded, the push plate drives the ejector rod to eject the molded plastic product, and the buffer ejection assembly arranged at the end of the ejector rod can play a buffer ejection role for the molded plastic product, that is, the ejector rod pushes the buffer spring of the buffer ejection assembly during sliding ejection, so that it presses against the limit plate and drives the ejector head at the end of the sliding rod to eject the molded plastic product. When the ejector head contacts the plastic product, the molded plastic product applies a reaction force to the ejector head, thereby causing the sliding rod to drive the limit plate to apply a force to the buffer spring, thereby compressing the buffer spring to cause elastic deformation, thereby reducing the forced ejection force of the ejector head on the molded plastic product, thereby enabling the ejector head to apply a lighter elastic buffer force to the molded plastic product in the initial stage of demolding so that it is gently separated from the surface of the lower mold core, thereby avoiding damage or deformation of the product surface caused by forced ejection and demolding of the ejector head. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of an injection mold for plastic products with buffer ejection after mold closing according to one embodiment of the present application.

[0016] Figure 2 This is a schematic structural diagram of an injection mold for plastic products with buffer ejection after mold opening according to an embodiment of the present application.

[0017] Figure 3 yes Figure 1 A schematic diagram of the structure of the middle part A.

[0018] Figure 4 yes Figure 2 Schematic diagram of the enlarged structure of part B in the middle.

[0019] Figure 5 This is a three-dimensional exploded view of a buffer ejection component of an injection mold for buffer ejection of plastic products according to one embodiment of the present application.

[0020] Figure numerals: 1. upper mold; 2. upper mold core; 3. lower mold; 4. lower mold core; 5. ejector rod; 51. receiving groove; 52. sliding groove; 6. molding cavity; 7. supporting base; 71. supporting side plate; 72. push plate; 73. reset spring; 74. lower template; 8. through hole; 81. limiting groove; 9. buffer ejection assembly; 91. sliding rod; 92. ejection head; 93. limiting cap; 931. sliding hole; 94. limiting plate; 95. buffer spring. DETAILED DESCRIPTION

[0021] In order to make the content of this application easier to understand, the technical solutions in the embodiments of this application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of this application. It should be noted that the words "front", "back", "left", "right", "up" and "down" used in the following description refer to the attached drawings. Figure 1 As used herein, the terms "inward" and "outward" refer to directions toward and away from, respectively, the geometric center of the particular component.

[0022] like Figures 1 to 5As shown, an injection mold for plastic products with buffer ejection includes an upper mold 1, an upper mold core 2, a lower mold 3, a lower mold core 4 and an ejector rod 5. The upper mold 1 is installed with an upper template on the top, the upper mold 1 is embedded with the upper mold core 2 in the middle of the bottom surface, the bottom surface of the upper mold 1 and the top surface of the lower mold 3 are tightly assembled, the lower mold core 4 is embedded in the middle of the top surface of the lower mold 3, and the middle of the bottom surface of the upper mold core 2 and the middle of the top surface of the lower mold core 4 form a closed molding cavity 6. The molding cavity 6 is used to mold plastic products. The bottom of the lower mold 3 is installed with a support base 7. The support base 7 includes a support side plate 71, a push plate 72, and a return spring 73. And the lower template 74, the bottom surface of the lower mold 3 is equipped with supporting side plates 71 on both sides, the bottom surface of the supporting side plates 71 is equipped with a lower template 74, and a push plate 72 is provided above the lower template 74. The push plate 72 is fixedly connected to the lower ends of multiple ejector rods 5, and a return spring 73 is fixedly provided between the push plate 72 and the lower mold 3; the upper end of each ejector rod 5 slides through the lower mold 3 and the lower mold core 4 from bottom to top through the through hole 8 in sequence, and a buffer ejection assembly 9 is installed on the upper end of each ejector rod 5. The buffer ejection assembly 9 is elastically connected to the top of the ejector rod 5. Specifically, the buffer ejection assembly 9 includes a sliding rod 91, an ejection head 9 2. Limiting cap 93, limiting plate 94 and buffer spring 95. The center of the upper end of the top rod 5 is recessed to open a receiving groove 51. The upper end of the receiving groove 51 is fixedly installed with the limiting cap 93 by threaded connection. The middle of the limiting cap 93 is penetrated by a sliding hole 931. The middle of the sliding rod 91 slides in the sliding hole 931. The upper part of the sliding rod 91 is set in the through hole 8 and the lower part of the sliding rod 91 is set in the receiving groove 51. The middle part of the sliding rod 91 is provided with an external thread. The center of the limiting plate 94 is penetrated by a threaded hole and is fixedly connected to the sliding rod 91 by a thread, so that the limiting plate 9 4 can slide synchronously with the sliding rod 91, and a positioning shoulder is provided on the sliding rod 91 at the connection position of the limit plate 94 to facilitate the installation of the limit plate 94 on the sliding rod 91. The limit plate 94 is slidably arranged in the receiving groove 51, and a buffer spring 95 is provided in the receiving groove 51. The upper and lower ends of the buffer spring 95 respectively conflict with the limit plate 94 and the bottom of the receiving groove 51. In addition, a sliding groove 52 is opened at the bottom of the receiving groove 51 along the axial direction of the sliding rod 91. The lower end of the sliding rod 91 is slidably arranged in the sliding groove 52. This arrangement can make the sliding rod 91 slide more stably.An ejector head 92 is fixed to the upper end of the sliding rod 91. The top surface shape of the ejector head 92 is adapted to the shape of the corresponding portion of the top surface of the lower mold core 4. A limiting groove 81 is provided on the circumferential side of the upper end of the through hole 8 in the lower mold core 4. The circumferential side size of the limiting groove 81 is larger than the circumferential side size of the through hole 8. The shape and size of the circumferential side of the limiting groove 81 are adapted to the shape and size of the circumferential side of the ejector head 92. The inner circumferential side shape of the limiting groove 81 and the outer circumferential side shape of the ejector head 92 are both inverted truncated cone shapes. After the mold is assembled, when the push plate 72 drives the bottom of the ejector rod 5 to move to the lowest end of the support base 7, the outer circumference of the ejector head 92 is in close contact with the inner circumference of the limiting groove 81, and the top surface of the ejector head 92 is flush with the top surface of the lower mold core 4. At this time, the buffer spring 95 is in a slightly compressed state and slides against the limiting plate 94 until it contacts the limiting cap 93. The limiting groove 81 can limit the ejector head 92, preventing the ejector head 92 from sinking into the through hole 8 and affecting the molding quality of the plastic product.

[0023] In the specific implementation, the process of installing the buffer ejection assembly 9 to the ejector rod 5 is as follows: install the ejector rod 5 on the push plate 72, then pass the ejector rod 5 through the lower mold 3 and the lower mold core 4 through the through hole 8, and make the upper end of the ejector rod 5 pass through the top of the lower mold core 4, then place the buffer spring 95 in the receiving groove 51 at the upper end of the ejector rod 5, then first put the limit cap 93 from the lower end of the sliding rod 91 on its outside and slide it to the upper part, then fix the limit plate 94 on the sliding rod 91 through a threaded connection, and insert the sliding rod 91 into the receiving groove 51, so that the lower end of the sliding rod 91 slides into the sliding groove 52, and makes the limit plate 94 conflict with the upper end of the buffer spring 95, then fix the limit cap 93 to the upper end of the ejector rod 5 through a threaded connection, and then the buffer ejection assembly 9 is installed.

[0024] During the installation of the injection mold, the upper template is fixedly installed on the injection molding part of the injection molding machine as a fixed mold, and an ejection through hole is also provided on the lower template 74. The lower template 74 is fixedly installed on the moving part (hydraulic cylinder or screw) of the injection molding machine as a movable mold, and the ejection rod of the ejection part (hydraulic cylinder) of the injection molding machine passes through the ejection through hole of the lower template 74 and contacts the push plate 72.

[0025] When the ejector 92 is in contact with the plastic product, the molded plastic product exerts a reaction force on the ejector 92, thereby causing the sliding rod 91 to drive the limiting plate 94 to exert a force on the buffer spring 95, thereby compressing the buffer spring 95 and causing the buffer spring 95 to elastically deform, thereby reducing the forced ejection force of the ejector 92 on the molded plastic product, thereby enabling the ejector 92 to apply a lighter elastic buffering force to the molded plastic product in the initial stage of demoulding, so that it is gently separated from the surface of the lower mold core 4, thereby avoiding forced ejection and demoulding of the ejector 92 and causing damage or deformation to the product surface.

[0026] The above embodiments are intended only to illustrate the technical solutions of the embodiments of the present application and are not intended to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned embodiments, it should be understood by those skilled in the art that, without departing from the spirit and scope defined by the claims of the present application, they may still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents.

Claims

1. An injection mold for plastic products with buffer ejection, comprising an upper mold (1), an upper mold core (2), a lower mold (3), a lower mold core (4) and a push rod (5), wherein an upper mold plate is installed on the top of the upper mold (1), an upper mold core (2) is embedded in the middle of the bottom surface of the upper mold (1), the bottom surface of the upper mold (1) and the top surface of the lower mold (3) are tightly assembled, and a lower mold core (4) is embedded in the middle of the top surface of the lower mold (3), and the middle of the bottom surface of the upper mold core (2) and the middle of the top surface of the lower mold core (4) form a closed molding cavity (6), and the molding cavity (6) is used to mold plastic products, and a support base (7) is installed on the bottom of the lower mold (3), and a plurality of push rods (5) are installed on the support base (7), and the upper end of each push rod (5) slides through the lower mold (3) and the lower mold core (4) in sequence from bottom to top through a through hole (8), characterized in that A buffer ejection assembly (9) is installed on the upper end of each push rod (5), and the buffer ejection assembly (9) is elastically connected to the top of the push rod (5). The buffer ejection assembly (9) includes a sliding rod (91), an ejection head (92), a limiting cap (93), a limiting plate (94) and a buffer spring (95). A receiving groove (51) is provided on the upper end of the push rod (5), and a limiting cap (93) is fixedly installed on the upper end of the receiving groove (51). A sliding hole (931) is provided through the middle of the limiting cap (93), and the middle of the sliding rod (91) is slidably arranged in the sliding hole (931). The upper part of the sliding rod (91) is arranged in the through hole (8) and the sliding The lower part of the rod (91) is arranged in the accommodating groove (51), and a limiting plate (94) is fixedly installed in the middle part of the sliding rod (91), and the limiting plate (94) is slidably arranged in the accommodating groove (51). A buffer spring (95) is arranged in the accommodating groove (51), and the upper and lower ends of the buffer spring (95) respectively conflict with the limiting plate (94) and the bottom of the accommodating groove (51). The upper end of the sliding rod (91) is fixed with an ejector head (92), and the top surface shape of the ejector head (92) is adapted to the shape of the corresponding part of the top surface of the lower mold core (4). When the injection mold is assembled, the top surface of the ejector head (92) is flush with the top surface of the lower mold core (4).

2. The injection mold with buffer ejection for plastic products according to claim 1, characterized in that: The support base (7) includes a support side plate (71), a push plate (72), a return spring (73) and a lower mold (74). Support side plates (71) are installed on both sides of the bottom surface of the lower mold (3). The bottom surface of the support side plate (71) is installed with a lower mold (74). A push plate (72) is arranged above the lower mold (74). The push plate (72) is fixedly connected to the lower end of the push rod (5). A return spring (73) is fixedly arranged between the push plate (72) and the lower mold (3).

3. The injection mold with buffer ejection for plastic products according to claim 2, characterized in that: When the push plate (72) drives the bottom of the ejector rod (5) to move to the lowermost end of the support base (7), the top surface of the ejector head (92) is flush with the top surface of the lower mold core (4), and the limiting plate (94) slides until it contacts the limiting cap (93).

4. The injection mold with buffer ejection for plastic products according to claim 3, characterized in that: A limiting groove (81) is provided at the circumferential side of the upper end of the through hole (8) in the lower die core (4), and the circumferential side size of the limiting groove (81) is larger than the circumferential side size of the through hole (8), and the circumferential side shape and size of the limiting groove (81) are compatible with the circumferential side shape and size of the ejector head (92).

5. The injection mold with buffer ejection for plastic products according to claim 4, characterized in that: The inner peripheral shape of the limiting groove (81) and the outer peripheral shape of the ejector head (92) are both in the shape of an inverted truncated cone.

6. The injection mold with buffer ejection for plastic products according to claim 1, characterized in that: The limiting cap (93) is fixedly mounted on the inner upper end of the accommodating groove (51) through a threaded connection, a threaded hole is provided through the center of the limiting plate (94) and is fixedly connected to the sliding rod (91) through a threaded connection, and a positioning shoulder is provided on the sliding rod (91) at the connection position of the limiting plate (94).

7. The injection mold with buffer ejection for plastic products according to claim 1, characterized in that: A sliding groove (52) is provided at the bottom of the accommodating groove (51) along the axial direction of the sliding rod (91), and the lower end of the sliding rod (91) is slidably arranged in the sliding groove (52).

Images