Side hole back-off injection molding rear mold of injection molding part

Abstract

The utility model relates to an injection molding piece side hole back-off injection molding rear mold which comprises a rear mold bottom plate, a rear mold cushion block, a rear mold plate, a rear mold core and a side forming block assembly, and the side forming block assembly comprises a mold closing wedge block, a sliding strip arranged on the rear mold plate, a guide block arranged on the side, facing the rear mold core, of the mold closing wedge block and a forming sliding block connected with the guide block in a sliding mode. The ends, facing the rear mold core, of the forming sliding block and the guide block are provided with side forming faces, the rear mold core is provided with a main forming face, the sliding direction of the forming sliding block points to the rear mold core and extends towards the rear portion of the center of the rear mold core, the side forming face at the end of the forming sliding block forms an inverted buckling part of a side hole of an injection molding part, and the side, away from the rear mold core, of the mold closing wedge block is provided with a mold closing inclined face. The forming slide block and the guide block are utilized to form the inverted buckle forming part of the side hole after mold closing, and the forming slide block and the guide block slide relatively in the demolding process to enable the end part of the forming slide block to contract backwards, so that the forming slide block is separated from an inverted buckle structure, and the inverted buckle structure is prevented from being damaged in the demolding process.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, and in particular to a post-injection mold with undercut side holes for injection molded parts. Background Technology

[0002] Because injection molded parts are lightweight, easy to mold, and have excellent physical properties, they are widely used. For some thin-walled parts with side holes, undercuts are set on the side holes. Therefore, using traditional forced removal methods can easily damage the undercuts. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a back mold for injection molding of side holes of injection molded parts with undercut.

[0004] The technical solution adopted by this utility model to solve its technical problem is: a back mold for injection molding of a side hole with undercut, including a back mold base plate, a back mold pad block disposed on the front side of the back mold base plate, a back mold plate disposed on the front side of the back mold pad block, a back mold core disposed on the front side of the back plate block, and a side forming block assembly that slides with the left and right rear plate blocks of the back mold core. The side forming block assembly includes a mold closing wedge block, a slide bar disposed on the back plate block, a guide block disposed on the side of the mold closing wedge block facing the back mold core, and a forming slider block slidably connected to the guide block. The forming slider block and the guide block are provided with a side forming surface at the end facing the back mold core. The back mold core is provided with a main forming surface. The sliding direction of the forming slider block points to the back mold core and extends to the rear of the center of the back mold core. The side forming surface at the end of the forming slider block forms the undercut portion of the side hole of the injection molding part. The mold closing wedge block is provided with a mold closing slope on the side away from the back mold core.

[0005] As a further improvement to this design, the mold clamping wedge is provided with a demolding clearance hole, and elastic pins extending into the demolding clearance hole are provided on both sides of the demolding clearance hole. The side of the elastic pin away from the rear mold core is provided with a pressing slope. When the elastic pin is in the fully extended state, the distance between the two elastic pins is less than the outer diameter of the inclined guide post on the front mold. When the elastic pin is in the retracted state, the distance between the two elastic pins is greater than the outer diameter of the inclined guide post on the front mold.

[0006] As a further improvement to this design, the rear template is provided with an elastic stop pin, and the rear side of the mold closing wedge has a stop groove that cooperates with the elastic stop pin. The stop groove engages with the elastic stop pin after the mold is opened, and the cross-section of the stop groove is V-shaped.

[0007] As a further improvement to this design, the guide block is provided with a guide boss with an isosceles trapezoidal cross section, the forming slider is provided with a dovetail groove that mates with the guide boss, the guide boss is provided with stop grooves on both sides, the forming slider is provided with stop claws that extend into the stop grooves, the mold clamping wedge is provided with a connecting groove that extends vertically, the guide block is provided with a connecting claw that mates with the connecting groove, and the connecting claws can slide along the direction of the connecting groove.

[0008] As a further improvement to this design, the front side of the rear template is provided with a mold core cavity to accommodate the rear mold core, and the left and right sides of the mold core cavity are provided with sliding cavities to accommodate the mold closing wedge block, and the slide bar is provided on the upper and lower sides of the sliding cavity.

[0009] As a further improvement to this design, an ejector plate that slides back and forth is provided between the rear mold base plate and the rear mold plate. The ejector plate is provided with ejector pins that penetrate forward through the rear mold plate and the rear mold core, and the ejector pins extend to the rear side of the main forming surface.

[0010] As a further improvement to this design, the mold clamping wedge is elastically connected to a demolding ejector pin. One end of the demolding ejector pin abuts against the molding slider at the end away from the rear mold core, and the demolding ejector pin applies a pushing force to the molding slider toward the rear mold core.

[0011] The beneficial effects of this utility model are: This utility model utilizes a molding slider and a guide block to form an undercut molding part with a side hole after the mold is closed. During the demolding process, the molding slider and the guide block slide relative to each other, causing the end of the molding slider to retract backward, thereby separating the molding slider from the undercut structure and avoiding damage to the undercut structure during demolding. Attached Figure Description

[0012] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0013] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model.

[0014] Figure 2 This is a schematic cross-sectional view of the present invention.

[0015] Figure 3 This utility model is in Figure 2 Enlarged schematic diagram at point I in the middle.

[0016] Figure 4 This is a three-dimensional structural diagram of the side-forming block assembly of this utility model.

[0017] Figure 5 This is a schematic diagram of the three-dimensional structure of the utility model, the inclined guide post, and the mold clamping block.

[0018] In the diagram: 1. Rear mold base plate, 2. Rear mold pad, 3. Rear template, 4. Elastic pin, 40. Pressure slope, 5. Mold closing slope, 6. Side forming block assembly, 60. Sliding bar, 61. Mold closing wedge, 610. Connecting groove, 62. Forming slider, 620. Dovetail groove, 621. Stop claw, 63. Guide block, 630. Guide boss, 631. Stopping groove, 632. Connecting claw, 7. Rear mold core, 8. Demolding clearance hole, 9. Stopping groove, 10. Ejector plate, 11. Mold core cavity, 12. Sliding cavity, 13. Ejector pin, 14. Demolding ejector pillar, 15. Side forming surface, 16. Main forming surface, 17. Angled guide pillar, 18. Mold closing pressure block. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions are only used to explain the present invention and are not intended to limit the present invention. Example

[0020] Please see Figure 1 , Figure 2 and Figure 3 This embodiment provides a back mold for injection molding of a side hole undercut, including a back mold base plate 1, a back mold pad 2 disposed on the front side of the back mold base plate 1, a back mold plate 3 disposed on the front side of the back mold pad 2, a back mold core 7 disposed on the front side of the back mold plate 3, and a side molding block assembly 6 that slides with the left and right sides of the back mold plate 3 of the back mold core 7. The side molding block assembly 6 includes a mold clamping wedge 61, a slide bar 60 disposed on the back mold plate 3, and a slide bar 60 disposed on the side of the mold clamping wedge 61 facing the back mold core 7. The guide block 63 and the molding slider 62 are slidably connected to the guide block 63. The molding slider 62 and the guide block 63 have a side molding surface 15 facing the rear mold core 7. The rear mold core 7 has a main molding surface 16. The sliding direction of the molding slider 62 is towards the rear mold core 7 and extends to the rear of the center of the rear mold core 7. The side molding surface 15 at the end of the molding slider 62 forms an undercut portion of the side hole of the injection molded part. The mold closing wedge 61 has a mold closing slope 5 on the side away from the rear mold core 7.

[0021] The aforementioned undercut molding part, which forms a side hole after the mold is closed using the molding slider 62 and the guide block 63, allows the molding slider 62 and the guide block 63 to slide relative to each other during the demolding process, causing the end of the molding slider 62 to retract backward, thereby separating the molding slider 62 from the undercut structure and avoiding damage to the undercut structure during demolding.

[0022] Please see Figure 1The mold opening drive of the mold clamping wedge 61 is achieved by using the inclined guide post 17 and the elastic pin 4. The structure is simple and the mold volume is reduced. The mold clamping wedge 61 is provided with a demolding clearance hole 8. On both sides of the demolding clearance hole 8, there are elastic pins 4 that extend into the demolding clearance hole 8. The side of the elastic pin 4 away from the rear mold core 7 is provided with a pressing slope 40. When the elastic pin 4 is in the fully extended state, the distance between the two elastic pins 4 is less than the outer diameter of the inclined guide post 17 on the front mold. When the elastic pin 4 is in the retracted state, the distance between the two elastic pins 4 is greater than the outer diameter of the inclined guide post 17 on the front mold.

[0023] Please see Figure 3 In order to ensure the stability of the mold closing wedge 61 after mold opening, the rear template 3 is provided with an elastic stop pin. The rear side of the mold closing wedge 61 has a stop groove 9 that cooperates with the elastic stop pin. The stop groove 9 engages with the elastic stop pin after mold opening. The cross-section of the stop groove 9 is V-shaped.

[0024] Please see Figure 4 To facilitate precise guidance and positioning of the forming slider 62, the guide block 63 is provided with a guide boss 630 having an isosceles trapezoidal cross-section. The forming slider 62 is provided with a dovetail groove 620 that mates with the guide boss 630. Stop grooves 631 are provided on both sides of the guide boss 630, and the forming slider 62 is provided with a stop claw 621 extending into the stop groove 631. The guiding and positioning structure of the forming slider 62 is simple and small in size. To facilitate the assembly and disassembly of the forming slider 62 and the guide block 63, the mold clamping wedge 61 is provided with a vertically extending connecting groove 610, and the guide block 63 is provided with a connecting claw 632 that mates with the connecting groove 610. The connecting claw 632 is slidable along the direction of the connecting groove 610.

[0025] Please see Figure 1 In order to facilitate the improvement of the connection strength between the rear mold core 7 and the rear template 3, the front side of the rear template 3 is provided with a mold core cavity 11 to accommodate the rear mold core 7, and the left and right sides of the mold core cavity 11 are provided with sliding cavities 12 to accommodate the mold closing wedge block 61, and the slide bar 60 is provided on the upper and lower sides of the sliding cavity 12.

[0026] Please see Figure 2 In order to facilitate the ejection and unloading of the injection molded parts, an ejector pin plate 10 that slides back and forth is provided between the rear mold base plate 1 and the rear mold plate 3. The ejector pin plate 10 is provided with ejector pins 13 that pass forward through the rear mold plate 3 and the rear mold core 7, and the ejector pins 13 extend to the rear side of the main molding surface 16.

[0027] Please see Figure 3To prevent the molding slider 62 from pulling on the undercut portion of the injection molded part at the start of demolding, the mold clamping wedge 61 is elastically connected to a demolding ejector pin 14. One end of the demolding ejector pin 14 abuts against the end of the molding slider 62 away from the rear mold core 7, and the demolding ejector pin 14 applies a pushing force to the molding slider 62 toward the rear mold core 7.

[0028] Please see Figure 5 During mold closing, the mold closing pressure block 18 on the front mold presses the mold closing wedge block 61 to slide towards the rear mold core 7. The forming slider 62 first contacts the rear mold core 7, and the mold closing wedge block 61 continues to move until the guide block 63 stops the rear mold core 7. During this process, the inclined guide post 17 of the front mold extends into the demolding clearance hole 8 and presses the elastic pin 4 to retract until the inclined guide post 17 passes between the two elastic pins 4.

[0029] During mold opening, the inclined guide post 17 pushes the elastic pin 4 laterally, which in turn pulls the mold closing wedge block 61 to slide away from the rear mold core 7. At the same time, the guide block 63 disengages from the rear mold core 7, and the molding slider 62 continues to abut against the rear mold core 7 and slides backward. The molding slider 62 separates from the undercut part of the injection molded part, and then the molding slider 62 follows the guide block 63 out. Finally, the ejector plate 10 moves forward and drives the ejector pin 13 to eject the injection molded part from the rear mold core 7 and unload it.

[0030] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A side gate undercut post-mold for injection molded parts, characterized in that, The application relates to a rear mold bottom plate, a rear mold cushion block arranged on the front side of the rear mold bottom plate, a rear mold plate arranged on the front side of the rear mold cushion block, a rear mold core arranged on the front side of the rear mold plate, and a side forming block assembly which is slidably connected with the rear mold plate on the left and right sides of the rear mold core.

2. A post-mold of injection-molded part side hole undercut injection molding according to claim 1, characterized in that, The mold wedge block is provided with a demolding avoiding hole, and elastic pins are arranged on the two sides of the demolding avoiding hole and extend into the demolding avoiding hole; the elastic pins are provided with pressing inclined surfaces on the sides away from the rear mold core; when the elastic pins are in the fully extended state, the distance between the two elastic pins is smaller than the outer diameter of the inclined guide column on the front mold; and when the elastic pins are in the retracted state, the distance between the two elastic pins is larger than the outer diameter of the inclined guide column on the front mold.

3. A post-mold of injection-molded part side hole undercut injection molding according to claim 2, characterized in that, The rear mold plate is provided with elastic stop pins, and the rear side of the mold wedge block is provided with a stop groove matched with the elastic stop pins; the stop groove is engaged with the elastic stop pins after the mold is opened; and the stop groove is V-shaped in cross section.

4. The post-mold of claim 3, wherein, The guide block is provided with a guide boss which is isosceles-trapezoidal in cross section; the forming slider is provided with a dovetail groove matched with the guide boss; the guide boss is provided with stop sliding grooves on the two sides; the forming slider is provided with stop claws extending into the stop sliding grooves; the mold wedge block is provided with a connecting groove extending upwards and downwards; the guide block is provided with connecting clamping claws matched with the connecting groove; and the connecting clamping claws are slidable along the connecting groove.

5. A side gate undercut post-mold of an injection molded part according to claim 4, characterized in that, The front side of the rear mold plate is provided with a mold core cavity accommodating the rear mold core; the left and right sides of the mold core cavity are provided with sliding cavities accommodating the mold wedge blocks; and the sliding strips are arranged on the upper and lower sides of the sliding cavities.

6. A side gate undercut post-mold of an injection molded part according to claim 5, characterized in that, The top pin plate is arranged to slide forward and backward between the rear mold bottom plate and the rear mold plate; the top pin plate is provided with top pins penetrating through the rear mold plate and the rear mold core in the forward direction; and the top pins extend to the rear side of the main forming surface.

7. The side gate undercut post-mold of claim 4, wherein, The mold wedge block is elastically connected with a demolding top column; one end of the demolding top column abuts against the end of the forming slider away from the rear mold core; and the demolding top column applies a pushing force to the forming slider towards the rear mold core.

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