A rotary core-pulling mechanism for avoiding insufficient strength

Abstract

The present invention belongs to the technical field of injection molds and relates to a rotary core-pulling mechanism that avoids insufficient strength. The mechanism comprises a housing, a drive head, a first core-pulling block, a second core-pulling block, a first connecting rod, and a second connecting rod. The first core-pulling block and the second core-pulling block both have an arc-shaped core-pulling portion, a lower shaft connection portion, and an outer shaft connection portion. The two lower shaft connections are both rotatably connected to the housing with the lower shaft as the center. The lower end of the first connecting rod is rotatably connected to the outer shaft connection portion of the first core-pulling block by a first outer shaft, and the lower end of the second connecting rod is rotatably connected to the outer shaft connection portion of the second core-pulling block by a second outer shaft. The housing comprises a front shell and a rear shell. The front shell is provided with a first arc-shaped waist hole and a second arc-shaped waist hole. The rear shell is provided with a third arc-shaped waist hole and a fourth arc-shaped waist hole. The first arc-shaped waist hole, the second arc-shaped waist hole, the third arc-shaped waist hole, and the fourth arc-shaped waist hole are all centered around the lower shaft. The present invention can distribute the driving force acting on the outer shaft connection portion through the two outer shafts, thereby avoiding the outer shaft connection portion from breaking.

Description

Technical Field

[0001] The invention relates to the technical field of injection molds, and in particular to a rotary core-pulling mechanism that avoids insufficient strength. Background Art

[0002] During injection molding, the molded product may have a hole-slot structure where the material removal direction is not in line with the mold opening direction. This requires a different core-pulling structure to achieve positioning and material removal during injection molding. If this hole-slot structure is an arc-shaped bend, it is often achieved by relying on a rotary core-pulling structure.

[0003] If the bend is large, a single core-pulling mechanism will not be able to successfully remove the material, and the mechanism is also susceptible to damage. Therefore, our company has designed a dual-link, dual-core-pulling mechanism to facilitate material removal. The principle is that the two core-pulling blocks are axially connected to the same position of the housing. The drive head pulls the two connecting rods, causing the two core-pulling blocks to rotate at opposite angles, and the two curved core-pulling sections are spliced ​​together to form a complete arc. However, the core-pulling block is a one-piece structure composed of the curved core-pulling section, the lower shaft connection, and the outer shaft connection, making it expensive to manufacture. The lower shaft connection is connected to the housing as two half-shafts, and due to the structural matching of the curved core-pulling section, the diameter of the lower shaft connection is very small, resulting in low strength. As the drive head extends and retracts, it inevitably applies force to the lower shaft connection. After repeated use, the lower shaft connection is prone to breakage, rendering the entire core-pulling block useless.

[0004] Therefore, it is necessary to develop a new core-pulling structure to solve the above problems. Summary of the Invention

[0005] The main purpose of the present invention is to provide a rotary core-pulling mechanism that avoids insufficient strength, can share the driving force acting on the rotating shafts of two core-pulling blocks, and improve the service life of the mechanism.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions: a rotary core-pulling mechanism that avoids insufficient strength, comprising a shell, a driving head, a first core-pulling block, a second core-pulling block, a first connecting rod and a second connecting rod, wherein the driving head is telescopic above the shell, the first core-pulling block and the second core-pulling block both have an arc-shaped core-pulling portion, a lower shaft connection portion and an outer shaft connection portion, the two lower shaft connections are both rotatably connected to the shell with the lower shaft as the center, the first connecting rod and the second connecting rod have the same length, the upper end of the first connecting rod and the upper end of the second connecting rod are rotatably connected to the driving head with the upper shaft as the center, the lower end of the first connecting rod is rotatably connected to the outer shaft connection portion of the first core-pulling block with the first outer shaft, and the second The lower end of the connecting rod is rotatably connected to the outer shaft connection of the second core-pulling block by the second outer shaft. The shell includes a front shell and a rear shell that are mirror-symmetrical. The two ends of the first outer shaft pass through the front shell and the rear shell respectively, and the two ends of the second outer shaft pass through the front shell and the rear shell respectively. The front shell is provided with a first arc-shaped waist hole that matches the rotation range of the first outer shaft and a second arc-shaped waist hole that matches the rotation range of the second outer shaft. The rear shell is provided with a third arc-shaped waist hole that matches the rotation range of the first outer shaft and a fourth arc-shaped waist hole that matches the rotation range of the second outer shaft. The first arc-shaped waist hole, the second arc-shaped waist hole, the third arc-shaped waist hole and the fourth arc-shaped waist hole all take the lower shaft as the axis.

[0007] Specifically, the lower shaft connecting portion of the first core pulling block and the lower shaft connecting portion of the second core pulling block are coaxially connected by a shaft rod.

[0008] Specifically, the inner side of the outer shaft connection portion of the first core pulling block has a first slope surface, and the inner side of the outer shaft connection portion of the second core pulling block has a second slope surface. When the first core pulling block and the second core pulling block are opened to the maximum angle, the first slope surface is in close contact with the second slope surface.

[0009] Furthermore, a ridge is provided in the middle of the first slope surface, and an avoidance groove matching the ridge is provided in the middle of the second slope surface.

[0010] Specifically, the two arc-shaped core-pulling parts are used to form a large arc, a groove is provided on the end face of the arc-shaped core-pulling part of the first core-pulling block, and a convex head matching the groove is provided on the end face of the arc-shaped core-pulling part of the second core-pulling block.

[0011] Specifically, a guide block is fixed to the lower part of the shell, and the guide block has a first guide hole matching the arc-shaped core-pulling portion of the first core-pulling block and a second guide hole matching the arc-shaped core-pulling portion of the second core-pulling block.

[0012] The beneficial effects of the technical solution of the present invention are:

[0013] The present invention can share the driving force acting on the outer shaft connection through two outer shafts, thereby avoiding the breakage of the outer shaft connection due to frequent driving and improving the service life of the mechanism. Although the two outer shafts increase wear, due to their simple structure and easy processing, even if they break, the replacement cost is relatively low, saving maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a three-dimensional diagram of the rotary core-pulling mechanism in the embodiment when the mold is closed;

[0015] Figure 2 An exploded view of the rotary core-pulling mechanism of an embodiment;

[0016] Figure 3 A three-dimensional diagram of the rotary core-pulling mechanism in the embodiment in the open state;

[0017] Figure 4 is a three-dimensional diagram of the first core pulling block;

[0018] Figure 5 It is a three-dimensional view of the second core pulling block.

[0019] The numbers in the figure represent:

[0020] 11-front shell, 111-first curved waist hole, 112-second curved waist hole, 12-back shell, 121-third curved waist hole, 122-fourth curved waist hole;

[0021] 2-driving head, 21-upper shaft;

[0022] 3a-first core pulling block, 3b-second core pulling block, 31-arc-shaped core pulling portion, 311a-groove, 311b-protrusion, 32-lower shaft connection portion, 33-outer shaft connection portion, 331-first slope, 332-ridge, 333-second slope, 334-avoidance groove;

[0023] 4a-first connecting rod, 4b-second connecting rod;

[0024] 5-guide block, 51-first guide hole, 52-second guide hole;

[0025] 6-axis rod;

[0026] 7a-first outer shaft, 7b-second outer shaft. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to specific embodiments.

[0028] Example:

[0029] like Figures 1 to 5As shown, a rotary core-pulling mechanism for avoiding insufficient strength of the present invention includes a shell, a driving head 2, a first core-pulling block 3a, a second core-pulling block 3b, a first connecting rod 4a and a second connecting rod 4b. The driving head 2 is telescopic above the shell. The first core-pulling block 3a and the second core-pulling block 3b both have an arc-shaped core-pulling portion 31, a lower shaft connection portion 32 and an outer shaft connection portion 33. The two lower shaft connections 33 are both rotatably connected to the shell with the lower shaft as the center. The first connecting rod 4a and the second connecting rod 4b have the same length. The upper ends of the first connecting rod 4a and the second connecting rod 4b are rotatably connected to the driving head 2 with the upper shaft 21 as the center. The lower end of the first connecting rod 4a is connected to the outer shaft connection portion 33 of the first core-pulling block 3a with the lower shaft connection portion 33. The first external shaft 7a is rotatably connected, and the lower end of the second connecting rod 4b is rotatably connected to the external shaft connection portion 33 of the second core pulling block 3b via the second external shaft 7b. The housing comprises a front shell 11 and a rear shell 12, both mirror-symmetrical. The front shell 11 is provided with a first curved waist hole 111 that matches the rotation range of the first external shaft 7a, and a second curved waist hole 112 that matches the rotation range of the second external shaft 7b. The rear shell 12 is provided with a third curved waist hole 121 that matches the rotation range of the first external shaft 7a, and a fourth curved waist hole 122 that matches the rotation range of the second external shaft 7b. The first, second, third, and fourth curved waist holes 111, 112, 121, and 122 all have their axes centered around the lower shaft. The first and second core pulling blocks 3a, 3b have similar overall structures and 180° symmetry in their movements. The drive head 2, the first and second core pulling blocks 3a, 3b, and the first and second connecting rods 4a, 4b form a quadrilateral linkage system with two diagonals perpendicular to each other. The two lower shaft connecting parts 32 are combined into a coaxial lower shaft. When the drive head 2 is extended or retracted, the first core pulling block 3a and the second core pulling block 3b rotate at the same angle and in opposite directions. That is, when the drive head 2 is raised, the first core pulling block 3a and the second core pulling block 3b are hidden in the shell. When the drive head 2 is lowered, the first core pulling block 3a and the second core pulling block 3b rotate symmetrically, and then the two arc-shaped core pulling parts 31 are combined into a large arc. In this way, a core pulling structure for forming a curved flow channel can be formed in the mold cavity, realizing the molding of the curved flow channel of the injection molded part. When the drive head 2 is extended and retracted, the driving force will be preferentially transmitted to the first outer shaft 7a and the second outer shaft 7b, and the shell will rely on the first arc-shaped waist hole 111 and the third arc-shaped waist hole 121 to share the push-pull force of the first outer shaft 7a, but will not affect the swing of the first core-pulling block 3a around the lower shaft; at the same time, the shell will rely on the second arc-shaped waist hole 112 and the fourth arc-shaped waist hole 122 to share the push-pull force of the second outer shaft 7b, but will not affect the swing of the second core-pulling block 3b around the lower shaft. Therefore, the radial force finally transmitted to the two lower shaft connecting parts 331 will be weakened, so that the lower shaft connecting parts 331 will not be broken due to frequent driving, thereby improving the service life of the mechanism. Although the first outer shaft 7a and the second outer shaft 7b increase wear, due to their simple structure and easy processing, even if they break, the replacement cost is relatively low, saving maintenance costs.

[0030] like Figure 2 As shown, the lower shaft connection 32 of the first core pulling block 3a is coaxially connected to the lower shaft connection 32 of the second core pulling block 3b by a shaft rod 6. Because the first and second core pulling blocks 3a and 3b rotate about the same axis, the two lower shaft connections 32 themselves are half shafts. After installation, they function as a single, complete shaft running through the front and rear shells 11 and 12, yet their relative rotation does not affect each other. The shaft rod 6 passes through the axial holes in the lower shaft connections 32, maintaining the two lower shaft connections 32 coaxially and improving structural stability.

[0031] like Figures 3 to 5 As shown, the inner side of the outer shaft connection portion 33 of the first core pulling block 3a has a first sloped surface 331, and the inner side of the outer shaft connection portion 33 of the second core pulling block 3b has a second sloped surface 333. When the first core pulling block 3a and the second core pulling block 3b are opened to their maximum angle, the first sloped surface 331 and the second sloped surface 333 are in close contact. The first sloped surface 331 and the second sloped surface 333 are used to limit the maximum opening of the first core pulling block 3a and the second core pulling block 3b. This prevents the first and second outer shafts 7a and 7b from prematurely colliding with the inner end of the arc-shaped waist hole, which in turn increases the load on the outer shaft connection portion 32, thereby protecting the integrity of the outer shaft connection portion 32.

[0032] like Figure 4 and Figure 5 As shown, a ridge 332 is provided in the middle of the first slope 331, and an avoidance groove 334 is provided in the middle of the second slope 333 to match the ridge 332. The ridge 332 and the avoidance groove 334 can achieve axial alignment of the first core pulling block 3a and the second core pulling block 3b when they are in close contact.

[0033] like Figure 4 and Figure 5 As shown, two arcuate core-pulling sections 31 are used to form a large arc. A groove 311a is provided on the end surface of the arcuate core-pulling section 31 of the first core-pulling block 3a, and a protrusion 211b is provided on the end surface of the arcuate core-pulling section 31 of the second core-pulling block 3b. When the two arcuate core-pulling sections 31 are joined, the groove 311a guides the protrusion 311b, ensuring a relatively even joint between the joined large arcs and preventing seams on the injection molded part.

[0034] like Figure 1 and Figure 2 As shown, a guide block 5 is provided at the lower portion of the housing. The guide block 5 has a first guide hole 51 that matches the arcuate core pulling portion 31 of the first core pulling block 3a, and a second guide hole 52 that matches the arcuate core pulling portion 31 of the second core pulling block 3b. The first guide hole 51 and the second guide hole 52 function in the same manner, both limiting the rotation of the arcuate core pulling portion 31 and preventing the first core pulling block 3a and the second core pulling block 3b from moving away from each other after contact.

[0035] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A rotary core-pulling mechanism to avoid insufficient strength, comprising a shell, a driving head, a first core-pulling block, a second core-pulling block, a first connecting rod and a second connecting rod, wherein the driving head is telescopic above the shell, the first core-pulling block and the second core-pulling block both have an arc-shaped core-pulling portion, a lower shaft connection portion and an outer shaft connection portion, the two lower shaft connections are both rotatably connected to the shell as the center of the lower shaft, the first connecting rod and the second connecting rod have the same length, the upper end of the first connecting rod and the upper end of the second connecting rod are rotatably connected to the driving head as the center of the upper shaft, the lower end of the first connecting rod is rotatably connected to the outer shaft connection portion of the first core-pulling block by the first outer shaft, and the lower end of the second connecting rod is rotatably connected to the outer shaft connection portion of the second core-pulling block by the second outer shaft, characterized in that: The shell includes a front shell and a rear shell that are mirror-symmetrical, two ends of the first outer shaft pass through the front shell and the rear shell respectively, and two ends of the second outer shaft pass through the front shell and the rear shell respectively. The front shell is provided with a first arc-shaped waist hole matching the rotation range of the first outer shaft and a second arc-shaped waist hole matching the rotation range of the second outer shaft. The rear shell is provided with a third arc-shaped waist hole matching the rotation range of the first outer shaft and a fourth arc-shaped waist hole matching the rotation range of the second outer shaft. The first arc-shaped waist hole, the second arc-shaped waist hole, the third arc-shaped waist hole and the fourth arc-shaped waist hole all take the lower shaft as the axis; the two arc-shaped core-pulling parts are used to form a large arc, and a groove is provided on the end face of the arc-shaped core-pulling part of the first core-pulling block, and a convex head matching the groove is provided on the end face of the arc-shaped core-pulling part of the second core-pulling block.

2. The rotary core-pulling mechanism for avoiding insufficient strength according to claim 1, characterized in that: The lower shaft connecting portion of the first core pulling block and the lower shaft connecting portion of the second core pulling block are coaxially connected via a shaft rod.

3. The rotary core-pulling mechanism for avoiding insufficient strength according to claim 1, characterized in that: The inner side of the outer shaft connection portion of the first core pulling block has a first slope surface, and the inner side of the outer shaft connection portion of the second core pulling block has a second slope surface. When the first core pulling block and the second core pulling block are opened to the maximum angle, the first slope surface is in close contact with the second slope surface.

4. The rotary core-pulling mechanism for avoiding insufficient strength according to claim 3, characterized in that: A ridge is provided in the middle of the first slope surface, and an avoidance groove matching the ridge is provided in the middle of the second slope surface.

5. The rotary core-pulling mechanism for avoiding insufficient strength according to claim 1, characterized in that: A guide block is fixed to the lower portion of the housing. The guide block has a first guide hole matching the arc-shaped core-pulling portion of the first core-pulling block and a second guide hole matching the arc-shaped core-pulling portion of the second core-pulling block.

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