CN105666782A - In-mold extrusion device - Google Patents

Abstract

The invention discloses an in-mold extrusion device which comprises an extrusion sliding block, a toggle mechanism, an oil cylinder and an extrusion control device, wherein the extrusion sliding block is telescopically arranged in a sliding hole, the extrusion sliding block is connected with a telescopic rod of the oil cylinder through the toggle mechanism, and the extrusion control device is used for controlling the telescopic motion of the oil cylinder; the oil cylinder extends or retracts to drive the toggle mechanism to straighten or bend, so that the extrusion sliding block extends or retracts. According to the in-mold extrusion device provided by the invention, the extrusion sliding block is connected with the oil cylinder through the toggle mechanism, and the toggle mechanism can amplify the force by 20 times or more, so that the huge injection pressure is overcome, and the problem of insufficient driving force is solved. And, the hydraulic cylinder stroke is short when bending the elbow structure and unbending, and ordinary oil pressure system can all accomplish, and reaction rate is little to moulding plastics influence, and control is easier.

Description

In-mold extrusion device

technical field

The invention relates to the technical field of injection molding, in particular to an in-mold extrusion device.

Background technique

At present, some plastic products have relatively large areas of ultra-thin wall thickness (such as ABS materials with an average of 2.5 mm or more and some parts below 1.2 mm), and such ultra-thin position molding cannot be realized in conventional injection molding production technology. A possible molding solution——steam molding technology, but steam molding technology requires additional steam equipment plant line transformation, etc. If it is not popularized and applied in large quantities, there will be disadvantages such as high mold costs, low production efficiency, and very high costs , and the ultra-thin area in production is still very difficult to punch, the injection molding process is difficult to debug, and the thickness of the thin wall is unstable.

In order to solve the above problems, Chinese patent (CN105034244A) discloses a secondary molding mechanism for thin-walled low-pressure injection molding. The secondary molding device of the molding mechanism includes a top block and an oil cylinder. The upper movement completes the second shaping action. The oil cylinder of the molding mechanism directly drives the jack block. Since the pressure of the oil cylinder is usually only about 10MPA, and for ultra-thin products (thickness below 1.2mm), the injection pressure on the jack block during the compression process is very large (usually up to 60-100MPA), The driving force of the oil cylinder is seriously insufficient.

Contents of the invention

In view of the above-mentioned current state of the art, the present invention provides an in-mold extrusion device to solve the problem of insufficient driving force.

In order to solve the above technical problems, an in-mold extrusion device provided by the present invention includes an extrusion slider, a toggle mechanism, an oil cylinder and an extrusion control device, and the extrusion slider is telescopically installed in the slide hole , the extrusion slider is connected with the telescopic rod of the oil cylinder through the toggle mechanism, the extrusion control device is used to control the telescopic movement of the oil cylinder; the oil cylinder extends or retracts to drive the toggle mechanism Straighten or bend, so that the squeeze slider is extended or retracted.

In one of the embodiments, the elbow mechanism includes a first elbow flexion arm, a second elbow flexion arm and an elbow seat, and the first end of the first elbow flexion arm is connected to the first elbow flexion shaft through the first elbow flexion shaft. The tail of the extrusion slider is hinged, the second end of the first elbow flexion arm is hinged with the first end of the second elbow flexion arm through the second elbow flexion shaft, and the second end of the second elbow flexion arm is passed through The third elbow flexion shaft is hinged with the elbow seat, and the second elbow flexion shaft is connected with the telescopic rod of the oil cylinder.

In one of the embodiments, between the first end of the first elbow flexion arm and the tail of the extrusion slider, between the second end of the first elbow flexion arm and the second elbow flexion arm The first ends of the rotating arms and the second end of the second elbow bending arm and the elbow seat are fitted with convex and concave arc surfaces, so that the elbow mechanism bears pressure through the arc surfaces when straightening.

In one of the embodiments, the end surface of the first end of the first elbow flexion arm is a first convex circular arc surface, and the tail of the extrusion slider is provided with the first convex circular arc surface. The arc surface matches the concave first concave arc surface, the end face of the second end of the first elbow flexion arm is a convex second convex arc surface, and the second elbow flexion arm’s first One end is provided with a concave second inner concave arc surface matching the second outer convex arc surface, and the end surface of the second end of the second elbow flexion arm is a third outer convex arc surface that is outwardly convex surface, and the elbow flexion seat is provided with a third inner concave arc surface matched with the third outer convex arc surface.

In one of the embodiments, the tail of the extrusion slider, the second end of the first elbow flexion arm and the first end of the second elbow flexion arm are all fork-shaped, and the first The first end of the elbow flexion arm is located between the two forks of the forked tail of the squeeze slider, and the second end of the first elbow flexion arm is located at the fork of the second elbow flexion arm between the two forks at the first end of the shape.

In one of the embodiments, the in-mold extrusion device further includes an extrusion link, one end of the extrusion link is connected to the second elbow flexion shaft, and the other end of the extrusion link is connected to the The telescopic rod connection of the above oil cylinder.

In one embodiment, the sliding hole is T-shaped, and the extruding slider is T-shaped matching the T-shaped sliding hole.

In one of the embodiments, the extrusion control device includes:

a controller, the signal input end of the controller is connected to the injection signal output end of the injection molding machine, and is used to receive the injection signal from the injection molding machine and generate a control signal; and

A hydraulic valve, the hydraulic valve is used to control the extension or retraction of the oil cylinder, the group A coils and the group B coils of the hydraulic valve are respectively connected to the signal output ends of the controller.

In one of the embodiments, the extrusion control device further includes an upper stroke switch of the mold, a stroke switch lever and an indicator light, the stroke switch lever moves synchronously with the telescopic rod of the oil cylinder, and the upper stroke switch is installed at the stroke One side of the switch lever is connected with the controller, and the indicator light is connected with the controller.

Compared with the prior art, in the in-mold extrusion device provided by the present invention, the extrusion slider is connected with the oil cylinder through the toggle mechanism, and the toggle mechanism can amplify the force by 20 times or more, thereby overcoming the huge injection pressure and solving the problem of The problem of insufficient drive. Moreover, when the elbow is bent and straightened, the stroke of the hydraulic cylinder is short, which can be achieved by ordinary hydraulic systems. The reaction speed has little effect on injection molding, and the control is easier.

The beneficial effects of the additional technical features of the present invention will be described in the specific embodiments of this specification.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the thin-walled product injection mold in the embodiment of the present invention;

Fig. 2 is the top structural schematic diagram of the thin-wall product injection mold in the embodiment of the present invention;

Fig. 3 is a sectional view along line A-A in Fig. 2;

Fig. 4 is a three-dimensional structural schematic view of the elbow mechanism of the in-mold extrusion device in the embodiment of the present invention when it is bent;

Fig. 5 is a schematic diagram of the front view of the toggle mechanism of the in-mold extrusion device in the embodiment of the present invention when it is bent;

Fig. 6 is a right view structural diagram of the toggle mechanism of the in-mold extrusion device in the embodiment of the present invention when it is bent;

Fig. 7 is a sectional view along the line B-B in Fig. 6;

Fig. 8 is a schematic diagram of the front view of the toggle mechanism of the in-mold extrusion device in the embodiment of the present invention when it is bent and straightened;

Fig. 9 is a schematic cross-sectional structural view of the toggle mechanism of the in-mold extrusion device in an embodiment of the present invention when it is bent and straightened;

Fig. 10 is a schematic diagram of the extrusion control device in the embodiment of the present invention.

Explanation of reference signs: 1. Oil cylinder; 2. Oil cylinder fixing seat; 3. Travel switch; 4. Travel switch lever; 5. Extrusion connecting rod; 6. Extrusion slider; 6a, first concave arc surface ; 6b, extruding the end face of the slider head; 7, the product; 8, the first elbow flexion arm; 8a, the first convex arc surface; 8b, the second convex arc surface; 9, the first flex Elbow shaft; 10, elbow seat; 10a, third concave arc surface; 11, moving mold core; 11a, sliding hole; 11b, forming surface; 11c, elbow accommodation chamber; 12, elbow mechanism; 13, The second elbow flexion arm; 13a, the second concave arc surface; 13b, the third convex arc surface; 14, the second elbow flexion shaft; 15, the third elbow flexion shaft; 20, extrusion control device; 21. Controller; 22. Hydraulic valve; 23. Indicator light.

detailed description

The present invention will be described in detail below with reference to the accompanying drawings and examples. It should be noted that, in the case of no conflict, the following embodiments and features in the embodiments can be combined with each other.

As shown in Figures 1-3, the injection mold for thin-walled products in one of the embodiments of the present invention includes a movable mold core 11, a fixed mold core (not shown) and an in-mold extrusion device, and the molding of the movable mold core 11 The surface 11b cooperates with the molding surface of the fixed mold core to form a mold core cavity, and a T-shaped sliding hole 11a is arranged on the movable mold core 11, and the orifice of the sliding hole 11a is located on the molding surface 11b of the movable mold core 11. Preferably, the movable mold core 11 is also provided with a toggle accommodation cavity 11c.

The in-mold extrusion device includes an extrusion slider 6, a toggle mechanism 12, an extrusion connecting rod 5, an oil cylinder 1 and an extrusion control device 20, wherein the extrusion slider 6 is connected to the T on the movable die core 11. T-shape matching the sliding hole 11a, the extruding slider 6 is telescopically installed in the sliding hole 11a. When the squeeze slider 6 is retracted, the end face 6b of the head of the squeeze slider 6 is retracted into the slide hole 11a at a set distance L (as shown in FIG. 3 ), and L is preferably 2.5mm to 3.5mm; When the extruding slider 6 stretched out, the end face 6b of the head of the extruding slider 6 was flush with the forming surface 11b of the movable die core 11 . The tail of the extruding slider 6 is fork-shaped.

As shown in Figures 3 and 4-9, the toggle mechanism 12 is installed in the toggle accommodation chamber 11c. The toggle mechanism 12 in this embodiment includes the first elbow flexion arm 8, the second elbow flexion arm 13 and the flexion arm 13. The elbow seat 10, the second end of the first elbow flexion arm 8, the first end and the second end of the second elbow flexion arm 13 are fork-shaped, and the first end of the first elbow flexion arm 8 is located at Between the two yokes of the fork-shaped tail of the extrusion slider 6, and through the first elbow flexion shaft 9 and the two yokes of the fork-shaped tail of the extrusion slider 6 are hinged, the first elbow flexion The second end of the rotating arm 8 is positioned between the two forked arms of the fork-shaped first end of the second elbow-flexing rotating arm 13, and passes through the second elbow-flexing rotating shaft 14 and the forked shape of the second elbow-flexing rotating arm 13. The two yokes at the first end are hinged, and the fork-shaped second end of the second elbow-bending arm 13 is hinged on the elbow-bending seat 10 through the third elbow-bending rotating shaft 15, and the elbow-bending seat 10 is fixed on the moving mold kernel 11. In this way, when the toggle mechanism 12 straightens or bends, it drives the squeeze slider 6 to extend or retract. The toggle mechanism 12 can amplify the force by 20 times or more, so as to overcome the huge injection molding pressure and meet the pressure requirements for injection molding of ultra-thin products. Compared with the commonly used inclined wedge structure, the toggle mechanism has the following advantages: 1. The inclined wedge structure needs a stroke of 60mm to rise 3mm, and the entire extrusion action time of the oil cylinder needs at least 2 seconds. The instantaneous oil flow rate of the hydraulic system is very high. For the injection molding cycle of 4 seconds, the reaction speed is not enough, and the appearance thickness of the final product is not stable; while the elbow structure with the same rising height only needs a stroke of 13mm, and the ordinary hydraulic system can be in place within 0.5 seconds, and the reaction speed is very important for injection molding. Less impact, easier to control. 2. When the force is converted by the oblique wedge at a low angle, the loss ratio of the friction force is very large, and the extrusion force that is truly converted into the vertical direction is insufficient. The elbow-bending structure has less contact area and much less friction, and only one part is required to be rigid enough. 3. The elbow bending structure is close to the vertical. The greater the extrusion force is, the lower the requirements for the oil cylinder, the extrusion is stable. If there is insufficient cylinder force, the elbow bending structure will not move at all, so that it can be clearly seen whether it is in place or not. It is also convenient for production testing.

Preferably, between the end surface of the first end of the first elbow flexion arm 8 and the extrusion slider 6, the end surface of the second end of the first elbow flexion arm 8 and the second elbow Between the end face of the first end of the elbow arm 13 and between the end face of the second end of the second elbow arm 13 and the elbow seat 10, convex and concave arcs are used to cooperate, so that when the elbow mechanism 12 is straightened The rigidity of the entire toggle mechanism 12 is increased by bearing the pressure on the arc surface. Further preferably, the end surface of the first end of the first elbow flexion arm 8 is a first convex circular arc surface 8a, and the tail of the squeeze slider 6 is provided with a first convex circular arc surface 8a. The first concave arc surface 6a of the arc surface 8a matches, and the end face of the second end of the first elbow flexion arm 8 is a second convex arc surface 8b, and the second flex arm The first end of the elbow arm 13 is provided with a concave second inner concave arc surface 13a matching the second outer convex arc surface 8b, and the end surface of the second end of the second elbow arm 13 is It is a third convex arc surface 13b, and the elbow seat 10 is provided with a third concave arc surface 10a matching with the third convex arc surface 13b.

One end of the extruding link 5 is located between the two fork arms of the fork-shaped second end of the first elbow flexion arm 8, and is connected with the second elbow flexion shaft 14, the extruding link The other end of 5 is connected with the telescoping rod of described oil cylinder 1, and oil cylinder 1 is fixed on the oil cylinder holder 2. The oil cylinder 1 is driven to extend or retract, and the toggle mechanism 12 is straightened or bent by extruding the connecting rod 5, thereby realizing the extruding or retracting of the extruding slider 6.

As shown in Figure 10, the extrusion control device 20 includes a controller 21, a hydraulic valve 22, an upstroke switch 3, a stroke switch lever 4 and an indicator light 24, and a delay timer is arranged in the controller 21 to control The signal input end of the device 21 is connected with the injection signal output end of the injection molding machine, and is used to receive the injection signal from the injection molding machine and generate a control signal; the travel switch lever 4 is installed on the extrusion connecting rod 5, and the upper travel switch 3 Installed on one side of the extrusion connecting rod 5, connected with the controller 21, the indicator light 24 is connected with the controller 21; the hydraulic valve 22 is used to control the extension or retraction of the oil cylinder 1, the The group A coil 22 a and group B coil 22 b of the hydraulic valve 22 are respectively connected to the signal output ends of the controller 21 .

In the original state, the controller 21 outputs a control signal to the group A coil 22a of the hydraulic valve 22, the hydraulic valve 22 retreats, and the output oil pressure causes the oil cylinder 1 to retract and drive the elbow flexion mechanism to bend and drive the extrusion slider 6 to retract to empty the mold cavity. Since the wall thickness here is even or a little thicker, the plastic fills in easily. Injection molding steps are as follows:

Step 1, mold clamping;

Step 2, the injection molding machine feeds the glue;

Step 3: Filling the cavity of the mold core, at the same time, the controller 21 receives the injection signal of the injection molding machine, and the controller starts to delay;

Step 4. When the delay time reaches yes, the controller 21 outputs a control signal to the group B coil 22b of the hydraulic valve 22, the hydraulic valve 22 advances, and the output oil pressure is given to the oil cylinder 1 to advance, so that the toggle mechanism 12 is straightened to drive extrusion Slider 6 stretches out, and product is pressed thin; Simultaneously, travel switch lever 4 triggers described mold upper travel switch 3, and described controller 21 turns on described indicator lamp 24, and indicator lamp 24 lights can play prompting effect.

Step 5, the mold core cavity is cooled under pressure;

Step 6: The mold is opened, the controller 21 outputs a control signal to the group A coil 22a of the hydraulic valve 22, the hydraulic valve 22 is reversed, and the oil pressure is output to the oil cylinder to retreat, so that the toggle mechanism 12 bends to drive the extrusion slider 6 to retreat, Squeeze slider 6 to retract;

Step 7. Take out the product.

Continue to the next cycle.

In summary, the injection mold for thin-walled products of the present invention has the following beneficial effects:

(1) The injection mold for thin-walled products uses an in-mold extrusion device at the ultra-thin wall thickness position. The in-mold extrusion device includes an extrusion slider 6, a toggle mechanism 12, an oil cylinder 1, and an extrusion control device 20. The mechanism 12 amplifies the force of the oil cylinder 1 by 20 times or more, thereby overcoming the huge injection molding pressure. When the plastic in the cavity is in a molten state, the extrusion slider 6 starts to extrude to thin the molded product, thereby achieving the thickness of the compressed product in the mold. The injection mold for thin-walled products can be used to produce local thin-walled 1.2mm The following plastic products replace and surpass the high-cost steam high-gloss injection molding production process, which can increase injection molding production efficiency by 40%, reduce single-piece production costs by about 60%, and ensure stable product thickness and stable production.

(2) The extrusion control device 20 of the injection mold for thin-walled products adjusts the start time, duration and exit time of compression through linkage with the injection molding machine tool, and the control accuracy is high.

(3) In addition, the thin-walled product injection mold also has the advantages of simple structure, simple operation, simple molding process, low mold cost and injection molding production cost.

The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims (9)

1. squeezing device in a mould, it is characterized in that, comprise extruding slide block (6), Qu Zhou mechanism (12), oil cylinder (1) and extruding control device (20), described extruding slide block (6) is installed in sliding hole (11a) scalablely, described extruding slide block (6) is connected by the expansion link of Qu Zhou mechanism (12) with described oil cylinder (1), and described extruding control device (20) is for controlling the flexible motion of described oil cylinder (1);Described oil cylinder (1) stretches out or retracts to drive described Qu Zhou mechanism (12) to stretch or bend, thus realizes described extruding slide block (6) and stretch out or retract.

2. squeezing device in mould according to claim 1, it is characterized in that, described Qu Zhou mechanism (12) comprises first and bends elbow pivoted arm (8), 2nd bends elbow pivoted arm (13) and elbow seat in the wrong (10), it is hinged with the afterbody of described extruding slide block (6) that described first first end bending elbow pivoted arm (8) bends elbow rotating shaft (9) by first, it is hinged with the first end of the 2nd elbow pivoted arm (13) in the wrong that first the 2nd end bending elbow pivoted arm (8) bends elbow rotating shaft (14) by the 2nd, it is hinged with elbow seat (10) in the wrong that 2nd the 2nd end bending elbow pivoted arm (13) bends elbow rotating shaft (15) by the 3rd, 2nd bends elbow rotating shaft (14) is connected with the expansion link of described oil cylinder (1).

3. squeezing device in mould according to claim 2, it is characterized in that, described first bend between first end and the afterbody of described extruding slide block (6) of elbow pivoted arm (8), described first bend elbow pivoted arm (8) the 2nd end elbow pivoted arm (13) in the wrong with the described 2nd first end between and adopt convex-concave cambered surface to coordinate between the 2nd end of the described 2nd elbow pivoted arm (13) in the wrong and described elbow seat (10) in the wrong, bear pressure by cambered surface when Shi Qu elbow mechanism (12) stretches.

4. squeezing device in mould according to claim 3, it is characterized in that, the end face of the described first first end bending elbow pivoted arm (8) is outer the first convex outer convex arc surface (8a), the afterbody of described extruding slide block (6) is provided with concaved circular cambered surface (6a) in the first of the indent that convex arc surface (8a) outer with first is mated mutually, the end face of the described first the 2nd end bending elbow pivoted arm (8) is outer the 2nd convex outer convex arc surface (8b), described 2nd first end bending elbow pivoted arm (13) is provided with concaved circular cambered surface (13a) in the 2nd of the indent mated mutually with described 2nd outer convex arc surface (8b) the, the end face of the described 2nd the 2nd end bending elbow pivoted arm (13) is outer the 3rd convex outer convex arc surface (13b), described elbow seat (10) in the wrong is provided with concaved circular cambered surface (10a) in the 3rd of the indent mated mutually with described 3rd outer convex arc surface (13b).

5. squeezing device in mould according to claim 4, it is characterized in that, the first end of the 2nd end and the described 2nd elbow pivoted arm (13) in the wrong that the afterbody, described first of described extruding slide block (6) bends elbow pivoted arm (8) is all in fork-shaped, described first first end bending elbow pivoted arm (8) is positioned between two fork arms of the fork-shaped afterbody of described extruding slide block (6), and the described first the 2nd end bending elbow pivoted arm (8) is positioned between two fork arms of fork-shaped first end that the described 2nd bends elbow pivoted arm (13).

6. squeezing device in mould according to claim 2, it is characterized in that, in described mould, squeezing device also comprises extruding connecting rod (5), one end of described extruding connecting rod (5) is bent elbow rotating shaft (14) with the described 2nd and is connected, and the other end of described extruding connecting rod (5) is connected with the expansion link of described oil cylinder (1).

7. squeezing device in mould according to claim 1, it is characterised in that, described sliding hole (11a) is T-shaped, and described extruding slide block (6) is the T-shaped that hole (11a) sliding with described T-shaped coordinates.

8. squeezing device in mould as claimed in any of claims 1 to 7, it is characterised in that, described extruding control device (20) comprising:

Controller (21), the signal input terminus of controller (21) is connected with the injection signal output terminal of injection moulding machine, for receiving injection signal from injection moulding machine, and produces control signal; With

Hydraulicvalve (22), for controlling, described oil cylinder (1) stretches out or retracts described hydraulicvalve (22), A group coil (22a) and B group coil (22b) of described hydraulicvalve (22) respectively signal output terminal with described controller (21) be connected.

9. squeezing device in mould according to claim 8, it is characterized in that, described extruding control device (20) also comprises mould upper stroke switch (3), travel switch driving lever (4) and pilot lamp (24), described travel switch driving lever (4) is synchronized with the movement with the expansion link of described oil cylinder (1), upper stroke switch (3) is arranged on the side of travel switch driving lever (4), and be connected with described controller (21), pilot lamp (24) is connected with described controller (21).