Mold closing mechanism of injection molding machine

Abstract

The utility model provides a mold closing mechanism of an injection molding machine. The mold closing mechanism solves the problem that each connecting rod of a negative relief angle type mold closing mechanism of an existing injection molding machine is easy to damage. One end of the rear toggle rod is hinged and matched with the supporting plate; one end of the front toggle rod is hinged and matched with the movable template, and the other end is hinged and matched with one end, away from the supporting plate, of the rear toggle rod; the cross joint is mounted at the telescopic end of the telescopic element; and one end of the small connecting rod is hinged and matched with the cross joint, and the other end is hinged and matched with the rear toggle rod. In a mold locking state, the small connecting rod, the rear toggle rod and the front toggle rod are all of an arc-shaped structure, so that deformation is easily caused when the device is stressed; due to the fact that the small connecting rod, the rear toggle rod and the front toggle rod bear part of deformation, the overall deformation of the mold closing mechanism is not concentrated at all hinge points any more and is relatively evenly distributed at the small connecting rod, the rear toggle rod, the front toggle rod and all the hinge points, and therefore fatigue damage caused by stress deformation of connecting pieces due to repeated opening and closing of the whole mold closing mechanism is reduced, and the service life of the mold closing mechanism is prolonged. And the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to injection molding machine technical field, concretely relates to a kind of mold closing mechanisms of injection molding machine. BACKGROUND

[0002] In injection molding process, mold closing mechanism is the key component of injection molding machine, and its performance directly affects the quality of injection molding product, production efficiency, and the running stability and service life of equipment. The main function of mold closing mechanism is to realize the opening and closing action of mold, and to provide sufficient mold closing force during injection molding process to ensure that the mold is tightly closed and prevent plastic melt from overflowing.

[0003] At present, the commonly used inner turning type double-toggle mold closing mechanism of three-plate injection molding machine has one feature that the rear angle in the rear toggle lever is positive, so it is also called positive rear angle mechanism. When facing larger size mold or injection molding process with higher requirement on mold opening and closing stroke, the positive rear angle mechanism often cannot meet the demand, limiting the application range of injection molding machine. For example, in the injection molding production of large plastic products, the positive rear angle mechanism may fail to smoothly complete the opening and closing action of mold due to stroke ratio limitation, causing production stagnation. In terms of force amplification ratio, the positive rear angle mechanism is relatively low, and to achieve the same mold closing force as negative rear angle mechanism, it needs larger driving power. This not only greatly increases the energy consumption of equipment, but also puts higher requirements on the performance of driving device, thereby increasing the cost of equipment. In actual production, for injection molding products that require high mold closing force, the positive rear angle mechanism often cannot provide sufficient mold closing force due to insufficient force amplification ratio, leading to quality problems such as flash and poor dimensional accuracy of products. In terms of mold opening and closing speed and stability, the movement process of positive rear angle mechanism is relatively unstable, and vibration and impact are easy to occur, which not only shortens the service life of mold, but also may cause defects in injection molding products. Moreover, to ensure stability, the positive rear angle mechanism often has to reduce the mold opening and closing speed, thereby reducing the production efficiency. Under the background of increasing demand for current high-speed injection molding production, the disadvantages of positive rear angle mechanism are increasingly prominent.

[0004] To solve the shortcomings of positive rear angle mechanism, Chinese patent authorization announcement No. CN213440965U discloses a negative rear angle type toggle link mold closing mechanism, which has the advantages of short operation and large force amplification ratio. However, due to the increase of force amplification ratio, directly using negative rear angle structure in the same specification mold closing mechanism will lead to the increase of load borne by each link, while the size of link does not change, increasing the risk of fatigue damage or fatigue failure of link. UTILITY MODEL CONTENTS

[0005] To overcome the shortcomings of the background art, the utility model provides a mold closing mechanism of injection molding machine, which solves the problem of easy damage of each link of the existing negative rear angle type mold closing mechanism of injection molding machine.

[0006] The utility model discloses the technical scheme as follows:

[0007] A clamping mechanism of injection molding machine, including support plate, movable die plate and fixed die plate, the support plate is installed with telescopic element, still include:

[0008] The rear elbow lever is hinged to the support plate at one end;

[0009] The front elbow lever is hinged to the movable die plate at one end and to the end of the rear elbow lever away from the support plate at the other end;

[0010] The cross joint is installed on the telescopic end of the telescopic element;

[0011] The small connecting rod is hinged to the cross joint at one end and to the rear elbow lever at the other end.

[0012] The small connecting rod, the rear elbow lever and the front elbow lever are all arc-shaped rods, the rear elbow lever is curved away from the axis of the telescopic element, and the distance from the hinge point of the small connecting rod and the rear elbow lever to the axis of the telescopic element is greater than the distance from the hinge points at the two ends of the rear elbow lever to the axis of the telescopic element.

[0013] The small connecting rod is curved towards one side of the support plate.

[0014] The hinge point of the small connecting rod and the rear elbow lever is close to the hinge point of the rear elbow lever and the front elbow lever.

[0015] The bending direction of the front elbow lever is opposite to that of the rear elbow lever.

[0016] The hinge point of the front elbow lever and the movable die plate is provided with a pin shaft, at least one end of the pin shaft is provided with a first limiting slot, the outside of the movable die plate is provided with a second limiting slot, the movable die plate is provided with a limiting block for cooperating with the first limiting slot and the second limiting slot, and the limiting block is connected with the movable die plate and the pin shaft through bolts.

[0017] The front elbow lever is provided with an oil injection hole close to the pin shaft, and the oil injection hole is provided with a joint.

[0018] The telescopic element is a hydraulic cylinder, and a guide column for cooperating with the movable die plate is arranged between the support plate and the fixed die plate.

[0019] The utility model discloses the beneficial effect is:

[0020] The distance from the hinge joint of the small connecting rod and the rear elbow rod to the axis center line of the telescopic element is greater than the distance from the hinge joints at both ends of the rear elbow rod to the axis center line of the telescopic element, namely the rear angle of the mold closing device is negative; in the mold closing state, since the small connecting rod, the rear elbow rod and the front elbow rod are all arc-shaped structures, deformation is prone to occur when forces are borne; since the small connecting rod, the rear elbow rod and the front elbow rod bear part of the deformation, the overall deformation of the mold closing mechanism is no longer concentrated at the hinge joints, but is relatively uniformly distributed on the small connecting rod, the rear elbow rod, the front elbow rod and the hinge joints, thus reducing the fatigue damage of the connecting piece caused by the overall deformation of the mold closing mechanism due to repeated opening and closing, and prolonging the service life. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic view of the mold closing state of the utility model.

[0022] Figure 2 is a schematic view of the mold opening state of the utility model.

[0023] Figure 3 is a schematic view of the cooperation of the movable die plate and the pin shaft of the utility model.

[0024] Figure 4 is a schematic view of the lubricating structure of the front elbow rod of the utility model.

[0025] Support plate 1, movable die plate 2, fixed die plate 3, telescopic element 4, rear elbow rod 5, front elbow rod 6, cross joint 7, small connecting rod 8, pin shaft 9, No. 1 limiting groove 10, No. 2 limiting groove 11, limiting block 12, oil injection hole 13, joint 14, guide column 15. DETAILED DESCRIPTION

[0026] The utility model will be further described below in combination with the drawings and embodiments:

[0027] In the embodiment, as shown in Figure 1 , Figure 2 A mold closing mechanism of an injection molding machine, comprising a support plate 1, a movable die plate 2 and a fixed die plate 3, the support plate 1 is installed with a telescopic element 4, further comprising:

[0028] Rear elbow rod 5, one end is hingedly matched with the support plate 1;

[0029] Front elbow rod 6, one end is hingedly matched with the movable die plate 2, and the other end is hingedly matched with the end of the rear elbow rod 5 away from the support plate 1;

[0030] Cross joint 7, installed on the telescopic end of the telescopic element 4;

[0031] Small connecting rod 8, one end is hingedly matched with the cross joint 7, and the other end is hingedly matched with the rear elbow rod 5;

[0032] The small connecting rod 8, the rear elbow rod 5 and the front elbow rod 6 are all arc-shaped rods, the rear elbow rod 5 is bent towards the direction away from the axis line of the telescopic element 4, and the distance from the hinge joint of the small connecting rod 8 and the rear elbow rod 5 to the axis line of the telescopic element 4 is greater than the distance from the hinge joints at both ends of the rear elbow rod 5 to the axis line of the telescopic element 4.

[0033] The distance from the hinge joint of the small connecting rod 8 and the rear elbow rod 5 to the axis line of the telescopic element 4 is greater than the distance from the hinge joints at both ends of the rear elbow rod 5 to the axis line of the telescopic element 4, that is, the rear angle of the mold closing device is negative; in the mold closing state, since the small connecting rod 8, the rear elbow rod 5 and the front elbow rod 6 are all arc-shaped structures, they are easy to deform under force; since the small connecting rod 8, the rear elbow rod 5 and the front elbow rod 6 bear part of the deformation, the overall deformation of the mold closing mechanism is no longer concentrated at the hinge joints, but is relatively evenly distributed at the small connecting rod, the rear elbow rod, the front elbow rod and the hinge joints, thus reducing the fatigue damage of the connecting members caused by the stress deformation due to repeated opening and closing of the mold closing mechanism, and prolonging the service life thereof.

[0034] In the embodiment, as shown in Figure 1 , Figure 2 , the small connecting rod 8 is bent towards one side of the support plate 1. Compared with the connecting rod without an arc, the small connecting rod 8 bent towards one side of the support plate 1 is less likely to interfere with the front elbow rod 6.

[0035] In the embodiment, as shown in Figure 1 , Figure 2 , the hinge joint of the small connecting rod 8 and the rear elbow rod 5 is close to the hinge joint of the rear elbow rod 5 and the front elbow rod 6. Since the small connecting rod 8 is bent towards one side of the support plate 1, the small connecting rod 8 and the rear elbow rod 5 can be closer to the hinge joint of the rear elbow rod 5 and the front elbow rod 6, so that the mold closing stroke is greater, the mold opening distance is longer, the mold plate is stressed evenly and deformed less, thereby prolonging the service life of the mold and the machine, maintaining the product weight repeat accuracy, and effectively reducing the flash phenomenon.

[0036] In the embodiment, as shown in Figure 1 , Figure 2 , the bending directions of the front elbow rod 6 and the rear elbow rod 5 are opposite. When the front elbow rod 6 and the rear elbow rod 5 rotate relative to each other, they are less likely to interfere with each other, ensuring smooth rotation of the rear elbow rod 5.

[0037] In the embodiment, as shown in Figure 1 , Figure 2 , Figure 3As shown, a pin 9 is provided at the hinge joint between the front elbow 6 and the moving template 2. At least one end of the pin 9 has a first limiting groove 10, and the outer side of the moving template 2 has a second limiting groove 11. The moving template has a limiting block 12 for engaging with the first limiting groove 10 and the second limiting groove 11. The limiting block 12 is connected to the moving template 2 and the pin 9 respectively by bolts. Similarly, the hinge structures of the rear elbow 5 and the small connecting rod 8 are the same as those between the front elbow 6 and the moving template 2. The pin 9 can be fixed to the moving template 2 and simultaneously limited by bolts, resulting in a simple structure that is easy to assemble and disassemble.

[0038] In the embodiments, such as Figure 4 As shown, the front elbow 6 has an oil injection hole 13 near the pin 9, and a connector 14 is provided at the oil injection hole 13. Lubricating oil is introduced to lubricate the hinge of the front elbow 6, facilitating the rotation of the front elbow 6.

[0039] In the embodiments, such as Figure 1 , Figure 2 As shown, the telescopic element 4 is a hydraulic cylinder, and a guide post 15 is provided between the support plate 1 and the fixed template 3 for cooperating with the moving template 2. This ensures the smooth movement and straightness of the moving template 2, thereby ensuring the accuracy of the fit between the moving template 2 and the fixed template 3.

[0040] Obviously, the above embodiments of this utility model are merely illustrative examples and not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, these obvious variations or modifications derived from the essential spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A clamping mechanism of an injection molding machine, comprising a support plate (1), a movable mold plate (2) and a fixed mold plate (3), said support plate (1) being provided with a telescopic element (4), characterized in that, Also include: The rear elbow bar (5) is hingedly connected to the support plate (1); The front elbow bar (6) is hingedly connected to the movable die plate (2) at one end and to the other end of the rear elbow bar (5) away from the support plate (1); The cross joint (7) is installed on the telescopic end of the telescopic element (4); The small connecting rod (8) is hingedly connected to the cross joint (7) at one end and to the rear elbow bar (5) at the other end; The small connecting rod (8), the rear elbow bar (5) and the front elbow bar (6) are all arc-shaped rods, the rear elbow bar (5) is curved away from the axis of the telescopic element (4), and the distance from the hinge point of the small connecting rod (8) and the rear elbow bar (5) to the axis of the telescopic element (4) is greater than the distance from the hinge points of the two ends of the rear elbow bar (5) to the axis of the telescopic element (4).

2. A clamp mechanism for an injection molding machine as defined in claim 1, wherein: The small connecting rod (8) is curved towards one side of the support plate (1).

3. A clamp mechanism for an injection molding machine as defined in claim 1 wherein: The hinge point of the small connecting rod (8) and the rear elbow bar (5) is close to the hinge point of the rear elbow bar (5) and the front elbow bar (6).

4. A clamp mechanism for an injection molding machine as defined in claim 1 wherein: The bending direction of the front elbow bar (6) is opposite to that of the rear elbow bar (5).

5. A clamp mechanism for an injection molding machine as defined in claim 3 wherein: The hinge point of the front elbow bar (6) and the movable die plate (2) is provided with a pin shaft (9), at least one end of the pin shaft (9) is provided with a first limiting groove (10), the outer side of the movable die plate (2) is provided with a second limiting groove (11), the movable die plate is provided with a limiting block (12) for cooperating with the first limiting groove (10) and the second limiting groove (11), and the limiting block (12) is connected with the movable die plate (2) and the pin shaft (9) by bolts respectively.

6. A clamp mechanism for an injection molding machine as defined in claim 5 wherein: The front elbow bar (6) is provided with an oil injection hole (13) near the pin shaft (9), and the oil injection hole (13) is provided with a connector (14).

7. A clamp mechanism for an injection molding machine as defined in claim 1 wherein: The telescopic element (4) is a hydraulic cylinder, and a guide column (15) for cooperating with the movable die plate (2) is arranged between the support plate (1) and the fixed die plate (3).

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