KR20200070203A - Clamping apparatus of toggle type for injection molding machine - Google Patents

Abstract

The present invention discloses a toggle type clamping apparatus of an injection molding machine, which includes: a fixed template on which a fixed mold is mounted; a movable template forwardly and backwardly installed with respect to the fixed template and mounted thereon with a movable mold corresponding to the fixed mold; a toggle mechanism positioned between the movable template and a toggle support spaced apart from a rear of the movable template to move the movable template, and having a cross-head moved while being coupled to a drive shaft operated by a clamping motor, and a link assembly coupled to the cross-head and connecting the toggle support and the movable template to each other; and a hydraulic cylinder installed at a rear of the cross-head to support the cross-head to prevent a toggle folding phenomenon.

Description

{CLAMPING APPARATUS OF TOGGLE TYPE FOR INJECTION MOLDING MACHINE}

The present invention relates to an injection molding machine, and more particularly, to a toggle mold clamping apparatus of an injection molding machine having a means for maintaining a mold opening state in an injection compression mode.

The injection molding machine molds a molded product by injecting molten resin from an injection apparatus, filling the cavity of the mold apparatus, and solidifying it. The mold device is composed of a fixed mold and a movable mold. Mold closing, mold clamping, and mold opening of the mold apparatus are performed by a mold clamping apparatus. The clamping device includes a movable plate and a stationary plate and a driving source such as a motor for moving the movable plate and a toggle mechanism.

The general injection mode of the injection molding machine is as follows. First, the movable mold plate of the mold clamping device in the mold open state is moved at a high speed in the direction of the fixed mold plate. When the movable mold installed on the movable mold plate comes into contact with the fixed mold installed on the fixed mold plate according to the movement of the movable mold plate, the pressure is increased to form a clamp force. Then, the nozzle of the injection device is advanced into a mold to cool the resin after injection. Thereafter, the movable mold plate of the mold clamping device is retracted to separate the movable mold and the fixed mold, and finally, the movable mold plate is retracted at a high speed to take out the injection molded product.

In this general injection mode, in the mold closing and clamping process, the gap between the movable mold and the fixed mold is not maintained, and the movable mold and the fixed mold are kept in close contact, and then the resin is injected. Therefore, a large clamping force is required for a long time. In order to solve this problem, in the mold closing process, after maintaining a constant gap without directly adhering the movable mold and the fixed mold, after a certain amount of resin is filled in the cavity space in the mold, the injection compression mode in which the movable mold and the fixed mold are in close contact Is being used.

In this way, when the movable mold and the fixed mold are not brought into close contact in the mold closing process and a constant gap is maintained, only a small clamp force is required than when the movable mold and the fixed mold are brought into close contact. For example, if a gap of 0.1 mm or less is maintained between the movable mold and the fixed mold, a clamping force of about 95% of the clamping force is required when the movable mold and the fixed mold are in close contact. In addition, if a gap of 0.5 mm is maintained between the movable mold and the fixed mold, a clamping force of about 70% of the clamping force is required when the movable mold and the fixed mold are in close contact.

However, in the mold closing process, when the resin is injected while maintaining a constant gap without directly adhering the movable mold and the fixed mold, the phenomenon that the movable mold plate is pushed back may occur due to the injection pressure of the resin. That is, the state in which a constant gap between the molds is not directly brought into close contact with the movable molds and the fixed molds is that the toggle link of the toggle-type clamping device is not fully opened, so that the movable mold plate is driven by the pressure of the resin filled in the cavity in the mold. The phenomenon of being pushed back occurs. Accordingly, there is also a phenomenon in which an accurate injection product is not molded or the movable mold plate does not advance in the direction of a fixed mold, so that there is no contact between molds. In addition to this, the state in which the toggle is not fully unfolded (folding phenomenon) continuously occurs.

The present invention has been devised in consideration of the above problems, and its object is to provide a toggle-type clamping device for an injection molding machine whose structure is improved such that the movable mold plate is not pushed backward when the injection compression mode is driven and the toggle link operates normally. .

Another object of the present invention is to provide a toggle-type clamping device for an injection molding machine capable of performing injection compression of various thicknesses by preventing the movable plate from being pushed back when the injection compression mode is driven.

One aspect of the present invention for achieving the above object, a fixed mold plate is mounted fixed mold; A movable mold plate installed to be movable forward and backward with respect to the fixed mold plate and mounted with a movable mold corresponding to the fixed mold; It is located between the toggle support spaced apart from the rear of the movable platen and the movable platen to move the movable platen, and is coupled to a crosshead and a crosshead moving coupled to a drive shaft operated by a molded motor. A toggle mechanism having a link assembly connecting the toggle support and the movable plate to each other; And a first hydraulic cylinder disposed side by side with the drive shaft so as to be symmetrical on the upper, lower, left, and right sides of the driving shaft, and positioned between the toggle support and the crosshead to support the crosshead from the rear of the crosshead. And a second hydraulic cylinder; When the gap between the movable mold and the fixed mold reaches a set gap during the mold closing operation, the rods of the first hydraulic cylinder and the second hydraulic cylinder advance to support the crosshead, and the first hydraulic pressure during mold opening operation Provided is a toggle-type clamping device for an injection molding machine characterized in that the rod of the cylinder and the second hydraulic cylinder is retracted to release support for the crosshead.

The first hydraulic cylinder and the second hydraulic cylinder are single rod hydraulic cylinders, and rod ends of the first hydraulic cylinder and the second hydraulic cylinder are respectively connected to the crosshead through a joint, and the joints of the first hydraulic cylinder are The joint of the second hydraulic cylinder is based on the crosshead It is characterized by being arranged to face in the vertical direction.

The link assembly is characterized in that it has a short link and a long link coupled through the joint to connect the toggle support and the movable plate to each other, and a cross head link coupling the cross head and the short link. .

The link assembly is characterized in that a pair of symmetry is arranged on both sides around the crosshead.

Another aspect of the present invention for achieving the above object is a fixed mold plate is mounted fixed mold; A movable mold plate installed to be movable forward and backward with respect to the fixed mold plate and mounted with a movable mold corresponding to the fixed mold; A crosshead positioned between the toggle support spaced apart from the rear of the movable mold plate and the movable mold plate to move the movable mold plate and coupled to a drive shaft operated by a mold motor; A short link and a long link coupled through a joint to connect the toggle support and the movable plate to each other, and a cross head link coupling the cross head and the short link, are provided on both sides of the cross head. A pair of link assemblies arranged symmetrically; And a two rod hydraulic cylinder having a rod end coupled to the long link provided in the pair of link assemblies, respectively; When the gap between the movable mold and the fixed mold reaches a set gap during the mold closing operation, the rods of the two rod hydraulic cylinders advance to support the pair of link assemblies in a direction that is apart from each other, and when the mold opening operation is performed, the both rods Provided is a toggle-type clamping device for an injection molding machine characterized in that the rod of the hydraulic cylinder is retracted to release support for the pair of link assemblies.

According to the present invention, when the injection molding mode is driven in the injection molding machine, when the movable mold and the fixed mold maintain a constant gap, the hydraulic cylinder is used to support the crosshead or link assembly to maintain the gap, so that the movable mold plate is normally pushed without being pushed back. The link will work.

In addition, when the injection compression mode is driven, the movable platen can be prevented from being pushed back to perform injection compression of various thicknesses, and it is possible to minimize mechanism changes, thereby improving the function of the mold clamping device at low cost.

Therefore, when the present invention is applied, the clamping force of the toggle mechanism can be reduced by maintaining a constant gap between the movable mold and the fixed mold in the injection compression mode, and accordingly, the machine life of the injection molding machine can be extended.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described below, and thus the present invention is described in such drawings. It is not limited to interpretation.
1 is a view showing the configuration of a toggle-type mold apparatus of an injection molding machine according to a preferred embodiment of the present invention.
FIG. 2 is a view showing the configuration of a single rod hydraulic cylinder in FIG. 1.
3 is a view showing the configuration of a toggle-type clamping device of an injection molding machine according to another embodiment of the present invention.
4 is a view showing the configuration of the two-load hydraulic cylinder in FIG.
5 is a flowchart showing the operation process of the toggle-type clamping device of the injection molding machine according to a preferred embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms or words used in the present specification and claims should not be interpreted as being limited to ordinary or dictionary meanings, and the inventor appropriately explains the concept of terms in order to explain his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention. Therefore, the configuration shown in the embodiments and drawings described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, and thus can replace them at the time of application. It should be understood that there may be equivalents and variations.

1 is a view showing the configuration of a toggle-type mold apparatus of an injection molding machine according to a preferred embodiment of the present invention.

Referring to FIG. 1, the toggle-type clamping device of the injection molding machine according to the preferred embodiment of the present invention includes a fixed mold plate 100 on which a fixed mold 11 is mounted, and a movable mold 12 corresponding to the fixed mold 11 The movable platen 101 mounted thereon, a toggle mechanism 110 positioned between the toggle support 120 and the movable platen 101 to move the movable platen 101, and a mold opening maintenance function when the injection compression mode is driven The first hydraulic cylinder 140 and the second hydraulic cylinder 150 are provided.

The fixed plate 100 is fixed to the frame 103 as a fixed mold support device, and a movable plate 101 is installed behind the fixed plate 100 so as to be able to move forward and backward. In addition, a toggle support 120 is spaced apart from the rear of the movable plate 101, and the tie bar supports the clamping force between the fixed plate 100 and the movable plate 101 and guides the movement of the movable plate 101 ( Tie-Bar) 102 is provided.

The movable plate 101 is installed to face the fixed plate 100 and is a movable mold support device installed to move forward and backward along the tie bar 102, moved by the operation of the toggle mechanism 110, to mold closing, A mold and mold opening operation is performed. Here,'mold' means that the movable mold plate 101 is retracted to separate the movable mold 12 from the fixed mold 11. In addition, the term'mold' is in a state from the state where the movable mold 12 is spaced apart from the fixed mold 11 until the parting surface of the movable mold 12 contacts the parting surface of the fixed mold 11. , It means that the movable mold 12 is approached to the fixed mold 11. In this state, the first clamping force is set as the clamping force. When the mold motor 130, which is a driving unit, drives and pushes the crosshead 111, the link assembly 112 of the toggle mechanism 110 is unfolded and the mold closing is performed. The'mold' means that the stationary mold 11 is in contact with the movable mold 12 by applying more force to the movable mold 12. In this state, a second clamping force larger than the above-described first clamping force is set as the clamping force, and the clamping operation is performed at a speed lower than the speed at the time of closing.

The mold member 10, which is a portion where resin is injected, is composed of a fixed mold 11 and a movable mold 12. The fixed mold 11 is mounted on the mold mounting surface opposite to the movable mold plate 101 in the fixed mold plate 100, and the movable mold 12 is molded to face the fixed mold plate 100 in the movable mold plate 101 It is mounted on the mounting surface.

A toggle mechanism 110 is provided between the movable plate 101 and the toggle support 120. In addition, the rear end of the toggle support 120 is provided with a mold motor 130 as a driving source for the mold to operate the toggle mechanism 110. The mold motor 130 provides a driving force to the toggle mechanism 110 by operating the drive shaft 132 via a predetermined power conversion mechanism 131. Here, a ball screw shaft may be preferably employed as the drive shaft 132. Here, the mold motor 130 is preferably a servo motor, and is provided with a mold opening/closing position sensor (not shown) as an encoder for detecting the number of revolutions.

The toggle mechanism 110 receives the power generated by the mold motor 130 and moves the movable mold plate 101 forward and backward. To this end, the toggle mechanism 110 is coupled to the moving cross head 111 coupled to the drive shaft 132, the cross head 111, and the toggle support 120 and the movable plate 101 And link assemblies 112 that connect to each other.

The crosshead 111 is coupled to the driving shaft 132 and moves forward and backward in association with the movement of the driving shaft 132. That is, when the crosshead 111 is advanced (moved in the right direction in FIG. 1), the movable mold plate 101, which is the driven part, is advanced via the link assembly 112 to perform mold closing. At this time, the clamping force generated by multiplying the thrust force by the clamping motor 130 by the toggle magnification is generated, and the clamping is performed by the clamping force.

The link assembly 112 couples the short link 112a and the long link 112b connecting the toggle support 120 and the movable plate 101 to each other, and the cross head 111 and the short link 112a through a joint. The ring has a crosshead link 112c. Here, the short link 112a and the long link 112b may be coupled in series with each other through a joint. The link assembly 112 is preferably a pair of symmetrically arranged on both sides of the upper and lower (or left, right) centered around the crosshead 111.

The first hydraulic cylinder 140 and the second hydraulic cylinder 150 support the crosshead 111 from the rear of the crosshead 111 to prevent the toggle link from being folded when the injection compression mode is driven. Preferably, the first hydraulic cylinder 140 and the second hydraulic cylinder 150 are located between the toggle support 120 and the crosshead 111. Here, as the first hydraulic cylinder 140 and the second hydraulic cylinder 150, a single rod hydraulic cylinder is employed, in which case the rear end of the body is supported by the toggle support 120 and the ends of each rod 141,151 are joints ( By being substantially connected to the crosshead 111 through A, B), the crosshead 111 is supported against the toggle support 120 to prevent the crosshead 111 from being pushed back.

The first hydraulic cylinder 140 and the second hydraulic cylinder 150 are symmetrically arranged around the drive shaft 132. That is, the first hydraulic cylinder 140 and the second hydraulic cylinder 150 are It is arranged on the upper, lower or left and right sides of the drive shaft 132. In addition, the hydraulic cylinder 140 is preferably disposed in parallel with the drive shaft 132 so as to apply a support force opposite to the direction in which the crosshead 111 is pushed. Here, the joint (A) of the first hydraulic cylinder 140 and the joint (B) of the second hydraulic cylinder 150 are disposed to face in the vertical direction relative to the crosshead 111.

As shown in Figure 2, the first hydraulic cylinder 140 and the second hydraulic cylinder 150 by the operation of the hydraulic valve a, the movement path for the oil (1) supplied as a working fluid to the cylinder head (142,152) By opening and closing the rod (141,151) can selectively provide a function for supporting the crosshead (111). The first hydraulic cylinder 140 and the second hydraulic cylinder 150 As a single rod hydraulic cylinder to be implemented, a conventional product can be adopted, so detailed description thereof will be omitted.

3 shows the configuration of the toggle-type clamping device of the injection molding machine according to another embodiment of the present invention. In this embodiment, the hydraulic cylinder 160 supports a pair of link assemblies 112 symmetrically arranged on both sides around the crosshead 111 in both directions , that is, a direction in which a pair of link assemblies are opened. Here, a pair of link assemblies 112 may be disposed on the upper, lower, left, or right sides of the crosshead 111.

As the hydraulic cylinder 160, the ends of the both rods 161 and 162 are double-loaded hydraulic cylinders substantially coupled to the long links 112b provided in the pair of link assemblies 112 through joints C and D, respectively. It is preferred that is employed. Since the hydraulic cylinder 160 acts to support a pair of link assemblies 112 in the direction in which they are opened, the joints C and D to which the both rods 161 and 162 of the hydraulic cylinder 160 are respectively connected face up and down. It is preferably arranged. In addition, in order to efficiently support a pair of link assemblies 112 when the hydraulic cylinder 160 is operated, it is preferable that the joints C and D to which the both rods 161 and 162 are respectively connected are connected to the long link 112b. Do. That is, when the hydraulic cylinder 160 is operated, toward the retraction direction of the long link 112b Both rods 161 and 162 advance up and down, respectively, to apply a support force to the long link 112b. As described above, it is possible to prevent the bonding of the link assembly 112 by providing a pressing force to the front end of the bending of the toggle link.

As shown in Figure 4, the hydraulic cylinder 160 is operated by the hydraulic valve a, so that the movement paths for the oil 1 supplied as the working fluid to the cylinder head 163 are opened and closed, so that both ends of the rods 161 and 162 Each may selectively provide a function of supporting the long link 112b of the link assembly 112. As a double rod hydraulic cylinder that implements the hydraulic cylinder 160, a conventional product can be adopted, so a detailed description thereof will be omitted.

5 is a flowchart showing an operation process for a toggle-type clamping device of an injection molding machine according to a preferred embodiment of the present invention.

Referring to FIG. 5, first, the injection molding machine receives and sets the gap information between the fixed mold 11 and the movable mold 12 in the injection compression mode through a predetermined control device included therein (S100). Here, the gap is a value between 0.1 mm and 0.5 mm, for example.

Next, the injection molding machine drives the mold motor 130 to perform a mold closing operation for moving the movable mold plate 101 in the direction of the fixed mold plate 100 (S110). That is, the mold motor 130 pushes the crosshead 111 and accordingly the mold assembly is performed while the link assembly 112 of the toggle mechanism 110 is unfolded.

The injection molding machine checks the gap between the movable mold 12 and the fixed mold 11 while moving the movable mold plate 101 in the direction of the fixed mold plate 100 and checks whether the gap reaches the gap set in step S100 above ( S120). That is, it is confirmed whether the positions of the movable mold 12 and the fixed mold 11 reach the position of the gap. When the gap between the movable mold 12 and the fixed mold 11 reaches the gap set in step S100, the injection molding machine operates the hydraulic cylinders 140, 150, 160 to provide support force. That is, in the case of the toggle-type clamping device shown in FIG. 1, the hydraulic valve a is operated by the control device to simultaneously load the rod 141 of the first hydraulic cylinder 140 and the rod 151 of the second hydraulic cylinder 150 at the same time. By advancing, the crosshead 111 is supported in the pushing direction. In addition, in the case of the toggle-type clamping device shown in FIG. 3, the hydraulic valve a is operated by the control device so that both rods 161 and 162 of the hydraulic cylinder 160 are simultaneously advanced to support a pair of link assemblies 112 in the direction of opening. It is provided (step S130). Thus, the folding phenomenon of the toggle link is prevented and the movable plate 101 is prevented from being pushed back by the injection pressure of the resin.

Subsequently, the injection molding machine injects molten resin into the cavities in the molds 11 and 12 (S140). When the cavity is filled with a molten resin by a preset threshold, the injection molding machine drives the mold motor 130 to move the movable plate 101 in the direction of the fixed plate 100 to move the mold 12 and the fixed mold 11 ) In close contact (S160). That is, in a state in which a constant gap between the movable mold 12 and the fixed mold 11 is maintained, when the molten resin is filled in a predetermined amount in the molds 11 and 12, the toggle-type mold clamping device performs a mold clamping operation.

In the state where the movable mold 12 and the fixed mold 11 are in close contact, the injection molding machine completes the injection process by completing filling of the molten resin in the remaining spaces of the cavities in the molds 11 and 12 (S170).

Subsequently, the injection molding machine releases the supporting force by operating the hydraulic cylinders 140, 150, and 160 (S180). That is, in the case of the toggle-type clamping device shown in FIG. 1, the hydraulic valve a is operated by the control device to simultaneously load the rod 141 of the first hydraulic cylinder 140 and the rod 151 of the second hydraulic cylinder 150 at the same time. By retreating, the support force applied to the crosshead 111 is released. In addition, in the case of the toggle-type clamping device shown in FIG. 3, the hydraulic valve a is operated by the control device so that both rods 161 and 162 of the hydraulic cylinder 160 retract at the same time, thereby supporting the force applied to the pair of link assemblies 112. Release.

In addition to releasing the support force as above, When the crosshead 111 is pulled back by driving the molded motor 130 which is a driving unit, the linking assembly 112 of the toggle mechanism 110 is folded and a mold opening operation is performed (S190).

As described above, the toggle-type clamping device of the injection molding machine according to the present invention uses the hydraulic cylinders 140, 150, and 160 when the movable mold 12 and the fixed mold 11 maintain a constant gap when driving the injection compression mode. ) Or by maintaining the gap by supporting the link assembly 112 so that the resin injection can be normally performed without the movable plate 101 being pushed back.

Although the present invention has been described above by way of limited examples and drawings, the present invention is not limited by this and will be described below and the technical idea of the present invention by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the equal scope of the claims.

11: fixed mold 12: movable mold
100: fixed plate 101: movable plate
102: tie bar 103: frame
110: toggle mechanism 111: crosshead
112: link assembly 112a: short link
112b: long link 112c: crosshead link
120: toggle support 130: shape motor
131: power switching mechanism 132: drive shaft
140: first hydraulic cylinder 150: second hydraulic cylinder
160: hydraulic cylinder A, B, C, D: joint

Claims (1)

A fixed plate on which a fixed mold is mounted;
A movable mold plate installed to be movable forward and backward with respect to the fixed mold plate and mounted with a movable mold corresponding to the fixed mold;
A crosshead positioned between the toggle support spaced apart from the rear of the movable mold plate and the movable mold plate to move the movable mold plate and coupled to a drive shaft operated by a mold motor;
A short link and a long link coupled through a joint to connect the toggle support and the movable plate to each other, and a cross head link coupling the cross head and the short link, are provided on both sides of the cross head. A pair of link assemblies arranged symmetrically; And
A double rod hydraulic cylinder having an end of the rod coupled to the long link provided in the pair of link assemblies, respectively;
When the gap between the movable mold and the fixed mold reaches a set gap during the mold closing operation, the rods of the two rod hydraulic cylinders are advanced to support the pair of link assemblies in a direction apart from each other,
A toggle type clamping device for an injection molding machine characterized in that the rod of the both rod hydraulic cylinder is retracted during mold opening operation to release support for the pair of link assemblies.

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