KR100873335B1 - Clamping unit for the plastic injection molding machine - Google Patents

Abstract

A mold clamping unit of an injection molding machine is provided to improve the productivity of the injection molding machine by reducing the time for generating the clamping force and cut down on the production cost by maintaining the clamping force using a pair of center half nuts arranged to surround a center column. A mold clamping unit of an injection molding machine comprises first and second fixed plates(1a,1b) in which both ends of tie bars(2) are supported, a fixed mold(3a) attached to the first fixed plate, a movable plate(5) which is installed on the tie bars, a movable mold(3b) which is installed to face the fixed mold, an intensifying cylinder(4) formed in the second fixed plate, an intensifying ram(41) which is mounted on the intensifying cylinder to be movable, a center column(6) which is protruded to pass through the center of the intensifying cylinder and intensifying ram and has a thread(61) formed by alternated ring projection and ring groove on an end, a plurality of clamping cylinders(7), a half nut fixing plate(82) which is fixed to the free surface of the intensifying ram, a pair of center half nuts(8) which is formed in order to tighten or loosen the thread of the center column, and a column guide(9) surrounding the center column.

Description

Clamping unit for the plastic injection molding machine

1 is a cross-sectional plan view showing an installation state of a clamping device of an injection molding machine for explaining the present invention.

2 to 5 is a view showing an operating state of the mold clamping apparatus of the present invention,

   2 is a state in which the moving mold is moved to the fixed mold and the mold operation,

   3 is an operating state in which the center half nut of the clamping device restrains the center column.

   4 is an operating state when the boosting ram of the clamping device maintains the clamping force,

   5 is an operating state when the boosting ram of the clamping device releases the clamping force.

FIG. 6 is an installation state diagram of the clamping device shown in sectional view taken along the line A-A in FIG. 1; FIG.

7 and 8 is a center half nut operating state of the mold clamping apparatus of the present invention.

※ Explanation of code for main part of drawing

1a, 1b: 1st and 2nd fixed mold plate 2: tie bar

3a: fixed mold 3b: movable mold

4: boosting cylinder 41: boosting ram

42,43: first and second chambers 44: hollow part

5: moving plate 6: center column

61: uneven portion 7: shape transfer cylinder

8: A pair of center half nuts 8a, 8b: Both side half nuts

81: fixing pin 82: half nut fixing plate

83: cylinder for half nut operation 84: piston rod

85: Round trip port 86,87: Both side link

88: guide plate 9: column guide

91: bushing 92: guide support bar

The present invention relates to a molding apparatus of an injection molding machine, and more particularly, by pressing the central portion of the moving mold to closely contact the mobile mold to the fixed mold in a state in which the moving mold of the injection molding machine is moved to a fixed mold. A plurality of ring protrusions are formed on the boosting ram of the booster cylinder which closes the movable mold to the fixed mold, and the clamping force is not restrained from the fixed mold by restraining the closed mold by restraining the ring protrusion of the booster ram. It relates to a clamping device for generating a.

In general, the mold clamping apparatus of an injection molding machine is divided into a toggle type and a direct type.

The former toggle clamping device uses the expansion ratio of the toggle link as the mechanical principle of the mechanical link mechanism, so that a large clamping force can be generated by a small clamping cylinder. Although energy consumption can be reduced, it is pointed out that a separate mold adjusting device is required for mold adjusting when the mold is replaced, and that mold adjusting takes a long time.

The latter direct pressure clamping device has a structure that generates the clamping force and the clamping force in the same cylinder, so a large cylinder is required. As a result, a large amount of hydraulic oil is required, and thus energy consumption for maintaining the force required for the clamping force is required. It has been pointed out that a lot of time and mold opening and closing time takes a lot.

And as a device other than the toggle type and direct pressure clamping device described above, the fastening / clamping system proposed in Korean Patent No. 0314356 has a plurality of fixed protrusions (formerly referred to as 'multiple') formed at the end of the column protruding from the rear side of the movable platen. The teeth are formed in the axial direction, and grooves (linear grooves) are formed in the axial direction, and the movable protrusions formed in the inner circumferential surface of the fixing nut which surrounds the fixing protrusions of the column (the publication describes a plurality of teeth). Is engaged to the column-side fixing projections, the clamping force is maintained, while the movable projection is released from the fixing projections and is located in the groove, and the clamping force is lost. In order to operate the fixing nut in rotation, a link device and a separate operation device (for example, a cylinder device) for operating the link device must be provided. As a result, the structure is complicated and the number of assembly parts is increased, which increases the production cost of the injection molding machine. Above all, the operating device that repeatedly reciprocates the fixed nut at an angle is within the tolerance range according to the injection molding speed. In the case of repeated reciprocating operation, accumulation of the tolerance may cause the movable nut of the fixing nut not to engage with the fixing protrusion of the column, or the movable protrusion may not come out of the fixing protrusion completely. In this case, the injection molding machine will fail.

In addition, Patent No. 0719223 proposed by the applicant of the present invention has a half nut installed in each of the four tie bars (guiding tie bars) for guiding the movement of the moving mold mounted with the moving mold part of the injection molding machine to each tie bar described above. It is configured to maintain the clamping force by restraining the formed convex and concave portion, which is required to install a total of four half-nuts, each one of the four corners of the movable plate that is installed so that a total of four tie bars penetrate the injection molding machine Increasing assembly time and manpower is required, and the production cost of the injection molding machine becomes expensive because the expensive half nuts need to be installed four by one.

The present invention has been made in view of the above-mentioned matters in the prior art, and a mold is rapidly formed by using a moving mold installed as a mold transfer cylinder to enable a reciprocating movement to a tie bar in order to mold and mold a movable mold with respect to a fixed mold. In the state where the movable mold is fixed to the stationary mold, the center half nut is engaged with a plurality of ring protrusions formed at the end of the center column, and then the boosting pressure of the boosting ram is increased during the boosting operation of the boosting cylinder. By acting on the center column through the center half nut, the time required to maintain the clamping force in the state where the moving mold and the fixed mold are closed can be achieved within a short time that a small amount of hydraulic pressure is supplied to the pressure-increasing cylinder. The clamping force maintenance operation can be performed quickly, The purpose of this invention is to provide a clamping device to improve acidity, while improving the productivity of the injection molding machine as well as maintaining the clamping force as a structure that restrains the center column using only one expensive center half nut. It was invented for a different purpose to reduce the production cost of the injection molding machine.

The present invention as a means for achieving the above object,

First and second fixed mold plates on which both ends of the tie bars are supported, fixed molds detachably mounted to the first fixed mold plates, movable mold plates movably installed on the plurality of tie bars, and the movable mold plate. A movable mold detachably installed to face the fixed mold on the front surface, a boosting cylinder formed on the second fixed mold plate, a boosting ram movably mounted on the boosting cylinder, and attached to a rear surface of the movable mold plate. In the injection molding machine having a center column protruding to penetrate the center of the boosting ram and the boosting cylinder, and a plurality of mold transfer cylinders for reciprocating the movable die back and forth,

An uneven portion in which a plurality of ring protrusions and ring grooves are alternately continuously formed at an end of the center column reciprocating the hollow portion formed at the center of the boost ram;

A half nut fixing plate fixedly attached to a free surface of the boosting ram exposed to protrude to one side from the boosting cylinder;

A cross section is formed in a semicircular shape so as to cover half of the center column, and a plurality of convex parts and concave parts are formed on an inner circumferential surface of the center column, and one end of the half nut fixing plate is rotatable on a fixing pin. A pair of center half nuts which are attached to each other to be engaged to hold the uneven parts of the center column and to hold the uneven parts;

A half is attached to the lower side of the half nut fixing plate, and is formed to rotate each of the pair of center half nuts in the direction of wrapping the uneven portion of the center column by rotating the piston rod in or out of the uneven portion Cylinder for nut operation;

A column guide formed to cover the center column to guide the reciprocating movement of the center column in front of the pair of center half nuts;

Characterized in that configured to include.

In addition, the pair of center half nut is characterized in that it is configured to open and close operation by both connecting links connected to the reciprocating port formed on the end of the piston rod of the cylinder for half-nut operation.

In addition, the reciprocating port is attached to the front end of the piston rod of the half-nut operating cylinder is characterized in that configured to reciprocate in a straight direction between the guide plates fixedly attached to the half-nut fixing plate.

In addition, the column guide is characterized in that it comprises a guide support bar that is supported on each of the four tie bars supported on the four corners of the first and second fixed mold plate.

DETAILED DESCRIPTION Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a planar cross-sectional view showing an installation state of a molding apparatus of an injection molding machine for explaining the present invention, Figures 2 to 5 is a view showing an operating state of the molding apparatus of the present invention, Figure 6 is a line AA of Figure 1 Fig. 7 and Fig. 8 are diagrams showing the operation state of the center half nut of the mold clamping apparatus of the present invention.

Reference numerals 1a and 1b denote first and second fixed mold plates fixedly mounted to the injection molding machine, and four tie bars 2 are formed at each corner of each of the first and second fixed mold plates 1a and 1b. The connection is installed.

A fixed mold 3a is detachably mounted to the first fixed plate 1a, and a booster cylinder 4 is mounted to the second fixed plate 1b, and a booster ram 41 is mounted to the booster cylinder. It is mounted so as to be movable in the forward and backward directions by this hydraulic pressure.

The pressure chamber 4 is divided into the first chamber 42 and the second chamber 43 by the boosting ram 41, and the chambers 42 and 43 are formed in a very small space. Even if a small amount of hydraulic pressure is supplied to the selected one of the first and second chambers 42 and 43 of the boosting cylinder 4, the boosting ram 41 can be moved toward the forward or backward direction with a strong force. Will be.

A movable plate 5 is installed between the first and second fixed plate plates 1a and 1b so as to reciprocate in the front and rear directions along the plurality of tie bars 2 and the front of the movable plate. The center die 6 is provided with a movable mold 3b detachably attached thereto, and a rear side of the center column 6 is provided on the rear surface of the hollow portion 44 formed at the center of the boosting ram 41 of the boosting cylinder 4 to enable reciprocating movement. Is formed.

An end portion of the center column 6 is formed with an uneven portion 61 in which a plurality of ring protrusions and ring grooves are alternately repeated.

The second fixed mold 1b is provided with a mold transfer cylinder 7 having a cylinder body fixed to both left and right sides thereof, and the tip of the piston rod 71 of the mold transfer cylinder 7 is the movable plate. Is connected to (5). Therefore, the movable die 5 moves forward toward the first stationary die 1a or moves backward in the opposite direction as the piston rod 71 is released from the mold transfer cylinder 7.

The present invention is characterized in that, by using the center column (6) in the forward operation of the movable mold (5) to mold the movable mold (3b) to the fixed mold (3a) and then to the pressure-increase operation of the booster cylinder (4) Thus, the boosting ram 41 presses the movable die 5 to provide a clamping device for maintaining the clamping force of the stationary mold 3a and the movable mold 3b.

To this end, the center column 6 on the free surface (right side in the drawing) of the boosting ram 41 mounted on the boosting cylinder 4, that is, the free surface exposed to protrude to one side from the boosting cylinder 4. A pair of center half nuts 8 for holding or releasing the uneven portions 61 of the concave-convex portion 61, and the center column 6 to accurately hold the center column 6 by the pair of center half nuts. ) Is provided with a column guide (9) for holding the center column (6) to reciprocate movement so that the injection molding machine is not oriented to one side by vibration or the like.

The pair of center half nuts 8 are composed of two half nuts 8a and 8b formed in a semicircular cross section so as to wrap the center column 6 in half (see Fig. 7, 8). The upper ends of both half nuts 8a and 8b of the center half nut 8 of the center half nut 8 are fixed to the half nut fixing plate 81 formed by being fixed to the free surface of the booster ram 41 by the fixing pin 81. It is attached rotatably.

In addition, a half nut operating cylinder 83 is formed below both of the half nut 8a and 8b, and a reciprocating port attached to the tip of the piston rod 84 of the half nut operating cylinder 83 One end of each of the two connecting links 86 and 87 is rotatably connected to 85.

Each of the free ends of the two half nuts 8a and 8b forming the pair of center half nuts 8 is connected to the free ends of the connection links 86 and 87 described above. Therefore, the half nut operating cylinder (83) actuates the piston rod (84), so that both connecting links (86) (87) connected to the reciprocating port (85) reciprocating therewith are both half nut (8a) (8b) is loosened or engaged at the uneven portion 61 of the center column 6.

In addition, the reciprocating port 84 reciprocating as the piston rod 84 of the half nut operating cylinder 83 is reciprocated to move reciprocally in a straight line at all times without being biased to one side. The stationary plate 82 is provided with both side guide plates 88 that support both sides of the reciprocating port 84 so as to be slidable.

In addition, the front of the pair of center half nut (8) is further provided with a column guide (9) for supporting the center column (6) in a state capable of reciprocating movement.

The column guide 9 is provided with a bushing 91 for slidably moving the center column 6, and the column guide 9 is slidably supported by the plurality of tie bars 2. A plurality of guide support bars 92 are formed.

Each guide support bar 92 of the column guide 9 may be supported by a total of four tie bars 2 supported by four corner portions of each of the first and second fixed mold plates 1a and 1b. It is formed in a "x" shape so that.

Meanwhile, the half nut operating cylinder 83 for operating the pair of center half nuts 8 is attached to the half nut fixing plate 82 to detect an operating state of both half nuts 8a and 8b (not shown). Structure is controlled by the following method.

The operation of the mold clamping apparatus of the present invention configured as described above will be described.

First, FIG. 1 shows a state in which the movable mold 3b is opened in the stationary mold 3a, that is, the state in which the movable mold 3b is relaxed in the stationary mold 3a. In this case, a pair of center hub nuts The piston rod 71 of both the mold transfer cylinders 7 is reversed (immersed) in the state where the center column 6 is released (8) (see FIG. 7), and the movable plate 5 is of the second fixed type. The center column 6 is also moved backward to the plate 1b, and the uneven portion 61 at the end thereof penetrates the hollow 44 of the booster ram 41, thereby increasing the pressure-increasing cylinder 4. ) It protrudes backward.

2 shows the piston rod 71 of both mold transfer cylinders 7 moving forward (outside) to move the movable plate 5 forward to mold the movable mold 3b to the stationary mold 3a. In this case, the movable mold 3b and the stationary mold 3a are not in close contact with each other, and the uneven portion 61 of the center column 6 is moved forward with the movable mold 5. The end part is positioned inside the pair of center half nuts 8 in a state spanning the hollow 44 of the booster ram 41.

3 shows a state in which the pair of center half nuts 8 operate to hold the uneven parts 61 of the center column 6 in a state before the booster cylinder 4 is operated, in which case the half nut When the piston rod 84 of the operation cylinder 83 moves the reciprocating port 85 downward by the reverse (immersion) operation, both connecting links 86 and 87 are retracted, and both half nuts 8a (8b) is in a closed state, and the convex portions and recesses formed on the inner surfaces of each of the two half nuts (8a) and (8b) closed in this manner are engaged with the ring protrusion and ring groove of the concave-convex portion (61). The pair of center half nuts 8 are firmly caught by the uneven parts 61 of the center column 6.

4 shows a state in which the boosting cylinder 4 moves the boosting ram 41 forward by the boosting operation. In this case, when the boosting ram 41 presses the half nut fixing plate 82, the pressing force is increased. It is transmitted to the pair of center half nuts 8, whereby a pair of center half nuts 8 engaged with the uneven portion 61 moves the center column 6 toward the stationary plate 1a, thereby moving the mold. 3b) is in a state of being completely in contact with the stationary mold 3a. Therefore, the fixed mold (3a) and the moving mold (3b) is to maintain the clamping force while the pressure-increasing operation of the pressure-increasing cylinder (4).

Meanwhile, the boosting operation of the boosting cylinder 4 which pressurizes the boosting ram 41 in order to maintain the clamping force as described above is a state in which a small amount of hydraulic pressure supplied to the first chamber 42 is possible. Since a small amount of hydraulic pressure can be supplied to the first chamber 42 in a very short time, the time required to maintain the clamping force can be shortened.

5 shows that after molding the product by injecting a plastic molten raw material into the cavity of the stationary mold (3a) and the movable mold (3b) while maintaining the clamping force release the clamping force of the stationary mold (3a) and the movable mold (3b) In this case, a small amount of hydraulic pressure is supplied to the second chamber 43 of the booster cylinder 4 to move the booster ram 41 backward. At the same time, the reverse movement is performed, whereby the mold clamping force is released from the stationary mold 3a to open the mold.

When the clamping force is released as described above and the movable mold 3b is released from the stationary mold 3a, the mold 3b is completely removed from the stationary mold 3a to release the injection molded product. In this case, the demolding operation is performed in a reverse order to the order of the mold closing operation of the movable mold 3b to the stationary mold 3a.

According to the present invention as described above, the column guide supporting the center column wrapped state guides the center column moving forward and backward in a straight line with the moving plate while the pair of center half nuts are uneven parts of the center column. It provides the effect of precisely engaging and relaxing the pressure, and the pressure-increasing cylinder for maintaining the clamping force of the injection mold can pressurize the ammonia ram with the increased pressure even if a small amount of hydraulic pressure is supplied to the first chamber of the small space. It is possible to improve the productivity of the injection molding machine by providing the effect of shortening the time for generating the clamping force, and also to maintain the clamping force by using a pair of center half nuts installed while wrapping the center column. Therefore, it has the advantage of reducing the production cost of the injection molding machine.

Claims (4)

First and second fixed mold plates on which both ends of the tie bars are supported, fixed molds detachably mounted to the first fixed mold plates, movable mold plates movably installed on the plurality of tie bars, and the movable mold plate. A movable mold detachably installed to face the fixed mold on the front surface, a boosting cylinder formed on the second fixed mold plate, a boosting ram movably mounted on the boosting cylinder, and attached to a rear surface of the movable mold plate. In the injection molding machine having a center column protruding to penetrate the center of the boosting ram and the boosting cylinder, and a plurality of mold transfer cylinders for reciprocating the movable die back and forth, An uneven portion in which a plurality of ring protrusions and ring grooves are alternately continuously formed at an end of the center column reciprocating the hollow portion formed at the center of the boost ram; A half nut fixing plate fixedly attached to a free surface of the boosting ram exposed to protrude to one side from the boosting cylinder; A cross section is formed in a semicircular shape so as to cover half of the center column, and a plurality of convex parts and concave parts are formed on an inner circumferential surface of the center column, and one end of the half nut fixing plate is rotatable on a fixing pin. A pair of center half nuts which are attached to each other to be engaged to hold the uneven parts of the center column and to hold the uneven parts; A half is attached to the lower side of the half nut fixing plate, and is formed to rotate each of the pair of center half nuts in the direction of wrapping the uneven portion of the center column by rotating the piston rod in or out of the uneven portion Cylinder for nut operation; A column guide formed to cover the center column to guide the reciprocating movement of the center column in front of the pair of center half nuts; Molding apparatus of an injection molding machine, characterized in that configured to include. The method of claim 1, The pair of center half nuts are clamping devices of the injection molding machine, characterized in that the opening and closing operation by the two side connecting links connected to the reciprocating port formed on the tip of the piston rod of the half nut operating cylinder. The method of claim 1, The reciprocating port is attached to the front end of the piston rod of the half-nut operation cylinder is configured to reciprocate in a straight direction between the guide plates fixedly attached to the half-nut fixing plate. The method of claim 1, The column guide has a clamping device of the injection molding machine, characterized in that it comprises a guide support bar that is supported on each of the four tie bars supported on the four corners of the first and second fixed mold plate.

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