JP2539947Y2 - Mold clamping device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping apparatus which moves a movable mold to generate a predetermined clamping force.

[0002]

2. Description of the Related Art Conventionally, as a molding apparatus for encapsulating a semiconductor element in a resin, for example, an apparatus shown in FIG. 4 is provided.

In this apparatus, a plurality of tie bars 2 are erected on a base 1, and an upper platen 3 is fixed on the tie bar 2. A slide plate 4 is vertically slidably fitted between the upper platen 3 and the base 1 on the tie bar 2, and a movable lower die 5 is fixed on the slide plate 4, and the upper platen An upper die 6 which is a fixed die is fixed below 3.

[0004] A housing 8 holding a nut 7 is mounted below the slide plate 4, and a ball screw 9 is screwed to the nut 7. Ball screw 9
, A pulley 10 is attached, and the pulley 10 and the pulley 11 are connected by a timing belt 12. The pulley 11 is connected to a servomotor 14 fixed on the base 1 via a mounting plate 13.

[0005] An oil passage 15 is provided in the base 1, and the oil passage 15 is filled with hydraulic oil 16. Oil passage 15
A pressure ram 17 is provided at the tip of the ball screw 9, and the ball screw 9 is erected on the pressure ram 17 via a thrust bearing 18. At the base end of the oil passage 15, an air booster 19 that pressurizes the hydraulic oil 16 with air force is provided. The amount of air supplied to the air booster 19 is adjusted by an electric / pneumatic regulator 20. The mold clamping force is fed back to the regulator 20 by a load cell 21 provided on the pressure ram 17.

[0006] With the above configuration, at the time of mold clamping, the servomotor 14 is first activated to apply a rotational force to the ball screw 9 in the path of the pulley 11-the timing belt 12-the pulley 10. Then, the nut 7 is screwed upward along the ball screw 9 to raise the slide plate 4 via the housing 8. This slide plate 4
Is raised at a high speed and at a low pressure until the lower die 5 is pressed against the upper die 6. After the lower die 5 is pressed against the upper die 6, the hydraulic oil 16 is pressed by the air booster 19 and pressurized. Push up the ram 17. Then, as a result, the ball screw 9 is raised, and the slide plate 4 is also raised via the nut 7 and the housing 8, so that the lower die 5 is further pressed against the upper die 6, and the die is clamped. At this time, the pressure value obtained by the load cell 21 is
By feeding back to 0, the electric / pneumatic regulator 20 adjusts the air force applied by the air booster 19 to the hydraulic oil 16 so that a predetermined mold clamping force can be obtained.

After the mold is clamped, a resin is injected into the lower die 5 and the upper die 6 by a resin injection device (not shown), and molding for encapsulating the semiconductor element with resin is performed. When removing the molded product, the lower mold 5 is lowered by the reverse operation.

[0008]

When the mold is clamped as described above, the torque by the servomotor 14 for moving the lower mold 5 at a high speed is reflected in the mold clamping force, although the pressure is low. For this reason, the mold clamping force adjusted by the electro / pneumatic regulator 20 becomes smaller than the pressure actually required.
That is, the electro / pneumatic regulator 20 adjusts the mold clamping force based on the pressure value fed back from the load cell 21, and the pressure value fed back from the load cell 21 includes the torque by the servomotor 14. Not only the pressure of the pressure ram 17. For this reason, the mold clamping force determined by the electro / pneumatic regulator 20 that adjusts the pressure of the pressurizing ram 17 does not become an accurate pressure, but is reduced by the torque of the servomotor 14.

In the above-mentioned structure, the lower mold 5 is connected to the upper mold 6
The mechanism for pressurizing the oil at a high pressure
The lower part of the lower mold 5 when opening the mold is limited by the lower part of the ball screw 9. For this reason, there is a drawback that workability such as removal of a molded product and setting of a semiconductor element performed after opening the mold is not good.

Further, the use of a hydraulic mechanism has a problem of causing oil leakage.

On the other hand, instead of the air booster 19 described above,
After the servo motor 14 is stopped using a motor (second motor), the motor is rotated at a constant torque by limiting the torque, so that the ball screw 9 is further rotated to raise the slide plate 4. it was thought.

However, in this method, as shown in FIG. 5, even if the motor is rotated at a constant torque, the actually generated mold clamping force is greatly different due to the difference in the initial rotation speed. However, it was difficult to achieve accurate mold clamping force.

[0013] The present invention has been made in view of the above-mentioned circumstances, and the object thereof is to provide a mold clamping force that can be accurately generated at an actually required pressure, and that a large mold opening can be ensured. , While improving the workability of the work performed after opening the mold, without causing oil leakage, etc.
An object is to provide an excellent mold clamping device that can be used cleanly.

[0014]

In order to achieve the above object, in a mold clamping device according to the present invention, a first motor comprising a driving means for moving a movable mold and a servomotor for driving the driving means, A second motor for driving the driving means separately from the first motor; and a control means for controlling the first and second motors.
When the driving means is driven by the second motor, the rotation position of the first motor, which is driven and rotated, is fed back to perform control for generating a predetermined clamping force set in advance. It is assumed that.

[0015]

According to the above means, the movable mold is first moved by the first motor, and then moved by the second motor. At this time, since the first motor is driven to rotate, the rotation position is fed back to the control of the second motor, and the first motor is rotated to a rotation position at which a predetermined mold clamping force is generated. Drive the second motor until is reached.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, in FIG. 1, a plurality of tie bars 32 are erected on a base 31, and an upper platen 33 is fixed on the tie bars 32. A slide plate 34 is vertically slidably fitted between the upper platen 33 and the base 31 on the tie bar 32. A movable lower die 35 is fixed on the slide plate 34, and the upper platen An upper die 36, which is a fixed die, is fixed below 33.

A housing 38 holding a nut 37 is mounted below the slide plate 34, and a ball screw 39 is screwed onto the nut 37 so as to function as driving means. The ball screw 39 stands on the base 31 via a thrust bearing 40. or,
A pulley 41 is attached to the ball screw 39, and the pulley 41 and the pulley 42 are connected by a timing belt 43. The pulley 42 has a first motor 45 composed of a servomotor fixed on the base 31 via a mounting plate 44.
It is connected to.

A second motor 46, which is also a servomotor, is fixed to a portion of the base 31 opposite to the first motor 45 via a mounting plate 47. A reduction gear 48 having a high reduction ratio is attached to the second motor 46, and a pulley 49 is connected to the reduction gear 48. Pulley 49
Is the timing belt 5 between the clutch pulley 50 and
1, the clutch pulley 50 is driven by an electromagnet or the like (not shown) driven by a command from the control device 52.
The pulley 41 is connected to the pulley 41.

The control device 52 controls the first motor 45 and the second motor 46 in addition to controlling the clutch pulley 50.
Of the first commander 53 and the second commander 54 function as control means. Of the two commanders 53 and 54, the first commander 53
Is fed back from the first motor 45 with rotation position information by a position detector such as a resolver (not shown), and gives a rotation command to the first motor 45. The second commander 54 Similarly, the rotational position information is fed back from the first motor 45, and the rotational position information is also fed back from a second motor 46 by a position detector such as a resolver (not shown), and a rotation command is given to the second motor 46. Is to give. The control device 52 issues a command to both of the command devices 53 and 54 based on a signal from the set pressure input device 55.

With the above configuration, first, at the time of mold clamping, the first
, A rotational force is applied to the ball screw 39 in the path of the pulley 42 -the timing belt 43 -the pulley 41. Then, the nut 37 is screwed upward along the ball screw 39 to raise the slide plate 34 via the housing 38. The raising of the slide plate 34 is performed at a high speed and a low pressure until the lower mold 35 presses against the upper mold 36.
When the first motor 45 is pressed, the first motor 45 is stopped, and the position is input to the control device 52 by the position detector and stored. At this time, the clutch pulley 50 is connected to the pulley 41.

Next, by activating the second motor 46, a rotational force is applied to the ball screw 39 in the path of the speed reducer 48-pulley 49-timing belt 51-clutch pulley 50-pulley 41, and the nut 37 and the housing are provided. 3
The lower mold 35 is further raised together with the slide plate 8 and the slide plate 34 to perform mold clamping. At this time, since the pulley 41 is also rotated, the first motor 45 is driven and rotated along the reverse path of the timing belt 43 and the pulley 42. The driven rotation of the first motor 45 is accompanied by the extension of the tie bar 32, the contraction of the ball screw 39, and the deflection of the upper platen 33 and the slide plate 34. Accordingly, the amount of the extension, contraction, and deflection is reduced. The sum is also the driven rotation amount of the first motor 45, which is a deflection amount proportional to the force of the elastic body. Therefore, a proportional constant is obtained from the actually required mold clamping force previously measured by a load cell and the amount of the driven rotation of the first motor 45, and based on this, the mold set and input from the set pressure input device 55 is obtained. The rotation amount of the first motor 45 is determined from the tightening force, and the second motor 46 is rotated until the first motor 45 reaches this rotation amount.

FIG. 2 shows the relationship between the pulse (rotation amount) generated by the position detector based on the rotation of the first motor 45 at this time and the mold clamping force.

In the above-described mold clamping,
The mold clamping force is accurately reflected on the rotation of the first motor 45,
Since the second motor 46 is rotated based on this, it is possible to accurately generate the mold clamping force at the actually required pressure.

Further, a mechanism for pressing the lower die 35 to the upper die 36 at a high pressure, such as the conventional pressurizing ram 17 and the oil passage 15, is not required below the ball screw 9, so that a large opening amount of the die is ensured. Thus, it is possible to improve the workability of operations such as taking out a molded product and setting a semiconductor element performed after opening the mold.

Further, since no hydraulic mechanism is employed, the device can be used cleanly without causing oil leakage or the like.

FIG. 3 shows a different embodiment of the present invention, wherein the second motor comprises the above-mentioned servo motor.
6 is replaced with a motor 56 consisting of an induction motor with a brake,
Is controlled via a command unit 57 of the second motor 5 after the first motor 45 stops.
When the first motor 45 reaches the set rotation amount by rotating the motor 6, the braking of the second motor 56 is stopped, so that an accurate mold clamping force can be generated as described above. Further, in this case, by using an ordinary motor called an induction motor as the second motor 56, the feedback control for the second motor 56 becomes unnecessary, and the configuration can be simplified as compared with the above.

[0028]

As is apparent from the above description, the mold clamping device of the present invention has a first motor including a driving means for moving a movable mold, and a servomotor for driving the driving means.
A second motor for driving the driving means separately from the first motor;
And control means for controlling these first and second motors, and the control means controls the rotation position of the first motor that is driven and rotated when the drive means is driven by the second motor. By using feedback to control to generate a predetermined mold clamping force set in advance, the mold clamping force can be accurately generated at the actually required pressure, and a large mold opening amount is secured. As a result, the workability of the work performed after opening the mold can be improved, and there is an excellent effect that it can be used cleanly without causing oil leakage or the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a characteristic diagram

FIG. 3 is a block diagram showing a different embodiment of the present invention.

FIG. 4 is a configuration diagram showing a conventional example.

FIG. 5 is a characteristic diagram showing a different conventional example.

[Explanation of symbols]

35 is a lower mold (movable mold), 37 is a nut (driving means), 3
9 is a ball screw (drive means), 45 is a first motor, 4
6 is a second motor, 52 is a control device (control means), 53
Denotes a first commander (control means), 54 denotes a second commander (control means), 56 denotes a second motor, and 57 denotes a second commander (control means).

Claims (1)

(57) [Scope of request for utility model registration] 1. A driving means for moving a movable mold, a first motor comprising a servomotor for driving the driving means, a second motor for driving the driving means separately from the first motor, Control means for controlling the first and second motors, and the control means feeds back the rotational position of the first motor that is driven and rotated when the drive means is driven by the second motor. A mold clamping device, characterized in that the mold clamping device is configured to control to generate a predetermined mold clamping force set in advance.