JPH0584765A - Mold clamping device of transfer molding machine - Google Patents

Abstract

PURPOSE:To provide a miniaturized mold clamping device having a simple structure and to prevent the contamination of a molded product and the lateral shift of a lower mold mounting plate. CONSTITUTION:The stator 32 of an electromotive direct drive motor 31 is fixed on a base 11 and a nut 35 is fixed to the rotor 33 of the motor 31. The ball screw 36 threaded with the nut 35 is fixed to a lower mold mounting plate 14. By this structure, the rotation of the rotor 33 is converted to up and down movement to be transmitted to the lower mold mounting plate 14. The greater part of the up and down stroke of the lower mold mounting plate 14 is generated by the driving of the motor 31 but the final mold clamping pressure is generated by a hydraulic cylinder 25. By this constitution, different from such a case that the lower mold mounting plate 14 is driven by the motor 31 through a toggle mechanism, no force in a horizontal direction is applied to the lower mold mounting plate 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device for a transfer molding machine.

[0002]

2. Description of the Related Art For example, in resin packaging of IC chips, transfer molding using a thermosetting resin is carried out. A transfer molding machine used for this is a mold including an upper mold and a lower mold. A mold clamping device that opens and closes the mold by moving the mold in the vertical direction, and a transfer device that transfers the resin to a mold cavity formed in the mold in the mold clamped state are provided. .. In the mold clamping device, for example, an upper mold mounting plate to which an upper mold is mounted is fixed to an upper end of a rod erected on a base, and a lower mold is mounted to an intermediate position of the rod. The mold mounting plate is supported so as to be movable in the vertical direction, and the lower mold mounting plate is raised to perform mold clamping. In the conventional mold clamping device, the lower mold mounting plate is vertically driven by the hydraulic cylinder device over its entire stroke. However, in that case, the amount of oil used in the hydraulic cylinder device is increased, and the increased amount of oil increases the risk of the molded product being contaminated with the leaked oil. This is a problem particularly in a molded product in which stains such as IC chips, which must be molded in a clean room, are undesirable.

Therefore, a mold clamping device has been developed in which the lower mold mounting plate is vertically driven by an AC servomotor via a toggle mechanism. However, in this conventional mold clamping device, a high-output motor is required, and since the toggle mechanism is arranged between the base and the lower mold mounting plate, the motor and speed reducer are placed outside the base. It must be installed, and the molding machine becomes large. Also, since the toggle mechanism is used, a force is also applied to the lower mold mounting plate in the horizontal direction, which may cause lateral displacement of the lower mold mounting plate, and also the load on the lower mold mounting plate and rod. Therefore, high strength is also required.

[0004]

As described above, in the mold clamping device of the conventional transfer molding machine, since the lower die mounting plate is driven by the hydraulic cylinder device over the entire stroke thereof, the leaked oil is lost. However, there is a problem that the molded product may become dirty. On the other hand, in the conventional mold clamping device in which the lower die mounting plate is vertically driven by the AC servo motor via the toggle mechanism, the size of the conventional die clamping device is increased and a force is applied to the lower die mounting plate in the horizontal direction. Therefore, there is a problem that the lower die mounting plate may be laterally displaced.

The present invention is intended to solve such a problem, and in addition to preventing the molded product from being contaminated, the structure is simple and the size can be reduced, and the lower die is laterally displaced. An object of the present invention is to provide a mold clamping device for a transfer molding machine that does not have such a risk.

[0006]

In order to achieve the above-mentioned object, the present invention aims to achieve the above-mentioned object by moving the lower mold of a mold composed of an upper mold and a lower mold in the vertical direction. In a mold clamping device of a transfer molding machine that performs mold opening and mold clamping, a base, an upper mold supporting member provided above the base, and a vertical movement between the base and the upper mold supporting member are possible. A lower die supporting member supported on the base, an electric direct drive motor in which a stator is fixed on the base, and rotation of a rotor of the direct drive motor is converted into vertical movement to support the lower die. A nut and a screw for transmitting to the member, and a fluid pressure cylinder device for pressing the lower die supporting member relatively upward with respect to the base are provided.

[0007]

In the mold clamping device of the transfer molding machine of the present invention, the upper mold is supported by the upper mold supporting member and the lower mold is supported by the lower mold supporting member to perform the transfer molding.
At the time of mold clamping and mold opening, the rotation of the rotor of the electric direct drive motor in which the stator is fixed on the base is converted into vertical movement by the nut and the screw and transmitted to the lower die supporting member, As a result, the lower die support member moves up and down. At this time, no horizontal force is applied to the lower die supporting member. In addition, after the lower mold supporting member is lifted by the drive of the direct drive motor, the lower mold supporting member is further pressed upward relative to the base by the fluid pressure cylinder device, and a sufficient mold clamping pressure is obtained. Is generated.

[0008]

An embodiment of the present invention will be described below with reference to the drawings showing a transfer molding machine. In the drawings, 1 is an upper mold, 2 is a lower mold, and a mold cavity 3 is formed between these clamped upper mold 1 and lower mold 2. A shot cavity 4 communicating with the die cavity 3 is formed in the upper die 1. The transfer molding machine then moves the lower mold 2 in the vertical direction to open and close the molds 1 and 2 and a mold clamping device 6, and from the shot cavity 4 to the mold cavity 3 in the mold clamping state. And a transfer device 7 for transferring the resin.

Next, the structure of the mold clamping device 6 will be described in detail. 11 is a base, 12 is an upper die mounting plate which is an upper die supporting member located above the base 11, and the base 11 and the upper die mounting plate 12 are four rods.
It is connected and fixed by 13. The upper die mounting plate 12
The upper mold 1 is detachably fixed to the lower side. A lower mold mounting plate 14, which is a lower mold supporting member, is supported by the rod 13 between the base 11 and the upper mold mounting plate 12 so as to be vertically movable.
The lower mold mounting plate 14 is such that the lower mold 2 is detachably fixed to the upper side. Also, on the base 11,
An annular turntable 16 is horizontally rotatably supported by rollers 17. At the same time, a pneumatic cylinder device for driving the rotary disk 16 to rotate is provided outside the base 11.
18 are provided. A rack 20 fixed to a piston rod 19 of the cylinder device 18 meshes with a pinion 21 fixed to the outer peripheral portion of the rotary disc 16. A plurality of cylindrical first lower supports 22 and second lower supports 23 are erected on the circular rotary disc 16 while being positioned on the circumference around the rotary shaft of the rotary disc 16. Has been done. The upper end of the first lower support 22 is located higher than the upper end of the second lower support 23. On the other hand, on the lower surface of the lower die mounting plate 14, a plurality of first upper supports 24 located on a cylindrical surface passing through the lower supports 22 and 23 and corresponding to the first lower supports 22 respectively.
And a hydraulic cylinder device 25, which is a fluid pressure cylinder device corresponding to each of the second lower supports 23, is attached. Then, the piston rod 26 of the hydraulic cylinder device 25 that moves up and down is
Upper supports 27 are vertically provided. The upper end of the first upper support 24 is located higher than the upper end of the second upper support 27. A hydraulic cylinder device is provided on the side of the base 11.
An oil supply 28 for 25 is provided.

Reference numeral 31 is an electric direct drive motor. This motor 31 is, for example, a Dynaserve (trade name) manufactured by Yokogawa Precision Co., Ltd., and a cylindrical rotor 33 is coaxial with an outer peripheral side of a cylindrical stator 32. It is located at the target. The stator 32 is fixed on the base 11 at a position inside the circular rotary plate 16. A disc 34 is fixed on the rotor 33, and a nut 35 is fixed to the center of the disc 34. On the other hand, a ball screw 36 is fixed to the central portion of the lower die mounting plate 14 so as to project downward, and the ball screw 36 is screwed to the nut 35. The central axes of the ball screw 36 and the nut 35 coincide with the rotation axis of the rotor 33. Thus, the nut 35 and the ball screw 36 cause the rotor
The rotation of 33 is converted into vertical movement and the lower die mounting plate 14
To be transmitted to. The motor 31
Between the stator 32 and the rotor 33 of the radial bearing
37 intervenes. Further, a thrust bearing 38 is interposed between the base 11 and the lower end surface of the rotor 33. Further, a sleeve 39 is fixed on the base 11 so as to surround the motor 31, and an annular ring 40 is fixed to the upper end surface of the sleeve 39. And this ring
A thrust bearing 41 is interposed between the lower surface of 40 and the upper end surface of the rotor 33. However, the rotor 33 is allowed to move up and down slightly between the upper and lower thrust bearings 38 and 41. Further, the ring 40 is provided with a pneumatic cylinder device 42, and a vertically moving piston rod 43 of the cylinder device 42 is fixed to a disk 34 on the rotor 33. The piston rod 43 is urged downward by a spring 44 and is raised when pressurized by air.

Next, the structure of the transfer device 7 provided on the upper die mounting plate 12 will be described in detail. A nut 52 is supported in a housing 51 fixed on the upper die mounting plate 12 so as to be horizontally rotatable only. That is, this nut 52 cannot move in the vertical direction.
The pulley 53 is fixed to the outer circumference of the nut 52. Further, a motor 54 is provided at a side position of the upper die mounting plate 12, and an output shaft 55 of the motor 54 is provided.
A timing belt 57 is stretched between a pulley 56 fixed to and a pulley 53 around the nut 52.
A ball screw 58 is screwed into the nut 52, and a plunger 59 is integrally provided at the lower end of the ball screw 58. The ball screw 58 is inserted into the shot cavity 4 of the upper die 1 through the through hole 60 formed in the upper die mounting plate 12. With such a configuration, when the output shaft 55 of the motor 54 rotates, this rotation is transmitted to the nut 52 via the pulleys 56, 53 and the belt 57, and the ball screw screwed into the nut 52 is accompanied by the rotation. 58 moves up and down. On the other hand, a receiving plate 61 is fixed to the upper end portion of the ball screw 58, and the receiving plate 61 is supported by a rod 62 erected on the housing 62 so as to be vertically movable. And
A stopper piece 63 is fixed to the upper ends of these rods 62.

Next, the operation of the above configuration will be described. The transfer molding machine is used, for example, for resin packaging of an IC chip with a thermosetting resin, and at the time of transfer molding, an upper die mounting plate.
Attach the upper mold 1 to 12 and lower mold mounting plate
Attach the lower mold 2 to 14. And before clamping the mold,
, The lower mold mounting plate 14 is in the lowered position,
The lower end surface of the first upper support 24 of the lower die mounting plate 14 is in contact with the upper end surface of the first lower support 22 of the turntable 16.
On the other hand, the second lower support 23 of the turntable 16 and the second upper support 27 of the lower die mounting plate 14 are positioned so as to be offset from each other in the horizontal direction. In such a mold open state, the resin material is loaded into the shot cavity 4 of the upper mold 1. Next, at the time of mold clamping, first, the direct drive motor 31 is actuated, and the rotor 33 thereof horizontally rotates forward. When the rotor 33 rotates forward in this way, the rotor 33
The nut 52 horizontally rotates forward together with the nut 52, and the ball screw 58 screwed to the nut 52 rises. This allows
Lower mold mounting plate 14 to which this ball screw 58 is fixed
And the lower mold 2 also rises, and the lower mold 2 approaches the upper mold 1 and is in a substantially clamped state. Then, the cylinder device 18
The rotary disc 16 is rotated by the driving of the rotary table 16 so that the second lower support 23 of the rotary disc 16 and the second upper support 27 of the lower mold mounting plate 14 are aligned in the vertical direction, and the upper surface of the second lower support 23 is The lower end surface of the second upper support 27 is brought into a state of being closely opposed. Then, the piston rod of the hydraulic cylinder device 25
26 descends, and the second upper support 27 is pressed against the second lower support 23. As a result, the lower mold mounting plate 14 is relatively pressed upward with respect to the base 11, and the lower mold 2 is pressed against the upper mold 1 to be in a final mold clamping state. At that time, the mold clamping pressure is received by the second upper support 27 and the second lower support 23 that are in contact with each other. Then, in the mold clamping state as shown in FIG. 2, the motor 59 of the transfer device 7 is driven to lower the plunger 59 via the nut 52 and the ball screw 58. The resin is transferred from the shot cavity 4 to the mold cavity 3 by the descending plunger 59. Next, the mold is opened, but when the mold is opened, the pressing by the hydraulic cylinder device 25 is released, and the lower mold attachment plate 14 is slightly raised by the drive of the cylinder device 42, and the second upper support 27 is moved to the second position. A little away from the lower support 23. Then, the turntable 16 is rotated by the drive of the cylinder device 18, the second lower support 23 of the turntable 16 and the second upper support 27 of the lower die mounting plate 14 are disengaged, and the first lower support 22 and the first lower support 22 are removed. 1 The upper support 24 is aligned. Then, the direct drive motor 31 operates and the rotor 33 rotates in the reverse direction. Rotor like this
When 33 rotates in the reverse direction, the nut 52 rotates in reverse together with this, and the ball screw 58 descends. As a result, the lower die mounting plate 14 and the lower die 2 are also lowered until the first lower support 22 hits the first upper support 24, and the lower die 2 is separated from the upper die 1.

According to the construction of the above-mentioned embodiment, most of the total stroke of the lower die mounting plate 14 at the time of mold clamping is caused by the electric direct drive motor 31, and the stroke by the hydraulic cylinder device 25 is small. Therefore, the hydraulic cylinder device 25 that uses less oil can be adopted. Therefore, it is possible to prevent the molded product such as an IC from being damaged by the leaked oil. Nevertheless, since the final mold clamping pressure is generated by the hydraulic cylinder device 25, a sufficiently strong mold clamping pressure can be obtained. Further, the nut 35 and the ball screw 36, etc., which transmit the power of the direct drive motor 31 to the lower mold mounting plate 14 are weak in strength themselves, but since the supports 23 and 27 receive the mold clamping pressure, the nut 35 The ball screw 36, etc. is not overloaded. Further, a direct drive motor 31 is adopted as a drive source for the lower die mounting plate 14, the stator 32 thereof is fixed to the base 11, and the rotation of the rotor 33 is converted into vertical movement by a nut 35 and a ball screw 36. Since it is transmitted to the lower mold mounting plate 14 by means of a lower mold mounting plate 14, the structure of the mold clamping device 6 becomes simpler than in the case where the lower mold mounting plate is driven vertically by an AC servomotor via a toggle mechanism. The mold clamping device 6 can be downsized. In addition, when the lower mold mounting plate 14 is driven by the direct drive motor 31, no force is applied to the lower mold mounting plate 14 in the horizontal direction, and the lower mold mounting plate 14 and the lower mold 2 are There is no lateral displacement and the lower mold mounting plate 14
It doesn't cost anything. Further, although the direct drive motor 31 is weak against the load in the thrust direction, it receives the mold clamping pressure by the supports 23 and 27 as described above, and the supports 22 and
In addition to receiving the load at the time of mold opening by 24, the rotor 33 is vertically moved to the base via thrust bearings 38 and 41.
By supporting the above on 11, the direct drive motor 31 can be protected from the load in the thrust direction.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
In the above-described embodiment, the transfer molding machine in which the transfer device 7 is provided on the upper die 1 side has been described as an example.
Of course, the present invention can be applied to a transfer molding machine in which a transfer device is provided on the lower die side.

[0015]

According to the present invention, in a mold clamping device of a transfer molding machine, an electric direct drive motor drives a lower die supporting member in a vertical direction, and the lower die supporting member drives a direct drive motor. Then, the lower die support member is pressed upward relative to the base by the fluid pressure cylinder device. The lower die supporting member is an AC servo motor because it can prevent stains, and can convert the rotation of the rotor of the direct drive motor fixed on the base into vertical movement and transmit it to the lower die supporting member. The structure of the mold clamping device is simpler and the mold clamping device can be made smaller than when driven vertically through the toggle mechanism. Without force is applied in the horizontal direction on the lower die mounting plate, together with the lower die support members and the lower mold does not occur lateral displacement, not burdened like the lower die support member.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a transfer molding machine showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view of the same.

FIG. 3 is a horizontal sectional view of the same.

[Explanation of symbols]

 1 Upper mold 2 Lower mold 6 Mold clamping device 11 Base 12 Upper mold mounting plate (upper mold supporting member) 14 Lower mold mounting plate (lower mold supporting member) 25 Hydraulic cylinder device (fluid pressure cylinder device) 31 Direct drive motor 32 Stator 33 Rotor 35 Nut 36 Ball screw (screw)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H02K 7/06 A 6821-5H // B29L 31:34 4F

Claims (1)

[Claims] 1. A mold clamping device of a transfer molding machine, wherein a lower mold of a mold including an upper mold and a lower mold is moved in the vertical direction to perform mold opening and mold clamping of the mold, The base, the upper mold supporting member provided above the base, the lower mold supporting member movably supported in the vertical direction between the base and the upper mold supporting member, and the stator are the bases. An electric direct drive motor fixed on the upper side, a nut and a screw for converting the rotation of the rotor of the direct drive motor into vertical movement and transmitting the vertical movement to the lower die supporting member, and a lower metal for the base. A mold clamping device for a transfer molding machine, comprising: a fluid pressure cylinder device that presses a mold supporting member relatively upward.