JPH05329609A - Injection equipment - Google Patents

Abstract

PURPOSE:To avoid the effect of the machining accuracy of a machine by advancing an injection sleeve after pouring the molten metal into the sleeve, rotating a screw shaft after the injection sleeve is connected to a fixed sleeve within a die, and advancing a ball holder, and thereby advancing a plunger. CONSTITUTION:An injection equipment is provided with a rotational-linear movement transmission mechanism which is interposed between a motor and a supporting frame 18 and transmits the movement, and a screw shaft 21 which is pivotably supported by the frame and rotated by the motor. A ball holder 32 of a ball screw device which is fitted to these screw shafts and the supporting frame 18 to support the ball holder at its outer circumference are provided. In addition, a brake which is located to the lower part of the screw shafts and stops the rotation of the screw shaft and a plunger 34 supported by the supporting frame at its center part are provided. An injection sleeve 17 where a plunger chip 34a at the plunger tip which is mounted on the supporting frame in an elevatable manner relative to the supporting frame is fitted into an inner hole in such a manner as to freely advance and retreat is provided. This arrangement facilitates the rotation of the screw shaft and the transmission of the power.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection device for injecting molten metal into a cavity of a mold.

[0002]

2. Description of the Related Art An injection molding apparatus, for example, a die casting machine, which is a vertical casting type injection apparatus for injecting a molten metal into a cavity of a mold from below has been disclosed in Japanese Patent Laid-Open No. 1-224510.
The thing of the gazette is known. That is, an injection frame supported by a machine base or the like is hung in an underfloor pit provided under the mold, and the entire injection device is vertically supported by the injection frame.

This injection device has an injection cylinder connected to a hydraulic device, an injection sleeve supported concentrically with the injection cylinder on a vertically movable sleeve frame on the injection cylinder side, and a cup on the piston rod of the injection cylinder. And a plunger in which a plunger tip at the tip is connected through a ring and is inserted into an inner hole of the injection sleeve so as to be movable back and forth. Then, after pouring into the injection sleeve, the injection sleeve is advanced together with the plunger tip and joined to the fixed sleeve on the mold side, and the motor rotates the pair of screw shafts synchronously via the rotation-linear motion transmission mechanism. When driven, the ball holder is moved forward together with the support frame while rolling the ball in the ball groove, the plunger supported by the support frame moves forward, and the molten metal in the injection sleeve passes through the fixed sleeve and into the mold cavity. Is injected,
A cast product is obtained by solidifying this molten metal.

[0004]

However, in such a conventional injection apparatus, since a pair of screw shafts are synchronously driven to rotate, a malfunction is likely to occur due to the influence of misalignment or the like. The structure of the rotation-linear transmission mechanism that transmits the motion to the screw shaft that is rotationally driven by the motor becomes complicated. There was a problem.

[0005]

In order to solve such a problem, according to the present invention, there is provided a rotation-linear transmission mechanism which is interposed between a motor and a support frame to transmit a motion, and a shaft support to the frame. And one screw shaft that is driven to rotate by a motor, a ball holder of a ball screw device fitted to these screw shafts, a support frame that supports these ball holders on the outer peripheral portion, and further, A brake which is located at a lower position to stop the rotation of the screw shaft, a plunger supported at the center of the support frame, and a plunger tip at the tip of the plunger mounted so as to be movable up and down with respect to the support frame in an inner hole. An injection sleeve is provided which is fitted so as to move back and forth.

[0006]

[Function] After pouring into the injection sleeve, the injection sleeve is advanced together with the plunger tip and joined to the fixed sleeve on the mold side, and then the motor drives the screw shaft to rotate through the rotation-linear motion transmission mechanism, When the holder is moved forward together with the support frame while rolling the ball in the ball groove, the plunger supported by the support frame advances and the molten metal in the injection sleeve is pushed by the plunger tip and injected into the cavity of the mold. To be done.

[0007]

1 to 4 show an example in which an injection apparatus according to the present invention is applied to a vertical casting type die casting machine. FIG. 1 is a vertical sectional view of the injection apparatus, and FIG. FIG. 3 is a plan view of the injection device, and FIG. 4 is an elevation view seen from AA of FIG.

A pair of linear guides 2 (only one is shown) are fixed to a frame 1 located below a mold (not shown), and an injection device indicated by reference numeral 3 is guided by the linear guides 2. It is configured to move horizontally between the injection position below the mold shown in the figure and the pouring position which is the paper spine direction in the figure. That is, the linear guide 2 includes rails 5 each having a substantially square cross section and supported by a support plate 4 on the frame 1 side. A plurality of balls are provided in ball grooves formed on both side surfaces of the rail 5. 6 is rotatably held. A plurality of ball holders 9 each having an inverted U-shaped cross section and a side surface covered with a cover (not shown) are fixed to a cylindrical body 7 of the injection device 3 through a reinforcing member. A ball groove for holding the ball 6 is formed on the inner surface. With such a configuration, when driven by the drive device, the injection device 3
Moves smoothly while rolling the ball 6 in the ball groove.

The injection device 3 thus supported is
A polygonal upper frame 10 fixed to the upper end of the cylindrical body 7.
Docking schilling 12 provided at the opposite location
The lower portion of the ram 8 for docking cylinder is fitted in the ram hole 12a so as to be able to move up and down, and is fixed to the upper frame 10 via a linear ball bearing 36 in the middle. The upper portion of the docking cylinder ram 8 is fixed to the sleeve frame 15 with a plurality of bolts 16a, and a cylindrical injection sleeve 17 is provided above the sleeve frame 15 at the center thereof. It is fixed concentrically with a fixed sleeve (not shown) of the die.

On the other hand, as shown in FIG. 2, an elevating shaft 13 is provided at a position facing the docking cylinder 12 with a phase of approximately 60 degrees. An elevating shaft 13 extending upward from the vicinity of the lower end portion of the cylindrical body 7 is provided, and the lower end portion of the elevating shaft 13 is inserted through a guide cylinder 14 and a boss portion 18a formed in the lower frame 11, and A linear ball bearing 55 having a large number of balls 6a interposed between the upper portion of the guide cylinder 14 and the boss portion 18a.
56, and the upper end of the elevating shaft 13 is fixed to the sleeve frame 15 with a plurality of bolts 16b. Further, reference numeral 18 indicates an outer peripheral portion 2 in the circumferential direction.
The support frame is held by a boss portion 18a formed at equally divided positions.

A guide cylinder 1 below the lifting shaft 13
4, a locking member 2 disposed on the plurality of pins 22 in the vicinity of above
The lowering limit is regulated by 0, and the support frame 18
Is supported by a screw shaft 21 via a ball holder 33 so as to be vertically movable.

A bearing hole is formed in the lower frame 11 disposed below the support frame 18 at a position corresponding to the screw shaft 21, and the small diameter portion of the screw shaft 21 is inserted into the bearing hole. It is pivotally supported via 23.

The step portion of the screw shaft 21, the screw portion formed on the lower end of the screw shaft 21 and the screw portion formed on the inner peripheral portion of the bevel gear 25 can be screwed to each other. And screw them together, and then lock the key on the small diameter part.
A nut 26 is screwed into a threaded portion protruding from the lowermost end of the nut 1 to lock the nut 26, and movement of the nut 26 in the axial direction with respect to the lower frame 11 is restricted. Servo motors 2 horizontally arranged on both sides of the lower frame 11 opened downward
Bearing holes are bored at corresponding positions of the rotary shaft 28 of No. 7, radial bearings 29R and 29L are mounted in the bearing holes, and oil is also provided on both outer surface portions of the radial bearings 29R and 29L. A seal member 60 is provided, and the rotary shaft 28 is rotatably supported at its both ends by radial bearings 29R, 29L. An electromagnetic brake device 31 is disposed at a shaft end of the rotary shaft 28 at a side end of the lower frame 11, and an electromagnetic brake (not shown) in the electromagnetic brake device 31 is provided at a side end of the lower frame 11 as needed. The rotation shaft 28 is prevented from rotating by coming into contact with the portion.

The base of the rotary shaft 28 on the side of the servomotor 27 has a stepped portion, and the radial bearing 29R keyed to the large diameter portion and the small diameter portion are fitted and keyed. A bevel gear 25a is provided, and the bevel gear 25a is configured to mesh with the bevel gear 25 and transmit power on the servo motor 27 side.

The lower frame 11 has a shape in which the outer peripheral side surface that opens downward has a cylindrical shape. At the lower end of the lower frame 11, a bottom plate 51 is attached by bolts and is further sealed by the bottom plate 51. Lower frame 11
Lubricating oil is sealed inside so that power can be smoothly transmitted between both bevel gears 25 and 25a.

Further, as shown in FIG. 4, the bottom plate 51 is provided with an insertion hole 52a directed in the axial direction of the injection device 3 to the rotary shaft 2.
3 are provided at equal intervals on both sides of 8, and the insertion holes 52
A connecting rod 52 is arranged so as to pass through a. From the bevel gear 25, for example, 2 to 3 are attached to the upper end of the connecting rod 52.
The friction plates 30 are arranged at a distance of mm from each other and are integrally fixed by bolts, and the connecting rod 5
A plate 53 is arranged at the lower end of the plate 2 so as to be separated from the bottom plate 51, and is integrally fixed with a bolt.

On the innermost peripheral portion of the circular plate 53, recesses are provided at four equally spaced intervals, and springs 54 are mounted between the bottom plates 51. The bevel gear 25 and the friction plate 30 described above are continuously separated from each other by, for example, 2 to 3 mm by the extension force. Further, after the piston 44 is raised by the pressure oil and abuts against the plate 53, the plate 53 is raised by overcoming the extension force of the spring 54, and further the friction plate 30 is pushed up via the rod 52 to lift the bevel gear 25. The friction plate 3 is brought into contact with the end face.
The reverse rotation of the screw shaft 21 (downward movement of the ball holder 33) can be completely prevented by the friction between 0 and the bevel gear 25. Next, the valve (not shown) is switched to the piston 44.
When the pressure oil is removed, the extension force of the spring 54 restores the original state, that is, the friction plate 30 and the bevel gear 2.
The five are separated from each other.

A plurality of balls 32 are held in parallel in the spiral thread groove of the screw shaft 21, and the ball holder 33 fitted in the holder hole 18b of the support frame 18 and bolted is A ball 32 is held in a spiral ball groove fitted in the screw shaft 21 and formed in its inner hole. By doing so, when the screw shaft 21 rotates, the support frame 18 moves up and down while rolling the balls 32 in the ball grooves. A plunger 34 is connected to the center of the support frame 18 by a coupling 35 and stands upright.
It is inserted in the inner hole of the car.

Thus, the molten metal injected into the inner hole of the injection sleeve 17 is pushed by the plunger tip 34a as the plunger 34 rises and is injected into the cavity of the mold through the fixed sleeve. ing. Reference numeral 36 denotes a cover having a semicircular cross section, which is supported by a cover 37 fixed to the upper frame 10 and covers the screw shaft 21 together with the cover 37. The cover 36 integrally projects with the support frame 18 and extends upward along the sleeve frame 15. Is configured to. Also, in the center of the plunger 34,
Water cooling pipe 3 opening to the outer periphery of the docking cylinder 12
8 is provided so as to penetrate therethrough, and the hose attached to the opening is connected to the cooling pump.

Reference numeral 41 indicates the pressing means as a whole. In the present embodiment, for example, a pressing oil cylinder 41 is used as the pressing means, and is mounted on the base 70 so as to start operating when the injection device 3 reaches the injection position.
A cylinder hole 11a formed by closing the upper and lower sides of the cylinder 50 with a lid 42 and a cylinder hole 11a.
And a piston 44 that is fitted in the piston 44 so as to move back and forth, and is connected to a hydraulic device via a pipe and an oil passage 45 provided below the cylinder 50 that engages with the piston 44.

[0021] Further, between the upper end descent limit of the lower end lowermost and the piston 44 of the screw shaft 21, a gap of about 3mm indicated at t ₁ in FIG. 1 is formed. By doing this, when the plunger tip 34a rises and the molten metal is filled in the cavity, oil is sent below the piston 44 to raise the piston 44, and then, for example, about 5 mm rises after coming into contact with the screw shaft 21. The plunger 34 is raised via the support frame 18 to perform a feeder operation.

The reference numeral 49 indicates that since the screw shaft 21 is rotated by the rotation of the servomotor 27 via the bevel gears 25a, 25, and a lifting force is generated when the support frame 18 is moved upward, the lower frame 11 is also connected. Is a movement restricting cylinder that restricts lifting of the piston rod 49a by engaging the movement restricting cylinder 49 with the tip of the piston rod 49a abutting against the lower frame 11 to drive the power of the servomotor 27 to the bevel gear 25a, When the screw shaft 21 is rotated via 25, the lower frame 11 is prevented from being lifted up by the transmitted component force of the bevel gears 25a, 25.

The operation of the injection device configured as described above will be described. When the whole of the injection device 3 is pushed by the drive device in the paper spine direction in the figure, the injection device 3 moves to the pouring position while rolling the ball 6 of the linear guide 2 in the ball groove, so that the molten metal is injected into the injection sleeve 17. Pour. After pouring, the injection device 3 is moved so as to return to the position below the injection position.

Next, when oil is fed to the ram 12a of the docking cylinder 12, the elevating shaft 13 ascends while rolling the balls 6a of the linear ball bearings 36, 55, and 56, and the injection sleeve 17 integral with this. Rises and is joined to the fixed sleeve of the mold. At this time, the support frame 18 is pushed by the locking member 20 and ascends by the action of the ball screw device including the screw shaft 21, the ball 32, and the ball holder 33, and the plunger tip 34a maintains the same positional relationship as the injection sleeve 17. Rising bear rises. Therefore, the molten metal in the injection sleeve 17 does not spill.

Then, the motor 27 is started to start the bevel gear 25a.
When the screw shaft 21 is rotated via the bevel gear 25, the support frame 18 causes the balls 32 to roll in the screw groove by the action of the screw shaft 21, and the linear ball bearing 55
Is moved while moving along the elevating shaft 13, and the plunger 34 and the plunger tip 34a, which are integral with the same, are also moved up. If the mold cavity (not shown) is filled with the molten metal, the motor 27
Stop and apply the electromagnetic brake.

When the molten metal is completely filled in the cavity, the oil is sent to the lower side of the piston 44 of the feeder cylinder 41, and the piston 44 moves up to come into contact with the bottom plate 51 and raise, for example, about 8 mm. Chip 3
Ascending along with 4a, the molten metal in the cavity is compressed to raise the molten metal. During such an injection operation, the water cooling pipe 38
Since cold water is supplied to and circulated, the plunger 34 is cooled.

When the injection operation is completed, the injection product is cooled and solidified, the mold is opened, the piston 44 of the feeder cylinder 41 is retracted, and the motor 27 with the brake released is driven to support the frame through the ball screw device. 18 is retracted and the plunger tip 34a is retracted. Plunger tip 3
When the 4a and the support frame 18 retreat to a predetermined position,
The support frame 18 pushes the locking member 20, and thereafter,
The lifting shaft 13 and the injection sleeve 17 also move at the same time.
Then, the injection device 3 is moved to the pouring position, and one cycle is completed.

The movement of the injection device 3 to the pouring position is
Although it may be performed by tilting as in the conventional case, in the case of this device, the height of the entire device is considerably lower than that of a device equipped with a conventional hydraulic injection cylinder, the tilting angle becomes large, and the pouring amount is increased. Since it decreases, it is preferable to use the horizontal movement type as in the embodiment. In addition, although the present embodiment shows an example in which the present invention is applied to a vertical casting type die casting machine, it can be applied to a horizontal casting type die casting machine, and further, an injection molding machine for plastics. The same effect can be obtained by carrying out the same.

[0029]

As is apparent from the above description, according to the present invention, there is provided a rotation-linear transmission mechanism which is interposed between the motor and the supporting frame to transmit the motion, and a motor which is axially supported by the frame. One screw shaft that is driven to rotate, a ball holder of a ball screw device that is fitted to these screw shafts, and a support frame that supports these ball holders at their outer peripheral portions,
Further, a brake that is located below the screw shaft to stop the rotation of the screw shaft, a plunger supported at the center of the support frame, and a plunger tip that is attached to the support frame so as to be movable up and down. By providing an injection sleeve that fits the plunger tip into the inner hole so that it can move back and forth, it is less affected by the machining accuracy of the machine and the rotation of the screw shaft can be performed smoothly. In addition, the use of bevel gears in the rotation-linear transmission mechanism simplifies the structure and facilitates power transmission.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an injection device according to the present invention.

FIG. 2 is a partially enlarged detailed vertical sectional view of a lower region of the injection device.

FIG. 3 is a plan view of an injection device.

FIG. 4 is a perspective view seen from AA of FIG.

[Explanation of symbols]

 1 Frame 2 Linear Guide 3 Injection Device 10 Upper Frame 11 Lower Frame 12 Docking Cylinder 13 Lifting Shaft 17 Injection Sleeve 18 Support Frame 21 Screw Shaft 25, 25a Bevel Gear 27 Servo Motor 28 Rotation Shaft 30 Friction Plate 31 Electromagnetic Brake 34 Plunger 41 Pressing oil cylinder 44 Piston 49 Movement restriction cylinder 50 Cylinder 52 Connecting rod 53 Plate

Claims (1)

[Claims] 1. A rotation-linear transmission mechanism which is interposed between a motor and a support frame to transmit a motion, one screw shaft which is rotatably supported by the frame and driven by a motor, and these screw shafts. A ball holder for the fitted ball screw device,
A support frame that supports these ball holders on the outer periphery, a brake that is located below the screw shaft and that stops the rotation of the screw shaft, a plunger that is supported in the center of the support frame, An injection device comprising: an injection sleeve which is attached to a support frame so as to be able to move up and down;