JP2003071890A - Drive device for molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To amplify an output of a linear motor by adopting a small-sized reduction gear mechanism with a simple structure and to reduce in size an overall driver without damaging respective members by an inertial force at an accelerating or decelerating time. SOLUTION: The drive device for a molding machine comprises the linear motor 20 having an output shaft to reciprocate, a reduction gear mechanism output member for holding a rotor to be rotated in contact with a side face of the output shaft to reciprocate the output shaft, and a reduction gear mechanism having a stationary member brought into contact with an opposite side to the output shaft of the rotor.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, in a molding machine such as an injection molding machine, a resin heated and melted in a heating cylinder is injected at a high pressure to fill a cavity space of a mold device, The molded product is molded by cooling and solidifying the resin in the space.

To this end, the mold device is composed of a fixed mold and a movable mold, and the mold clamping device moves the movable mold forward and backward to bring the movable mold into and out of contact with the fixed mold to open and close the mold. , Mold closing, mold clamping and mold opening can be performed.

Further, when the mold device is clamped, the injection device is advanced and the nozzle of the heating cylinder is disposed on the back surface of the stationary mold through the nozzle passage hole formed in the stationary platen. The sprue bush is pressed against the sprue bush for close contact. Subsequently, the molten resin is injected under high pressure from the nozzle and is filled into the cavity space formed on the mating surface of the fixed mold and the movable mold through the sprue bush and the sprue. .

A hydraulic piston or a servomotor is usually adopted as a drive device for advancing and retracting the movable platen to which the movable mold is attached and the injection device, but the structure of the drive device is simplified. An injection molding machine using a linear motor has been proposed in order to improve work efficiency (JP-A-62-25022, JP-A-1).
1-58468, JP-A-11-309752, and JP-A-2001-124169).

FIG. 2 is a schematic view of a conventional injection molding machine.

In the figure, reference numeral 114 denotes a fixed platen to which a fixed mold 115a is attached, which is fixed on the frame 110. And 116 is a movable mold 115b.
Is a movable platen attached to and moves along the tie bar in the horizontal direction in the figure. Further, 117 is a fixed bracket to which a mold clamping linear motor 118 that moves the movable platen 116 forward and backward (moves in the left-right direction in the drawing) is attached, and is fixed on the frame 110.

Here, the mold clamping linear motor 118 is used.
Is the stator 118b fixed to the right side surface of the fixing bracket 117 in the drawing, and one end thereof is directly or
The linear rotor 118a is connected to the left side surface of the movable platen 116 in the figure via a connecting member. The linear rotor 118a is the fixed bracket 1
The movable platen 116 is inserted into the through hole for the rotor formed in 17 and moved in the left-right direction in the drawing to move the movable platen 116 to perform mold closing, mold clamping and mold opening.

On the right side of the fixed platen 114 in the drawing, a moving bracket 112 is attached to the frame 110.
It is attached so as to be movable in the left and right directions above. An injection device 125 is attached to the moving bracket 112. Here, the injection device 125 includes a heating cylinder 124, and a screw 1 arranged in the heating cylinder 124 so as to be rotatable and movable in the left-right direction.
11, a nozzle 122 formed at the tip of the heating cylinder 124, a hopper 123 for feeding the raw material resin into the heating cylinder 124, and the like, the raw material resin is heated and melted, and is ejected from the nozzle 122. ing.

A linear motor 119 for moving the bracket is provided at the left end of the moving bracket 112 in the figure.
Is attached. Here, the linear motor 119 for moving the bracket is connected to a stator 119b fixed to a cylindrical mounting member attached to the left end of the moving bracket 112 in the drawing, and one end thereof is directly or through a connecting member. The fixed platen 114 includes a linear rotor 119a connected to the right side surface of the figure. The linear rotor 119a is inserted into the cylindrical mounting member, moves in the left-right direction in the drawing to move the moving bracket 112, and the nozzle 122 of the heating cylinder 124 is moved.
Is pressed against the back surface of the fixed mold 115a.

The screw shaft extending to the right in the drawing of the screw 111 is inserted into the screw shaft insertion hole of the moving bracket 112. On the left side of the screw shaft insertion hole, the stator 113b of the rotary motor 113 for rotating the screw shaft is attached to the moving bracket 112, and the rotor 113a of the rotary motor 113 is integrally formed on the outer periphery of the screw shaft. To be done. Further, on the right side of the screw shaft insertion hole, the stator 120b of the screw linear motor 120 for axially moving the screw shaft is attached to the moving bracket 112, and the screw linear motor 120 is attached to the outer periphery of the screw shaft. The rotor 120a is integrally formed.

Then, the screw 111 is rotated by the rotary motor 113 to knead and melt the resin in the heating cylinder 124. In addition, the screw linear motor 1
The screw 111 is moved to the left in the figure by 20, and the molten resin in the heating cylinder 124 is injected from the nozzle 122 at high pressure, and the fixed mold 115
The cavity is formed in the mating surface between the a and the movable mold 115b.

As described above, the movable platen 116, the movable bracket 112, and the screw 111 are moved forward and backward by a linear motor 118 for clamping, which is a linear motor.
Since the linear motor 119 for moving the bracket and the linear motor 120 for the screw are respectively used, the movable part of the injection molding machine can be directly driven, the driving device can be simplified, and the operation is delayed. Since it does not occur, work efficiency is improved.

[0014]

However, in the drive unit of the conventional injection molding machine described above, the movable platen 116, the movable bracket 112 and the screw 111, which are the driven members, are directly moved forward and backward by the linear motor. Therefore, the speed reducing mechanism for amplifying the output is not provided.

For this reason, the linear motor as the drive source needs to generate a large output, and therefore becomes large in size. However, if the linear motor itself becomes large, the entire driving device also becomes large, and the advantage of the linear motor that the driving device can be simplified is lost.

Further, when a speed reducing mechanism is adopted, a mechanism for decelerating the linear motion by the linear motor to amplify the output is
Usually, it becomes complicated and large like a toggle link mechanism. Therefore, if such a reduction mechanism is adopted, the advantage of the linear motor that the drive device can be simplified is lost.

Further, in a drive device that linearly moves a movable member using a linear motor, a large inertial force due to the linear motion acts on each part of the drive device during acceleration / deceleration, so that each part of the drive device and the movable member. May be damaged.

The present invention solves the above-mentioned problems of the drive unit of the conventional molding machine, adopts a small speed reducing mechanism having a simple structure, and can amplify the output of the linear motor. An object of the present invention is to provide a driving device for a molding machine, which can reduce the size of the entire driving device without damaging each member due to inertial force during deceleration.

[0019]

To this end, in the driving apparatus for a molding machine of the present invention, a linear motor having an output shaft that reciprocates and a rotating body that is rotated by contacting the side surface of the output shaft are held. And reciprocating speed reduction mechanism output member,
And a speed reduction mechanism including a fixing member that contacts the opposite side of the rotating body from the output shaft.

In another driving apparatus for a molding machine of the present invention, the rotating body is a gear and meshes with the rack teeth formed on the side surface of the output shaft and the fixed member.

In still another driving apparatus for a molding machine of the present invention, the rotating body is a roller and transmits a force between the side surface of the output shaft and the fixed member by traction.

In yet another molding machine driving device of the present invention, the reduction mechanism is further connected in a plurality of stages to reduce the output of the linear motor in a plurality of stages.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drive device of the present invention can be applied to various devices and applications, but in the present embodiment, for convenience of explanation, a case where it is applied to an injection molding machine will be described.

FIG. 1 is a side sectional view of an injection device and a driving device of an injection molding machine according to an embodiment of the present invention. FIG. 3 is a side sectional view of a driving device of an injection molding machine according to the embodiment of the present invention. FIG. 4 is a plan sectional view of a drive device of an injection molding machine according to an embodiment of the present invention, a sectional view taken along the arrow A in FIG. 3, and FIG. 5 is a sectional view taken along the arrow B of FIG. 3 according to the embodiment of the present invention.

In FIG. 1, 30 is a plunger portion in the injection device, 31 is a plunger cylinder, 32 is a plunger arranged in the plunger cylinder 31 so as to be reciprocable in the left-right direction in the figure, and 33 is the plunger 32. Nozzle attached to the left end in the figure, 34 is formed in the nozzle 33,
It is a resin flow path communicating with the inside of 1. The nozzle 33
It is desirable to dispose an opening / closing valve for opening / closing the flow path in the resin flow path 34 at the tip portion of the.

Reference numeral 35 is a plasticizing section in the injection device, 36 is a heating cylinder, and 37 is the heating cylinder 3.
A screw 38, which is rotatably disposed in 6, is a resin flow passage communicating with the inside of the thermal cylinder 36 and the resin flow passage 34. It is desirable that an on-off valve that opens and closes the flow passage is provided in the resin flow passage 38.

In the present embodiment, the injection device is a pre-plunger injection device, and the plasticizing section 35 and the plunger section 30 are separately configured, and the resin is heated and melted in the plasticizing section 35. A plasticizing step is performed, and an injection step of the resin melted in the plunger portion 30 is performed. By the way, a screw in-line type injection device in which an injection device is subjected to a plasticizing step of heating and melting resin by rotating a screw, and subsequently an injection step of resin is performed by reciprocating of the screw. However, for convenience of explanation, only the drive device in the pre-plunger injection device will be described in the present embodiment. The drive device 10 of the injection molding machine according to the present embodiment can be applied not only to the pre-plunger type injection device but also to a screw in-line type and other injection devices.

Here, the driving device 10 has a linear motor 20 attached to a motor support bracket 22 fixed on a driving device frame 25. The linear motor 20 includes a stator 21 attached to an inner periphery of a through hole for a linear motor formed in the motor support bracket 22, and a rotor that moves in a space sandwiched by the stator 21 in the left-right direction in the drawing. And a moving rod 11 as an output shaft that functions as Here, as shown in FIG. 5, the moving rod 11 is a quadrangular prismatic member having a rectangular cross section and extending in the left-right direction in FIG.

The structure of the linear motor 20 is as follows.
It may have any structure as long as it has a structure as a normal linear motor. In the present embodiment, for example, the moving rod 11 is provided on the surface of the portion of the moving rod 11 that functions as a rotor.
A large number of magnetic bodies are arranged at regular intervals in the lengthwise direction, and each of them acts as a magnetic pole portion. Here, the portion of the moving rod 11 that functions as a rotor is in the range of about the right half of FIGS. On the surface of the stator 21 facing the moving rod 11, a large number of coils are arranged at regular intervals in the length direction of the moving rod 11, and the coils generate magnetic fields having different phases. As a result, the moving rod 11 is moved to the position shown in FIG.
At the left and right.

The magnetic body of the moving rod 11 in the shape of a quadrangular prism may be arranged on any one of the four side surfaces, but in the present embodiment, it is arranged on all of the four side surfaces. The case where it is done is explained. The coils of the stator 21 are also arranged so as to face all four side surfaces of the moving rod 11 having a rectangular prism shape. Therefore, the stator 21 has a tubular shape with a square cross section as a whole.

Rack teeth 12 are formed on the upper and lower surfaces of the moving rod 11 in FIGS. Thereby, the moving rod 11 functions as a rack. The rack teeth 12 are arranged on the moving rod 11
When the movable rod 11 moves in the left-right direction in the drawing, the pinion gears 13 are rotated by meshing with a plurality of, for example, upper and lower three pinion gears 13 as rotating bodies. There is.

Here, as shown in FIG. 4, the pinion gear 13 is rotatably held by a gear holding portion 16a of a moving housing 16 as a reduction mechanism output member via a bearing 17. The moving housing 1
Reference numeral 6 denotes the gear holding portion 16a that rotatably holds the pinion gear 13 via a bearing 17, a guide portion 16b having a guide rod insertion hole (not shown) into which the guide rod 23 is inserted, and the plunger 32. A driving force transmission unit 16c that moves in the left-right direction is provided. The movable housing 16 is connected to the guide rod 23.
It is designed to move in the left-right direction in the figure. As a result, the plunger 32 attached to the driving force transmission portion 16c via the attachment member 18 is moved in the left-right direction in the drawing.

The guide rods 23 are plural, for example, four, and one end thereof is the motor support bracket 2
2 and the other end is fixed to a cylinder support bracket 24 for supporting the plunger cylinder 31 fixed on the drive device frame 25.

Further, the pinion gear 13 shown in FIGS.
Above and below the fixed rack member 1 as a fixing member.
4 are provided. The upper and lower fixed rack members 14 are fixed to the motor support bracket 22, and rack teeth 15 are formed on the surfaces facing each other, and the rack teeth 15 mesh with the pinion gear 13. Then, a moving rod 11 having the rack teeth 12 formed thereon, a moving housing 16 holding the pinion gear 13, and
The fixed rack member 14 having the rack teeth 15 forms a differential mechanism that functions as a speed reduction mechanism.

In the present embodiment, the moving rod 11 is integrally formed, and the portion functioning as the rotor and the portion where the rack teeth 12 are formed partially overlap. Thereby, the length of the moving rod 11 can be shortened, and the length of the entire driving device 10 can be shortened. The moving rod 11 does not have to be integrally configured, and, for example, a portion functioning as a rotor and a portion on which the rack teeth 12 are formed may be separately formed and connected to each other. . In this case, the moving rod 11 is long, but the manufacturing is easy.

Next, the operation of the injection device and the drive device having the above-mentioned construction will be described.

First, in the plasticizing section 35, the screw 3
7 is rotated to knead and melt the resin in the heating cylinder 36, and the molten resin is supplied into the plunger cylinder 31 through the resin flow passage 38 and the resin flow passage 34. in this case,
It is desirable to close an on-off valve (not shown) provided in the resin flow path 34 so that the molten resin does not leak out from the tip of the nozzle 33.

Next, when the plunger cylinder 31 is filled with the molten resin, the tip of the nozzle 33 is pressed against the back surface of a fixed mold (not shown) by a driving device (not shown). In this case, it is desirable to open the open / close valve provided in the resin flow path 34 and close the open / close valve provided in the resin flow path 38. When the plunger cylinder 31 is filled with the molten resin, the plunger 32 is in the most retracted position, that is, the most rightward position in the drawing, as shown in FIG.

Next, the linear motor 20 is operated to move the moving rod 11 forward, that is, to move it to the left in the figure. The moving rod 11 is in the most retracted position in the state shown in FIG. 1 and is advanced from this position.

Here, the rack teeth 1 of the moving rod 11
Since 2 and the pinion gear 13 mesh with each other, when the moving rod 11 moves, the pinion gear 13 rotates. On the other hand, the pinion gear 13 meshes with the rack teeth 15 of the immovable fixed rack member 14 on the side opposite to the moving rod 11. Therefore, the pinion gear 13 moves by rotating. In this case, the pinion gear 13 moves in the same direction as the moving rod 11 and at a speed half that of the moving rod 11. Therefore, the moving housing 16 that holds the pinion gear 13 rotatably has the same structure as that of the moving rod 11.
Move forward at a speed of / 2.

The plunger 32 attached to the driving force transmitting portion 16c of the moving housing 16 via the attaching member 18 is moved forward at a speed half that of the moving rod 11. Thereby, the molten resin filled in the plunger cylinder 31 passes through the resin flow path 34,
It is injected from the tip of the nozzle 33 and is filled in the cavity space formed in the mating surface of the fixed mold and the movable mold (not shown).

As described above, the speed of the moving rod 11 is reduced to 1/2 by the actuating mechanism and transmitted to the moving housing 16 and the plunger 32.
The output of 1 is amplified twice and transmitted to the moving housing 16 and the plunger 32 (note that the loss due to frictional resistance is not taken into consideration).

Subsequently, as shown in FIG. 3, when the plunger 32 approaches the left end of the plunger cylinder 31 in the drawing, the linear motor 20 stops operating, so that the plunger 32 also stops. As a result, the injection of the molten resin from the tip of the nozzle 33 is also stopped.

When the plunger cylinder 31 is filled with the molten resin from the plasticizing portion 35, the linear motor 20 is operated to retract the moving rod 11,
The plunger 32 is retracted and returned to the position shown in FIG.

As described above, in the present embodiment, the moving rod 11 that functions as the rotor of the linear motor 20.
Of the moving housing 16 and the plunger 32 attached to the moving housing 16 by the operating mechanism.
Is moved forward at half the speed of the moving rod 11 and at twice the output of the moving rod 11.

Therefore, since the linear motion of the linear motor can be decelerated and the output can be amplified by the small-sized actuating mechanism having an extremely simple structure, the entire driving device 10 can be downsized and the output can be increased. Therefore, the plunger 32 can be quickly reciprocated, and the manufacturing cost and maintenance cost of the drive device 10 can be reduced.

In the present embodiment, the degree of deceleration is 1/2, but it is possible to further reduce the speed if necessary by connecting the actuating mechanisms in a plurality of stages. For example, if a rack tooth is formed on the outer side of the movable housing 16 and a further pinion gear meshing with the rack tooth is provided to form another operating mechanism, the operating mechanism further reduces
Since the speed is reduced to / 2, the speed is reduced to 1/4 as a whole. In this case, the plunger 32 is advanced with an output four times that of the moving rod 11.

Further, in the present embodiment, the actuating mechanism transmits the force by the pinion gear 13 meshing with the rack tooth 12 and the rack tooth 15, but the force may be transmitted by traction. it can. For example, the moving rod 11 and the fixed rack member 1
The surface on which the rack teeth 12 and the rack teeth 15 of 4 are formed is a flat surface (a curved surface when the moving rod 11 and the fixed rack member 14 are a cylinder or a cylinder), and a roller is used instead of the pinion gear 13. use. In this case, when the moving rod 11 moves forward, the roller rotates and rolls on the surface of the fixed rack member 14, so that the moving housing 16 moves at half the speed of the moving rod 11 and the moving rod 1 moves.
It can be advanced with twice the power of one.

Further, in this case, since the force is transmitted by the traction, it is possible to prevent the member from being damaged by slipping when a force exceeding the design value is applied to each member. For example, when the linear motor 20 is operated to start the forward movement of the plunger 32, or when the plunger 32 is stopped,
When a large force is applied to the members constituting the driving device 10 by the inertial force, the surface of the roller and the moving rod 11
Or, slip occurs between the surface of the fixed rack 14 and the surface.
For this reason, a force that is equal to or greater than the design value is not applied to the members that form the driving device 10, and thus the members are not damaged.

The drive device 10 of the injection molding machine according to the present embodiment can be applied not only to the pre-plunger type injection device but also to a screw in-line type injection device and the like. For example, when applied to a screw-in-line type injection device, instead of the plunger 32,
While attaching the screw to the moving housing 16,
A rotary motor having the same configuration as the rotary motor 113 in the injection molding machine shown in FIG. 2 described in "Prior Art" is adopted to rotate the moving rod 11 or directly rotate the screw. This allows the screw to reciprocate and rotate.

Further, the drive unit 10 can be used to advance and retract other members of the injection molding machine. For example, the mold clamping linear motor 118 in the injection molding machine shown in FIG. 2 described in “Prior Art”.
Alternatively, instead of the linear motor 119 for moving the bracket, the drive device 10 can be adopted. This allows
The movable platen of the injection molding machine can be reciprocated, and the injection device can be reciprocated.

In the above embodiment, the horizontal plate type injection molding machine in which the movable platen moves in the horizontal direction (horizontal direction) has been described. However, in the drive unit of the present invention, the movable platen is in the vertical direction (vertical direction). ) Can be applied to a vertical injection molding machine. In addition to the injection molding machine, the drive unit of the present invention is also equipped with a die cast machine, I
It can also be applied to a molding machine such as a J-sealing press.

The present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention, and they are not excluded from the scope of the present invention.

[0054]

As described above in detail, according to the present invention, in the driving device of the molding machine, the linear motor having the reciprocating output shaft and the side surface of the output shaft are contacted and rotated. It has a reduction mechanism output member that holds the rotating body and reciprocates, and a reduction mechanism that includes a fixing member that contacts the opposite side of the rotating body to the output shaft.

In this case, the output of the linear motor can be amplified by the small speed reducing mechanism having a simple structure, and the entire driving device can be downsized.

In another driving apparatus for a molding machine, the rotating body is a gear and meshes with rack teeth formed on the side surface of the output shaft and the fixed member.

In this case, the output of the linear motor is amplified and output without loss.

In still another driving apparatus for a molding machine, the rotating body is a roller, and the force is transmitted between the side surface of the output shaft and the fixed member by traction.

In this case, when a force exceeding the design value is applied to each member, the members can be prevented from being damaged by slipping.

In still another molding machine driving apparatus, the reduction mechanism is further connected in a plurality of stages to reduce the output of the linear motor by a plurality of stages.

In this case, the output of the linear motor can be amplified at any stage as needed.

[Brief description of drawings]

FIG. 1 is a side sectional view of an injection device and a drive device of an injection molding machine according to an embodiment of the present invention.

FIG. 2 is a schematic view of a conventional injection molding machine.

FIG. 3 is a side sectional view of a drive unit of the injection molding machine according to the embodiment of the present invention.

FIG. 4 is a plan sectional view of a drive unit of the injection molding machine according to the embodiment of the present invention, which is a sectional view taken along arrow A in FIG.

FIG. 5 is a sectional view taken along the arrow B of FIG. 3 in the embodiment of the present invention.

[Explanation of symbols]

10 Drive 11 Moving rod 12, 15 rack teeth 13 pinion gears 14 Fixed rack member 16 Moving housing 20 linear motor

Claims (4)

[Claims] 1. A linear motor having an output shaft that reciprocates, and (b) a reduction mechanism output member that reciprocates by holding a rotating body that is rotated by contacting a side surface of the output shaft.
And a speed reducing mechanism including a fixing member that contacts the opposite side of the rotating body from the output shaft. 2. The driving device for a molding machine according to claim 1, wherein the rotating body is a gear and meshes with rack teeth formed on a side surface of the output shaft and a fixed member. 3. The driving device for a molding machine according to claim 1, wherein the rotating body is a roller, and the force is transmitted between the side surface of the output shaft and the fixed member by traction. 4. The driving device for a molding machine according to claim 1, wherein the reduction mechanism is connected in a plurality of stages to reduce the output of the linear motor in a plurality of stages.