JP2004284369A - Construction method for injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce costs by providing a plurality of kinds of machines with different injection speed capability while using respective rotation-linear movement converting mechanisms in common in an injection molding machine having a pair of the rotation-linear movement converting mechanisms in the injection mechanism. <P>SOLUTION: The construction method is for the injection molding machine provided with a pair of the rotation-linear movement converting mechanisms for converting the rotations of servo motors for injection to the linear movements respectively. It is selected whether driven pulleys, which are respectively connected to the rotating members of a pair of the rotation-linear movement converting mechanisms, are driven by a single servo motor for the injection or the respective driven pulleys are driven respectively and individually by a pair of the servo motors for the injection in accordance with the injection speed capability which is the injection speed specification required by the machine. And at the same time, a prescribed motor is selected from among the servo motors for the injection with different capacities. Further, a prescribed pulley is selected from among the driven pulleys with different diameters. As a result, the machine with the different injection speed capability can be constructed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for constructing an injection molding machine in which a screw in a heating cylinder is linearly driven by a plurality of rotary linear motion conversion mechanisms.

  When attempting to increase the size of an injection molding machine that uses an injection drive source (a screw forward / reverse drive source) as a servomotor, simply increasing the size of the injection servomotor in response to the increase in machine size (motor capacity) (By using a large servomotor), the outer diameter of the servomotor, the rotary linear motion conversion mechanism and the bearing increases, the moment of inertia increases, the transient response becomes poor, and the large capacity Since the servomotor is expensive, it causes a significant cost increase.

Therefore, by using two or more servomotors with relatively small capacity and low cost as the injection drive source, the power of multiple servomotors for injection is combined to obtain large power, and the cost increase is compared. There have been proposed various injection molding machines which achieve good transient response (good rise / fall characteristics) while suppressing the increase in moment of inertia. As described above, the prior art of an injection molding machine using two servo motors as an injection drive source is disclosed in, for example, Japanese Patent Publication No. 3-38100, Japanese Patent Application Laid-Open No. Sho 62-48520, and Japanese Patent Application Laid-Open No. Hei 1-247128. And Japanese Patent Application Laid-Open No. 4-47917.
Japanese Patent Publication No. 3-38100 JP-A-62-48520 JP-A-1-247128 JP-A-4-47917

  By the way, an injection molding machine is required to have machines of various injection speed specifications (injection speed capability) depending on the shape and material of a product to be molded. Conventionally, machines having different injection speed capabilities are provided for each model. The servomotor, the rotary linear motion conversion mechanism, the bearing for the rotary linear motion conversion mechanism, and the driven pulley that transmits the rotation of the servomotor to the rotary linear motion conversion mechanism are changed each time. For this reason, different parts must be prepared for each model having different injection speed capability, and there is a problem that when a machine with different injection speed capability is produced in a small quantity of many kinds, cost reduction becomes an obstacle.

  In view of such circumstances, the present invention provides, in an injection molding machine having an injection mechanism having a plurality of rotary linear motion conversion mechanisms, a plurality of types of machines having different injection speed capabilities while sharing each rotary linear motion conversion mechanism. The purpose is to reduce costs.

The present invention achieves the above-mentioned object,
An injection molding machine comprising a pair of rotary linear motion converting mechanisms for converting the rotation of the injection servomotor into linear motions, respectively, wherein the pair of rotary linear motion converting mechanisms linearly drives a screw in a heating cylinder. In a method of constructing an injection molding machine that is constructed as a plurality of types of machines each having a different specific injection speed capability,
The pair of rotary linear motion conversion mechanisms is prepared as a common component shared among a plurality of models described above,
The driven pulley connected to the rotating member of the rotary linear motion conversion mechanism, as a component for selection selected according to the plurality of models, a plurality of types of driven pulleys having different diameters are prepared,
The injection servomotor has a plurality of types of injection servomotors having different capacities prepared as selection components selected according to the plurality of models,
A pair of driven pulleys having a specific diameter selected from among the plurality of types are selected according to an injection speed capability that is an injection speed specification required for a machine. To each other,
The pair of driven pulleys may be driven by a single servomotor for injection, or the pair of driven pulleys may be driven by a pair of By selecting whether to drive individually with the servo motor, by mounting the injection servo motor having a specific capacity selected from the plurality of types in one or two machines,
Machines for each model having different injection speed capability can be constructed by selecting and combining the selecting component with respect to the common component.

  According to the present invention, in an injection molding machine having a plurality of rotary linear motion converting mechanisms in an injection mechanism, it is possible to provide a plurality of types of machines having different injection speed capabilities while sharing each rotary linear motion converting mechanism. Thus, cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional plan view of a main part showing a main part configuration of an injection system mechanism of an injection molding machine according to an embodiment of the present invention (hereinafter, referred to as the present embodiment).

  In FIG. 1, 1 and 2 are support blocks, 3 is a heating cylinder whose rear end is held by the support block 1, 4 is a screw disposed inside the heating cylinder 3 so as to rotate and move back and forth. Is a plurality (here, four) of guide bars provided between the support blocks 1 and 2.

  Reference numeral 6 denotes a slide body which is inserted into each guide bar 5 and is provided so as to be able to move forward and backward along the guide bar 5. The slide body 6 has a servomotor 7 for measurement for rotating and driving the screw 4. It is installed. Reference numeral 8 denotes a screw driving body that fixes and supports the rear end of the screw 4 and is rotatably held by a slide body 6 via a bearing (angular bearing) 9. Reference numeral 10 denotes a driven pulley for rotating the screw, which is fixed to the screw driver 8. Reference numeral 11 denotes a drive pulley fixed to the output shaft of the servomotor 7. A timing belt 12 is wound between the drive pulley 11 and the driven pulley 10, and the drive pulley 11 is driven by the servomotor 7 for measurement. The screw 4 is driven to rotate via a timing belt 12, a driven pulley 10, and a screw driver 8.

  13A and 13B are a pair of ball screw shafts rotatably held on the support block 2 via bearings (angular bearings) 14A and 14B. Nut bodies 15A and 15B are screwed on the ball screw shafts 13A and 13B, respectively. The driven pulleys 16A and 16B for forward and backward movement of the screw are fixed. As will be described later, the driven pulleys 16A and 16B are driven to rotate by a servomotor for injection (for forward and backward movement of the screw), whereby the ball screw shafts 13A and 13B are driven to rotate and the nut body is rotated. 15A and 15B are driven forward and backward. That is, the ball screw shaft 13A and the nut body 15A and the ball screw shaft 13B and the nut body 15B constitute a rotary linear motion converting mechanism for converting the rotary motion into a linear motion and moving the screw 4 back and forth.

  The driven pulleys 16A and 16B have different diameters according to the injection speed specification (injection speed capability) required for the machine, as described later, and have a diameter corresponding to the injection speed specification ( Here, the driven pulleys 16A-1, 16B-1, 16A-2, 16B-2, 16A-3, 16B-3, or 16A-4, 16B-4) are fixed to the ball screw shafts 13A, 13B. It has become so. The driven pulleys 16A and 16B are driven to rotate by a single injection servomotor as described later, or the driven pulleys 16A and 16B are individually driven by two injection pulleys 16A and 16B. In addition, two types of injection servomotors having different capacities are prepared here as injection servomotors, as will be described later.

  The front ends of the nuts 15A and 15B are fixed to connecting members 17 and 18 having through holes, respectively. The connecting members 17 and 18 are fixed to the rear end surface of the slide body 6, and Reference numeral 18 is disposed so as to be sandwiched between the end surfaces of the nut bodies 15A and 15B and the slide body 6. The two connectors 17 and 18 have the same outer dimensions, but one of the connectors 18 is configured as a pressure detector 18 having a load cell (not shown) as a pressure sensor. I have.

  With the above configuration, the linear motion of the nut bodies 15A, 15B linearly driven by the rotation of the ball screw shafts 13A, 13B causes the connecting body 17, the pressure detecting body (connecting body) 18, the slide body 6, and the bearing 9 to move. Via the screw drive 8 and the screw 4 integrated therewith. The pressure applied to the screw 4 is applied to the pressure detector 18 via the screw driver 8, the bearing 9, and the slide 6, thereby giving the injection pressure during the injection stroke and the screw 4 during the metering stroke. The back pressure is detected. Since the pressure from the screw 4 is applied to the pressure detector 18 by 体, the detection value of the pressure detector 18 is doubled in the pressure detection circuit system to reduce the injection pressure value and the back pressure value. Be recognized.

  Next, in the present embodiment, an example of constructing four types of machines having different injection speed capabilities will be described with reference to FIG. 2 (a) to 2 (d) are diagrams showing the positional relationship between various types of a pair of driven pulleys 16A and 16B for forward and backward movement of a screw and a corresponding servo motor for injection. (A) is a machine with an ultra-low speed specification, FIG. 2 (b) is a machine with a low speed specification, FIG. 2 (c) is a machine with a high speed specification, and FIG. Each is shown.

(1) Ultra-low-speed machine In FIG. 2A, reference numeral 19 denotes an injection servomotor having a capacity of 11 kW mounted on the support block 2, reference numeral 20 denotes a driving pulley fixed to an output shaft of the servomotor 19, and reference numeral 16A. Reference numerals -1 and 16B-1 denote driven pulleys having the largest diameters fixed to the ball screw shafts 13A and 13B. A timing belt 21 is provided between the driving pulley 20 and the pair of driven pulleys 16A-1 and 16B-1. , And the two driven pulleys 16 </ b> A- 1 and 16 </ b> B- 1 are rotationally driven by a single injection servomotor 19.
In the configuration shown in FIG. 2A, only one servo motor 19 for injection having a capacity of 11 KW, that is, a relatively small capacity is used. By using the driven pulleys 16A-1 and 16B-1 having the largest diameters, a sufficient reduction ratio is ensured. Therefore, the injection speed is the lowest and has a speed capability of, for example, about 100 mm / sec, and can be used, for example, for lens molding.

(2) Machine of low-speed specification In FIG. 2B, reference numeral 22 denotes a servomotor for injection having a capacity of 15 kW mounted on the support block 2, 23 denotes a driving pulley fixed to the output shaft of the servomotor 22, and 16A- Reference numerals 2, 16B-2 denote second-largest driven pulleys fixed to the ball screw shafts 13A, 13B. A timing belt is provided between the driving pulley 23 and the pair of driven pulleys 16A-2, 16B-2. 24, the two driven pulleys 16A-2 and 16B-2 are rotationally driven by a single injection servomotor 22.
In the configuration shown in FIG. 2B, an injection servomotor 22 having a capacity of 15 kW, that is, a capacity larger than the capacity of 11 kW is used, so that the configuration shown in FIG. Even when the driven pulleys 16A-2 and 16B-2 having a small diameter are used, the injection pressure can be sufficiently and sufficiently secured. Therefore, the reduction ratio is smaller than that in the case of FIG. 2A, and the injection speed is higher than that of the configuration of FIG. 2A. For example, the injection speed may be about 150 mm / sec. it can.

(3) High-speed specification machine In FIG. 2C, reference numerals 19 and 19 denote a pair of injection servomotors having a capacity of 11 kW mounted on the support block 2, and 20, 20 denote outputs of the servomotors 19 and 19, respectively. Drive pulleys fixed to the shafts, 16A-3 and 16B-3 are driven pulleys fixed to the ball screw shafts 13A and 13B, and the driven pulleys 16A-3 and 16B-3 are driven pulleys shown in FIG. The diameter is smaller than the pulleys 16A-2 and 16B-2. Timing belts 25 are wound between one driving pulley 20 and the driven pulley 16A-3 and between the other driving pulley 20 and the driven pulley 16B-3. The pulleys 16A-3 and 16B-3 are driven to rotate by a pair of corresponding servo motors 19 for injection.
In the configuration shown in FIG. 2C, the injection servomotors 19 and 19 are individually assigned to drive the driven pulleys 16A-3 and 16B-3. Even if the motor has a relatively small capacity (capacity: 11 kW), the injection pressure can be sufficiently increased even when the driven pulleys 16A-3 and 16B-3 having a smaller diameter than in the case of FIG. Can be secured. Therefore, the speed reduction ratio is smaller than that in the case of FIG. 2B, and the injection speed is higher than that of the configuration of FIG. 2B. For example, it is possible to have a speed capability of about 200 mm / sec. For example, it can be used for thin molding.

(4) Ultra-high-speed specification machine In FIG. 2D, 22 and 22 are a pair of injection servomotors with a capacity of 15 kW mounted on the support block 2, and 23 and 23 are the servomotors 22 and 22, respectively. Drive pulleys fixed to the output shaft, 16A-4 and 16B-4 are driven pulleys fixed to the ball screw shafts 13A and 13B, and the driven pulleys 16A-4 and 16B-4 have the smallest diameters. ing. Timing belts 26 are wound between one driving pulley 23 and the driven pulley 16A-4 and between the other driving pulley 23 and the driven pulley 16B-4, respectively. The pulleys 16 </ b> A- 4 and 16 </ b> B- 4 are respectively driven to rotate by a pair of corresponding servo motors 22 for injection.
In the configuration shown in FIG. 2D, a pair of injection servomotors 22 having a capacity of 15 kW, that is, having a large capacity as compared with the capacity of 11 kW is used, so that the configuration shown in FIG. Even if the driven pulleys 16A-4, 16B-4 having a smaller diameter than in the case are used, the injection pressure can be secured sufficiently. Therefore, the speed reduction ratio is smaller than in the case of FIG. 2C, and the injection speed is higher than that of the configuration of FIG. 2C. For example, the injection speed may be about 300 mm / sec. For example, it can be used for ultra-thin molding.

  As described above, in the present embodiment, it is possible to construct four types of machines having different injection speed capacities by sharing each rotary linear motion mechanism, and to produce parts having different injection speed capacities, Cost reduction can be achieved by sharing.

  In the above-described embodiment, the screw is moved forward and backward by a pair of rotation-linear motion converting mechanisms. It goes without saying that the invention is applicable.

FIG. 2 is a fragmentary plan view showing a configuration of a main part of an injection system mechanism of the injection molding machine according to one embodiment of the present invention. It is an explanatory view showing an example in the case of constructing four kinds of machines with different injection speed capability in the injection molding machine concerning one embodiment of the present invention.

Explanation of reference numerals

Reference numerals 1, 2 Support block 3 Heating cylinder 4 Screw 5 Guide bar 6 Slide body 7 Servo motor for measurement 8 Screw drive 9 Bearing 10 Driven pulley for screw rotation 11 Drive pulley 12 Timing belt 13A, 13B Ball screw shaft 14A, 14B Bearing 15A, 15B Nut body 16A, 16B (16A-1, 16B-1, 16A-2, 16B-2, 16A-3, 16B-3, 16A-4, 16B-4) Driven pulley 17 for screw forward and backward movement Body 18 Pressure detecting body (Connected body)
19,22 Servo motor for injection 20,23 Drive pulley 21,24,25,26 Timing belt

Claims (1)

An injection molding machine comprising a pair of rotary linear motion converting mechanisms for converting the rotation of the injection servomotor into linear motions, respectively, wherein the pair of rotary linear motion converting mechanisms linearly drives a screw in a heating cylinder. In a method of constructing an injection molding machine that is constructed as a plurality of types of machines each having a different specific injection speed capability,
The pair of rotary linear motion conversion mechanisms is prepared as a common component shared among a plurality of models described above,
The driven pulley connected to the rotating member of the rotary linear motion conversion mechanism, as a component for selection selected according to the plurality of models, a plurality of types of driven pulleys having different diameters are prepared,
The injection servomotor has a plurality of types of injection servomotors having different capacities prepared as selection components selected according to the plurality of models,
A pair of driven pulleys having a specific diameter selected from among the plurality of types are selected according to an injection speed capability that is an injection speed specification required for a machine. To each other,
The pair of driven pulleys may be driven by a single servomotor for injection, or the pair of driven pulleys may be driven by a pair of By selecting whether to drive individually with the servo motor, by mounting the injection servo motor having a specific capacity selected from the plurality of types in one or two machines,
A method for constructing an injection molding machine, wherein machines for each model having different injection speed capability can be constructed by selecting and combining the selecting component with respect to the common component.

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