Mold change device for injection molding machines

Abstract

To provide an inexpensive mold exchange device for an injection molding machine.SOLUTION: A mold exchange device for an injection molding machine of the present invention includes: an injection molding machine; a mold exchange carriage movably provided next to the injection molding machine; and a carriage control system that controls a stop position of the mold exchange carriage. In the mold exchange device for the injection molding machine, the mold exchange carriage is moved by an induction motor, and the carriage control system has a positioning block whose movement stopping is controlled by a servo motor, and a positioning cylinder that abuts against the positioning block to stop the movement of the mold exchange carriage.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a mold changing device for an injection molding machine. [Background technology]

[0002] A known mold changing device for an injection molding machine is described in Japanese Patent No. 5090812 (Patent Document 1). This mold changing device controls the position of a self-propelled mold changing cart through communication between the control device of the injection molding machine equipped with a second mold and the control device of the self-propelled mold changing cart. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5090812 Summary of the Invention [Problem to be solved by the invention]

[0004] The molds placed on the self-propelled mold change cart of the prior art are heavy, and the mold change cart that transports the molds also has a large weight of its own. Therefore, the cart, which has a large inertia, slows down as it approaches the side of the injection molding machine, and is controlled by a cart control system to reduce impact when stopping and ensure accuracy of the stopping position.

[0005] The positioning control of the self-propelled mold change carriage by this carriage control system is performed by a servo motor, and the device is very expensive.

[0006] Therefore, an object of the present invention is to provide a mold changing device that can control the position of a mold changing carriage at low cost. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides the following: In a mold changing device for an injection molding machine, the mold changing device comprises an injection molding machine, a mold changing carriage movably provided beside the injection molding machine, and a carriage control system for controlling the stopping position of the mold changing carriage, the mold changing carriage is moved by an induction motor, and the carriage control system comprises a positioning block whose movement and stopping are controlled by a servo motor, and a positioning cylinder that abuts against the positioning block to stop the movement of the mold changing carriage. [Effects of the Invention]

[0008] According to the present invention, the heavy mold change carriage is driven by an induction motor and the position of the positioning block is controlled by a servo motor, so the carriage control system can be made smaller and therefore cheaper than conventional systems. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 shows a first embodiment of the present invention and is a plan view of a mold changing device immediately after a mold is carried out from an injection molding machine. [Figure 2] FIG. 2 is a plan view of the mold immediately before it is loaded into the injection molding machine. [Figure 3] FIG. 3 is a side view of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line CC in FIG. [Figure 5] FIG. 5 is a view taken along the line AA in FIG. [Figure 6] FIG. 6 is a view taken along the line BB in FIG. [Figure 7] FIG. 7 is a plan view showing a second embodiment of the present invention. [Figure 8] FIG. 8 is a view taken along the line DD in FIG. [Figure 9] FIG. 9 is a side view of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 6 show a first embodiment of the present invention.

[0011] The mold exchange device for an injection molding machine includes an injection molding machine 1, a mold exchange carriage 2 that is freely movable next to the injection molding machine 1, and a carriage control system 3 that controls the stopping position of the mold exchange carriage 2.

[0012] The mold exchange carriage 2 is moved by an induction motor (not shown).

[0013] The carriage control system 3 includes a positioning block 5 whose movement and stopping are controlled by a servo motor 4, and a positioning cylinder 6 that abuts against the positioning block 5 to stop the movement of the mold exchange carriage 2.

[0014] The injection molding machine 1 is a second mold-equipped injection molding machine. This second mold-equipped injection molding machine 1 is almost the same as the one described in Patent Document 1, so a detailed description of its configuration will be omitted and only an outline will be given below.

[0015] The two-mold-equipped injection molding machine 1 (hereinafter simply referred to as the "injection molding machine") has a fixed platen 7, a movable platen 8, and a rotary platen 9 between them. A mold 11a is attached to the fixed platen 7 and the rotary platen 9, and a mold 11b is attached to the rotary platen 9 and the movable platen 8. In FIG. 1, the molds 11a and 11b have been removed and are placed on the mold exchange cart 2 as used molds, and replacement molds 11a and 11b to be carried in are placed on the mold exchange cart 2.

[0016] The mold exchange cart 2 is placed next to the injection molding machine 1. Two guide rails 12 are laid next to the injection molding machine 1. The mold exchange cart 2 has wheels 13 that run on the guide rails 12. These wheels 13 have drive wheels driven by an induction motor (not shown). On the top surface of the mold exchange cart 2, four sets of mold carriers equipped with rollers 14 that transport the molds to and from the injection molding machine 1 are provided. The mold exchange cart 2 is composed of an outgoing carrier 2a and an incoming carrier 2b on which the used molds 10a, b that have been transported from the injection molding machine 1 and the replacement molds 11a, b that will be transported thereto are placed.

[0017] An LM guide 15 (a registered trademark of THK) is provided between the two guide rails 12 and parallel to the guide rails 12 (see Figures 4 and 5). A positioning block 5 is movably provided on the LM guide 15. A nut 16a is provided on the positioning block 5, and a ball screw 16 is threadedly engaged with this nut 16a. The ball screw 16 is rotationally driven by the servo motor 4. The end of the ball screw 16 and the output shaft of the servo motor 4 are linked by a chain 17 or a belt.

[0018] As shown in Figure 5, the mold exchange cart 2 is provided with a positioning cylinder 6 that abuts against the positioning block 5 to stop the movement of the mold exchange cart 2. The positioning cylinder 6 has a stopper pin 18 that can move up and down. When the stopper pin 18 protrudes downward, it abuts against the side of the positioning block 5, stopping the movement of the mold exchange cart 2 and positioning it. When it moves upward, the stopper pin 18 does not abut against the positioning block 6, allowing the mold exchange cart 2 to move.

[0019] The positioning cylinders 6 are provided at two locations, one for the outgoing platform 2a and one for the incoming platform 2b.

[0020] A sensor (not shown) for detecting the positioning block is provided near the positioning cylinder 6. Upon detection by this sensor, the induction motor is controlled so that the movement of the mold exchange carriage 2 is decelerated and stopped.

[0021] An intermediate carriage 19 for carrying in and out molds is provided between the injection molding machine 1 and the mold exchange carriage 2. The intermediate carriage 19 has wheels 21 that run on rails 20 so that it can move parallel to the mold exchange carriage 2. The movement and stopping of the intermediate carriage 19 is controlled by a servo motor 4 for driving a positioning block (see FIG. 6). A nut 22 is provided on the intermediate carriage 19, and a ball screw 23 is threadedly engaged with this nut 22. The ball screw 23 is rotated by the servo motor 4.

[0022] Next, the operation of the carriage control system 3 during mold replacement will be described. During mold replacement, the mold replacement cart 2 loads the replacement molds 11a, b onto the loading platform 2a, and the unloading platform 2b is an empty platform prepared as a space to store the used molds. The mold replacement cart 2 is driven by an induction motor to move so that the unloading platform 2a is positioned at a predetermined position on the side of the injection molding machine 1. At this time, when a sensor detects the positioning block 5, it is controlled to decelerate and stop.

[0023] As shown in FIG. 5, the mold exchange carriage 2 is stopped at an accurate position by the stopper pin 18 of the positioning cylinder 6 of the mold exchange carriage 2 coming into contact with the positioning block 5.

[0024] The positioning control of the positioning block 5 is performed by controlling the servo motor 4 based on the mold platen position data of the injection molding machine 1, so that the mold exchange carriage 2 stops at an appropriate position.

[0025] After the discharge platform 2a of the mold exchange cart 2 stops at the correct position, the used molds 10a, 10b removed from the injection molding machine 1 are carried out onto the empty discharge platform 2a. This state is shown in Figure 1.

[0026] Thereafter, in order to carry the replacement molds 11a and 11b into the injection molding machine 1, the mold exchange carriage 2 is moved by the drive of the induction motor.

[0027] Prior to this, the position of the positioning block 5 is changed to a position for the replacement molds 11a and 11b. This position change is performed by controlling the servo motor 4 based on mold platen position data of the injection molding machine 1 so that the mold change cart 2 stops at an appropriate position.

[0028] After the position of the positioning block 5 has been changed, the mold change cart 2 is driven by the induction motor to move so that the loading platform 2b is positioned at a predetermined position on the side of the injection molding machine 1. When the sensor detects the positioning block 5, the cart slows down and stops.

[0029] The mold exchange carriage 2 is stopped at the correct position by the stopper pin 18 of the positioning cylinder 6 of the mold exchange carriage 2 abutting against the positioning block 5. This state is shown in FIG.

[0030] After the mold exchange carriage 2 has stopped at the correct position, the replacement molds 11 a and 11 b are carried into the injection molding machine 1 .

[0031] Thereafter, the stopper pin 18 of the positioning cylinder 6 is moved upward to release it from contact with the positioning block 5, and the induction motor is driven to move the mold exchange carriage 2 to the mold preparation warehouse.

[0032] When controlling the position of the positioning block 5, the position of the intermediate carriage 19 is also controlled by the servo motor 4 at the same time.

[0033] Conventionally, the intermediate carriage has been fixedly provided on the side of the injection molding machine, but in this embodiment, it can be positioned more accurately when changing molds.

[0034] According to the above embodiment, a small servo motor 4 is sufficient for position control of the positioning block 5, which can be a cheaper device than the large servo motors that drive the conventional heavy mold exchange carriages.

[0035] 7 to 9 show a second embodiment of the present invention. The difference from the first embodiment is that the positioning block 5 is connected to an intermediate carriage 19.

[0036] In the second embodiment, an LM guide 15 is disposed between the mold exchange carriage 2 and the intermediate carriage 19. This LM guide 15 is provided with a positioning block 5, and the position of the positioning block 5 is controlled by a servo motor 4, which is the same as in the first embodiment.

[0037] The positioning block 5 and the intermediate carriage 19 are connected via a connecting plate. The positioning cylinders 6 are provided at two locations on the side of the mold exchange carriage 2.

[0038] The effects of the second embodiment are the same as those of the first embodiment.

[0039] The present invention is not limited to the above-described embodiments. For example, the injection molding machine is not limited to a two-mold mounting type, but may be a two-material injection molding machine, a stack mold molding machine, or the like. The intermediate cart is not limited to a movable type. Furthermore, the protruding and recessed abutment relationship between the positioning block and the positioning cylinder may be reversed. The positional relationship between the outgoing platform and the incoming platform may also be reversed.

[0040] The scope of the present invention is defined by the claims, not by the above description, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0041] 1 injection molding machine 2 Mold change cart 2a Carrying platform 2b Loading platform 3. Bogie control system 4 servo motors 5 Positioning Block 6 Positioning cylinder 7 Fixed board 8 Movable mold board 9 Rotating platen 10a, b Used mold 11a,b Mold for renewal 12 Guide rail 13 wheels 14 Laura 15 LM guide 16 ball screw 16a nut 17 Chain 18 Stopper pin 19 Intermediate bogie 20 Rails (for intermediate carriages) 21 Wheels (for intermediate trucks) 22 Nut (for intermediate truck) 23 Ball screw (for intermediate carriage) 24 Blocks (connected with intermediate bogies)

Claims

[Claim 1] A mold changing device for an injection molding machine having an injection molding machine, a mold changing carriage provided movably beside the injection molding machine, and a carriage control system that controls the stopping position of the mold changing carriage, The mold change carriage is moved by an induction motor, The carriage control system is a mold exchange device of an injection molding machine having a positioning block whose movement and stopping are controlled by a servo motor, and a positioning cylinder that abuts against the positioning block to stop the movement of the mold exchange carriage.

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