JP7779461B2 - Mold transport device - Google Patents

Description

The present invention relates to a device for replacing molds used in, for example, injection molding machines.

An injection molding machine is equipped with a set of molds to mold molten resin material into a molded product of a predetermined shape. One of the molds in the set is called the fixed mold because it is attached to a fixed platen that is fixed in position in the injection molding machine, and the other mold in the set is called the movable mold because it is attached to a movable platen that moves back and forth relative to the fixed platen. In an injection molding machine, the fixed mold and movable mold are used depending on the molded product to be produced. Therefore, the fixed mold and movable mold must be changed depending on the molded product.

In contrast to previous replacement methods in which dies placed on free-wheeling rollers were manually transported, Patent Document 1 proposes providing multiple sprockets rotated by a rotary drive means, as well as a rack member driven by the sprockets, which is attached near the bottom end of the die. In the die transport device of Patent Document 1, when the rotary drive means is operated, the sprockets rotate to transport the die placed on the sprockets, and the rack member operates to transport the rack member and die together. Patent Document 1 claims that because the die is moved by the rotary drive means, the die movement speed can be increased, the accuracy of the die stopping position can be improved, and the time required for die replacement can be shortened.

Japanese Patent Application Laid-Open No. 2019-051601

The molds used in injection molding machines come in a wide variety of sizes, ranging from short to tall. "Tall" here refers to the vertical dimension (V). When subjected to a force in the horizontal direction (H) due to transport, a tall mold will be more unstable than a short mold.

In the mold conveying device of Patent Document 1, the conveying drive force is transmitted only to the bottom surface (lower surface) of the mold that contacts the sprocket and to the vicinity of the lower end of the mold where the rack member is engaged. When the conveying drive force is applied to the bottom surface of the mold in the horizontal direction (H), this drive force acts as a moment against the center of gravity of the mold. In particular, when a large drive force is applied to the lower part of the mold in an attempt to convey the mold at high speed, the moment acting on a tall mold is also large. In particular, immediately after applying the conveying drive force and accelerating the mold, the front end surface of the mold in the conveying direction may lift off the sprocket. Conversely, immediately after applying the conveying braking force and decelerating the mold, the rear end surface of the mold in the conveying direction may lift off the sprocket. The lifting stops, but a collision noise is generated when the bottom surface of the lifted mold lands on the sprocket. Furthermore, if the mold lifts, the lower part of the front or rear end lifts, causing the mold to disengage from the sprocket, resulting in poor transmission of the conveying drive force and preventing the desired mold conveying speed from being achieved.

Based on the above, the present invention aims to provide a mold transport device that enables stable, high-speed transport by preventing the front end of the mold from lifting up in the transport direction during acceleration or the rear end of the mold from lifting up in the transport direction during deceleration, even for tall molds.

The mold conveying device of the present invention conveys at least one set of molds, which is a combination of a fixed mold and a movable mold, along a conveying direction.
The mold conveying device includes a first conveying mechanism that conveys the mold in the conveying direction while placing the mold via the bottom surface, and a second conveying mechanism that conveys the mold in the conveying direction while applying a second driving force to a position vertically spaced from the bottom surface of the mold.
The mold transport device drives the first transport mechanism and the second transport mechanism simultaneously to transport the mold.

In the mold conveying device of the present invention, the preferred first conveying mechanism comprises a drive mechanism equipped with multiple rotating bodies aligned in the conveying direction and on which molds can be placed, and the preferred second conveying mechanism comprises a chain drive mechanism or a fluid pressure cylinder drive mechanism.

In the mold conveying device of the present invention, the first electric motor that is the drive source for the first conveying mechanism and the second electric motor that is the drive source for the second conveying mechanism are preferably electrically or mechanically synchronized.

In the mold conveying device of the present invention, the preferred second conveying mechanism conveys the mold while applying a load in a direction opposite to the moment that may occur in the mold when conveying by the first conveying mechanism is accelerating or decelerating.

In the mold conveying device of the present invention, during acceleration, the first-first driving force P11 and the second-first driving force P21 of the mold by the second conveying mechanism preferably have a relationship of P11 > P21. Furthermore, during deceleration, the first-second driving force P12 of the mold by the first conveying mechanism and the second-second driving force P22 of the mold by the second conveying mechanism preferably have a relationship of P12 ≦ P22.

The mold conveying device of the present invention provides a second conveying mechanism in addition to the first conveying mechanism, thereby preventing the front end of the mold from lifting up in the conveying direction during acceleration or the rear end of the mold from lifting up in the conveying direction during deceleration, even for tall molds, enabling stable, high-speed conveying.

FIG. 2 is a side view showing the mold transport device according to the first embodiment. FIG. 1 is a plan view showing a mold transport device according to a first embodiment. 10A to 10C are side views showing a process of transporting a mold by the mold transport device according to the first embodiment. 10A to 10C are plan views showing a process of transporting a mold by the mold transport device according to the first embodiment. 1A and 1B are diagrams illustrating the effect of the mold conveying device of the first embodiment, in which (a) shows a short mold, (b) shows a tall mold, and (c) shows a tall mold receiving a load from the second conveying mechanism. FIG. 10 is a side view showing a mold transport device according to a second embodiment. FIG. 10 is a plan view showing a mold transport device according to a second embodiment.

Below, two preferred embodiments of the present invention, a first embodiment and a second embodiment, will be described with reference to the accompanying drawings. The first and second embodiments are equipped with two transport mechanisms, a first transport mechanism and a second transport mechanism, for transporting molds, which prevents even tall molds from lifting at the front end (front surface FS) or rear end (back surface BS) in the transport direction, enabling stable and high-speed transport. Furthermore, while the first and second embodiments share the same configuration for the first transport mechanism, the second transport mechanism has a different configuration. Below, the first and second embodiments will be described in that order.

[First embodiment: Figures 1, 2, 3, and 4]
A mold conveying device 1A according to a first embodiment will be described with reference to FIGS.
The mold transport device 1A transports a mold DE to be newly used for injection molding, which has been transported from, for example, a storage facility to the mold DE load-in/load-out position 19, toward the mold placement area 117. The mold DE transported to the mold placement area 117 is attached to the fixed mold platen 111 and the movable mold platen 113 and waits for injection molding. When the mold DE is transported out of the mold placement area 117, the transport is performed in the reverse order of the above-mentioned load-in procedure.
The mold DE is made up of a set of a fixed mold DE1 and a movable mold DE2. When there is no need to distinguish between the fixed mold DE1 and the movable mold DE2, they are collectively referred to as the mold DE.

The basic functions of the mold conveying device 1A are as described above. The mold conveying device 1A also includes a first conveying mechanism 20 that applies a conveying drive force (hereinafter sometimes simply referred to as drive force) to the bottom surface of the mold, and a second conveying mechanism 40A that applies a load to the back surface of the mold. Below, we will provide an overview of the injection molding machine 100, followed by a detailed description of the mold conveying device 1A.

[Injection molding machine 100]
The main components of the injection molding machine 100 to which the mold conveying device 1A is applied will be described.
The injection molding machine 100 includes a mold clamping device 110 and an injection device 120 .
The mold clamping unit 110 includes a fixed platen 111 to which the fixed mold DE1 is attached and a movable platen 113 to which the movable mold DE2 is attached. A cavity corresponding to the molded product is formed between the fixed mold DE1 attached to the fixed platen 111 and the movable mold DE2 attached to the movable platen 113, and a molded product is obtained by injecting molten resin into this cavity from an injection unit 120. In order to apply a mold clamping force between the fixed mold DE1 and the movable mold DE2 during injection molding, the mold clamping unit 110 includes a plurality of tie bars 115 that penetrate the fixed platen 111 and the movable platen 113, and a drive source such as a hydraulic cylinder (not shown). A mold placement area 117 is defined between the fixed platen 111 and the movable platen 113, where the fixed mold DE1 and the movable mold DE2 are placed and fixed. In this embodiment, the mold DE is exemplified as a set of molds DE consisting of a fixed mold DE1 and a movable mold DE2, but in order to perform molding using multiple cavities or multiple molds, such as so-called family molding, multiple sets of molds DE consisting of fixed molds DE1 and movable molds DE2 may be attached to the fixed mold platen 111 and the movable mold platen 113.

The injection device 120 includes a heating cylinder 121 that heats and melts solid resin raw material, and an injection nozzle 123 that dispenses the molten resin material obtained by the heating cylinder 121 toward the cavity between the fixed mold DE1 and the movable mold DE2. A screw (not shown) is provided inside the heating cylinder 121 for kneading and melting the supplied resin raw material. A heater is also provided around the heating cylinder 121 for heating the resin raw material supplied inside. By heating the resin raw material with the heater and rotating the screw, the solid resin raw material is melted inside the heating cylinder 121 for use in injection molding. The mold conveying device 1A is not limited to injection molding machines 100, but can also be used in casting equipment such as die casting, which requires the replacement of heavy molds, and extrusion presses.

[Overall configuration of mold conveying device 1A: Figures 1 and 2]
1 and 2, the mold conveying device 1A includes a conveying table 10 on which a mold DE is conveyed from a carry-in/carry-out position 19 of the conveying table 10 toward a mold placement area 117 of an injection molding machine 100, or from the mold placement area 117 toward the carry-in/carry-out position 19. The mold conveying device 1A also includes a first conveying mechanism 20 that applies a driving force in a conveying direction X to convey the mold DE while placing it via the bottom surface SS of the conveying table 10. The mold conveying device 1A also includes a second conveying mechanism 40A that applies a driving force in the conveying direction X to convey the mold DE at a position spaced apart from the bottom surface SS of the mold DE in the vertical direction V (the direction opposite to the direction of gravity). When there is no need to distinguish between the fixed mold DE1 and the movable mold DE2, both will be collectively referred to as the mold DE.
1 and 2, the mold conveying device 1A is defined as having a conveying direction X, a width direction Y, and a height direction Z. In this embodiment, "direction" is a general term that includes two directions. For example, the conveying direction X includes the direction (X1) from the loading/unloading position 19 to the mold placement area 117 and the direction (X2) from the mold placement area 117 to the loading/unloading position 19.

[Transport table 10: Figures 1 and 2]
The conveying table 10 includes a first conveying mechanism 20 and a second conveying mechanism 40A. The mold conveying device 1A conveys the mold DE on the conveying table 10 by simultaneously driving the first conveying mechanism 20 and the second conveying mechanism 40A.

[First conveying mechanism 20: FIGS. 1 and 2]
The first transport mechanism 20 is composed of a rotary body drive mechanism that transports the mold DE while placing the mold DE via its bottom surface SS on a roller, which is an example of a rotary body that rotates on its axis due to a drive source.
As shown in Figures 1 and 2, the first conveying mechanism 20 includes conveying rollers 21 spaced apart from one another in the conveying direction X, and sprockets 23 fixed coaxially to the conveying rollers 21 at one end of each conveying roller 21 in the width direction Y.
Both ends of each of the conveying rollers 21 are rotatably supported by the conveying table 10. The material and dimensions of the conveying rollers 21 are specified so that they can withstand the load of the mold DE placed on them. Some of the conveying rollers 21 can also be replaced with free-rotating rollers.

The first conveying mechanism 20 includes an endless roller drive chain 25 that is stretched around each of the sprockets 23 , and a first drive source 27 that moves the roller drive chain 25 in a circular motion.
The first drive source 27 is composed of, for example, an electric motor (first electric motor) that can rotate forward and backward. FIG. 1 shows an example in which the first drive source 27 rotates forward, as indicated by the arrow. When the first drive source 27 rotates forward, the first transport mechanism 20 can transport the mold DE in a direction X1 toward the mold placement area 117. When the first drive source 27 rotates reversely, the first transport mechanism 20 can transport the mold DE from the mold placement area 117 toward the load/unload position 19 in a direction X2. In either transport mode, the mold DE is placed on transport rollers 21, and the drive force of the transport rollers 21 is applied to its bottom surface SS.

By employing a roller drive mechanism in the first conveying mechanism 20 that is highly rigid and easy to rotate even when a large load is applied to the outer peripheral surface of the conveying roller 21 on which the mold DE is placed, even if the mold DE, which is a heavy object, is placed and supported directly from the direction of gravity, bending deformation that would impede the rotation of the conveying roller 21 does not occur, and the mold DE can be easily moved in the conveying direction.
In this embodiment, the outer circumferential surface of the conveying roller 21 on which the mold DE is placed is flat, but the roller in the present invention is not limited to this. For example, a roller with an uneven outer circumferential surface, like a sprocket that constitutes a chain drive mechanism and has teeth formed on its outer circumferential surface, may be used as the rotating body. If the roller that conveys the mold DE has an uneven outer circumferential surface, the uneven outer circumferential surface can be engaged with intermittent grooves or holes (not shown) provided in the mold DE, preventing the mold DE from slipping on the conveying roller 21 during conveyance.
In addition, although it is assumed here that the mold DE is simply placed on the conveying rollers 21 and not restrained by other mechanical means, "placed" in this invention also includes cases where the mold DE is mechanically restrained. For example, it is a case where the mold DE is loosely restrained in the vertical direction V, such as to prevent the bottom surface SS of the mold DE from floating up.

[Second conveying mechanism 40A: FIGS. 1 and 2]
Next, the second transport mechanism 40A is a chain drive mechanism that transports the mold DE using a snake chain that is moved back and forth by a drive source. The second transport mechanism 40A applies a driving force to the mold DE that is placed on the transport rollers 21 at the center in the width direction Y. In this embodiment, the second transport mechanism 40A is exemplified as a snake chain, but it is not limited to a snake chain and can be any member that can be wound up and transmit thrust in the axial direction.

As shown in Figures 1 and 2, the second transport mechanism 40A comprises a snake chain 41, a second drive source 47 that engages with one end of the snake chain 41 and moves the snake chain 41 back and forth, and a connecting piece 49 that is attached to the other end of the snake chain 41 and can be attached to and detached from the mold DE. The connecting piece 49 is attached to the mold DE by fastening means such as a bolt and nut. The side of the snake chain 41 that engages with the second drive source 47 is referred to as the rear, and the side where the connecting piece 49 is provided is referred to as the front.

The snake chain 41 is movable back and forth along a chain guide (not shown). The front side of the snake chain 41 is hung on a sprocket 46 that is rotatable by a second drive source 47. When the sprocket 46 is rotated forward or backward, the hung snake chain 41 is unwound or wound around the sprocket 46. When the snake chain 41 moves back and forth in response to this unwound or wound, the thrust from the second drive source 47 is transmitted without bending the snake chain 41, and the mold DE, which is a heavy object, can be moved in the direction X1 or the direction X2.
The snake chain 41 is formed by, for example, connecting two types of link elements, outer links 42 and inner links 43, in an alternating combination.

Like the first drive source 27 described above, the second drive source 47 is composed of, for example, an electric motor (second electric motor) capable of forward and reverse rotation. The direction in which the second drive source 47 transports the mold DE through forward and reverse rotation is the same as that of the first drive source 27. In other words, when the second drive source 47 rotates forward, the second transport mechanism 40A can transport the mold DE toward the mold placement area 117, and when the second drive source 47 rotates reverse, the second transport mechanism 40A can transport the mold DE from the mold placement area 117 toward the loading/unloading position 19. In either direction X1 or X2, a driving force is applied to the back surface BS of the mold DE placed on the transport rollers 21, at a position away from the transport rollers 21 in the height direction Z, via a connecting piece 49 detachable from the mold DE. The joining piece 49 has a predetermined area in the width direction Y and height direction Z, and is detachably connected to the mold DE at a position spaced apart in the height direction Z from the bottom surface SS of the mold DE. A wide variety of known attachment and detachment methods are used to attach and detach the joining piece 49 to the mold DE, including fastening means such as bolts and nuts, as well as gripping using claws or compressive force, or adhesion using magnetic force or suction. The snake chain 41 is also connected to the joining piece 49. The snake chain 41 is preferably connected to the joining piece 49 at the center of the area of the joining piece 49.

[Transportation of mold DE: Figures 3 and 4]
3 and 4, the operation of using the mold transport device 1A to transport the mold DE from the carry-in/carry-out position 19 toward the mold placement area 117 of the injection molding machine 100 will be described. Note that the upper diagram of Fig. 3 shows the state in which the mold DE is placed at the carry-in/carry-out position 19 and transport begins, and the lower diagram of Fig. 3 shows the state in which the mold DE is midway through transport to the mold placement area 117.

The transport of the mold DE begins by rotating the first drive source 27 of the first transport mechanism 20 in the forward direction and the second drive source 47 of the second transport mechanism 40A in the forward direction. Two transport mechanisms, the first transport mechanism 20 and the second transport mechanism 40A, are provided, and the transport speed V20 of the mold DE by the first transport mechanism 20 and the transport speed V40 of the mold DE by the second transport mechanism 40A are synchronized. Here, the drive force for transporting the mold DE by the forward rotation of the first drive source 27 is P1 (P11, P12), and the drive force for transporting the mold DE by the forward rotation of the second drive source 47 is P2 (P21, P22). The mold DE continues to be transported toward the mold placement area 117 by drive forces P1 and P2.

When the mold DE has been transported to the target mold placement area 117, the first drive source 27 and the second drive source 47 are stopped. Next, the joining piece 49 of the second transport mechanism 40A is removed from the mold DE, and the second drive source 47 is rotated in the reverse direction until the joining piece 49 moves to the initial loading/unloading position 19. The first drive source 27 and the second drive source 47 are stopped until the next mold DE is transported.

The above explanation has been given of an example of transporting a mold DE consisting of a set of fixed mold DE1 and movable mold DE2, but in this embodiment, the fixed mold DE1 and movable mold DE2 may also be transported separately. For example, if the fixed mold DE1 is transported first, the next mold DE is transported by transporting the movable mold DE2 from the load/unload position 19 toward the mold placement area 117. Also, if the previous molds DE are transported by both the fixed mold DE1 and the movable mold DE2, the next mold DE is transported by transporting the fixed mold DE1 and movable mold DE2 from the mold placement area 117 toward the load/unload position 19 to replace the mold DE that has completed a predetermined number of injection moldings.

[Effects of mold conveying device 1A]
Next, the effects obtained by the mold conveying device 1 will be described.
[Effect on the behavior of the mold DE during transport operation: Figure 5]
5(a) and 5(b), if only the 1-1 driving force P11 or the 1-2 driving force P12 is applied by the first transport mechanism 20 during the transport of the mold DE, the 1-1 driving force P11 or the 1-2 driving force P12 is transmitted to the mold DE via the bottom surface SS of the mold DE that is in contact with the transport roller 21. Here, the 1-1 driving force P11 indicates acceleration, and the 1-2 driving force P12 indicates deceleration.

When the first-1 driving force P11 is applied to the bottom surface SS of the mold DE in the horizontal direction H in this way, during acceleration, the first-1 driving force P11 becomes a load W11 acting on the center of gravity G of the mold DE, generating a clockwise moment M11 in the figure on the mold DE. In particular, when a large first-1 driving force P11 is applied to the bottom surface SS of the mold DE in an attempt to transport the mold DE at high speed, as shown in FIG. 5, the moment M11 acting on a taller mold DE (FIG. 5(b)) is larger than that acting on a shorter mold DE (FIG. 5(a)). In particular, when acceleration occurs immediately after starting to drive the first driving source 27 and applying the first-1 driving force P11, or when the driving force P11 is increased to accelerate while the first driving source 27 is being driven, the front surface FS of the mold DE in the transport direction X may lift off the transport rollers 21.

Conversely, during deceleration, the first-second driving force P12 acts on the center of gravity G of the mold DE as a load W12 in the opposite direction to that during acceleration, generating a counterclockwise moment M12 on the mold DE. In particular, if a large first-second driving force P12 is applied to the bottom surface SS of the mold DE as a braking force to decelerate a mold DE being transported at high speed, the moment M12 acting on a tall mold DE (Figure 5(b)) will be larger than that acting on a short mold DE (Figure 5(a)). In particular, when the first-second driving force P12 is applied as a braking force by deceleration driving of the first driving source 27, the back surface BS side of the mold DE in the transport direction X may lift off the transport rollers 21.

The floating that occurs during acceleration or deceleration will eventually subside, but when the bottom surface SS of the floating mold DE lands on the conveying roller 21, an impact and a collision noise will occur. Furthermore, depending on the degree of impact when the mold DE lands, it may cause the mold DE to shift position or damage the conveying roller 21.

However, the mold conveying device 1A includes a second conveying mechanism 40A in addition to the first conveying mechanism 20. While the second driving source 47 is rotating forward, the joining piece 49 of the second conveying mechanism 40A presses the back surface BS of the mold DE with a second-first driving force P21, as shown in FIG. 5C. The load W21 acting on the center of gravity G due to the second-first driving force P21 pressing the back surface BS is directed in the opposite direction to the load W11 acting on the center of gravity G due to the first-first driving force P11. Therefore, the load W21 generates a counterclockwise moment M21 that cancels out the clockwise moment M11. The second-first driving force P21, which generates the moment M21, is intended to convey the mold DE, just like the first-first driving force P11, which generates the moment M11. Therefore, the second-first driving force P21 has a magnitude sufficient to cancel out the moment M11 and prevent the front surface FS (front end surface) of the mold DE from lifting up.
Figure 5(c) shows an example of acceleration, but when decelerating, a load, driving force, and moment are generated in the opposite direction to those in Figure 5(c), preventing the back surface BS (rear end surface) of the mold DE from lifting up.

5C shows three second-1 driving forces P21, and the second-1 driving force P21 at any position can generate a moment M21. If it only opposes the moment M11, the second-1 driving force P21 farthest from the bottom surface SS of the mold DE can have a small value.
Generally, since the mold DE is a heavy object, even if a moment M11 is generated when a large first-first driving force P11 is applied, which would result in high acceleration for speedup, most of the moment M11 is canceled out by the inertia of the weight of the mold DE. Therefore, the second-first driving force P21, which counteracts the remaining moment M11, does not need to be a large thrust. Furthermore, if the second-first driving force P21 is greater than the first-first driving force P11, the second-first driving force P21 will be the main thrust for transporting the mold DE, resulting in a large reaction force from the mold DE generated on the snake chain 41. In this case, bending at each pin of the steel snake chain 41 may reduce the thrust, so it is preferable that P11 > P21 during acceleration. Assuming P11 > P21, lifting can be prevented within the range of P21 = (0.1 to 0.3) x P11. This relationship between the first-1st driving force P11 and the second-1st driving force P21 also applies to acceleration in the second embodiment.

When decelerating a mold DE moving at high speed, a large braking force is required because the mold DE is a heavy object with large inertia. Furthermore, to decelerate the mold DE, the driving force P2 must be in the opposite direction to the inertial force of the mold DE, i.e., the opposite direction to that during acceleration. In other words, because the snake chain 41 is connected to the mold DE via the connecting piece 49, a tensile force acts on the snake chain 41 due to the inertial force of the mold DE. In this case, the snake chain 41 is stretched, preventing bending at the pins of the steel snake chain 41. Therefore, the second-second driving force P22 may be greater than the first-second driving force P12. Furthermore, because the inertial force is large during sudden deceleration from high speed, when a large driving force P12, which is a braking force, is applied to the deceleration side, a large moment M22 is generated that causes the mold DE to tip in the direction of transport due to the inertial force. To overcome this large moment M22 and prevent the back surface BS of the mold DE from lifting in the transport direction, it is preferable that P12≦P22. This relationship between the first-second driving force P12 and the second-second driving force P22 also applies during deceleration in the second embodiment.

[Effect of increasing the speed of conveying operations]
High efficiency is required for the production of resin products using the injection molding machine 100, and it is also necessary to shorten the time required to transport and replace the mold DE. To meet this demand, the mold DE can be transported at a higher speed, and the mold transport device 1 is suitable for this high-speed transport.
For example, if the molds DE are transported by a single transport mechanism, such as the first transport mechanism 20, then in order to increase the transport speed, the first drive source 27 of the first transport mechanism 20 must be made more powerful, which requires the first drive source 27 to be made larger. This increases the installation space, so a site corresponding to the increased installation space must be secured. Furthermore, increasing the size of the first drive source 27 also increases the size of its components, which means that commercially available components cannot be used and must be ordered individually, resulting in increased costs for the components.

However, the mold conveying device 1B is equipped with two drive sources: a first drive source 27 for the first conveying mechanism 20 and a second drive source 47 for the second conveying mechanism 40A. When conveying the mold DE, the first drive source 27 generates a drive force P1 and the second drive source 47 generates a drive force P2 simultaneously. Even if the first drive source 27 and the second drive source 47 are small and not enlarged, their cooperation allows for high-speed conveying of the mold DE. Moreover, the first drive source 27 and the second drive source 47 can each be small and made using commercially available parts, which reduces material costs and enables the conveying device to be manufactured in a short period of time. At the same time, there is no increase in installation space.

[Effect of improving the transfer accuracy of the mold DE]
The mold conveying device 1A is equipped with two conveying mechanisms, a first conveying mechanism 20 and a second conveying mechanism 40A, and synchronizes the conveying speed V20 of the mold DE by the first conveying mechanism 20 with the conveying speed V40 of the mold DE by the second conveying mechanism 40A as described above. This prevents the mold DE from slipping on the conveying rollers 21 of the first conveying mechanism 20, and the conveying force of the conveying rollers 21 and the conveying force of the snake chain 41 are each used to convey the mold DE without loss. Therefore, the mold conveying device 1A can control the conveying speed and conveying position of the mold DE at high speed and with high precision.

[Effect of transporting the mold DE using a chain drive mechanism]
By using the snake chain 41 for the second transport mechanism 40A, it is possible to reduce the space required for the second transport mechanism 40A. Because the snake chain 41 can be wound up or unwound, the long chain can be rolled up and stored compactly. Furthermore, the same effect can be obtained by replacing the snake chain 41 with a mechanism that can be wound up or unwound and can transmit thrust in the transport direction X.

[Second embodiment: Figs. 6 and 7]
Next, a mold conveying device 1B according to a second embodiment will be described with reference to Fig. 6. The second conveying mechanism 40A of the mold conveying device 1A uses a chain drive mechanism to move the mold DE back and forth, while the second conveying mechanism 40B of the mold conveying device 1B uses a piston-cylinder mechanism driven by fluid pressure to move the mold DE back and forth. The first conveying mechanism 20 of the mold conveying device 1B and the mold conveying device 1A has the same configuration, and therefore the same reference numerals as in the first embodiment are used in Figs. 6 and 7, and a description thereof will be omitted.

As shown in FIG. 6, the second transport mechanism 40B comprises a piston-cylinder mechanism 50 mounted on the transport table 10. The piston-cylinder mechanism 50 comprises a cylinder 51, a piston rod 53 that reciprocates within the cylinder 51, and a piston head 55 connected to the rear end of the piston rod 53 inside the cylinder 51. The piston-cylinder mechanism 50 is a fluid pressure drive source that reciprocates the piston rod 53 and piston head 55 using hydraulic or pneumatic pressure. The piston-cylinder mechanism 50 comprises a connecting piece 57 mounted on the tip of the piston rod 53 outside the cylinder 51. As an example, the connecting piece 57 is attached to the back surface BS of the mold DE when the mold DE is transported. The same means as in the first embodiment can be used to connect the connecting piece 57 to the mold DE.

[Transportation of mold DE: Figure 7]
7, the operation of using the mold transport device 1B to transport the mold DE from the carry-in/carry-out position 19 toward the mold placement area 117 of the injection molding machine 100 will be described. Note that the upper diagram of Fig. 7 shows the state in which the mold DE is placed at the carry-in/carry-out position 19 and transport begins, and the lower diagram of Fig. 7 shows the state in which the mold DE is midway through transport to the mold placement area 117.

Transport of the mold DE begins by rotating the first drive source 27 of the first transport mechanism 20 in the forward direction and advancing the piston rod 53 of the piston-cylinder mechanism 50 of the second transport mechanism 40B.

Once the mold DE has been transported to the desired mold placement area 117, the operation of the first drive source 27 and piston-cylinder mechanism 50 is stopped. Next, the joining piece 57 of the second transport mechanism 40B is removed from the mold DE, and the piston rod 53 of the piston-cylinder mechanism 50 is retracted until the joining piece 57 moves to the original loading/unloading position 19. The first drive source 27 and piston-cylinder mechanism 50 are stopped from driving until the next mold DE is transported.

[Effects of mold conveying device 1B]
The mold conveying device 1B has the same effects as the mold conveying device 1A, except for the effect of conveying the mold DE by a chain drive mechanism, and in addition has the following effects.
By using the piston-cylinder mechanism 50 in the second transport mechanism 40B, the mold transport force acting on the back surface BS of the mold DE can be efficiently applied to the mold DE. The piston-cylinder mechanism 50 has high rigidity in the thrust direction, and can apply hydraulic thrust to the mold DE without losing it by bending in a direction other than the thrust direction (for example, a direction perpendicular to the thrust direction).

In addition to the above, the configurations given in the above embodiments can be selected or changed as appropriate to other configurations without departing from the spirit of the present invention.
For example, in the first and second embodiments, the second transport mechanisms 40A, 40B apply a second-1 driving force P21 that pushes the back surface BS of the mold DE when transporting the mold DE in the direction X1, or apply a second-2 driving force P22 that pulls the back surface BS of the mold DE when slowing down the transport speed of the mold DE in the direction X2, but the present invention is not limited to this. That is, it is also possible to attach a joining piece 49, 57 to the front surface FS of the mold DE when transporting the mold DE in the direction X1 and apply the second-1 driving force P21 that pulls the joining piece 49, 57, or to attach a joining piece 49, 57 to the front surface FS of the mold DE and apply the second-2 driving force P22 that pushes the joining piece 49, 57 when slowing down the transport speed of the mold DE in the direction X2.

Furthermore, the second conveying mechanism is not limited to a chain drive mechanism or a flow vertical pressure drive mechanism, but can also use a mechanism that converts motor rotation into a linear direction, such as a ball screw mechanism or trapezoidal screw mechanism.

DESCRIPTION OF SYMBOLS 1A, 1B Mold conveying device 10 Conveying table 19 Loading/unloading position 20 First conveying mechanism 21 Conveying roller 23 Sprocket 25 Roller drive chain 27 First driving source 40A, 40B Second conveying mechanism 41 Snake chain 42 Outer link 43 Inner link 46 Sprocket 47 Second driving source 49 Joining piece 49, 57 Joining piece 50 Piston-cylinder mechanism 51 Cylinder 53 Piston rod 55 Piston head 100 Injection molding machine 110 Mold clamping device 111 Fixed mold platen 113 Movable mold platen 115 Tie bar 117 Mold placement area 120 Injection device 121 Heating cylinder 123 Injection nozzle DE Mold DE1 Fixed mold DE2 Movable mold FS Front surface BS Back surface SS Bottom surface G Center of gravity M11, M12, M21 Moment P11 1st-1st driving force P12 1st-2nd driving force P21 2nd-1st driving forces W11, W12, W21 Load V Vertical direction H Horizontal direction X Conveying direction Y Width direction Z Height direction

Claims (5)

A mold conveying device that conveys at least one set of molds, which is a combination of a fixed mold and a movable mold, along a conveying direction,
a first conveying mechanism that conveys the mold in the conveying direction while placing the mold via a bottom surface;
a second conveying mechanism that conveys the mold in the conveying direction while applying a second driving force to a position vertically spaced from the bottom surface of the mold,
the second conveying mechanism is a chain drive mechanism or a fluid pressure cylinder drive mechanism,
driving the first transport mechanism and the second transport mechanism simultaneously to transport the mold;
A mold transport device characterized by:
The first transport mechanism
a drive mechanism including a plurality of rotating bodies arranged in the conveying direction and on which the mold is placed,
The mold transport device according to claim 1 .
3. The mold conveying device according to claim 1, wherein a first electric motor serving as a drive source for the first conveying mechanism and a second electric motor serving as a drive source for the second conveying mechanism are electrically or mechanically synchronized.
The second transport mechanism is
conveying the mold while applying a load in a direction opposite to a moment that may occur in the mold when the first conveying mechanism accelerates or decelerates the conveyance;
The mold transport device according to claim 1 or 2.
During the acceleration,
A first-1 driving force P11 of the mold by the first transport mechanism;
A second-1 driving force P21 of the mold by the second transport mechanism,
P11>P21,
During the deceleration,
A first-second driving force P12 of the mold by the first transport mechanism;
A second-second driving force P22 of the mold by the second transport mechanism,
P12≦P22
The mold transport device according to claim 4.