Mold transport device

Abstract

To provide a mold conveyance device that can convey a mold at a high speed even if a small electric motor is used.SOLUTION: A mold conveyance device 1A conveys at least one set of molds DE that is obtained by combining a fixed mold DE1 and a movable mold DE2 along a conveyance direction. The mold conveyance device 1A comprises: a first conveyance section 20A that conveys the mold DE in the conveyance direction X while placing the mold DE; and a second conveyance section 40A that conveys the mold DE by moving the first conveyance section 20A in the conveyance direction X.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a device for replacing a mold used, for example, in an injection molding machine.

Background Art

[0002] An injection molding machine includes a set of molds for molding a molten resin material into a predetermined shape. One of the set of molds is attached to a fixed platen whose position is fixed in the injection molding machine and is referred to as a fixed mold, and the other of the set of molds is attached to a movable platen that moves forward and backward with respect to the fixed platen and is referred to as a movable mold. In an injection molding machine, a fixed mold and a movable mold corresponding to the molded product to be produced are used. Therefore, it is necessary to replace the fixed mold and the movable mold according to the molded product.

[0003] For the conventional mold replacement method of manually transporting a mold placed on a rotating roller, Patent Document 1 proposes providing, in addition to a plurality of sprockets rotationally driven by rotational driving means, a rack member provided near the lower end of the mold and driven by the sprockets. When the rotational driving means of the mold transfer device of Cited Document 1 is operated, the rotation of the sprockets transports the mold placed on the sprockets, and the operation of the rack member integrally transports the rack member and the mold. According to Patent Document 1, since the mold is moved by the rotational driving means, the mold moving speed can be increased, the stop position accuracy of the mold can be increased, and the time required for mold replacement can be shortened.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Molds are heavy objects, and transporting them by rollers, including the sprocket, requires significant driving force. Therefore, when driving the rollers with an electric motor, a high-torque electric motor is necessary. This requires a large, high-capacity, specialized motor, which increases space and cost. As a countermeasure, when using a small or medium-sized motor, a reduction gear can be interposed between the electric motor and the roller. However, while a reduction gear can add high torque to the roller, it reduces the roller's rotation speed. Naturally, a lower roller rotation speed reduces the mold transport speed. In this case, the setup time for mold changes increases, reducing productivity.

[0006] Therefore, the present invention aims to provide a mold transport device that can transport molds at high speed even when using a small electric motor. [Means for solving the problem]

[0007] The mold transport device of the present invention transports at least one set of molds, which consist of a fixed mold and a movable mold, along the transport direction. The mold transport device of the present invention comprises a first transport unit that transports the molds in the transport direction while the molds are placed on it, and a second transport unit that transports the molds by moving the first transport unit in the transport direction.

[0008] The first conveying unit in the present invention preferably includes a rolling roller consisting of a rotating roller or a free-rotating roller on which a mold is placed. When the rolling roller is a rotating roller, the first conveying unit includes a drive mechanism for rotating the rotating roller. When the rolling roller is a free-rotating roller, it includes a drive mechanism for pushing the mold placed on the free-rotating roller in the conveying direction.

[0009] The drive mechanism of the second transport unit in the present invention preferably consists of a chain drive mechanism, a fluid pressure cylinder mechanism, and a rotary-to-linear motion conversion mechanism.

[0010] In the mold transfer device of the present invention, when the transfer speed of the mold by the first transfer unit is V20 and the transfer speed of the mold by the second transfer unit is V40, it is preferable to transfer the mold with V20 < V40.

[0011] In the mold transfer device of the present invention, from the start to the end of the mold transfer, the transfer of the mold by the first transfer unit and the transfer of the mold by the second transfer unit are performed in parallel, or the transfer of the mold by the first transfer unit and the transfer of the mold by the second transfer unit are selectively performed. When transferring the mold by one or both of the first transfer unit and the second transfer unit to the mold placement area between the fixed mold plate and the movable mold plate, it is preferable that the mold undergoes deceleration and acceleration.

[0012] In the mold transfer device of the present invention, it is preferable that the mold transferred between the fixed mold plate to which the fixed mold is attached and the movable mold plate to which the movable mold is attached is provided with a braking unit that loads a braking force in the direction opposite to the transfer direction.

[0013] The braking unit in the present invention loads a braking force between the fixed mold plate and the movable mold plate so that the moving speed of the mold decreases.

[0014] The braking unit in the present invention preferably controls the moving speed of the mold to accelerate for a predetermined time and then decelerate again to stop just before the mold reaches the end of the first transfer unit or the mold placement area between the fixed mold plate and the movable mold plate.

Advantages of the Invention

[0015] According to the mold transfer device of the present invention, the first transfer unit is mounted on the second transfer unit. The mold transferred to the mold transfer device is transferred at a speed (V20 + V40) obtained by adding the transfer speed V40 of the second transfer unit to the transfer speed V20 of the first transfer unit.

Brief Description of the Drawings

[0016] [Figure 1] It is a side view showing a mold transfer device according to the first embodiment. [Figure 2] It is a plan view showing a mold transfer device according to the first embodiment. [Figure 3] It is a side view showing a process of transferring a mold by the mold transfer device according to the first embodiment. [Figure 4] It is a plan view showing a process of transferring a mold by the mold transfer device according to the first embodiment. [Figure 5] It is a graph showing a transfer pattern by the mold transfer device according to the first embodiment. [Figure 6] It is a graph showing a transfer pattern when transferring from the first transfer unit to the support roller by the mold transfer device according to the first embodiment. [Figure 7] It is a side view showing a first modification example of the mold transfer device according to the first embodiment. [Figure 8] It is a side view showing a second modification example of the mold transfer device according to the first embodiment. [Figure 9] It is a side view showing a third modification example of the mold transfer device according to the first embodiment. [Figure 10] It is a side view showing a fourth modification example of the mold transfer device according to the first embodiment. [Figure 11] It is a side view showing a mold transfer device according to the second embodiment. [Figure 12] It is a side view showing a modification example of the mold transfer device according to the second embodiment. [Figure 13] It is a side view showing a modification example of the mold transfer device according to the second embodiment.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, two embodiments, namely, a preferred first embodiment and a second embodiment of the present invention will be described with reference to the accompanying drawings. The first embodiment provides two transport means, a first transport unit and a second transport unit, for transporting molds, enabling high-speed transport of molds even with a small electric motor. The second embodiment proposes a braking device that operates between a fixed platen and a movable platen and applies a braking force to the mold in the opposite direction to the transport direction. This braking device is applied to the first embodiment, but can also be applied to mold transport devices with other configurations. The first and second embodiments will be described below in that order.

[0018] [First Embodiment: Figures 1, 2, 3, 4, 5] A mold transfer device 1A according to the first embodiment will be described with reference to Figures 1 to 5. The mold transport device 1A transports a mold DE, which has been brought in from the storage area to the mold loading / unloading position 19, toward the mold placement area 117. Once transported to the mold placement area 117, the mold DE is attached to the fixed mold plate 111 and the movable mold plate 113 and awaits injection molding. When unloading the mold DE from the mold placement area 117, the transport is carried out in the reverse order of the loading procedure described above. A mold DE consists of a set of fixed mold DE1 and movable mold DE2. When there is no need to distinguish between fixed mold DE1 and movable mold DE2, they are collectively referred to as mold DE.

[0019] The basic functions of the mold transport device 1A are as described above. The mold transport device 1A includes a first transport section 20A that directly carries and transports the mold DE, and a second transport section 40A that carries the first transport section 20A and moves the first transport section 20A in the transport direction. Below, an overview of the injection molding machine 100 will be described, followed by a detailed description of the mold transport device 1A.

[0020] [Injection molding machine 100] The main components of the injection molding machine 100 to which the mold transfer device 1A is applied will be described. The injection molding machine 100 is equipped with a mold clamping device 110 and an injection device 120. The mold clamping device 110 comprises a fixed mold plate 111 to which a fixed mold DE1 is attached, and a movable mold plate 113 to which a movable mold DE2 is attached. A cavity corresponding to the molded product is formed between the fixed mold DE1 attached to the fixed mold plate 111 and the movable mold DE2 attached to the movable mold plate 113, and a molded product is obtained by injecting molten resin from the injection device 120 into this cavity. In order to apply a clamping force between the fixed mold DE1 and the movable mold DE2 during injection molding, the mold clamping device 110 is equipped with a plurality of tie bars 115 that penetrate the fixed mold plate 111 and the movable mold plate 113, and a drive source such as a hydraulic cylinder (not shown). Between the fixed mold plate 111 and the movable mold plate 113, a mold arrangement area 117 is formed where the fixed mold DE1 and the movable mold DE2 are arranged and fixed. In this embodiment, the mold DE is exemplified as a set of mold DE consisting of a fixed mold DE1 and a movable mold DE2. However, in order to perform molding using multiple cavities or multiple molds, such as in so-called family mold molding, mold DE consisting of multiple sets of fixed mold DE1 and movable mold DE2 may be attached to the fixed mold platen 111 and the movable mold platen 113.

[0021] The injection molding device 120 includes a heating cylinder 121 for heating and melting solid resin material, and an injection nozzle 123 for discharging the molten resin material obtained from the heating cylinder 121 towards the cavity between the fixed mold DE1 and the movable mold DE2. Inside the heating cylinder 121 is a screw (not shown) for kneading and melting the supplied resin material. A heater is also provided around the heating cylinder 121 for heating the resin material supplied inside. By heating the resin material with the heater and rotating the screw, the solid resin material is melted inside the heating cylinder 121 for use in injection molding. The mold transfer device 1A is not limited to injection molding machines 100, but can also be applied to casting equipment such as die casting machines and extrusion presses where the replacement of heavy molds is required.

[0022] [Overall configuration of mold transfer device 1A: Figures 1 and 2] As shown in Figures 1 and 2, the mold transport device 1A includes a fixed table 10 on which a mold DE is transported from the loading / unloading position 19 of the fixed table 10 toward the mold placement area 117 of the injection molding machine 100, or from the mold placement area 117 toward the loading / unloading position 19. The mold transport device 1A also includes a first transport section 20A on the fixed table 10 that loads the mold DE onto its bottom surface and transports it by applying a driving force in the transport direction X. Furthermore, the mold transport device 1A includes a second transport section 40A that transports the first transport section 20A on which the mold DE is loaded toward the transport direction X. The second transport section 40A transports the first transport section 20A with the first transport section 20A loaded on it. In the mold transport device 1A, the transport direction X, width direction Y, and height direction Z are defined as shown in Figures 1 and 2. In this embodiment, "direction" is a general term that includes two orientations. For example, the transport direction X includes the orientation from the loading / unloading position 19 to the mold placement area 117 (X1) and the orientation from the mold placement area 117 to the loading / unloading position 19 (X2).

[0023] [Fixed table 10: Figures 1 and 2] The fixed table 10 is fixed in position and mounts elements of the mold transport device 1A, including the first transport section 20A and the second transport section 40A. The mold transport device 1A transports the mold DE on the fixed table 10 in cooperation with the first transport section 20A and the second transport section 40A, which are driven simultaneously.

[0024] [First transport section 20A: Figures 1 and 2] The first transport unit 20A consists of a rotary body drive mechanism that transports the mold DE by placing it on a roller, which is an example of a rotating body that rotates on its own axis due to a drive source, via its bottom surface. As shown in Figures 1 and 2, the first conveying unit 20A comprises conveying rollers 21 arranged at intervals in the conveying direction X, and a sprocket 23 fixed coaxially with the conveying roller 21 to one end of each conveying roller 21 in the width direction Y. Each conveying roller 21 is rotatably supported at both ends by the moving table 41 of the second conveying unit 40A. 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 rotating conveying rollers 21 can be replaced with free-rotating rollers. Both rotating rollers and free-rotating rollers are considered rolling rollers.

[0025] The first transport unit 20A includes an endless roller drive chain 25 stretched across each sprocket 23, and a first drive source 26 that causes the roller drive chain 25 to rotate. The first drive source 26 is composed of, for example, an electric motor capable of forward and reverse rotation of its rotating shaft 27. Figure 1 shows an example in which the first drive source 26, indicated by the arrow, is rotated forward (counterclockwise in the figure). When the first drive source 26 rotates forward, the first transport unit 20A can transport the mold DE toward the mold placement area 117 in direction X1. When the first drive source 26 reverses direction, the first transport unit 20A can transport the mold DE toward the loading / unloading position 19 from the mold placement area 117 in direction X2. In either transport operation, the mold DE is placed on the transport rollers 21, and the driving force from the transport rollers 21 is applied to its bottom surface.

[0026] By employing a roller drive mechanism in the first transport section 20A that is highly rigid and easily rotated even when a large load is applied to the outer surface of the transport roller 21 on which the mold DE is placed, even when the heavy mold DE is placed directly on it from the direction of gravity, bending deformation that would hinder the rotation of the transport roller 21 does not occur, and the mold DE can be easily moved in the transport direction. In this embodiment, the conveying roller 21 has a flat outer surface on which the mold DE is placed, but the roller in this invention is not limited to this. For example, a roller with irregularities on its outer surface, such as a sprocket with teeth formed on its outer surface, may be used as a rotating body. In this case, it is preferable that the mold DE is provided with intermittent grooves or holes and irregularities on its outer surface. If the roller that conveys the mold DE has irregularities on its outer surface, the intermittent grooves or holes (not shown) provided on the mold DE and the irregularities on its outer surface will engage, preventing the mold DE from slipping on the conveying roller 21 during conveyance. Furthermore, while this invention assumes that the mold DE is not simply placed on the transport roller 21 and not restrained by other mechanical means, the term "placed" in this invention includes cases where the mold DE is mechanically restrained.

[0027] [Second transport section 40A: Figures 1 and 2] Next, the second transport unit 40A moves the first transport unit 20A forward and backward in the transport direction X(X1,X2). This forward and backward movement is performed with the first transport unit 20A resting on the second transport unit 40A. In other words, the first transport unit 20A directly transports the mold DE, while the second transport unit 40A indirectly transports the mold DE by moving the first transport unit 20A.

[0028] As shown in Figures 1 and 2, the second transport unit 40A includes a movable table 41 that can move on the fixed table 10 in the transport direction X, a snake chain 43 that transmits driving force to the movable table 41, and a second drive source 45 that provides driving force to the snake chain 43.

[0029] The mobile table 41 is equipped with the transport rollers 21, sprockets 23, roller drive chain 25, and first drive source 26, which are elements that make up the first transport unit 20A. The mobile table 41 is made up of a flat metal member that extends in the transport direction X and the width direction Y. The mobile table 41 is guided by a linear guide 42 that restricts movement in directions other than the transport direction X, and transports the mold DE via the first transport unit 20A. The linear guide 42 comprises a guide plate 42A provided on the fixed table 10 and guide tips 42B fixed to both sides of the movable table 41 in the width direction Y. Multiple guide tips 42B are slidably sandwiched between the guide plate 42A on both sides in the width direction Y. In other words, the movable table 41 is slidably mounted on the fixed table 10 via the linear guide 42.

[0030] One end of the snake chain 43 is connected to the rear end of the movable table 41. The snake chain 43 is movable forward and backward along a chain guide (not shown). The other end of the snake chain 43 is stretched over a sprocket 46 which is rotationally driven by a second drive source 45. When the sprocket 46 rotates forward or backward, the snake chain 43 stretched over it is unwound from or wound onto the sprocket 46. As the snake chain 43 moves forward or backward in response to this unwinding or winding, thrust from the second drive source 45 is transmitted, allowing the movable table 41 of the second transport unit 40A, the first transport unit 20A placed on the movable table 41, and the heavy mold DE placed on the first transport unit 20A to move in direction X1 or direction X2.

[0031] The second drive source 45, like the first drive source 26 described above, is composed of, for example, an electric motor capable of forward and reverse rotation. The direction in which the second drive source 45 transports the mold DE due to forward and reverse rotation is the same as that of the first drive source 26. In other words, when the second drive source 45 rotates forward, the second transport unit 40A can transport the mold DE towards the mold placement area 117 via the first transport unit 20A, and when the second drive source 45 rotates in reverse, the second transport unit 40A can transport the mold DE from the mold placement area 117 towards the loading / unloading position 19 via the first transport unit 20A. During this transport, since the first transport unit 20A is driven, the transport speed V40 of the second transport unit 40A is added to the transport speed V20 of the first transport unit 20A for the mold DE.

[0032] [Transport operation of mold DE: Figures 3 and 4] Next, referring to Figures 3 and 4, the operation of transporting the mold DE from the loading / unloading position 19 to the mold placement area 117 of the injection molding machine 100 using the mold transport device 1A will be explained. In Figures 3 and 4, the upper diagram shows the state at which transport of the mold DE, which is placed at the loading / unloading position 19, begins, and the lower diagram shows the state in which the mold DE is being transported to the mold placement area 117.

[0033] The transport of the mold DE is started by rotating the first drive source 26 of the first transport unit 20A in the forward direction and rotating the second drive source 45 of the second transport unit 40A in the forward direction. The system is equipped with two transport means, the first transport unit 20A and the second transport unit 40A, and the transport of the mold DE by the first transport unit 20A and the transport of the mold DE by the second transport unit 40A can be performed synchronously or independently of each other.

[0034] When the mold DE is transported to the mold placement area 117, the first drive source 26 and the second drive source 45 stop driving. Then, after attaching the mold DE to the fixed mold platen 111 and the movable mold platen 113, the second drive source 45 is reversed to return the movable table 41 to its initial position at the start of transport.

[0035] In the above description of the transport operation, an example of transporting a mold DE consisting of a set of fixed mold DE1 and movable mold DE2 was described. However, in this embodiment, the fixed mold DE1 and movable mold DE2 may be transported individually. For example, the fixed mold DE1 can be transported first, followed by the movable mold DE2. If the fixed mold DE1 and movable mold DE2 (mold DE) have been transported first, the next transport of mold DE is the transport of the fixed mold DE1 and movable mold DE2 (mold DE) from the mold placement area 117 toward the loading / unloading position 19 for the purpose of replacing mold DE that has completed a predetermined number of injection moldings. In this case, the transport speeds V20 and V40 can be kept constant, i.e., constant-speed transport can be performed, or one or both of the transport speeds V20 and V40 can be varied in steps or continuously, i.e., variable-speed transport can be performed.

[0036] Furthermore, the above description of the transport operation assumed a pattern in which the transport (operation) by the first transport unit 20A and the transport (operation) by the second transport unit 40A are performed from the start to the end of the transport. However, the present invention can transport the mold DE in various patterns. These transport patterns will be explained with reference to Figure 5. The transport patterns described here are pattern A, in which the first transport unit 20A and the second transport unit 40A are operated simultaneously; pattern B, in which the first transport unit 20A and the second transport unit 40A are operated alternately; and pattern C, which is a combination of pattern A and pattern B.

[0037] [Pattern A: Upper part of Figure 5] In Pattern A, transport by both the first transport unit 20A (V20) and the second transport unit 40A (V40) is carried out continuously from the transport start position S (loading / unloading position 19) to the transport end position E (mold placement area 117). Because Pattern A operates both the first transport unit 20A and the second transport unit 40A throughout the process, the mold DE can be transported faster than in Patterns B and C. Pattern A shown in Figure 5 illustrates an example where the transport speed V40 provided by the second transport unit 40A is faster than the transport speed V20 provided by the first transport unit 20A. However, the opposite is also true; the transport speed V20 may be faster than the transport speed V40. Furthermore, in Pattern A shown in Figure 5, the transport speeds V20 and V40 are constant, i.e., constant-speed transport is performed, except immediately after the transport start position S and immediately before the transport end position E. However, it is also possible to vary one or both of the transport speeds V20 and V40, i.e., variable-speed transport is performed.

[0038] As shown in Pattern A in Figure 5, when the transport speed V40 is faster than the transport speed V20, the following effects occur. Since the second transport unit 40A does not directly transport the mold DE, the transport accuracy of the mold DE may be lower than that of the first transport unit 20A. Therefore, the second drive source 45 of the second transport unit 40A can be a high-capacity electric motor that generates high power but has low drive accuracy, while the first drive source 26 of the first transport unit 20A can be a small to medium-capacity electric motor that is easy to control in terms of drive accuracy. With this combination of electric motors, in addition to reducing the reduction ratio with the high-capacity electric motor in the second drive source 45 to enable high-speed movement, the reduction ratio with the small to medium-capacity electric motor in the first drive source 26 can be increased to reduce the movement speed and improve the positional accuracy of the mold.

[0039] [Pattern B: Middle section of Figure 5] In Pattern B, transport by either the first transport unit 20A (V20) or the second transport unit 40A (V40) precedes the transport, and then switches to the other transport unit midway through. This transport can be called sequential transport by the first transport unit 20A and the second transport unit 40A. Pattern B is applied when there is sufficient setup time, for example, time for changing mold DE, and it is not necessary to increase the transport speed of mold DE.

[0040] Figure 5 specifically shows that the second transport unit 40A performs the transport first, and once the second transport unit 40A has finished transporting, the transport switches to the first transport unit 20A. In the example shown in Figure 5, in the latter half of the transport as it approaches the transport end position E, the deceleration and stopping of the transport of the mold DE can be controlled solely by controlling the first transport unit 20A, making operation control easy. This also applies to pattern C, which will be explained next.

[0041] Pattern B, shown in Figure 5, is as described above. However, in the present invention, transport by the first transport unit 20A is performed first, and once the transport by the first transport unit 20A is completed, the transport can be switched to the second transport unit 40A. Furthermore, in Pattern B shown in Figure 5, the transport speeds V20 and V40 are constant, i.e., constant-speed transport is performed, but it is also possible to vary one or both of the transport speeds V20 and V40 in steps or continuously, i.e., variable-speed transport is performed. These points also apply to Pattern C, which will be described next.

[0042] [Pattern C: Lower section of Figure 5] In pattern C, transport is initially carried out by either the first transport unit 20A (V20) or the second transport unit 40A (V40), and then switched to transport by the other unit midway through. During the period before the switch to transport by the other unit, there is a time when transport is carried out by both the first transport unit 20A and the second transport unit 40A. This pattern C can be described as a transport system that combines patterns A and B.

[0043] [Transfer operation from the first transport unit 20A to the support roller 119: Figure 6] The mold DE, which is transported to the end of the first transport section 20A and close to the injection molding machine 100, is transferred to the support rollers 119 inside the injection molding machine 100. When transporting the mold DE, it is preferable to reduce the transport speed of the mold DE near the end of the first transport section 20A. The reason is as follows. Precisely aligning the height of the first conveying unit 20A with the height of the support roller 119 to create a flush surface may require skilled technique. If the heights of the first conveying unit 20A and the support roller 119 differ, creating a step, moving the mold DE from the first conveying unit 20A to the support roller 119 at high speed may cause an impact at the boundary between the first conveying unit 20A and the support roller 119. An example of speed control for the mold DE to suppress this impact will be explained with reference to Figure 6. This example of speed control is Pattern 1, Pattern 2, Pattern 3, and Pattern 4. Patterns 1 to 4 assume that the operation of the second conveying unit 40A is stopped, as shown in Patterns B and C in Figure 5, and that the mold DE is conveyed only by the first conveying unit 20A. Furthermore, this speed control can be performed in the braking unit (130A to 130D) described in the second embodiment, or in a control unit independent of the braking unit (130A to 130D).

[0044] [Pattern 1] Pattern 1 demonstrates the most basic speed control. In Pattern 1, the transport speed of the mold DE is reduced (D11) near the end of the first transport section 20A. The mold DE is reduced in speed but retains its speed as it is transferred to the support roller 119 of the injection molding machine 100. After being transferred to the support roller 119, the mold DE is transported by the support roller 119 while being reduced in speed, and then comes to a stop (D12).

[0045] [Pattern 2] Pattern 2 reduces the transport speed of the mold DE near the end (D21), and temporarily stops the transport of the mold DE at the boundary between the first transport section 20A and the support roller 119 (speed = 0). This also prevents or suppresses the occurrence of impact in that region. After that, the mold DE comes to a stop after accelerating (A21), moving at a constant speed (C21), and decelerating (D22).

[0046] [Pattern 3] Pattern 3 replaces the single-stage deceleration (D11) in Pattern 1 with a two-stage deceleration (D31, D32). In other words, Pattern 3 relatively increases the degree of the preceding deceleration (D31) and relatively decreases the degree of the subsequent deceleration (D32). This shortens the time required for deceleration (D31, D32) while preventing or suppressing the occurrence of impact in that region. After that, the mold DE stops after deceleration (D33).

[0047] [Pattern 4] Pattern 4 accelerates (A41) a portion of the monotonous deceleration (D11) performed by Pattern 1. In other words, Pattern 4 accelerates (A41) following the preceding deceleration (D41). This allows the mold DE, which tilted forward due to inertia during deceleration (D41), to be straightened by the instantaneous acceleration (A41). The time for accelerating (A41) the transport speed is preferably around 0.05 to 0.5 seconds. If it is shorter than 0.05 seconds, the acceleration will end before the mold DE's tilt is straightened, and if it is longer than 0.5 seconds, although the tilt of the mold DE will be straightened, the acceleration may cause insufficient re-deceleration of the mold DE, potentially resulting in an unstable stopping position. After acceleration (A41), the mold DE decelerates (D42) and then stops.

[0048] Furthermore, the deceleration and acceleration elements in Patterns 1 to 4 can be combined. For example, by incorporating acceleration (A41) during the deceleration and stopping (D21) in Pattern 2, a speed control pattern of deceleration, acceleration, deceleration, and stopping can be created. In addition, deceleration mitigation or acceleration can be performed just before the transport speed reaches zero, i.e., just before the mold DE stops. This stopping occurs at the points indicated as deceleration D12, deceleration D22, deceleration D33, and deceleration D42 in Figure 6.

[0049] Furthermore, while patterns 1 to 4 show examples where the mold DE is transported by the first transport unit 20A alone to the vicinity of the injection molding machine 100, i.e., to the transport end position E, in the case where the mold DE is transported by both the first transport unit 20A and the second transport unit 40A to the transport end position E, as in pattern A of Figure 5, the transport speed of the mold DE is controlled by the sum of both units (V20 + V40). Also, in the aforementioned patterns B or C, the transport by the first transport unit 20A is performed first, and once the transport by the first transport unit 20A is completed, the transport is switched to the second transport unit 40A thereafter. In this pattern where the mold is transported by the second transport unit 40A alone to the transport end position E, the transport speed of the second transport unit 40A is controlled. In other words, the control of deceleration, acceleration, and stopping in patterns 1 to 4 is performed by either the first transport unit 20A alone, the second transport unit 40A alone, or the sum of the first transport unit 20A and the second transport unit 40A.

[0050] [Effects of mold transfer device 1A] Next, we will explain the effects obtained by the mold transfer device 1A. [Increasing the speed of mold transport] The mold transport device 1A has a structure in which the first transport unit 20A is mounted on the second transport unit 40A. The mold DE transported by the mold transport device 1A is transported toward the ground at a transport speed (V20 + V40) which is the sum of the transport speed V20 by the first transport unit 20A and the transport speed V40 by the second transport unit 40A. If small electric motors are used for the first drive source 26 and the second drive source 45, and a reduction gear is interposed to obtain the driving force to transport the mold DE, the transport speeds V20 and V40 will each become slower. However, with the mold transport device 1A where the transport speeds V20 and V40 are added together, the mold DE can be transported at high speed. This makes it easy to increase the transport speed of the mold DE.

[0051] According to the mold transfer device 1A, high-speed transfer of mold DE can be achieved with a small electric motor as the drive source, so commercially available components can be used as the drive source, which reduces component costs and enables the manufacture of the transfer device in a short period of time.

[0052] Furthermore, in the mold transport device 1A, the mold DE is moved and transported by the first transport section 20A and the second transport section 40A. Since the transport speeds of the first transport section 20A and the second transport section 40A can be controlled independently of each other, the transport speed can be easily controlled and there is a degree of flexibility.

[0053] [Effects on increasing the speed of transport operations] In order to achieve high efficiency in the production of resin products using the injection molding machine 100, it is necessary to shorten the time required for transporting and changing molds DE. This can be achieved by increasing the transport speed of molds DE, and the mold transport device 1A is suitable for this high-speed transport. For example, if the mold DE is transported using only a single transport means, the first transport unit 20A, then to increase the transport speed, the first drive source 26 of the first transport unit 20A needs to be made more powerful. To achieve this, the first drive source 26 needs to be made larger so that it can achieve high driving force and high-speed drive even without using a speed reducer, or even with a speed reducer with a small reduction ratio. This increase in size increases the installation space, so a site commensurate with the increased installation space must be secured. Furthermore, increasing the size of the first drive source 26 leads to the increase in the size of its components, and since large components cannot be commercially available, they must be custom-ordered, leading to increased costs for the components.

[0054] However, the mold transport device 1A is equipped with two drive sources: a first drive source 26 for the first transport section 20A and a second drive source 45 for the second transport section 40A. When transporting the mold DE, the drive force P1 of the first drive source 26 and the drive force P2 of the second drive source 45 are generated simultaneously. Even if the first drive source 26 and the second drive source 45 are small and not large in size, their cooperation can accommodate high-speed transport of the mold DE. Moreover, since the first drive source 26 and the second drive source 45 can each be small and made from commercially available components, it is possible to manufacture the transport device in a short period of time while keeping component costs down. At the same time, it does not lead to an increase in installation space.

[0055] [Effects on improving the transport accuracy of mold DEs] The mold transport device 1A is equipped with two transport means, a first transport unit 20A and a second transport unit 40A, and controls the transport speed V20 of the mold DE by the first transport unit 20A and the transport speed V40 of the mold DE by the second transport unit 40A synchronously or independently as described above. By doing so, the degree of freedom in controlling the transport speed of the mold DE, such as acceleration, deceleration, and speed changes, can be improved. Therefore, with the mold transport device 1A, the transport speed and transport position of the mold DE can be controlled at high speed and with high precision.

[0056] [Effects of transporting mold DE using a chain drive mechanism] By using a snake chain 43 in the second conveying section 40A, the space required for the second conveying section 40A can be reduced. Since the snake chain 43 can be wound up or unwound, the long chain can be rolled up and stored compactly. The same effect can also be obtained by using a mechanism that can be wound up or unwound and transmits thrust in the conveying direction X instead of the snake chain 43.

[0057] [Modified version of the first embodiment: Figures 7, 8, 9, 10] Next, four modified examples of the first embodiment will be described with reference to Figures 7 to 10. Each of these modified examples includes second transport sections 40B, 40C, 40D, and 40E in addition to the first transport sections 20A and 20B. The second transport sections 40B to 40D differ from the second transport section 40A in their specific driving means, and the first transport section 20B differs from the first transport section 20A.

[0058] [First modified example: Figure 7] As shown in Figure 7, the mold transport device 1B according to the first modified example moves the mold DE forward and backward using a second transport section 40B with a fluid pressure cylinder mechanism. The first transport section 20A has the same configuration as the mold transport device 1B and the mold transport device 1A, and the same reference numerals as in the first embodiment are used in Figure 6, so its explanation is omitted. The same applies to the second to fourth modified examples.

[0059] The second transport section 40B consists of a fluid pressure cylinder mechanism 50 provided on the fixed table 10, as shown in Figure 7. The fluid pressure cylinder mechanism 50 comprises a cylinder 51, a piston rod 53 that reciprocates inside the cylinder 51, and a piston head 55 connected to the rear end of the piston rod 53 inside the cylinder 51. The fluid pressure cylinder mechanism 50 is a fluid pressure drive source in which the piston rod 53 and piston head 55 reciprocate by hydraulic or pneumatic pressure. The tip of the piston rod 53 is connected to the fixed table 10 outside the cylinder 51 of the fluid pressure cylinder mechanism 50.

[0060] The operation of transporting the mold DE from the loading / unloading position 19 to the mold placement area 117 of the injection molding machine 100 by the mold transport device 1B is as follows. The upper part of Figure 7 shows the state in which the mold DE is placed at the loading / unloading position 19 and transport has started, and the lower part of Figure 7 shows the state in which the mold DE is being transported to the mold placement area 117.

[0061] The transport of the mold DE is initiated by either rotating the first drive source 26 of the first transport unit 20A in the forward direction, or by advancing the piston rod 53 of the fluid pressure cylinder mechanism 50 of the second transport unit 40B. When mold DE is transported to mold placement area 117, the operation of the first drive source 26 and the fluid pressure cylinder mechanism 50 is stopped. Then, after attaching mold DE to the fixed mold platen 111 and the movable mold platen 113, the piston rod 53 of the fluid pressure cylinder mechanism 50 is retracted to its initial position at the start of transport. The first drive source 26 and the fluid pressure cylinder mechanism 50 are stopped until the transport of the next mold DE.

[0062] [Effects of mold transfer device 1B] The mold transport device 1B provides the same effects as the mold transport device 1A, except for the effect of transporting the mold DE by a chain drive mechanism, and also provides the following effects. By using a fluid pressure cylinder mechanism 50 in the second transport section 40B, the transport force can be efficiently applied to the first transport section 20A. Since the thrust direction of the fluid pressure cylinder mechanism 50 is the axial force of the piston, it has high rigidity and does not lose hydraulic thrust by bending in directions other than the thrust direction (for example, perpendicular to the thrust direction), and can be applied to the mold DE.

[0063] [Second modified example: Figure 8] As shown in Figure 8, the mold transport device 1C according to the second modified example uses a ball screw mechanism to move the mold DE forward and backward.

[0064] As shown in Figure 8, the second transport section 40C consists of a ball screw mechanism 60 provided on the fixed table 10. The ball screw mechanism 60 comprises a ball screw 61 and an electric motor 65 that provides rotational driving force to the ball screw 61. The ball screw 61 comprises a ball screw shaft 62 and a ball screw nut 63 that is rotatably fitted onto the ball screw shaft 62. The ball screw shaft 62 is rotatably supported on a support base 64 by bearings (not shown). The rotational driving force of the electric motor 65 supported on the support base 64 is transmitted to the ball screw nut 63 by a transmission belt 67. In addition to the transmission belt 67, known transmission means such as parallel gears, helical gears, or bevel gears may be used, or the electric motor 65 may be directly connected to the ball screw nut 63 for driving. When the ball screw nut 63 is rotated by the rotational driving force from the electric motor 65, the ball screw shaft 62 rotates and moves forward and backward according to the direction of rotation.

[0065] The operation of transporting the mold DE from the loading / unloading position 19 by the mold transport device 1C towards the mold placement area 117 of the injection molding machine 100 is as follows.

[0066] The transport of the mold DE is started by rotating the first drive source 26 of the first transport unit 20A in the forward direction, or by rotating the electric motor 65 of the second transport unit 40C in the forward direction. When the mold DE is transported to the mold placement area 117, the operation of the first drive source 26 and the electric motor 65 of the ball screw mechanism 60 is stopped. Then, after the mold DE is attached to the fixed mold platen 111 and the movable mold platen 113, the electric motor 65 of the second transport unit 40C is reversed to retract the ball screw shaft 62 until the movable table 41 moves to the initial unloading start position. The first drive source 26 and the fluid pressure cylinder mechanism 50 are stopped from driving until the next mold DE is transported.

[0067] [Effects of mold transfer device 1C] The mold transport device 1C provides the same effects as the mold transport device 1A, except for the effect of transporting the mold DE by a chain drive mechanism, and also provides the following effects. By using a ball screw mechanism 60 in the second transport section 40C, the bearing effect of the ball screw mechanism 60 reduces the sliding resistance during operation of the second transport section 40C, thereby reducing the loss of driving force. Furthermore, the operation of the second transport section 40C can be made more responsive to the operation of the electric motor 65. In addition, the noise generated during operation of the second transport section 40C is reduced. In this example, a ball screw was used as the rotation-to-linear motion conversion drive mechanism that converts the rotational driving force from the electric motor 65 into linear motion. However, other rotation-to-linear motion conversion drive mechanisms, such as a rack and pinion drive mechanism, can also be used.

[0068] [Third modified example: Figure 9] As shown in Figure 9, the mold transport device 1D according to the third modified example uses a conveyor mechanism to move the first transport unit 20A forward and backward. As shown in Figure 9, the second conveying unit 40D consists of a conveyor mechanism 70 provided on the fixed table 10. The conveyor mechanism 70 includes conveying rollers 71 arranged at intervals in the conveying direction X, and a sprocket 73 fixed coaxially with the conveying roller 71 at one end in the width direction Y of each conveying roller 71. Each conveying roller 71 is rotatably supported at both ends by the fixed table 10. The second conveying unit 40D includes an endless roller drive chain 75 stretched across each sprocket 73, and a fourth drive source 77 that causes the roller drive chain 75 to rotate circumferentially. The fourth drive source 77 is composed of, for example, an electric motor capable of forward and reverse rotation. Figure 9 shows an example in which the fourth drive source 77, indicated by an arrow, is rotating forward. When the fourth drive source 77 rotates forward, the second conveying unit 40D can convey the first conveying unit 20A towards X1. When the fourth drive source 77 reverses direction, the second transport unit 40D can face the first transport unit 20A and transport to X2.

[0069] The operation of transporting the mold DE from the loading / unloading position 19 by the mold transport device 1D towards the mold placement area 117 of the injection molding machine 100 is as follows. The transport of the mold DE is started by rotating the first drive source 26 of the first transport unit 20A in the forward direction, or by rotating the fourth drive source 77 of the second transport unit 40D in the forward direction. When mold DE is transported to the target mold placement area 117, the operation of the first drive source 26 and the fourth drive source 77 of the conveyor mechanism 70 is stopped. Then, after attaching mold DE to the fixed mold platen 111 and the movable mold platen 113, the fourth drive source 77 of the second transport unit 40D is reversed until the movable table 41 moves to its initial loading / unloading position 19, thereby moving the movable table 41 back to its initial position at the start of transport. The first drive source 26 and the conveyor mechanism 70 are stopped until the transport of the next mold DE.

[0070] [Effects of mold transfer device 1D] The mold transport device 1D provides the same effects as the mold transport device 1A, except for the effect of transporting the mold DE by a chain drive mechanism, and also provides the following effects. By using the second conveying section 40D to which a conveyor mechanism is applied, thrust can be applied to the first conveying section 20A from multiple points in the conveying direction X, resulting in stable conveyance with less slippage and displacement, similar to the four-wheel drive system of an automobile. Furthermore, the second conveying section 40D can be constructed using inexpensive components and materials, thus keeping equipment costs low.

[0071] [Fourth modified example: Figure 10] The mold transport device 1E according to the fourth modified example includes, as shown in Figure 10, a first transport section 20B comprising a group of free-rotating rollers 81 on which the mold DE is placed, and a chain drive mechanism 85 that transports the mold DE placed on the group of free-rotating rollers 81 using a snake chain 86 that moves back and forth by a drive source. The second transport section 40A of the mold transport device 1E is the same as the previous one.

[0072] The free-rotating roller group 81 consists of multiple free-rotating rollers 83 rotatably mounted on the moving table 41, arranged in the conveying direction X. The axis of rotation of the free-rotating rollers 83 is along the width direction Y. The mold DE to be conveyed is placed on the free-rotating roller group 81.

[0073] The chain drive mechanism 85 comprises a snake chain 86, a fifth drive source 87 that engages with one end of the snake chain 86 and moves the snake chain 86 forward and backward, and a connecting piece 89 that is detachably attached to the mold DE provided at the other end of the snake chain 86. The connecting piece 89 is connected to the mold DE by fastening means such as bolts and nuts, adsorption means such as magnetism or suction, or pressing and fixing means such as claws.

[0074] The operation of transporting the mold DE from the loading / unloading position 19 by the mold transport device 1E toward the mold placement area 117 of the injection molding machine 100 is as follows. The transport of the mold DE is started by rotating the fifth drive source 87 of the first transport unit 20B in the forward direction to unwind the snake chain 86, and simultaneously rotating the second drive source 45 of the second transport unit 40A in the forward direction to unwind the snake chain 43. When mold DE is transported to mold placement area 117, the operation of the fifth drive source 87 and the second drive source 45 is stopped. Then, the connecting piece 89 of the second transport unit 40B is removed from mold DE, and after mold DE is attached to the fixed mold platen 111 and the movable mold platen 113, and until the connecting piece 89 retracts to the initial transport start position, the fifth drive source 87 and the second drive source 45 are reversed. The fifth drive source 87 and the second drive source 45 remain deactivated until the transport of the next mold DE.

[0075] [Effects of mold transfer device 1E] According to the mold transport device 1E, the same effects as the mold transport device 1A are achieved, except for the effect of transporting the mold DE by a chain drive mechanism, and in addition, the following effects are achieved. By using a chain drive mechanism 85 to push the back of the mold DE in the first transport section 20B, even tall molds can be prevented from lifting at the front end in the transport direction during acceleration or lifting at the rear end in the transport direction during deceleration, enabling stable and high-speed transport.

[0076] [Second Embodiment; Figures 11, 12, 13] Next, a second embodiment in which braking force is applied to the mold DE being transported between the fixed mold platen 111 and the movable mold platen 113 of the mold clamping device 110 will be described with reference to Figures 11 to 13. Here, the mold DE, which is transported to the clamping device 110 by the mold transport devices 1A to 1E, has inertia. By controlling this inertia, the mold DE can be positioned in the mold placement area 117 with high precision. Therefore, in the second embodiment, a mechanism (hereinafter referred to as the braking unit) that applies braking force to the transported mold DE is provided in the injection molding machine 100.

[0077] As shown in FIG. 11, the braking unit 130A enables a plurality of support rollers 119 provided in the mold clamping device 110 to rotate. For this purpose, the braking unit 130A includes, for example, an electric motor 131 and a roller drive chain 133 that orbits by the electric motor 131. The roller drive chain 133 receives the rotational driving force from the electric motor 131 and rotationally drives the support roller 119 via a sprocket (not shown). By adjusting the rotational speed of the electric motor 131, the rotational speed of the support roller 119 is controlled, and a braking force is applied to the mold DE placed on the support roller 119.

[0078] Now, in FIG. 11, the mold DE is being conveyed toward the mold clamping device 110 by the first conveying unit 20A and the second conveying unit 40A. At this time, the electric motor 131 of the braking unit 130A is operating, and the rotational speed of the support roller 119 is determined in consideration of the conveying speed V0 of the mold DE by the first conveying unit 20A and the second conveying unit 40A. That is, assuming that the virtual conveying speed of the mold DE due to the rotation of the support roller 119 is V1, when the support roller 119 receives the mold DE, the conveying speed V1 is made to coincide with the conveying speed V0 or approximated to the conveying speed V0. Preferably, the conveying speed V1 is made slightly slower than the conveying speed V0.

[0079] After the mold DE enters between the fixed mold plate 111 and the movable mold plate 113, the conveying speed V2 (<V1) of the mold DE due to the rotation of the support roller 119 is decelerated from the conveying speed V1, and the conveying speed V2 is set to zero so that the conveyance of the mold DE stops when the mold DE reaches the mold placement area 117. This control of the braking force is similarly applied to the braking units 130B to 130D shown in FIGS. 12 and 13. [[ID=j]]

[0080] As described above, by using the braking unit 130A to apply a braking force to the mold DE conveyed between the fixed mold plate 111 and the movable mold plate 113, the mold DE can be accurately positioned in the mold placement area 117.

[0081] Furthermore, when applying braking force to the mold DE being transported between the fixed mold platen 111 and the movable mold platen 113 by the support roller 119 to stop the mold DE in the mold placement area 117, it is preferable to accelerate the transport speed of the mold DE for a predetermined time just before it reaches the mold placement area 117 before stopping. This allows the mold DE, which has tilted forward due to inertia during deceleration, to be stopped quietly by instantly accelerating it to eliminate the forward tilt.

[0082] The above examples illustrate how braking force is applied to the underside of the mold DE via support rollers 119 on which the mold DE is placed. However, other means of applying braking force can be employed. For example, as shown in Figure 12(a), a braking unit 130B can be made from a fluid pressure cylinder mechanism comprising a cylinder 135, a piston rod 136, and a piston head 137. Alternatively, as shown in Figure 12(b), a braking unit 130C can be made from a ball screw mechanism comprising a ball screw shaft 141, a ball screw 143, and an electric motor 145 that rotates the ball screw 143. Furthermore, as shown in Figure 13, a braking unit 130D can be made from a snake chain 147 and an electric motor 149 that moves the snake chain 147 back and forth. Alternatively, instead of using the linear guides 42 of the mold transport devices 1A to 1C, or the free-rotating roller group 81 of the mold transport device 1E, a means of levitating the mold DE from the fixed table 10 can be used. This means could include, for example, high-pressure levitation, which involves spraying high-pressure air towards the fixed table 10, or magnetic levitation, which utilizes magnetism.

[0083] In addition to the above, it is possible to select or replace the configurations listed in the above embodiments, or to change them to other configurations as appropriate, as long as it does not deviate from the spirit of the present invention. for example, [Explanation of symbols]

[0084] 1A, 1B, 1C, 1D, 1E Mold transfer device 10 Fixed Tables 19. Loading / unloading locations 20A, 20B First Conveyor Unit 21 Conveyor rollers 23 sprocket 25 Roller drive chain 26 First drive source 27 Drive shaft 40A, 40C, 40C, 40D, 40E Second Conveyor Unit 41 Mobile Table 42 Linear Guide 42A Guide Plate 42B Guide Tip 43,147 Snake Chain 45 Second drive source 46 sprocket 50 Fluid pressure cylinder mechanism 51,135 cylinders 53,136 Piston Rods 55,137 Piston Heads 60 Ball screw mechanism 62,141 Ball screw shaft 63,143 Ball screw nuts 65,145 Electric motors 67 Transmission belt 70 Conveyor mechanism 71 Conveyor rollers 73 sprocket 75 Roller drive chain 77 Power source 81. Group of free-rotating rollers 83 Free-rotating roller 85 Chain drive mechanism 86 Snake Chain 87 Fifth drive source 89 Connecting piece 100 injection molding machine 110 Mold clamping device 111 Fixed board 113 Movable mold board 115 Tie Bar 117 Mold placement area 119 Support roller 120 Injection device 121 Heating cylinder 123 Injection Nozzle 130A,130B,130C,130D Braking part 131,149 Electric motors 133 Roller drive chain DE mold DE1 Fixed Mold DE2 Movable mold V20, V40 transport speed X Conveying direction Y width direction Z (height direction)

Claims

1. At least one set of molds, consisting of a fixed mold and a movable mold, is transported along the transport direction. A mold transport device that allows the following to occur: A first transport unit that transports the mold in the transport direction while the mold is placed on it, and a first drive source that drives the first transport unit in the transport direction, A second conveying unit that conveys the mold by moving the first conveying unit in the conveying direction, A second drive source, which is capable of being driven independently of the first drive source, drives the second transport unit in the transport direction, Equipped with, A mold conveying device characterized in that the conveying of the mold by the first conveying unit and the conveying of the mold by the second conveying unit can be performed independently of each other.

2. The first transport unit is, The rolling rollers consist of a rotating roller or a free-rotating roller on which the mold is mounted, If the rolling roller is the rotating roller, a drive mechanism for rotating the rotating roller is provided. The mold conveying device according to claim 1, wherein, when the rolling roller is the free-rotating roller, it is further provided with a drive mechanism for pushing the mold placed on the free-rotating roller in the conveying direction.

3. The drive mechanism for transporting the mold in the second transport section is: It consists of one of the following: a chain drive mechanism, a fluid pressure cylinder mechanism, and a rotary-to-linear motion conversion mechanism. A mold transport device according to claim 1 or claim 2.

4. If the transport speed of the mold by the first transport unit is V20 and the transport speed of the mold by the second transport unit is V40, The mold is transported with V20 < V40. The mold transport device according to claim 1.

5. From the start of transporting the mold to the end of transporting, The transport of the mold by the first transport unit and the transport of the mold by the second transport unit are performed in parallel, or The transport of the mold by the first transport unit and the transport of the mold by the second transport unit are performed selectively. The mold transport device according to claim 1.

6. When transferring the molds to the mold placement area between the fixed mold plate on which the fixed molds are attached and the movable mold plate on which the movable molds are attached, by one or both of the first and second transport units, The mold undergoes deceleration and acceleration, The mold transport device according to claim 5.

7. The mold being transported between the fixed mold plate on which the fixed mold is attached and the movable mold plate on which the movable mold is attached is equipped with a braking unit that applies a braking force in the opposite direction to the transport direction. The mold transport device according to claim 1.

8. The aforementioned braking unit is, Between the fixed mold plate and the movable mold plate, a braking force is applied so as to reduce the movement speed of the mold. The mold transport device according to claim 7.

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