Patent Application
20060051445
The present invention relates generally to injection molding, and more particularly to injection molding systems using pre-assembled molds that can be installed into a standardized, reusable mold base.
In a typical injection molding system, one or more materials (such as molten plastic or metal) are injected into a mold in order to form a molded part. The mold includes one or more molding chambers for receiving the injected material(s). After a material is injected, the material is typically allowed to set for some period of time, after which another material may be injected. When the molded part is complete, the molded part is ejected from the mold, for example, by externally actuating various ejector components that are built into the mold.
Thus, an injection molding machine typically includes at least an injection mechanism for causing injection of one or more materials into a mold and an ejection mechanism for ejecting the molded part (e.g., by activating the ejector components in the mold). Conceptually, the mold fits into the injection molding system between the injection mechanism and the ejection mechanism.
The mold typically includes two separate sections, each defining a portion of each molding chamber. One of the mold sections may be fixedly mounted within the injection molding machine, while the other mold section is movably mounted within the injection molding machine. During molding, the two sections are typically forced into contact with one another to form the molding chamber(s), for example, by forcing the movably mounted mold section against the fixedly mounted mold section. After the mold sections are in contact, the material(s) can be injected into the molding chamber(s).
As known in the art, each of the mold sections may be composed of multiple interconnected modules. For example, as described in published PCT application number WO 03/031141 A1 (hereinafter referred to as the “Persson PCT application”), a first mold section may include a first mold module, a drive module, and a distributing module, while a second mold section may include a second mold module, an ejector module, an engaging module, and a guide module. The first mold section may be fixedly mounted within the injection molding machine and the second mold section may be movably mounted in the injection molding machine, in which case the second mold section may be moved into contact with the first mold section in order to form one or more mold chamber(s) for the injection molding process. The engaging module, together with an outer locking means, locks the second mold module against the first mold module and absorbs the forces which act to separate the first and the second mold modules from each other during the injection molding process. The guide module supports the second mold module, the ejector module, and the engaging module to ensure that they move in a suitable fashion in relation to the first mold section. Multiple-part molds are also discussed in U.S. Pat. Nos. 4,274,617; 5,837,086; and 6,652,263.
The ejection mechanism may include a replaceable ejector plate packet. Published German patent application number DE10059045 describes an injection molding machine having a replaceable ejector plate packet that is attached to a base ejector plate packet by a bolt with a flange that cooperates with a curved recess at the base of a cross-bar fitted into a slot in the base packet.
The ejection mechanism may include an actuator that is directly or indirectly coupled to the ejector components of the mold and is hydraulically operated to actuate the ejector components of the mold. In injection molding machines that do not include a hydraulically-operated actuator, the ejector components of the mold may be actuated in other ways. For example, a portion of the mold may be moved within the injection molding machine so as to engage the ejector components of the mold with an ejection actuator that is fixedly attached to the injection molding machine. Such an injection mechanism can be implemented using a HASCO(R) guided ejector pull back device (part number Z165) that is incorporated into the movable portion of the mold and a HASCO(R) ejector rod (part number Z166) that is fixedly attached to the injection molding machine. In order to eject the molded part from the mold, the movable portion of the mold may be moved so that the guided ejector pull back device engages with the ejector rod, thereby actuating the ejector components of the mold.
All of the above-referenced patents and patent applications are hereby incorporated herein by reference in their entireties.
In accordance with one aspect of the invention, a unitary mold for an injection molding system is composed of a number of interconnected modules. Compared to the two-part mold described in the Persson PCT application, a unitary mold of the present invention does not require an engaging module, a guide module, and outer locking means in order to move and hold two mold sections together for injection molding. Furthermore, a unitary mold of the present invention is typically easy to install and remove with little tooling. Also, by pre-assembling the entire mold, all components are protected against damage, and no parts are omitted by mistake.
In accordance with another aspect of the invention there is provided an injection molding system including an injection molding machine and a modular mold that is assembled prior to installation in the injection molding machine. The injection molding machine and the mold interface through standardized injection and ejection interfaces.
The injection molding machine typically includes an active ejection mechanism. The mold typically includes integral ejector components that are actuated by the ejection mechanism. The ejection mechanism may be coupled to the integral ejector components through a quick-connect mechanism. Typically, the injection molding machine includes a first portion of the quick-connect mechanism (e.g., on an ejector clamp plate), and the mold includes a second portion of the quick-connect mechanism (e.g., on a clamping plate).
In an exemplary embodiment, the first portion of the quick-connect mechanism comprises a male part, and the second portion of the quick-connect mechanism comprises a female part that engages the male part. The female part typically includes a positive locking feature for securing the male part during deployment and retraction of the integral ejector components. The male part typically includes a floating mechanism allowing the mold to move relative to the injection molding machine when the mold is locked into the injection molding machine.
In accordance with another aspect of the invention there is provided an injection molding machine configured to receive a pre-assembled modular mold. The injection molding machine and the mold interface through standardized injection and ejection interfaces.
The injection molding machine typically includes an active ejection mechanism that is coupled to integral ejector components in the mold through a quick-connect mechanism. Typically, the injection molding machine includes a first portion of the quick-connect mechanism (e.g., on an ejector clamp plate), and the mold includes a second portion of the quick-connect mechanism (e.g., on a clamping plate).
In an exemplary embodiment, the first portion of the quick-connect mechanism comprises a male part, and the second portion of the quick-connect mechanism comprises a female part that engages the male part. The female part typically includes a positive locking feature for securing the male part during deployment and retraction of the integral ejector components. The male part typically includes a floating mechanism allowing the mold to move relative to the injection molding machine when the mold is locked into the injection molding machine.
In accordance with another aspect of the invention there is provided apparatus in the form of a plate that is attachable to an injection molding machine for interfacing the injection molding machine with a pre-assembled modular mold. The plate and the mold interface through a standardized ejection interface. The standardized ejection interface may include a quick-connect mechanism for coupling an active ejection mechanism of the injection molding machine with integral injector components in the mold. The plate includes a first portion of the quick-connect mechanism for cooperation with a second portion of the quick-connect mechanism in the mold.
In an exemplary embodiment, the first portion of the quick-connect mechanism comprises a male part, and the second portion of the quick-connect mechanism comprises a female part that engages the male part. The male part is positively locked into the female part for deployment and retraction of the integral ejector components. The male part typically includes a floating mechanism allowing the mold to move relative to the injection molding machine when the mold is locked into the injection molding machine.
In accordance with another aspect of the invention there is provided a pre-assembled mold having a plurality of modules interconnected to form a unitary mold for use in an injection molding machine. The injection molding machine and the mold interface through standardized injection and ejection interfaces. The plurality of interconnected modules includes at least a first mold module defining a first portion of a mold chamber and a second mold module defining a second portion of the mold chamber. The mold may also include a support module for supporting at least one of the first mold module and the second mold module. The mold may also include a return housing module containing integral ejector components that are actuated by an active ejection mechanism in the ejection molding machine. The ejection mechanism may be coupled to the integral ejector components through a quick-connect mechanism, in which case the injection molding machine may include a first portion of the quick-connect mechanism and the mold may include a second portion of the quick-connect mechanism. The mold may include a clamping module for locking the mold into the injection molding machine, the clamping module including the second portion.
In accordance with another aspect of the invention there is provided an injection molding method involving providing a pre-assembled modular mold; securing the mold in an injection molding machine; injecting at least one material into the mold to form a molded part; and ejecting the molded part from the mold. The injection molding machine and the mold interface through standardized injection and ejection interfaces. A quick-connect mechanism may be used to couple an active ejection mechanism of the injection molding machine with integral ejector components of the mold. The injection molding machine may include a first portion of the quick-connect mechanism, and the mold may include a second portion of the quick-connect mechanism. Securing the mold in the injection molding machine may involve aligning the first portion and the second portion. The first portion may include a male part, and the second portion may include a female part that engages the male part, in which case securing the mold in the injection molding machine may involve aligning the female part with the male part.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
In the accompanying drawings:
In accordance with embodiments of the present invention, an injection molding system includes an injection molding machine that receives, or is outfitted to receive, one or more full-assembled injection molds. The injection molding machine typically includes an injection mechanism for injecting one or more materials into the mold and an ejection mechanism for ejecting a molded part from the mold. The molds preferably interface with the injection mechanism of the injection molding machine through a runner clamp plate that includes a runner system for conveying injection molding material to the mold and with the ejection mechanism of the injection molding machine through an ejector clamp plate. The runner clamp plate and the ejector clamp plate can be integral components of the injection molding machine or can be separate components that are attached or otherwise installed in the injection molding machine. The runner clamp plate and the ejector clamp plate are preferably “universal” in that they can interface with molds having different internal geometries and include standard runner and ejection interfaces between the injection molding machine and the molds.
In preferred embodiments of the present invention, a universal mold base, including the runner clamp plate and the ejector clamp plate, is installed into the injection molding machine for receiving molds. The runner clamp plate is typically attached to a fixed machine plate of the injection molding machine, and the ejector clamp plate is typically attached to a movable machine plate of the injection molding machine. The mold base can be configured to support one or more molds at a time. For example, the mold base can be configured to support one, two, four, or eight molds simultaneously. When installed into the injection molding machine, the mold base can be considered part of the machine as opposed to part of the mold.
In preferred embodiments of the present invention, the molds are modular, and include a series of interconnected modules or plates. In a typical configuration, each mold includes, in order, a cavity block that interfaces with the runner clamp plate and includes various geometry-dependent components for the molded part, a core block that includes additional geometry-dependent components for the molded part, a support plate to provide added stiffness to the core block, a return housing plate that includes components for ejecting the molded part, and a clamping plate that interfaces with the ejector clamp plate.
In preferred embodiments of the present invention, a quick-connect mechanism is used to couple the ejector components of the mold to an ejector component of the ejector clamp plate (described below). The quick-connect mechanism typically includes an elongated (male) part that is attached or integral to the ejector clamp plate and a corresponding receptacle (female) part that is attached or integral to the mold, and, more specifically, to the clamping plate of the mold. The female part is coupled to the ejector components in the mold (typically an ejector plate) for deploying and retracting the ejector components, specifically in response to movement of the male part by the injection molding machine. The female part typically includes a positive locking mechanism that interfaces with a corresponding notch or channel in the male part, so that the mold locks onto the ejector clamp plate when the male and female parts interface with one another. The quick-connect mechanism typically includes a floating mechanism that allows for movement of the mold relative to the ejector clamp plate within predetermined tolerances when the mold is locked onto the ejector clamp plate (e.g., to aid in aligning the mold with the runner clamp plate). The quick-connect mechanism typically includes an automatic release for releasing the male part from the female part following retraction of the ejector components. Once the mold is positioned onto the ejector clamp plate, the mold is typically secured with a number of bolts.
As discussed above, in preferred embodiments of the present invention, the runner clamp plate 1 and the ejector clamp plate 2 are components of a mold base that is installed into the injection molding machine.
As discussed above, in preferred embodiments of the present invention, the molds are modular, and include a series of interconnected modules or plates. The molds are preferably pre-assembled so that the unitary mold can be placed into the mold base. Among other things, such pre-assembly helps to reduce the likelihood of damage to the mold components and the likelihood of omitting a mold component.
The procedure for installing a mold into the mold base is now described.
The male part 19 of an exemplary quick-connect mechanism is now described.
The female part of an exemplary quick-connect mechanism is now described.
In order to lock the ejector mechanism of the injection molding machine with the internal ejector components of the mold 3, the male part 19 is engaged with the female part 18.
In order to eject the molded part from the mold 3, the male part 19 is pushed forward by the ejection mechanism of the injection molding machine, which in turn causes deployment of the ejection actuator 30 via the ejector component interface 95.
As discussed above, the runner clamp plate 1 and the ejector clamp plate 2 (and therefore the mold base 100) can be configured to support one, two, or more molds.
After the molds are installed in the injection molding machine, the molding material can be injected into the molds. The material is allowed to set for some period of time, after which the molded parts are ejected from the molds. This is typically accomplished through hydraulic operation of the male parts 19. Specifically, with reference again to
One general problem in injection molding systems is deformation of the mold caused by the force of the material as it is being injected. Such deformation typically depends on, in part, the size and placement of the opening of the ejection mechanism located in the return housing plate 16. Therefore, in preferred embodiments of the present invention, the molding chamber(s) and related components, such as the ejection mechanism in the return housing plate 16, are placed off-center and are substantially aligned. This alignment of the ejection mechanism with the molding chamber(s) generally allows the size of the opening to be reduced, which in turn helps to reduce the amount of deformation during injection molding.
It should be noted that, while the portions of the quick-connect mechanism are preferably located on clamping plate and the ejector clamp plate, alternatively the portions of the quick-connect mechanism could be located elsewhere on the mold and the injection molding machine. For example, the machine portion of the quick-connect mechanism could be located on the runner clamp plate 1, in which case the mold portion of the quick-connect mechanism could be located on the cavity block 13. Thus, the present invention is not limited to the position of the portions of the quick-connect mechanism.
It should also be noted that, while preferred embodiments include one and only one quick-connect mechanism for each mold, alternatively there could be multiple quick-connect mechanisms for each mold. Thus, the present invention is not limited to a particular number of quick-connect mechanisms for each mold.
The present invention may be embodied in other specific forms without departing from the true scope of the invention. The described embodiments are to be considered in all respects only as illustrative and not restrictive.
