KR100643607B1 - Elastic valve system for injection molding - Google Patents

Abstract

An elastic valve system for an injection mold is provided to prevent a valve pin from being damage or deformed by impact force applied to the valve pin during elevation of a piston, by arranging a buffering unit for stably absorbing impact force applied to the valve pin. An elastic valve system for an injection mold, comprises a buffering unit and a pin retreat adjustment unit(40). The buffering unit is arranged to buffer impact force to be transmitted to a valve pin(35), and includes a chamber(12ab), a flange(36), and a spring(15). The chamber is formed in the piston. The flange is arranged at one end of the valve pin positioned in the chamber. The spring is arranged at one side of the flange so as to elastically support the valve pin. The pin retreat adjustment unit variably controls the degree of retreat of the valve pin, and includes an elevation stopper(43) coupled onto a driving unit(10) through a screw so that the elevation stopper variably elevates in a vertical direction. The elevation stopper has a bottom surface contacting a top of the valve pin so as to restrict elevation of the valve pin.

Description

Elastic valve system for injection molding

1 is a cross-sectional view showing a valve device for an injection molding machine according to the prior art,

2 and 3 are cross-sectional views for explaining the gate opening and closing operation of the valve device for injection molding machine according to the present invention;

4 is a cross-sectional view illustrating a state in which the retraction amount of the valve pin is adjusted by the pin retraction amount adjusting means in the valve device for injection molding machine according to the present invention;

Figure 5 is an exploded perspective view for explaining the configuration of the pin retracting amount adjusting means according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: drive unit 11: cylinder

12: piston 13a, 13b: air channel

15: spring 20: manifold

20a, 30a: Resin Channel 30: Nozzle

31: gate 35: valve pin

36: flange 40: pin retraction amount adjusting means

40: casing 41: casing

42: rotator 43: elevating stopper

44: adjusting knob

The present invention relates to an injection molding machine for raising and lowering a valve pin by using the hydraulic pressure as the working pressure, and more particularly, to precisely control the injection amount by variably adjusting the retraction amount of the valve pin, thereby enabling mass production of high quality molded products. It relates to a valve device for an injection molding machine.

In general, an injection molding machine for molding a plastic product injects a water support material into a manifold from a mold cylinder in which resin is melted, and the injected resin is distributed evenly along a resin channel branched in the manifold to be coupled to the bottom of the manifold. It is a device that is supplied to each of the at least one nozzle and injected into the cavity of the mold, which is a product forming mold.

The injection molding machine is configured to open and close the gate by the lifting and lowering operation of the valve pin, and in the case of molding several pieces at a time according to the quantity of molded products, a manifold type that receives resin through a manifold is used, and a single product is produced. Single type is used when

1 is a cross-sectional view showing a valve device for an injection molding machine for raising and lowering the valve pin by using a high-pressure air as the operating pressure according to the prior art.

As shown in the related art, the conventional injection molding machine valve device includes a driving unit 100 and a valve device 200, and uses high pressure air as a driving source for the lifting operation of the valve pin 210.

That is, the driving unit 100 is formed with a plurality of air channels (110, 120) which is a pipe for supplying and discharging air of high pressure from the outside, and selectively through the plurality of air channels (110, 120) The piston 140 in the cylinder 130 moves up and down by the high pressure air flowing in. At this time, the lower end of the piston 130 has a structure in which the valve pin 210 is connected and interlocked.

In addition, the valve pin 210 is configured to selectively block or open a gate that forms the front end of the nozzle 220 by being elevated in conjunction with the piston 130.

On the other hand, the valve device 200 includes a nozzle 220 to which the heater is wound to prevent the solidification of the resin by forming an outer body, the valve pin 210 in the nozzle 220 in the vertical direction It is a structure that is installed to achieve lifting. Here, the nozzle 220 is a resin channel 230 is formed with a predetermined gap around the valve pin 210, both ends of the resin channel 230, the gate of the nozzle and the resin channel of the manifold 300 Each structure is connected to the 310.

In the valve device for injection molding machine configured as described above, when the high pressure working pressure is selectively supplied through the air channels 110 and 120, the piston 140 moves up or down, and at the same time, the valve pin 210 is interlocked with each other. The lifting operation is performed. Therefore, as the piston 140 is elevated, the gate of the nozzle is opened or shut off, and as a result, the resin supplied through the manifold 300 is supplied into the mold or blocked through the gate.

In summary, the valve gate device for the injection molding machine to operate the air pressure according to the prior art to raise the piston 140 by selectively supplying the high pressure air into the cylinder 130 through the corresponding air channels (110, 120), At this time, in conjunction with the piston 140, the valve pin 210 opens and closes the gate of the nozzle.

However, since the valve device according to the related art configured as described above uses high pressure air as an operation source for elevating the valve pin, it is necessary to adopt an airtight structure to prevent air leakage and a large pneumatic device for supplying the working pressure. As it requires a compressor, the structure is complicated by its volume, which is not only limited to the installation space but also has a disadvantage of extremely poor maintenance and management.

In addition, when applied to a multi-cavity mold having a plurality of nozzles, due to the dimensional dispersion of each nozzle, a deviation occurs in the injection amount of each nozzle, there was a problem that it is difficult to mass-produce a molded article having a uniform quality.

In order to solve such a problem, the applicant has applied for utility model registration No. 2002-09883 (Registration No. 0280604, registration decision), Utility Model Registration Application No. 2002-09884 (Registration No. 0280605, Registration Maintenance Decision), utility Application for registration of utility model No. 2002-09885 (registration No. 0280606, registration maintenance decision), application for utility model registration No. 2002-19175 (registration No. 0290456, registration maintenance decision), application for utility model registration No. 2003-0034932 (registration) No. 0341515 registration maintenance decision, Utility Model Registration Application No. 2003-0038360 (Registration No. 0344137 registration maintenance decision) has proposed a valve device for operating the valve pin in the vertical direction by the power source.

Looking at the configuration of these valve device roughly, it consists of a valve body and a drive means largely, the valve body is a resin flow path for injecting the resin into the mold through the gate provided at the front end is formed Take the general valve structure. As the driving means, a forward / reverse motor or an actuator for raising and lowering the valve pin by power supply is used.

In this way, the applicant's prior application of the valve device allows the size of the valve device to be reduced in size by employing a forward / reverse motor or an actuator as a driving source, thereby increasing the degree of freedom in mold design and increasing the amount of valve pin movement. Quick and precise control is possible.

However, since the present inventors have applied for a high-cost electronic device, the valve device is suitable for injection of precision molded products, but there is an economical inefficiency in injection of a simple molded product that does not require precision molding.

In addition, even when the resin channels of the manifold and the nozzle are precisely molded without dimensional dispersion, the manifold and the nozzle of the metal material are exposed for a long time due to the high temperature heat generated during the injection process, causing deformation, resulting in uneven injection amount. There was a problem of reworking.

On the other hand, the present applicant has filed a "injection molding machine with an injection pressure control device" to Patent Application No. 10-2005-0002522 in order to solve the above problems.

The injection molding machine equipped with the injection pressure adjusting device, which the applicant has previously applied, allows to uniformly control a plurality of nozzle injection amounts through a configuration of additionally mounting a resin pressure adjusting means capable of variably adjusting the diameter on the resin channel.

However, the injection molding machine, which the applicant has filed in advance, has a disadvantage in that it is difficult to apply because the space is narrow when it is mounted on a valve device used for producing a relatively small precision molded article.

That is, because the resin flows along the resin channel under high pressure, one end of the nozzle or manifold in which the injection pressure control device is configured requires high watertightness, and for this, a complex watertight structure must be adopted to reduce maintenance and freedom of design. There was a problem that is greatly limited.

In addition, there was a drawback of being deformed or damaged by an impact force imparted to the valve pin in the vertical direction when the piston was raised and lowered, resulting in an increase in maintenance cost and a decrease in productivity.

The present invention has been made to solve the above problems, the present invention by precisely controlling the opening amount of the gate by varying the retraction amount of the valve pin according to the processing deviation of each nozzle or manifold in the multi-cavity mold It is an object of the present invention to provide a valve device for an injection molding machine that can quickly compensate for non-uniform injection quantity and increase the degree of freedom of processing of the nozzle and the manifold.

Another object of the present invention is to provide a valve device for an injection molding machine that can prevent the damage and deformation caused by the lifting impact force applied to the valve pin to increase the life and reliability of the device.

In the valve device for injection molding machine according to the present invention for realizing the above object, an air channel for supplying and discharging a high-pressure operating pressure is connected to the inner cylinder and selectively lifted by the operating pressure in the cylinder. A manifold in which a piston is provided, a manifold in which a branched resin channel through which molten resin is moved, and a resin channel coupled to a lower surface of the manifold, are installed at a lower side of the driving unit, and the resin channel receives a resin from the gate of the distal end. In the center is provided with a valve pin for opening and closing the gate in conjunction with the piston in the center, the valve pin is a valve device for an injection molding machine comprising a nozzle that the upper end is provided to protrude to the upper side of the drive unit,

Compensation for the lifting impact force transmitted to the valve pin is provided on one side of the flange and the flange is formed in the form of the diameter is extended to the chamber formed in the piston and one end of the valve pin located in the chamber and the elastic support Spring buffer means for doing; The variable amount of retraction of the valve pin by variable screw vertically by the screw fastening to the upper side of the drive and the pin retracting amount adjusting means having a lifting stopper having a lower surface in contact with the upper end of the valve pin to limit the rise It is characterized by including the configuration.

As a preferable feature of the present invention, the pin retracting amount adjusting means includes a casing fixedly installed at an upper side of the driving unit, and a screw hole rotatably provided inside the casing, and having a lifting stopper screwed vertically at the center thereof. The rotator is formed, and one end of the worm gear is engaged with the outer circumferential surface of the rotator, and the other end is formed of an adjusting knob that protrudes out of the casing to receive a manipulation force of the operator.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are consistent with the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain the invention in the best way. It must be interpreted as meaning and concept.

Hereinafter, a preferred embodiment of a valve device for an injection molding machine according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a cross-sectional view showing a valve pin in a lower state, that is, a state of blocking the gate in the valve device for injection molding machine according to the present invention, Figure 3 is a cross-sectional view showing a state in which the valve pin is raised, that is, the gate is opened. to be. And, Figure 4 is a cross-sectional view for explaining a state in which the retraction amount of the valve pin is adjusted by the pin retraction amount adjusting means in the valve device for injection molding machine according to the present invention.

Finally, Figure 5 is an exploded perspective view for explaining the configuration of the pin retraction amount adjusting means according to the present invention.

As shown therein, the valve apparatus for injection molding machine of the present invention includes a drive unit 10 for selectively raising and lowering the piston 12 by receiving an operating pressure, and located below the drive unit 10 and melted therein. The manifold 20 is formed on the bottom of the manifold 20 is formed in the manifold 20 is formed in the branched resin channel 20a so that the resin in the state can be moved, it is configured to be injected into the mold The upper end portion is provided in the nozzle 30 and the inside of the nozzle 30 and protrudes upward of the driving unit 10 through the piston 12, which is an inlet of the nozzle 30 in cooperation with the piston 12. It is a structure including a valve pin 35 for selectively opening and closing the gate 31. At this time, the gate 31 is tapered in a shape in which the diameter is narrowed downward.

On the other hand, the driving unit 10 for providing a lifting force for lifting the valve pin 35 is connected to a plurality of air channels (13a, 13b) for supplying and discharging the operating pressure of the high pressure air or hydraulic pressure from the outside is formed A cylinder 11 connected to the air channels 13a and 13b is formed therein.

And the inside of the cylinder 11 is a structure that is provided with a piston 12 which is selectively lifted by the operating pressure introduced, the lifting structure of the piston 12 can be implemented by a variety of known techniques detailed description Is omitted.

On the other hand, the piston 12 has a structure in which the valve pin 35 for opening and closing the gate 31 of the nozzle 30 is connected and interlocked.

The manifold 20 in which the branched resin channel 20a was formed is provided in the lower part of the drive part 10 comprised in this way, The lower surface of this manifold 20 is provided in the branched resin channel 20a. The corresponding nozzles 30 are coupled to each other to receive the resin.

The nozzle 30 is a member of a length member having a tubular shape in which the lower end portion, that is, the portion in which the gate 31 is located, is tapered to have a small diameter, and a resin channel 30a is formed at an inner center thereof. The resin channel 30a is connected to the gate 31 which is formed integrally with the tip portion of the nozzle 30 or is processed separately. In this case, although not shown, the gate 31 is a structure connected to one end of a mold for molding an injection molded product, and the resin flowing along the resin channel is solidified (hardening phenomenon) to the outer surface of the nozzle 30. The heater wire (unsigned) for winding is prevented.

On the other hand, the nozzle 30 is provided with a valve pin 35 having a smaller diameter than the inner diameter of the resin channel (30a) formed in the center, the valve pin 35 is the piston of the drive unit 10 described above ( The gate 31 is opened and closed by being lifted in conjunction with 12).

The configuration as described above is similar to that of the conventional injection molding machine. However, the present invention buffers and absorbs the impact force applied to the valve pin when the piston is raised and lowered to prevent deformation and breakage of the valve pin, and the variable amount of retraction of the valve pin to variably adjust the maximum injection amount of the nozzle It is characterized in that it comprises a pin retracting amount adjusting means for uniformly controlling the injection amount of a plurality of nozzles mounted on the multi-cavity mold by controlling the independent.

The shock absorbing means includes a chamber 12a formed in a direction perpendicular to the interior of the piston 12, a flange 36 provided on the valve pin 35 having one end positioned in the chamber 12a, and the flange 36. It is provided on the lower side of the valve pin 35 is composed of a spring (15) for applying a rising elastic force.

The chamber 12a is a kind of space formed inside the piston 12, and is configured such that one end of the valve pin 35 passes and a spring 15 is interposed therein. The piston 12 in which the chamber 12a is formed is provided with a through hole (unsigned) in the upper and lower center thereof so that the valve pin 35 can pass.

The valve pin 35 is a member of a length member having a predetermined length, the lower end of which is located at the gate 31 side, and the upper end thereof is configured to protrude upward of the driving unit 10 as shown in the drawing. The valve pin 35 is formed with a flange 36 having a form in which a diameter is expanded at one end of the piston 12 located in the chamber 12a. On the other hand, the valve pin 35 is preferably formed in one member as shown in the drawing, but may be used in combination by dividing it into two or more for convenience in processing.

The spring 15 is interposed below the flange 36 of the valve pin 35, and acts a lifting elastic support force on the flange 36 to raise the valve pin 35. The valve pin 35 receiving the elastic support of the spring 15 maintains the upper surface of the flange 36 in contact with the inner upper surface of the chamber 12a.

The shock absorbing means configured as described above performs a shock absorbing function to absorb and cushion the impact force received in the process of raising and lowering the valve pin 35 integrally when the piston 12 is lifted in the cylinder 11.

The pin retraction amount adjusting means is for controlling the amount of resin passing through the gate 31 by limiting the retraction amount of the valve pin 35, and the casing 41, the rotator 42, the lifting stopper 43, and the adjustment are large. It consists of a knob 44.

That is, the pin retracting amount adjusting means 40 is provided with a casing 41 is fixed to the upper side of the drive unit 10, the casing 41 is formed with a through hole (unsigned) in a direction perpendicular to the center will be described later In order to prevent rotation of the elevating stopper 43, a part of the through hole has a rectangular structure such as a square.

In addition, the inside of the casing 41 is a configuration in which the rotator 42 is rotatably installed while preventing flow in the up and down directions. The rotator 42 has a structure in which an outer circumferential surface is processed in the form of a worm wheel, and a center portion thereof is screwed to have a displacement in a vertical direction in which a lifting stopper 43 to be described later is formed through a screw hole.

The rotator 42 is selectively rotated in one direction or the reverse direction in conjunction with the control knob 44 receives the operator's operating force.

The adjusting knob 44 is a member of a length member having a predetermined length, one end of which is formed of a screw-shaped gear having a plurality of spirals on the outer circumferential surface corresponding to the outer circumferential surface of the rotator 42 so as to be mated with a worm gear method. The other end is protruded to the outside of the casing 41 and the notch is formed on the outer circumferential surface so that the operator can rotate by hand, or the cross groove is formed so that it can be rotated using a tool such as a driver. The adjusting knob 44 is preferably supported through a bearing support, which is a conventional shaft support, to perform stable rotation while preventing flow in the up, down, left, and right directions.

The elevating stopper 43 is a member of a length member which is screwed to the screw hole of the rotator 42 described above. The lifting stopper 43 is provided to be able to move in the up and down direction in conjunction with the rotation of the rotator 42 while preventing the rotation thereof. .

That is, the lifting stopper 43 is screwed so that the upper outer circumference is screwed to the rotator 42, the lower outer circumference is fitted to one side of the through hole of the casing 41 so that the cross section has a square structure. Rotation is prevented.

The lifting stopper 43 is to limit the amount of movement of the valve pin 35 as a result of the lower surface is selectively contacted with the upper end of the valve pin (35).

The pin retracting amount adjusting means 40 configured as described above rotates the adjusting knob 44 in one direction or the reverse direction so that the rotator 42 rotates, and at the same time, the lifting stopper screwed to the rotator 42 43) rises or falls in the vertical direction. Therefore, the opening position of the gate 31 of the valve pin 35 which is in contact with the lower surface of the elevating stopper 43 and the upward movement is limited can be adjusted.

On the other hand, in the present invention, the pin retracting amount adjusting means 40 is configured by the worm gear biteing method in order to easily transmit the operator's operating force, but when the installation space is narrow, the lifting stopper is directly screwed to the casing that is a fixed support, although not shown By fastening in a manner to simplify the configuration, the upper end of the elevating stopper may be configured in a manner to rotate by using a tool by processing in the form of the head of the bolt.

Referring to the operation of the valve device for injection molding machine of the present invention configured as described above are as follows.

First, in the initial state in which the injection molding machine is not operated as shown in FIG. 2, the piston 12 and the valve pin 35 are lowered to maintain a state of blocking the gate 31.

When the operating pressure is supplied to the air channel 13b in this state, the valve pin 35 having one end elastically supported in the chamber 12a formed therein while the piston 12 in the cylinder 11 makes an upward movement. ) Will also move upward as a whole. At this time, the valve pin 35 is stopped by the upper end thereof by contacting the lower end of the lifting stopper 43 of the pin retracting amount adjusting means 40, so as a result, the gate 31 remains open. Allow injection to be carried out.

Here, the valve pin 35 is transmitted to the impact force generated when the contact with the lifting stopper 43 in the ascending process, the impact force is a spring 15 for elastically supporting the lower side of the flange 36 of the valve pin 35 Is absorbed and buffered.

Subsequently, when the injection is completed, the piston 12 is lowered by switching the supply pressure to the air channel 13a located at the upper side while the operating pressure supplied to the air channel 13b at the lower side is cut off. The valve pin 35 supported by the spring 15 in the interior of 12 is also integrated to descend. At this time, the lowering operation is completed by the piston 12 is in contact with one side of the cylinder 11, at this time the valve pin 35 forms a position that the lower end blocks the gate 31.

Here, the valve pin 35 is transmitted to the impact force generated when the piston 12 is in contact with the cylinder 11 in the lowering process, the impact force is by the spring 15 provided on one side of the valve pin 35 Absorption buffer.

On the other hand, the valve device for injection molding machine of the present invention can variably adjust the maximum retraction amount of the valve pin 35 using the pin retraction amount adjusting means 40, through which the opening amount of the gate 31 can be adjusted. .

That is, when one end of the adjustment knob 44 provided on the upper side of the drive unit 10 is rotated one direction or the opposite direction by a predetermined angle, the rotator 42 engaged in the worm gear method at the other end to the adjustment knob 44 is interlocked in one direction. Or reverse rotation. At this time, the lifting stopper screwed to the center of the rotator 42 is moved in the direction of rising or falling by the rotation of the rotator 42. Accordingly, the opening amount of the gate 31 can be adjusted by arbitrarily adjusting the rising position of the valve pin 35 which is in contact with the lower surface of the elevating stopper 43 and the upward movement is limited.

For example, when the lifting stopper 43 is adjusted to be lowered as shown in FIG. 4, the maximum lift position of the valve pin 35 in contact with the lower surface of the lifting stopper 43 becomes lower than in FIG. 3. In other words, the lower upward position of the valve pin 35 is lowered, so that the lower end of the valve pin 35 does not completely open the tapered gate 31, thereby reducing the amount of resin passing through.

The pin retracting amount adjusting means 40 acting as described above can be independently mounted to each nozzle 30 to precisely adjust the amount of resin of the corresponding nozzle 30, and as a result, the plurality of nozzles 30 mounted on the multi-cavity mold. ) The injection quantity can be set under the same conditions.

It is apparent to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and changes can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations will have to belong to the claims of the present invention.

The valve device for injection molding machine configured and operated as described above can precisely control the opening amount of the gate by variably adjusting the retraction amount of the valve pin exposed to the upper side of the driving part, so that the resin of various nozzles applied to the cavity The injection quantity can be independently calibrated to improve the quality of the molded products, and it is possible to improve the maintainability and the reliability of the machine because it does not require complicated watertight structure while realizing the simplification of the composition compared to the past. to provide.

In addition, the shock force applied to the valve pin during the lifting and lowering of the piston is absorbed and buffered stably through the buffer means to prevent breakage and deformation of the valve pin due to the lifting impact force. Therefore, it provides an advantage that can solve the problems such as increase in maintenance costs due to breakage and deformation of the valve pin, and productivity decrease due to equipment downtime.

Claims (2)

An air channel for supplying and discharging a high-pressure operating pressure is connected to an inner cylinder, and the cylinder is installed at a lower side of the driving unit and has a piston which is selectively lifted by the operating pressure. A manifold in which branched resin channels through which resin is formed is formed, and a resin channel coupled to a lower surface of the manifold to receive a resin is connected to a gate of the front end thereof, and a valve pin is provided at the center to open and close the gate by interlocking with a piston. In the valve device for injection molding machine comprising a nozzle, the valve pin is provided so that the upper end is extended to the upper side of the drive unit, Compensation for the lifting impact force transmitted to the valve pin is provided on one side of the flange and the flange is formed in the form of the diameter is extended to the chamber formed in the piston and one end of the valve pin located in the chamber and the elastic support Spring buffer means for doing; A pin retraction amount adjusting means having a lifting stopper that vertically variably moves up and down by screwing on an upper side of the driving part to variably adjust the retraction amount of the valve pin and the lower surface contacts an upper end of the valve pin; Valve device for injection molding machine comprising a. According to claim 1, The pin retracting amount adjusting means, A casing fixedly installed at an upper side of the driving unit; A rotator rotatably provided in the casing and having a screw hole in which a lifting stopper is vertically screwed; An adjustment knob that has one end engaged with a worm gear on the outer circumferential surface of the rotator and the other end protrudes out of the casing to receive a manipulation force; Valve device for injection molding machine, characterized in that consisting of.

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