Mold unit and injection molding machine

Abstract

To provide a die unit and an injection molding machine that have a simple configuration, perform molding work after surely returning a placed core to a die, and do not damage the die.SOLUTION: An injection molding machine 10 has control means 80 that controls operation of the injection molding machine and is connected to detection means and negative pressure means, wherein the control means 80 closes a first air passage 52a and a second air passage 53f when the placing core 60 is located in a recess part when molding of a molded product F is completed and a movable die 52 is separated from a fixed die 51, and enables the movable die 52 to operate when the detection means detects a predetermined air pressure.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a mold unit in which an undercut is placed and a core is used for molding, and an injection molding machine using the same. [Background technology]

[0002] Patent Document 1 describes a simplified molding die, according to which the simplified injection molding die is composed of a fixed die, a movable die, and a core insert, and is configured to mold a molded product by filling a closed mold space formed by the fixed die, the movable die, and the core insert with molten resin, and then cooling and solidifying it. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-205679 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the above-mentioned simplified molding die, when the molded product is ejected, the placement core is removed from the die together with the molded product by the ejector pin and is then manually returned to the die.

[0005] To confirm whether the core has been returned reliably, it is possible to compare a reference image with the real-time image, but there is a risk that the accuracy of the judgment will be reduced due to differences in the amount of light that hits the image due to the time difference between the reference image and the real-time image.

[0006] It is also possible to use a touch sensor, but this would reduce the accuracy of the judgment due to thermal expansion of the mold and the placed core, and would require wiring, which could complicate the configuration.

[0007] For the reasons described above, if molding operations were performed when the placed core had not yet fully returned to the mold, there was a risk that interference would occur when the mold was closed, causing damage to the mold.

[0008] The present invention provides a mold unit and an injection molding machine which have a simple configuration, can reliably return a placed core to a mold, and then perform molding operations without damaging the mold. [Means for solving the problem]

[0009] The invention of claim 1 provides a mold unit for use in an injection molding machine, which molds a molded product by injecting molten resin into a product molding section formed by a fixed mold, a movable mold that moves toward and away from the fixed mold, and a core placed in the fixed mold and / or the movable mold, comprising: The die unit includes the fixed die, the movable die, and the placement core, The fixed side mold and / or the movable side mold in which the placement core is disposed include: a recessed portion is provided so as to open toward the product molding portion, and a first air passage through which air can flow and a second air passage through which air can flow are provided at a position different from the first air passage so as to communicate with the recessed portion, the placing core is formed to be movable within the recess and is capable of simultaneously closing the first air passage and the second air passage, the second air passage is connected in this order to a detection means for detecting an air pressure in the second air passage and a negative pressure means for putting the second air passage into a negative pressure state; In an assembled state, the detection means is connected to a control means for controlling the operation of the injection molding machine, When molding of the molded product is completed and the movable mold is separated from the fixed mold, the placed core is positioned in the recess to close the first air passage and the second air passage, and when the detection means detects that a predetermined air pressure is reached, a signal to enable the movable mold to operate is output to the control means.

[0010] According to this, the first air passage and the second air passage are closed by the placed core, and the detection means detects that the air pressure is at a predetermined level, thereby making it possible to return the placed core reliably to the mold with a simple configuration and perform molding work, thereby creating a mold unit that does not damage the mold.

[0011] Further, an ejector capable of sending out the placed core toward the product molding section can be disposed in the first air passage.

[0012] According to this, the first air passage also functions as a passage in which the ejector is disposed, which leads to a simple configuration.

[0013] According to a third aspect of the present invention, there is provided an injection molding machine for molding a molded product by injecting molten resin into a product molding section formed by a fixed mold, a movable mold that moves toward and away from the fixed mold, and a core placed in the fixed mold and / or the movable mold, a recessed portion opening toward the product molding portion is provided in the fixed mold and / or the movable mold in which the placement core is disposed, and a first air passage through which air can flow and a second air passage through which air can flow are provided at a position different from the first air passage so as to communicate with the recessed portion, the placing core is formed to be movable within the recess and is capable of simultaneously closing the first air passage and the second air passage, the second air passage is connected in this order to a detection means for detecting an air pressure in the second air passage and a negative pressure means for putting the second air passage into a negative pressure state; a control means for controlling the operation of the injection molding machine and connected to the detection means; When the molding of the molded product is completed and the movable mold is separated from the fixed mold, the control means positions the placing core within the recess to close the first air passage and the second air passage, and when the detection means detects that a predetermined air pressure is reached, makes the movable mold operable.

[0014] According to this, an injection molding machine that exhibits the effects of the mold unit recited in claim 1 can be obtained.

[0015] Further, an ejector capable of sending out the placed core toward the product molding section is disposed in the first air passage.

[0016] According to this, an injection molding machine that exhibits the effects of the mold unit recited in claim 2 can be obtained.

[0017] Further, the negative pressure means and the detection means are disposed outside the fixed die and / or the movable die in which the placing core is disposed.

[0018] According to this, the negative pressure means and the detection means can be removed from the fixed mold and / or the movable mold for maintenance, which makes it possible to facilitate maintenance management.

[0019] In addition, a filter is disposed between the second air passage and the detection means.

[0020] According to this, the filter can prevent problems caused by dirt on the negative pressure means and the detection means. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic side view of an injection molding machine according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a block diagram illustrating a main part of the embodiment. [Diagram 3] 2 is an explanatory diagram showing an operating state of a main part of the injection molding machine of the embodiment. FIG. [Figure 4] FIG. 4 is an explanatory diagram showing a continued operating state from FIG. 3; [Diagram 5] FIG. 5 is an explanatory diagram showing a continued operating state from FIG. 4. [Figure 6] FIG. 6 is an explanatory diagram showing a continued operating state of FIG. 5; [Figure 7] FIG. 7 is an explanatory diagram showing the operation state continued from FIG. 6. [Figure 8] FIG. 8 is an explanatory diagram showing a continued operating state from FIG. 7. [Figure 9] FIG. 13 is an explanatory diagram showing a modified example in which a placement core is placed in a fixed mold. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] An embodiment of an injection molding machine according to the present invention will be described with reference to the drawings. In the following description, the arrows in each drawing indicate F, B, R, L, U, and D, respectively.

[0023] As shown in FIG. 1, the injection molding machine 10 includes an injection unit 20, a mold clamping unit 30, and a mold 50.

[0024] In the injection device 20, a screw 22 is disposed in a cylindrical heating barrel 21, and the screw 22 is rotated by a hydraulic motor 23. A heater 24 for melting the synthetic resin W is disposed on the outer circumferential surface of the heating barrel 21. A hopper 25 for storing the synthetic resin W and supplying it into the heating barrel 21 is disposed at the front end of the heating barrel 21.

[0025] In the injection device 20, molten resin W1, which is heated by a heater 24 and converted from synthetic resin W into a molten state, is transported by a screw 22 and can be extruded from a nozzle 26 arranged at the rear end of a heating barrel 21.

[0026] The mold clamping device 30 includes a fixed platen 31 fixed on the bed 11, an end housing 32 arranged behind the fixed platen 31, multiple divers 33 arranged between the fixed platen 31 and the end housing 32, a movable platen 34 arranged between the fixed platen 31 and the end housing 32 and formed so that the divers 33 can be inserted through it, a toggle mechanism 36 arranged between the end housing 32 and the movable platen 34 and having a crosshead 35, a servo motor 37 as a drive device for driving the toggle mechanism 36, and a belt 39 connecting the servo motor 37 and the toggle mechanism 36 via a pulley 38.

[0027] An ejector 40 is provided on the movable platen 34, and an ejector rod 40a can be inserted through an insertion hole 34a formed to penetrate the movable platen 34 in the front-rear direction. An ejector pin 42 is attached to the front end of the ejector rod 40a via a plate-shaped plate 41, so that the completed molded product F can be pushed forward.

[0028] In the mold clamping device 30, a movable platen 34 can be moved in the front-rear direction by driving a servo motor 37.

[0029] As shown in FIGS. 3 to 8, the die 50 has a fixed die 51, a movable die 52, and a placement core 60.

[0030] The fixed die 51 is formed in a rectangular parallelepiped shape and is attached to the fixed platen 31. A receiving port 31a formed in a shape corresponding to the nozzle 26 is disposed in a position facing the nozzle 26 of the fixed platen 31. The fixed die 51 is formed with a sprue passage 51c that runs from the front end surface 51a to the rear end surface 51b and communicates with the receiving port 31a.

[0031] The movable mold 52 is formed in a rectangular parallelepiped shape and is attached to the movable platen 34 .

[0032] The movable mold 52 is composed of a front block 53 and a rear block 54.

[0033] The front block 53 is provided with: a bottomed hole portion 53c formed as a bottomed hole extending from the front end face 53a to the rear end face 53b of the front block 53; an ejector passage forming hole portion 53d which is narrower than the bottomed hole portion 53c and formed as a bottomed hole extending from the rear end face 53b to the front end face 53a of the front block 53; and a communicating hole portion 53e which is narrower than the bottomed hole portion 53c and wider than the ejector passage forming hole portion 53d, connecting the bottomed hole portion 53c and the ejector passage forming hole portion 53d.

[0034] A second air passage 53f is disposed in the front block 53. The second air passage 53f extends rearward in parallel with the ejector passage forming hole 53d from the bottomed hole 53c and then extends downward. A negative pressure measuring unit 70, which will be described later, is connected to the second air passage 53f.

[0035] The rear block 54 is provided with a plate placement portion 54c formed as a through hole extending from the front end surface 54a to the rear end surface 54b of the rear block 54.

[0036] The stationary core 60 is formed to be movable in the front-rear direction within the communication hole portion 53e. The stationary core 60 is provided with a molding recess 60c formed as a recess extending from the outer circumferential surface toward the axis.

[0037] In this embodiment, the space surrounded by the rear end surface 51b of the fixed die 51, the bottomed hole portion 53c, the front end surface 60a and molding recess 60c of the placement core 60, and the portion of the communicating hole portion 53e facing the molding recess 60c serves as the product molding portion 55. In other words, the communicating hole portion 53e forms a part of the product molding portion 55, and the portion not forming the product molding portion 55 functions as a recess in the claims.

[0038] The ejector passage forming hole 53d and the plate arrangement portion 54c form a first air passage 52a in the claims, and the plate 41 and the ejector pin 42 that form the ejector 40 are arranged in the first air passage 52a. There are gaps between the ejector rod 40a and the insertion hole 34a, and between the ejector pin 42 and the ejector passage forming hole 53d, allowing air to flow.

[0039] In this embodiment, the fixed mold 51, the movable mold 52, the placement core 60, and the negative pressure measurement unit 70 constitute a mold unit.

[0040] As shown in FIG. 2, the negative pressure measuring unit 70 includes a vacuum generator 71 as negative pressure means for creating a negative pressure state in the second air passage 53f, a pressure switch 72 as detection means for detecting the air pressure in the second air passage 53f, and a filter 73, and is connected to the second air passage 53f.

[0041] The second air passage 53f is connected to a detection means for detecting the air pressure in the second air passage 53f and a negative pressure means for making the second air passage 53f a negative pressure state, in that order, via a filter 73. The vacuum generator 71 is connected to an air compressor 75, and generates negative pressure by the force of air supplied from the air compressor 75. The arrows in Fig. 2 indicate the flow of air.

[0042] In this embodiment, the fixed mold 51, the movable mold 52, the placement core 60, and the negative pressure measurement unit 70 constitute a mold unit.

[0043] In the injection molding machine 10, the injection device 20, the mold clamping device 30, the negative pressure measuring unit 70, etc. are connected to a control means 80 including a communication interface, a control circuit, and a calculation processing circuit.

[0044] 2, the pressure switch 72 of the negative pressure measuring unit 70 and the mold 50 (movable mold 52) are connected to a control means 80. The vacuum generator 71 and the air compressor 75 operate independently of the control of the control means 80.

[0045] The vacuum generator 71, pressure switch 72 and air compressor 75 are set to operate at all times during the molding operation.

[0046] When the pressure switch 72 detects an air pressure within a predetermined range close to a vacuum, it outputs a signal to the control means 80 to enable the movable mold 52 to operate.

[0047] The manner in which the injection molding machine 10 is used will now be described.

[0048] The injection unit 20 of the injection molding machine 10 moves toward the mold clamping unit 30 and presses the rear end of the nozzle 26 against the receiving port 31a.

[0049] At this time, in the mold clamping device 30, the fixed mold 51 and the movable mold 52 are in close proximity to each other, as shown in Fig. 3. In addition, with the placed core 60 blocking the first air passage 52a and the second air passage 53f, the pressure switch 72 detects that the pressure is in a predetermined range close to a vacuum, so the movable mold 52 is in an operable state.

[0050] When a predetermined injection volume of molten resin W1 is injected from nozzle 26, molten resin W1 passes through sprue flow path 51c and is injected into product molding portion 55, as shown in FIG.

[0051] When a predetermined injection volume of molten resin W1 has been injected, the injection device 20 moves forward to prepare for the next injection operation.

[0052] When the molding of the molded product F is completed, as shown in FIG. 4, the movable mold 52 is moved away from the fixed mold 51 by driving the servo motor 37, and then, as shown in FIG. 5, the ejector 40 is driven to move the ejector pin 42 forward, thereby pushing the rear end surface 60b of the placed core 60, and the molded product F integrated with the placed core 60 is ejected.

[0053] After the worker separates the placed core 60 from the molded product F as shown in FIG. 6, the worker returns the placed core 60 to the communicating hole portion 53e as a recess as shown in FIG.

[0054] 5 to 7, the vacuum generator 71 and the pressure switch 72 are in an activated state, but there is a gap between the ejector pin 42 and the ejector passage forming hole 53d, and the placement core 60 does not block the first air passage 52a and the second air passage 53f, allowing air to flow in. Therefore, the pressure switch 72 does not detect that the pressure is in a predetermined range close to a vacuum, and the movable mold 52 does not operate.

[0055] 8, when the placed core 60 blocks the first air passage 52a and the second air passage 53f, the pressure switch 72 detects a change in air pressure caused by the vacuum generator 71, in other words, that the pressure is in a predetermined range close to a vacuum, and outputs a signal to the control means 80 to enable the movable die 52 to operate. This enables the movable die 52 to operate.

[0056] When the above invention is viewed as a mold unit, it is a mold unit used in an injection molding machine, which molds a molded product F by injecting molten resin W1 into a product molding section 55 formed by a fixed mold 51, a movable mold 52 that moves toward and away from the fixed mold 51, and a placement core 60 placed in the movable mold 52, The die unit includes a fixed die 51, a movable die 52, and a core holder 60. The movable die 52 in which the placement core 60 is disposed has: A recess (communication hole portion 53e) that opens to face the product molding portion 55 is provided, and a first air passage 52a (ejector passage forming hole portion 53d and plate arrangement portion 54c) through which air can flow and a second air passage 53f through which air can flow are provided at a position different from the first air passage 52a so as to communicate with the recess, The stationary core 60 is formed to be movable within the recess (the communication hole portion 53e) and is capable of simultaneously closing the first air passage 52a and the second air passage 53f. The second air passage 53f is connected in this order to a detection means (pressure switch 72) for detecting the air pressure in the second air passage 53f, and a negative pressure means (vacuum generator 71) for making the second air passage 53f in a negative pressure state. In the assembled state, the detection means is connected to a control means 80 that controls the operation of the injection molding machine 10. When the molding of the molded product F is completed and the movable mold 52 is separated from the fixed mold 51, the placed core 60 is positioned in the recess to close the first air passage 52a and the second air passage 53f, and when the detection means detects that the air pressure is at a predetermined level, a signal to enable the movable mold 52 to operate is output to the control means 80.

[0057] According to this, the first air passage 52a and the second air passage 53f are closed by the placed core 60, and the detection means detects that a predetermined air pressure is reached, so that the placed core 60 can be reliably returned to the movable side mold 52 with a simple configuration, and then molding work can be performed, resulting in a mold unit that does not damage the mold 50.

[0058] Further, an ejector 40 capable of sending out the placement core 60 to the product molding section 55 side can be disposed in the first air passage 52a.

[0059] According to this, the first air passage 52a also functions as a passage in which the ejector 40 is disposed, which leads to a simple configuration.

[0060] In addition, when the present invention is viewed as an injection molding machine, it is an injection molding machine that molds a molded product F by injecting molten resin W1 into a product molding section 55 formed by a fixed mold 51, a movable mold 52 that moves toward and away from the fixed mold 51, and a placement core 60 placed in the movable mold 52, A recess (communication hole portion 53e) that opens to face the product molding portion 55 is provided in the movable mold 52 in which the placement core 60 is arranged, and a first air passage 52a through which air can flow and a second air passage 53f through which air can flow are provided at a position different from the first air passage 52a so as to communicate with the recess, The stationary core 60 is formed to be movable within the recess (the communication hole portion 53e) and is capable of simultaneously closing the first air passage 52a and the second air passage 53f. The second air passage 53f is connected in this order to a detection means (pressure switch 72) for detecting the air pressure in the second air passage 53f, and a negative pressure means (vacuum generator 71) for making the second air passage 53f in a negative pressure state. A control means 80 is provided which controls the operation of the injection molding machine 10 and is connected to the detection means; When the molding of the molded product F is completed and the movable mold 52 is separated from the fixed mold 51, the control means 80 closes the first air passage 52a and the second air passage 53f by positioning the placement core 60 in the recess, and the detection means detects that the air pressure is at a predetermined level, and then makes the movable mold 52 operable.

[0061] This makes it possible to provide an injection molding machine that exhibits the effects of the above-mentioned mold unit.

[0062] Further, an ejector 40 capable of sending out the placement core 60 to the product molding section 55 side is disposed in the first air passage 52a.

[0063] This makes it possible to provide an injection molding machine that exhibits the effects of the above-mentioned mold unit.

[0064] Moreover, a negative pressure means (vacuum generator 71) and a detection means (pressure switch 72) are provided on the outside of the movable mold 52 in which the placement core 60 is disposed.

[0065] According to this, the negative pressure means and the detection means can be removed from the movable mold 52 for maintenance, which makes it possible to facilitate maintenance management.

[0066] In addition, a filter 73 is disposed between the second air passage 53f and the detection means (pressure switch 72).

[0067] According to this, the filter 73 can prevent problems caused by dirt on the negative pressure means and the detection means.

[0068] The present invention is not limited to the above configuration. In other words, various design changes and the like are possible without departing from the gist of the present invention. The same configurations as those in the first embodiment are given the same numbers, and the description thereof will be omitted in whole or in part.

[0069] For example, a modified example in which a placement core is disposed in the fixed die will be described with reference to FIG.

[0070] The fixed side mold 151 is provided with a bottomed hole portion 151c formed as a bottomed hole extending from the rear end face 151b of the fixed side mold 151 to the front end face 151a of the fixed side mold 151, and a communicating hole portion 151e which is narrower than the bottomed hole portion 151c and is formed as a bottomed hole extending from the bottom of the bottomed hole portion 151c to the front end face 151a of the fixed side mold 151.

[0071] The fixed mold 151 is provided with a first air passage 151d that is formed to extend forward from the bottomed hole portion 151c and then extend downward.

[0072] Further, a second air passage 151f formed to extend forward from the bottomed hole portion 151c and then extend upward is disposed in the fixed-side mold 151. The negative pressure measuring unit 70 is connected to the second air passage 151f.

[0073] With this configuration, it is possible to provide a mold unit and injection molding machine with a simple configuration in which the placed core 60 can be reliably returned to the fixed side mold 151 before molding work is performed, without damaging the mold 50.

[0074] Although a toggle type mold clamping device is used as the mold clamping device 30, a direct pressure type mold clamping device can also be used.

[0075] Furthermore, the injection device 20 is not limited to the above-described configuration, and any existing injection device can be used as long as it can inject the molten resin W1 into the product molding section 55.

[0076] Furthermore, the shape of the product molding portion 55 can be changed as appropriate.

[0077] It is also possible to reverse the concave and convex shapes of the fixed mold 51 and the movable mold 52 .

[0078] In addition, the placement core 60 can also be disposed in the fixed mold 51 and the movable mold 52. [Explanation of symbols]

[0079] 10 injection molding machine 40 Ejector 51 Fixed side mold 52 Movable side mold 52a First air passage 53d Ejector passage forming hole 53e Communication hole 53f Second air passage 54c Plate placement section 55 Product molding department 60 Placed core 71 Vacuum Generator 72 Pressure switch 80 Control Means 151 Fixed side mold 151d First air passage 151e Communication hole 151f Second air passage F Molded product W1 Molten Resin

Claims

1. A mold unit used in an injection molding machine, which molds a molded product by injecting molten resin into a product molding section formed by a fixed mold, a movable mold that moves toward and away from the fixed mold, and a core placed in the fixed mold and / or the movable mold, The die unit includes the fixed die, the movable die, and the placement core, The fixed-side mold and / or the movable-side mold in which the placement core is disposed include: a recessed portion is provided so as to open toward the product molding portion, and a first air passage through which air can flow and a second air passage through which air can flow are provided at a position different from the first air passage so as to communicate with the recessed portion, the placing core is formed to be movable within the recess and is capable of simultaneously closing the first air passage and the second air passage, the second air passage is connected in this order to a detection means for detecting an air pressure in the second air passage and a negative pressure means for putting the second air passage into a negative pressure state; In an assembled state, the detection means is connected to a control means for controlling the operation of the injection molding machine, When molding of the molded product is completed and the movable mold is separated from the fixed mold, the placement core is positioned in the recess to close the first air passage and the second air passage, and when the detection means detects a predetermined air pressure, a signal to enable the movable mold to operate is output to the control means.

2. 2. The mold unit according to claim 1, wherein an ejector capable of sending the placed core toward the product molding portion can be disposed in the first air passage.

3. An injection molding machine that molds a molded product by injecting molten resin into a product molding section formed by a fixed-side mold, a movable-side mold that moves toward and away from the fixed-side mold, and a core placed in the fixed-side mold and / or the movable-side mold, a recessed portion opening toward the product molding portion is provided in the fixed mold and / or the movable mold in which the placement core is disposed, and a first air passage through which air can flow and a second air passage through which air can flow are provided at a position different from the first air passage so as to communicate with the recessed portion, the placing core is formed to be movable within the recess and is capable of simultaneously closing the first air passage and the second air passage, the second air passage is connected in this order to a detection means for detecting an air pressure in the second air passage and a negative pressure means for putting the second air passage into a negative pressure state; a control means for controlling the operation of the injection molding machine and connected to the detection means; the control means, when molding of the molded product is completed and the movable-side mold is separated from the fixed-side mold, the placement core is positioned in the recess to close the first air passage and the second air passage, and when the detection means detects a predetermined air pressure, makes the movable-side mold operable.

4. 4. The injection molding machine according to claim 3, wherein an ejector capable of sending out the placed core toward the product molding section is disposed in the first air passage.

5. 5. The injection molding machine according to claim 3, wherein the negative pressure means and the detection means are disposed outside the fixed mold and / or the movable mold in which the placed core is disposed.

6. 5. The injection molding machine according to claim 3, further comprising a filter disposed between said second air passage and said detection means.

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