Nozzle adapter, injection device, and injection molding machine

Abstract

To prevent or suppress temperature fall of a molten resin during passage through a nozzle adapter.SOLUTION: A nozzle adapter 50 has a resin flow path P1 communicating with a heating cylinder 30 and an injection nozzle 40, and a heater 70 provided in the periphery of the resin flow path P1.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an injection molding machine for molding resin members.

Background Art

[0002] An injection molding machine for molding a resin member (resin molded product) having a desired shape is known. A general injection molding machine is composed of an injection device and a mold clamping device. The injection device melts a resin material and supplies the melted resin material (molten resin) to the mold clamping device. More specifically, the injection device injects (ejects) the molten resin into the cavity of the mold.

[0003] The injection device includes a heating cylinder for producing molten resin, an injection nozzle for injecting the molten resin, and a nozzle adapter for attaching the injection nozzle to the heating cylinder. The molten resin produced by the heating cylinder flows into the injection nozzle through the nozzle adapter and is ejected from the tip of the injection nozzle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] If the temperature of the molten resin drops while passing through the nozzle adapter, there is a risk that voids will occur inside the resin molded product.

[0006] Other problems and novel features will become apparent from the description of this specification and the accompanying drawings.

Means for Solving the Problems

[0007] A nozzle adapter according to an embodiment includes a connection end portion provided at one end side in the axial direction, a flange portion provided at the other end side in the axial direction, an intermediate portion provided between the connection end portion and the flange portion, and a resin flow path that penetrates at least the intermediate portion and communicates with the heating cylinder and the injection nozzle. A groove extending in the circumferential direction is provided around the intermediate portion, and a heater is accommodated in the groove.

Advantages of the Invention

[0008] According to one embodiment, a temperature drop of the molten resin during passage through the nozzle adapter is prevented or suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] Hereinafter, one embodiment will be described in detail with reference to the drawings. In all the drawings for explaining the embodiment, members, devices, etc. having the same or substantially the same functions are denoted by the same reference numerals, and repeated explanations thereof are omitted.

[0011] <Injection Molding Machine> FIG. 1 is a schematic diagram showing an injection molding machine according to the present embodiment. The illustrated injection molding machine 1 is composed of a mold clamping device 2 and an injection device 3. Molds 11 and 12 are attached to the mold clamping device 2. The mold clamping device 2 opens and closes the attached molds 11 and 12. The injection device 3 heats and melts the resin material. The injection device 3 injects the melted resin material (molten resin) into the molds 11 and 12 attached to the mold clamping device 2. More specifically, the injection device 3 injects the molten resin into the cavity of the molds 11 and 12.

[0012] <Mold clamping device> The mold clamping device 2 includes a fixed platen 14, a mold clamping housing 15, and a movable platen 16 provided on a common bed 13. The fixed platen 14 is fixed to the bed 13. On the other hand, the mold clamping housing 15 and the movable platen 16 are slidable on the bed 13.

[0013] The fixed platen 14 and the mold clamping housing 15 are connected by a plurality of tie bars 17. More specifically, the fixed platen 14 and the mold clamping housing 15 are connected by four tie bars 17. The movable platen 16 is slidable in the opposing direction between the fixed platen 14 and the mold clamping housing 15.

[0014] A mold clamping mechanism 18 is provided between the mold clamping housing 15 and the movable platen 16. More specifically, a link-type mold clamping mechanism 18 is provided between the mold clamping housing 15 and the movable platen 16. Viewed another way, a toggle mechanism is provided between the mold clamping housing 15 and the movable platen 16.

[0015] The mold clamping mechanism 18 moves the mold 11 attached to the movable platen 16 forward and backward with respect to the mold 12 attached to the fixed platen 14. When the mold 11 contacts the mold 12, the molds 11 and 12 are closed. On the other hand, when the mold 11 separates from the mold 12, the molds 11 and 12 are opened. The mold clamping mechanism 18 can press the mold 11 against the mold 12 so that the molds 11 and 12 do not open while they are closed. Incidentally, the mold clamping mechanism 18 can be replaced with a direct pressure type mold clamping mechanism (mold clamping cylinder).

[0016] <Injection Device> The injection device 3 is provided on the base 20 adjacent to the bed 13. The injection device 3 is composed of a heating cylinder, an injection nozzle, a shut-off nozzle, etc. The injection device 3 is driven by the nozzle touch device 21 in the direction (forward) approaching the mold clamping device 2 and also in the direction (backward) separating from the mold clamping device 2. That is, the injection device 3 moves forward and backward (recedes) with respect to the mold clamping device 2. When the injection device 3 advances to a predetermined position, the tip of the injection nozzle 40 contacts the sprue bush of the mold 12.

[0017] A hopper 31 is provided on the rear end side of the heating cylinder 30. The hopper 31 is a supply port for supplying the resin material to the heating cylinder 30. The resin material is put into the hopper 31 and fed into the heating cylinder 30 through the hopper 31.

[0018] A screw 32 is provided inside the heating cylinder 30. The screw 32 is driven inside the heating cylinder 30 by a drive mechanism covered by a cover 33. Viewed from another perspective, the screw 32 makes a rotational motion inside the heating cylinder 30. Also, the screw 32 makes a linear motion inside the heating cylinder 30. Note that the direction of the linear motion of the screw 32 is the same as the moving direction of the injection device 3 with respect to the mold clamping device 2. That is, the screw 32 is linearly driven inside the heating cylinder 30 in the direction (forward) approaching the mold clamping device 2 and the direction (backward) separating from the mold clamping device 2.

[0019] The heating cylinder 30 heats and melts the supplied resin material. A heater for heating the heating cylinder 30 is provided around the heating cylinder 30. For example, one or more band heaters are wound around the heating cylinder 30. The resin material supplied to the heating cylinder 30 is heated and melted by the heat emitted from the heater and the shear heat generated by the rotation of the screw 32.

[0020] <Method for Manufacturing a Resin Molded Product> Next, an example of the procedure (process) for manufacturing a resin molded product using the injection molding machine 1 shown in FIG. 1 will be described. First, the molds 11 and 12 attached to the mold clamping device 2 are opened, and the injection device 3 is retracted.

[0021] Then, a resin material is charged into the hopper 31 of the injection device 3. For example, a resin material processed into beads or pellets is charged into the hopper 31. However, the resin material may be charged into the hopper 31 in advance before retracting the injection device 3.

[0022] The resin material charged into the hopper 31 is supplied to the heating cylinder 30. The resin material supplied to the heating cylinder 30 is heated and melted. The melted resin material (molten resin) is sent to the tip side of the heating cylinder 30 by the rotation of the screw 32. In other words, the cavity between the screw 32 and the injection nozzle 40 is filled with the molten resin.

[0023] Thereafter, the injection device 3 is advanced, and the tip of the injection nozzle 40 is brought into contact with the sprue bush of the mold 12 (the molds 11 and 12 are pre-closed). Next, the screw 32 is moved forward in the heating cylinder 30. At this time, the screw 32 is not rotated. Then, the molten resin is injected (ejected) into the cavities of the molds 11 and 12 from the tip (ejection port) of the injection nozzle 40.

[0024] The screw 32 continues to apply pressure (holding pressure) to the molten resin even after injecting the molten resin into the cavity. The molds 11 and 12 are cooled while maintaining the state where pressure is applied to the molten resin in the cavity.

[0025] While the molds 11 and 12 are being cooled, the screw 32 is rotated again in preparation for the next injection. Specifically, the screw 32 is rotated to send the molten resin to the tip side of the heating cylinder 30. That is, the molten resin to be injected next is filled between the screw 32 and the injection nozzle 40. As a result, the screw 32 retreats due to the reaction force. This process of retreating the screw 32 while sending the molten resin forward is called "metering".

[0026] After the molds 11 and 12 are cooled to a temperature below the temperature at which the molten resin in the cavity solidifies, the molds 11 and 12 are opened to take out the resin molded product.

[0027] By repeating the above process, resin molded products of the same shape are continuously manufactured. That is, resin molded products of a desired shape are mass-produced.

[0028] <Nozzle adapter> Next, the connection structure between the heating cylinder 30 and the injection nozzle 40 will be described. FIG. 2 is a partial cross-sectional view showing the connection portion between the heating cylinder 30 and the injection nozzle 40. A nozzle adapter 50 is interposed between the heating cylinder 30 and the injection nozzle 40. The injection nozzle 40 is attached to the tip of the heating cylinder 30 via the nozzle adapter 50.

[0029] Inside the nozzle adapter 50, a resin flow path P1 that penetrates the nozzle adapter 50 in the axial direction and communicates with the heating cylinder 30 and the injection nozzle 40 is provided. Inside the injection nozzle 40, a resin flow path P2 that penetrates the injection nozzle 40 in the axial direction is provided. One end of the resin flow path P2 in the injection nozzle 40 communicates with the resin flow path P1 in the nozzle adapter 50, and the other end of the resin flow path P2 in the injection nozzle 40 communicates with the injection port 41 of the injection nozzle 40. As a result, a series of resin flow paths P from the heating cylinder 30 to the injection port 41 of the injection nozzle 40 are formed. In the following description, the resin flow path P1 in the nozzle adapter 50 may be referred to as the "adapter flow path P1", and the resin flow path P2 in the injection nozzle 40 may be referred to as the "nozzle flow path P2" for distinction. Also, the nozzle adapter 50 may be abbreviated as the "adapter 50".

[0030] FIG. 3 is a cross-sectional view showing the adapter 50. The adapter 50 has an adapter body 51 and a flange portion 52, and the adapter body 51 includes a connection end portion 53 and an intermediate portion 54. The connection end portion 53 is provided at one axial end side (rear end side) of the adapter 50, and the flange portion 52 is provided at the other axial end side (front end side) of the adapter 50. Further, the intermediate portion 54 is provided between the connection end portion 53 and the flange portion 52. That is, the connection end portion 53, the intermediate portion 54, and the flange portion 52 are arranged in this order along the axial direction. More specifically, the connection end portion 53, the intermediate portion 54, and the flange portion 52 are arranged in this order from the rear end side to the front end side of the adapter 50. Viewed from another perspective, the connection end portion 53, the intermediate portion 54, and the flange portion 52 are arranged in this order from the upstream side to the downstream side of the resin flow path P.

[0031] However, the adapter 50 is not a single member but is composed of two members integrally formed in a separable manner. That is, the adapter 50 is of a split type. Specifically, the adapter 50 is composed of a metal member 51A forming the adapter body 51 and a metal member 52B forming the flange portion 52. Incidentally, the metal member 51A forming the adapter body 51 is also a metal member forming the connection end portion 53 and the intermediate portion 54.

[0032] One metal member 51A forming the adapter body 51 has a cylindrical shape as a whole. The other metal member 52B forming the flange portion 52 has an annular shape as a whole. These two metal members 51A and 52B are integrated by screw connection.

[0033] <Adapter body> The adapter body 51 has a stepped shape in which the outer diameter changes stepwise along the axial direction. The connection end portion 53 is formed by a part of the adapter body 51 having the largest outer diameter. On the outer peripheral surface of the connection end portion 53, a screw that can be coupled to the screw formed on the inner peripheral surface of the heating cylinder 30 is formed.

[0034] The adapter 50 is fixed to the heating cylinder 30 by coupling the screw formed on the outer peripheral surface of the connection end portion 53 to the screw formed on the inner peripheral surface of the heating cylinder 30.

[0035] The intermediate portion 54 is formed by a part of the adapter body 51 having an outer diameter smaller than that of the portion forming the connection end portion 53.

[0036] The connecting portion 56 is formed by a part of the adapter body 51 having an outer diameter even smaller than that of the portion forming the intermediate portion 54. In other words, the connecting portion 56 is a convex portion provided on the tip surface of the adapter body 51. On the outer peripheral surface of the connecting portion 56, a screw that can be coupled to the screw formed on the inner peripheral surface of the flange portion 52 is formed.

[0037] The adapter flow path P1 penetrates the adapter body 51 in the axial direction. More specifically, the adapter flow path P1 penetrates the connection end portion 53, the intermediate portion 54, and the connecting portion 56. An insertion hole 55 that extends obliquely toward the adapter flow path P1 is provided in the intermediate portion 54.

[0038] <Flange portion> The outer diameter of the flange portion 52 is larger than the outer diameter of the connection end portion 53. Also, the inner diameter of the flange portion 52 is smaller than the outer diameter of the intermediate portion 54 and larger than the outer diameter of the connecting portion 56. On the inner peripheral surface of the flange portion 52, a screw that can be coupled to the screw formed on the outer peripheral surface of the connecting portion 56 is formed. By coupling the screw formed on the inner peripheral surface of the flange portion 52 to the screw formed on the outer peripheral surface of the connecting portion 56, the flange portion 52 is fixed to the adapter body 51. That is, the adapter body 51 and the flange portion 52 are integrated, and the adapter 50 is assembled.

[0039] The flange portion 52 is thicker than the height (projection length) of the connecting portion 56. Therefore, even when the adapter body 51 and the flange portion 52 are integrated as described above, the connecting portion 56 does not protrude from the flange portion 52.

[0040] <Groove portion> A groove 60 extending along the circumferential direction of the intermediate portion 54 is provided around the intermediate portion 54. The groove 60 is provided over the entire circumference of the intermediate portion 54. In other words, a recess is provided over the entire circumference on the outer peripheral surface of the adapter 50.

[0041] The groove 60 is formed by the connection end portion 53, the flange portion 52, and the intermediate portion 54. Specifically, one inner side surface 61 of the groove 60 is formed by the end surface 53a of the connection end portion 53 facing the flange portion 52. The other inner side surface 62 of the groove 60 is formed by the end surface 52b of the flange portion 52 facing the connection end portion 53. Further, the bottom surface 63 of the groove 60 is formed by the outer peripheral surface 54c of the intermediate portion 54.

[0042] In other words, the inner side surfaces 61 and 62 of the groove 60 are formed by the front surface 53a of the opposing connection end portion 53 and the back surface 52b of the flange portion 52. However, when the adapter body 51 and the flange portion 52 are integrated, a part of the back surface 52b of the flange portion 52 faces and is in close contact with the front surface 54a of the intermediate portion 54. That is, the inner side surface 62 of the groove 60 is formed by a part (annular region) of the back surface 52b of the flange portion 52 that protrudes radially outward from the front surface 54a of the intermediate portion 54.

[0043] As described above, an insertion hole 55 extending toward the adapter flow path P1 is provided in the intermediate portion 54 of the adapter body 51. This insertion hole 55 extends obliquely from the outer peripheral surface 54c of the intermediate portion 54 toward the adapter flow path P1. That is, the insertion hole 55 is drilled in the outer peripheral surface 54c (bottom surface 63 of the groove 60) of the intermediate portion 54. Note that the inclination angle of the insertion hole 55 with respect to the adapter flow path P1 can be changed as appropriate. However, the insertion hole 55 does not have to be inclined.

[0044] <Heater, heat insulating material> The adapter 50 has a heater 70 provided around the resin flow path P1. More specifically, the heater 70 is accommodated in a groove 60 provided around the intermediate portion 54. Further, around the heater 70, a heat insulating material 71 that covers the heater 70 is disposed. The total thickness of the heater 70 and the heat insulating material 71 is the same as or substantially the same as the depth of the groove 60. As a result, the outer peripheral surface of the heat insulating material 71 is flush with or substantially flush with the outer peripheral surface of the connection end portion 53.

[0045] FIG. 4 is an explanatory diagram showing the assembly procedure of the adapter 50. The heater 70 is a cylindrical micro heater having an inner diameter into which the intermediate portion 54 of the adapter body 51 can be inserted. The heat insulating material 71 is a cylindrical heat insulating plate having an inner diameter into which the heater 70 can be inserted. For the heat insulating material 71, for example, a rigid heat insulating plate in which a laminated glass fiber sheet is molded with a binder or resin can be used.

[0046] When assembling the adapter 50, the intermediate portion 54 of the adapter body 51 is inserted inside the heater 70. In other words, the heater 70 is put on the intermediate portion 54 of the adapter body 51. Then, the heat insulating material 71 is put on the heater 70. Next, the flange portion 52 is fixed to the adapter body 51. Then, a groove 60 shown in FIG. 3 is formed around the intermediate portion 54, and the heater 70 and the heat insulating material 71 are accommodated in the groove 60. Further, the outer peripheral surface 54c (bottom surface 63 of the groove 60) of the intermediate portion 54 is covered by the heater 70, and the heater 70 is covered by the heat insulating material 71.

[0047] When the heater 70 operates, the adapter 50 is heated, and the molten resin passing through the adapter flow path P1 is heated. Thus, a temperature drop of the molten resin passing through the adapter 50 is prevented or suppressed.

[0048] Furthermore, the heater 70 is not limited to a micro heater. For example, the heater 70 can be replaced with a band heater wound around the outer peripheral surface of the adapter 50, a nichrome wire, or the like. Also, the heater 70 can be provided inside the adapter 50. For example, the heater 70 can be replaced with a cast-in heater embedded in the adapter 50. The heat insulating material 71 is not limited to a rigid heat insulating plate. The heat insulating material 71 can also be omitted.

[0049] <Temperature sensor> Referring to FIG. 2 again, a temperature sensor 72 using a thermocouple is inserted into the insertion hole 55 provided in the intermediate portion 54. More specifically, one end side of the temperature sensor 72 including the temperature detection portion is inserted into the insertion hole 55, and the other end side of the temperature sensor 72 is drawn out of the adapter 50.

[0050] The insertion hole 55 reaches the vicinity of the adapter flow path P1. Therefore, the temperature sensor 72 can detect the temperature in the vicinity of the adapter flow path P1. The temperature in the vicinity of the adapter flow path P1 reflects the temperature of the molten resin flowing through the adapter flow path P1.

[0051] The voltage (signal) output from the temperature sensor 72 is input to a heater control unit (not shown). The heater control unit controls the heater 70 based on the input signal. More specifically, the heat generation amount of the heater 70 is controlled so that the temperature in the vicinity of the adapter flow path P1 is maintained within a predetermined temperature range. That is, the heater 70 is feedback-controlled based on the temperature measurement result of the temperature sensor 72.

[0052] When assembling the adapter 50 according to the procedure shown in FIG. 4, the temperature sensor 72 is inserted into the insertion hole 55 before covering the intermediate portion 54 with the heater 70.

[0053] <Pressing member> The injection nozzle 40 and the adapter 50 are fixed to each other by two pressing members 81 and 82. The pressing members 81 and 82 are substantially annular metal members that face each other with the flange portion 52 of the adapter 50 interposed therebetween.

[0054] The pressing member 81 is disposed around the middle portion 54 of the adapter body 51 and covers the groove 60. In other words, the groove 60 and the pressing member 81 form a housing space for the heater 70 and the heat insulating material 71. On the other hand, the pressing member 82 is disposed around the base end portion of the injection nozzle 40 and surrounds the base end portion.

[0055] A plurality of bolt holes 81a are provided at equal intervals along the circumferential direction in the pressing member 81. A plurality of through holes 82a are provided at equal intervals along the circumferential direction in the pressing member 82. The pressing member 81 is positioned by the positioning pin 83, and the pressing member 82 is positioned by the positioning pin 84. When the pressing members 81 and 82 are positioned by the positioning pins 83 and 84, the corresponding bolt holes 81a and through holes 82a communicate with each other.

[0056] The pressing members 81 and 82 are fixed to each other by bolts 85 that pass through the through holes 82a and are screwed into the bolt holes 81a. Therefore, when the bolts 85 are tightened, a force acts on the pressing members 81 and 82 to bring them closer to each other. Then, the pressing member 81 is pressed against the flange portion 52 of the adapter 50. At the same time, the pressing member 82 is pressed against the flange portion 42 of the injection nozzle 40, and the rear end face of the injection nozzle 40 is pressed against the front end face of the adapter body 51.

[0057] As a result, the injection nozzle 40 and the adapter 50 are fixed to each other. In other words, the injection nozzle 40 is fixed to the adapter 50 that is fixed to the heating cylinder 30. That is, the injection nozzle 40 is attached to the heating cylinder 30.

[0058] In addition, the rear end portion of the injection nozzle 40 (the portion protruding rearward from the flange portion 42) enters the inside of the flange portion 52. Therefore, the rear end face of the injection nozzle 40 is pressed against the front end face of the adapter body 51 inside the flange portion 52. In other words, the adapter flow path P1 and the nozzle flow path P2 are connected inside the flange portion 52.

[0059] <Shut-off nozzle> The shut-off nozzle 90 shown in Fig. 2 opens and closes the nozzle flow path P2. The shut-off nozzle 90 includes a needle valve 91 that is reciprocally driven by a drive mechanism (cylinder unit) (not shown). The tip of the needle valve 91 is inserted into a needle hole 43 provided in the injection nozzle 40.

[0060] The needle valve 91 is reciprocally driven between a first position where its tip enters the nozzle flow path P2 and a second position where its tip retracts from the nozzle flow path P2. When the needle valve 91 moves from the second position to the first position, the nozzle flow path P2 is closed by the tip of the needle valve 91. On the other hand, when the needle valve 91 moves from the first position to the second position, the nozzle flow path P2 that was closed by the tip of the needle valve 91 is opened.

[0061] By providing the shut-off nozzle 90, the injection of the molten resin from the injection nozzle 40 can be stopped quickly and surely. Such an advantage is particularly effective when the fluidity of the molten resin handled by the injection device 3 is high or when the molten resin has foamability. On the other hand, in order to provide the shut-off nozzle 90, it is necessary to secure a space for arranging the needle valve 91 between the heating cylinder 30 and the injection nozzle 40. More specifically, it is necessary to move the injection nozzle 40 away from the heating cylinder 30.

[0062] In the present embodiment, the total length of the adapter 50 is set to a length that secures a space necessary and sufficient for arranging the needle valve 91 between the heating cylinder 30 and the injection nozzle 40. However, when the adapter 50 becomes longer, the surface area of the adapter 50 increases and the heat dissipation amount increases. Then, the temperature of the molten resin decreases while passing through the adapter 50, and voids are likely to occur.

[0063] Therefore, in the present embodiment, a heater 70 is provided on the adapter 50 to prevent or suppress a temperature drop of the molten resin. Further, in the present embodiment where the heater 70 can be controlled based on the temperature measurement result of the temperature sensor 72, the temperature of the molten resin passing through the adapter 50 can also be positively adjusted.

[0064] The material of the resin molded product molded by the injection molding machine 1 of the present embodiment is not particularly limited. As an example of the material of the resin molded product, a thermoplastic resin can be mentioned. More specifically, polypropylene (PP), polyphenylene sulfide (PPS), acrylic resin, polyester resin, urethane resin, etc. can be mentioned as an example of the material of the resin molded product.

[0065] On the other hand, when the temperature of the thermoplastic resin melted by shear heating decreases, gas volatile components are likely to be generated. That is, voids are likely to occur in the resin molded product made of the thermoplastic resin melted by shear heating. In particular, voids are likely to occur in resin molded products made of polypropylene or polyphenylene sulfide with low viscosity.

[0066] In addition, voids generated in resin molded products made of transparent resins such as acrylic resin, polyester resin, and urethane resin, or resins with high transparency are easy to detect and are likely to cause a decrease in the quality of the resin molded product.

[0067] Until now, when voids occurred in the resin molded product, countermeasures such as eliminating sudden wall thickness variations in the mold were taken. However, even if the mold was modified at a cost, the generation of voids could not be sufficiently prevented.

[0068] On the other hand, in the injection molding machine 1 of the present embodiment in which the temperature of the adapter 50 arranged in front of the injection nozzle 40 is adjustable, the generation of gas volatile components that cause voids can be suppressed in the injection nozzle 40. Therefore, it is possible to sufficiently prevent or suppress the generation of voids while saving the cost required for mold modification.

[0069] Note that maintaining and adjusting the temperature of the molten resin is also required for an injection device not equipped with a shut-off nozzle. If the injection nozzle of the present embodiment is attached to the heating cylinder of another injection device not equipped with a shut-off nozzle, it is possible to maintain and adjust the temperature of the molten resin even with that injection device.

[0070] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, it goes without saying that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof.

[0071] As shown in FIG. 5, a heater 86 that covers the pressing members 81 and 82 may be provided around the pressing members 81 and 82. The illustrated heater 86 is a band heater wound around the outer peripheral surface of the pressing members 81 and 82 and can be switched between an operating state and a non-operating state as required. By providing the heater 86, a temperature drop of the molten resin is further prevented or suppressed. However, the heater 86 is not limited to a band heater. For example, the heater 86 can also be replaced with a micro heater similar to the heater 70 or other heaters.

[0072] It is not essential to perform feedback control on the heater 70. For example, the heater 70 may be alternatively switched between an operating state and a non-operating state based on the temperature measurement result of the temperature sensor 72. Also, the heater 70 may be continuously operated in a constant heat generation state. In this case, the temperature sensor 72 may be omitted.

[0073] The adapter 50 may be a single member. That is, the adapter 50 may be formed of one metal member including the adapter body 51 and the flange portion 52. However, the split-type adapter 50 has the advantage that the heater 70 and the heat insulating material 71 can be easily assembled. Also, the adapter 50 is not limited to having a flange portion 52.

[0074] The temperature sensor 72 is not limited to one. For example, a plurality of insertion holes 55 may be provided in the intermediate portion 54, and the temperature sensor 72 may be inserted into each insertion hole 55. When a plurality of temperature sensors 72 are arranged, those temperature sensors 72 may be arranged along the longitudinal direction of the adapter flow path P1 or along the circumferential direction of the adapter flow path P1. Note that the temperature sensor 72 is not limited to a temperature sensor using a thermocouple.

Explanation of Reference Numerals

[0075] 1 Injection molding machine 2 Mold clamping device 3 Injection device 11, 12 Mold 13 Bed 14 Fixed platen 15 Mold clamping housing 16 Movable platen 17 Tie bar 18 Mold clamping mechanism 20 Base 21 Nozzle touch device 30 Heating cylinder 31 Hopper 32 Screw 33 Cover 40 Injection nozzle 41 Injection port 42 Flange portion 43 Needle hole 50 Nozzle adapter (adapter) 51A, 51B Metal member 52 Flange portion 52b End face (back face) 53 Connection end portion 53a End face (front face) 54 Intermediate portion 54c Outer peripheral surface 55 Insertion hole 56 Connecting portion 60 Groove 61, 62 Inner surface 63 Bottom surface 70, 86 Heater 71 Heat insulating material 72 Temperature sensor 81, 82 Pressing member 81a Bolt hole 82a Through hole 83, 84 Positioning pin 85 Bolt 90 Shut-off nozzle 91 Needle valve P Resin flow path P1 Resin flow path (adapter flow path) P2 Resin flow path (nozzle flow path)

Claims

1. A nozzle adapter for attaching an injection nozzle to a heating cylinder of an injection device, comprising: a connection end provided at one end side in the axial direction; a flange portion provided at the other end side in the axial direction; an intermediate portion provided between the connection end and the flange portion; a resin flow path that penetrates at least the intermediate portion and communicates with the heating cylinder and the injection nozzle; a heater provided around the resin flow path; and the heater is provided around or inside the intermediate portion, the nozzle adapter.

2. The nozzle adapter according to claim 1, having an insertion hole into which a temperature sensor is inserted.

3. The nozzle adapter according to claim 1 or 2, having a heat insulating material covering the heater.

4. A groove along the circumferential direction is provided around the intermediate portion, The nozzle adapter according to any one of claims 1 to 3, wherein the heater is accommodated in the groove.

5. One inner side surface of the groove is formed by an end surface of the connection end facing the flange portion, The other inner side surface of the groove is formed by an end surface of the flange portion facing the connection end, The nozzle adapter according to claim 4, wherein a bottom surface of the groove is formed by an outer peripheral surface of the intermediate portion.

6. Composed of two metal members integrated by screw connection, The connection end and the intermediate portion are formed by one of the two metal members, and the flange portion is formed by the other of the two metal members. The nozzle adapter according to any one of claims 1 to 5.

7. The heater has a cylindrical shape into which the intermediate portion can be inserted. The nozzle adapter according to claim 6.

8. An injection device for injecting molten resin, comprising: a heating cylinder for heating a resin material to produce molten resin; an injection nozzle for injecting the molten resin produced by the heating cylinder; a nozzle adapter interposed between the heating cylinder and the injection nozzle; and a pressing member for fixing the injection nozzle and the nozzle adapter to each other. The nozzle adapter is a resin flow path that communicates with the heating cylinder and the injection nozzle; a heater provided around the resin flow path. The injection device.

9. The injection device according to claim 8, wherein the nozzle adapter has at least one of an insertion hole into which a temperature sensor is inserted and a heat insulating material covering the heater.

10. The nozzle adapter is a connection end provided at one end side in the axial direction; a flange portion provided on the other end side in the axial direction, and an intermediate portion provided between the connection end portion and the flange portion, wherein the resin flow path penetrates at least the intermediate portion, and the heater is provided around or inside the intermediate portion. The injection device according to claim 8 or 9.

11. A groove extending along the circumferential direction is provided around the intermediate portion, and the heater is accommodated in the groove. The injection device according to claim 10.

12. The pressing member includes two pressing members facing each other with the flange portion of the nozzle adapter therebetween, and at least one of the two pressing members covers at least a part of the intermediate portion. The injection device according to claim 10 or 11.

13. A heater covering the pressing member is provided around the pressing member. The injection device according to claim 12.

14. The injection device according to any one of claims 8 to 13, having a shut-off nozzle for opening and closing a resin flow path provided inside the injection nozzle.

15. An injection molding machine comprising a mold clamping device to which a mold is attached and an injection device for injecting molten resin into the mold, wherein the injection device includes a heating cylinder for heating a resin material to produce molten resin, an injection nozzle for injecting the molten resin produced by the heating cylinder, a nozzle adapter interposed between the heating cylinder and the injection nozzle, and a pressing member for fixing the injection nozzle and the nozzle adapter to each other, wherein the nozzle adapter includes a resin flow path communicating with the heating cylinder and the injection nozzle, and a heater provided around the resin flow path. An injection molding machine.

16. The injection molding machine according to claim 15, having a shut-off nozzle for opening and closing a resin flow path provided inside the injection nozzle.

17. The resin material is any one of polypropylene, polyphenylene sulfide, acrylic resin, polyester resin, or urethane resin. The injection molding machine according to claim 15 or 16.

Images