Nozzle heater device and injection molding machine

Abstract

This suppresses axial misalignment of the nozzle heater of an injection molding machine. [Solution] The nozzle heater device 1 includes a heater 10 arranged to surround a nozzle 20 for injecting molten resin, a heater fixing member 11 for fixing the heater 10, a first movement restricting member 12 that restricts the heater fixing member 11 from moving toward the root side in the axial direction of the nozzle 20, and a second movement restricting member 13 that restricts the heater fixing member 11 from moving toward the tip side in the axial direction of the nozzle 20.

Description

Technical Field

[0001] The present invention relates to a nozzle heater device and an injection molding machine.

Background Art

[0002] The heater of the nozzle of an injection molding machine may shift in the axial direction of the nozzle from a predetermined position (see FIG. 11(A)) when subjected to an external force or during detachment during cleaning or the like. For example, when the position of the heater shifts to the tip side in the axial direction of the nozzle (see FIG. 11(B)), the temperature detected in the region on the tip side of the nozzle by the thermocouple (temperature sensor) becomes high, and the temperature detected in the region on the base side in the axial direction of the nozzle becomes low. In this case, problems such as stringing, drooling, and cold slags are likely to occur. Also, for example, when the position of the heater shifts to the base side of the nozzle (see FIG. 11(C)), the temperature detected in the region on the base side of the nozzle becomes high, and the temperature detected in the region on the tip side of the nozzle becomes low. In this case, problems such as nozzle clogging due to solidification of the resin at the tip portion of the nozzle and carbonization of the resin in the region on the base side of the nozzle are likely to occur. Thus, the axial displacement of the heater may change the axial temperature distribution of the nozzle even if the set temperature is the same, which may cause molding defects. In contrast, Patent Document 1 discloses fixing the position of the temperature sensor by inserting a temperature sensor that penetrates the heater into the nozzle.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even if the position of the temperature sensor is fixed, if the heater position shifts in the axial direction of the nozzle, the temperature distribution changes, which can cause molding defects. Also, since thin thermocouples are sometimes used as temperature sensors, if shear force is applied to the temperature sensor by an external force, the temperature sensor can easily break.

[0005] The objective of the present invention is to suppress axial misalignment of the nozzle heater of an injection molding machine, which can cause molding defects and fracture of temperature sensors. [Means for solving the problem]

[0006] The nozzle heater device of the present invention, completed with this objective in mind, is characterized by comprising: a heater arranged to surround a nozzle for injecting molten resin; a heater fixing member for fixing the heater; a first movement restricting member that restricts the heater fixing member from moving toward the root side in the axial direction of the nozzle; and a second movement restricting member that restricts the heater fixing member from moving toward the tip side in the axial direction. Here, the first movement restricting member may be characterized by being a wall or step positioned between the cylinder located at the base and the heater fixing member. Furthermore, the second movement restricting member may be characterized by being a wall, step, or nut fixed in contact with the tip portion of the heater fixing member. Furthermore, the heater fixing member may be detachable by removing the second movement restricting member, and the heater fixing member may be positioned in the axial direction by attaching the second movement restricting member after attaching the heater fixing member to the nozzle, and sandwiching the heater fixing member between the first movement restricting member and the second movement restricting member. Furthermore, the second movement restricting member may be characterized by being a cylindrical member having a portion that surrounds the heater from the radial outside. The heater fixing member may also be characterized by having a thermocouple for measuring the temperature inside the nozzle, and a notch for passing the thermocouple through. Furthermore, the heater fixing member may be characterized by having multiple heaters fixed to it. Furthermore, the inner diameter of the heater fixing member may be approximately the same as the outer diameter of the nozzle. Furthermore, the heater fixing member may be characterized by being a member in which a plurality of rod-shaped members are fixed to an annular member. Furthermore, the injection molding machine of the present invention, completed for the purpose of this invention, is an injection molding machine equipped with a nozzle heater device, wherein the nozzle heater device comprises a heater arranged to surround a nozzle for injecting molten resin, a heater fixing member for fixing the heater, a first movement restricting member that restricts the heater fixing member from moving toward the root side in the axial direction of the nozzle, and a second movement restricting member that restricts the heater fixing member from moving toward the tip side in the axial direction. [Effects of the Invention]

[0007] According to the present invention, axial displacement of the nozzle heater of an injection molding machine can be suppressed. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing an example of the overall configuration of the nozzle heater device according to this embodiment. [Figure 2] This figure shows a modified example of the second movement restricting member that constitutes the nozzle heater device shown in Figure 1. [Figure 3] This figure shows a further modified example of the nozzle heater device shown in Figure 2. [Figure 4] This diagram illustrates an example of conventional technology in which spacers are placed between adjacent heaters. [Figure 5] (A) and (B) are diagrams showing modified examples of the heater fixing member that constitutes the nozzle heater device in Figure 1. [Figure 6](A) and (B) are diagrams showing modified examples of the heater and heater fixing member that constitute the nozzle heater device of Figure 1. [Figure 7] This figure shows modified examples of the heater and heater fixing member that constitute the nozzle heater device shown in Figure 1. [Figure 8] (A) is a diagram showing a modified example of the heater fixing member that constitutes the nozzle heater device in Figure 1. (B) is a diagram showing modified examples of the heater fixing member and the second movement restricting member that constitute the nozzle heater device in Figure 2. [Figure 9] This figure shows a specific example of the nozzle heater device shown in Figure 1. [Figure 10] This figure shows a specific example of the nozzle heater device shown in Figure 1. [Figure 11] Figures (A) through (C) illustrate the heater of a conventional injection molding machine nozzle. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described in detail below with reference to the attached drawings. <Configuration of Nozzle Heater Device 1> Figure 1 is a cross-sectional view showing an example of the overall configuration of the nozzle heater device 1 according to this embodiment. The nozzle heater device 1 shown in Figure 1 is a device that controls the temperature of a nozzle 20 mounted on an injection molding machine that performs injection molding using resin as the material. The nozzle 20 injects molten resin toward a mold (not shown) from an injection port 21 formed at the axial end of the nozzle. The axial base of the nozzle 20 (hereinafter simply referred to as "axial direction") is fixed to a cylindrical cylinder 30 that delivers molten resin toward the nozzle 20.

[0010] The nozzle heater device 1 has a cylindrical heater 10 arranged radially outside so as to surround the nozzle 20. Further, the nozzle heater device 1 has a cylindrical heater fixing member 11 arranged between the nozzle 20 and the heater 10 with the heater 10 fixed thereto. Further, the nozzle heater device 1 has a first movement restricting member 12 that restricts the heater fixing member 11 from moving toward the base side in the axial direction. Further, the nozzle heater device 1 has a second movement restricting member 13 that restricts the heater fixing member 11 from moving toward the tip side in the axial direction. Further, the nozzle heater device 1 has a thermocouple 14 that measures the temperature inside the nozzle 20.

[0011] 〔Heater fixing member 11〕 The heater fixing member 11 is a cylindrical member extending in the axial direction. The heater fixing member 11 is arranged radially outside the nozzle 20 with the heater 10 fixed to the circumferential surface thereof. The method of fixing the heater 10 to the heater fixing member 11 is not particularly limited. For example, the heater 10 is fixed to the heater fixing member 11 using a method such as adhesion or welding.

[0012] The inner diameter of the heater fixing member 11 is substantially the same as the outer diameter of the nozzle 20. If a gap is formed between the heater fixing member 11 and the nozzle 20, there may be a delay in temperature control and a decrease in the reaction rate. Therefore, in order to suppress the formation of a gap between the heater fixing member 11 and the nozzle 20, the heater fixing member 11 and the nozzle 20 may be press-fitted.

[0013] The surface 111 of the end portion of the heater fixing member 11 on the base side in the axial direction is in contact with the first movement restricting member 12. The surface 112 of the end portion of the heater fixing member 11 on the tip side in the axial direction is in contact with the second movement restricting member 13. Thereby, the heater fixing member 11 is axially positioned while being sandwiched between the first movement restricting member 12 and the second movement restricting member 13.

[0014] The heater fixing member 11 has a notch 113 for passing the thermocouple 14 through. Specifically, the notch 113 is formed at the axial root end of the heater fixing member 11. By forming the notch 113, even if the heater fixing member 11 is slid in the axial direction, the heater fixing member 11 can be smoothly attached and detached without interfering with the wiring of the thermocouple 14 attached to the nozzle 20 or the wiring of the heater 10 (not shown). The specific position and shape of the notch 113 will be described later with reference to Figure 9.

[0015] The heater 10 is fixed to the heater fixing member 11. As described above, the heater fixing member 11 is positioned in the axial direction while sandwiched between the first movement restricting member 12 and the second movement restricting member 13, so the heater 10 fixed to the heater fixing member 11 is also positioned at the same time.

[0016] The number of heaters 10 fixed to the heater fixing member 11 is not particularly limited. Multiple heaters 10 may be fixed to the heater fixing member 11. When the nozzle 20 is long in the axial direction, it may be difficult to control the temperature to a constant level with one thermocouple 14 per heater 10 unless the heater 10 is sufficiently long in the axial direction. For this reason, by controlling with multiple heaters 10 and multiple thermocouples 14, it becomes possible to control the nozzle 20 to a constant temperature. Specific examples of heater fixing members 11 to which multiple heaters 10 are fixed will be described later with reference to Figures 3 and 9.

[0017] The heater fixing member 11 is detachable when the second movement restricting member 13 is removed. Specifically, it can be removed by removing the second movement restricting member 13 and sliding the heater fixing member 11 towards the axial end. It can also be installed by sliding the heater fixing member 11 from the axial end towards the base.

[0018] [First movement restricting member 12] The first movement restricting member 12 is a cylindrical member positioned between the cylinder 30 and the heater fixing member 11. The first movement restricting member 12 is fixed to the cylinder 30. The surface 111 of the axial root end of the heater fixing member 11 is in contact with the first movement restricting member 12. As a result, the first movement restricting member 12 functions as a wall or step that restricts the axial movement of the heater fixing member 11 towards the root. In other words, the first movement restricting member 12 positions the heater fixing member 11 in the axial direction by sandwiching it between the second movement restricting member 13 and the heater fixing member 11.

[0019] [Second movement restricting member 13] The second movement restricting member 13 is fixed in a position that contacts the surface 112 of the axial end of the heater fixing member 11. The second movement restricting member 13 has a portion that sandwiches the heater fixing member 11 together with the first movement restricting member 12, and a portion that covers the outer circumferential surface of the heater 10. The method for fixing the second movement restricting member 13 is not particularly limited, but in the example in Figure 1, the second movement restricting member 13 is fixed to the first movement restricting member 12 by inserting a screw 15 into a screw hole that connects the first movement restricting member 12 and the second movement restricting member 13. As a result, the second movement restricting member 13 functions as a wall that restricts the movement of the heater fixing member 11 toward the axial end. In other words, the second movement restricting member 13 positions the heater fixing member 11 in the axial direction by sandwiching the heater fixing member 11 together with the first movement restricting member 12.

[0020] Since the second movement restricting member 13 has a portion that covers the outer surface of the heater 10, it also functions as a cover for the nozzle heater device 1. The function of the second movement restricting member 13 as a cover suppresses contamination by molten resin.

[0021] The second movement restricting member 13 has a notch 131 for passing the thermocouple 14 through. Specifically, the notch 131 is formed at the axial root end of the second movement restricting member 13. By forming the notch 131, the second movement restricting member 13 can be smoothly attached and detached by sliding it in the axial direction without interfering with the wiring of the thermocouple 14 attached to the nozzle 20 or the wiring of the heater 10. The specific position and shape of the notch 131 will be described later with reference to Figure 10.

[0022] The heater fixing member 11 to which the heater 10 is fixed and the second movement restricting member 13 may be integrated by joining them (adhesion, welding, etc.). In this case, the position of the heater 10 relative to the second movement restricting member 13 is fixed.

[0023] [Thermocouple 14] The thermocouple 14 is a temperature sensor that measures the temperature inside the nozzle 20. Here, in order to control the resin temperature as accurately as possible, the thermocouple 14 is installed near the molten resin inside the nozzle 20. That is, it is preferable that the thermocouple 14 is installed radially inward from the heater 10 and the heater fixing member 11. In this case, the thermocouple 14 is installed before the heater 10 and the heater fixing member 11.

[0024] <Example 1> Figure 2 shows a modified example of the second movement restricting member 13 that constitutes the nozzle heater device 1 in Figure 1. The configuration of the nozzle heater device 1 shown in Figure 2 is basically the same as the configuration shown in Figure 1, but there is a difference in the configuration of the second movement restricting member.

[0025] In other words, the second movement restricting member 13 in Figure 1 above is positioned to surround the heater 10 as described above, and therefore functions as a cover for the nozzle heater device 1. In contrast, the second movement restricting member 33 in Figure 2 is not positioned to surround the heater 10. Specifically, the second movement restricting member 33 is fixed in a position that contacts the surface 112 of the axial end of the heater fixing member 11, and functions only as a wall or step that restricts the movement of the heater fixing member 11 toward the axial end. The shape of the second movement restricting member 33 is not particularly limited and may be composed of an annular or cylindrical member.

[0026] The method for fixing the second movement restricting member 33 is not particularly limited. For example, the second movement restricting member 33 may be made of a nut, and a screw mechanism for screwing into the nut may be formed on the axial end side of the heater fixing member 11. In this case, the second movement restricting member 33, which is a nut, is fixed to the nozzle 20 in contact with the surface 112 of the end on the tip side of the heater fixing member 11.

[0027] <Modification 2> Figure 3 shows a further modified example of the nozzle heater device 1 shown in Figure 2. Figure 4 illustrates an example of a conventional technique in which a spacer is placed between adjacent heaters. The configuration of the nozzle heater device 1 shown in Figure 3 is basically the same as the configuration shown in Figure 2, but the number of heaters 10 is different. That is, in the configuration shown in Figure 2 there is one heater 10, but in the configuration shown in Figure 3 there are two heaters 10-1 and 10-2.

[0028] As shown in Figure 4, conventionally, when multiple heaters are arranged in a nozzle, the position of the heaters is restricted by placing spacers between adjacent heaters. In contrast, in the nozzle heater device 1 shown in Figure 3, heaters 10-1 and 10-2 are fixed to the heater fixing member 11 and their axial positioning is achieved. Therefore, it is no longer necessary to place spacers between heaters as in the conventional method.

[0029] <Variation 3> Figures 5(A) and (B) show modified examples of the heater fixing member 11 that constitutes the nozzle heater device 1 in Figure 1. The heater fixing member 11 that constitutes the nozzle heater device 1 shown in Figure 1 above is a cylindrical member that extends in the axial direction, but is not limited to this. The heater fixing member according to the present invention only needs to be shaped along the nozzle 20 and be able to fix the heater 10, so it may be shaped like the heater fixing member 51 shown in Figures 5(A) and (B), for example.

[0030] Figure 5(A) shows the heater fixing member 51 in an axial view. Figure 5(B) shows a perspective view of the heater fixing member 51. The heater fixing member 51 consists of an annular member 511 to which a plurality of rod-shaped members 512 are fixed at intervals. The axial root-side surfaces 513 of the plurality of rod-shaped members 512 are in contact with the first movement restricting member 12 (see Figure 1). In addition, the axial tip-side surface 514 of the annular member 511 is in contact with the second movement restricting member 13 (see Figure 1). As a result, the heater fixing member 51 is fixed in a state sandwiched between the first movement restricting member 12 and the second movement restricting member 13.

[0031] One or more heaters 10 (see Figure 1) are fixed to the radially outer side of the heater fixing member 51. This positions the heaters 10 in the axial direction. The method for fixing the heaters 10 to the heater fixing member 51 is not particularly limited. For example, the heaters 10 can be fixed to the heater fixing member 51 using methods such as adhesive bonding or welding.

[0032] The multiple rod-shaped members 512 that make up the heater fixing member 51 are arranged at intervals, so that a space is formed between adjacent rod-shaped members 512. This space allows the heater fixing member 51 to be smoothly attached and detached without interfering with the wiring of the thermocouple 14 (see Figure 1) attached to the nozzle 20 or the wiring of the heater 10, even when the heater fixing member 51 is slid in the axial direction.

[0033] <Modification 4> Figures 6(A) and (B) show modified examples of the heater 10 and heater fixing member 11 that constitute the nozzle heater device 1 of Figure 1. The heater fixing member according to the present invention is shaped to follow the shape of the nozzle 20 and only needs to be able to fix the heater; therefore, it may have a shape such as the heater fixing member 61 shown in Figures 6(A) and (B).

[0034] Figure 6(A) shows a cross-sectional view of a cylindrical heater fixing member 61, on which the heater 40 is arranged, cut in the radial direction. Figure 6(B) shows a cross-sectional view of the heater fixing member 61, on which the heater 40 is arranged, cut in the axial direction. Grooves or the like are formed on the inner wall surface of the heater fixing member 61 in the radial direction, and the annular heater 40 is arranged in these grooves or the like. Multiple heaters 40 are arranged at intervals along the axial direction of the heater fixing member 61.

[0035] The axial base surface 611 of the heater fixing member 61 contacts the first movement restricting member 12 (see Figure 1). The axial tip surface 612 of the heater fixing member 61 contacts the second movement restricting member 13 (see Figure 1). As a result, the heater fixing member 61 is fixed in place, sandwiched between the first movement restricting member 12 and the second movement restricting member 13. Simultaneously, the axial positioning of the multiple heaters 40 is achieved.

[0036] <Modification 5> Figure 7 shows a modified example of the heater 10 and heater fixing member 11 that constitute the nozzle heater device 1 of Figure 1. The heater fixing member according to the present invention is shaped to conform to the nozzle 20 and only needs to be able to fix the heater; therefore, it may be divisible and separable, for example, as shown in Figure 7, for the heater fixing member 71.

[0037] Figure 7 shows a perspective view of the heater fixing member 71, on which the heater 50 is positioned on the radially outer surface. When the heater fixing member 71 is attached to the nozzle 20, it takes on a cylindrical shape. Therefore, the axial base surface 711 of the heater fixing member 71 contacts the first movement restricting member 12 (see Figure 1). Also, the axial tip surface 712 of the heater fixing member 71 contacts the second movement restricting member 13 (see Figure 1). As a result, the heater fixing member 71 is fixed in place, sandwiched between the first movement restricting member 12 and the second movement restricting member 13. At the same time, the axial positioning of the heater 50 is achieved.

[0038] The heater fixing member 71 can be separated into two axial parts together with the heater 50, as shown in Figure 7, for maintenance purposes. This configuration eliminates the need to slide the heater fixing member 71 when attaching or detaching it from the nozzle 20. However, since the wiring for the thermocouple 14 and the wiring for the heater 10 need to be connected to both of the two separated heater fixing member 71, a configuration that does not involve separation is preferable in this respect.

[0039] <Variation 6> Figure 8(A) shows a modified example of the heater fixing member 11 that constitutes the nozzle heater device 1 in Figure 1. The heater fixing member according to the present invention is shaped to conform to the nozzle 20 and only needs to be able to fix the heater. For example, as shown in Figure 8(A), the heater fixing member 11 has a rounded shape on the axial root side surface 111 and the axial tip side surface 112. Even if surfaces 111 and 112 have a rounded shape, a part of surface 111 makes point contact with the first movement restricting member 12 (see Figure 1), and a part of surface 112 makes point contact with the second movement restricting member 13 (see Figure 1). As a result, the heater fixing member 11 is fixed in a state sandwiched between the first movement restricting member 12 and the second movement restricting member 13.

[0040] <Example 7> Figure 8(B) shows a modified example of the heater fixing member 11 and the second movement restricting member 13 that constitute the nozzle heater device 1 in Figure 2. The heater fixing member according to the present invention is shaped to conform to the nozzle 20 and only needs to be able to fix the heater. Furthermore, the second movement restricting member according to the present invention only needs to be fixed in contact with the axial end portion of the heater fixing member. For this reason, each of the heater fixing member and the second movement restricting member according to the present invention may have a shape such as the heater fixing member 11 and the second movement restricting member 33 shown in Figure 8(B).

[0041] Specifically, a protrusion 114 projecting radially outward is formed near the axial end of the heater fixing member 11 shown in Figure 8(B). The second movement restricting member 33 has a lid-like shape that covers the axial end of the heater fixing member 11 and is fixed in contact with the protrusion 114 of the heater fixing member 11. At this time, the axial end surface of the heater fixing member 11 does not contact the second movement restricting member 33, but the protrusion 114 contacts the second movement restricting member 33. Therefore, the heater fixing member 11 is fixed sandwiched between the first movement restricting member 12 and the second movement restricting member 13. At the same time, the axial positioning of the heater 10 is achieved. Note that the method for forming the protrusion 114 on the heater fixing member 11 is not particularly limited; an annular member may be joined to the heater fixing member 11 using a method such as welding, or the protrusion 114 may be integrally molded as part of the heater fixing member 11.

[0042] <Specific example> Figures 9 and 10 show specific examples of the nozzle heater device 1 shown in Figure 1. Note that Figure 9 shows the state before the second movement restricting member 13 is attached. As shown in Figure 9, the nozzle heater device 1 has a heater fixing member 11. Two heaters 10-1 and 10-2 are wound around the heater fixing member 11. In this way, heaters 10-1 and 10-2 are fixed to the heater fixing member 11. The nozzle heater device 1 also has a thermocouple 14 for measuring the internal temperature of the nozzle 20. The thermocouple 14 is positioned in an axially extending groove 25 formed on the surface of the nozzle 20. Therefore, the thermocouple 14 does not come into contact with the radially inner surface of the heater fixing member 11. A screw mechanism 23 and a screw mechanism 31 are provided at the axial root side of the nozzle 20 and the axial tip side of the cylinder 30, respectively, and the nozzle 20 is fixed to the cylinder 30 by screwing these together.

[0043] Furthermore, as shown in Figure 10, the nozzle heater device 1 has a first movement restricting member 12 that restricts the heater fixing member 11 from moving axially towards the root. The surface 111 of the axial root end of the heater fixing member 11 shown in Figure 9 is in contact with the first movement restricting member 12. As a result, the first movement restricting member 12 functions as a wall or step that restricts the heater fixing member 11 from moving axially towards the root. The first movement restricting member 12 has a screw hole 16 for fixing the second movement restricting member 13 with a screw 15.

[0044] Furthermore, the nozzle heater device 1 has a second movement restricting member 13 that restricts the heater fixing member 11 from moving toward the axial tip side of the nozzle 20. The second movement restricting member 13 is fixed in a position that contacts the surface 112 (see Figure 9) of the axial tip end of the heater fixing member 11. As a result, the second movement restricting member 13 functions as a wall or step that restricts the heater fixing member 11 from moving toward the axial tip side. The second movement restricting member 13 is fixed to the first movement restricting member 12 by a screw 15.

[0045] The second movement restricting member 13 is positioned radially outward, surrounding the heaters 10-1 and 10-2. Therefore, the second movement restricting member 13 also functions as a cover for the nozzle heater device 1. In the examples shown in Figures 9 and 10, a screw mechanism 23 is provided at the axial tip end of the nozzle 20. The second movement restricting member 13 is firmly fixed by screwing a nut 24 onto the screw mechanism 23. However, since the second movement restricting member 13 is fixed to the first movement restricting member 12 by a screw 15, the screw mechanism 23 and nut 24 are not essential components.

[0046] As shown in Figure 9, a notch 113 is formed at the axial root end of the heater fixing member 11. Also, as shown in Figure 10, a notch 131 is formed at the axial root end of the second movement restricting member 13. Heaters 10-1 and 10-2, and the thermocouple 14 are positioned radially inside and outside the second movement restricting member 13 via the notches 113 and 131.

[0047] In summary, the nozzle heater device 1 according to this embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the nozzle heater device 1 is a nozzle heater device having a heater 10 arranged to surround a nozzle 20 for injecting molten resin, a heater fixing member 11 for fixing the heater 10, a first movement restricting member 12 that restricts the heater fixing member 11 from moving toward the root side in the axial direction, and a second movement restricting member 13 that restricts the heater fixing member 11 from moving toward the tip side in the axial direction.

[0048] As a result, the first movement restricting member 12 and the second movement restricting member 13 restrict the axial movement of the heater fixing member 11, thereby suppressing axial displacement of the heater 10 of the injection molding machine nozzle 20, which can cause molding defects and breakage of the thermocouple 14. In addition, since the position of the heater 10 does not change before and after attachment and detachment of the heater 10, cleaning of the nozzle 20 and heater 10 becomes easier. Furthermore, even if there are multiple injection molding machines, the heater 10 can be placed in the same position, thus suppressing temperature differences of the nozzle 20 between the machines.

[0049] Here, the first movement restricting member 12 may be characterized by being a wall or step positioned between the cylinder 30 and the heater fixing member 11, which are located on the axial root side. This restricts the heater fixing member 11 from moving towards the root in the axial direction.

[0050] Furthermore, the second movement restricting member 13 may be characterized by being a wall, step, or nut fixed in contact with the axial end surface 112 of the heater fixing member 11. This restricts the heater fixing member 11 from moving towards the tip in the axial direction.

[0051] Furthermore, the heater fixing member 11 may be detachable by removing the second movement restricting member 13, and the heater fixing member 11 may be positioned in the axial direction by attaching the second movement restricting member 13 after attaching the heater fixing member 11 to the nozzle 20, and then sandwiching the heater fixing member 11 between the first movement restricting member 12 and the second movement restricting member 13. This allows the heater fixing member 11 to be attached and detached by removing the second movement restricting member 13, thus improving maintainability.

[0052] Furthermore, the second movement restricting member 13 may be characterized by being a cylindrical member having a portion that surrounds the heater 10 from the radial outside. As a result, the second movement restricting member 13 functions as a cover, thus suppressing contamination by molten resin.

[0053] Furthermore, the heater fixing member 11 may be characterized by having a thermocouple 14 for measuring the temperature inside the nozzle 20, and a notch 113 for passing the thermocouple 14 through. As a result, by sliding the heater fixing member 11 toward the axial end, the second movement restricting member 13 and the heater fixing member 11 can be smoothly attached and detached without interfering with the wiring of the thermocouple 14 or the heater 10.

[0054] Furthermore, the heater fixing member 11 may be characterized by having multiple heaters 10 (for example, heaters 10-1 and 10-2 in Figure 3) fixed to it. As a result, even if the nozzle 20 is long in the axial direction, the nozzle 20 can be controlled to a constant temperature by arranging multiple heaters 10, and there is no need to provide spacers between the heaters 10.

[0055] Furthermore, the inner diameter of the heater fixing member 11 may be approximately the same as the outer diameter of the nozzle 20. This prevents the formation of a gap between the heater fixing member 11 and the nozzle 20, thereby suppressing delays in temperature control and a decrease in reaction rate.

[0056] Furthermore, the heater fixing member 51 may be characterized by being a member in which a plurality of rod-shaped members 512 are fixed to an annular member 511. As a result, a space is formed between adjacent rod-shaped members 512, allowing the heater fixing member 51 to be smoothly attached and detached by sliding it towards the axial end without interfering with the wiring of the thermocouple 14 or heater 10.

[0057] Furthermore, the injection molding machine according to the first embodiment only needs to have the following configuration, and various different embodiments can be adopted. In other words, the injection molding machine according to the first embodiment is an injection molding machine equipped with a nozzle heater device 1, wherein the nozzle heater device 1 comprises a heater 10 arranged to surround a nozzle 20 for injecting molten resin, a heater fixing member 11 for fixing the heater 10, a first movement restricting member 12 that restricts the heater fixing member 11 from moving toward the root side in the axial direction, and a second movement restricting member 13 that restricts the heater fixing member 11 from moving toward the tip side in the axial direction.

[0058] <Other> Although this embodiment has been described above, the present invention is not limited to the embodiment described above. Furthermore, the effects of the present invention are not limited to those described in this embodiment.

[0059] For example, the notches 113 and 131 each form a space for passing the wiring of the thermocouple 14 and the heater 10, but since it is sufficient to form a space for passing the wiring, they may be holes instead of notches. Alternatively, the heater fixing member 11 and the second movement restricting member 13 may be configured in such a way that one or more phases of the radial cross-section are completely cut off (i.e., a slit extending in the axial direction is formed). Note that the heater fixing member 51 in the above-described modified example 3 (Figure 5(B)) is an example of a configuration in which multiple phases of the radial cross-section are completely cut off. [Explanation of symbols]

[0060] 1…Nozzle heater device, 10, 10-1, 10-2, 40, 50…Heater, 11, 51, 61, 71…Heater fixing member, 12…First movement restricting member, 13, 33…Second movement restricting member, 14…Thermocouple, 15…Screw, 16…Screw hole, 20…Nozzle, 21…Injection port, 22…Injection port, 23, 31…Screw mechanism, 24…Nut, 25…Groove, 30…Cylinder, 111, 112, 513, 514, 611, 612, 711, 712…Surface, 113, 131…Notch, 511…Annular member, 512…Rod-shaped member

Claims

1. A heater is positioned to surround the nozzle from which the molten resin is injected, A heater fixing member for fixing the aforementioned heater, A first movement restricting member that restricts the heater fixing member from moving toward the axial root side of the nozzle, A second movement restricting member that restricts the heater fixing member from moving toward the axial end, A nozzle heater device characterized by having the following.

2. The first movement restricting member is characterized by being a wall or step positioned between the cylinder located at the base and the heater fixing member. The nozzle heater device according to claim 1.

3. The second movement restricting member is characterized by being a wall, step, or nut fixed in contact with the axial end portion of the heater fixing member. The nozzle heater device according to claim 1.

4. The heater fixing member is detachable by removing the second movement restricting member. The heater fixing member is attached to the nozzle, and then the second movement restricting member is attached, thereby positioning the heater fixing member in the axial direction by sandwiching it between the first movement restricting member and the second movement restricting member. The nozzle heater device according to claim 1.

5. The second movement restricting member is characterized by being a cylindrical member having a portion that surrounds the heater from the radial outside, The nozzle heater device according to claim 1.

6. The nozzle further includes a thermocouple for measuring the temperature inside the nozzle, The heater fixing member is characterized by having a notch formed therein for passing the thermocouple through. The nozzle heater device according to claim 5.

7. The heater fixing member is characterized in that a plurality of the heaters are fixed to it. The nozzle heater device according to claim 1.

8. The inner diameter of the heater fixing member is approximately the same as the outer diameter of the nozzle. The nozzle heater device according to claim 1.

9. The heater fixing member is characterized by being a member in which a plurality of rod-shaped members are fixed to an annular member. The nozzle heater device according to claim 1.

10. An injection molding machine equipped with a nozzle heater device, The nozzle heater device, A heater is positioned to surround the nozzle from which the molten resin is injected, A heater fixing member for fixing the aforementioned heater, A first movement restricting member that restricts the heater fixing member from moving toward the axial root side of the nozzle, A second movement restricting member that restricts the heater fixing member from moving toward the axial end, An injection molding machine characterized by having [a certain feature].

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