Method for positioning rotational position of injection nozzle, and injection nozzle

Abstract

To provide a positioning method for mounting an injection nozzle in an appropriate rotational position relative to a heating cylinder.SOLUTION: An injection nozzle (5) is fixed with loosening a mounting and fixing member (28) that attaches the nozzle to a heating cylinder (19) to allow rotation and with tightening the nozzle to restrict rotation. Form a notch (43) extending in the axial direction on the outer circumference of a body (36) of the injection nozzle (5). When fixing the injection nozzle (5) to the heating cylinder (19), a positioning member (57) is provided with its relative movement to the heating cylinder (19) restricted, and the positioning member (57) is slidably engaged against the notch (43). The mounting and fixing member (28) is tightened.SELECTED DRAWING: Figure 6C

Description

[Technical field]

[0001] The present invention relates to a method for determining the rotational position of an injection nozzle provided on a heating cylinder with respect to the heating cylinder, and to an injection nozzle, an injection device, or an injection molding machine. [Background technology]

[0002] The injection device of the injection molding machine includes a heating cylinder and a screw inserted in the heating cylinder, and an injection nozzle is provided at the tip of the heating cylinder. The injection nozzle is attached to the heating cylinder by a predetermined attachment member. An example of the attachment member is a pressing member, i.e., a cylinder head, as described in Patent Document 1. The injection nozzle has an enlarged flange portion at its rear end, and the cylinder head is configured to press this flange portion against the heating cylinder to fix the injection nozzle to the heating cylinder.

[0003] Incidentally, the injection nozzle described in Patent Document 1 constitutes a shut-off nozzle by a needle valve and a drive mechanism for driving the needle valve. That is, the injection nozzle has a needle hole that reaches the resin flow path inside at an angle from the outer peripheral surface, and the needle valve is inserted into the needle hole so as to be freely advanced and retreated, and the injection flow path is opened and closed by driving the needle valve. In an injection nozzle equipped with such a needle valve, it is necessary to align the needle hole and the needle valve, and it is necessary to fix the injection nozzle at an appropriate rotational position relative to the heating cylinder. Therefore, in the injection nozzle described in Patent Document 1, the rotational position is determined by a positioning pin. Specifically, a pin hole is formed in the flange portion of the injection nozzle, and a pin insertion hole is formed in the holding member, i.e., the cylinder head. Then, a positioning pin is inserted into the pin insertion hole through the pin insertion hole, and the rotational position of the injection nozzle is determined. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-30519 A Summary of the Invention [Problem to be solved by the invention]

[0005] If a positioning pin is provided, it is possible to position the injection nozzle at an appropriate rotational position relative to the heating cylinder. However, when a positioning pin is provided, it is necessary to drill a pin hole in the flange portion of the injection nozzle. In order to drill a pin hole, the flange portion needs to be wide enough. If the width of the flange portion is small, it becomes difficult to drill a pin hole. In particular, in the case of a small injection molding machine, the injection nozzle is relatively small, making it difficult to drill a pin hole.

[0006] In the present disclosure, a positioning method is provided that allows the injection nozzle to be attached in a suitable rotational position relative to the heating cylinder.

[0007] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0008] The injection nozzle has a flange portion with an enlarged diameter at the rear end, and is attached to the heating cylinder by a mounting and fixing member that holds down the flange portion. When the mounting and fixing member is loosened, the injection nozzle is allowed to rotate relative to the heating cylinder, and when it is tightened, the rotation is restricted. In the present disclosure, a notch extending in the axial direction is formed on the outer circumferential surface of the body of the injection nozzle. When the injection nozzle is fixed to the heating cylinder, a predetermined positioning member is provided in a state in which its relative movement with respect to the heating cylinder is restricted. The positioning member is then slidably engaged with the notch portion to restrict the rotation of the injection nozzle, and the mounting and fixing member is tightened to the heating cylinder. Effect of the Invention

[0009] The present disclosure allows the injection nozzle to be positioned and attached at an appropriate rotational position relative to the heating cylinder. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing an injection molding machine according to a first embodiment. [Diagram 2] 2 is a front cross-sectional view showing a part of the injection device and a shut-off nozzle according to the first embodiment. FIG. [Diagram 3] FIG. 2 is a perspective view of an injection nozzle according to the first embodiment. [Figure 4] FIG. 2 is a perspective view of a mounting and fixing member according to the first embodiment. [Diagram 5] FIG. 2 is a perspective view of a positioning jig according to the first embodiment. [Figure 6A] 2 is a front cross-sectional view showing a part of the injection device and a shut-off nozzle according to the first embodiment. FIG. [Figure 6B] 2 is a front cross-sectional view showing a part of the injection device, a shut-off nozzle, and a positioning jig according to the first embodiment. FIG. [Figure 6C] 2 is a front cross-sectional view showing a part of the injection device, a shut-off nozzle, and a positioning jig according to the first embodiment. FIG. [Figure 7] FIG. 11 is a front cross-sectional view showing a part of an injection device and a shut-off nozzle according to a comparative example. [Figure 8] FIG. 11 is a front cross-sectional view showing a part of an injection device, a shut-off nozzle, and a positioning jig according to a second embodiment. [Figure 9A] FIG. 11 is a perspective view of an injection nozzle according to a third embodiment. [Figure 9B] FIG. 11 is a perspective view of a positioning jig according to a third embodiment. [Figure 10] FIG. 4 is a front cross-sectional view of a part of an injection device and a shut-off nozzle according to a first modified example of the first embodiment. [Figure 11] 11 is a front cross-sectional view showing a part of an injection device according to a second modified example of the first embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Specific embodiments will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments. In order to clarify the description, the following description and drawings are appropriately simplified. In each drawing, the same elements are given the same reference numerals, and duplicated descriptions are omitted as necessary. In addition, hatching is omitted in some parts to avoid cluttering the drawings.

[0012] [First embodiment] <Injection molding machine> As shown in Fig. 1, the injection molding machine 1 according to the first embodiment is a so-called vertical injection molding machine. A shut-off nozzle 6, which will be described in detail later with reference to Fig. 2, is provided in this vertical injection molding machine, but it can also be provided in a horizontal injection molding machine, and the type of injection molding machine does not matter. The injection molding machine 1 according to the first embodiment includes a toggle-type mold clamping device 2, an injection device 3, and a control device 4. The control device 4 is configured to control the mold clamping device 2, the injection device 3, etc.

[0013] <Mold clamping device> The mold clamping device 2 is a so-called vertical mold clamping device, and includes a fixed platen 9 fixed to a bed 7, an upper movable platen 10 provided above the fixed platen 9, and a lower movable platen 11 provided within the bed 7. The upper movable platen 10 and the lower movable platen 11 are connected by three tie bars 12, 12, .... A toggle mechanism 14 is provided between the lower movable platen 11 and the fixed platen 9, and a turntable 15 is provided above the fixed platen 9. An upper mold 17 is provided on the upper movable platen 10, and a lower mold 18 is provided on the turntable 15. When the toggle mechanism 14 is driven, the upper mold 17 and the lower mold 18 are opened and closed.

[0014] <Injection device> The injection unit 3 is provided on the upper movable platen 10 of the mold clamping unit 2. The injection unit 3 includes a heating cylinder 19, a screw 20 provided in the heating cylinder 19, a screw driving unit 22, and a lifting unit 23 that lifts and lowers the entire injection unit 3. The heating cylinder 19 is provided with a shut-off nozzle 6 as shown in Fig. 2, which will be described in detail below. The heating cylinder 19 is provided with heaters 25, 25, ... (see Fig. 2).

[0015] <Shut-off nozzle> 2, the shut-off nozzle 6 includes an injection nozzle 5, a needle valve 29, etc. A fixing member 31 that is fixed to the heating cylinder 19 is provided on the heating cylinder 19, and a bracket 32 ​​is provided on this fixing member 31. An actuator that drives the needle valve 29, i.e., a drive mechanism 34, has a rear end portion that is rotatable relative to the bracket 32. The injection nozzle 5 is attached to the heating cylinder 19 by a mounting member 28 that will be described later.

[0016] <Injection nozzle> As shown in Fig. 3, the injection nozzle 5 according to the first embodiment includes a cylindrical body 36 and a flange portion 37 with an expanded diameter at the rear end. An attachment member 28 (see Fig. 2), which will be described later, presses the flange portion 37 against the heating cylinder 19 to fix the injection nozzle 5 to the heating cylinder 19. A resin flow path 38 is formed in the axial center of the injection nozzle 5, and resin is injected from an injection port 39 at the tip of the body 36. An oblique needle hole 41 is formed in the body 36, which extends from its outer circumferential surface to the resin flow path 38. As shown in Fig. 2, the needle valve 29 is inserted into the needle hole 41, and the resin flow path 38 is opened and closed when the needle valve 29 is moved forward and backward by the drive mechanism 34.

[0017] The injection nozzle 5 according to the first embodiment has a structure characteristic of the present disclosure. Specifically, as shown in FIG. 3, a notch, i.e., a groove 43 extending in the axial direction is formed on the outer circumferential surface of the body 36. When the injection nozzle 5 is attached to the heating cylinder 19 by the attachment and fastening member 28 (see FIG. 4), which will be described in detail below, if the attachment and fastening member 28 is loosened, the injection nozzle 5 will rotate relative to the heating cylinder 19. This makes it difficult to fix the injection nozzle 5 to the heating cylinder 19 at an appropriate rotational position. As will be described later, the groove 43 is a structure necessary for determining the rotational position of the injection nozzle 5.

[0018] <Mounting and fixing parts> As shown in Fig. 4, the mounting and fixing member 28 according to the first embodiment includes a cylindrical portion 45 and a hexagonal nut-shaped fastening portion 46, and has a through hole 47 formed in the axial direction. The through hole 47 is for inserting the body portion 36 of the injection nozzle 5 (see Fig. 3). A male thread 49 is formed on the outer circumferential surface of the cylindrical portion 45. As shown in Fig. 2, an axial hole 51 with a female thread is formed at the tip of the heating cylinder 19. The male thread 49 is screwed into the female thread of the hole 51, and the mounting and fixing member 28 is fastened, whereby the injection nozzle 5 is attached to the heating cylinder 19.

[0019] <Positioning jig> A positioning jig 55 according to the first embodiment will be described with reference to Figure 5. The positioning jig 55 according to the first embodiment is a jig for determining the rotational position of the injection nozzle 5 relative to the heating cylinder 19. The positioning jig 55 is composed of a base portion 56 and a pin 57 provided on the base portion 56. As will be described next, the pin 57 is a positioning member that engages with a groove portion 43 of the injection nozzle 5 (see Figure 3) to determine the rotational position of the injection nozzle 5. The base portion 56 is provided with bolt holes 59, 59, ... for fixing to a fixing member 31 fixed to the heating cylinder 19 (see Figure 2).

[0020] <Shut-off nozzle setup> A method of attaching the injection nozzle 5 to the heating cylinder 19 (see FIG. 2) and setting up the shut-off nozzle 6 will be described. As shown in FIG. 6A, the mounting member 28 is provided on the injection nozzle 5. That is, the body 36 of the injection nozzle 5 is inserted into the through hole 47 of the mounting member 28. The end face of the cylindrical portion 45 of the mounting member 28 is brought into contact with the flange portion 37 of the injection nozzle 5, and the male thread 49 of the cylindrical portion 45 of the mounting member 28 is screwed into the female thread of the hole 51 of the heating cylinder 19. Then, the result is as shown in FIG. 6B. At this time, the male thread 49 of the mounting member 28 is loosened relative to the female thread of the hole 51.

[0021] As shown in FIG. 6B, the positioning jig 55 according to the first embodiment is fixed to the fixed member 31. Specifically, the base portion 56 is fixed to the fixed member 31 by bolts 61, 61, .... This prevents the positioning member, i.e., the pin 57, from moving relative to the heating cylinder 19. When the positioning jig 55 is fixed to the fixed member 31, the rotational position of the injection nozzle 5 is adjusted so that the tip of the pin 57 is inserted into the groove portion 43. In other words, the pin 57, which is the positioning member, is engaged with the groove portion 43, which is the notch portion. When this state is reached, the rotational position of the injection nozzle 5 is appropriate.

[0022] The fastening portion 46 of the mounting member 28 is engaged with a tool such as a spanner to rotate the mounting member 28. Then, the mounting member 28 moves upward together with the injection nozzle 5. The mounting member 28 rotates, but the rotational position of the injection nozzle 5 relative to the heating cylinder 19 does not change because the groove 43 and the pin 57 are engaged and the rotation of the injection nozzle 5 is restricted. When the mounting member 28 is fastened, as shown in FIG. 6C, the attachment of the injection nozzle 5 to the heating cylinder 19 is completed. Note that the axial length of the groove 43 of the injection nozzle 5 is sufficient if it is one or several pitches of the male screw 49 of the cylindrical portion 45 of the mounting member 28, but it may be approximately the same length as the male screw 49. It is sufficient that the pin 57 is kept engaged with the groove 43 until the fastening of the mounting member 28 is completed.

[0023] After the attachment of the injection nozzle 5 to the heating cylinder 19 is completed, the positioning jig 55 is removed from the fixing member 31. Since the rotational position of the injection nozzle 5 relative to the heating cylinder 19 is properly positioned, the needle valve 29 can be inserted into the needle hole 41. This results in the state shown in Fig. 2. The setup of the shut-off nozzle 6 is completed.

[0024] [Comparative Example] A method for positioning the rotational position of the injection nozzle 5 without using the positioning jig 55 will be described using a comparative example. As shown in Fig. 7, the injection device 3X according to the comparative example is configured in the same manner as the injection device 3 according to the first embodiment (see Fig. 2) with only some differences in configuration. Therefore, the same reference numbers are used for the same components and their description will be omitted.

[0025] In the injection device 3X according to the comparative example, the heating cylinder 19X and the injection nozzle 5X are different from those in the first embodiment. The heating cylinder 19X has an alignment pin 63 embedded in the bottom of a hole 51 formed at the tip. The injection nozzle 5X has a pin hole 64 formed in the end face at the rear end. When the mounting and fixing member 28 is rotated and fastened to the heating cylinder 19, the rotational position of the injection nozzle 5X is adjusted so that the alignment pin 63 is inserted into the pin hole 64. This allows the rotational position of the injection nozzle 5X relative to the heating cylinder 19X to be positioned. In the injection device 3X according to the comparative example, the rotational position of the injection nozzle 5X can be positioned in this way, but when the injection nozzle 5X is small, it is difficult to open the pin hole 64. Furthermore, if the alignment pin 63 embedded in the heating cylinder 19X is bent, there is a problem that it must be replaced.

[0026] [Second embodiment] <Injection molding machine> The injection molding machine according to the second embodiment has the same clamping device and control device as the first embodiment, so the description of these will be omitted. Figure 8 shows a part of an injection unit 3X according to the second embodiment, and although some configurations are different, most of the members are configured in the same way as the injection unit 3 according to the first embodiment (see Figure 2). The same members are given the same reference numbers and the description will be omitted.

[0027] <Injection unit, injection nozzle> In the injection device 3A according to the second embodiment, an extension fixing member 67 is attached to the fixing member 31 fixed to the heating cylinder 19. The positioning jig 55 is attached to the extension fixing member 67, and the positioning member, i.e., the pin 57, can be restricted from moving relative to the heating cylinder 19. The injection nozzle 5A in the second embodiment is also partially different from that in the first embodiment. The difference is the position of the notch portion, i.e., the groove portion 43. When the injection nozzle 5X is viewed from the axial direction, i.e., the direction of the arrow 68, the needle hole 41 and the groove portion 43 are arranged at positions spaced apart by 90 degrees in the circumferential direction. Similarly, the needle valve 29 and the positioning jig 55 are also arranged at positions spaced apart by 90 degrees. Therefore, the second embodiment has the advantage that the positioning jig 55 does not interfere with the needle valve 29 when attached.

[0028] [Third embodiment] <Injection molding machine> The injection molding machine according to the third embodiment has the same clamping device, injection device, and control device as the first embodiment, so a description of these will be omitted. The third embodiment differs from the first embodiment in the injection nozzle 5B (see FIG. 9A) and the positioning jig 55B (see FIG. 9B). These will be described. Note that, regarding the injection nozzle 5B and the positioning jig 55B, the same members as the injection nozzle 5 (see FIG. 3) and the positioning jig 55 (see FIG. 5) according to the first embodiment are given the same reference numbers and a description thereof will be omitted.

[0029] <Injection nozzle> As shown in Fig. 9A, the injection nozzle 5B according to the third embodiment does not have the groove portion 43 (see Fig. 3) formed in the first embodiment. Instead of the groove portion 43, another cutout portion is formed. Specifically, a pair of parallel flat portions 70, 70 are formed at both ends in the diameter direction of the body portion 36.

[0030] <Positioning jig> As shown in Fig. 9B, a positioning jig 55B according to the third embodiment does not have the pin 57 (see Fig. 5) that was provided in the first embodiment. Instead of the pin 57, another positioning member is provided. Specifically, a pair of guide members 71, 71 are provided. These guide members 71, 71 are arranged to sandwich a pair of flat surfaces 70 of the injection nozzle 5B (see Fig. 9A) between them, thereby positioning the rotational position of the injection nozzle 5B.

[0031] [Modification 1 of the first embodiment] The first embodiment can be modified in various ways. For example, the mounting and fixing member 28 that fixes the injection nozzle 5 (see FIG. 2) to the heating cylinder 19 can be modified. FIG. 10 shows an injection device 3C according to a first modified example of the first embodiment. In this modified example, the mounting and fixing member 74 is a cylinder head. The heating cylinder 19 is provided with a block 75, and the injection nozzle 5 is provided on the heating cylinder 19 such that the flange portion 37 is pressed against the block 75 by the mounting and fixing member 74. The mounting and fixing member 74 is fastened to the heating cylinder 19 by bolts 76, 76. In this first modified example as well, it is necessary to align the needle valve 29 of the shut-off nozzle 6 with the needle hole 41, and the rotational position of the injection nozzle 5 is aligned by the groove portion 43 of the injection nozzle 5 and the positioning jig 55 (see FIG. 5) already described.

[0032] [Modification 2 of the First Embodiment] In the first embodiment, the shut-off nozzle 6 can be removed. FIG. 11 shows an injection device 3D according to a second modification, which includes an injection nozzle 5D that does not include a shut-off nozzle 6. In the injection device 3D according to the second modification, the injection nozzle 5D is attached to the heating cylinder 19 by a mounting member 74 made of a cylinder head, as in the first modification. In the injection device 3D according to the second modification, a temperature sensor 80 is provided to measure the temperature in the vicinity of the rear end of the injection nozzle 5D. The temperature sensor 80 is inserted into a sensor insertion hole 82 formed in the cylinder head and then into a sensor hole 81 formed in the flange portion 37 of the injection nozzle 5D.

[0033] In the injection device 3D according to the second modified example, it is also necessary to position the rotational position of the injection nozzle 5D when attaching the injection nozzle 5D to the heating cylinder 19. This is because it is necessary to align the sensor insertion hole 82 and the sensor hole 81 in order to provide the temperature sensor 80. The rotational position of the injection nozzle 5D can be aligned by the groove 43 of the injection nozzle 5D and the positioning jig 55 (see FIG. 5) already described.

[0034] Although the invention made by the present inventor has been specifically described above based on the embodiment, it goes without saying that the present invention is not limited to the embodiment already described, and various modifications are possible without departing from the gist of the invention. The above-described examples may be implemented in appropriate combination. [Explanation of symbols]

[0035] 1 Injection molding machine 2 Mold clamping device 3 Injection unit 4 Control unit 5 Injection nozzle 6 Shut-off nozzle 7 Bed 9 Fixed plate 10 Upper movable plate 11 Lower movable plate 12 Tie bar 14 toggle mechanism 15 turntable 17 Upper mold 18 Lower mold 19 Heating cylinder 20 Screw 22 Screw drive device 23 Lifting device 25 Heater 28 Mounting and fixing member 29 Needle valve 31 Fixing member 32 Bracket 34 Drive mechanism 36 Torso 37 Flange portion 38 Resin flow path 39 Injection port 41 Needle hole 43 Groove portion 45 Cylindrical portion 46 Fastening portion 47 Through hole 49 Male thread 51 Hole 55 Positioning jig 56 Base part 57 Pin 59 Bolt hole 61 Volts 63 Alignment pin 64 Pin hole 67 Extension fixing member 70 Flat surface 71 Guide member 74 Mounting member 75 Block 76 Volts 80 Temperature sensor 81 Sensor hole 82 Sensor insertion hole

Claims

1. A method for determining a rotational position of an injection nozzle attached to a tip of a heating cylinder by a predetermined attachment member with respect to the heating cylinder, the method comprising the steps of: the injection nozzle has a flange portion with an expanded diameter at a rear end portion, and when the mounting and fixing member is loosened with respect to the heating cylinder, the injection nozzle is allowed to rotate with respect to the heating cylinder, and when the mounting and fixing member is tightened, the flange portion is pressed against the tip end of the heating cylinder by the mounting and fixing member, and the injection nozzle is fixed in a state in which rotation is restricted, a notch extending in an axial direction is formed on an outer peripheral surface of a body portion of the injection nozzle, A method for positioning the rotational position of an injection nozzle, in which, when fixing the injection nozzle to the heating cylinder, a predetermined positioning member is provided in a state in which its relative movement with respect to the heating cylinder is restricted, the positioning member is slidably engaged with the cutout portion to restrict the rotation of the injection nozzle, and the mounting and fixing member is tightened to the heating cylinder.

2. 2. The method for positioning the rotational position of an injection nozzle according to claim 1, wherein said cutout portion is a groove portion extending in the axial direction in said body portion, and said positioning member is a pin having a tip end inserted into said groove portion.

3. 2. The method for positioning the rotational position of an injection nozzle according to claim 1, wherein the cutout portion comprises a pair of parallel flat surfaces formed at both diametrical ends of the body portion, and the positioning member is a pair of guide members that sandwich and contact the pair of flat surfaces.

4. the injection nozzle is a shut-off nozzle equipped with a needle valve and an actuator, a needle hole is formed in the body from the outer circumferential surface to an internal injection flow path, the needle valve is inserted into the needle hole, and the injection flow path is opened and closed when the needle valve is driven by the actuator, the notch is formed on the same side as the needle hole in the circumferential direction of the body portion, 3. The method for positioning the rotational position of an injection nozzle according to claim 1, further comprising the steps of: removing the needle valve from the injection nozzle; and fixing the positioning member to a member to which the actuator is attached when the injection nozzle is fixed to the heating cylinder.

5. the injection nozzle is a shut-off nozzle equipped with a needle valve and an actuator, a needle hole is formed in the body from the outer circumferential surface to an internal injection flow path, the needle valve is inserted into the needle hole, and the injection flow path is opened and closed when the needle valve is driven by the actuator, the notch is formed at a position shifted from the needle hole by a predetermined offset angle in the circumferential direction of the body portion, 3. The method for positioning the rotational position of an injection nozzle according to claim 1, wherein the positioning member is provided so as to be shifted from the actuator by the shift angle.

6. An injection nozzle is attached to the tip of a heating cylinder by a predetermined attachment and fixing member, the injection nozzle has a flange portion with an expanded diameter at a rear end portion, and when the mounting and fixing member is loosened with respect to the heating cylinder, the injection nozzle is allowed to rotate with respect to the heating cylinder, and when the mounting and fixing member is tightened, the flange portion is pressed against the tip end of the heating cylinder by the mounting and fixing member, and the injection nozzle is fixed in a state in which rotation is restricted, a notch extending in an axial direction is formed on an outer peripheral surface of a body of the injection nozzle, the injection nozzle includes a positioning jig that determines a rotational position of the injection nozzle relative to the heating cylinder; The positioning jig is temporarily attached to a fixed member fixed to the heating cylinder when the injection nozzle is fixed to the heating cylinder, and a positioning member provided on the positioning jig engages with the cutout portion to position the rotational position of the injection nozzle.

7. 7. The injection nozzle according to claim 6, wherein said cutout portion is a groove portion extending in the axial direction in said body portion, and said positioning member is a pin having a tip end inserted into said groove portion.

8. 7. The injection nozzle according to claim 6, wherein said cutout portion is composed of a pair of parallel flat surfaces formed at both diametrical ends of said body portion, and said positioning member is a pair of guide members sandwiching and contacting said pair of flat surfaces.

9. the injection nozzle is a shut-off nozzle equipped with a needle valve and an actuator, a needle hole is formed in the body from the outer circumferential surface to an internal injection flow path, the needle valve is inserted into the needle hole, and the injection flow path is opened and closed when the needle valve is driven by the actuator, the notch portion is formed on the same side as the needle hole in the circumferential direction of the body portion, 8. The injection nozzle according to claim 6, wherein the positioning jig is configured so that, when the injection nozzle is fixed to the heating cylinder, the needle valve is removed from the injection nozzle and a bracket to which the actuator is attached is attached as the fixing member.

10. the injection nozzle is a shut-off nozzle equipped with a needle valve and an actuator, a needle hole is formed in the body from the outer circumferential surface to an internal injection flow path, the needle valve is inserted into the needle hole, and the injection flow path is opened and closed when the needle valve is driven by the actuator, the notch portion is formed at a position shifted from the needle hole by a predetermined deviation angle in the circumferential direction of the body portion, 8. The injection nozzle according to claim 6 or 7, wherein when the injection nozzle is fixed to the heating cylinder, the positioning jig is configured to shift the bracket to which the actuator is attached by the deviation angle as the fixing member.

11. A heating cylinder; A screw contained in the heating cylinder; an injection nozzle attached to the tip of the heating cylinder by a predetermined attachment member; the injection nozzle has a flange portion with an expanded diameter at a rear end portion, and when the mounting and fixing member is loosened with respect to the heating cylinder, the injection nozzle is allowed to rotate with respect to the heating cylinder, and when the mounting and fixing member is tightened, the flange portion is pressed against the tip end of the heating cylinder by the mounting and fixing member, and the injection nozzle is fixed in a state in which rotation is restricted, a notch extending in an axial direction is formed on an outer peripheral surface of a body of the injection nozzle, the injection nozzle includes a positioning jig that determines a rotational position of the injection nozzle relative to the heating cylinder; The positioning jig is temporarily attached to a fixed member fixed to the heating cylinder when the injection nozzle is fixed to the heating cylinder, and a positioning member provided on the positioning jig engages with the cutout portion to position the rotational position of the injection nozzle.

12. An injection device; A mold clamping device, The injection device includes a heating cylinder and A screw contained in the heating cylinder; an injection nozzle attached to the tip of the heating cylinder by a predetermined attachment member; the injection nozzle has a flange portion with an expanded diameter at a rear end portion, and when the mounting and fixing member is loosened with respect to the heating cylinder, the injection nozzle is allowed to rotate with respect to the heating cylinder, and when the mounting and fixing member is tightened, the flange portion is pressed against the tip end of the heating cylinder by the mounting and fixing member, and the injection nozzle is fixed in a state in which rotation is restricted, a notch extending in an axial direction is formed on an outer peripheral surface of a body of the injection nozzle, the injection nozzle includes a positioning jig that determines a rotational position of the injection nozzle relative to the heating cylinder; An injection molding machine in which, when the injection nozzle is fixed to the heating cylinder, the positioning jig is temporarily attached to a fixed member fixed to the heating cylinder, and a positioning member provided on the positioning jig engages with the cutout portion to position the rotational position of the injection nozzle.

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