Spraying device

Abstract

Injection device (12) which performs a molding process by injecting molding compound into a mold from a nozzle element provided at a distal end of a cylinder (14), wherein the injection device (12) comprises: a piston (20) which is arranged in an inner bore (14a) of the cylinder (14) and in an inner bore (16a, 80a) of the nozzle element and is movable in a forward-backward direction along an axial direction; a feed bore (22) provided in the nozzle element so that the molding compound can be fed into the inner bore (16a, 80a) of the nozzle element; an annular seal (72) which is provided behind the feed bore (22) and is designed to prevent the molding compound fed in from the feed bore (22) from flowing rearward along the piston (20); and a sealing housing (24) designed to hold the seal (72), wherein the sealing housing (24) is tubular and has an outer diameter larger than the diameter of each of the inner bores (14a, 16a, 80a), wherein the sealing housing (24) is fixed by the cylinder (14) and the nozzle element attached to the cylinder (14), and comprises the following: a first inner surface (F1) which forms a first inner bore (24b) through which the piston (20) moves; and a second inner surface (F2) forming a second inner bore (24c) in which the seal (72) is held, wherein the second inner bore (24c) has a larger diameter than the first inner bore (24b) and is coaxial to the first inner bore (24b); and wherein an internal thread section (24d) having a larger diameter than the piston (20) is formed in at least a part of the first internal surface (F1).

Description

field of technology

[0001] The present invention relates to an injection device for injecting molding material. State of the art

[0002] An injection molding machine performs a molding process by injecting raw plastic into a mold. JP H06 – 86 912 U discloses an extruder. This extruder uses a sealing element to prevent the raw plastic from escaping. Further prior art is disclosed in JP 2017 - 170 502 A, DE 10 2019 107 235 A1 and JP S60 - 109 917 U. Summary of the invention

[0003] However, removing the sealing element from the extruder disclosed in JP H06-086912 U is not always easy. Consequently, performing maintenance tasks, such as inspecting and replacing the sealing element, was sometimes time-consuming. Furthermore, the sealing element was occasionally damaged during removal. Therefore, it is the function of the injection molding device to facilitate the removal of the sealing element.

[0004] The present invention aims to solve the aforementioned problem.

[0005] According to one aspect of the present invention, an injection device is provided which performs a molding operation by injecting molding compound into a mold from a nozzle element provided at a distal end of a cylinder, wherein the injection device comprises: a piston arranged in an inner bore of the cylinder and in an inner bore of the nozzle element and movable in a forward-backward direction along an axial direction; a feed bore provided in the nozzle element so that the molding compound can be fed into the inner bore of the nozzle element; an annular seal provided behind the feed bore and designed to prevent the molding compound fed from the feed bore from flowing rearward along the piston;and a sealing housing configured to hold the seal, wherein the sealing housing is tubular and has an outer diameter larger than the diameter of each of the inner bores. The sealing housing is fixed by the cylinder and the nozzle element attached to the cylinder, and comprises: a first inner surface forming a first inner bore through which the piston moves; and a second inner surface forming a second inner bore in which the seal is held, the second inner bore having a larger diameter than the first inner bore and being coaxial with the first inner bore. An internal threaded section having a larger diameter than the piston is formed in at least a portion of the first inner surface.

[0006] According to a further aspect of the present invention, an injection device is provided which performs a molding operation by injecting molding compound into a mold from a nozzle provided at a distal end of a cylinder, wherein the injection device comprises: a screw arranged in an inner bore of the cylinder and movable in a forward-backward direction along an axial direction; a feed bore provided in the cylinder so that the molding compound can be fed into the inner bore of the cylinder; an annular seal provided behind the feed bore and designed to prevent the molding compound fed from the feed bore from flowing backward along the screw;and a sealing housing configured to hold the seal, wherein the sealing housing is tubular and has an outer diameter larger than the diameter of the cylinder's inner bore. The sealing housing is fixed by the cylinder and comprises: a first inner surface forming a first inner bore through which the screw moves; and a second inner surface forming a second inner bore in which the seal is held, the second inner bore having a larger diameter than the first inner bore and being coaxial with the first inner bore. An internal threaded section having a larger diameter than the screw is formed in at least a portion of the first inner surface.

[0007] According to the present invention, it is possible to provide an injection device from which the seal can be easily removed. Brief description of the drawings Fig. Figure 1 is a view showing an injection molding machine according to a first embodiment; Fig. Figure 2 is an enlarged view showing part of a spraying device according to the first embodiment; Fig. Figure 3 is a view showing a state in which a seal and seal housing are separated from a nozzle adapter; Fig. Figure 4 is a view showing the injection molding machine according to a second embodiment; Fig. Figure 5 is a view showing the injection molding machine according to a third embodiment; Fig. 6 is a view showing the sealing housing according to a first modification; Fig. 7 is a view showing the sealing housing according to a second modification; Fig. Figure 8 is a view showing the sealing housing according to a third modification; Fig. 9A is a view showing the injection molding machine according to an example of a fourth modification; Fig. 9B is a view showing the injection molding machine according to the example of the fourth modification; Fig. 9C is a view showing the injection molding machine according to the example of the fourth modification; Fig. 10A is a view showing the injection molding machine according to another example of the fourth modification; Fig. Figure 10B is a view showing the injection molding machine according to the further example of the fourth modification; and Fig. 10C is a view showing the injection molding machine according to the further example of the fourth modification. Detailed description of the invention

[0008] Preferred embodiments of a spraying device according to the present invention are described in more detail below with reference to the accompanying drawings.

[0009] An injection molding machine comprises a machine base, a mold clamping device, and an injection unit. The mold clamping device and the injection unit are installed on the machine base so that they are opposite each other. The mold clamping device has a mold that can be opened and closed. The injection unit has a cylinder and a nozzle. The injection molding machine performs a molding cycle, which is controlled by a control unit. The molding cycle is a process in which a molding operation is carried out by injecting the molding compound into the mold from the nozzle located at the distal end of the cylinder. The molding cycle includes a metering operation and an injection operation. The injection molding machine according to the present embodiment is characterized by the injection unit. Therefore, the injection unit is described in detail, and the description of the other components is omitted. [First embodiment]

[0010] The injection device according to a first embodiment will now be described. Fig. Figure 1 is a view showing an injection molding machine 10 according to the first embodiment. Fig. Figure 1 mainly shows the configuration of an injection molding device 12, and the representation of the machine base and the mold clamping device is omitted.

[0011] The injection device 12 comprises a cylinder 14, a nozzle 18, and a piston 20. The nozzle 18 is attached to the distal end of the cylinder 14 via a nozzle adapter 16. The piston 20 is located inside the cylinder 14 and the nozzle adapter 16. The piston 20 is movable in the forward-backward direction and rotatable about the forward-backward direction (rotatable about the axis of the piston 20). The cylinder 14, the nozzle adapter 16, and the nozzle 18 function as a cylinder for injecting molding compound. The nozzle adapter 16 and the nozzle 18 also function as a nozzle element. An internal bore 14a is formed in the cylinder 14. The internal bore 14a allows the piston 20 to move in the forward-backward direction. Additionally, an internal bore 16a is formed in the nozzle adapter 16. The inner bore 16a allows the piston 20 to move in the forward-backward direction.For injecting the molding compound into the mold of the mold clamping device, the nozzle 18 has a nozzle opening 18a. The nozzle opening 18a is connected to the inner bore 16a of the nozzle adapter 16. The inner bore 16a of the nozzle adapter 16 is connected to the inner bore 14a of the cylinder 14. The inner bore 14a and the inner bore 16a preferably have the same inner diameter. A direction in which the piston 20 moves toward the mold (i.e., toward the nozzle 18) is referred to as the forward direction. A direction in which the piston 20 moves toward a side opposite the mold (i.e., toward a side opposite the nozzle 18) is referred to as the reverse direction.

[0012] An inlet bore 22 is formed in the nozzle adapter 16. The inlet bore 22 is a bore for feeding the liquid molding compound into the inner bore 16a of the nozzle adapter 16 in front of the piston 20. A sealing housing 24 is accommodated in the nozzle adapter 16 behind the inlet bore 22. The sealing housing 24 holds a seal 72. The seal 72 prevents the molding compound supplied from the inlet bore 22 from flowing backward (prevents backflow of the molding compound). The sealing housing 24 facilitates the removal of the seal 72 from the injection molding machine 10. The details are described below.

[0013] A temperature control device 26 is provided on the outer circumferential surfaces of the cylinder 14 and the nozzle adapter 16. The temperature control device 26 regulates the temperature of the molding compound in the nozzle adapter 16 and in the cylinder 14.

[0014] A bore 28 is provided at the proximal end of cylinder 14. The bore 28 communicates with the inner bore 14a. Accordingly, even if gas is generated from the molding compound or even if air is carried along in the molding compound, the gas or air can be discharged from the bore 28. As a result, it is possible to reduce the occurrence of injection molding defects due to silver streaks, air bubbles, or the like.

[0015] A molding compound feed device 30 of the injection molding machine 10 generates a filling pressure by using a drive force or the like, which is produced by a pneumatic, hydraulic, or electric motor. The molding compound feed device 30 conveys the molding compound with the aid of the filling pressure from the feed bore 22 to the front of the piston 20. Preferably, a check valve 32 should be provided in the feed bore 22. This serves to prevent the molding compound fed into the inner bore 16a from flowing backward and outward from the feed bore 22 (into the molding compound feed device 30).

[0016] The injection molding device 12 comprises a base 40, a linear guide 42, and a slide plate 44. The base 40 is mounted on the machine base so that it is movable in the forward and backward direction relative to the machine base. The linear guide 42 is attached to the base 40. The slide plate 44 is mounted on the linear guide 42 so that it is movable in the forward and backward direction relative to the base 40. The proximal end of the cylinder 14 is attached to the base 40 via a front plate 46. The slide plate 44 supports the proximal end of the piston 20 so that it is rotatable. A rotary drive disk 48 is provided at the proximal end of the piston 20. When the rotary drive disk 48 rotates, the piston 20 rotates in the axial direction of the piston 20 (of the cylinder 14) (in the forward-backward direction).

[0017] Furthermore, a ball screw drive 50 is screwed into the slide plate 44. A rear plate 52 is attached to the base 40. The rear plate 52 supports the ball screw drive 50 at its proximal end so that it can rotate. When the ball screw drive 50 rotates, the slide plate 44 moves in a forward-backward direction, guided by the linear guide 42. That is, the ball screw drive 50 and the slide plate 44 convert a rotary motion of the ball screw drive 50 into a linear motion. Along with the forward-backward movement of the slide plate 44, the piston 20 moves in a forward-backward direction with respect to the cylinder 14.

[0018] The injection molding machine 10 comprises, in addition to the molding compound feeding device 30, a servo motor 60, a servo motor 62, and a control unit 64. The servo motor 60 sets the piston 20 in a rotary motion. The servo motor 62 moves the piston 20 in a forward-reverse direction. The control unit 64 controls the servo motors 60 and 62. The rotary drive force of the servo motor 60 is transmitted to the rotary drive pulley 48 via a transmission mechanism (not shown) (an endless belt, a pulley, or the like). This causes the rotary drive pulley 48 to rotate, and the piston 20 also rotates. Furthermore, the rotary drive force of the servo motor 62 is transmitted to the ball screw drive 50 via a transmission mechanism (not shown) (an endless belt, a pulley, or the like).As a result, when the ball screw drive 50 rotates, the slide plate 44 and the piston 20 move in the forward-backward direction.

[0019] During the dosing process of the molding cycle, the control unit 64 controls the servo motor 62 to move the piston 20 backward, thereby dosing the molding compound. At this point, the molding compound feed device 30 feeds the molding compound from the feed bore 22, controlled by the control unit 64. During the dosing process, the molding compound flows from the feed bore 22 into a chamber 70 (dosing chamber). The chamber 70 is located in front of the piston 20 and is formed between the inner bore 16a of the nozzle adapter 16 and the piston 20. After completion of the dosing process, the control unit 64 brings the nozzle 18 into contact with the mold by moving the entire injection unit 12 forward. The control unit 64 then executes injection control.This means that the control unit 64 performs an injection control by moving the piston 20 forward to inject the metered molding compound towards the mold. The metered molding compound refers to the molding compound located in chamber 70. This injection control is carried out by controlling the servo motor 62. (Details of the sealing housing 24)

[0020] The sealing housing 24 is described in detail below. Fig. Figure 2 is an enlarged view showing part of the injection device 12 according to the first embodiment. Here, the area around the sealing housing 24 is shown in enlarged form. Fig. Figure 3 is a view showing a state in which the seal 72 and the sealing housing 24 are separated from the nozzle adapter 16.

[0021] As in Fig. 2 and Fig. As shown in Figure 3, the sealing housing 24 is fixed by the cylinder 14 and the nozzle adapter 16. Here, the sealing housing 24 is as shown in Fig. Figure 3 shows the nozzle adapter 16 being received in a receiving bore 16b (second receiving bore) so that it can be inserted and removed. The sealing housing 24 is also held in the receiving bore 16b by the front end region of the cylinder 14. The receiving bore 16b is formed in the rear end region of the nozzle adapter 16. The nozzle adapter 16 and the cylinder 14 are fastened to each other by screws or similar fasteners (not shown).

[0022] The seal 72 is annular and, as described above, prevents backflow of the molding compound. In particular, the seal 72 prevents the molding compound from flowing backward along the piston 20. That is, the seal 72 prevents the molding compound from flowing through a gap between an inner surface Fa of the inner bore 16a and an outer circumferential surface of the piston 20. The seal housing 24 is tubular. The seal housing 24 has an outer diameter that is larger than the inner diameter of the inner bore 14a of the cylinder 14 and the inner diameter of the inner bore 16a of the nozzle adapter 16.

[0023] As in Fig. As shown in Figure 2, the piston 20 moves through the sealing housing 24. An inner bore 24a of the sealing housing 24 has an inner bore 24b (first inner bore) and an inner bore 24c (second inner bore). The piston 20 moves through the inner bore 24b. The inner bore 24b is formed by an inner surface F1 (first inner surface). Note that the inner diameter of the inner bore 24b can be equal to the inner diameter of the inner bore 16a or the inner diameter of the inner bore 14a. The inner bore 24c is located at the end region of the sealing housing 24 (here, at the front end region of the sealing housing 24). The seal 72 is held in the inner bore 24c. The inner bore 24c is coaxial with the inner bore 24b. The internal bore 24c has a larger internal diameter than the internal bore 24b. The internal bore 24c is formed by an internal surface F2 (second internal surface).An internal thread section 24d is formed in at least part of the inner surface F1 of the inner bore 24b (here, the rear end region of the inner bore 24b). The internal thread section 24d has an inner diameter that is larger than the outer diameter of the piston 20. This allows the seal 72 to be easily removed from the injection device 12, as described below.

[0024] An O-ring 74 can be provided on the outer circumferential surface of the sealing housing 24. The O-ring 74 prevents the molding compound from flowing backward through a gap between an inner surface Fb of the receiving bore 16b of the nozzle adapter 16 and the outer circumferential surface of the sealing housing 24. Furthermore, an annular groove 24e is formed in the outer circumferential surface of the sealing housing 24. The annular groove 24e retains the O-ring 74. Because the sealing housing 24 has the annular groove 24e for retaining the O-ring 74, the O-ring 74 can be removed from the injection molding device 12 together with the sealing housing 24.

[0025] It should be noted that multiple O-rings 74 can be used. That is, by providing multiple O-rings 74 on the outer circumferential surface of the sealing housing 24, backflow of the molding compound can be prevented more effectively. In this case, the multiple O-rings 74 can be retained in the multiple annular grooves 24e by forming multiple annular grooves 24e in the outer circumferential surface of the sealing housing 24.

[0026] The removal of the seal 72 from the injection molding device 12 is now described. For example, when the seal 72 is being serviced, a removal screw (external thread screw) is screwed into the internal thread section 24d of the seal housing 24. This allows the removal screw to be used as a handle for the seal housing 24. First, for example, the rear end of the seal housing 24 is exposed from the rear end of the nozzle adapter 16 by separating the cylinder 14 and the nozzle adapter 16. Then, the removal screw is screwed into the internal thread section 24d of the seal housing 24, and the removal screw is pulled. In this way, the seal 72, together with the seal housing 24, can be removed from the nozzle adapter 16. This means that the seal 72 can be easily removed from the injection molding device 12. This reduces the time required for removing the seal 72.Furthermore, it can be prevented that the seal 72 is damaged by excessive stress applied to the seal 72 during removal. [Second embodiment]

[0027] The injection device 12 according to a second embodiment will now be described. Fig. Figure 4 shows the injection molding machine 10 according to the second embodiment. For clarity, the area around the sealing housing 24 is shown enlarged. It should be noted that components corresponding to those of the first embodiment are designated with the same reference numerals, and a description of them is omitted.

[0028] The injection device 12 according to the second embodiment has a nozzle 80 instead of the nozzle adapter 16 and the nozzle 18 of the first embodiment. The nozzle 80 functions as a nozzle element. The nozzle 80 is located directly at the distal end of the cylinder 14. The nozzle 80 and the cylinder 14 are fastened to one another by screws or the like (not shown). The cylinder 14 and the nozzle 80 function as a cylinder for injecting the molding compound. The injection device 12 shapes the molding compound by injecting it from a nozzle opening 80c of the cylinder (the nozzle 80) into a mold (not shown). The piston 20 is located inside the cylinder (specifically within the inner bore 14a and an inner bore 80a). The piston 20 is movable in the axial direction in a forward-backward motion. The feed bore 22 is provided in the nozzle 80.The feed bore 22 is a bore for feeding the molding compound into the inner bore 80a of the nozzle 80. A receiving bore 80b (first receiving bore), in which the sealing housing 24 is received, is formed in the rear end region of the nozzle 80. The sealing housing 24 can be inserted into and removed from the receiving bore 80b, which is formed in the rear end region of the nozzle 80.

[0029] The seal 72 can be removed from the injection device 12 as follows. First, for example, the rear end of the seal housing 24 is exposed from the rear end of the nozzle 80 by separating the cylinder 14 and the nozzle 80. Then, the removal screw is screwed into the internal threaded section 24d of the seal housing 24, and the removal screw is pulled. In this way, the seal 72, together with the seal housing 24, can be removed from the nozzle 80.

[0030] Since the second embodiment, with the exception of the features mentioned above, essentially corresponds to the first embodiment, a detailed description of it is omitted. [Third embodiment]

[0031] The injection device 12 according to a third embodiment will now be described. Fig. Figure 5 is a view showing the injection molding machine 10 according to the third embodiment. It should be noted that components corresponding to those of the second embodiment are designated with the same reference numerals, and a description of them is omitted.

[0032] The injection device 12 according to the third embodiment has a screw 82 instead of the piston 20 of the second embodiment, and does not have the feed bore 22 and the molding compound feeding device 30. The screw 82 is provided inside the inner bore 14a and the inner bore 80a, is movable axially in the forward-reverse direction, and is rotatable about its axis. A configuration corresponding to the first embodiment can be used by using the nozzle adapter 16 and the nozzle 18 instead of the nozzle 80.

[0033] Here, the bore 28 provided in the cylinder 14 is used as a feed bore. That is, the molding compound is fed from the bore 28 into the inner bore 14a of the cylinder 14. For example, the molding compound (e.g., a resin material in granular form) is fed into the inner bore 14a via the bore 28 using a funnel (not shown). During the metering process of the molding cycle, the control unit 64 controls the servo motor 60 and the servo motor 62 so that the screw 82 rotates and moves backward, thereby metering the molding compound. During the metering process, the screw 82 moves backward while rotating, thus feeding the molding compound inside the inner bore 14a of the inner bore 80a (the chamber 70) of the nozzle 80 located in front of it, along the groove of the screw 82.After the dosing process is complete, the control unit 64 brings the nozzle 80 into contact with the mold by moving the entire injection unit 12 forward. The control unit 64 then executes the injection control. That is, the control unit 64 controls the servo motor 62 to move the screw 82 forward, thereby causing the molding compound to be injected into chamber 70 from the front end of the nozzle opening 80c towards the mold.

[0034] The sealing housing 24 is attached to the cylinder 14 located behind the bore 28 (feed bore). The cylinder 14 is axially divisible into a first element 142 at the front and a second element 144 at the rear. The sealing housing 24 is received in a receiving bore 14b (fourth receiving bore) formed in the rear end region of the first element 142, allowing it to be inserted and removed. The sealing housing 24 is also held in the receiving bore 14b by the front end region of the second element 144. The first element 142 and the second element 144 are fastened together by screws or similar fasteners (not shown).

[0035] The seal 72 can be removed from the injection molding device 12 as follows. First, for example, the rear end of the seal housing 24 is exposed from the rear end of the first element 142 by separating the first element 142 and the second element 144. Then, the removal screw is screwed into the internal threaded section 24d of the seal housing 24, and the removal screw is pulled. In this way, the seal 72, together with the seal housing 24, can be removed from the first element 142.

[0036] Since the third embodiment, with the exception of the features mentioned above, essentially corresponds to the first and second embodiments, a detailed description of the same is omitted. (Modification 1)

[0037] The sealing housing 24 is described below according to a first modification. Fig. Figure 6 is a view showing the sealing housing 24 according to the first modification. As in Fig. As shown in Figure 6, in the first modification, the internal thread section 24d is formed on the entire inner surface F1 of the inner bore 24b (first inner bore). This allows the sealing housing 24 and the seal 72 to be easily separated, even if the seal 72 is adhered to the sealing housing 24. That is, the removal screw is screwed into the internal thread section 24d of the sealing housing 24, and then the removal screw is turned. Consequently, by applying pressure to the tip of the removal screw so that it reaches the interior of the inner bore 24c (the interior of the second inner bore), the seal 72 can be pushed out of the sealing housing 24.

[0038] Since the sealing housing 24 according to the first modification, with the exception of the features mentioned above, corresponds to the sealing housing 24 according to the first to third embodiments, a detailed description of the latter is omitted. That is to say, the sealing housing 24 according to the first modification can be used in any of the first to third embodiments. (Modification 2)

[0039] The sealing housing 24 will now be described according to a second modification. Fig. Figure 7 is a view showing the sealing housing 24 according to the second modification and represents a state in which the seal 72 and the sealing housing 24 are separated from the nozzle adapter 16.

[0040] As in Fig. As shown in Figure 7, the sealing housing 24 holds a plurality of seals 72 (here a front and a rear seal, i.e., two seals 72). In addition to the internal bore 24b (first internal bore) and the internal bore 24c (second internal bore) located on the front side, the sealing housing 24 has an internal bore 24c (third internal bore) located on the rear side. The rear seal 72 is held in the internal bore 24c on the rear side. The internal bore 24c on the rear side has a larger internal diameter than the internal bore 24b. The internal bore 24c on the rear side is coaxial with the internal bore 24b and the internal bore 24c on the front side. The majority of seals 72 are held in place by the fact that the majority of internal bores 24c are provided to hold the seals 72 in them, thereby improving the backflow prevention function.The sealing housing 24 holds two seals 72 here, but can also hold three or more seals 72.

[0041] In the second modification as well, the seal 72 can be removed together with the seal housing 24 by screwing the removal screw into the internal threaded section 24d of the seal housing 24. Note that the rear seal 72 can be removed before the removal screw is screwed in.

[0042] Since the sealing housing 24 according to the second modification corresponds to the sealing housing 24 according to the first to third embodiments, with the exception of the features mentioned above, a detailed description of the latter is omitted. That is to say, the sealing housing 24 according to the second modification can be used in any of the first to third embodiments. (Modification 3)

[0043] The sealing housing 24 will now be described according to a third modification. Fig. Figure 8 is a view showing the sealing housing 24 according to the third modification and represents a state in which the seal 72 and the sealing housing 24 are separated from the nozzle adapter 16.

[0044] As in Fig. As shown in Figure 8, in the third modification, the O-ring 74 is provided at the end face of the sealing housing 24. Furthermore, the annular groove 24e is formed to retain the O-ring 74 in the end face of the sealing housing 24. In this way, the O-ring 74 can be held at the end face of the sealing housing 24. The O-ring 74 at the end face of the sealing housing 24 helps to prevent backflow and can be removed together with the sealing housing 24.

[0045] Here, an O-ring 74 is provided at the end face of the sealing housing 24; however, another O-ring 74 may also be provided. For example, multiple O-rings 74 may be provided at the end face of the sealing housing 24. Furthermore, the O-rings 74 may be provided at both the end face and the outer circumferential surface of the sealing housing 24. This allows for more effective prevention of backflow of the molding compound. In this case, the multiple O-rings 74 can be retained in the multiple annular grooves 24e by forming a multiple of annular grooves 24e in the end face (and the outer circumferential surface) of the sealing housing 24.

[0046] Since the sealing housing 24 according to the third modification corresponds to the sealing housing 24 according to the first to third embodiments, with the exception of the features mentioned above, a detailed description of the latter is omitted. That is to say, the sealing housing 24 according to the third modification can be used in any of the first to third embodiments. (Modification 4)

[0047] The following describes the injection device 12 according to a fourth modification. Fig. Figures 9A to 9C are views showing injection molding machine 10 according to an example of the fourth modification. Fig. 10A to 10C are views showing the injection molding machine 10 according to another example of the fourth modification.

[0048] The Fig. 9A and Fig. Figure 10A shows a state in which the sealing housing 24 is separated from the nozzle adapter 16 in the injection device 12, according to the first embodiment. In the Fig. 9A and Fig. 10A the sealing housing 24 is fixed by the cylinder 14 and the nozzle adapter 16.

[0049] In the Fig. In embodiment 9A, instead of the receiving bore 16b in the first embodiment, the receiving bore 14b (third receiving bore) is formed in the front end region of the cylinder 14. The sealing housing 24 is received in the receiving bore 14b, which is formed in the front end region of the cylinder 14, in such a way that it can be inserted and removed. The sealing housing 24 is held in the receiving bore 14b by the rear end region of the nozzle adapter 16.

[0050] In the Fig. The receiving bore 16b (second receiving bore) is formed in the rear end region of the nozzle adapter 16, and the receiving bore 14b (third receiving bore) is formed in the front end region of the cylinder 14. The sealing housing 24 is received and held inside the receiving bore 16b and the receiving bore 14b.

[0051] In the Fig. In 10A, the length of the receiving bore 16b is greater than the length of the receiving bore 14b. This is because the sealing housing 24 is intended to be held by the nozzle adapter 16 when the nozzle adapter 16 and the cylinder 14 are separated. It should be noted that the sealing housing 24 can also be held by the nozzle adapter 16 using a different method. Furthermore, the sealing housing 24 can be held by the cylinder 14. Additionally, the sealing housing 24 can be held by any of the nozzle adapter 16 or the sealing housing 24.

[0052] The Fig. 9B and Fig. Figure 10B shows a state in which the sealing housing 24 is separated from the nozzle 80 in the injection device 12, according to the second embodiment. In the Fig. 9B and Fig. 10B the sealing housing 24 is fixed by the cylinder 14 and the nozzle 80.

[0053] In Fig. 9B is the receiving bore 14b (third receiving bore) formed in the front end region of the cylinder 14. The sealing housing 24 is received in the receiving bore 14b. Furthermore, in the Fig. The receiving bore 80b (first receiving bore) is formed in the rear end region of the nozzle 80 and the receiving bore 14b (third receiving bore) is formed in the front end region of the cylinder 14. The sealing housing 24 is received in the receiving bore 80b and in the receiving bore 14b.

[0054] In the Fig. In 10B, the length of the receiving bore 80b is greater than the length of the receiving bore 14b. This is because the sealing housing 24 is intended to be held by the nozzle 80 when the nozzle 80 and the cylinder 14 are separated. However, the sealing housing 24 can also be held by the cylinder 14. The sealing housing 24 can be held by either the nozzle 80 or the cylinder 14.

[0055] The Fig. 9C and Fig. Figure 10C shows a state in which the sealing housing 24 is separated from the cylinder 14 (the first element 142 and the second element 144) in the injection device 12, according to the third embodiment. In the Fig. 9C and Fig. 10C the sealing housing 24 is fixed by the cylinder 14 (the first element 142 and the second element 144).

[0056] In the Fig. 9C, the receiving bore 14b (fifth receiving bore) is formed in the front end region of the second element 144, and the sealing housing 24 is received in the receiving bore 14b. Furthermore, in the Fig. 10C two receiving bores 14b (fourth receiving bore and fifth receiving bore) are formed in the rear end region of the first element 142 and in the front end region of the second element 144, and the sealing housing 24 is received in the two receiving bores 14b.

[0057] In the Fig.In 10C, the length of the receiving bore 14b of the first element 142 is greater than the length of the receiving bore 14b of the second element 144. This is because the sealing housing 24 is intended to be held by the first element 142 when the first element 142 and the second element 144 are separated. However, the sealing housing 24 can also be held by the second element 144. The sealing housing 24 can be held by either the first element 142 or the second element 144.

[0058] Since the fourth embodiment corresponds to the first embodiment, the second embodiment and the third embodiment except for the features mentioned above, a detailed description of it is omitted. (Modification 5)

[0059] The following describes the injection device 12 according to a fifth modification. The fifth modification is a suitable combination of the first through fourth modifications. For example, the first and second modifications can be combined. In this case, the sealing housing 24 holds the majority of seals 72, and the internal thread section 24d is formed on the entire inner surface F1 of the inner bore 24b (first inner bore). [Modified embodiment]

[0060] The present invention is not limited to the embodiments described above, and various configurations can be used therein without deviating from the essence and core idea of ​​the present invention. [Invention emerging from the embodiments]

[0061] The present invention, which results from the embodiments and modifications described above, is described below. [1] The injection device (12) according to the present invention is an injection device which performs a molding operation by injecting the molding compound into the mold from the nozzle element ([the nozzle 80], [the nozzle adapter 16, the nozzle 18]) provided at the distal end of the cylinder (14), wherein the injection device comprises: the piston (20) which is arranged in the inner bore (14a) of the cylinder and in the inner bore (80a, 16a) of the nozzle element and is movable in the forward-backward direction along the axial direction; the feed bore (22) which is provided in the nozzle element so that the molding compound can be fed into the inner bore of the nozzle element; the annular seal (72) which is provided behind the feed bore and is designed to prevent the molding compound fed in from the feed bore from flowing backward along the piston;and the sealing housing (24), which is designed to hold the seal, wherein the sealing housing is tubular and has an outer diameter larger than the diameter of each of the inner bores. The sealing housing is fixed by the cylinder and the nozzle element attached to the cylinder, and has the following: the first inner surface (the inner surface F1), which forms the first inner bore (inner bore 24b) through which the piston moves;and the second inner surface (the inner surface F2), which forms the second inner bore (inner surface 24c) in which the seal is held, the second inner bore having a larger diameter than the first inner bore and being coaxial with the first inner bore. The internal threaded section (24d), which has a larger diameter than the piston, is formed in at least part of the first inner surface. According to this feature, the cylinder and the nozzle are separated from each other, the removal screw is screwed into the internal threaded section of the seal housing, and the seal can be easily removed together with the seal housing using the removal screw. [2] The nozzle element includes the nozzle (80), and the first receiving bore (the receiving bore 80b), in which the sealing housing is received, is formed in the rear end region of the nozzle such that the sealing housing can be inserted into and removed from the rear end region of the nozzle. According to this feature, the seal together with the sealing housing can be easily removed from the rear end region of the nozzle. [3] The nozzle element comprises the nozzle adapter (16) provided at the distal end of the cylinder and the nozzle (18) provided at the distal end of the nozzle adapter. The piston is arranged in the inner bore (14a) of the cylinder and in the inner bore (16a) of the nozzle adapter, and the feed bore is provided in the nozzle adapter so that the molding compound can be fed into the inner bore of the nozzle adapter. The seal housing is fixed by the cylinder and the nozzle adapter. According to this feature, the cylinder and the nozzle are separate from each other, the removal screw is screwed into the internal threaded section of the seal housing, and the seal can be easily removed together with the seal housing using the removal screw. [4] The second receiving bore (receiving bore 16b), in which the sealing housing is received, is designed in the rear end region of the nozzle adapter such that the sealing housing can be inserted into and removed from the rear end region of the nozzle adapter. According to this feature, the seal, together with the sealing housing, can be easily removed from the rear end region of the nozzle adapter. [5] The third receiving bore (receiving bore 14b), in which the seal housing is received, is designed in the front end region of the cylinder such that the seal housing can be inserted into and removed from the front end region of the cylinder. According to this feature, the seal together with the seal housing can be easily removed from the front end region of the cylinder. [6] The injection device according to the present invention is an injection device which performs a molding operation by injecting the molding compound into the mold from the nozzle (80) provided at the distal end of the cylinder, wherein the injection device comprises: the screw (82) which is arranged in the inner bore of the cylinder and is movable in the forward-backward direction along the axial direction; the feed bore (bore 28) which is provided in the cylinder so that the molding compound can be fed into the inner bore of the cylinder; the annular seal which is provided behind the feed bore and is designed in such a way as to prevent the molding compound fed from the feed bore from flowing backward along the screw;and the sealing housing designed to hold the seal, wherein the sealing housing is tubular and has an outer diameter larger than the diameter of the inner bore of the cylinder. The sealing housing is fixed by the cylinder and has the following: the first inner surface forming the first inner bore through which the screw moves;and the second inner surface, which forms the second inner bore in which the seal is held, wherein the second inner bore has a larger diameter than the first inner bore and is coaxial with the first inner bore. The internal threaded section, which has a larger diameter than the screw, is formed in at least a portion of the first inner surface. According to this feature, the removal screw is screwed into the internal threaded section of the seal housing, and the seal can be easily removed together with the seal housing using the removal screw. [7] The cylinder is axially divisible into the first element (142) at the front and the second element (144) at the rear, and the fourth receiving bore (receiving bore 14b), in which the seal housing is received, is formed in the rear end region of the first element such that the seal housing can be inserted into and removed from the rear end region of the first element. According to this feature, the seal, together with the seal housing, can be easily removed from the rear end region of the first element of the cylinder. [8] The cylinder is axially divisible into the first element at the front and the second element at the rear, and the fifth receiving bore (receiving bore 14b), in which the seal housing is received, is formed in the front end region of the second element such that the seal housing can be inserted into and removed from the front end region of the second element. According to this feature, the seal, together with the seal housing, can be easily removed from the front end region of the second element of the cylinder. [9] The injection device includes the O-ring (74) which is configured to prevent the molding compound from flowing backward from an area between the outer circumferential surface of the sealing housing and the inner surface (Fb) of any of the first receiving bore, the second receiving bore, the third receiving bore, the fourth receiving bore, or the fifth receiving bore (14b, 16b, 80b), wherein the annular groove (24e) configured to retain the O-ring is formed in the outer circumferential surface or in the end face of the sealing housing. According to this feature, leakage of the molding compound from an area between the receiving bore and the outer circumferential surface of the sealing housing can be prevented by using the O-ring held by the sealing housing.

[10] The internal thread section is formed over the entire surface of the first internal bore. According to this feature, the seal held in the second internal bore of the sealing housing can be pushed out of the sealing housing by screwing the removal screw into the internal thread section of the sealing housing.

[11] The injection molding device has a second tubular seal (the seal 72) located behind the feed bore and designed to prevent the molding compound fed in from the feed bore from flowing backward along the piston or screw. The seal housing has a third internal bore (the internal bore 24c) in which the second seal is held, the third internal bore having a larger diameter than the first internal bore and being coaxial with the first and second internal bores. Reference symbol list 10 injection molding machines 12 Spray device 14 cylinders 14a Inner bore of the cylinder 14b Receipt hole (third, fourth or fifth receipt hole) 142 First element of the cylinder 144 Second element of the cylinder 16 nozzle adapters 16a Inner bore of the nozzle adapter 16b Mounting bore of the nozzle adapter (second mounting bore) 18 nozzle 18a Nozzle opening 20 pistons 22 Feed-in borehole 24 sealing housings 24a Inner bore of the sealing housing 24b First inner bore of the sealing housing 24c Second or third inner bore of the sealing housing 24d internal thread section 24e Ring groove 26 Temperature control device 28 Borehole (feed bore in the third embodiment) 30 Molding compound feeding device 32 Check valve 40 sockets 42 Linear guide 44 sliding plate 46 Front panel 48 Rotary drive pulley 50 ball screw drive 52 Rear plate 60 Servomotor (for rotary movement of the piston) 62 Servomotor (for forward-backward movement of the piston) 64 Control unit Room 70 (dosing chamber) 72 Seal 74 O-ring 80 Nozzle (in the second and third embodiments) 80a Inner bore of the nozzle 80b Nozzle receiving bore (first receiving bore) 80° nozzle opening 82 snail F1 First inner surface of the sealing housing F2 Second inner surface of the sealing housing Fa Inner surface of the inner bore 16a Fb Inner surface of the receiving bore 16b

Claims

[1] Injection device (12) which performs a molding process by injecting molding compound into a mold from a nozzle element provided at a distal end of a cylinder (14), wherein the injection device (12) comprises: a piston (20) which is arranged in an inner bore (14a) of the cylinder (14) and in an inner bore (16a, 80a) of the nozzle element and is movable in a forward-backward direction along an axial direction; a feed bore (22) provided in the nozzle element so that the molding compound can be fed into the inner bore (16a, 80a) of the nozzle element; an annular seal (72) which is provided behind the feed bore (22) and is designed to prevent the molding compound fed in from the feed bore (22) from flowing rearward along the piston (20); and a sealing housing (24) designed to hold the seal (72), wherein the sealing housing (24) is tubular and has an outer diameter larger than the diameter of each of the inner bores (14a, 16a, 80a), wherein the sealing housing (24) is fixed by the cylinder (14) and the nozzle element attached to the cylinder (14), and comprises the following: a first inner surface (F1) which forms a first inner bore (24b) through which the piston (20) moves; and a second inner surface (F2) forming a second inner bore (24c) in which the seal (72) is held, wherein the second inner bore (24c) has a larger diameter than the first inner bore (24b) and is coaxial to the first inner bore (24b); and wherein an internal thread section (24d) having a larger diameter than the piston (20) is formed in at least a part of the first internal surface (F1). [2] Spray device (12) according to claim 1, wherein the nozzle element has a nozzle (80), and a first receiving bore (80b), in which the sealing housing (24) is received, is formed in a rear end region of the nozzle (80) such that the sealing housing (24) can be inserted into and removed from the rear end region of the nozzle (80). [3] Spray device (12) according to claim 1, wherein the nozzle element has a nozzle adapter (16) provided at the distal end of the cylinder and a nozzle (18) provided at the distal end of the nozzle adapter (16), the piston (20) is arranged in the inner bore (14a) of the cylinder (14) and in the inner bore (16a) of the nozzle adapter (16), the feed bore (22) is provided in the nozzle adapter (16) so that the molding compound can be fed into the inner bore (16a) of the nozzle adapter (16), and the sealing housing (24) is fixed by the cylinder (14) and the nozzle adapter (16). [4] Spray device (12) according to claim 3, wherein a second receiving bore (16b) in which the sealing housing (24) is received is formed in a rear end region of the nozzle adapter (16) such that the sealing housing (24) can be inserted into and removed from the rear end region of the nozzle adapter (16). [5] Injection device (12) according to any one of the preceding claims 1 to 4, wherein a third receiving bore (14b) in which the sealing housing (24) is received is formed in a front end region of the cylinder (14) such that the sealing housing (24) can be inserted into and removed from the front end region of the cylinder (14). [6] Injection device (12) which performs a molding process by injecting molding compound into a mold from a nozzle (80) provided at a distal end of a cylinder (14), wherein the injection device (12) comprises: a screw (82) which is arranged in an inner bore (80a) of the cylinder (14) and is movable in a forward-backward direction along an axial direction; a feed bore (28) provided in the cylinder (14) so ​​that the molding compound can be fed into the inner bore (80a) of the cylinder (14); an annular seal (72) which is provided behind the feed bore (28) and is designed to prevent the molding compound fed in from the feed bore (28) from flowing backwards along the screw (82); and a sealing housing (24) designed to hold the seal (72), wherein the sealing housing (24) is tubular and has an outer diameter that is larger than the diameter of the inner bore (80a) of the cylinder (14), wherein the sealing housing (24) is fixed by the cylinder (14) and has the following features: a first inner surface (F1) which forms a first inner bore (24b) through which the screw (82) moves; and a second inner surface (F2) forming a second inner bore (24c) in which the seal (72) is held, wherein the second inner bore (24c) has a larger diameter than the first inner bore (24b) and is coaxial to the first inner bore (24b); and wherein an internal thread section (24d) having a larger diameter than the screw (82) is formed in at least a part of the first internal surface (F1). [7] Spray device (12) according to claim 6, wherein the cylinder (14) is divisible in the axial direction into a first element (142) at a front side and a second element (144) at a rear side, and a fourth receiving bore (14b), in which the sealing housing (24) is received, is formed in a rear end region of the first element (142) such that the sealing housing (24) can be inserted into and removed from the rear end region of the first element (142). [8] Spray device (12) according to claim 6 or 7, wherein the cylinder (14) is divisible in the axial direction into a first element (142) at a front side and a second element (144) at a rear side, and a fifth receiving bore (14b), in which the sealing housing (24) is received, is formed in a front end region of the second element (144) such that the sealing housing (24) can be inserted into and removed from the front end region of the second element (144). [9] Spray device (12) according to one of claims 2, 4, 5, 7 and 8, further comprising: an O-ring (74) designed to prevent the molding compound from flowing backwards from an area between an outer circumferential surface of the sealing housing (24) and an inner surface (Fb) of any one of the first receiving bore (80b), the second receiving bore (16b), the third receiving bore (14b), the fourth receiving bore (14b), or the fifth receiving bore (14b), wherein a ring groove (24e) designed to hold the O-ring (74) is formed in the outer circumferential surface or in an end surface of the sealing housing (24). [10] Injection device (12) according to one of claims 1 to 9, wherein the internal thread section (24d) is formed on an entire surface of the first internal bore (24b). [11] Spray device (12) according to any one of claims 1 to 10, wherein the injection device (12) has a second tubular seal (72) which is provided behind the feed bore (22) and is designed to prevent the molding compound fed in from the feed bore (22) from flowing backwards along the piston (20) or the screw (82), and the sealing housing (24) has a third internal bore (24c) in which the second seal (72) is held, wherein the third internal bore (24c) has a larger diameter than the first internal bore (24b) and is coaxial to the first internal bore (24b) and the second internal bore (24c).

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