Heating housing and resin molding machine

Abstract

To provide a housing that allows easy replacement of a heater in a resin molding machine.SOLUTION: A cylinder barrel (105) as a heating housing includes: a hollow part inside an inner peripheral surface; a solid part surrounding the hollow part; a cylindrical barrel body (105A) with an axial direction (AD) and a circumferential direction (CD); and one or more heaters (109) built into the solid part and including at least a part or all of a straight part. The heater (109) is provided with the straight part along a direction intersecting the axial direction (AD).SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a housing capable of heating a resin in a molding machine for resin materials such as an injection molding machine and an extrusion molding machine.

Background Art

[0002] In an injection molding machine, for example, there is one that includes a cylinder surrounding a plasticizing screw for injection and melting of a resin, and a cylinder barrel surrounding the cylinder. In addition to both the cylinder and the cylinder barrel being cylindrical members (housings), a heater as a heating means such as a cartridge heater and a sheathed heater is provided to plasticize the resin and maintain the temperature of the plasticized resin. In an extrusion molding machine as well, a housing provided with a heater is used.

[0003] Patent Document 1 proposes incorporating a heater in a cylinder barrel as a housing. That is, in Patent Document 1, a plurality of heater chambers each having a void for accommodating a heater in a solid portion of the cylinder barrel are provided along the axial direction of the cylinder barrel. The plurality of heater chambers are drilled at equal intervals in the circumferential direction of the cylinder barrel, and a rod-shaped heater is incorporated in each heater chamber.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Heaters may need to be replaced due to wear, malfunction, or other reasons. If the heater chamber is located axially, the old heater to be replaced is removed axially, and the new heater is inserted axially. However, for example, the base of the cylinder needs to be firmly fixed to withstand the injection force. Also, since the drive unit that rotates the plasticizing screw is located close to the rear of the cylinder base, the space between the cylinder base and the drive unit is narrow. Therefore, when a heater needs to be replaced, the replacement work must be carried out in a narrow space, making the work very inefficient.

[0006] Therefore, the present invention aims to provide a housing that facilitates the replacement of heaters in a resin molding machine. [Means for solving the problem]

[0007] The heating housing of the present invention comprises a housing body and one or more heaters. The housing body comprises a hollow section and a solid section surrounding the hollow section, and has a cylindrical shape with axial and circumferential directions. The heater is housed within the solid portion and includes at least part or all of a straight portion. This heater is positioned along a direction in which the straight portion intersects the axial direction.

[0008] Preferably, the multiple heaters are arranged at different axial positions at equal or unequal intervals.

[0009] Preferably, the multiple heaters are arranged along the circumferential direction and in different phases around the central axis.

[0010] Preferably, each of the multiple heaters is positioned at an equal distance from the hollow section.

[0011] Preferably, multiple heaters are provided at the same axial position as a group of heaters with different phases in the circumferential direction. The multiple heater groups are preferably located at different positions in the axial direction. Each group of heaters, positioned at different locations in the axial direction, preferably has a different heating temperature.

[0012] The housing body preferably includes a heater chamber consisting of one or more straight voids formed in the solid portion and intersecting the axial direction of the housing body. The straight portion of the heater is housed in the heater chamber.

[0013] The present invention provides a resin molding machine comprising a screw for plasticizing a resin and one of the above-described heating housings surrounding the screw. [Effects of the Invention]

[0014] According to the housing of the present invention, the heater is installed in a direction intersecting, for example, perpendicular to, the axial direction of the housing. To replace the heater in this housing, the previously used heater is removed from the heater chamber in a direction intersecting the axial direction of the housing and toward the periphery of the housing, and the new heater is inserted into the heater chamber in the opposite direction to the removal. Since a large amount of empty space can be secured around the housing, the heater replacement work is easy with the housing of the present invention. [Brief explanation of the drawing]

[0015] [Figure 1] This is a partial cross-sectional view showing the injection molding machine according to the embodiment from the side. [Figure 2] This is a partial cross-sectional view showing an injection molding machine according to an embodiment, viewed from a planar direction. [Figure 3] This diagram shows an example where the heater (heater chamber) of a cylinder barrel intersects with the axial direction AD. [Figure 4] This figure shows an example in which multiple heaters (heater chambers) are arranged along the axial direction AD of the cylinder barrel. [Figure 5] This figure shows an example in which multiple heaters (heater chambers) are arranged along the circumferential direction CD of the cylinder barrel. [Figure 6]Front view showing the cylinder barrel shown in FIGS. 1 and 2, (a) without a heater, and (b) with a heater provided. [Figure 7] (a) is a view seen from the direction of VIIa in FIG. 6, and (b) is a view seen from the direction of VIIb in FIG. 6. [Figure 8] Diagram showing the operation of an injection molding machine according to an embodiment, where (a) shows the process of preparing for plasticization and metering, and (b) shows the process of plasticization and metering. [Figure 9] Following FIG. 8, it is a diagram showing the operation of an injection molding machine according to an embodiment, where (a) shows the preparation process for injection, and (b) shows the injection process.

Mode for Carrying Out the Invention

[0016] Hereinafter, an injection molding machine according to an embodiment will be described with reference to the accompanying drawings. The injection molding machine 1 can perform injection molding of a resin material by being combined with a mold clamping device (not shown). The injection molding machine 1 can suppress a decrease in the processing accuracy of the heater chamber by adopting an arrangement of a plurality of heaters 109 with characteristics in the cylindrical cylinder barrel 105. Hereinafter, the overall configuration of the injection molding machine 1, the arrangement of the heaters 109 in the cylinder barrel 105, and the effects exhibited by the injection molding machine 1 will be described in order.

[0017] [Overall Configuration of Injection Molding Machine 1] As shown in FIGS. 1 and 2, the injection molding machine 1 includes a support portion 10, a drive portion 30 supported by the support portion 10 and responsible for the forward and backward movement of the screw 101 and the rotation of the screw 101, and an injection portion 100 including the screw 101 and related to the injection of resin. The injection molding machine 1 controls the forward movement of the screw 101 and the cylinder 103 by the first movement mechanism 50 to supply molten resin toward the mold of a mold clamping device (not shown). In injection molding machine 1, the side labeled F in Figure 1, etc., is defined as the front, and the side labeled B is defined as the rear. The definitions of front F and rear B include a relative meaning. Furthermore, for injection molding machine 1, the width direction W, the longitudinal direction L, and the vertical direction H are defined as shown in Figure 1, etc.

[0018] [Support section 10: Figures 1 and 2] As shown in Figures 1 and 2, the support section 10 comprises a bed 11 extending from the front F to the rear B, a base 13 placed on the bed 11, and a pair of guide rails 15, 15 provided on the base 13 and on the rear B side of the base 13. As shown in Figure 2, a pair of guide rails 15, 15 are fixed on the base 13 with a gap in the width direction W. An intermediate plate 61 of the drive unit 30, which will be described later, is slidably mounted on the guide rails 15, 15 from the front F to the rear B, and from the rear B to the front F.

[0019] [Drive unit 30: Figures 1 and 2] Next, the drive unit 30 will be described. As shown in Figures 1 and 2, the drive unit 30 includes a front support unit 40 provided in front of the support unit 10 F, an intermediate support unit 60 provided behind the front support unit 40 B, and a rear support unit 80 provided behind the intermediate support unit 60 B.

[0020] [Front support section 40: Figures 1 and 2] As shown in Figures 1 and 2, the front support section 40 is supported on the base 13 of the support section 10, and its position is fixed. The front support section 40 supports the cylinder barrel 105. The front support section 40 also supports the first movement mechanism 50, which is responsible for the reciprocating movement of the intermediate support section 60 in the front-rear direction.

[0021] The front support section 40 comprises a front plate 41 having a plunger passage 43 that penetrates in the front-rear direction at the center of the width direction W, and first support holes 45, 45 that are connected in the front-rear direction near both ends of the width direction W. A screw 101 and a cylinder 103 are arranged to penetrate the plunger passage 43 in the front-rear direction. Ball screws 51, 51 are arranged to penetrate in the front-rear direction and are rotatable in the first support holes 45, 45, respectively.

[0022] [First moving mechanism 50: Figure 2] The first moving mechanism 50 reciprocates the intermediate support portion 60 in the front-rear direction. This movement of the intermediate support portion 60 is accompanied by the front-rear reciprocating movement of the cylinder 103 and the rear support portion 80. As shown in Figure 2, the first moving mechanism 50 comprises a pair of ball screws 51, 51 and electric motors 55, 55 that provide rotational driving force to each of the ball screws 51, 51. The first moving mechanism 50 also comprises input pulleys 53, 53 fixed to the respective input shafts 52, 52 of the ball screws 51, 51, and output pulleys 57, 57 fixed to the respective output shafts 56, 56 of the electric motors 55, 55. A transmission belt 58, 58 is wound between the input pulleys 53, 53 and the output pulleys 57, 57. Therefore, when the electric motors 55, 55 are driven to rotation, the ball screw shafts 51A, 51A of the ball screws 51, 51 rotate.

[0023] Each ball screw 51 comprises a ball screw shaft 51A and a ball screw nut 51B fitted onto the ball screw shaft 51A. The ball screw shaft 51A is rotatably supported in a first support hole 45 of the front plate 41 by a bearing (not shown), and the ball screw nut 51B is non-rotatably fitted into a second support hole 65 of the intermediate support portion 60. The ball screw nut 51B reciprocates in the front-rear direction as the ball screw shaft 51A rotates. Since this reciprocating movement is relative to the ball screw shaft 51A, the intermediate support portion 60 into which the ball screw nut 51B is fitted reciprocates as the ball screw nut 51B receives a front-rear thrust generated in the ball screw nut 51B as a result of the rotation of the ball screw shaft 51A.

[0024] Since the first moving mechanism 50 is configured as described above, when the electric motors 55, 55 rotate in the forward or reverse direction, the intermediate support section 60 moves back and forth. This movement is accompanied by the movement of the rear support section 80.

[0025] [Intermediate support section 60: Figures 1 and 2] Next, the intermediate support section 60 will be described. As shown in Figures 1 and 2, the intermediate support section 60 is supported by the guide rails 15, 15 of the support section 10 and is capable of reciprocating movement in the front-rear direction, that is, forward or backward movement. The intermediate support section 60 supports the cylinder 103 in a non-rotatable manner and also supports the pair of ball screw nuts 51B, 51B in a non-rotatable manner.

[0026] As shown in Figure 2, the intermediate support section 60 includes an intermediate plate 61 in which a plunger gripping hole 63 is formed in the center of the width direction W and is connected in the front-rear direction, and second support holes 65, 65 are formed near both ends of the width direction W and are connected in the front-rear direction. Inside the plunger gripping hole 63, the screw 101 and cylinder 103 are arranged to pass through in the front-rear direction. Ball screw nuts 51B, 51B are non-rotatably supported in each of the second support holes 65, 65. Ball screw shafts 51A, 51A are rotatably supported in the ball screw nuts 51B, 51B.

[0027] As described above, the intermediate support section 60 moves back and forth in the front-to-back direction when the electric motors 55, 55 rotate in the forward or reverse direction, accompanied by the cylinder 103.

[0028] The front end of the piston rod 95 of the second moving mechanism 90 is fixed to the rear end of the intermediate plate 61. The second moving mechanism 90 can widen or narrow the distance between the intermediate support 60 and the rear support 80 by applying thrust in the front-rear direction with the piston rod 95. The second moving mechanism 90 reciprocates the piston rod 95 in the forward and backward direction by supplying hydraulic fluid to the cylinder 91 from a hydraulic source (not shown in the figure). The second moving mechanism 90 has a cylinder 91 fixed to the rear support portion 80. Therefore, by reciprocating the piston rod 95 of the second moving mechanism 90 in the front-rear direction, the distance between the intermediate support portion 60 and the rear support portion 80 can be widened or narrowed.

[0029] As shown in Figure 1, the intermediate plate 61 has an inlet 67 formed along the vertical direction H for introducing solid resin, which is the raw material for injection molding. The inlet 67 penetrates from the top surface of the intermediate plate 61 to the plunger gripping hole 63 and is connected to the inlet 104 of the cylinder 103.

[0030] As shown in Figures 1 and 2, the intermediate support section 60 includes a frame 68 that is connected to the lower part of the intermediate plate 61 and extends toward the rear B. The frame 68 slidably supports the rear support section 80, which will be described later. Therefore, when the intermediate support section 60 reciprocates in the front-rear direction by the drive of the electric motor 55 and the ball screw 51, the frame 68 also reciprocates in the front-rear direction together with the intermediate support section 60.

[0031] A pair of guide rails 69, 69 are provided on the frame 68, spaced apart in the width direction W, and the rear support section 80 is made slidable in the front-rear direction on these guide rails 69, 69. As mentioned above, other means can be used to move the rear support section 80 back and forth in the front-rear direction.

[0032] [Rear support section 80: Figures 1 and 2] Next, the rear support section 80 will be described. As shown in Figures 1 and 2, the rear support section 80 is mounted on the frame 68 of the intermediate support section 60 so as to be able to reciprocate in the front-rear direction. In addition to rotatably supporting the screw shaft 101B of the screw 101, the rear support section 80 also supports the rotation mechanism 85 of the screw 101 and the second movement mechanism 90 which is responsible for the front-rear movement of the rear support section 80.

[0033] The rear support section 80 includes a rear plate 81 that houses an output shaft 83 that is connected in the front-rear direction at the center of the width direction W. This output shaft 83 is positioned to penetrate the rear plate 81 in the front-rear direction and is rotatably supported by the rear plate 81 via bearings (not shown). The output shaft 83 is also connected and fixed to the screw shaft 101B of the screw 101 by a coupling.

[0034] [Rotation mechanism 85: Figures 1 and 2] The rotating mechanism 85 rotates the screw 101 via the output shaft 83. As shown in Figures 1 and 2, the rotating mechanism 85 includes an electric motor 86 supported by a rear plate 81 and an output pulley 88 fixed to the output shaft 87 of the electric motor 86. The rotating mechanism 85 also includes an input pulley 110 fixed to an output shaft 83 connected to the screw shaft 101B and a transmission belt 89 wrapped between the output pulley 88 and the input pulley 110. The rotational motion of the electric motor 86 is transmitted to the output shaft 83 via the transmission belt 89, causing the screw 101 to rotate. Note that the pulley and belt are merely examples of means for transmitting the driving force from the rotation mechanism 85 to the output shaft 83 connected to the screw shaft 101B; known speed reducers such as parallel gear reducers, helical gear reducers, bevel gear reducers, hypoid reducers, or other power transmission mechanisms can also be used.

[0035] [Second movement mechanism 90: Figures 1 and 2] The second movement mechanism 90 moves the rear support section 80 back and forth in the front-rear direction. This back-and-forth movement of the rear support section 80 is performed along the guide rail 69 of the frame 68 and is relative to the intermediate support section 60. In this embodiment, the second moving mechanism 90 consists of a hydraulic cylinder as a second drive source and comprises a pair of cylinders 91, 91 provided at both ends in the width direction W of the rear plate 81, pistons 93, 93 arranged inside each of the cylinders 91, 91, and piston rods 95, 95 connected to each of the pistons 93, 93. Each cylinder 91 has a first oil chamber 94F located F in front of the piston 93 and a second oil chamber 94B located B behind the piston 93. The front ends of the piston rods 95, 95, which serve as second moving members, are connected to and fixed to the intermediate plate 61.

[0036] Since the second moving mechanism 90 has the above configuration, when hydraulic fluid is supplied to the first oil chamber 94F, the rear plate 81 is moved forward (forward) by the thrust from the piston rod 95, and the distance between the intermediate support 60 and the rear plate 81 narrows. Also, when hydraulic fluid is supplied to the second oil chamber 94B, the rear plate 81 is moved backward (backward) by the thrust from the piston rod 95, and the distance between the intermediate support 60 and the rear plate 81 widens.

[0037] [Summary of the drive unit 30] The front support section 40, intermediate support section 60, and rear support section 80 of the drive unit 30 have been described, and a summary of each is given below. A: Front support part 40 (a) The cylinder barrel 105 is supported at its front end in a fixed position on the base 13, and the screw 101 and cylinder 103 pass through it so as to be movable in the front-rear direction. (b) Supports the first movement mechanism 50 which is responsible for the forward and backward movement of the intermediate support section 60. B: Intermediate support part 60 (a) The electric motor 55 reciprocates in the front-to-back direction while supporting the cylinder 103. (b) A frame 68 that supports the rear support section 80 is integrally provided. C: Rear support part 80 (a) The output shaft 83, which is connected to the screw 101, is rotatably supported and moves back and forth together with the intermediate support 60. It also moves back and forth in the forward and backward direction relative to the intermediate support 60. (b) Supports a rotating mechanism 85 that rotates the output shaft 83 connected to the screw 101. (c) Supports the second movement mechanism 90, which is responsible for the reciprocating movement in the front-rear direction relative to the intermediate support 60.

[0038] [Injection unit 100: Figures 1 and 2] As shown in Figures 1 and 2, the injection unit 100 comprises a screw 101 and a cylindrical cylinder 103 that surrounds almost the entire longitudinal direction L of the screw 101. The injection unit 100 also comprises a cylindrical cylinder barrel 105 into which the cylinder 103 and screw 101 are inserted, located in front of the front support unit 40 F, and an injection nozzle 107 provided at the front end of the cylinder barrel 105. The cylinder 103 and cylinder barrel 105 are included in the concept of a housing equipped with a heater in a resin molding machine.

[0039] The screw 101 comprises a body 101A with a helical groove formed on its outer circumference, and a screw shaft 101B connected to the rear end of the body 101A. The screw 101 is connected to the output shaft 83. The output shaft 83 penetrates the rear support portion 80 in the front-rear direction and is rotatably supported by the rear support portion 80. The input pulley 110 of the rear support portion 80 is fixed to the rear end of the output shaft 83 that is exposed to the rear B after passing through the rear support portion 80. However, the output shaft 83 is fixed to the rear support portion 80 in the front-rear direction. Therefore, the screw 101 can reciprocate in the front-rear direction in conjunction with the reciprocating movement of the rear support portion 80 in the front-rear direction.

[0040] The cylinder 103 is fixed to the intermediate support portion 60 by fitting into the plunger gripping hole 63. Therefore, the cylinder 103 can reciprocate in the front-rear direction as the intermediate support portion 60 moves back and forth. The cylinder 103 has an inlet 104 into which raw materials made of solid resin, which are used as raw materials for injection molding, are introduced. The inlet 104 penetrates both the inside and outside of the cylinder 103. The inlet 104 communicates with an inlet 67 formed in the intermediate support section 60. Furthermore, the cylinder 103 is equipped with a discharge port 103A at its front end through which the resin melted by the screw 101 inside the cylinder 103 is discharged to the outside. The screw 101, housed inside the cylinder 103, can reciprocate in the forward and backward directions and rotate within the cylinder 103. The cylinder 103 is surrounded by heaters 108, such as band heaters and cartridge heaters. By supplying power to the heaters 108 from a power source (not shown), the resin material inside the cylinder 103 is heated. Although the heaters 108 shown in Figures 1 and 2 are mounted on the outer circumference of the cylinder 103, they can also be built into the cylinder 103, similar to the heater 109 provided on the cylinder barrel 105.

[0041] The cylinder barrel 105 is fixed to the front support portion 40. Since the position of the front support portion 40 is fixed to the base 13, the position of the cylinder barrel 105 is also fixed to the base 13. However, within the cylinder barrel 105, the cylinder 103 can reciprocate in the front-rear direction, and the screw 101 can rotate and reciprocate in the front-rear direction within the cylinder 103.

[0042] The cylinder barrel 105 comprises a barrel body 105A and a flange 105B integrally formed with the barrel body 105A and responsible for fixing the cylinder barrel 105 to the front plate 41. The cylinder barrel 105 has a circular heater chamber 105C that extends from the front F to the rear B, penetrating the barrel body 105A and the flange 105B, and the front F portion of the cylinder 103 is housed in this heater chamber 105C. Although the heater 109 of the cylinder barrel 105 is not shown in Figures 1 and 2, as will be described later, the heater 109 is built into the flange 105B. Furthermore, the barrel body 105A and the flange 105B correspond to the solid portion in this invention.

[0043] The injection nozzle 107 is fixed to the front end of the cylinder barrel 105. Since the position of the cylinder barrel 105 is fixed, the position of the injection nozzle 107 is also fixed. The injection nozzle 107 includes an injection hole 107A provided at its front end and a resin passage 107B connected to the injection hole 107A. The molten resin, plasticized and metered by the screw 101, is injected through the resin passage 107B and the injection hole 107A into a mold cavity (not shown).

[0044] [Arrangement of heaters 109 built into cylinder barrel 105: See Figures 3, 4, and 5] The cylinder barrel 105 incorporates, for example, a heater 109 that uses an electric heating wire as a heat source. By supplying power to the heater 109 from a power source (not shown), the resin material inside the cylinder barrel 105 and cylinder 103 can be heated. The cylinder barrel 105 is characterized by an arrangement of one or more heaters 109, as will be explained below with reference to Figures 3 to 5. This arrangement of heaters 109 is based on an arrangement of multiple heater chambers 105C that hold the heaters 109, formed in the solid portion of the cylinder barrel 105.

[0045] In the barrel body 105A, which is the solid part of the cylinder barrel 105, straight heaters 109 are arranged according to the following first, second, and third elements. Note that in Figures 3 to 5, the heater 109 is shown as a simple line segment, and this heater 109 is housed in the heater chamber 105C.

[0046] First element (Figure 3): The heater 109 is installed along a direction intersecting the axial direction AD. Each heater 109 (heater chamber 105C) is provided along a direction intersecting the axial direction AD in the barrel body 105A. In Figure 3(a), as a typical example, the heater 109 is formed along a direction perpendicular to the axial direction AD. Also, as shown in Figures 3(b) and (c), the heater 109 can intersect the axial direction AD at any angle and in any direction other than perpendicular. However, if the angle θ at which it intersects the axial direction AD is too small or too large and approaches parallel to the axial direction AD, the overall length of the heater 109 will increase, which is undesirable. Therefore, the angle θ is preferably in the range of 45° to 90° (or 90° to 135°), and more preferably in the range of 60° to 90° (or 90° to 120°). Note that Figure 3 shows an example where there is one heater 109 (heater chamber 105C) along the axial direction AD.

[0047] Second element (Figure 4): One or more heaters 109 are arranged in the axial direction AD. Figure 4 shows an example in which multiple heaters 109 are arranged with spacing in the axial direction AD. In this example, Figure 4(a) shows an example in which multiple heaters 109, as an example, three heaters 109 are arranged at uneven spacing. Figure 4(b) shows an example in which multiple heaters 109, as an example, five heaters 109 are arranged at equal spacing (L1). When there are three or more heaters 109 (heater chambers 105C), the spacing in the axial direction AD may be equal as shown in Figure 4(b) or uneven as shown in Figure 4(a). Alternatively, when there are multiple groups of heaters, the spacing of some groups of heaters may be even, while the spacing of the other groups of heaters may be uneven. Heater groups will be described later. In addition, the positions of the multiple heater chambers 105C may coincide or differ in the circumferential direction CD.

[0048] Furthermore, Figure 4(c) shows an example with three heaters 109, each having a U-shape. The U-shaped heater 109 is a heater that includes a straight section. Even though the heater 109 is U-shaped, it has two (a pair of) straight sections excluding the folded-over section U, so the two straight sections can be housed by providing a pair of straight heater chambers 105C corresponding to each of them. In this case, each folded-over section U is exposed from the pair of straight heater chambers 105C. The three heaters 109 are controlled to have different heating temperatures during injection molding, and each is responsible for heating in the temperature control zones Z1, Z2, and Z3.

[0049] Third element (Figure 5): Arrangement of multiple heaters 109 (heater chambers 105C) in the circumferential direction CD. Figure 5 shows an example in which multiple heaters 109 are arranged at intervals along the circumferential direction CD. In this example, Figures 5(a) and (b) show two heaters 109 arranged parallel to each other along the circumferential direction CD. In Figure 5(a), the radial distances of the two 109 from the central axis C of the cylinder barrel 105 are uneven, R1 ≠ R2, whereas in Figure 5(b), the radial distances of the two 109 from the central axis C of the cylinder barrel 105 are equal, R1 = R1. Figures 5(c) and (d) show examples of arrangements in which a hollow section 105D is incorporated by multiple heaters 109. In this example, Figure 5(c) shows a group of heaters 109G composed of four heaters 109 arranged in a rectangular shape, and Figure 5(d) shows a group of heaters 109G composed of three heaters 109 arranged in a triangular shape. In Figures 5(c) and 5(d), each heater 109 constituting the heater group 109G is arranged with different phases around the central axis C. When two or more heaters 109 (heater chambers 105C) are provided along the circumferential direction CD, the spacing or phase may be equal or uneven. Furthermore, the positions of the multiple heaters 109 (heater chambers 105C) in the axial direction AD may coincide or differ. Also, although each heater chamber 105C in Figure 5 is shown as a through-hole for easier processing, it may also be a heater chamber with a dead-end hole instead of a through-hole.

[0050] The cylinder barrel 105, shown in Figures 6 and 7, which constitutes the injection molding machine 1, has the following selections made for its first to third elements, and the barrel body 105A is equipped with a total of eight heaters 109 (heater chambers 105C). First element: Heater 109 (heater chamber 105C) is oriented in a direction perpendicular to the axial direction AD. Second element: Multiple heaters 109 (heater chambers 105C) are arranged at equal intervals in the axial direction A and D. Third element: Multiple heaters 109 (heater chambers 105C) are arranged along the circumferential direction CD and in different phases.

[0051] The heater 109 applied to this embodiment includes heaters such as sheathed heaters and cartridge heaters, which have at least part or all of their components as straight sections. Both sheathed heaters and cartridge heaters share the characteristic of having a spirally wound heating wire inserted into a metal tube, and the inside of the tube filled with a highly heat-conductive insulator, such as magnesium oxide (MgO). Typically, heaters with lead wires extending from both ends of the tube are called sheathed heaters, and heaters with lead wires extending from one end of the tube are called cartridge heaters.

[0052] The heater 109 shown here consists entirely of a straight section, but as illustrated in Figure 4(c), a heater 109 that includes a straight section in part can also be used in this embodiment. In other words, the section within the heater chamber 105C, from the end portion housed in the heater chamber 105C to the portion exposed from the heater chamber 105C, only needs to be a straight section, and the portion exposed from the heater chamber 105C may be curved, bent, or otherwise. Furthermore, while the cross-sectional shape of the heater 109 is typically circular, heaters with rectangular or other polygonal cross-sectional shapes can also be used.

[0053] [Operation of injection molding machine 1: Figures 8 and 9] Next, the operation of the injection molding machine 1 will be described with reference to Figures 8 and 9. The operation of the injection molding machine 1 described here includes the following: Heaters 108 and 109 are heated at appropriate times during the following injection operation process. Figure 8(a): Preparation for plasticization and metering (resin channel opening operation) Figure 8(b): Plasticization and metering (molten resin dispensing) Figure 9(a): Preparation for injection (resin flow path closing operation) Figure 9(b): Injection molding (filling the cavity with resin)

[0054] [Preparation for plasticization and metering (resin channel opening operation): Figure 8(a)] As shown in Figure 8(a), the screw 101 is retracted by a small stroke from the discharge port 103A of the cylinder 103, opening the discharge port 103A. This creates a resin flow path between the tip of the screw 101 and the cylinder 103, connecting the inside of the cylinder 103 and the cylinder barrel 105, enabling the supply of molten resin to the inside of the cylinder barrel 105. After this, the molten resin plasticized inside the cylinder 103 flows into the inside of the cylinder barrel 105, allowing the cylinder 103 to retract and measure the amount of molten resin to fill the mold cavity. To form the resin flow path, the second moving mechanism 90 is operated to retract the rear support portion 80 relative to the intermediate support portion 60. In other words, as the rear support portion 80 retracts, the screw 101 connected to the rear plate 81 of the rear support portion 80 retracts. At this point, the intermediate support section 60 and the rear support section 80 are positioned at their furthest forward position, that is, at or near their forward limit.

[0055] [Plasticization and metering (molten resin discharge): Figure 8(b)] Next, the resin material is plasticized by rotating the screw 101. As a prerequisite, a predetermined amount of resin material is introduced through the input ports 67 and 104. The rotation of the screw 101 is achieved by driving the electric motor 86. The direction of rotation of the screw 101 and the electric motor 86 at this time is defined as forward rotation.

[0056] The electric motor 55 of the first moving mechanism 50 is rotated either in sync with or independently of the rotation of the screw 101. This rotation is defined as forward rotation. When the electric motor 55 rotates forward, the intermediate support section 60 and the rear support section 80 retract together. This is because the rear support section 80 is mounted on the frame 68 of the intermediate support section 60. As the intermediate support section 60 and the rear support section 80 retract, the screw 101 and the cylinder 103 retract. Through this series of operations, the plasticized and molten resin is discharged into and stored inside the cylinder barrel 105. By identifying the retracted positions of the screw 101 and the cylinder 103, the amount of molten resin to be discharged can be determined (measured). Once a predetermined amount has been measured, the rotation of the screw 101 stops, and the retraction movement of the first moving mechanism 50 also stops.

[0057] Figure 8(b) shows the cylinder 103 in the position where the metering of the molten resin has been completed in the series of processes described above, i.e., the metering completion position of the cylinder 103. At this metering completion position, the rear B portion of the stand 68 is shown protruding from the base 13 to the rear B, forming a cantilevered shape. Note that the cantilevered shape is formed partway through reaching the retraction limit position.

[0058] [Preparation for injection (resin flow path closing operation): Figure 9(a)] Next, in preparation for the injection operation, the screw 101 is advanced a small amount and brought into contact with the discharge port 103A of the cylinder 103, closing the resin flow path that had been formed so far, as shown in Figure 9(a). This operation is the reverse of the preparation for plasticization and metering described earlier, and by operating the second moving mechanism 90, the rear support portion 80 is advanced a small amount toward the intermediate support portion 60.

[0059] [Injection molding (filling the cavity with resin): Figure 9(b)] Once the resin channel is closed, the screw 101 and cylinder 103 are advanced to inject the molten resin into the mold cavity. At this time, the intermediate support section 60 and the rear support section 80 are advanced by reversing the electric motor 55. As a result, the screw 101 moves forward together with the cylinder 103, and the molten resin that had been stored in front of the screw 101 F inside the cylinder barrel 105 is injected from the nozzle towards the mold cavity (not shown). At this time, the screw 101 tries to move backward relative to the front end of the cylinder 103 due to the injection pressure. However, the screw 101 is pressed forward by the second moving mechanism 90 to prevent the discharge port 103A from opening and the molten resin inside the cylinder barrel 105 from flowing back into the cylinder 103. When cylinder 103 moves forward to its predetermined position, the filling of the cavity with molten resin for one cycle is complete. Preparation for the next cycle is then carried out.

[0060] [effect] The following explains the effects of injection molding machine 1. <First effect: Ease of replacing heater 109> The heater 109 is housed in a heater chamber 105C oriented perpendicular to the axial direction AD of the cylinder barrel 105. Because there is relatively ample space around the cylinder barrel 105 in the radial direction, the heater 109 can be easily replaced using this space.

[0061] Since the cylinder barrel 105 is joined to the front plate 41 at the rear B and to the injection nozzle 107 at the front F, there is no space to replace the heater 109 as is. Therefore, if the heater chamber 105C is provided in the axial direction AD, in order to insert, remove, and replace the heater 109, it would be necessary to remove the cylinder barrel 105 from the front plate 41 or remove the injection nozzle 107 from the cylinder barrel 105, which would result in poor workability.

[0062] This is also true if the heater 108 is built into the axial AD of the cylinder 103. In other words, the drive unit 30, including the electric motor 86, is provided on the rear (R) side of the cylinder 103, and the space between the cylinder 103 and the drive unit 30 is narrow, making it difficult to replace the heater 108. The front F side of the cylinder 103 is surrounded by the cylinder barrel 105, making it difficult to replace the heater 108. In contrast, if the heater chamber is provided in the area where the heater 108 is installed, as shown in Figures 1 and 2, and intersects the axial AD of the cylinder 103, then space is secured around it, making it easy to replace the heater 108.

[0063] <Second effect: High machining accuracy of heater chamber 105C> The heater chamber 105C, provided in the barrel body 105A, is oriented perpendicular to the axial direction A and D. Therefore, the slenderness ratio of the heater chamber 105C is small and its overall length can be kept short. Consequently, the machining accuracy of the heater chamber 105C is high because it is easy to machine.

[0064] The cylinder barrel 105 has a large axial dimension AD, making it long. If a heater chamber is to be provided in the axial direction AD, it is necessary to create a heater chamber with a large slenderness ratio and a long length by drilling. In this case, a drill or other machining tool with a large slenderness ratio and a long length will be used, but a large slenderness ratio makes the tool prone to wobbling and runout during machining. This could result in the hole bending or meandering during the machining of the heater chamber, leading to low machining accuracy and potentially preventing the smooth fitting of the heater.

[0065] <Third effect: Improved heating accuracy in the temperature control zone> The heating temperature during molding operation using multiple heaters 109 in the cylinder barrel 105 is not necessarily constant in the axial direction AD. For example, as shown in Figure 4(c), multiple temperature control zones (Z1 to Z3) may be set in the axial direction AD, and each temperature control zone (Z1 to Z3) may have a different heating temperature. The same applies to the heater 108 in the cylinder 103. A cylinder barrel 105 that can house heaters 109 in directions intersecting, typically orthogonal to, the axial AD allows for the arrangement and construction of a sufficient number of heaters 109 to individually and independently adjust the heating temperature for each temperature control zone. Therefore, even if the axial AD range of each temperature control zone is set to a short length, high-precision control is possible.

[0066] In contrast, if the heaters 109 are arranged parallel to the axial AD, the temperature control zone handled by each heater 109 becomes long, making it difficult to set a short range for the axial AD of the temperature control zone. This is acceptable for about two temperature control zones, but if it is necessary to have three or more temperature control zones, the heaters 109 must be divided in the longitudinal direction, which cannot be accommodated with an arrangement of heaters 109 parallel to the axial AD. Furthermore, in order to provide heaters 109 parallel to the axial direction AD, they can be housed in multiple heater chambers (105C) arranged in the circumferential direction CD. In this case, each heater chamber (105C) can be associated with each temperature control zone. However, if the heater chambers 105C are small in diameter, the number of heater chambers (105C) that can be arranged in the circumferential direction CD is small. Therefore, if the number of temperature control zones is to be increased, the number of heater chambers 105C corresponding to each temperature control zone will decrease. As a result, the number of heaters 109 that heat each temperature control zone will also decrease, which may lead to insufficient or uneven heating of each temperature control zone, reducing the heating accuracy of each temperature control zone and potentially causing temperature control failure.

[0067] <Fourth effect: Reduction of uneven heating in the circumferential CD> The cylinder barrel 105 can surround the resin passage 107B by equipping it with multiple heaters 109 arranged with different phases in the circumferential direction CD. Therefore, the cylinder barrel 105 can heat the molten resin stored in the resin passage 107B from the entire circumferential direction CD, thus preventing temperature variations in the circumferential direction CD, i.e., uneven heating, or minimizing any such variations. The same applies to the cylinder 103. This ensures that the heating and thermal expansion of the cylinder barrel 105 proceeds as intended in the design, preventing unexpected component damage or failure, specifically, preventing the cylinder barrel 105 from bending in an unintended direction relative to the central axis C. This prevents problems such as galling wear (adhesion wear) in the sliding parts of the cylinder 103 or screw 101 built into the cylinder barrel 105.

[0068] In contrast to the above, let's assume that multiple heater chambers 105C and multiple heaters 109 are formed in the axial direction A and D. If a large number of heaters 109 are provided to surround the circumferential direction CD of the resin passage 107B, heating unevenness in the circumferential direction CD can be suppressed. However, in reality, there is a limit to the number of heaters 109 that can be provided at equal intervals in the circumferential direction CD. In this arrangement of heaters 109, the heating temperature in the region between the heaters 109 will inevitably be lower, so heating unevenness is likely to occur in the circumferential direction CD.

[0069] In addition to the above, it is possible to select or replace the configurations listed in the above embodiments, or to change them to other configurations as appropriate, as long as it does not deviate from the spirit of the present invention. In this embodiment, among the cylinder 103 and cylinder barrel 105, an example is shown in which the heater 109 is provided in the cylinder barrel 105, which is equipped with a heater 109, along a direction intersecting the axial AD. However, as already mentioned, the heater 108 can also be provided along a direction intersecting the axial AD for the cylinder 103, which corresponds to the housing in the present invention, similar to the cylinder barrel 105. Furthermore, the heaters in the housing equipped with other heaters for the cylinder 103 and cylinder barrel 105 can also be provided along a direction intersecting the axial AD. Furthermore, in this embodiment, as merely one example of the present invention, we have shown an example in which the heater 109 is applied to the cylinder barrel 105 of a special injection device structure that injects molten resin into the cavity of a mold by advancing a screw 101 and a cylinder 103 inserted inside the cylinder barrel 105. However, it goes without saying that the invention is not limited to this, and the heater of the present invention can be applied to the heating of a cylinder into which a plasticizing screw is inserted in an extrusion molding machine or injection molding machine with a general structure (for example, an in-line injection molding machine). [Explanation of symbols]

[0070] 1 injection molding machine 10 Support part 11 beds 13 Base 15 Guide rails 30 Drive unit 40 Front support part 41 Front plate 43 Plunger passage 45 First support hole 50 First movement mechanism 51A Ball screw shaft 51B Ball screw nut 52 Input axes 53 Input Pulley 55 Electric motor 56 Output shaft 57 Output pulley 58 Transmission belt 60 Intermediate support part 61 Intermediate plate 63 Plunger gripping holes 65 Second support hole 67,104 Inlet 68 mounting bases 69 Guide rails 80 Rear support part 81 Rear plate 83 Output shaft 85 Rotation mechanism 86 Electric motor 87 Output shaft 88 Output Pulley 89 Transmission belt 90 Second movement mechanism 91 Cylinder 93 Pistons 94B Second oil room 94F First oil room 95 Piston Rod 96 First Regulatory Body 100 Injection part 101 Screw 101A Main Unit 101B Screw shaft 103 Cylinder 103A Discharge port 104 Inlet 105 Cylinder Barrel 105A Barrel Body (Housing Body) 105B Flange 105C Heater Room 105D Hollow part 106 Coupling 107 Injection Nozzle 107A injection hole 107B Resin passage 108,109 Heater 110 Input Pulley

Claims

1. A cylindrical housing body having an axial direction and a circumferential direction, comprising a hollow portion and a solid portion surrounding the hollow portion, The solid portion is housed in one or more heaters, each having at least a straight portion in part or in whole. The heater is provided with the straight portion arranged in a direction intersecting the axial direction, A heating housing for a resin molding machine, characterized in that the plurality of heaters are arranged along the circumferential direction and in different phases around the central axis.

2. Multiple heaters are arranged at different positions in the axial direction at equal or uneven intervals. The heating housing according to claim 1.

3. At the same position in the axial direction, a plurality of heaters are provided as a group of heaters with different phases in the circumferential direction. A heating housing according to claim 1 or claim 2.

4. The plurality of heater groups are provided at different positions in the axial direction, The heating housing according to claim 3.

5. Each of the heater groups provided at different positions in the axial direction has a different heating temperature. The heating housing according to claim 4.

6. The housing body is The housing body is provided with a heater chamber consisting of one or more straight voids formed in the solid portion, intersecting the axial direction of the housing body. The straight portion of the heater is housed in the heater chamber. A heating housing according to claim 1 or claim 2.

7. A resin molding machine comprising a screw for plasticizing a resin and a heating housing according to claim 1 or claim 2 that surrounds the screw.

8. A cylindrical shape having an axial direction and a circumferential direction, comprising a hollow portion and a solid portion surrounding the hollow portion. The housing body and One or more components, each containing at least part or all of a straight portion, are embedded within the solid portion. Equipped with a heater, The heater is provided with the straight portion arranged in a direction intersecting the axial direction, Multiple heaters are provided as a group of heaters at the same position in the axial direction, Multiple groups of heaters are provided at different positions in the axial direction. A heating housing for a resin molding machine, characterized in that multiple groups of heaters can individually and independently adjust their heating temperatures in accordance with their respective temperature control zones.

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