Kneading machine

Abstract

A kneader is provided in which the rotation of each screw can be easily switched between the same direction and the opposite direction using one motor. [Solution] A kneading machine for kneading a viscous material within a barrel, comprising: a drive shaft provided with a drive gear; a first driven shaft provided with a driven gear that meshes with the drive gear; a second driven shaft provided with a first selection gear that meshes with the drive gear and a second selection gear that meshes with the driven gear, and to which rotation of the drive shaft is transmitted from either the first selection gear or the second selection gear; a first screw housed within the barrel and having a first kneading blade formed around its periphery; a second screw provided adjacent to the first screw and having a second kneading blade formed around its periphery that meshes with the first kneading blade; and a rotation selection unit that can select either meshing between the drive gear and the first selection gear or meshing between the driven gear and the second selection gear.

Description

[Technical Field]

[0001] The present invention relates to a kneading machine. [Background technology]

[0002] Kneaders are known as devices that uniformly mix resin materials such as rubber and plastics by applying external forces such as shear. Known kneaders include continuous kneaders that continuously extrude a mixture of mixed resin materials, and batch kneaders that mix small amounts of resin materials and alternately knead and stop mixing. Continuous kneaders are characterized by high production efficiency, while batch kneaders are characterized by their ability to reduce testing costs for mixing. Patent Document 1 is an example of such a batch kneader.

[0003] Patent Document 1 discloses an invention of an extruder for processing small amounts of material. The extruder has a pair of intermeshing extruder screws. The pair of extruder screws is housed in a barrel formed by a housing block, and each is connected to a drive unit via a coupling means. Material supplied into the barrel is processed by the rotation of the pair of extruder screws, and is circulated within the barrel through a recirculation channel communicating with the barrel. The recirculation channel is formed for the purpose of increasing the residence time of the material being processed. This makes it possible for the extruder to extend the material processing time without lengthening the barrel or extruder screws, and to process small amounts of material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication 2014-525358 Summary of the Invention [Problem to be solved by the invention]

[0005] In the extruder, each of the pair of extruder screws is connected to a drive unit that rotates the extruder screws via the coupling means, thereby rotating each extruder screw and controlling the rotation directions of each extruder screw to be in the same direction or opposite directions. Therefore, the extruder needs to provide a drive unit corresponding to each extruder screw, which may result in an increase in the size of the device. Furthermore, since the blades provided around the pair of extruder screws are intermeshed with each other, the rotation speeds per unit time of each extruder screw must be synchronized. Therefore, the extruder needs to develop a control program for synchronizing the rotation of each extruder screw. Therefore, there has been a demand for a batch-type kneader that can easily switch between the same rotation direction and the opposite rotation direction of each screw while reducing the number of parts and making it smaller. [Means for solving the problem]

[0006] The present invention has been made in consideration of such problems, and its object is to provide a kneader that mixes multiple viscous materials using a pair of screws, and that can easily switch between rotating the screws in the same direction or in opposite directions using a single motor.

[0007] That is, the present invention provides a kneading machine that kneads different types of viscous materials in a barrel having a kneading space for the viscous materials formed inside and transports the viscous materials toward a barrel outlet, and includes: a drive shaft to which rotation of a motor is transmitted and which is provided with a drive gear; a first driven shaft which is provided with a driven gear that meshes with the drive gear; a second driven shaft which is provided with a first selection gear that meshes with the drive gear and a second selection gear that meshes with the driven gear and to which rotation of the drive shaft is transmitted from either the first selection gear or the second selection gear; a first screw connected to one end of the first driven shaft and housed in the barrel and having a first kneading blade formed around it; a second screw connected to one end of the second driven shaft and provided adjacent to the first screw in the barrel and having a second kneading blade formed around it that meshes with the first kneading blade; and a rotation selection unit that can select either meshing between the drive gear and the first selection gear or meshing between the driven gear and the second selection gear. [Effects of the Invention]

[0008] According to the kneader of the present invention, a single motor for rotating a drive gear can rotate the first screw and the second screw in the barrel in the same or opposite directions. Therefore, the kneader can reduce the number of parts compared to conventional kneaders in which a motor is connected to each screw as a drive source and the direction of rotation of the motor is changed to switch between same-direction rotation and opposite-direction rotation of the screws, thereby achieving a more compact device. Furthermore, while the kneader uses shafts and gears to switch between same-direction rotation and opposite-direction rotation of the screws, the kneader can switch between same-direction rotation and opposite-direction rotation using only three shafts: the drive shaft, the first driven shaft, and the second driven shaft, which also contributes to a more compact device. Furthermore, the kneader can easily switch between same-direction rotation mode and opposite-direction rotation mode using a rotation selection unit. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a plan view of a kneader according to an embodiment of the present invention. [Figure 2] 1 is a side view of a kneader according to one embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing the arrangement relationship of each gear in a same-direction rotation mode of the kneader according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing the arrangement relationship of each gear in a counter-rotation mode of the kneader according to one embodiment of the present invention. [Figure 5] FIG. 4 is a diagram showing the meshing state of each gear in a counter-rotation mode of the kneader according to one embodiment of the present invention, as viewed from the axial direction. [Figure 6] FIG. 10 is a diagram showing the arrangement relationship of each gear in a same-direction rotation mode of a kneader according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing the arrangement relationship of each gear in a counter-rotation mode of the kneader according to the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] The kneader of the present invention will be described in detail below with reference to the accompanying drawings.

[0011] FIG. 1 is a plan view of a kneader 100 according to one embodiment of the present invention, and FIG. 2 is a side view of the kneader 100. The kneader 100 can receive a plurality of viscous materials from a supply port 120. The kneader 100 can knead different types of viscous materials in a conical barrel 110 having a kneading space formed therein for the viscous materials, and can transport the viscous materials toward a barrel outlet 111. The barrel 110 is installed horizontally within the kneader 100, and the viscous materials in the barrel 110 are transported horizontally. While various viscous materials can be used, such as resin materials, food materials, chemical materials, and pharmaceutical materials, the present embodiment will be described using a resin material as an example.

[0012] As shown in Fig. 1, the kneader 100 has a first screw 130 and a second screw 140 housed in the barrel 110. The first screw 130 and the second screw 140 are so-called conical screws that have a conical shape that gradually narrows toward the tip. A first kneading blade 131 is formed around the first screw 130. The second screw 140 is provided adjacent to the first screw 130 inside the barrel 110, and a second kneading blade 141 that meshes with the first kneading blade 131 is formed around the second screw 140. The first screw 130 and the second screw 140 are configured to be replaceable with screws having kneading blades of different shapes.

[0013] The first screw 130 and the second screw 140 can rotate in the same direction or in the opposite directions using a gear mechanism described later. A rotation selection unit described later can be used to switch between a same-direction rotation mode, in which the first screw 130 and the second screw 140 rotate in the same direction, and a counter-direction rotation mode, in which the first screw 130 and the second screw 140 rotate in the opposite directions. In the case of same-direction rotation, both the first kneading blade 131 and the second kneading blade 141 are formed clockwise relative to the screws. On the other hand, in the case of counter-direction rotation, one of the first kneading blade 131 and the second kneading blade 141 is formed clockwise relative to the screws, and the other is formed counter-clockwise relative to the screws. By rotating the first screw 130 and the second screw 140 in the same direction or in the opposite directions, the kneader 100 can knead the viscous material in the barrel 110 while applying shear force to it and transport it toward the barrel outlet 111.

[0014] As long as the first screw 130 and the second screw 140 can mesh with each other while kneading the viscous material, the blade shape and the setting of the clearance during kneading can be changed as desired. Furthermore, in the kneader 100 of this embodiment, the first screw 130 and the second screw 140 are configured as conical screws, but the first screw 130 and the second screw 140 may also be configured as cylindrical parallel screws formed with the same diameter in the axial direction.

[0015] When a viscous material is supplied into the barrel 110, the kneader 100 rotates the first screw 130 and the second screw 140 in the same direction or in opposite directions to knead the viscous material in the barrel 110 and transport it toward a barrel outlet 111. The kneader 100 has a plurality of heaters 150 around the barrel 110, and is capable of controlling the temperature of the viscous material in the barrel 110. The kneader 100 also has a pressure gauge 160 for measuring the pressure at a predetermined position in the barrel 110. The barrel outlet 111 is connected to a valve 170 that changes the flow direction of the viscous material. The valve 170 can switch the flow direction of the viscous material transported to the barrel outlet 111 to either an outlet 180 for discharging the kneaded material from the kneader 100 or a circulation flow path 190. The circulation flow path 190 is intended to repeatedly circulate the viscous material within the barrel 110 to extend the kneading time, and can send the viscous material transported to the barrel outlet 111 by the first screw 130 and the second screw 140 back upstream of the barrel 110.

[0016] Next, a description will be given of a gear mechanism for rotating the first screw 130 and the second screw 140. The kneader 100 has a motor 200 as a drive source, a drive shaft 300 to which the rotation of the motor 200 is transmitted, a first driven shaft 400 that rotates following the rotation of the drive shaft 300, a second driven shaft 500 that rotates following the rotation of the drive shaft 300, and a rotation selecting unit 600 that can switch the kneader 100 between a same-direction rotation mode and a counter-direction rotation mode.

[0017] 2, the drive shaft 300 is rotatably supported within the kneader 100 and is provided at a slight incline with respect to the horizontal direction. The drive shaft 300 has a drive gear 310 that rotates in conjunction with the rotation of the drive shaft 300. The central axis of the drive gear 310 coincides with the central axis of the drive shaft 300. The drive gear 310 is a tapered bevel gear that narrows from one end to the other.

[0018] The first driven shaft 400 is rotatably supported within the kneader 100 and is provided above the drive shaft 300. The first screw 130 disposed within the barrel 110 is connected to one end of the first driven shaft 400. As shown in FIG. 1 , the first driven shaft 400 is provided at an angle with respect to the drive shaft 300. The first driven shaft 400 has a driven gear 410 that rotates in accordance with the rotation of the first driven shaft 400. The central axis of the driven gear 410 coincides with the central axis of the first driven shaft 400.

[0019] The driven gear 410 is a tapered bevel gear that narrows from one end to the other. The maximum diameter of the driven gear 410 is smaller than the minimum diameter of the drive gear 310, and is configured to always mesh with a part of the drive gear 310. Therefore, the driven gear 410 is rotated by the drive gear 310 by meshing with the drive gear 310. As a result, the first driven shaft 400 can rotate together with the driven gear 410, which is rotated by the drive gear 310, and can therefore be rotated following the rotation of the drive shaft 300.

[0020] The second driven shaft 500 is rotatably supported within the kneader 100 and is provided above the drive shaft 300. As shown in FIG. 2, the second driven shaft 500 is provided so as to overlap the first driven shaft 400 in the horizontal direction. The second screw 140 disposed within the barrel 110 is connected to one end of the second driven shaft 500. As shown in FIG. 1, the second driven shaft 500 is provided so as to be inclined with respect to the drive shaft 300. Therefore, when the kneader 100 is observed from above, the first driven shaft 400 and the second driven shaft 500 are provided in a substantially V-shape with the inter-axial distance gradually decreasing toward one end. The drive shaft 300, the first driven shaft 400, and the second driven shaft 500 are inclined relative to one another. In the kneader 100 of this embodiment, the drive shaft 300 is disposed below the first driven shaft 400 and the second driven shaft 500, but there are no limitations on the position of the shafts as long as the gears provided on the shafts can mesh under the conditions described below. In addition, when parallel screws are used as the first screw 130 and the second screw 140, the first driven shaft 400 and the second driven shaft 500 do not need to be disposed in a substantially V-shape.

[0021] The second driven shaft 500 has a cylindrical sleeve 510 that is slidable in the axial direction of the second driven shaft 500 and rotates in conjunction with the second driven shaft 500. The second driven shaft 500 has a first selection gear 520 at one end of the sleeve 510 and a second selection gear 530 at the other end of the sleeve 510. That is, the first selection gear and the second selection gear are provided at ends of the sleeve 510 with a predetermined distance between them. The first selection gear 520 and the second selection gear 530 are configured integrally with the sleeve 510 and can therefore rotate together with the sleeve 510 and the second driven shaft 500.

[0022] The sleeve 510 can slide along the axial direction of the second driven shaft 500 by a rotation selection unit 600 formed of a lever. As a result, the sleeve 510 can be set at two positions, a first position or a second position, in the axial direction of the second driven shaft 500. When the sleeve 510 is set at the first position or the second position, the axial movement of the second driven shaft 500 is restricted, but the sleeve 510 can rotate in conjunction with the second driven shaft 500. The first selection gear 520 and the second selection gear 530 slide in the axial direction together with the sleeve 510 while maintaining a predetermined gap therebetween, and can be set at two positions, the first position or the second position. As a result, the sleeve 510 can function as a spacer that maintains a constant gap between the first selection gear 520 and the second selection gear 530.

[0023] The first selection gear 520 is a tapered bevel gear that narrows from one end to the other. The minimum diameter of the first selection gear 520 is larger than the maximum diameter of the driven gear 410. The first selection gear 520 is configured to mesh with a portion of the drive gear 310.

[0024] The second selection gear 530 is a tapered bevel gear that narrows from one end to the other. The pitch cone angle of the second selection gear 530 is the same as the pitch cone angle of the driven gear 410. The maximum diameter of the second selection gear 530 is smaller than the minimum diameter of the first selection gear 520. The second selection gear 530 is configured to mesh with the driven gear 410. Note that in the kneader 100 of this embodiment, the first screw 130 and the second screw 140 are conical screws, so the first driven shaft 400 and the second driven shaft 500 are arranged in a V-shape and each gear is a bevel gear. However, if the first screw 130 and the second screw 140 are parallel screws and the first driven shaft 400 and the second driven shaft 500 are arranged in parallel, spur gears may be used.

[0025] As described above, the rotation selecting unit 600 can slide the sleeve 510 along the axial direction of the second driven shaft 500. Fig. 3 is an exploded view of each shaft in the same direction rotation mode of the kneader 100, showing the arrangement relationship of each gear. In the kneader 100 of this embodiment, the first driven shaft 400 and the second driven shaft 500 are arranged in a substantially V-shape with the axial distance gradually decreasing toward the tip, but in Fig. 3, the first driven shaft 400 and the second driven shaft 500 are drawn parallel to each other for ease of explanation.

[0026] In the same-direction rotation mode, the sleeve 510 is slid in the axial direction of the second driven shaft 500 by the rotation selection unit 600 and set to the first position. As shown in the assembly diagram of Fig. 1 and by the two-dot chain line in Fig. 3, the driven gear 410 is engaged with the other end of the drive gear 310. Therefore, the driven gear 410 rotates in the opposite direction to the drive gear 310, and the first driven shaft 400 rotates in the same direction as the driven gear 410, with rotation transmitted from the driven gear 410.

[0027] Meanwhile, the first selection gear 520 is meshed with one end of the drive gear 310. Therefore, the first selection gear 520 rotates in the opposite direction to the drive gear 310, and the second driven shaft 500 receives rotation from the first selection gear 520 and rotates in the same direction as the first selection gear 520. That is, the first driven shaft 400 and the second driven shaft 500 rotate in the same direction, and the first screw 130 connected to the first driven shaft 400 and the second screw 140 connected to the second driven shaft 500 rotate in the same direction. The rotation speeds of the first driven shaft 400 and the second driven shaft 500 are the same, and the first screw 130 and the second screw 140 rotate at the same rotation speed. As a result, the first screw 130 and the second screw 140 can knead the viscous material with a constant clearance without interfering with each other within the barrel 110 and transport the viscous material to the barrel outlet 111. In the same direction rotation mode, the second selection gear 530 rotates together with the second driven shaft 500 without meshing with any other gear.

[0028] Fig. 4 is an exploded view of each shaft in the counter-rotation mode of the kneader 100, and Fig. 5 is a diagram showing the meshing relationship of each gear in the counter-rotation mode. Figs. 4 and 5 show the arrangement relationship of each gear. The sleeve 510 is slid in the axial direction of the second driven shaft 500 by the rotation selecting unit 600 and set to the second position. As in the same-direction rotation mode, the driven gear 410 is engaged with the drive gear 310, and the first driven shaft 400 receives rotation transmitted from the driven gear 410 and rotates in the same direction as the driven gear 410.

[0029] As shown by the two-dot chain line in Fig. 4, the first selection gear 520 does not overlap with the drive gear 310 at the second position of the sleeve 510, and is disengaged from the drive gear 310. On the other hand, as shown in Fig. 5, the second selection gear 530 is formed with a maximum diameter smaller than the minimum diameter of the first selection gear 520 provided on the same axis, and therefore is engaged with the driven gear 410 at a position where it does not engage with the drive gear 310 at the second position of the sleeve 510. Therefore, the second selection gear 530 rotates in the opposite direction to the rotation direction of the driven gear 410.

[0030] As a result, the second driven shaft 500 receives rotation from the second selection gear 530 and rotates in the same direction as the second selection gear 530. As a result, the driven gear 410 and the second selection gear 530 rotate in opposite directions, so that the first screw 130 connected to the first driven shaft 400 and the second screw 140 connected to the second driven shaft 500 rotate in opposite directions. The rotation speeds of the first driven shaft 400 and the second driven shaft 500 are the same, and the first screw 130 and the second screw 140 rotate at the same rotation speed. As a result, the first screw 130 and the second screw 140 do not interfere with each other within the barrel 110, and can knead the viscous material with reduced shear force compared to a unidirectional rotation mode, and transport the viscous material to the barrel outlet 111. In addition, the kneader 100 can switch between inward and outward rotation of the first screw 130 and the second screw 140 by changing the rotation direction of the motor 200.

[0031] Therefore, the rotation selecting unit 600 can set the sleeve 510 to either a first position or a second position, and can select either the meshing between the drive gear 310 and the first selection gear 520 or the meshing between the driven gear 410 and the second selection gear 530. As a result, the kneader 100 can arbitrarily change the rotation directions of the first screw 130 and the second screw 140 arranged in the barrel 110 between the same direction and the opposite directions. Note that the rotation selecting unit 600 is configured to be able to slide the sleeve 510, on which the first selection gear 520 and the second selection gear 530 are provided, in the axial direction of the second driven shaft 500, but may also be configured as levers that slide the first selection gear 520 and the second selection gear 530, respectively. Furthermore, the rotation selection unit 600 does not necessarily have to be configured as a lever, but may be configured in any way as long as it can select either the meshing between the drive gear 310 and the first selection gear 520 or the meshing between the driven gear 410 and the second selection gear 530.

[0032] As described above, the kneader 100 can rotate the first screw 130 and the second screw 140 in the barrel 110 in the same or opposite directions using a single motor for rotating the drive gear 310. Therefore, the kneader 100 can reduce the number of parts compared to conventional kneaders in which a motor is connected to each screw as a drive source and the direction of rotation of the motor is changed to switch between the same and opposite rotation directions of the screws, thereby achieving a more compact device. Furthermore, while the kneader 100 switches between the same and opposite rotation directions of the screws using shafts and gears, the kneader 100 can switch between the same rotation mode and the opposite rotation mode using only three shafts: the drive shaft 300, the first driven shaft 400, and the second driven shaft 500, which also contributes to a more compact device. Furthermore, the kneader 100 can easily switch between the same rotation mode and the opposite rotation mode by operating a rotation selection unit.

[0033] 6 and 7 are diagrams showing a second embodiment of the kneader 100. In the kneader 100, parallel screws are used as the first screw 130 and the second screw 140, and the first driven shaft 400 and the second driven shaft 500 are arranged in parallel. The driven gear 410, the first selection gear 520, and the second selection gear 530 are spur gears having the same pitch circle diameter and circular pitch. FIG. 6 is a diagram showing the meshing state of each gear in the same direction rotation mode of the kneader 100. In the same direction rotation mode, the drive gear 310 and the driven gear 410 mesh with each other to rotate the first driven shaft 400, while the drive gear 310 and the first selection gear 520 mesh with each other to rotate the second driven shaft 500. Therefore, the first driven shaft 400 and the second driven shaft 500 rotate in the same direction at the same rotation speed. The second selection gear 530 is not meshed with any gear.

[0034] 7 is a diagram showing the meshing state of each gear in the counter-rotation mode of the kneader 100. In the counter-rotation mode, the first driven shaft 400 rotates while the drive gear 310 meshes with the driven gear 410 in a first meshing region 420, which is a part of the axial region of the driven gear 410. On the other hand, the second driven shaft 500 rotates while the second selection gear 530 meshes with the driven gear 410 in a second meshing region 430, which is a part of the axial region of the driven gear 410. The first meshing region 420 and the second meshing region 430 do not overlap in the axial direction of the driven gear 410. Therefore, the drive gear 310 and the second selection gear 530 do not come into contact with each other during kneading in the counter-rotation mode. This allows the first driven shaft 400 and the second driven shaft 500 to rotate in different directions at the same rotation speed. The first selection gear 520 is not meshed with any gear. [Explanation of symbols]

[0035] 100... kneader, 110... barrel, 111... barrel outlet, 120... supply port, 130... first screw, 131... first kneading blade, 140... second screw, 141... second kneading blade, discharge port... 180, circulation flow path... 190, 200... motor, 300... drive shaft, 310... drive gear, 400... first driven shaft, 410... driven gear, 500... second driven shaft, 510... sleeve, 520... first selection gear, 530... second selection gear, 600... rotation selection unit

Claims

1. A kneader that kneads different types of viscous materials in a barrel having a kneading space formed therein for the viscous materials and conveys the viscous materials toward an outlet of the barrel, a drive shaft to which rotation of the motor is transmitted and to which a drive gear is provided; a first driven shaft provided with a driven gear that meshes with the drive gear; a second driven shaft provided with a first selection gear that meshes with the drive gear and a second selection gear that meshes with the driven gear, and to which rotation of the drive shaft is transmitted from either the first selection gear or the second selection gear; a first screw connected to one end of the first driven shaft and housed in the barrel, the first screw having a first kneading blade formed around its periphery; a second screw connected to one end of the second driven shaft and disposed adjacent to the first screw within the barrel, the second screw having a second kneading blade formed around its periphery and meshing with the first kneading blade; a rotation selection unit that can select either meshing between the drive gear and the first selection gear or meshing between the driven gear and the second selection gear; A kneading machine comprising:

2. the first driven shaft and the second driven shaft are arranged in a substantially V-shape such that the axis-to-axis distance gradually decreases toward the one end, the drive gear, the driven gear, the first selection gear, and the second selection gear are configured as tapered bevel gears narrowing from one end to the other end, 2. The kneader according to claim 1, wherein the first screw and the second screw have a conical shape that gradually narrows toward a tip.

3. 3. The kneader according to claim 2, wherein the maximum diameter of the second selection gear is smaller than the minimum diameter of the first selection gear.

4. the first selection gear and the second selection gear are provided at a predetermined interval on an end of a cylindrical sleeve that is slidable in the axial direction of the second driven shaft and rotates in conjunction with the second driven shaft, The kneader according to claim 3, characterized in that the rotation selection unit can select either meshing between the drive gear and the first selection gear or meshing between the driven gear and the second selection gear by operating the sleeve to move the first selection gear and the second selection gear simultaneously.

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