JP2009006607A - Extruder with gear pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extruder with a gear pump, in which a constant amount of the material to be discharged from the gear pump can be discharged surely just after the rotation of the gear pump is started. <P>SOLUTION: The extruder with the gear pump includes: the extruder for extruding the material consisting of rubber or plastics in a barrel, in the axial direction by rotating a screw arranged in the barrel; and the gear pump for discharging a constant amount of the extruded material by engaging gears with each other, wherein a drive pinion 4 of the gear pump 3 is rotary driven independently of the screw 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an extruder with a gear pump that measures and extrudes a predetermined amount of a material made of rubber or plastic, and more particularly, to an apparatus that can control the amount of rubber discharged quantitatively immediately after the gear pump is driven.

  Conventionally, an apparatus has been known in which a gear pump driven by the rotation of a screw is disposed downstream of an extruder in order to extrude a certain amount of rubber or plastic material (see, for example, Patent Document 1), and FIG. FIG. 1 is a conceptual diagram showing such an extruder with a gear pump. An extruder 90 with a gear pump is an extruder that extrudes a material made of rubber or plastic in a barrel 96 in the axial direction by the rotation of a screw 91 provided in the barrel. And a gear pump 99 that discharges the extruded material by a fixed amount by meshing the gear. The gear pump 99 is driven by meshing with the drive pinion 92 concentrically with the screw 91 and the drive pinion 92. And one or more driven pinions 93, and the material extruded by the extruder 98 is fed at a constant flow rate. It serves to eject gold opening 97.

The gear pump type extruder 90 configured as described above has a simple mechanical configuration as an extruder for extruding rubber or plastic in a fixed amount, and the screw 91 and the drive pinion 92 are driven by the same drive source. There is also a feature that the device can be manufactured at a low cost.
JP-A-2005-201215

  However, in the extruder 90 with a gear pump configured as described above, since the screw 91 and the drive pinion 92 are driven by the same drive source, when the screw 91 is rotated at a constant rotational speed, the gear pump In contrast to the amount of rubber discharged by 99 being fixed at a fixed amount determined by the gear tooth size, the amount of rubber pushed out by the screw 91 slightly changes depending on the viscoelastic characteristics of the extruded rubber. Therefore, the flow rate of the rubber pushed out from the screw 91 into the gear pump 99 changes. This means that the amount of rubber filling in the gear pump 99 changes, and as a result, even if the gear pump is rotated at a constant speed, it becomes difficult to stably discharge the rubber discharge amount. Immediately after the gear pump 99 is operated, since the filling rate of the rubber in the gear pump 99 is low, a device capable of discharging at a constant rubber flow rate immediately after the start of the rotation of the gear pump 99 has been demanded.

  The present invention has been made in view of such problems, and is equipped with a gear pump capable of discharging a material made of rubber or plastic discharged by a gear pump at a constant discharge amount immediately after the start of rotation. An object is to provide an extruder.

<1> is a method in which a screw or a screw provided in the barrel rotates to extrude a material made of rubber or plastic in the barrel in the axial direction, and the extruded material is discharged in a fixed amount by meshing the gear. The gear pump includes a drive pinion, one or more driven pinions that are driven by meshing with the drive pinion, and a gear pump extrusion provided with a gear case that is fixed to the barrel and accommodates these pinions. In the machine
The drive pinion is an extruder with a gear pump configured to be driven to rotate independently of the screw.

<2> is the side plate according to <1>, wherein the gear case is disposed on both sides in the axial direction of the drive pinion and the driven pinion via a minute gap and extends perpendicular to the drive pinion rotation axis; The casing is provided between the side plates and closes the space outside the pinion in the radial direction.
The rotating shafts of the driving pinion and the driven pinion are fixed to the side plate,
Among the side plates, the suction side side plate located on the side closer to the screw has a rubber suction port of the driven pinion on the side where the teeth of the driving pinion and each driven pinion are separated from each other. The discharge side plate, which is provided at the position where the teeth pass and is located on the side far from the screw, has a rubber discharge port on the side where the teeth approach each other in the meshing portion of the drive pinion and each driven pinion, The extruder with a gear pump is provided at a position where the teeth of the driven pinion pass, and the rubber suction port and the rubber discharge port are blocked from communicating in the axial direction by the pinion.

  <3> is an extruder with a gear pump in which the gears of the drive pinion and the driven pinion are formed in a helical tooth in <1> or <2>.

  <4> is any one of <1> to <3>, on the suction side plate and on the discharge side of the rubber suction port and the rubber discharge port on the side close to the meshing portion between the drive pinion and each driven pinion Each of the extruders with gear pumps is provided with a recess for preventing material biting on the plate.

  <5> is an extruder with a gear pump in which a cooling jacket is provided on the casing in any one of <1> to <4>.

  <6> includes a control device that controls the rotation of the screw and the drive pinion in any one of <1> to <5>, and the control device is connected to the screw before the rotation of the drive pinion starts. An extruder with a gear pump configured to perform control for starting rotation.

  According to <1>, since the drive pinion is configured to be driven to rotate independently of the screw, rotation control of the screw and the gear pump can be performed independently, that is, in the gear pump. It can be controlled to be always filled with rubber, and can be controlled to extrude a certain amount of rubber immediately after the start of rotation of the gear pump.

  According to <2>, the teeth of the driven pinion on the side where the teeth of the driving pinion and each driven pinion are separated from each other pass through the suction side side plate located on the side closer to the screw. The discharge side plate, which is provided with a rubber suction port at a position far from the screw, has a tooth of the driven pinion on the side where the teeth of the driving pinion and each driven pinion come into contact with each other. A rubber discharge port is provided at a position where the valve passes, and the rubber suction port and the rubber discharge port are blocked from communicating in the axial direction by a pinion, so that the material extruded in the axial direction from the tip of the screw is driven In the vicinity of the meshing part between the pinion and the driven pinion, the drive pinion central axis is once moved away from the drive pinion central axis while entering the valley between the teeth of the driven pinion. Is re-approached and discharged near the meshing portion of the drive pinion and the driven pinion, so that the rubber material does not flow between the teeth of the drive pinion, and if the drive pinion is In the case of driving through the meshing drive gear, this problem can be solved where rubber that has entered between the teeth of the drive pinion should hinder smooth power transmission to the drive pinion.

  According to <3>, since the gears of the drive pinion and the driven pinion are formed on the helical teeth, a force of a component that directs the material toward the tip end in the axial direction can be generated during the rotation thereof. Ejection can be performed efficiently.

  <4> According to <4>, on the suction side plate and the discharge side plate on the side close to the meshing portion between the drive pinion and each driven pinion of the rubber suction port and the rubber discharge port, respectively, prevention of material biting Since the concave part is provided, it is possible to prevent the material from leaking into the meshing part and forcibly deforming each pinion, and also prevents the material from leaking from the suction side to the discharge side. Can be increased.

  According to <5>, since the cooling jacket is provided in the casing, it is possible to prevent an abnormal temperature rise of the material and to suppress deterioration of the material such as rubber burn.

  According to <6>, the control device that controls the rotation of the screw and the drive pinion is provided, and the control device is configured to perform the control to start the rotation of the screw prior to the start of the rotation of the drive pinion. Therefore, the gear pump can be filled with rubber from the start of rotation of the drive pinion, and as a result, the amount of discharged rubber can be controlled to be constant immediately after the start of discharging of rubber from the gear pump. .

  Embodiments of the present invention will be described with reference to the drawings. 2 is a schematic diagram schematically showing the configuration of the extruder with a gear pump of this embodiment. FIG. 3 is a partial sectional view showing the gear pump portion in a cross section passing through the rotation axis. FIG. FIG. 5 is a perspective view showing a pinion portion, FIG. 6 is a perspective view showing each side plate, FIG. 7 is a perspective view showing a casing, and FIG. 8 is provided on the side plate. It is a perspective view which shows the position of the formed opening part and recessed part corresponding to a pinion. In the following description, the material to be extruded will be described as rubber, but the description can be applied as it is even if it is plastic.

  The extruder 1 with a gear pump is provided in the barrel 22, and the rubber G supplied from the rubber feed port 27 by the feed roller 28 is spirally pushed out in the axial direction by the rotation of the screw 21 driven by the screw driving unit 31. The extruder 2 and the screw drive unit 31 are driven by a gear pump drive unit 41 that constitutes a drive mechanism independent of the screw drive unit 31, and a gear pump 3 that discharges the extruded rubber G with a constant mesh by meshing the gears.

  The gear pump 3 is fixed to the barrel 22 and a drive pinion 4, one or more driven pinions 5 that are driven by meshing with the drive pinion 4, and rotate about an axis parallel to the drive pinion rotation axis L. A gear case 11 for accommodating these pinions 4 and 5 is provided.

  The screw 21 is driven by a screw drive unit 31. The screw drive unit 31, as illustrated in FIG. 2, includes a screw drive motor 32, a screw drive speed reducer 33 that increases the drive torque by shifting the output of the screw drive unit 31, The screw driving force transmission chain 34 that transmits the rotation output to the screw 21 and the driving side sprocket 35A and the driven side sprocket 35B that mesh with the chain 21 are configured. However, the screw driving unit in the present invention is limited to this configuration. It is not something.

  On the other hand, the drive pinion 4 is driven by a gear pump drive unit 41. The gear pump drive unit 41, for example, as shown in FIG. 2, a gear pump drive motor 42 and a gear pump drive deceleration that shifts its output and increases the drive torque. The machine 43, a gear pump driving force transmission chain 44 for transmitting the rotational output to the screw 21, a driving side sprocket 45A and a driven side sprocket 45B meshing with the chain, and a driven side sprocket 45B arranged coaxially are directly connected. In addition, the driving force transmission gear 46 that meshes with the driving pinion 4 is configured, but the gear pump driving unit in the present invention is not limited to this configuration.

  Further, in order to control the rotational speeds of the screw 21 and the gear pump 3, the rotational speeds of the screw driving motor 32 and the gear pump driving motor 42 for driving these are controlled respectively. The rotation control is controlled based on a command from the control device 50 that controls these rotations.

  The gear case 11 is disposed on both sides in the axial direction of the pinions 4 and 5 via a minute gap and extends perpendicularly to the rotational axis L of the drive pinion 4, and these side plates 12 and 13 The casing 14 is provided between the side plates 12 and 13 and closes the radially outer space of the pinions 4 and 5. The rotating shaft 15 of the driving pinion 4 and the rotating shaft 16 of the driven pinion 5 are connected to the side plates 12 and 13. 13, and the suction side side plate 12 located on the side close to the screw 21 among the side plates 12, 13 has mutual engagement portions of the drive pinion 4 and each driven pinion 5. A rubber suction port 12a is provided at a position where the teeth of the driven pinion 5 pass on the side where the teeth are separated from each other, and is positioned on the side far from the screw 21 The discharge-side side plate 13 is provided with a rubber discharge port 13a at a position where the teeth of the driven pinion 5 pass on the side where the teeth of the drive pinion 4 and each driven pinion 5 are close to each other. The rubber suction port 12a and the rubber discharge port 13a are configured to be blocked from communicating in the axial direction by pinions 4 and 5.

  A head 24 having a base opening 25 is attached to the discharge side plate 13 on the side far from the screw 21, and a rubber flow chamber 26 is formed between the discharge side plate 13 and the discharge side plate 13.

  In the extruder 1 with a gear pump configured as described above, the rubber G pushed to the axial front end side by the rotation of the screw 21 enters the gear case 11 through the suction port 12a of the suction side plate 12, The driven pinion 5 is pushed into the valley between the teeth. The rubber G pushed into the valley portion is once transported in a direction away from the drive pinion 4 along with the rotation of the driven pinion 5 and is turned back through the radially outermost side of the gear case 11. When the driven pinion 5 reaches a position where the driven pinion 5 starts to mesh with the drive pinion 4, the rubber G is scraped out from the valley portion by the meshing action, and the rubber G thus scraped out passes through the discharge port 13a to the gear. It exits from the case 11 and enters the rubber flow chamber 26 and is extruded through the mouth opening 25 with a predetermined cross-sectional shape.

  Here, the rubber G is pushed between the teeth of the driven pinion 5 and not between the teeth of the drive pinion 4 but moved between the teeth of the driven pinion 4, as shown in the figure, meshes with the drive pinion 4. If the driving force is transmitted via the driving force transmission gear 46, it is a necessary requirement, and if it enters between the teeth of the driving pinion 4, smooth driving is impeded. In addition, it is necessary to take measures to prevent rubber leakage in the drive system.

  Here, a cutout for smoothly passing the rubber G is provided in the casing 14 at a position facing the suction port 12a and the discharge port 12b provided in each of the side plates 12 and 13, and reference numeral 14a in FIG. Represents this notch. FIG. 8A is a perspective view showing the positions of the suction port 12a provided in the suction side plate 12 and the recess for preventing biting in correspondence with the pinion. In the figure, 12a1 is the suction port 12a. Reference numeral 12b1 denotes a portion corresponding to the biting prevention concave portion. Similarly, FIG. 8B is a perspective view showing the positions of the discharge ports 13a provided in the discharge-side side plate 13 and the recesses for preventing biting corresponding to the pinions. In FIG. A portion corresponding to the discharge port 13a, 12b1, indicates a portion corresponding to the biting prevention concave portion.

The teeth of the drive pinion 4 and the driven pinion are preferably helical teeth, which allows the rubber G to be sucked and discharged efficiently.

  Further, cooling jackets 19 for cooling the heat generated with the flow of the rubber G are respectively arranged on the radially outer sides of the barrel 22 and the casing 14, and these cooling jackets 19 are connected in parallel or in series. Can do.

  In the extruder 1 with a gear pump configured as described above, the screw 21 and the gear pump 3 are independently driven. Therefore, when the gear pump 3 is driven by starting the screw 21 before the gear pump 3, Can be made to be filled with rubber, and this will push out the rubber amount at a constant flow rate immediately after the start of gear pump drive without being affected by the viscoelasticity of the rubber, which varies with the external environment such as temperature. be able to.

  When the rubber ribbon extruded from the extruder with gear pump is wound on a tire molding drum and the rubber member is pasted on the already formed tire constituent member, every time the rubber member for one tire is formed, In addition, since the drive of the extruder with gear pump is started or stopped, the ratio of the time immediately after the drive to the total extrusion time is large, and the function of pushing out the rubber amount at a constant flow rate immediately after the start of the gear pump drive is particularly important. It is.

  In addition, if the screw extrusion capacity and the gear pump discharge capacity are in conflict, this means that even if the screw extrusion amount decreases slightly, the gear pump discharge amount will decrease. Since the amount of time fluctuation is generated and the size of the extruded rubber product is varied, it is necessary to control the extrusion ability of the screw to always exceed the discharge ability of the rubber.

  However, in reality, the extrusion capability of the screw changes due to the viscoelastic properties of the rubber. If the ratio of the screw rotation speed to the gear pump rotation speed is fixed as in the prior art, the rubber Although it is difficult to satisfy this condition depending on the type, in the present invention, the rotational speeds of the screw and the gear pump can be selected independently of each other, so the above condition is satisfied regardless of the rubber type. You can set the rotation speed of them.

  Specifically, in order to control the rotation speed and the drive start timing, the control device 50 is used. From the control device 50, the screw drive motor 32 and the gear pump drive motor 42 transfer the rotation speed and the drive start timing. This can be done by outputting a signal for controlling the timing for starting driving.

  FIG. 11 is a graph showing a change in the amount of rubber discharged from the gear pump 3 immediately after the gear pump 3 is driven, and a curve A is a discharge when driven by the extruder with a gear pump of this embodiment as an example. On the other hand, the curve B represents the change in the discharge amount when the drive pinion 4 is directly connected to the screw 21 and the drive pinion 4 is driven by the same drive system as the screw as a conventional example. As is apparent from the figure, the conventional example requires a long time to reach the predetermined discharge amount, whereas the curve B corresponding to the present embodiment is half the time immediately after driving. This indicates that a predetermined discharge amount can be reached.

  The screw head pressure (discharge side pressure) at the start of the gear pump drive is 3.3 MPa in the conventional example, whereas it is 10 MPa in the example. In this case, it can be seen that the gear pump was already filled with sufficient rubber at the start of driving the gear pump.

  The rubber gear extruder of the present invention can be applied to extrude a rubber band of rubber constituting members for various tires.

It is sectional drawing which shows the structure of the conventional extruder with a gear pump. It is a schematic diagram which shows the structure of the extruder with a gear pump of embodiment which concerns on this invention. It is a fragmentary sectional view which shows the extruder with a gear pump of embodiment which concerns on this invention in the plane which passes along a screw rotating shaft line. It is a fragmentary sectional view corresponding to the AA arrow of FIG. It is a perspective view which shows a pinion part. It is a perspective view which shows each side plate. It is a perspective view which shows a casing. It is a perspective view which shows the position of the opening part provided on the side plate, and a recessed part corresponding to a pinion. It is a graph which shows the change of the amount of rubber discharge immediately after the drive of a gear pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder with gear pump 2 Extruder 3 Gear pump 4 Drive pinion 5 Driven pinion 11 Gear case 12 Suction side plate 12a Suction port 12a1 Pinion part corresponding to suction port 12b1 Pinion part corresponding to biting prevention recess 13 Discharge side plate 13a Discharge port 13a Pinion portion corresponding to discharge port 13b1 Pinion portion corresponding to biting prevention recess 14 Casing 14a Notch on casing 15 Rotating shaft of driving pinion 16 Rotating shaft of driven pinion 4 19 Cooling jacket 21 Screw 22 Barrel 24 Head 25 Base opening 26 Rubber flow chamber 27 Rubber feed port 28 Feed roller 31 Screw drive portion 32 Screw drive motor 33 Screw drive speed reducer 34 Screw drive force transmission chain 3 A drive sprocket 35B driven sprocket 41 gear pump drive unit 42 gear pump drive motor 43 gear pump drive speed reducer 44 a gear pump driving force transmission chain 45A driven sprocket 45B driven sprocket 46 driving force transmission gears

Claims (6)

An extruder for extruding a material made of rubber or plastic in the barrel in the axial direction by rotation of a screw provided in the barrel, and a gear pump for discharging the extruded material in a constant amount by meshing the gears, The gear pump is an extruder with a gear pump comprising a drive pinion, one or more driven pinions that are engaged with and driven by the drive pinion, and a gear case that is fixed to the barrel and accommodates these pinions.
An extruder with a gear pump configured to rotate the drive pinion independently of the screw. Each of the gear cases is disposed on both sides in the axial direction of the drive pinion and the driven pinion via a minute gap and extends in a direction perpendicular to the drive pinion rotation shaft, and the pinion provided between the side plates. And a casing that closes the radially outer space of
The rotating shafts of the driving pinion and the driven pinion are fixed to the side plate,
Among the side plates, the suction side side plate located on the side closer to the screw has a rubber suction port of the driven pinion on the side where the teeth of the driving pinion and each driven pinion are separated from each other. The discharge side plate, which is provided at the position where the teeth pass and is located on the side far from the screw, has a rubber discharge port on the side where the teeth approach each other in the meshing portion of the drive pinion and each driven pinion, The extruder with a gear pump according to claim 1, wherein the extruder is provided at a position through which the teeth of the driven pinion pass, and the rubber suction port and the rubber discharge port are blocked from communicating in the axial direction by the pinion.   The extruder with a gear pump according to claim 1 or 2, wherein the gears of the drive pinion and the driven pinion are formed in a helical tooth.   The rubber suction port and the rubber discharge port are respectively provided with recesses for preventing material biting on the suction side plate and the discharge side plate on the side close to the meshing portion between the drive pinion and each driven pinion. Item 4. An extruder with a gear pump according to any one of Items 1 to 3.   The extruder with a gear pump according to any one of claims 1 to 4, wherein the casing is provided with a cooling jacket.   6. A control device for controlling the rotation of the screw and the drive pinion is provided, and the control device is configured to perform a control for starting the rotation of the screw prior to the start of the rotation of the drive pinion. The extruder with a gear pump in any one of.