JP2006103199A - Gear pump extruder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gear pump extruder which is small-sized and capable of stably extruding materials. <P>SOLUTION: A gear pump extruder 1 has a casing 2 having a feed port I and an extrusion port O for a material m and a pair of extrusion gears 3 and 4 which are arranged in the casing 2, are meshed with each other and driven by a first driving means and sends the material m from the feed port I side to the extrusion port O side through the clearance between the inner circumference surface 8a of the casing 2 and the tooth grooves of the extrusion gears 3 and 4. In the casing 2 and between the extrusion gears 3 and 4 and the feed port I, a pair of feed gears 5 and 6 are arranged which feed the material m supplied from the feed port I to the extrusion gears 3 and 4. Each of the feed gears 5 and 6 is arranged apart from the extrusion gears 3 and 4 without being meshed with the extrusion gears 3 and 4 and rotationally driven by a second driving means different from the first driving means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gear pump extruder that can be miniaturized and can stably extrude materials.

  Conventionally, a gear pump extruder that extrudes unvulcanized rubber or a similar plastic material is known. For example, as schematically shown in FIG. 7, the gear pump extruder a includes a gear pump part b and a material supply part c. The gear pump part b includes a casing d having a material supply port i and an extrusion port o, and a pair of extrusion gears G1 and G2 disposed inside the casing d and meshing with each other. An extrusion head e having a predetermined cross-sectional shape is usually attached to the extrusion port o of the gear pump part b.

  Moreover, since the gear pump part b does not have a mechanism for supplying the material to itself, the gear pump part b alone cannot stably extrude the material. For this reason, a screw type extruder is generally used as the material supply unit c. The discharge port co of the screw type extruder is connected to the supply port i of the gear pump part b. The prior art includes the following.

JP 2004-82527 A JP 2004-175103 A

  Such a gear pump extruder a can fill the material supplied from the material supply part c to the gear pump part b between the casing d and the tooth gaps of the extrusion gears G1 and G2 and transfer the material to the extrusion port o. The transferred material is extruded through the extrusion head e with a predetermined cross-sectional shape.

  However, as is apparent from FIG. 7, the gear pump extruder a as described above has the disadvantages that the apparatus becomes large and the equipment cost is high.

  The present invention has been devised in view of the above circumstances, and an object thereof is to provide a gear pump extruder that can be easily downsized and can stably extrude a material.

  The invention according to claim 1 of the present invention is a casing having a material supply port and an extrusion port, and a pair of extrusion gears arranged inside the casing and meshing with each other and driven by a first driving means. A gear pump extruder that feeds material from the supply port side to the extrusion port side between the inner peripheral surface of the casing and the tooth groove of each extrusion gear, the interior of the casing and the extrusion gear A pair of feed gears for supplying the material charged from the supply port to the extrusion gear side is provided between the supply port and the supply port, and each feed gear is provided so as not to mesh with any of the extrusion gears. In addition, at least one of the feed gears is rotationally driven by a second driving unit different from the first driving unit.

  The invention according to claim 2 is the gear pump extruder according to claim 1, wherein the feed gear forms a material reservoir portion between the feed gear and the extrusion gear.

  According to a third aspect of the present invention, the volume of the material reservoir is 4 to 7 times the sum of the tooth space of the pair of push gears and the pair of feed gears. This is a gear pump extruder.

  According to a fourth aspect of the present invention, the pressure detector that detects the pressure on the downstream side of the extrusion gear, and the second driving means is driven based on the detection signal of the pressure detector to preset the pressure. The gear pump extruder according to any one of claims 1 to 3, further comprising a control device that controls to a certain range.

  According to a fifth aspect of the present invention, the feed gear includes a gear portion and a roller portion that is provided adjacent to the rotation axis direction of the gear portion and has a diameter smaller than the diameter of the tip of the gear portion. The first feed gear and the second feed gear that are integrally formed, and the gear portion of the first feed gear is the roller portion of the second feed gear, and the roller portion of the first feed gear is the second feed gear. The gear pump extruder according to any one of claims 1 to 4, wherein a gap is formed so as to face each of the gear portions of the feed gear and allow the material to pass between the gear portion and the roller portion. is there.

  According to a sixth aspect of the present invention, the feed gear includes a first feed gear and a second feed gear that are spaced apart from each other without being meshed with each other, and between the first feed gear and the second feed gear. The gear pump extruder according to any one of claims 1 to 4, wherein a gap through which material can pass is formed.

  The gear pump extruder of the present invention is provided with a pair of feed gears for supplying the material charged from the supply port to the extrusion gear side inside the casing and between the extrusion gear and the supply port. Each feed gear is provided so as not to mesh with any of the extrusion gears and spaced from the extrusion gear, and at least one of the feed gears is rotated by a second driving means different from the first driving means for driving the extrusion gear. Driven.

  Therefore, the gear pump extruder according to the present invention can continuously supply the material to the extrusion gear without providing an external material supply means such as a screw type extruder. Therefore, the apparatus can be reduced in size and cost. Further, since the feed gear is driven by the second driving means different from the first driving means for driving the extrusion gear, the supply amount of the material to the extrusion gear can be freely controlled. This helps to allow stable material extrusion.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an overall plan view of a gear pump extruder showing an embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view taken along line AA of FIG.

  The gear pump extruder 1 of the present embodiment includes a casing 2 having a material supply port I and an extrusion port O, a pair of extrusion gears 3 and 4 that are arranged inside the casing 2 and mesh with each other, and an interior of the casing 2. And a pair of feed gears 5 and 6 that are provided between the extrusion gears 3 and 4 and the supply port I and supply the material charged from the supply port I to the extrusion gears 3 and 4 side. The The gear pump extruder 1 of the present embodiment is suitable for a material having viscosity and plasticity such as unvulcanized rubber or the like, but is not limited thereto and can be used for various materials. .

  The casing 2 has a rectangular parallelepiped shape, for example, and is fixed to the base B in this embodiment. However, the shape of the casing 2 can be arbitrarily configured. The casing 2 is provided with a material supply port I whose opening shape is substantially rectangular on one end surface side in the horizontal direction, and faces the supply port I and pushes out the material on the other end surface side in the horizontal direction. Extrusion port O is provided. The supply port I and the extrusion port O communicate with each other via a cavity 8 provided in the casing 2. Although not shown, a sheet-like material m is continuously fed into the supply port I from, for example, a calendar. Further, a die having a predetermined cross-sectional shape, an extrusion head having a die plate, and the like are appropriately attached to the extrusion port O. Thereby, the material m is continuously extruded with a predetermined cross-sectional shape (profile).

  4 shows a cross-sectional view taken along the line BB of FIG. 3 (however, the gear and the shaft are not shown in cross section). Extrusion gears 3 and 4 of this embodiment are arranged up and down in a meshing state. In this example, the pushing gears 3 and 4 are exemplified by helical gears, but it goes without saying that spur gears or helical gears may be used.

  The rotation shafts 9 and 10 of the extrusion gears 3 and 4 are substantially horizontal and are arranged in a direction perpendicular to the flow direction of the material m connecting the supply port I and the extrusion port O. . As is clear from FIGS. 1 and 2, in the present embodiment, the first driving means M <b> 1 is linked to the rotary shaft 10 of the lower extrusion gear 4. The first driving means M1 is composed of an electric motor fixed to the base B, for example. The drive torque of the electric motor is transmitted to the rotary shaft 10 directly or via a speed reducer or the like, and in this embodiment, the lower pushing gear 4 can be rotated clockwise in FIG. In addition, the rotating shaft 9 of the upper pushing gear 3 is rotatably supported in the casing 2. For this reason, the upper extrusion gear 3 can rotate counterclockwise by meshing with the lower extrusion gear 4.

  The feed gear includes two feed shafts 11 and 12 arranged in parallel inside the casing 2, and in the present embodiment, the first feed gear 5 arranged on the upper side and the lower side thereof. The second feed gear 6 is arranged. Each of the rotation shafts 11 and 12 is substantially parallel to the rotation shafts 9 and 10 of the extrusion gears 3 and 4, and both are rotatably supported inside the casing 2.

  The first feed gear 5 and the second feed gear 6 are arranged apart from the push gears 3 and 4 without meshing with any of the push gears 3 and 4. Further, as shown in FIGS. 1 and 2, the second driving means M2 is linked to the rotating shaft 12 of the second feed gear 6 disposed on the lower side. The second driving means M2 is composed of an electric motor fixed to the base B, for example. That is, the second driving unit M2 is configured by a device different from the first driving unit M1. Further, the driving torque of the second driving means M2 is transmitted to the rotating shaft 12 directly or via a reduction gear or the like, and the second feed gear 6 is rotated counterclockwise in FIG. 3 in this embodiment. Therefore, the rotation speed of the second feed gear 6 can be controlled regardless of the pushing gears 3 and 4.

  As shown in FIGS. 2 and 5, the rotary shafts 11 and 12 protrude outward from the casing 2, and a first gear G1 and a second gear G2 are fixedly engaged with each other. . Therefore, the first feed gear 5 can be rotated in the opposite direction, that is, clockwise by the counterclockwise rotation of the second feed gear 6.

  FIG. 5 is a cross-sectional view taken along the line CC in FIG. 3 (however, the gear and the shaft are not in cross section). The first feed gear 5 of the present embodiment includes a gear portion 5G having teeth arranged on the outer peripheral surface thereof, and is provided adjacent to the rotational axis direction of the gear portion 5G and is larger than the diameter of the tip of the gear portion 5G. A roller part 5R having a small diameter is integrally provided on the same axis. The second feed gear 6 also has a gear portion 6G with teeth connected to the outer peripheral surface, a diameter provided adjacent to the rotation axis direction of the gear portion 6G, and a diameter smaller than the tip diameter of the gear portion 6G. The roller portion 6R is integrally provided on the same axis. Note that the term “integral” is sufficient to be able to rotate at the same time, and does not mean that the gear portion and the roller portion are physically integrally formed.

  Further, in the present embodiment, the gear portions 5G and 6G of the first and second feed gears 5 and 6 are configured by the same helical gear. However, it is not limited to this, For example, other than this, a spur gear, a spur gear, etc. can also be used. The roller portions 5R and 6R of the first feed gear 5 and the second feed gear 6 also have substantially the same diameter, and the axial width thereof is the same as the width of the gear portions 5G and 5R. It is formed substantially equally.

  The gear portion 5G of the first feed gear 5 is connected to the roller portion 6R of the second feed gear 6, and the roller portion 5R of the first feed gear 5 is connected to the gear portion 6G of the second feed gear 6. They are arranged to face each other. In addition, a gap 13L through which the material m can pass between the gear portion 5G of the first feed gear 5 and the roller portion 6R of the second feed gear 6 is similarly a roller of the first feed gear 5. A gap 13R through which material can pass is formed between the portion 5R and the gear portion 6G of the second feed gear 6. That is, the first feed gear 5 and the second feed gear 6 are not directly meshed with each other.

  In the present embodiment, the first feed gear 5 and the second feed gear 6 are arranged so that the pitch circles of the gear portions 5G and the gear portions 6G are substantially in contact with each other when viewed from the axial direction. Therefore, as shown in FIG. 5, the gaps 13L and 13R are provided in a stepped manner without being continuous in the axial direction.

  Further, as shown in FIG. 3, the cavity 8 of the casing 2 includes a first inner peripheral surface 8a of a circular arc surface that is in sliding contact with the tooth tips of the rotating push gears 3 and 4, and each gear portion 5G of the feed gear. , 6G includes a second inner peripheral surface 8b of a circular arc surface with which the tooth tip surface is slidably contacted, and a joint surface 8c connecting between the first inner peripheral surface 8a and the second inner peripheral surface 8b. . The side surface of the cavity is constituted by a vertical surface equal to the width of each gear. One end of the first inner peripheral surface 8a is connected to the extrusion port O, and one end of the second inner peripheral surface 8b is connected to the insertion port I.

  The joint surface 8c is provided without slidingly contacting any of the push gear and the feed gear. In the next surface 8c of this embodiment, the vertical separation distance gradually increases from the charging port I side to the extrusion port O side, so that most of the tooth grooves of the extrusion gears 3 and 4 face the material reservoir Y. be able to. This serves to increase the material extrusion efficiency by the extrusion gears 3 and 4.

Next, the operation of the gear pump extruder 1 configured as described above will be described.
As indicated by phantom lines in FIG. 3, the material m made of unvulcanized rubber is continuously supplied to the input port I in the form of a sheet from a calendar machine or the like in this embodiment. The feed gears 5 and 6 are rotationally driven in the clockwise and counterclockwise directions in FIG. 3 by the second driving means M2, respectively, and are pulled into the gaps 13L and 13R while the material m is deformed by the gear portions 5G and 6G. . Depending on the shape of the material m, when the material m has a width dimension substantially equal to the inlet I, the material m is sheared by the gear portions 5G and 6G when passing through the gaps 13L and 13R, and the width Divided into two in the direction.

  The material m is pressed between the roller portion 5R (or 6R) and the gear portion 5G (or 6G) facing each other when passing through the gaps 13L and 13R. In particular, in the material m, a large number of notches (concave portions) in the direction intersecting with the feeding direction are formed or divided by the teeth of the gear portions 5G and 6G. Thereby, the bulk material m can be plasticized or fluidized more suitably and fed to the material reservoir Y. For this reason, the material can be continuously supplied to the extrusion gears 3 and 4 by the feed gear provided inside the casing 2 without providing a material supply means such as a screw-type extruder outside. Helps to reduce costs.

  Further, such a plastic state of the material m can be further optimized by controlling the average thickness T of the material m to be input and the minimum thickness t of the gap 13 in association with each other. As an example, the thickness ratio (t / T) is preferably 0.3 or more, more preferably 0.5 or more, and the upper limit is preferably 0.7 or less, more preferably 0.6 or less. When the desired ratio (t / T) is less than 0.3, the extrusion efficiency due to the supply interruption of the material is reduced and excessive heat generation due to friction tends to occur. As a result, the extrusion efficiency of the material by the extrusion gears 3 and 4 tends to decrease. The thickness t of the gap 13 can be determined as the shortest distance between the pitch circle of the gear portion 5G (or 6G) and the outer diameter of the roller portion 5R (or 6R), as shown in FIG. .

  In the present embodiment, a fan-shaped bush 15 is interposed between the second inner peripheral surface 8b and the roller portions 5R and 6R. Since the roller portions 5R and 6R have a smaller diameter than the gear portions 5G and 6G, a continuous gap is generated between the roller portions 5R and 6R and the second inner peripheral surface 8b. For this reason, the material m may cause a pressure drop in the material reservoir Y and a material return to the inlet I side. By providing the bush 15, the bush 15 is in sliding contact with the outer peripheral surfaces of the roller portions 5 </ b> R and 6 </ b> R, and the material m can be prevented from returning from the material reservoir Y to the inlet I side. Instead of such a bush, the inner peripheral surface of the cavity 8 of the casing 2 may be formed in a stepped manner in accordance with the roller portions 5R and 6R.

  The material m sent to the material reservoir Y by the feed gears 5 and 6 is transferred to the extrusion port O by a gear pump action by the extrusion gears 3 and 4. That is, the material m is filled between the first inner peripheral surface 8a and the tooth grooves of the respective extrusion gears 3 and 4, and is sequentially fed to the extrusion port O. Further, the reverse flow of the material m from the extrusion port O side to the supply port I side is prevented by the meshing portions of the extrusion gears 3 and 4.

  Since the first and second feed gears 5, 6 are arranged without meshing with the extrusion gears 3, 4, the feed gear 6 is connected to the extrusion gears 3, 4 in a series of material extrusion processes as described above. It can be controlled independently of the control. For example, when the amount of rubber to be extruded is excessive or insufficient, the amount of rubber to be extruded can be optimized by increasing or decreasing the rotation speed of the feed gear 6 while rotating the extrusion gears 3 and 4 at a constant speed.

  Further, in the gear pump extruder 1 of the present embodiment, the material reservoir Y having a relatively large volume can be formed between the feed gears 5 and 6 and the extrusion gears 3 and 4. The material reservoir Y can temporarily stock the material sent from the feed gears 5 and 6 until it is conveyed by the extrusion gears 3 and 4. This can prevent the extrusion material m from being insufficient.

  If the feed gears 5 and 6 are directly engaged with the extrusion gears 3 and 4, not only the rotation speed of the feed gears 5 and 6 can be controlled independently of the extrusion gears 3 and 4, but also the volume is sufficient. The material reservoir Y cannot be formed. For this reason, since the material sent from the feed gears 5 and 6 is transferred as it is by the extrusion gears 3 and 4, if the supply amount varies as much as possible, the extrusion amount of the material is likely to vary. The quality of the product is likely to deteriorate. On the other hand, when the material reservoir portion Y having a large volume as in the present embodiment is provided, a sufficient amount of material is temporarily stocked and the material can be stably supplied to the extrusion gears 3 and 4 at all times. Temporary fluctuations in the supply amount can be absorbed to stabilize the extrusion amount, thereby improving the quality of the extruded product.

  Here, the volume of the material reservoir Y is preferably 4 times or more, more preferably 6 times or more of the sum of the tooth space of the pair of push gears 3 and 4 and the pair of feed gears 5 and 6, and the upper limit. About 7 times or less is desirable. If the volume of the material reservoir Y is less than 4 times the sum of the tooth gap volumes, the amount of extrusion by the extrusion gears 3 and 4 is likely to vary. Conversely, if the volume exceeds 7 times, the casing 2 becomes larger, The material tends to stagnate for a long time in the material reservoir Y, and there is a tendency to cause rubber burning due to temperature rise.

  The total sum of the tooth gap volumes is the sum of the tooth gap volumes of the gears 3, 4, 5 and 6. The tooth gap volume can be calculated by closing the outer peripheral surface of the tooth gap with a virtual cylinder having a diameter equal to the tooth tip circle of each gear. The material reservoir Y is surrounded by the joint surface 8c of the casing 2, the extrusion gears 3 and 4, and the feed gears 5 and 6, but the gap between the feed gears 5 and 6 is not closed. The volume of the rotary shafts 11 and 12 is determined as being closed on a plane P1 including two axial center lines.

  FIG. 6 illustrates a cross-sectional view of a gear pump extruder 1 according to another embodiment of the present invention. In this embodiment, the 1st feed gear 5 and the 2nd feed gear 6 are illustrated in which they are largely separated from each other in the vertical direction. Such a gear pump extruder 1 is particularly suitable when the thickness T of the material m to be charged is large. Further, each of the first and second feed gears 5 and 6 is constituted only by a gear portion having teeth arranged continuously on the outer peripheral surface, and does not have a roller portion as in the above embodiment.

  Furthermore, in this embodiment, the extrusion head 18 is attached to the extrusion port O side of the casing 2. Further, the gear pump extruder 1 of the present embodiment includes a pressure detector 19 that detects the pressure downstream of the extrusion gears 3 and 4, and the second driving unit M <b> 2 based on the detection signal S <b> 1 of the pressure detector 19. And a control device CL for driving and controlling the pressure within a predetermined range.

  The pressure detector 19 is provided, for example, in the vicinity of the extrusion port O, and is provided in the upstream portion of the extrusion head 18 in this embodiment. The range of the appropriate pressure of the material at this position when obtaining an extruded product with higher quality can be known in advance by various experiments, and the value is preliminarily determined by the controller CL (this is a constant pressure value). Have a range of.)

  As the control device CL, for example, a programmable sequencer, a microcomputer, a personal computer, and other control devices can be used. A pressure signal S1 is input from the pressure detector 19 to the control device CL. The control device CL compares the pressure signal S1 with the appropriate pressure value stored in advance, and drives the second drive means M2 based on the result. In this embodiment, the control device CL When the signal S1 is smaller than the appropriate pressure value, the control signal S2 for increasing the rotation speed of the second drive unit M2 is output to the second drive unit M2. As a result, the rotation speed of the second drive means M2 increases, and more material can be supplied to the extrusion gears 3 and 4 by the feed gears 5 and 6.

  On the other hand, when the pressure signal S1 is larger than the appropriate pressure value, the control device CL outputs a control signal S2 for reducing the rotational speed of the second drive means M2, and feeds the feed gears 5 and 6 to the push gears 3 and 4. Reduce material supply. By performing such control in minute time steps, the pressure of the material near the extrusion port O can be controlled within an appropriate range, and the extrusion quality can be further improved.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the specific embodiment described above, and it is needless to say that the present invention can be implemented with various modifications.

1 is an overall plan view of a gear pump extruder showing an embodiment of the present invention. It is the front view. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. 3 except a gear part. It is CC sectional drawing of FIG. 3 except a gear part. It is sectional drawing which shows other embodiment of this invention. It is sectional drawing which shows an example of the conventional gear pump extruder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gear pump extruder 2 Casing 3, 4 Extrusion gear 5, 6 Feed gear 5G, 6G Gear part 5R, 6R Roller part 8 Cavity 9, 10, 11, 12 Rotating shaft 9 Extrusion gear drive means 19 Pressure detector CL Controller Y Material reservoir I Input port O Extrusion port M1 First drive means M2 Second drive means m Material

Claims (6)

A casing having a material supply port and an extrusion port; and a pair of extrusion gears arranged inside the casing and meshing with each other and driven by a first driving means, and the inner peripheral surface of the casing and the casing A gear pump extruder that feeds material from the supply port side to the extrusion port side between the tooth spaces of each extrusion gear,
A pair of feed gears for supplying the material charged from the supply port to the extrusion gear side inside the casing and between the extrusion gear and the supply port;
Each feed gear is provided so as not to mesh with any of the push gears, and at least one of the feed gears is rotationally driven by a second driving means different from the first driving means. And gear pump extruder.   The gear pump extruder according to claim 1, wherein the feed gear forms a material reservoir portion between the feed gear and the extrusion gear.   3. The gear pump extruder according to claim 2, wherein a volume of the material reservoir portion is 4 to 7 times a total sum of tooth gap volumes of the pair of extrusion gears and the pair of feed gears.   A pressure detector that detects the pressure downstream of the push gear, and a control device that drives the second driving means based on a detection signal of the pressure detector to control the pressure within a predetermined range. The gear pump extruder according to any one of claims 1 to 3, further comprising a gear pump extruder. The feed gear includes a first feed gear integrally including a gear portion and a roller portion that is provided adjacent to the rotation axis direction of the gear portion and has a diameter smaller than the diameter of the tooth tip circle of the gear portion; Consisting of a second feed gear,
The gear portion of the first feed gear faces the roller portion of the second feed gear, and the roller portion of the first feed gear faces the gear portion of the second feed gear, and the gear portion and the roller portion A gear pump extruder according to any one of claims 1 to 4, wherein a gap through which a material can pass is formed between the two.   The feed gear includes a first feed gear and a second feed gear that are separated from each other without being engaged with each other, and a gap through which material can pass is formed between the first feed gear and the second feed gear. The gear pump extruder according to any one of claims 1 to 4, wherein the gear pump extruder is provided.

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