JP7640288B2 - Gear Manufacturing Equipment - Google Patents

Description

The present invention relates to a gear manufacturing device.

In recent years, gears made of resin have come to be used more and more due to the demand for lighter weight.
In order to increase the strength of such plastic gears, it has been proposed to blend reinforcing fibers into the base resin and to align the fiber direction of the reinforcing fibers uniformly along the meshing surfaces of each tooth (see, for example, Patent Document 1).

JP 2019-218994 A

However, the gears described above attempt to control the placement of reinforcing fibers by controlling the flow of the base resin material mixed with reinforcing fibers when filling a cavity formed in a resin molding die, and this was difficult to achieve and difficult to reproduce.

The present invention aims to provide a gear manufacturing device that can effectively control the placement of reinforcing fibers.

The present invention relates to
A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
The arrangement adjustment mechanism is a gear manufacturing device that arranges the reinforcing fibers so that they are more distributed at the tooth tip than at the tooth base .
In addition, another aspect of the present invention is
A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
The arrangement adjustment mechanism generates a magnetic field to the reinforcing fibers that are filled in the mold and have magnetism,
The arrangement adjustment mechanism is a gear manufacturing device that generates a rotating magnetic field.
Furthermore, still another aspect of the present invention is
A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
The arrangement adjustment mechanism is a gear manufacturing device in which a stronger electric field or stronger magnetic field is input to an area where the reinforcing fibers are arranged at a higher density than to an area where the reinforcing fibers are arranged at a lower density.

The present invention makes it possible to precisely control the placement of reinforcing fibers.

FIG. 1 is a side view of a gear manufacturing apparatus according to a first embodiment. FIG. 2(A) is a perspective view showing the positional relationship between a gear formed in a cavity of a mold and a placement adjustment mechanism provided in the mold, and FIG. 2(B) is an axial cross-sectional view taken along the central axis of the gear in the cavity. FIG. 11 is an axial cross-sectional view taken along the central axis of a gear when permanent magnets are arranged on both sides of the gear. FIG. 11 is an axial cross-sectional view taken along the central axis of a gear when electromagnets are arranged on both sides of the gear. FIG. 11 is a partial side view of a placement adjustment mechanism according to a second embodiment, as viewed from the axial direction. FIG. 6A is a partial side view of a position adjustment mechanism according to a third embodiment as viewed from the axial direction, and FIG. 6B is a diagram showing the waveform of an AC current applied to four electromagnets by a current-carrying portion. FIG. 7A is a perspective view of a position adjustment mechanism according to a fourth embodiment, and FIG. 7B is an axial cross-sectional view thereof. FIG. 13 is a cross-sectional view perpendicular to the axis of a mold provided with a placement adjustment mechanism according to a fifth embodiment. FIG. 13 is a cross-sectional view perpendicular to the axis of a mold provided with a placement adjustment mechanism according to a sixth embodiment.

[Embodiment 1]
A first embodiment of the present invention will be described in detail below with reference to the drawings. In the first embodiment, a gear manufacturing apparatus 1 for manufacturing a gear 100 in which reinforcing fibers (hereinafter, referred to as reinforcing fibers) are contained in a base material of a resin such as an engineering plastic is illustrated.

The resin base material of the gear 100 may be, for example, engineering plastics (general-purpose engineering plastics) such as polyamide (PA), polycarbonate (PC), polyacetal (POM), modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), etc., or super engineering plastics (special engineering plastics) such as polyether ether ketone (PEEK), polyamide imide (PAI), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), aromatic polyamide (PPA), liquid crystal polymer (LCP), polysulfone (PSU), polyether sulfone (PES), polyether imide (PEI), polyarylate (PAR), thermoplastic polyimide (TPI), etc. However, it is not limited to these and may be changed as appropriate.

Examples of reinforcing fibers include glass fibers, aramid fibers, polyethylene fibers, Zylon fibers, boron fibers, and carbon fibers. However, they are not limited to these and can be changed as appropriate. In addition, specific materials may be added to the reinforcing fibers.

The above-mentioned gear 100 is exemplified by a case in which the tooth tip portion 120 contains more reinforcing fibers than the tooth base portion 110, and further, a case in which the fiber direction of the reinforcing fibers is aligned with the meshing surface 121 of the tooth tip portion 120.

[General configuration of gear manufacturing device]
1 is a side view of a gear manufacturing apparatus 1. The gear manufacturing apparatus 1 has a basic structure of an injection molding apparatus. The gear manufacturing apparatus 1 includes a gear mold 20, a bed 11 that supports the entire apparatus, a mold clamping device 30 provided at one end (left side in the figure) of the bed 11, and an injection device 40 provided at the other end (right side in the figure) of the bed 11.

The mold clamping device 30 includes a pair of opposing wall portions 31, 32 fixed to the bed 11, four tie bars 33 connecting the pair of opposing wall portions 31, 32, a movable plate 34 slidably supported on each tie bar 33, and a fluid pressure cylinder 35 for reciprocating the movable plate 34 along each tie bar 33.

The mold 20 is composed of a pair of molds 21, 22, the mold 21 being held by a movable plate 34, and the mold 22 being held by an opposing wall portion 32. Each of the molds 21, 22 has a recess formed on its opposing surface that constitutes a cavity 23 for forming the gear 100. The mold 20 is also provided with an arrangement adjustment mechanism 24 that generates a magnetic field to adjust the arrangement of the reinforcing fibers in the molten resin in the mold 20.
The mold clamping device 30 maintains the mold 21 in a pressed state against the mold 22 held by the opposing wall portion 32 via a movable plate 34 using a fluid pressure cylinder 35, making it possible to fill the cavity 23 with the material for forming the gear 100 at a predetermined pressure.

The injection device 40 has a hopper 41 that supplies the molding material, a cylinder 42 that fills the mold 20 with the molding material, a screw (not shown) that stirs and sends out the molding material in the cylinder 42, a motor 43 that drives the screw, and a heater (not shown) that melts the molding material in the cylinder 42.

The hopper 41 supplies, for example, pellet-shaped base resin and reinforcing fibers into the cylinder 42. The base resin pellets and the reinforcing fibers may be separately charged into the hopper 41, or resin pellets containing the reinforcing fibers may be charged.
In the cylinder 42, the base resin is melted by the heater, and the resin and reinforcing fibers are stirred by the screw and sent to the tip side of the cylinder 42. At this time, the resin is also melted by shear friction heat caused by the screw.
The cylinder 42 has a nozzle at its tip, and is capable of filling the cavity 23 of the mold 20 with stirred molten resin and reinforcing fibers.

[Placement adjustment mechanism]
FIG. 2(A) is a perspective view showing the positional relationship between a gear 100 formed in a cavity 23 of a mold 20 and a placement adjustment mechanism 24 provided in the mold 20, and FIG. 2(B) is an axial cross-sectional view taken along the central axis C of the gear 100 in the cavity 23.

The position adjustment mechanism 24 is composed of a ring-shaped permanent magnet 241. This permanent magnet 241 is arranged so as to be concentric with the gear 100 in the cavity 23 in the mold 20. In addition, it is assumed that the mold 20 is made of a material that allows the magnetic flux of the permanent magnet 241 to easily pass through.
The inner diameter of the permanent magnet 241 approximately matches the outer diameter of the tooth bottom surface 122 of the gear 100 , and the outer diameter of the permanent magnet 241 approximately matches the outer diameter of the tooth tip surface 123 of the gear 100 .
The inner diameter of the permanent magnet 241 may be equal to or greater than the outer diameter of the tooth bottom surface 122 and less than the outer diameter of the tooth tip surface 123 , and the outer diameter of the permanent magnet 241 may be greater than the outer diameter of the tooth tip surface 123 .

Further, the permanent magnet 241 is arranged so that the surface facing the gear 100 is the N pole and the surface opposite thereto is the S pole in the direction along the central axis C (hereinafter referred to as the axial direction). Note that the orientation of the N pole and the S pole may be reversed.
With the above arrangement, the magnetic field lines representing the magnetic field generated by the permanent magnets 241 pass through the tooth tip 120 of the gear 100 in the axial direction with the highest magnetic flux density.
A yoke having high magnetic permeability for guiding the magnetic lines of the permanent magnet 241 in an appropriate direction may be provided in addition to the permanent magnet 241 .

In contrast, the reinforcing fibers contained in the molten resin of the gear 100 are made of or contain a ferromagnetic material. Therefore, the molten resin containing the reinforcing fibers is attracted to the magnetic field during the process of filling the cavity 23. This allows the reinforcing fibers to be distributed more in the tooth tip portion 120 of the gear 100 than in the tooth base portion 110.

Also, as shown in FIG. 3, the permanent magnets 241 may be arranged on either side of the cavity 23 in the axial direction. In this case, it is preferable that the polarity of each permanent magnet 241 is aligned in the same direction. This allows the magnetic field lines formed by the permanent magnets 241 on both sides to pass through the tooth tip 120 of the gear 100 in the axial direction with a higher magnetic flux density, so that the reinforcing fibers can be more effectively collected at the tooth tip 120 of the gear 100.

As shown in FIG. 4, the position adjustment mechanism 24 may have an electromagnet 241A made of a coil instead of the permanent magnet 241, and an electric current supply unit (not shown) that supplies electric current to the electromagnet 241A.
The electromagnet 241A may be provided on either one or both sides of the cavity 23 in the axial direction.
The electromagnet 241A is in the shape of a ring concentric with the gear 100 formed in the cavity 23, and the inner diameter of the electromagnet 241A is approximately the same as the outer diameter of the tooth tip surface 123 of the gear 100, but may be set to be somewhat larger than this. In the case of the ring-shaped electromagnet 241A, the magnetic field lines pass through the inner diameter side and the outer diameter side, so it is preferable that the outer diameter of the electromagnet 241A is larger than that of the permanent magnet 241.
In addition, when the electromagnet 241A is used, the strength of the magnetic field can be adjusted by adjusting the value of the current applied to the electromagnet 241A by the current-carrying unit. This makes it possible to adjust the ratio of the content of the reinforcing fibers in the tooth base 110 and the tooth tip 120.

Furthermore, the reinforcing fibers contained in the molten resin of the gear 100 may be made of or contain a hard magnetic material, so that a magnetized state having a polarity in a direction along the fibers can be maintained. In this case, it becomes possible to align the reinforcing fibers in the cavity 23 with the magnetic field lines formed by the permanent magnet 241 or the electromagnet 241A.
In the case of the arrangement of the permanent magnets 241 or electromagnets 241A shown in FIGS. 2 to 4 described above, the reinforcing fibers in the gear 100 can be aligned in the axial direction.

In addition, when the reinforcing fibers are to have a magnetic polarity, the magnet 241 or electromagnet 241A may be arranged so that the magnetic field lines are oriented in the radial direction of the gear 100 formed in the cavity 23.
In this case, for example, radially magnetized ring-shaped permanent magnets may be disposed on the radially outer and inner sides of gear 100 formed in cavity 23. Alternatively, electromagnets each having a plurality of coils centered in the radial direction arranged along a circumference concentric with gear 100 may be disposed on the radially outer and inner sides of gear 100.

[Gear manufacturing using gear manufacturing equipment]
The operation of manufacturing the gear 100 by the gear manufacturing apparatus 1 configured as above will now be described.
First, the die 21 of the metal mold 20 is attached to the movable plate 34, and the die 22 is attached to the opposing wall portion 32. Then, in the mold clamping device 30, the fluid pressure cylinder 35 is driven to move the movable plate 34 toward the opposing wall portion 32, and the die 21 is pressed against the die 22. As a result, the cavity 23 between the die 21 and the die 22 is sealed from the outside.

Meanwhile, pellets of the base resin that will be the molding material for the gear 100 and reinforcing fibers are placed in the hopper 41 of the injection device 40. The molding material for the gear 100 is then supplied from the hopper 41 into the cylinder 42, where it is heated by the heater and stirred by the screw. The pellets become molten resin, and are sent by the screw to the tip side of the cylinder 42 with the reinforcing fibers still included, and are filled into the cavity 23 of the mold 20 from the tip of the cylinder 42.

In the mold 20, the permanent magnet 241 of the positioning adjustment mechanism 24 is arranged so that the magnetic field lines pass through the tooth tip portion 120 of the gear 100 in the cavity 23, and the magnetic reinforcing fibers move to gather at the tooth tip portion 120.
Then, after the cooling time of the gear 100 has elapsed, the mold 21 is separated from the mold 22 by the mold clamping device 30, and the gear 100 is removed from the cavity 23, completing the manufacturing process.
This produces a gear 100 in which the reinforcing fibers are concentrated more in the tooth tip 120 than in the tooth base 110 .
Furthermore, in the case where the reinforcing fibers have magnetic polarity, a gear 100 is manufactured in which the fiber direction is uniformly aligned parallel to the magnetic lines of force.

[Technical effect of the first embodiment]
As described above, the gear manufacturing apparatus 1 adjusts the arrangement of the reinforcing fibers by generating a magnetic field using the arrangement adjustment mechanism 24 for the molten resin containing magnetic (ferromagnetic or including ferromagnetic) reinforcing fibers in the mold 20.
Therefore, the reinforcing fibers in the molten resin can be guided to a predetermined arrangement within the mold 20, making it possible to properly manufacture the gear 100 with the desired reinforced resin arrangement.

In the above-described arrangement adjustment mechanism 24, an example has been shown in which the permanent magnet 241 is arranged so that the magnetic field lines pass through the gear 100 in a direction along the central axis C of the gear 100, but the present invention is not limited to this.
For example, a ring-shaped permanent magnet may be disposed on the radially outer side of the gear 100 to induce more reinforcing fibers on the tooth tip 120 side.
Alternatively, ring-shaped permanent magnets may be arranged on the radially outer and inner sides of the gear 100, so that magnetic field lines in the magnetic field pass through the gear 100 in a direction along the radial direction of the gear 100. This makes it possible to align the fiber direction of the reinforcing fibers along the radial direction of the gear 100 when the reinforcing fibers have polarity.

[Embodiment 2]
A second embodiment of the present invention will be described with reference to Fig. 5. In the first embodiment, the arrangement adjustment mechanism 24 that forms a magnetic field with magnetic lines of force oriented in a fixed direction (axial direction) with respect to the gear 100 in the cavity 23 is exemplified, but the present invention is not limited to this.
In the second embodiment, a gear manufacturing apparatus is exemplified that can randomize the fiber direction of the reinforcing fibers of the gear 100 by using a placement adjustment mechanism 24B that generates a rotating magnetic field in which the direction and position of the magnetic field lines change.
Regarding the gear manufacturing apparatus of the second embodiment, only the differences from the gear manufacturing apparatus 1 will be described, and the same components will be given the same reference numerals and redundant description will be omitted.

FIG. 5 is a partial side view of a placement adjustment mechanism 24B according to the second embodiment as viewed from the axial direction.
The placement adjustment mechanism 24B has a plurality of permanent magnets 241B arranged closely facing one axial side of each tooth tip portion 120 of the gear 100 in the cavity 23, and a rotation drive unit (not shown) that rotates each permanent magnet 241B.

Each permanent magnet 241B is magnetized so that a circular surface facing the axial end face of the tooth tip portion 120 is divided into an S pole and an N pole in the diametrical direction.
The rotary drive unit rotates the permanent magnet 241B around an axis that is parallel to the central axis C and passes through the center of the circle.

The permanent magnet 241B is not limited to being circular, and may be structured so that the S pole and the N pole alternately face a certain portion of the axial end face of the tooth tip portion 120. For example, the shape of the facing surface of the permanent magnet 241B may be different, or one end and the other end of a rod-shaped permanent magnet may be capable of facing the gear 100 alternately.
Furthermore, a rotation drive unit may be provided for each permanent magnet 241B. In this case, the rotation speed of each permanent magnet 241B may be uniform or non-uniform.
Furthermore, the rotation drive unit may rotate all of the permanent magnets 241B simultaneously using rollers that simultaneously circumscribe the outer periphery of all of the permanent magnets 241B, or may utilize a gear transmission mechanism.

In a gear manufacturing apparatus equipped with the above-mentioned arrangement adjustment mechanism 24B, each permanent magnet 241B is rotationally driven relative to the molten resin containing reinforcing fibers filled in the cavity 23 of the mold 20. As a result, the reinforcing fibers in each tooth tip 120 of the gear 100 closely facing each permanent magnet 241B are randomly stirred in the rotating magnetic field in which the direction and position of the magnetic field fluctuate drastically.
This makes it possible to manufacture a gear 100 having a tooth tip 120 in which the orientation of the reinforcing fibers is random.
In the placement adjustment mechanism 24B, an example has been given of the permanent magnet 241B and the rotational drive unit being provided on only one axial side of the tooth tip portion 120 of the gear 100, but the permanent magnet 241B and the rotational drive unit may also be provided on both axial sides.

The arrangement adjustment mechanism 24B may be used in combination with other arrangement adjustment mechanisms. For example, an arrangement adjustment mechanism that forms a magnetic field that attracts reinforcing fibers to the tooth tip portion 120 or a part thereof (e.g., the meshing surface 121) and an arrangement adjustment mechanism 24B that forms a rotating magnetic field on the tooth base portion 110 side may be provided, so that, for example, the reinforcing fibers are concentrated on the tooth tip portion 120 side or aligned with the meshing surface 121, while on the tooth base portion 110 side, the gear 100 may be manufactured in a state in which the individual reinforcing fibers are oriented in random directions.

[Embodiment 3]
A third embodiment of the present invention will be described with reference to Fig. 6. In the third embodiment, a gear manufacturing apparatus is illustrated in which the fiber direction of the reinforcing fibers of the gear 100 is randomized by a placement adjustment mechanism 24C that generates a rotating magnetic field similar to the placement adjustment mechanism 24B described above.
Regarding the gear manufacturing apparatus of the third embodiment, only the points that are different from the gear manufacturing apparatus 1 will be described, and the same components will be given the same reference numerals and duplicated descriptions will be omitted.

FIG. 6A is a partial side view of a placement adjustment mechanism 24C according to the third embodiment as viewed from the axial direction.
The arrangement adjustment mechanism 24C has multiple sets of electromagnets 241C arranged individually in close proximity to one axial side of each tooth tip portion 120 of the gear 100 in the cavity 23, and an electrical current supply unit (not shown) that supplies AC current to each electromagnet 241C.

Four electromagnets 241C are arranged close to one tooth tip 120 of the gear 100 in the cavity 23, facing one axial end face of the tooth tip 120. The four electromagnets 241C have their coil central axes oriented parallel to the central axis C of the gear 100, and are arranged at each vertex of a square when viewed from the axial direction of the gear 100. The winding direction of each coil is the same.

Figure 6(B) is a diagram showing the waveform of the alternating current that the current-carrying unit applies to the four electromagnets 241C. In Figure 6(B), the horizontal axis is time, and the vertical axis is current value. In Figure 6(A), the four electromagnets 241C are numbered "1," "2," "3," and "4" in counterclockwise order, and these correspond to the numbers assigned to the four waveforms in Figure 6(B).

As shown in the figure, the current supply unit supplies AC current to the four electromagnets 241C with a quarter-cycle delay in accordance with the above-mentioned order of "1,""2,""3," and "4." This creates a rotating magnetic field in which the position of the strong magnetic field lines rotates.
The timing pattern of the AC current passing through the four electromagnets 241C may be changed so that the four electromagnets 241C are not the same. For example, the phase may be shifted regardless of the arrangement order, or two of the electromagnets may have different phases. In this case, although it does not become a rotating magnetic field, it is possible to stir the reinforcing fibers and randomize them.

In a gear manufacturing apparatus equipped with the above-mentioned position adjustment mechanism 24C, the molten resin filled in the cavity 23 of the mold 20 has reinforcing fibers stirred by a rotating magnetic field formed by four electromagnets 241C that are energized at different phases for each tooth tip portion 120.
This makes it possible to manufacture a gear 100 having tooth tips 120 in which the reinforcing fibers are randomly arranged within each tooth tip 120 of the gear 100 .

In the arrangement adjustment mechanism 24C, four electromagnets 241C are provided only on one axial side of the tooth tip portion 120 of the gear 100, but four electromagnets 241C may be provided on both axial sides. Also, the number of electromagnets 241C may be more than one and may be increased or decreased.
Further, like the placement adjustment mechanism 24B, the placement adjustment mechanism 24C may be used in combination with another placement adjustment mechanism.

[Embodiment 4]
A fourth embodiment of the present invention will be described with reference to Fig. 7. In the fourth embodiment, a gear manufacturing apparatus having a placement adjustment mechanism 24D that inputs a stronger magnetic field to an area where reinforcing fibers are arranged at a higher density than to an area where reinforcing fibers are arranged at a lower density is illustrated. In this placement adjustment mechanism 24D, a case is illustrated in which the tooth tip 120 of the gear 100 is set as the area where reinforcing fibers are arranged at a higher density, and the tooth base 110 is set as the area where reinforcing fibers are arranged at a lower density.
For the gear manufacturing apparatus of the fourth embodiment, only the points that are different from the gear manufacturing apparatus 1 will be described, and the same components will be given the same reference numerals and duplicated descriptions will be omitted.

FIG. 7A is a perspective view of a placement adjustment mechanism 24D according to the fourth embodiment, and FIG. 7B is an axial cross-sectional view thereof.
As shown in the figure, the placement adjustment mechanism 24D has the aforementioned permanent magnet 241 that axially faces the tooth tip portion 120 of the gear 100 in the cavity 23, and a permanent magnet 242D that axially faces the tooth base portion 110 of the gear 100 inside the permanent magnet 241.

The permanent magnet 242D is selected from those having a magnetic field with a smaller magnetic flux density (smaller magnetic force) than the permanent magnet 241.
Like the permanent magnet 241, the permanent magnet 242D is arranged in a direction along the central axis C (hereinafter referred to as the axial direction) such that the surface facing the gear 100 is the N pole and the opposite surface is the S pole. Note that it is preferable to align the N and S poles with those of the permanent magnet 241, but the orientations of both the permanent magnets 241 and 242D may be opposite. With this arrangement, the magnetic field lines indicating the magnetic field formed by the permanent magnet 242D pass through the tooth base 110 of the gear 100 in the axial direction.

By the arrangement adjustment mechanism 24D having the above-mentioned configuration, reinforcing fibers can be arranged at a high density in the tooth tip portion 120 within the mold 20, and at a lower density in the tooth base portion 110 compared to the tooth tip portion 120.
This allows the gear manufacturing apparatus to distribute reinforcing fibers to each part of gear 100 with the required strength, making it possible to manufacture gears appropriate for their intended use.

In the case of the above-mentioned arrangement adjustment mechanism 24D, the permanent magnets 241 and 242D may also be provided on both sides of the gear 100 in the axial direction.
Also, in the case of the position adjustment mechanism 24D, the two permanent magnets 241 and 242D may be replaced with electromagnets. In this case, it is preferable to adjust the magnetic flux density of the electromagnet replacing the permanent magnet 242D by the number of turns of the coil or the magnitude of the current passing through it.

[Embodiment 5]
A fifth embodiment of the present invention will be described with reference to Fig. 8. In the fifth embodiment, a gear manufacturing apparatus having an arrangement adjustment mechanism 24E for arranging reinforcing fibers more locally so that the fiber direction is along a predetermined surface of the gear 100 is illustrated. The arrangement adjustment mechanism 24E arranges reinforcing fibers on or near the meshing surface 121, the root surface 122, and the tip surface 123 of the tooth tip portion 120 of the gear 100 in a state along each of the surfaces 121 to 123.
For the gear manufacturing apparatus of the fifth embodiment, only the differences from the gear manufacturing apparatus 1 will be described, and the same components will be given the same reference numerals and redundant description will be omitted.

FIG. 8 is a cross-sectional view perpendicular to the axis of a mold 20 provided with a placement adjustment mechanism 24E according to the fifth embodiment.
As shown in the figure, the position adjustment mechanism 24E has a permanent magnet 241E that faces each of the meshing surface 121, the bottom surface 122 and the tip surface 123 of the tooth tip portion 120 over the entire circumferential direction of the radially outer side of the gear 100 in the cavity 23.
Although the surface of the permanent magnet 241E constitutes the inner surface of the cavity 23 and comes into direct contact with the molding material of the gear 100, the present invention is not limited to this.
The permanent magnet 241 may be embedded shallowly in the mold 20 so as not to come into contact with the molding material of the gear 100 .

The permanent magnet 241E of the position adjustment mechanism 24E attracts the reinforcing fibers within the cavity 23 to or near the meshing surface 121, the bottom surface 122, and the tip surface 123, so that the fiber direction is aligned with each surface.
In this way, by using a gear manufacturing apparatus having the arrangement adjustment mechanism 24E, it is possible to gather the reinforcing fibers in the tooth tip portion 120 of the gear 100 and arrange the fiber direction of each reinforcing fiber in accordance with the meshing surface 121, the bottom surface 122 and the tip surface 123.

When the fiber direction of each reinforcing fiber is arranged so that it is aligned along only some of the surfaces, rather than along all of the meshing surface 121, the tooth bottom surface 122, and the tooth tip surface 123, it is preferable to provide multiple permanent magnets in the mold 20 that face only those surfaces.

[Embodiment 6]
A sixth embodiment of the present invention will be described with reference to Fig. 9. In each of the first to fifth embodiments described above, the arrangement adjustment mechanisms 24 to 24E each form a magnetic field to control the reinforcing fibers, but in the sixth embodiment, a gear manufacturing apparatus is illustrated that includes an arrangement adjustment mechanism 24F that forms an electric field to control the reinforcing fibers.

FIG. 9 is a cross-sectional view perpendicular to the axis of a mold 20 provided with a placement adjustment mechanism 24F according to the sixth embodiment.
As shown in the figure, the positioning adjustment mechanism 24F includes a first electrode 241F that faces the meshing surface 121, bottom surface 122 and tip surface 123 of the tooth tip portion 120 over the entire circumferential direction of the radially outer side of the gear 100 in the cavity 23, a second electrode 242F that faces the inner circumferential surface of the gear 100 over the entire circumferential direction of the radially outer side of the gear 100, and a voltage application device 243F that applies a voltage between the first electrode 241F and the second electrode 242F to generate a potential difference.

The first electrode 241F and the second electrode 242F of the position adjustment mechanism 24F are provided with an insulating structure with respect to the surroundings.
The first electrode 241F and the second electrode 242F may be embedded shallowly within the mold 20 so as not to come into contact with the molding material of the gear 100.

In the sixth embodiment, the reinforcing fibers contained in the molten resin of the gear 100 are formed from an easily charged material (e.g., carbon fiber) or are formed containing an electrostatically charged material. In addition, such an electrostatically charged material has either a positive or negative charge polarity, but one that has a polarity opposite to that of the first electrode 241F arranged in the direction in which the reinforcing fibers are to be attracted is used. For example, when a positive voltage is applied to the first electrode 241F, the reinforcing fibers are formed from an electrostatically charged material that has a negative charge polarity or are configured to contain an electrostatically charged material.

The reinforcing fibers may be prepared in advance in an electrically charged state and then fed into the hopper 41 of the injection device 40, or the injection device 40 may be provided with a charging mechanism for charging the reinforcing fibers.
For example, the charging mechanism may be configured to charge the reinforcing fibers by corona discharge when the fibers are fed into the hopper 41, or may be configured to charge the reinforcing fibers by frictional charging.
Furthermore, when the reinforcing fibers are made of an electrostatically charged material that easily becomes charged by friction or contain the same electrostatically charged material, the fibers may be configured to be charged by friction during stirring by the screw inside the cylinder 42. In this case, the screw functions as a charging mechanism.

In the case of a gear manufacturing apparatus equipped with the above-mentioned placement adjustment mechanism 24F, when a voltage is applied to each electrode 241F, 242F so that the first electrode 241F has positive polarity, an electric field is formed consisting of electric field lines extending from the first electrode 241F to the second electrode 242F.
Then, when the molten resin containing the charged reinforcing fibers is filled into the cavity 23, the negatively charged reinforcing fibers are attracted to or near each of the meshing surface 121, the bottom surface 122, and the tip surface 123, and the fiber direction is aligned with each surface.
In this way, by using a gear manufacturing apparatus having the arrangement adjustment mechanism 24F, in the gear 100, it is possible to gather the reinforcing fibers at the tooth tip portion 120 and arrange the fiber direction of each reinforcing fiber in accordance with the meshing surface 121, the bottom surface 122 and the tip surface 123.

In addition, by appropriately adjusting the voltage applied by the voltage application device 243F between the first electrode 241F and the second electrode 242F to be lower, it is possible to arrange the reinforcing fibers so that they are more distributed in the tooth tip portion 120 than in the tooth base portion 110, without being aligned with the meshing surface 121, the tooth bottom surface 122, and the tooth tip surface 123.

In addition, if the reinforcing fibers are configured to be charged, for example, so that one side of the fiber direction is positive and the other side is negative, it is also possible to control the fiber direction of the reinforcing fibers so that they are aligned along the electric field lines.

When the fiber direction of each reinforcing fiber is arranged so that it is aligned along only some of the surfaces, rather than along all of the meshing surface 121, the tooth bottom surface 122, and the tooth tip surface 123, it is preferable to provide multiple first electrodes 241F on the mold 20 that face only those surfaces.

[others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.
For example, in each of the first to sixth embodiments, the gear manufacturing apparatus has been described as manufacturing an external gear as gear 100, but this is not limited to external gears, and it is also possible to manufacture internal gears and various other types of gears.
In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention.

1 Gear manufacturing device 11 Bed 20 Mold 21, 22 Mold 23 Cavity 24 to 24F Arrangement adjustment mechanism 30 Mold clamping device 31, 32 Opposing wall portion 33 Tie bar 34 Movable plate 35 Fluid pressure cylinder 40 Injection device 41 Hopper 42 Cylinder 43 Motor 100 Gear 110 Tooth base portion 120 Tooth tip portion 121 Meshing surface 122 Tooth bottom surface 123 Tooth tip surface 241, 241B, 242D, 241E Permanent magnet 241A, 241C Electromagnet 241F First electrode 242F Second electrode 243F Voltage application device C Central axis

Claims (9)

A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
The arrangement adjustment mechanism is a gear manufacturing device that arranges the reinforcing fibers so that they are more distributed at the tooth tip portion than at the tooth base portion . The gear manufacturing apparatus according to claim 1 , wherein the arrangement adjustment mechanism generates an electric field for the reinforcing fibers filled in the mold and charged. 3. A gear manufacturing apparatus according to claim 1, further comprising a charging mechanism for charging the reinforcing fibers. The gear manufacturing apparatus according to claim 1 , wherein the arrangement adjustment mechanism generates a magnetic field for the reinforcing fibers filled in the mold and having magnetic properties. A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
The arrangement adjustment mechanism generates a magnetic field to the reinforcing fibers that are filled in the mold and have magnetism,
The arrangement adjustment mechanism is a gear manufacturing device that generates a rotating magnetic field . 6. The gear manufacturing apparatus according to claim 5, wherein the arrangement adjustment mechanism generates the rotating magnetic field when the fiber direction is random. The gear manufacturing apparatus according to claim 1 , wherein the arrangement adjustment mechanism is capable of adjusting the strength of an electric field or a magnetic field. A gear manufacturing apparatus for manufacturing gears using a resin containing electrostatically or magnetically reinforcing fibers,
A mold into which the molten resin containing the reinforcing fibers is filled;
A placement adjustment mechanism that generates an electric field or a magnetic field and adjusts the placement of reinforcing fibers in the molten resin in the mold;
Equipped with
A gear manufacturing apparatus wherein the arrangement adjustment mechanism inputs a stronger electric field or magnetic field to an area where the reinforcing fibers are arranged at a higher density than to an area where the reinforcing fibers are arranged at a lower density . The gear manufacturing apparatus according to claim 8 , wherein the arrangement adjustment mechanism applies a stronger electric field or a stronger magnetic field to a tooth tip portion of the gear than to a tooth base portion.

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