JPH10153240A - Toothed belt and carriage driving mechanism of printer using toothed belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toothed belt capable of improving the recording quality by stably driving a carriage through a process of smoothly transmitting driving force of a driving motor to the carriage. SOLUTION: The twisting directions of respective core materials made into the same direction, the twisting direction to the core materials and the torsional direction of tooth traces of helical gears 18a, 20a are made into the same direction, driving force of a driving motor 24 is smoothly transmitted to a carriage 17 to stably drive the carriage 17, and therefore, the recording quality can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt and a carriage driving mechanism for a printer using the toothed belt, and more particularly, to a toothed belt and a toothed belt having a helical tooth formed on an inner peripheral surface. The present invention relates to a carriage driving mechanism of a printer using a belt.

[0002]

2. Description of the Related Art Conventionally, printers configured to reciprocate a carriage with a toothed belt have been used as output devices such as computers and word processors.

FIG. 7 and FIG. 8 show an example of such a carriage driving mechanism of a conventional printer. The carriage driving mechanism 1 of the conventional printer has a toothed belt 2 called a timing belt. doing. The toothed belt 2 includes a drive pulley 4 fixedly provided at a position apart from a moving range of the carriage 3 at a predetermined distance,
The toothed belt 2 is wound around a driven pulley 6 movably provided by a tension spring 5.
The carriage 3 is fixed to a part of.

[0004] A drive gear 7 is connected to a lower end surface of the drive pulley 4. That is, the drive pulley 4 and the drive gear 7 are formed integrally. The drive pulley 4 and the drive gear 7 are rotatably supported by being fitted to a small diameter portion of a support shaft 8 having an upper end formed with a small diameter step. Further, the drive pulley 4 and the drive gear 7 supported by the support shaft 8 are provided with an end face connecting the small diameter portion and the large diameter portion of the support shaft 8 and a stop disposed near the end surface of the small diameter portion of the support shaft 8. Positioning in the axial direction is performed by the wheel 9. The drive gear 7 includes an output shaft 1 of a drive motor 10.
A motor gear 11 such as a pinion attached to Oa is engaged.

According to the carriage driving mechanism 1 of the conventional printer configured as described above, the driving motor 10
, The toothed belt 2 can be rotated forward and reverse to reciprocate the carriage 3 in the left-right direction indicated by the double-headed arrow A in FIG.

[0006]

However, in the above-described carriage driving mechanism 1 of the conventional printer,
Each tooth 2 a, 4 a, formed on the toothed belt 2, the driving pulley 4, the driven pulley 6, the driving gear 7 and the motor gear 11.
Since the tooth shapes of 6a, 7a, and 11a are immediate (straight teeth), when the driving force of the driving motor 10 is transmitted to the carriage 3, when the toothed belt 2 and the driving pulley 4 mesh with each other or when the driving gear When the gear 7 and the motor gear 11 mesh with each other, that is, when the immediate teeth mesh, vibration of the tooth period occurs, and the driving force of the drive motor 10 cannot be transmitted to the carriage 3 smoothly. There is a problem that the carriage 3 also vibrates and deteriorates the recording quality of the printer.

[0007] The toothed belt 2 generally comprises
A plurality of core members 13 as shown in FIG. 9 are produced by twisting the thin wires 12 such as cotton thread and human silk thread, and these core members 13 are arranged in parallel at intervals and the outer periphery is made of resin or rubber. An endless annular belt is formed by mold coating of the molecular material, and a tooth profile is formed on the inner surface side of the belt. The tooth shape of the toothed belt 2 is usually short, but when it is necessary to prevent the vibration caused by the meshing of the teeth, the helical (beveled) toothed belt 2 is used. Used.

[0008] In the conventional toothed belt 2, the adjacent core members 13 are arranged such that the twisting directions of the adjacent core members 13 are opposite to each other. The influence of the orientation of the core 13 is canceled out.

However, when the carriage 3 is fixed to the conventional toothed belt 2 and used, the thrust acting on the toothed belt 2 in the thrust direction acting on the toothed belt 2 is received by the helical formed on the driving pulley 4 and the driven pulley 6. In some cases, the toothed belt 2 moves in the width direction. For this reason, the carriage 3 fixed to the toothed belt 2 swings in the width direction, which causes disturbance in recording,
Alternatively, there is a disadvantage that the driving of the carriage 3 becomes unstable because the tension is different in the width direction of the toothed belt 2.

The present invention has been made in view of these points, and a toothed belt capable of smoothly transmitting a driving force of a driving motor to a carriage and driving the carriage stably to improve recording quality. And a carriage driving mechanism for a printer using a toothed belt.

[0011]

In order to achieve the above-mentioned object, the feature of the toothed belt of the present invention described in claim 1 is that the direction of each core material is made the same and the core material has the same direction. The twist direction of the material is that the twist direction (twist direction) of the helical teeth is formed in the same direction.
By adopting such a configuration, it is possible to smoothly transmit the driving force of the driving motor to the carriage, drive the carriage stably, and improve the recording quality.

A feature of the toothed belt according to the second aspect is that the core is made of any one of a steel wire, a glass wire, and a Kevlar. By adopting such a configuration, even in the case of a toothed belt having a strong core material as a component, the driving force is smoothly transmitted to the carriage and the carriage is driven stably to improve the recording quality. be able to.

According to a third aspect of the present invention, a carriage driving mechanism of a printer using the toothed belt is characterized in that the teeth of the toothed belt, the driving pulley, the driven pulley, the driving gear, and the motor gear have a tooth profile. The twisted direction of the tooth of the drive gear and the twisted direction of the tooth of the drive pulley are formed in opposite directions, and the toothed belt according to claim 1 or 2 is used as a toothed belt. is there. By adopting such a configuration, it is possible to prevent the vibration of the tooth period, reduce the axial thrust generated on the drive pulley and the drive gear, and smoothly transmit the drive force from the drive motor to the carriage. And the vibration of the carriage can be suppressed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in the drawings.

FIGS. 1 and 2 show a main part of an embodiment of a carriage driving mechanism of a printer according to the present invention. FIG. 1 is a plan view, and FIG. It is a part cut enlarged front view.

As shown in FIGS. 1 and 2, the carriage driving mechanism 15 of the printer of the present embodiment has a toothed belt 16 called a timing belt. The toothed belt 16 is provided between a driving pulley 18 fixedly provided at a position outside the moving range of the carriage 17 at a predetermined distance and a driven pulley 20 movably provided by a tension spring 19. The carriage 17 is fixed to a part of the toothed belt 16.

A drive gear 21 is connected to a lower end surface of the drive pulley 18. That is, the drive pulley 18 and the drive gear 21 are formed integrally as a two-stage gear. The drive pulley 18 and the drive gear 21 are rotatably supported by being fitted to a small-diameter portion of a support shaft 22 having a small-diameter stepped upper end. Further, the support shaft 2
2, the driving pulley 18 and the driving gear 21
Positioning in the axial direction is performed by an end surface connecting the small diameter portion and the large diameter portion of the support shaft 22 and a retaining ring 23 disposed near the end surface of the small diameter portion of the support shaft 22. The drive gear 21 is meshed with a motor gear 25 such as a pinion attached to the tip of an output shaft 24 a of the drive motor 24.

The teeth 16a, 18a, 20a, 21a, 25a of the toothed belt 16, the driving pulley 18, the driven pulley 20, the driving gear 21, and the motor gear 25 are provided.
All of the teeth are slim.

Further, as shown in detail in FIG. 2, the direction in which the teeth 18a of the driving pulley 18 are twisted and the direction in which the teeth 21a of the driving gear 21 are twisted are opposite to each other. I have. That is, the teeth 18 of the driving pulley 18
When the torsion direction of the tooth trace of a is set to the left-hand twist (the tooth trace rises to the left as viewed from the axial direction), the teeth 2 of the drive gear 21
The spiral direction of the tooth trace 1a is formed as a right twist (the tooth trace rises to the right as viewed from the axial direction).

On the other hand, the structure of the toothed belt 16 will be described in more detail with reference to FIGS. FIG. 3A shows a toothed belt 16 with helical teeth running left-handed, and FIG. 3B shows a toothed belt 16 with helical teeth running right-handed.

In the toothed belt 16, a plurality of core members 27 formed by twisting fine wires 26 are arranged in parallel, and the outer periphery thereof is covered with a polymer material 28 such as resin or rubber by molding. As a result, an endless annular belt is formed, and a helical portion is formed on the inner surface side of the belt.

The core material 27 is formed by twisting a thin wire 26 having high mechanical strength, such as a steel wire, a glass wire, or an aramid synthetic fiber such as Kepler. The core material 27 is formed of a single yarn formed by a single thin wire 26 or a combined yarn obtained by twisting a plurality of thin wires 26, and the twist direction is “Z” from the left as shown in FIG. ”Or the twisting direction is“ right than S ”.

Further, as shown in FIG. 3, the respective core members 27 are arranged so that they are all in the same direction when they are arranged in parallel, and the direction is the same as that of the toothed belt 1.
The direction is the same as the torsion direction of the tooth trace No. 6. That is, in the case where the helical teeth of the toothed belt 16 are twisted leftward, as shown in FIG. 3A, the cores 27 in which all the directions of the cores 27 are leftward are arranged. Is established.
Conversely, when the helical teeth of the toothed belt 16 are right-handed, as shown in FIG. Will be arranged.
This is for canceling the thrust for moving the toothed belt 16 in the thrust direction by the force for canceling the twist of each core material 27 which is set in the same direction.

Next, the operation of the present embodiment having the above-described configuration will be described.

In the carriage driving mechanism 15 of the printer according to the present embodiment, when the driving motor 24 is rotated forward and backward, the motor gear 25 fixed to the output shaft 24a rotates forward and reverse.
The drive gear 21 meshing with the motor gear 25 also starts to rotate forward and reverse. Further, the driving pulley 18 formed integrally with the driving gear 21 rotates forward and backward, and the driven pulley 20 also rotates. Therefore, the toothed belt 16 wrapped around the driving pulley 18 and the driven pulley 20 rotates forward and backward, so that the carriage 17 can reciprocate in the left-right direction indicated by the double-headed arrow B in FIG. It has become.

According to the carriage driving mechanism 15 of the printer of this embodiment, the teeth 16a, 18a, 20a, 21a, 25a of the toothed belt 16, the driving pulley 18, the driven pulley 20, the driving gear 21, and the motor gear 25 are provided.
Since all of the tooth shapes are helical, it is possible to reliably prevent the vibration of the tooth period that occurs when the conventional immediate teeth mesh with each other. That is, each tooth 16a, 18a, 2
By setting the 0a, 21a, and 25a to be helical, the number of teeth that are simultaneously meshed at the time of meshing can be made plural, and it is possible to reliably prevent rattling when shifting from meshing of one tooth to meshing of the next tooth. .

Further, since the torsional direction of the teeth 18a of the drive pulley 18 and the torsional direction of the teeth 21a of the drive gear 21 are formed in opposite directions, the helical drive pulley 18 is formed. Since the direction of the axial thrust generated in the helical drive gear 21 can be made opposite to the direction of the axial thrust generated in the drive pulley 18, the shaft generated in the drive pulley 18 and the drive gear 21. Thrust in the direction can be reliably reduced. By reducing the axial thrust generated in the drive pulley 18 and the drive gear 21, the drive pulley 1 generated by the axial thrust is reduced.
8 and the end faces of the drive gear 21 can be prevented from being worn, and high reliability can be obtained over a long period of time.

It should be noted that the inclination angle of the tooth trace of the tooth 18a of the drive pulley 18 and the inclination angle of the tooth trace of the tooth 21a of the drive gear 21 are made equal in the axial direction generated in the drive pulley 18 and the drive gear 21. This is most preferable in reducing the thrust of the vehicle.

Furthermore, since the twisting direction of the helical helical teeth of the toothed belt 16 and the twisting direction of the core material 27 constituting the toothed belt 16 are formed in the same direction, Toothed belt 16 is used for driving pulley 1
8 and the driven pulley 20 can cancel out the thrust in the width direction caused by the meshing of the halves with the driven pulley 20.

That is, since the driving force is transmitted to the toothed belt 16 by the helical meshing of the driving pulley 18 and the driven pulley 20, the belt 16 receives a thrust in the width direction. For example, as shown in FIG. 5, when the carriage 17 moves in the direction of arrow C1 in FIG. 5, the toothed belt 16 receives a thrust in the direction of arrow D1, while the carriage 17 moves in the direction of arrow C2 in FIG. , The toothed belt 16 receives a thrust in the direction of arrow D2.

However, the toothed belt 16 is
Since all directions of the core material 27 are formed in the same direction as the helical twist direction, the torsional force of the core material 27 against the tension of the toothed belt 16 is opposite to the thrust in the width direction. Occurs. For example, if the helical belt shown in FIG.
6 moves in the arrow C1 direction, the drive pulley 18 rotates clockwise as viewed from above in FIG. 6 and moves rearward in FIG. 6 (the side that moves from the driven pulley 20 to the drive pulley 18).
The toothed belt 16 </ b> A located at the side of FIG.
The belt 16 </ b> B on the side that moves to the side becomes the belt on the loose side. For this reason, the tensioned toothed belt 16
A force acts in the direction of unwinding the core material 27 in A due to the tension, but the torsion force of the core material 27 opposing this force acts in the E1 direction, and the D1 direction due to the engagement of the helical member. To cancel the thrust.

Similarly, if the carriage 17 is
6, the driving pulley 18 rotates counterclockwise when viewed from above in FIG. 6 and the tooth located on the near side (the side moving from the driving pulley 18 to the driven pulley 20) in FIG. The attached belt 16B becomes the belt on the tension side, and FIG.
The toothed belt 16 </ b> A on the rear side (the side moving from the driven pulley 20 to the driving pulley 18) is the belt on the slack side. For this reason, a torsional force in the direction E2 acts on the core material 27 in the belt 16B on the tension side, and the thrust in the direction D2 due to the engagement of the helium can be canceled.

According to specific experimental results, the driving pulley 1
8 is 8 mm, the width of the toothed belt 16 is 4 mm, the helical angle is 10 degrees, and the twist direction is the left direction. Moves in the direction D1 in FIG.
8, the toothed belt 16 of the present embodiment moved about 1 mm in the direction D1 and stopped. This indicates that the thrust due to the helical meshing is suppressed by the twisting force of the fine wire 26.

Therefore, according to the toothed belt 16 and the carriage driving mechanism 15 of the printer using the toothed belt 16 in this embodiment, the toothed belt 16 moves in the axial direction of the driving pulley 18 and the driven pulley 20. Therefore, the driving force of the driving motor 24 can be smoothly transmitted to the carriage 17, and the carriage 17 can be prevented from being vibrated and driven stably to reliably improve the recording quality.

It should be noted that the present invention is not limited to the above-described embodiment, and can be changed as needed.

[0036]

As described above, according to the carriage driving mechanism of the printer of the present invention, the vibration of the tooth period can be prevented by forming the teeth in a helical shape. The force can be smoothly transmitted to the carriage, and the printing quality of the printer can be improved.

Further, by forming the inclination direction of the tooth trace of the drive gear and the inclination direction of the tooth trace of the drive pulley in opposite directions, the drive pulley which is generated when the tooth profile becomes helical, Since the thrust of the drive gear in the axial direction can be reduced, high reliability can be obtained for a long period of time.

Further, by forming the spiral direction of the helical teeth of the toothed belt and the twist direction of the core material constituting the toothed belt in the same direction, the toothed belt is driven and driven by a pulley. In other words, there is an excellent effect that the thrust in the width direction caused by the meshing with each other can be canceled by the twisting force of the core material.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of an embodiment of a carriage driving mechanism of a printer according to the present invention.

FIG. 2 is a partially cut-away enlarged front view of the vicinity of a drive gear of FIG. 1;

FIG. 3 is an explanatory view showing an embodiment of a toothed belt according to the present invention.

FIG. 4 is an explanatory view showing another embodiment of a core material constituting the toothed belt according to the present invention.

FIG. 5 shows the thrust in the belt width direction generated by the helical meshing of the toothed belt with the driving pulley and the driven pulley in the moving direction of the carriage in one embodiment of the carriage driving mechanism of the printer according to the present invention. Illustration

FIG. 6 is an explanatory diagram showing a thrust in a belt width direction generated in a toothed belt due to a torsion force of a core material with respect to a moving direction of a carriage in an embodiment of a carriage driving mechanism of a printer according to the present invention.

FIG. 7 is a plan view showing a main part of a carriage driving mechanism of a conventional printer.

FIG. 8 is a partially cut-away enlarged front view of the vicinity of the drive gear of FIG. 3;

FIG. 9 is an enlarged explanatory view showing a core material constituting a conventional toothed belt.

[Explanation of symbols]

 15 carriage drive mechanism of printer 16 toothed belt 16a (toothed belt) teeth 17 carriage 18 drive pulley 18a (drive pulley) teeth 20 driven pulley 20a (driven pulley) teeth 21 drive gear 21a (drive gear) teeth 24 Drive motor 25 Motor gear 25a (Motor gear) teeth 27 Core material

Claims (3)

[Claims] 1. A plurality of cores made of twisted fine wires are arranged in parallel, and an outer periphery of these cores is coated with a polymer material to form an endless ring, and a rim is formed on an inner surface thereof. A toothed belt, wherein the directions of the cores are made to be the same, and the direction of the cores and the direction of the torsion of the helical teeth are the same. Toothed belt. 2. The toothed belt according to claim 1, wherein the core is made of any one of a steel wire, a glass wire, and a Kepler. 3. A toothed belt is wound around a drive pulley and a driven pulley arranged at a predetermined distance, a carriage is fixed to a part of the toothed belt, connected to the drive pulley, and meshed with a motor gear. A carriage driving mechanism for driving the driving gear by a driving force of a driving motor to reciprocate the carriage, wherein the toothed belt, the driving pulley, the driven pulley, the driving gear, and the tooth shape of each tooth of the motor gear are formed. The toothed belt according to claim 1 or 2, wherein the torsional direction of the tooth trace of the drive gear and the torsional direction of the tooth trace of the drive pulley are formed in opposite directions, and the toothed belt is used as the toothed belt. And a carriage driving mechanism for the printer.