JPH10153243A - Toothed belt driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve printing accuracy and conveying accuracy by bringing a belt tooth tip and a pulley tooth bottom part in contact with each other, expanding the dedendum part from the belt tooth pressure surface by compressing the belt tooth, and extremely decreasing the momentary speed variation by eliminating a clearance between the belt tooth and a pulley. SOLUTION: In a toothed belt driving device is so formed that the depth of a pulley groove part 18 of a toothed pulley 10 may be lower than the height of a belt tooth part 2 and that the ratio of the belt tooth part height to the pulley groove part depth may be 1.00 or more and also 1.20 or less in the linear measurement. When a belt 1 and the pulley 10 are completely engaged with each other, the belt tooth 2 is compressed in the height direction, the belt tooth 2 are expanded, a clearance between the belt tooth and the pulley 10 is completely eliminated, and therefore, the belt tooth 2 is not moved on the pulley 10, and the center line of the pulley groove 18 and the center line of the belt tooth 2 are made to approximately coincide with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toothed belt driving device, and more particularly to a driving device for a conveying belt used for a carriage belt for a printer, a belt for conveying bills, a belt for conveying cards, and the like.

[0002]

2. Description of the Related Art Conventionally, in a conveyor belt driving apparatus as described above, a toothed belt is generally used for reliable transmission, and the belt is wound around at least a pair of toothed pulleys to perform reciprocating motion or one-way motion. However, today's toothed belt driving device is a combination or a pair of a toothed belt having inverted trapezoidal teeth and a pulley having a pulley groove having the same shape as the belt teeth. The mainstream is a combination of a toothed belt having round teeth formed by a part of an arc surface and a pulley having a pulley groove having a shape similar to the round teeth.

[0003] In these transmissions, the toothed belt and the pulley, particularly the pulley for Starmax, have a greater depth of the tooth groove of the pulley than the height of the belt teeth in order to avoid contact with the tooth tip of the belt. It is made. Conventionally, an aramid fiber rope or a glass fiber rope is usually used as a core wire of a belt used, and the aramid fiber rope is, for example, disclosed in Japanese Patent Application Laid-Open No. 54-74341.
As disclosed in Japanese Patent Publication No. 135954, a yarn having a twist coefficient of 1.4 to 2.6 and a thickness of 300 to 500 deniers is used, and as an aramid fiber rope, a plurality of raw yarns are aligned and twisted, and Those that have undergone an adhesive treatment have been developed and used. On the other hand, glass fiber ropes are also used after being subjected to an adhesive treatment.

[0004]

However, if the depth of the groove of the pulley is made larger than the height of the belt teeth in order to avoid contact with the teeth of the belt as described above, the teeth of the belt will not contact the pulley. However, when the belt is wound around the pulley, as shown in FIG. 11, the belt is supported only by the tooth tips of the pulley 10, so that the core of this portion is straight, and the belt 1 is slightly broken. The shape of the pitch line 4 is changed to a polygonal pitch line 4 to cause a large speed fluctuation.

As described above, if the tooth tip of the belt 1 does not contact the bottom of the groove of the pulley 10, if a torque is applied, as shown in FIGS. Due to the deformation of the belt 1, the belt 1 is pressed against the side surface of the pulley 10 on one side, and the center of the belt teeth and the pulley groove is shifted. Tooth movement causes run-out, and the tooth tip of the belt and the pulley tip easily interfere with each other.At the belt entrance of the driving pulley, there is a problem that interference occurs particularly when the single pitch of the belt is slightly longer than the pulley. is there.

The present invention has been made to solve such a problem. In particular, the present invention considers the relationship between the height of the toothed belt and the depth of the pulley groove of the above-mentioned toothed belt driving device, thereby providing a carriage belt for a printer and a bill transporter. Toothed belt drive device used for belts, card conveyor belts, etc., causes the tip of the belt teeth and the bottom of the pulley teeth to interfere (contact) with each other and compress the belt teeth to thereby reduce the tooth root portion from the belt tooth pressure surface. The objective of the present invention is to reduce the speed fluctuation rate by eliminating gaps (backlash) with the pulleys as much as possible, thereby improving printing accuracy or transport accuracy.

[0007]

That is, a feature of the present invention that meets the above-mentioned object is that a toothed belt driving device which reciprocates or unidirectionally moves by winding a toothed belt between at least a pair of toothed pulleys. Attention is paid to the height of the belt teeth and the depth of the pulley groove, and the latter is smaller than the former when measured linearly, and the belt tooth height / pulley groove depth is 1.0
When the belt and the pulley are completely engaged, the belt teeth are compressed in the height direction, so that the belt teeth expand and the clearance between the belt and the pulley is increased. , The belt tooth does not move on the pulley, and the center line of the pulley groove and the center line of the belt tooth substantially coincide with each other.

A second aspect of the present invention relates to a mode of mutual contact at the beginning of engagement of the belt teeth with the pulley groove based on the above configuration. The center of the completely engaged belt tooth and the pulley groove substantially coincides with each other. The meshing of the belt teeth and the center of the pulley groove engages so that the centers of the belt teeth and the pulley groove substantially coincide with each other. At the beginning of the engagement of the belt teeth with the pulley groove, the belt teeth make contact only at the side of the pulley groove and at a position below a depth of 1/2. It is characterized by starting.

A third aspect of the present invention further embodies the configuration of the toothed belt and the pulley of the toothed belt driving device according to the present invention, wherein the toothed belt is provided on a pitch line of a belt body formed of an elastic material. The tooth is buried at a constant pitch on the back side of the belt body, and the side wall of the tooth forming a part of the back side of the belt is formed with a convex arc surface, The groove wall of the groove group of the peripheral surface of the pulley is formed by a concave arcuate surface, and in a static meshing state of the toothed belt and the pulley, the tooth tip of the belt tooth contacts the tooth bottom of the pulley groove, and The backlash between the belt teeth and the pulley grooves is configured to gradually increase from the root of the belt to the tip of the belt, and the depth of the pulley grooves is made smaller than the height of the belt teeth.

Claims 4, 5 and 6 relate to the core wire of the toothed belt used in the toothed belt driving device. Claims 4 and 5 relate to a monofilament of 0.5 to 2.0 denier as a material of the core wire. Characterized by a configuration using one of an aramid fiber obtained by bundling and twisting at least one filament group obtained by converging aramid fibers consisting of E glass or a high-strength glass twisted with a filament having a diameter of 5 to 9 μm. I have. The pitch between the cords including the cords is 0.2 to 0.5 m as described in claim 6.
It is preferable to set the range of m.

A seventh aspect of the present invention is an overall configuration of the belt driving device of the present invention, wherein the toothed belt is wound around at least a pair of toothed pulleys to perform a reciprocating motion or a one-way motion. When the belt tooth height / pulley groove depth is greater than 1.00 and less than or equal to 1.20 when the belt pitch is 2.5 mm or less and measured in a straight line, the belt is completely engaged with the pulley. When the teeth are compressed in the height direction, the belt teeth expand, the gap with the pulley is completely eliminated, the belt teeth do not move on the pulley, and the center line of the pulley groove and the center line of the belt teeth substantially coincide. By doing so, the center of the pulley groove and the next tooth to be meshed with each other are meshed so that the belt tooth is engaged with the pulley groove at the start of engagement with the side of the pulley groove.
It is characterized by a configuration that initiates contact only at positions below a depth of / 2.

[0012]

According to the present invention, in the toothed belt driving device, interference between the tooth of the toothed belt and the depth of the groove of the pulley is made to be a shallow tooth groove pulley as required, so that interference with the belt teeth can be prevented. By reducing the fluctuation, the fluctuation of the belt speed is suppressed, so that the printing accuracy and the conveying accuracy are further improved. In particular, by setting the belt tooth height / pulley groove depth to be more than 1.00 and less than or equal to 1.20, the gap between the belt tooth groove and the tip of the pulley becomes large,
By increasing the position of the center line of the rotation of the belt on the pulley, the polygonalization of the belt is alleviated, and the position of the center line of the rotation does not fluctuate much up and down, thereby minimizing the speed fluctuation rate.

In particular, the above-mentioned belt tooth portion height / pulley groove depth is applied in a range of more than 1.00 to 1.20, and when the belt and the pulley are completely engaged, the belt teeth are compressed in the height direction. The belt teeth expand, the gap between the belt pulleys is completely eliminated, the belt teeth do not move on the pulleys, and the center line of the pulley groove and the center line of the belt teeth substantially coincide with each other. When the driving of the toothed belt is started, unexpected movement on the pulley, occurrence of runout can be effectively prevented, and the meshing movement of the belt with the pulley can be made smooth. Conversely, the belt can be easily detached from the pulley, and a high-level positioning system in a printing device such as office equipment can be secured. Also, by forming the belt teeth with round teeth having convex arc-shaped side walls and forming the pulley groove with concave arc-shaped groove walls, even if the pulleys constituting the apparatus are relatively small, , Less interference when meshing the belt,
The meshing is easy.

When the tooth thickness W of the belt is the same, the teeth of the round tooth belt of the present invention have a larger area and volume than the teeth of the trapezoidal tooth belt. In the tooth belt, the distortion of the belt teeth is small, and the positioning transmission can be performed with higher precision.

The core of the toothed belt has a diameter of 5 to 9 μm.
E glass or high-strength glass twisted with m filaments, or by using a thin aramid fiber rope consisting of 0.5 to 2.0 mm, the belt itself becomes soft and pliable even at normal temperature and low temperature atmosphere, Because the coefficient of linear expansion of the aramid fiber is minus, -35 to 5 ° C
, The tension at low temperature is reduced, the starting torque can be reduced, the load on the shaft is reduced, and the electric capacity of the small motor can be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1A shows a part of a toothed belt 1 preferably used in the toothed belt driving device of the present invention.
(B) shows a part of the toothed pulley 10 engaged with it. As shown in FIG. 1 (a), a toothed belt 1 used in the present invention has a belt body 1 'made of a rubber-like elastic body, and has a constant pitch in the longitudinal direction of the back surface of the belt body 1'. The tooth portions 2 and the groove portions 3 are formed alternately, and a low elongation and high strength rope tensile body such as glass fiber or aramid fiber is embedded on the pitch line 4 of the belt main body 1 '.
And a belt 1 having a tooth 2 and a groove 3
The back side is continuously and entirely covered with a cover canvas, if necessary.

FIG. 2 is a perspective view showing an outline of the toothed belt 1. In the toothed belt 1, a plurality of core wires 21 extending in the belt longitudinal direction are arranged in parallel with a pitch 22 between the core wires. It is buried, and the tooth surface 25 and the tooth bottom 24 are covered with a tooth cloth 25 such as a cover canvas.

[0019] Then, formed of a part of the arcuate surface of a curvature radius R _B having a center point 5 on稍下side of the pitch line 4 of the teeth 2 in the belt 1 Figure 1 belt body 1 as (a) ' A pair of convex roots 8 formed of a pair of convex circular arc surfaces forming part of the back surface of the belt, and a circular surface drawn with a radius rB having a center point 7 on the outer side of the tooth root 8. And a tooth tip 9 formed with a flat plate surface or a convex arc surface connecting the tip portions of the pair of side walls 6 and 6. Furthermore, the curvature radius R _B to form the side wall 6 of the belt tooth portion is formed equally to the belt tooth thickness W in FIG.

On the other hand, as shown in FIG. 1B, the pulley 10 meshing with the toothed belt 1 has a pulley tooth portion 11 formed of an arc surface of a radius rP having a center point 12 inside a tooth tip 13 thereof. Tip part 13 and tip part surface part 14 formed by curve
(Where rP <rB) and below the pitch line 4 of the belt body 1 'of the toothed belt 1 meshed and mounted on the pulley 10 and directly below the center point 5, that is, the center of the pulley. And a pair of concave-shaped arcuate pulley groove walls 16 which constitute a part of the peripheral surface of the pulley, and which comprises a part of an arc surface having a radius of curvature Rp having a center point 15 located on the part direction side. The pulley groove portion 18 includes the pair of pulley groove walls 16 and 16 and a groove bottom portion 17 formed by a flat plate surface or an arcuate surface of a ridge connecting between the pair of pulley groove walls 16.

When the toothed belt 1 having the above-described round teeth is mounted on the pulley 10, the length of the curvature radius Rp forming the groove wall 16 of the pulley is determined by the curvature for forming the side wall 6 of the tooth portion 2 of the belt. smaller than the length of radius R _B, or equal to, in some cases, or opposite large is set to the configuration of the belt tooth portion 2 or the pulley groove 18, by selection of the shape, these curvature radii Rp, Rb its seasons change I'm sullen.

Thus, the root 8 of the belt is shifted to the tip 13 of the pulley.
, Or there is a slight backlash, and the backlash is configured to gradually increase from the root 8 to the tip 9 of the belt.

In the present invention, however, it has been found that in the toothed belt driving device as described above, the ratio of the belt tooth height to the pulley groove depth plays an important role in the speed fluctuation rate. Height / pulley groove depth is set in a range exceeding 1.00 and not more than 1.20.

FIGS. 3 (a), 3 (b) and 3 (c) show the difference in the static meshing state when the ratio between the pulley groove depth and the belt tooth height is changed. FIG. When the pulley groove depth and the belt tooth height are the same, (b) shows that the pulley groove depth is 95% of the belt tooth height, that is, the belt tooth height / pulley groove depth ≒ 1 used in the present invention. .052, (c) indicates that the pulley groove depth is 80, which is the belt tooth height.
%, Ie, belt tooth height / pulley groove depth = 1.25.

[0025] When wound around the pulley by the pulley groove depth as shown (b) is shallower than the conventional, the clearance S of the belt tooth space and the pulley tooth tip is increased and S → S _1,
By increasing the position of the center line of rotation of the belt on the pulley, polygonization is reduced, and the position of the center line of rotation does not fluctuate much up and down, so that the speed fluctuation rate is reduced.

As shown in FIGS. 4A to 4D,
When torque is applied, the belt is compressed in the height direction, the belt teeth expand, the gap with the pulley is completely eliminated, the belt teeth do not move, and the center line of the pulley groove and the center line of the belt teeth substantially coincide. The belt teeth which are centered in the state and then mesh with each other mesh with the center of the next groove of the pulley as shown in FIGS. 4 (b) to 4 (d), so that mesh interference hardly occurs.

On the other hand, if the belt tooth height / pulley groove depth exceeds 1.2 as shown in FIG. 3C, the gap becomes S ₂ , and the contact area between the belt and the pulley becomes too small.
The transmission force of the belt teeth decreases, and jumping occurs.
Accordingly, it is effective that the ratio of the height of the belt teeth / the depth of the pulley groove is more than 1.00 and not more than 1.20 shown in FIG.

The rubber-like elastic body constituting the belt body 1 'and the teeth 2 used in the present invention is, specifically, chloroprene rubber, natural rubber, millable urethane rubber, hydrogenated Rubbers such as nitrile rubber, chlorosulfonated polyethylene (CSM), and alkylated chlorosulfonated polyethylene (ACSM) are preferred.
The hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and preferably 90% or more in order to exhibit heat resistance and ozone resistance. A hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance.
In the rubber, as a compounding agent, carbon black, zinc white, stearic acid, a plasticizer, an antioxidant, and the like are added, and as a vulcanizing agent, there are sulfur and organic peroxides.
These compounding agents and vulcanizing agents are not particularly limited.

On the other hand, the canvas used for the tooth cloth 25 is 6 nylon, 66 nylon, polyester, aramid fiber or the like, and these may be used alone or in combination. The configuration of the warp (belt width direction) or the weft (belt length direction) of the tooth cloth 25 is also a filament yarn or a spun yarn of the fiber, and the weave configuration may be any of a plain woven fabric, a twill woven fabric, and a satin woven fabric. In addition, it is preferable to partially use a stretchable wooly nylon yarn, urethane elastic yarn, or a mixed twist of urethane elastic yarn and nylon as the weft.
In particular, in the case of plain woven canvas, the weft and the warp are alternately vertically crossed and laminated, so that the wave-shaped intersections of the weft and the warp are continuously formed in the weft and warp directions. On the other hand, when twill weave and satin weave canvas are used, the weft and the warp each form an intersection in a wavy shape at every other direction, the number of wavy intersections is smaller than that of a normal plain weave canvas, and the rubber is not only between the yarns but also between the yarns. It is preferable to sufficiently penetrate between the intersections and use this for the belt corrugated portion, because the warp and the weft in the belt flexibility can avoid direct contact with each other and improve the belt life.

The tooth cloth 25 is mainly treated with a resorcinol-formalin-latex liquid (RFL liquid). R
The FL liquid is obtained by mixing a latex with an initial condensate of resorcinol and formalin. The latex used here is a styrene / butadiene / vinylpyridine terpolymerization resistant, hydrogenated nitrile rubber, chlorosulfonated polyethylene, Latex such as epichlorohydrin.

In the present invention, the tooth cloth 25 is treated only with the RFL solution, and the fixed amount of the resorcin-formalin resin is adjusted to 20 to 50% by weight, so that the opening of the tooth cloth 25 is small, and The rubber of the tooth portion is not exposed from the surface because it is difficult to expand, and the scattering of the rubber powder can be prevented. In addition, the solid content of the resin adhered to the tooth surface lowers the frictional resistance of the surface, and reduces noise during belt driving.

The aramid fiber rope used as the core wire 21 is usually composed of a filament group in which 100 to 400 monofilaments of 0.5 to 2.0 denier are converged as strands.
After aligning ~ 3 pieces, it is one-twisted with a twist of 0 to 100 times / 10 cm, and usually has a diameter of 0.10 to 0.20
mm. Here, when the monofilament is less than 0.5 denier, the rigidity is reduced, but the modulus is also reduced, belt elongation occurs, printing accuracy and transport accuracy are deteriorated, and costs are increased. Beyond 0 denier, the rigidity of the belt increases due to lack of flexibility.

Further, when the diameter of the rope is less than 0.10 mm, the modulus becomes low and belt elongation occurs.
Also, the PLD value of the belt becomes too low, the engagement with the pulley becomes long, and the printing accuracy or the transport accuracy deteriorates. On the other hand, if it exceeds 0.20 mm, the rigidity of the belt is reduced due to lack of flexibility, and the starting torque also increases.
It is preferable to use in the range of ０．２0.20 mm. Also,
The inter-core pitch 22 is preferably set to 0.2 to 0.5 mm. If the inter-core pitch is less than 0.2,
At the time of belt production, the cords become heavy and cannot be produced. On the other hand, if it exceeds 0.5 mm, the belt modulus becomes low, belt elongation occurs, and printing accuracy or conveyance accuracy deteriorates.

The aramid fiber used for the core wire 21 is an aramid having an aromatic ring in the main chain of the molecular structure, for example, trade names such as Conex, Nomex, Kevlar, Technora, and the like.
Twaron and the like.

In addition to the aramid fiber rope, glass fiber can be used for the core wire 21. E glass or high-strength glass obtained by twisting filaments having a diameter of 5 to 9 μm is used.

[0036]

Embodiments of the present invention will be described below.

Belt size: 210ST1.0-6.4
(Round tooth belt, tooth pitch 1.0mm, number of teeth 210,
6.4 mm wide belt), 20 pulley teeth, 80 denier 6 nylon warp and 80
It is a weft made of 6 denier nylon and has a warp density of 250.
After weaving with a twill cloth at a weft density of 300 (books / cm) at a weft density of 300 (books / 5 cm), the fabric is vibrated in water to shrink to about 1/2 the width of the weaving, and then the fabric is RFL liquid And squeezed onto a pair of rolls at 0.5 kgf / cm (gauge pressure), followed by drying to obtain a tooth cloth. The solid content adhering material of the resin of the tooth cloth is [the weight of the treated cloth minus the weight of the untreated cloth]
/ [Untreated canvas weight] x 100 (%)
It was 0%.

Next, a non-twisted multifilament strand is prepared as a core wire in which a predetermined number of aramid fiber filaments (commercial surface technolas) are arranged in a predetermined number, and this single strand is twisted 40 times / A 10 cm rope is twisted (single twist) to obtain a rope having a diameter of 0.15 mm, and a twisted rope is prepared using a pair of S and Z. The twisted rope is immersed in an adhesive made of an RFL solution, and dried. Obtain a treatment rope, and apply a core pitch of 0.31 mm and a tension of 1.0 kg
/ Book alternately wound.

Using the rubber elastic belt manufactured as described above, the ratio between the belt tooth height and the pulley groove depth was changed.
Rotation speed 450r. p. m was tested. That is, FIG.
Drive-side pulley 2 using speed fluctuation rate measuring device 27 shown in FIG.
8 and the driven pulley 29, the driven pulley 29 is moved to apply tension, a predetermined axial load is applied to the belt, and then the drive pulley 28 is set at 450 rpm.
p. m, and confirm that the dynamic shaft load has reached a predetermined value (2 kgf). After the shaft load has stabilized at a predetermined numerical value, the speed unevenness is measured by the speed unevenness measuring device 30 and the FF is measured.
At T31, the speed fluctuation rate (wow and flutter) was calculated to measure the speed fluctuation rate.

In the figure, reference numeral 32 denotes a sensor. As a speed unevenness measuring device for measuring the speed fluctuation rate, a non-contact speed unevenness measuring device utilizing the Doppler effect of a laser beam was used. The speed fluctuation rate is defined by the following equation as a percentage of the fluctuation amount ΔV of the rotation speed with respect to the average rotation speed V ₀ . Speed fluctuation rate (Wow and flutter) = (ΔV / V ₀ ) × 10
0 (%) FIG. 6 shows the result of measuring the speed fluctuation rate between the belt and each pulley according to the above.

Next, the number of teeth of the pulley is reduced to 30, 40 in the same manner.
And the speed fluctuation rate was measured in the same manner. The results are shown in FIGS. 7 and 8. In the figure, continuous circles indicate standard products having the same ratio of belt tooth height to pulley groove depth, and black squares indicate belt tooth height and pulley groove depth of 1.
The reference numeral 052 indicates a comparative example in which the height of the tooth portion of the belt / the depth of the pulley groove is 1.25, and the speed fluctuation of the black square according to the present invention from the above figures. The ratios are lower than those of the others, and it can be seen that the toothed belt driving device according to the present invention is excellent in the printing accuracy and the transport accuracy. Especially when the ratio is 1.
In the case of No. 25, the behavior of the belt became unstable and the result was worse than that of the standard product. The meshing state between the belt and the pulley in this case is as shown in FIG. 3B, and shows a smooth meshing state with little interference between the belt tooth side surface and the pulley groove side surface. The smoothness of the meshing is a factor contributing to a reduction in the speed fluctuation rate.

On the other hand, the tooth pitch of the toothed belt is 2.032 mm pitch, 1.5 mm pitch, 1.0 mm
The condition of each pitch and the speed fluctuation rate were observed respectively in place of the pitch. As shown in FIGS. 9A, 9B, and 9C, the result is 1.5 mm or less.
It is found that the speed fluctuation rate is much smaller, with both 1.0% and 0.3% being low, whereas the figure in FIG. .

Further, the driving pulley rotation speed of the belt and the pulley is set to 1200 rpm. p. m, and the number of pulley teeth and the speed variation were observed. As a result, as shown in FIG. 10, in the case of using the shallow tooth groove pulley in the present invention, the speed variation rate is smaller than that of the conventional pulley, and the number of teeth is more advantageous than the number of teeth. It was found that there was. In the drawings, black marks indicate shallow tooth groove pulleys (belt tooth height / pulley groove depth = 1.05) in the present invention, and white marks indicate conventional pulleys (belt tooth height / pulley groove). Depth = 0.95).

[0044]

As described above, the toothed belt driving apparatus according to the present invention has a belt tooth height and a pulley groove depth in the toothed belt and the pulley groove which are larger than those of the latter, and are 1.00 to 1.2.
By setting the pulley groove portion to be shallow as 0, the tooth tip of the belt and the groove bottom of the pulley are brought into contact with each other. When the belt and the pulley engage, the belt teeth are compressed in the height direction to expand the belt teeth, thereby causing the belt tooth to expand. Since there is no gap and the belt tooth does not move on the pulley and the center line of the pulley groove and the center line of the belt tooth are substantially aligned, the completely meshed teeth are compressed and centered, and The meshing of the belt teeth does not shift to the next tooth of the pulley without fail, making it less likely to cause interference, and even if there is an error in the single pitch of the belt, it is less likely to interfere. Since the line is close to a circle, the speed fluctuation is suppressed low, and the speed fluctuation rate can be made smaller than in the past, so that the printing accuracy and the conveyance accuracy can be dramatically improved.

The driving apparatus according to the present invention is applied to a belt having a structure in which the backlash amount is temporarily increased as the belt root approaches the belt tooth tip from the root of the belt. Unexpected movement and run-out can be effectively prevented, and the meshing movement of the belt with the pulley can be made smooth. On the contrary, the belt can be easily detached from the pulley. With this, it is possible to secure a high degree of positioning accuracy in a printing device of office equipment represented by a typewriter, a printer, etc., and the belt teeth are formed of round teeth having convex arcuate side walls. By forming the pulley groove portion with a concave arc-shaped groove wall, even when the pulley constituting the apparatus is relatively small, interference during belt engagement is small, and engagement is impossible. Succoth can. Moreover, by setting the tooth pitch of the toothed belt to 2.5 mm or less, it is possible to further reduce the speed fluctuation rate.

Further, as a core wire, a bundle of at least one or more filaments in which aramid fibers composed of 0.5 to 2.0 denier monofilaments are bundled is bundled into a single twist to form a thin filament having a diameter of 0.10 to 0.20 mm. By using an aramid rope or one of E glass or high-strength glass in which filaments having a diameter of 5 to 9 μm are twisted, and by setting the pitch between cords to 0.2 to 0.5 mm,
Even in a low-temperature atmosphere, the belt itself is soft and pliable, and has low elongation.In particular, since the aramid fiber has a negative coefficient of linear expansion, the tension at low temperatures is reduced, and the starting torque can be reduced, and the shaft can be reduced. And the electric load of the small motor can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a belt tooth portion and a pulley groove portion of a toothed belt driving device according to the present invention, wherein FIG.
(B) shows a pulley groove.

FIG. 2 is a perspective view of a main part of the toothed belt according to the present invention.

3A and 3B are diagrams showing a difference in a static engagement state due to a difference in a pulley groove depth of the toothed belt driving device according to the present invention, wherein FIG. 3A is a standard product, FIG. ) Is a comparative product.

4 (a) to 4 (d) are diagrams showing engagement between a shallow tooth groove pulley and a belt tooth portion of the toothed belt driving device according to the present invention.
Are in a meshing state sequentially.

FIG. 5 is a diagram showing a toothed belt speed variation rate measuring device according to the present invention.

FIG. 6 is a comparison chart of pulley speed fluctuation rates when the belt tooth height / pulley groove depth is changed in the case of 20 pulley teeth.

7 is a pulley speed variation comparison chart similar to FIG. 5 in the case of 30 pulley teeth.

FIG. 8 is a pulley speed variation comparison chart similar to FIG. 5 when the number of pulley teeth is 40;

FIGS. 9A and 9B show a comparison of speed fluctuation rates when the tooth pitch is changed in the present invention, wherein FIG.
(B) is for a 1.5 mm pitch, and (c) is for a 1.0 mm pitch.

FIG. 10 is a comparative chart showing the relationship between the number of pulley teeth and the speed fluctuation rate.

FIG. 11 is a reference diagram showing a meshing state between a belt tooth portion and a pulley groove of a conventional toothed belt driving device.

FIG. 12 shows the meshing state between the pulley teeth and the belt teeth when the speed fluctuation rate is large, and (a) to (d) show the meshing state sequentially.

[Explanation of symbols]

1 toothed belt 1 'belt body 2 belt tooth portion 4 pitch line 5 radius of curvature R center point 8 tooth root 9 tooth tip 10 pulley 11 pulley teeth 12 of curvature of the center point 6 the belt tooth portion side wall 7 of curvature radius r _B of _B The center point of the radius r _P 15 The center point of the radius of curvature R _P 16 The groove wall of the pulley 17 The groove bottom of the pulley 18 The groove of the pulley W The tooth thickness of the belt

Claims (7)

[Claims] 1. A driving device in which a toothed belt is wound around at least a pair of toothed pulleys to perform a reciprocating motion or a one-way motion, and a depth of a pulley groove portion of the toothed pulley is measured by measuring a linear shape. The belt tooth height is smaller than the tooth height, and the belt tooth height / pulley groove depth is more than 1.00 and less than 1.20. When the belt and the pulley are completely engaged, the belt teeth move in the height direction. The belt tooth is expanded by being compressed, the gap with the pulley is completely eliminated, and the belt tooth does not move on the pulley, and the center line of the pulley groove and the center line of the belt tooth substantially coincide with each other. Toothed belt drive. 2. The belt tooth and the pulley groove which are completely meshed with each other substantially coincide with each other in center, so that the belt tooth and the pulley groove which are next meshed with each other also substantially coincide with each other, and the belt teeth are engaged with the pulley groove. 2. The toothed belt drive according to claim 1, wherein at the beginning, the belt teeth start contacting only at a position below the half depth on the side surface of the pulley groove. 3. A tension member is buried on a pitch line of a belt body formed of an elastic body, and teeth are ridged at a constant pitch on a back surface side of the belt body to form a part of the back surface of the belt. The toothed belt has a toothed belt formed with a convex arcuate surface on the side wall and a toothed pulley formed with a concave arcuate grooved wall of a circumferential groove group. In a typical meshing state, the tooth tip of the belt tooth part is in contact with the tooth bottom of the pulley groove part, and the backlash between the belt tooth part and the pulley groove is configured to gradually increase from the belt root to the tooth tip side, 3. The toothed belt driving device according to claim 1, wherein a depth of the pulley groove is smaller than a height of the belt teeth. 4. In a toothed belt driving device, a core wire embedded in a belt body of a toothed belt to be used is set to 0.1.
An aramid fiber rope obtained by bundling and twisting at least one filament group in which aramid fibers composed of monofilaments of 5 to 2.0 deniers are converged,
4. The toothed belt driving device according to 2 or 3. 5. The toothed belt driving device, wherein the core wire embedded in the belt body of the toothed belt to be used is one of E glass or high-strength glass in which a filament having a diameter of 5 to 9 μm is twisted. 4. A toothed belt drive according to claim 1, 2 or 3. 6. The toothed belt driving device according to claim 4 or 5, wherein the pitch between the cores of the toothed belt to be used embedded in the Behart main body is in the range of 0.2 to 0.5 mm. The toothed belt driving device as described in the above. 7. A driving device in which a toothed belt is wound around at least a pair of toothed pulleys to perform a reciprocating motion or a one-way motion. Tooth height / pulley groove depth is 1.
When the belt and the pulley are completely engaged with each other, the belt tooth is compressed in the height direction, so that the belt tooth expands and the gap between the belt and the pulley is completely eliminated. The belt tooth does not move, and the center line of the pulley groove coincides with the center line of the belt tooth, so that the next meshing tooth of the belt meshes with the center of the pulley groove so that they coincide substantially, and the pulley groove of the belt tooth At the beginning of meshing, the belt teeth are
2. A toothed belt drive as claimed in claim 1, wherein contact only starts at a position below a depth of / 2.