JP2014163738A - Positioning mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that since the hitherto known positioning mechanism has a shape of a portion in contact with a follower wheel which is set in a bilaterally symmetrical shape, a rotation load in a forward direction and a reverse direction is substantially the same, and thus it is difficult to simply establish convenience by a positioning mechanism alone that a driving in the forward rotation side makes a load as much as small and the reverse rotation side performs a positioning with much stronger force.SOLUTION: The positioning mechanism includes a rigid part for performing a positioning of a follower wheel. A contacting relationship between this rigid body and a follower gear provided in the follower wheel is configured such that a length of an arm of moments of a force which rotates the rigid body is extremely long in the forward direction relative to the reverse direction, and a load of the gear toward the rotational direction is small relative to the reverse direction. The rigid body of the positioning mechanism sets angle α formed by a perpendicular component of a tangent line of a point at which a vertex of the rigid body and the follower gear comes in contact with each other and a component toward a rotational center direction of a contact point with the follower gear of the vertex of the rigid body to equal to or more than 0°, and when a strong shock is applied, the rigid body acting as a reverse rotation preventive mechanism prevents a damage of detached components.

Description

The present invention relates to a structure of a step motor used as an electromechanical converter of a pointer type electronic timepiece. More specifically, the present invention relates to a positioning mechanism used for an oscillating step motor or the like in which an output gear is driven by a predetermined angle per reciprocation while a rotor reciprocates with a predetermined angular amplitude.

A step motor composed of a permanent magnet magnetized in two poles, a two-pole stator, and a one-phase coil, which is generally used in a pointer type electronic timepiece, energizes the coil once per second. The rotor is driven and rotated 180 degrees to drive the train wheel connected to the second, minute, and hour hands, and has achieved considerable success in reducing power consumption and operational reliability. In such a pointer-type electronic timepiece, the second hand is moved once per second. However, some clock users, like mechanical clocks, have a continuous hand that seems to move and move (sometimes referred to as a sweep hand. With intermittent hand movements of several to several times per second. There is a group that likes it), and its demand is increasing in recent years.

  Satisfying such a requirement using a general step motor can be realized once the driving time interval is shortened and the reduction ratio up to the second hand is increased. However, the rotor has an inertia ratio that cannot be ignored, and it is accelerated every time it is driven to drive the train wheel. However, since the excess kinetic energy is discarded in the process of the rotor's free damping vibration, the frequency of driving increases. The ratio of wasted energy is increased, and the power battery is consumed quickly.

  Among these pointer-type electronic timepieces that perform such continuous hand movements, especially wristwatches must be equipped with large batteries in order to have a sufficient battery life, and this is a great way to reduce the size and thickness of watches. There was a problem. In addition, a power generation mechanism such as a solar battery may be mounted in order to eliminate the need for battery replacement. However, as described above, in the case of continuous operation using a general step motor, power consumption is large, so that it can be mounted on a wristwatch. In the power generation mechanism, power supply is not sufficient, and in order to realize a battery non-exchangeable wristwatch, it is necessary to mount a large-capacity large-sized battery.

  Patent Document 1 is a swinging step motor for driving two driven vehicles engaged with each other by a rotor having a feed claw portion. A reverse rotation stopping claw lever is arranged as a reverse rotation prevention and positioning mechanism for the driven gear driven by the rotor claw. This is necessary when the driven vehicle rotates when the rotor rotates due to the pulse applied to the coil. At this time, the rotor rotates to a place where the pulling force and the applied energy are balanced and stops, and the driven gear is returned by the pulling force at the next moment. The phenomenon that the gear is returned is a problem that must be removed in order to induce a misstep and perform stable operation. In order to avoid this, the reverse rotation stop lever is adjusted and the driven gear is positioned so that the stop position of the driven vehicle driven by the rotor becomes the stable operating point.

Japanese Patent Application Laid-Open No. 55-20461 (FIGS. 1 and 2)

However, the conventional technique shown in Patent Document 1 has the following problems. The driven vehicle driven by the claw feed takes a stable position by the positioning mechanism, but the shape of the portion where the positioning mechanism is in contact with the driven vehicle is set to be a substantially symmetrical shape, and rotates in the forward and reverse directions. The load was almost the same. Since the load at the time of rotating in the forward rotation direction in which the load is originally desired to be reduced increases, extra power consumption is required. Therefore, it is very difficult to simply set the contents of a relationship that is difficult to achieve both by reducing the load as much as possible on the forward rotation side and positioning with a stronger force on the reverse rotation side using only the positioning mechanism. It was.
In addition, in order to stop the driven vehicle at an appropriate stable position, it is necessary to adjust the position of the positioning mechanism according to the variation of the parts, and there is also a point that the variation from product to product occurs due to the operator's familiarity and differences between people. It is a problem.
It is an object of the present invention to provide a positioning mechanism for a stepping motor for continuous hand movement that performs positioning of a driven vehicle rotated by a rotor with a low load, enables stable operation and low power consumption, and does not require position adjustment. Objective.

The present invention relates to a positioning mechanism, wherein a converter is composed of a coil, a rotor, and a stator, and the rotor has a cam portion and drives two meshed driven gears. The present invention relates to a positioning mechanism applicable to the above.

  More specifically, the oscillating step motor is an oscillating step motor in which the output gear is driven by a predetermined angle for each reciprocation while the rotor reciprocates with a predetermined angular amplitude.

  The two gears meshed with each other are arranged symmetrically with respect to the rotor cam, and one of them has a gear positioning mechanism. This positioning mechanism rigid body portion may be arranged on both sides of the driven vehicle. The installed rigid body is pressed against the driven gear by an elastic member. In the present embodiment, the elastic member and the rigid part are formed as separate parts, but the part may have an elastic body in a part of the rigid part.

In the present invention, the rigid body portion for positioning the driven vehicle is provided, and the relationship between the rigid body portion and the driven gear installed in the driven vehicle is that the length of the arm of the moment of force for rotating the rigid body portion is L1. <L2, and the length of L2 is very large with respect to L1, and the load in the rotational direction of the gear is small in the reverse direction.
In the rigid body portion of the present invention, the angle α formed by the component from the contact point between the vertex of the rigid body and the driven gear at the point where the driven gear contacts and the driven gear at the vertex of the rigid body portion toward the rotation center is set to 0 ° or more. It is set. By adopting such a setting, when a strong impact is applied, the rigid body portion that worked as the reverse rotation prevention mechanism is detached to prevent damage to the parts.

The side surface of the positioning mechanism rigid body portion is inclined at three different angles.
By having this three-stage surface, it is possible to reduce the load when working as a positioning mechanism when the rigid body part is pushed up by the rotation of the driven vehicle and to use in a region where the rotation transmission of the rotor is high, thus reducing power consumption. It is.

By using the positioning mechanism having such a configuration, it is possible to position the driven gear while reducing the load in the forward rotation direction, and thus it is possible to perform a stable operation with lower power consumption than in the past.
At the same time, with respect to the movement in the reverse direction, the rotation load is heavy and the light cannot be reversed when a light impact is applied, so that the needle is not displaced with respect to the impact.
Furthermore, when a strong impact is applied and the driven vehicle is rotated in the reverse rotation direction, the positioning mechanism portion pressed against the driven gear is detached, and the parts are not damaged. Therefore, a thin part with less resistance can be used for the rotating part (specifically, the shaft part) of the positioning mechanism part, and it is possible to reduce the power consumption and to achieve a highly durable mechanism. Become.

Overall view for explaining the overall configuration of a swing type step motor having a positioning mechanism of the present invention (configuration diagram of an embodiment) Detailed sectional view of sectional line A shown in FIG. 1 (configuration diagram of the embodiment) A diagram describing the arm length of the moment of force for rotating the rigid body portion when the angle α formed at the contact point of the positioning mechanism rigid body portion with the driven gear is α> 0 and rotation is performed (embodiment explanatory diagram) Detailed enlarged view of the surface where the rigid body portion of the positioning mechanism contacts the driven gear (embodiment explanatory drawing) Diagram showing the length of the arm of the moment of force for rotating the rigid body portion when the angle α formed at the contact point of the positioning mechanism rigid body portion with the driven gear is α ≦ 0 and rotating (embodiment explanatory diagram) Magnification detail view when positioning mechanism rigid body part composed only of 301c surface contacts driven gear Magnification detail view when positioning mechanism rigid body part composed only of 301c surface and 301b surface is in contact with driven gear Implementation drawing when the balance weight part is placed on the rigid part of the positioning mechanism

A configuration of the swing type step motor in which the positioning mechanism of the embodiment is arranged will be described.
FIG. 1 is a plan view showing a main part of the present embodiment.
The motor body includes a coil, a stator (not shown), and a rotor 5, and the rotor 5 has a cam portion 501 and drives two driven vehicles 4 </ b> A and 4 </ b> B engaged with each other.

  The driven wheels 4A and 4B are structured such that the driving wheels 401A and 401B meshing with each other and the gears 402A and 402B driven by the cam portion 501 of the rotor 5 are fitted to the shafts 403A and 403B, respectively, and rotate around the shaft 403. (See FIG. 2). The driven vehicles 4A and 4B meshing with each other are arranged symmetrically with respect to the rotor cam 501, and the rotor cam 501 swings and sequentially sends the gears 402A and 402B, whereby the driven vehicle 4A is moved in the direction of the arrow c. The driven vehicle 4B is sent in the direction of arrow d. The driven vehicle 4B drives a train wheel for driving a pointer (not shown), but details thereof are not an essential part of the present invention, and thus detailed description thereof is omitted.

One driven vehicle 4 </ b> A has a gear positioning mechanism 3.
The positioning mechanism 3 includes a positioning mechanism rigid body portion 301 that contacts and presses against the driven gear 402 </ b> A and a positioning mechanism rotation shaft 302 having a rotation center o. The positioning mechanism rigid body portion 301 is fitted to the positioning mechanism rotation shaft 302. . Reference numeral 1 denotes an elastic member that is in contact with the positioning mechanism rigid body portion 301 and applies a force to press the positioning mechanism rigid body portion 301 against the driven gear 402A. Normally, the position of the positioning mechanism rigid body 301 is maintained by the pressing force of the elastic member 1. Reference numeral 2 denotes an elastic member fixing portion 2 for fixing the elastic member to, for example, a train wheel bridge 8 and a main plate 9 described later.
In this embodiment, the elastic member 1 is a leaf spring, but any member may be used as long as it provides a pressing force (biasing force).

Reference numeral 7 denotes a mechanism rotation restricting member that restricts the rotation of the positioning mechanism rigid body portion 301. The positioning mechanism rigid body 301 and the mechanism rotation restricting member 7 are normally separated from each other. However, when a large force is applied by an impact or the like, the positioning mechanism rigid body 301 and the driven gear 402A are disengaged, and the positioning mechanism rigid body When the part 301 rotates in the arrow e direction opposite to the urging direction, the rotation is restricted, and the positioning mechanism rigid body part 301 is prevented from excessive rotation and deformation of the elastic member 1.
In the present embodiment, the mechanism rotation restricting member 7 has a cylindrical shape, but the shape thereof is not limited.

FIG. 2 is a cross-sectional view of the cross-sectional line A shown in FIG. 1 and is a main component of the present invention. The positioning mechanism 3 is pivotally supported by bearings 801 and 901 installed on the train wheel bridge 8 and the main plate 9. The positioning mechanism rigid body portion 301 of the positioning mechanism 3 is in contact with the driven gear 402 </ b> A by the elastic member 1. Even during normal operation (during forward rotation), the driven gear 402A rotates and a load is generated when the tooth tip lifts the positioning mechanism rigid body 301. Therefore, the sliding portion of the positioning mechanism rotating shaft 302 serving as the rotating shaft of the positioning mechanism 3, specifically, the bearing portions 302a and 302b supported by the bearings 801 and 901 reduce friction caused by the rotating operation. Therefore, the diameter is reduced as much as possible to reduce the frictional resistance.
Reducing the resistance during rotation of the positioning mechanism 3 can reduce the load for rotating the driven vehicles 4A and 4B, leading to lower power consumption.

  As is clear from FIG. 2, the positioning mechanism 3 has a high center of gravity, so it is very easy to fall down and difficult to incorporate. Therefore, since the positioning mechanism 3 and the elastic member 1 are arranged close to each other, a part of the elastic member fixing portion 2 is extended to the positioning mechanism 3, and a hole 2a for the positioning mechanism 3 is installed. The positioning mechanism 3 is inserted into 2a. Thus, the elastic member fixing portion 2 has a structure that not only fixes the elastic member 1 but also serves to prevent the positioning mechanism rotating shaft 302 (that is, the positioning mechanism 3) from falling. By providing the elastic member fixing portion 2 with a function of preventing the collapse, the ease of assembly can be improved without additional parts.

In the present embodiment, the hole 2a is installed in the elastic member fixing portion 2 to prevent falling, but the falling preventing member may be a separate part.
Moreover, even if it is not the hole 2a, you may prevent a fall by making it the structure which encloses the positioning mechanism 3 so that it may not fall in the elastic member fixing | fixed part 2. FIG.

  Power is transmitted to the driven gears 4A and 4B by the rotor cam 501, but the driven gears 4A and 4B may be rotated in a direction opposite to the normal rotation direction c of the driven gear due to an impact or the like. If the driven gears 4A and 4B rotate in the reverse rotation direction, the drive transmission start position between the rotor cam 501 and the driven gears 4A and 4B greatly deviates from the appropriate position, causing the mesh transmission efficiency to deteriorate and the rotational load of the rotor 5 to increase. Therefore, power consumption increases. In order to perform low power consumption and stable operation, it is necessary to regulate the reverse direction so that the position of the driven gear 4A does not return more than necessary. Therefore, the positioning mechanism rigid body portion 301 is mainly intended for positioning the driven gear 4A, but not only the positioning of the driven gear 4A in the normal rotation direction c but also the driven gear 4A is rotated in reverse by an impact or the like. If this happens, it also functions as a reverse operation prevention mechanism.

  Usually, in order to obtain the effect of preventing reverse rotation, the force of the elastic member 1 is increased as in the prior art of Patent Document 1, and the pressing of the driven vehicle 4A by the positioning mechanism rigid body 301 is increased. Conceivable. However, in this case, not only the reverse rotation direction but also the amount of pressing of the driven gear in the normal rotation direction c increases at the same time, and it is necessary to increase the energy for rotating the driven gear 4A. Will have to be used in a state where the remarkably rises. A structure that solves the problem will be described with reference to FIGS.

  FIG. 3 is an enlarged plan view showing a contact state between the positioning mechanism rigid body portion 301 and the driven vehicle 4A, and FIG. 4 is a plan view further expanding the contact portion between the positioning mechanism rigid body portion 301 and the driven vehicle 4A in FIG. FIG.

Even when a load factor such as an impact is applied from the outside as shown in FIG. 3 and the driven vehicle 4A reversely moves in the direction of the arrow f (the state indicated by the solid line in FIG. 3), the pressing force of the elastic member 1 The positioning mechanism rigid body portion 3 is located between the teeth of the driven gear 402A of the driven vehicle 4A, the apex portion 301A where the driven gear 402A and the positioning mechanism rigid body portion 301 are in contact, and the side surface where the driven gear 402A and the positioning mechanism rigid body portion 301 are in contact. The above problem was solved by adopting a configuration in which the reverse operation of the driven gear 402 is prevented by entering the portion 301B so as to be asymmetrically contacted between the two points.
That is, at the time of reverse rotation, the teeth of the driven gear 402A are stopped by the apex portion 301A and cannot be rotated any further, thereby preventing the driven vehicle 4A from rotating in the reverse rotation direction.

  The above description will be described using the rotational moment. In FIG. 3, L2 is the length of the arm of the moment of force for rotating the positioning mechanism rigid body portion 301 when the driven vehicle 4A is driven to rotate forward, and L1 is the length of the arm of the moment of force at the time of reverse rotation. It is.

  In the present embodiment, the length of the arm of the moment of force for rotating the positioning mechanism rigid body portion 301 is L1 <L2, and the length of L2 is very large with respect to L1, and the length of the driven gear 402A is normal. The load in the rotation direction c has a very small load in the reverse rotation direction, and the rotational energy in the normal rotation direction c of the positioning mechanism 3 can be reduced, so that power consumption can be reduced.

  Further, when forces of the same magnitude are input to the driven vehicle 4A, the forward rotation direction is easy to rotate, and the reverse rotation direction is difficult to rotate. Therefore, even when a force is applied in the reverse rotation direction due to an impact or the like, it can be used as a reverse rotation prevention mechanism for the driven vehicle 4A, and not only functions as a positioning mechanism but also prevents the rotation of the driven vehicle 4A in the reverse rotation direction. Therefore, more stable driving is possible.

  The positioning mechanism rigid body 301 and the reverse rotation prevention mechanism for the driven vehicle 4A will be described in more detail with reference to FIG. FIG. 5 is a plan view for explaining the structure conventionally taken.

  Let α be the angle formed by the line segment a that goes vertically from the tangent line of the apex 301A and the line b that is drawn from the contact point of the apex 301A to the positioning mechanism rotation center o. As shown in FIG. 5, the angle α formed when the normal positioning mechanism rigid body portion 3 and the follower vehicle 4A function as a reverse rotation prevention mechanism is set to 0 ° or a negative direction from 0 °, whereby the positioning mechanism rigid body The moment L1 of the arm of the force rotated by the contact point apex 301A and the driven gear 402 between the portion 3 and the driven vehicle 4A is in a state of being bitten by the driven vehicle 4A as the force is applied. If it can be engaged in this way, it can be surely acted as an anti-reverse mechanism, so that it is common to completely lock the driven vehicle 4A by engaging the positioning mechanism rigid body part 3. .

However, if the driven gear 402 is set to bite the positioning mechanism rigid body portion 3, the more the force is applied, the more the positioning mechanism rigid body portion 3 and the tooth portion of the driven vehicle 4A are bitten. It is necessary to consider and reinforce when a big impact is applied to the shaft part and gear tooth part supporting the positioning mechanism rigid body part 3 for biting. Or in the worst case, it will be destroyed. Therefore, in order to prevent a broken state, it is necessary to thicken the bearings 302a and 302b at the rotation center of the positioning mechanism 3 and strengthen the gear itself of the driven gear 402A, but as a result, the sliding load increases and the power consumption increases. End up.
As a result, the positioning mechanism rigid body portion 301 has a problem in that it cannot reduce the sliding shaft or reduce the driven gear tooth portion in order to reduce sliding resistance in order to reduce power consumption. It was.

  The function of the reverse rotation prevention mechanism of the present invention solves the problem of causing sliding loads and component destruction. As shown in FIG. 4, the angle α formed when the positioning mechanism rigid body portion 301 and the driven vehicle 4 </ b> A function as a reverse rotation prevention mechanism is set, but the angle α formed is set to 0 ° or more. Very important. In the present embodiment, the vertex portion 301 where the driven gear 402A and the positioning mechanism rigid body portion 3 are in contact with each other and the line segment a which is perpendicular to the tangent line of the driven gear 402 and the vertex portion 301A where the driven gear 402A and the positioning mechanism rigid body portion 301 are in contact with each other are driven. The reverse rotation is prevented by making the angle α formed by the line segment b drawn from the contact point of the gear 402A to the positioning mechanism rotation center o smaller than the friction angle obtained by the friction coefficient of the driven gear and the rigid body portion. .

The friction angle is an angle at which the object does not slide unless the angle is equal to or larger than the set angle. For example, if the material is a combination of iron, the friction coefficient between parts is generally about 0.2, and the friction angle is calculated to be tan ⁻¹ 0.2 = 11.3 °. At this time, when the positioning mechanism rigid body portion 301 is caused to function as a reverse rotation prevention mechanism for the driven vehicle 4A, the angle α is set to be equal to or smaller than the angle α ≦ 11.3 ° so that the driven vehicle 4A is reversely rotated by a normal light impact or the like. Even when the operation occurs, the follower wheel 4A can be prevented from being reversely rotated because it is equal to or smaller than the predetermined friction angle.

  It has been explained that the anti-reverse function acts on the driven gear 402 for light impacts that are likely to occur frequently in daily use by setting the angle α formed in the positioning mechanism rigid body portion 301. However, strong impact such as dropping is input. In this case, when the driven gear 402A and the positioning mechanism rigid body portion 301 function up to a certain force as the reverse rotation prevention function, the reverse rotation prevention function is released to prevent the parts from being destroyed. This is because the engagement of the positioning mechanism rigid body portion 301 and the driven gear 402A is not in the direction in which the gear meshes with the normal positioning mechanism rigid body portion 3, but in the direction in which the engagement with the positioning mechanism is released, the length of the arm having a moment of L1 By providing a thickness, the positioning mechanism rigid body portion 301 is disengaged from the driven gear when a certain force is exceeded, so that the parts are prevented from being broken.

  Since there is no destruction of the parts even in such a strong impact, there is no need to strengthen the positioning mechanism rotating shaft 302 and the driven gear 402 intensively, and a strong and expensive material or sufficient strength can be provided. Since it is not necessary to make the shaft portion and the tooth portion of the driven gear larger or thicker, it is possible to arrange at low cost and in a small space.

  Since the positioning mechanism rotating shaft 302 and the driven axle 403 can also be made thinner and the sliding resistance during rotation can be reduced, the power consumption can be suppressed as compared with the prior art.

  As a function of the reverse rotation prevention mechanism of the present invention, there is an effect on the operation stability. The stable position of the driven vehicle 4A in the normal rotation direction (arrow c) of the driven vehicle 4A is driven by contacting the driven gear 402A in such a manner that the positioning mechanism rigid body side surface 301B rides up. By positioning the rigid member 3 of the positioning mechanism against the driven gear 402 with a weak force and applying a brake by the elastic member 1, the stop position of the driven vehicle 4A is always stabilized, and a state where the gear is excessively fed is prevented. Thereby, since the driven vehicle 4A is controlled to an appropriate position, the rotor 5 can always drive the driven gear 4A from the condition of the stop position with good transmission efficiency, and wasteful power consumption can be reduced.

Further, since the configuration is such that the driven gear 4A is in a stable position so as to ride on the positioning mechanism rigid body side surface portion 301B, the positioning mechanism is adjusted to a position where the driven gear 4A is desired to be stopped like the positioning mechanism so far. There is no need, and an adjustment process to an appropriate position by an operator is not required at the time of product manufacture. Since there is no need for adjustment, there is no variation in position due to the difference of workers at the time of manufacture, and no time is required for adjustment. Therefore, it is possible to stabilize the product with a certain quality only by incorporating it, and to shorten the manufacturing time.

As shown in FIG. 4, the side surface portion 301 </ b> B of the positioning mechanism rigid body portion 301 has slopes with different angles in three stages of a 301 a surface, a 301 b surface, and a 301 c surface.
Having the three-stage surface configuration in the positioning mechanism rigid body portion 301 reduces the rotational load on the driven vehicle 4A when acting as the positioning mechanism when the positioning mechanism rigid body portion 301 is pushed up by the rotation of the driven vehicle 4A. Since the rotor 5 can be used in a region where the rotation transmission is high, power consumption can be reduced.

  Since the elastic member 1 is in contact with the rigid portion 301, when the surface in contact with the driven gear is configured with a line segment of the 301c surface, or when the line segment configuration includes only the 301b surface and the 301c surface, Compared with the case where the force by which the driven gear is pushed back by the spring force has a 301a surface, a greater moment of force is generated to rotate in the reverse direction. The case where the surface in contact with the driven gear is constituted by the line segment of the 301c surface will be described with reference to FIG. 6, and the case where the line segment constituted only by the 301b surface and the 301c surface will be described with reference to FIG.

  The driven vehicle 4A pushed back by the elastic member 1 is driven at the position where the driven gear 402A and the positioning mechanism rigid body portion 301 are in contact with each other at the apex portion 301A and the driven gear 402A and the side surface portion 301B in which the positioning mechanism rigid body portion 301 is in contact. It becomes the stable position of the car 4A.

  When the driven gear rotates in the normal direction c, the positioning mechanism 3 pressed by the elastic member 1 always generates a force pressing the driven wheel 4A in addition to driving from the rotor 5, and the driven gear 4A is moved in the reverse direction f. Since the force is a force to rotate, the load is constantly acting as a load for lifting the positioning mechanism rigid body portion 301, resulting in an increase in power consumption.

  Therefore, it is necessary to reduce the load so that the driven vehicle 4A is not rotated in the reverse rotation direction as much as possible, and it is necessary to satisfy both contradictory contents of increasing the area in which the positioning mechanism is engaged with the driven gear.

  The complete stable position of the driven vehicle 4A and the positioning mechanism rigid body portion 301 is a position where the driven gear 402A is returned from the position where the driven vehicle 4A is rotated by the rotor 5, and the drive start position of the rotor 5 has transmission efficiency. Since it is necessary to contact the driven gear at a low position and rotate it, the rotor 5 must give more energy than necessary to rotate the driven vehicle 4A. Therefore, it is disadvantageous in terms of power consumption because it must always be driven with extra energy.

  In the positioning mechanism of the present invention, the positioning mechanism rigid body portion 301 is rotated by the rotor 5 by configuring the positioning mechanism rigid body portion 301 with the 301a surface whose pushing back force is smaller in the reverse direction than in the case of the 301b surface, 301c surface and 301b surface. The driven vehicle 4A is configured such that the driven vehicle 4A is unlikely to return in the reverse direction even when the positioning mechanism rigid body portion 301 is lifted, and the driven gear 4A stops and becomes a stable position even when the positioning mechanism rigid body portion 301 is lifted. It was.

  Therefore, when the driven vehicle 4A rotated by the rotor 5 is in a normal rotation operation, the apex portion 301A where the driven gear 402A and the positioning mechanism rigid body portion 301 contact each other, and the side surface portion 301B where the driven gear 402A and the positioning mechanism rigid body portion 301 contact each other. Since it is not returned to the stable position where it touches at two points, it is possible to eliminate the waste of energy for rotation, and the position where the rotor 5 starts feeding can also start to rotate from a position with good transmission efficiency. Become. As a result, it is possible to reduce power consumption when the rotor 5 is rotated.

Also, in the case where the positioning mechanism rigid body portion 301 has a reverse rotation preventing function, 301a
It is effective to have a surface. The case where the positioning mechanism rigid body portion 301 is configured only by the surface 301c will be described in detail with reference to FIG. When the surface in contact with the driven gear 402 is composed of only the 301c surface, the load that pushes up the positioning mechanism rigid body portion 301 by the rotation of the driven vehicle 4A can increase the length of the arm of the moment of force, so that the normal rotation direction c The energy required for rotation can be reduced, but the driven vehicle 4A is moved in the direction of the arrow f by impact or the like and reversely rotated, and the positioning mechanism rigid body portion 301 is stable by the point-to-point contact between the apex portion 301A and the side surface portion 301B. When the position 4A ′ functions as a reverse rotation prevention mechanism, the position of the apex portion 301A where the driven gear and the positioning mechanism rigid body portion contact each other is at the upper portion of the driven gear tooth portion, and the positioning mechanism rigid body portion 301 is the tooth portion of the driven gear 402. The area that works as the reverse rotation prevention mechanism is very narrow because of the small amount of hanging. Accordingly, the accuracy of the parts is extremely required, and it is essential to make the positioning mechanism rigid body material resistant to wear, which is disadvantageous in production.

  FIG. 7 is a detailed view of the case where the positioning mechanism rigid body portion 301 is configured by the 301c surface and the 301b surface. The positioning mechanism rigid body portion 301 is configured with only the surface 301c, and the positioning mechanism rigid body portion 301 has a small amount of toothing with the driven gear 402. The positioning mechanism rigid body portion 301 is configured by the 301c surface and the 301b surface in consideration of increasing the amount of the driven gear 402. However, when the driven vehicle 4A moves in the direction of the arrow f, the positioning mechanism rigid body 301 is prevented from reverse rotation at the stable position 4A ′ by the contact between the apexes 301A and 301B. It functions as a reverse rotation prevention mechanism for the mechanism. Considering the state of working as a reverse rotation prevention mechanism, it is very effective because the amount of the hung on the driven gear 402A increases, but at the same time, the amount that the positioning mechanism rigid body 301 must be lifted by the driven gear 402 also increases. End up. Therefore, the load for turning the rotor 5 that drives the driven vehicle 4A is increased, resulting in an increase in power consumption.

  When the positioning mechanism rigid body portion 301 is configured by the 301c surface and the 301b surface, problems in assembly and manufacturing also occur. The distal end shape of the positioning mechanism rigid body portion 301 has an acute angle, and the distal end is liable to be crushed. Moreover, when manufacturing by press work etc., since it is an acute angle, it is easy to generate | occur | produce a crack etc. in a front-end | tip shape part at the time of manufacture, and is not preferable.

  When the positioning mechanism rigid body portion 301 is configured with only the 301c surface, and when configured with the 301b and 301c surfaces, such a situation can be achieved, but by providing not only the 301b surface 301c but also the 301a surface. Solvable. By providing the positioning mechanism rigid body portion 301 with a 301a surface, it is possible to cause the driven gear 402 to dig deeper than when only the 301c surface is used. Further, since the slope of the 301a surface is gentler than that of the 301b surface as compared with the case of the 301b surface and the 301c surface, the load for lifting the positioning mechanism rigid body portion 301 by the driven vehicle 4A during driving can be reduced, and the power consumption is reduced. An area that can be used as a reverse rotation prevention mechanism can be secured, and both conditions can be satisfied.

Further, the positioning mechanism rigid body portion 301 constituted only by the 301c surface with the 301b surface and the 301c surface has not only the 301b surface 301c but also the 301a surface, which is advantageous in manufacturing.
Since the angles of all the surfaces intersecting with each other are obtuse, it is possible to prevent the occurrence of burrs even when manufacturing with a press or the like, and no special mold is required. In addition, it is possible to secure a sufficient amount of hanging on the driven gear 402A, and it is extremely resistant to variations in accuracy of parts, and has a great production merit.

As shown in FIG. 8, the positioning mechanism rigid body portion 301 can be made stronger against impact by arranging a balance weight portion. Even with the shape of the positioning mechanism rigid portion 301 as in the embodiment shown in FIG. 3, the position can be sufficiently held by the pressing force of the elastic member 1. However, in the shape of the positioning mechanism rigid body portion in FIG. 3, the center of gravity is not located at the rotation center o of the positioning mechanism rigid body portion 301, so that a force for rotating the positioning mechanism 3 is generated when an impact force is applied.

  Since the present invention aims at positioning and prevention of reverse rotation at a low load, it is a portion where the pressing force of the elastic member 1 is desired to be as small as possible. Therefore, by setting the balance weight portion 301g so that the position of the center of gravity of the positioning mechanism 3 becomes the rotation center of the positioning mechanism 3, when the impact is applied, the positioning mechanism 3 does not rotate and the position can be maintained. Strong structure against external force such as force.

  Therefore, by arranging the balance weight part 301g in the positioning function 3, conventionally, a pressing force for preventing the positioning mechanism from rotating when an impact or the like is applied is at least necessary, but the balance weight part 301g is arranged. As a result, only the necessary pressing force is required on the operating mechanism, so that it is possible to reduce the rotational load on the driven vehicle 4A.

  As described above, the positioning mechanism of the present invention can perform positioning at low load and prevent reverse rotation, which has been considered difficult until now, and does not require position adjustment in accordance with the driven gear position. And low power consumption.

  In the embodiment, the description has been given of the application example to the swinging step motor that drives the two driven gears engaged with each other. However, the application range of the positioning mechanism of the present invention is not limited to this. If it is a timepiece having a gear train mechanism driven by a step motor that has a low holding power for low power consumption, it can be applied to an analog electronic timepiece in which a one-second hand movement is performed by a general step motor. Is possible.

DESCRIPTION OF SYMBOLS 1 Elastic member 2 Elastic member fixing | fixed part 3 Positioning mechanism 301 Positioning mechanism rigid body part 301 'Positioning mechanism rigid body part At the time of reverse rotation prevention function operation | movement 301A The vertex part 301B where a driven gear and a positioning mechanism rigid body part contact | connect Part 301a Positioning mechanism rigid body part 301b Positioning mechanism rigid body part surface 301c Positioning mechanism rigid body part surface 301g Positioning mechanism rigid body part Balance weight part 302 Positioning mechanism rotating shaft 302a Positioning mechanism 3 rotation Center bearing portion 302b Center of rotation of positioning mechanism 3 4A Driven vehicle 401A Rotor drive transmission gear 402A Driven gear 403A Driven shaft 403A 'Driven vehicle Reverse rotation prevention mechanism activated 4B Driven vehicle 401B 501 b Tacham 6 Rotor rotation restricting member 7 Positioning mechanism rigid body portion rotation restricting member 8 Train train receiving member 801 Train train receiving bearing 9 Ground plate 90 Ground plate bearing 10 Positioning mechanism rigid body portion A when the angle α formed is set as 0> α Line segment b drawn from the contact point of the direction line 301A to the center of rotation of the positioning mechanism b Line segment extending vertically from the tangent line of the 301A c Normal rotation direction of the driven gear 4A d Normal rotation direction of the driven gear 4B e Rotation direction f of the positioning mechanism Reverse rotation direction of gear 4A o Positioning mechanism Rotation center

Claims (7)

A positioning mechanism for gears in equipment,
A positioning rigid body (301) pressed against the gear (402A);
At the center of rotation (o) of the positioning rigid part (301),
A positioning rotary shaft (302) fitted to the positioning mechanism rigid body portion (301);
An elastic member (1) that contacts the positioning mechanism rigid body part (301) and applies a biasing force to the gear (402A).
During reverse rotation driving of the gear (402A),
The length of the arm of the moment of force between the contact point between the apex part (301A) of the positioning mechanism rigid body part (301) and the gear (402A) and the rotation center (o) is L1,
During forward rotation of the gear (402A),
The length of the arm of the moment of force between the contact point between the side surface portion (301B) of the positioning mechanism rigid body portion (301) and the gear (402A) and the rotation center is L2,
The positioning mechanism is configured to satisfy L1 <L2. A line segment (a) extending vertically from a tangent line between the vertex (301A) and the gear (402A);
When the angle formed by the line segment (b) drawn from the contact point between the vertex (301A) and the gear (402A) to the rotation center is α,
0 ° <α ≦ Δ
(Δ: Friction angle obtained by the friction coefficient between the gear and the rigid part (301))
The positioning mechanism according to claim 1, wherein: The side portion (301B)
Substantially perpendicular to the vertex (301A),
During forward rotation, it contacts the tooth tip of the gear (402A),
A first surface (301a) entering between the teeth of the gear (402A) during reverse rotation;
Intersects the first surface (301a) at a predetermined angle,
A second surface (301b) that contacts the tooth tip of the gear (402A) during reverse rotation;
The third surface (301c) intersects with the second surface (301b) at a predetermined angle and extends to the vicinity of the rotation center, and is composed of three surfaces having different angles of inclination. The positioning mechanism described. Of the positioning mechanism rigid body portion (301),
In the rotation direction (e) opposite to the urging direction by the elastic member (1),
The positioning mechanism according to any one of claims 1 to 3, further comprising a rotation restricting member (7) for restricting the rotation of the positioning mechanism rigid portion (301). An elastic member fixing portion (2) for fixing the elastic member (1) to the device;
The positioning mechanism according to any one of claims 1 to 4, wherein the elastic member fixing portion (2) has a fall prevention portion (2a) of the positioning rotation shaft (302). The positioning mechanism rigid body (301)
The balance weight part (301g) is provided in the other side of the extending | stretching part (301d) extended to the said vertex part (301A) on both sides of the said rotation center (o), The Claim 1 thru | or 5 characterized by the above-mentioned. The positioning mechanism described in one. The gear (402A)
Of a swinging step motor that drives a train wheel by a rotor (5) that swings at a predetermined angle;
The positioning mechanism according to any one of claims 1 to 6, wherein the positioning mechanism is a driven gear driven by the rotor (5).

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