JP3882759B2 - Polishing method for watch gear - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for polishing a timepiece gear.
[0002]
[Prior art]
The timepiece gear is extremely finely configured to reduce the size and thickness of the movement. Further, the timepiece gear is required to have an extremely smooth tooth surface from the viewpoint of improving the meshing efficiency and preventing rusting in order to increase the timing accuracy or to save energy. For this reason, conventionally, grinding of a timepiece gear is generally performed. As a typical method of polishing, a lapping agent is applied to a polishing material (processing rotating body) having an ultra-large diameter screw or worm-like tooth gap made of wood or special paper. There is known a method of applying polishing to perform polishing (for example, see Non-Patent Document 1 below).
[0003]
[Non-Patent Document 1]
“World Watch 60 World Mook 395, Volume 395, Issued on December 20, 2002” (P.119, text 3) Toothbrushing process, and see FIG. 15)
[0004]
[Problems to be solved by the invention]
However, in the conventional polishing method, the polishing is performed by a method in which the abrasive is rotated and applied to the gear by manually pushing down the lever. For this reason, a high level of craftsmanship is required, and there is a problem that it is difficult to balance maintaining the tooth profile accuracy and reducing the surface roughness of the tooth profile surface unless it is an expert. For example, because the degree of polishing was grasped by relying on the operator's feeling, the improvement in surface roughness was insufficient due to lack of polishing time, or the tooth profile accuracy was significantly deteriorated due to excessive polishing time. There is a problem. Even if the polishing time is accurately set by a timer or the like, it is difficult to maintain a constant polishing pressure during the work, and the polishing pressure varies from worker to worker, resulting in large variations in the finished state of the gears. There is also a problem.
[0005]
Accordingly, the present invention solves the above-mentioned problems, and the problem is that the balance between the tooth profile accuracy and the surface roughness is improved as compared with the prior art by performing automation and control of operations in the gear polishing method and polishing apparatus. It is an object of the present invention to provide a technique capable of improving tooth profile accuracy and surface roughness and improving the reproducibility thereof.
[0006]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, the timepiece gear is held so as to be rotatable about the axis, and the polishing agent is rotated while rotating the wooden processing rotating body with the tooth groove with respect to the outer peripheral portion of the timepiece gear. In the polishing method of the timepiece gear for polishing while rotating the timepiece gear, the processing rotating body and the timepiece are moved at a moving speed such that the timepiece gear is not splashed or damaged. Calibration that detects the stress generated when the gear is brought into contact with a stress sensor, and obtains the relative positional relationship between the timepiece gear and the processing rotor when the stress value reaches a predetermined first stress value. Polishing process with reference to the relative positional relationship, and the stress value is the first stress while contacting the processing rotary body and the timepiece gear at a moving speed optimum for the polishing process. A polishing process for performing polishing until a larger second stress value is obtained, and as a preparatory work for polishing, the outer periphery of the processing rotating body is cut with a dressing tool to remove the runout of the outer periphery. After that, the machining rotating body is contacted with the timepiece gear to perform a copying process in which the tooth groove is formed in the outer peripheral portion.
And in this invention, since the said process rotary body is wooden, handling property is good, and the transcription | transfer property of a tooth gap is good, and its grinding | polishing characteristic is also favorable. For example, when ceramics are used, it is easy to break and transfer of tooth spaces is virtually impossible. In addition, plastic is easily softened or altered by heat generated during copying or polishing. The tooth gap cannot be transferred with metal. As the processing rotating body, beech, cocoon, salmon, chestnut, cherry and the like can be used, but beech is particularly desirable. Further, it is desirable to use a sufficiently dried one. Furthermore, homogeneity can be secured by using a plate material cut out along the axial direction of the timber.
In the preparatory work for polishing, the outer periphery of the processing rotor is cut with a dressing tool to remove runout of the outer periphery, and then the processing rotor is brought into contact with the gear so that the processing rotor Since the copying process for forming the tooth groove on the outer peripheral portion of the gear is performed, the tooth groove corresponding to the tooth profile of the gear to be polished can be reliably formed. Here, by performing the copying process continuously with the calibration process, it is possible to quickly perform the setup before the polishing process.
[0007]
According to the present invention, in the calibration process, the stress is detected and the relative positional relationship between the gear and the processing rotating body when the value of the stress reaches the first stress value is obtained. By carrying out the polishing process under the polishing conditions based on the relative positional relationship of the relative position of the gear, the relative positional relationship between the gear and the processing rotating body can be grasped quantitatively and objectively. By performing polishing under the polishing conditions based on the positional relationship, stable polishing with little variation can be realized. In addition, by performing the polishing process based on the above relative positional relationship, it is possible to secure a balance between the tooth profile accuracy and the surface roughness of the gear. In particular, when the processing rotator with tooth gaps is made of wood or paper, since the wear of the processing rotator during polishing is severe, the outer periphery of the processing rotator is always maintained by grasping the relative positional relationship. It is possible to perform polishing while maintaining a constant wear state.
[0008]
Here, the polishing condition based on the relative positional relationship means that there is a condition depending on a predetermined position based on the relative positional relationship among the polishing conditions. After performing a polishing process at a predetermined position, performing a polishing process while moving within a predetermined range from a predetermined position based on a relative positional relationship, or after reaching a predetermined position based on a relative positional relationship For example, the polishing process may be terminated after a predetermined time has elapsed. In addition, as a method of bringing the gear and the machining rotator close to each other, the gear is fixed and only the machining rotator approaches the gear, the machining rotator is fixed, and the gear moves close to the machining rotator. Any method may be used, or a method in which both the gear and the processing rotating body move and approach each other.
[0009]
In the present invention, in the process of bringing the gear and the processing rotating body closer to each other before the start of polishing in the polishing step, the gear and the gear are reached when a positional relationship that is a predetermined distance away from the relative positional relationship is reached. It is preferable to reduce the approach speed of the processing rotating body. Normally, in the polishing process, polishing is started by bringing the gear and the processing rotating body close to each other and bringing them into contact with each other. However, in the process of bringing the gear and the processing rotating body close to each other before polishing, When approaching at a high speed to shorten the cycle time of the machining process, the gear may jump off or damage the gear, and when approaching at a low speed, it becomes difficult to shorten the cycle time. . Therefore, initially shortening the cycle time and preventing gear spatter and damage by making the gear and the processing rotating body suddenly approach at high speed, decelerate from the middle, and approach slowly at low speed. Both can be achieved. Since the optimum value of the timing for changing the speed depends on the relative positional relationship, the timing at which the positional relationship separated by a predetermined distance from the relative positional relationship is reached is set as the timing based on the relative positional relationship. By doing so, a reliable effect can be always obtained. Here, the speed before and after the timing does not need to be constant in the approaching process, and the speed may be gradually decreased in a predetermined deceleration mode. In this case, there is no limitation on the position corresponding to the above time point, and it may correspond to the deceleration start position, may correspond to the deceleration end position, or corresponds to the intermediate position in the deceleration process. It may be.
[0010]
In the present invention, in the polishing step, a predetermined time has elapsed from the time when the stress value has reached a second stress value larger than the first stress value in the process of bringing the gear and the processing rotor close together. It is preferable to finish the polishing process later. As a result, the polishing can be performed for a certain period of time with the polishing pressure set to a substantially constant value, so that the reproducibility of the polishing state can be improved.
[0011]
In the present invention, it is desirable to perform the polishing process by stopping the approaching operation between the gear and the processing rotating body when the stress value reaches a second stress value larger than the first stress value. According to this, since the positional relationship between the gear and the processing rotating body is fixed in a state in which the polishing pressure reaches a predetermined stress value, it is difficult for the polishing pressure to change, and polishing processing with higher reproducibility can be performed. Is possible.
[0012]
In the polishing process according to the present invention, the polishing process is performed while bringing the gear and the processing rotating body close to each other, and the polishing process is performed when the stress value reaches a second stress value larger than the first stress value. Is preferably terminated. According to this method, since the polishing pressure at the end of the polishing process becomes substantially constant, the reproducibility of the polishing state can be improved.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of a gear polishing method and polishing apparatus, gears, equipment, and timepiece according to the present invention will be described in detail with reference to the accompanying drawings.
[0025]
FIG. 1 is a schematic configuration diagram illustrating a configuration of a main part of a gear polishing apparatus according to the present embodiment, and FIG. 2 is a schematic configuration diagram illustrating an overall configuration of the polishing apparatus. As shown in FIG. 2, the polishing apparatus 100 of this embodiment includes a polishing mechanism 100A and a control unit 100B that controls the polishing mechanism 100A.
[0026]
As shown in FIG. 1, the polishing mechanism 100 </ b> A is provided with a processing unit 110 including a processing rotating body 111 and a holding unit 120 for holding a gear G to be processed. The processing unit 110 includes a drive source 112 configured by an electric motor or the like for rotationally driving the processing rotator 111. Moreover, the moving mechanism 113 for moving the process rotary body 111 and the drive source 112 up and down in the figure is provided. As the moving mechanism 113, for example, as shown in the figure, a drive source 113a constituted by an electric motor (stepping motor), a feed screw mechanism (or a ball screw mechanism) including a nut 113b and a screw shaft 113c, A configuration having a guide mechanism including a guide body 113d and a guide shaft 113e can be employed.
[0027]
The holding unit 120 has a positioning table (XYθ table) 121 installed on the base 101. On the positioning table 121, a stress sensor (load cell) 122 is installed. The stress sensor 122 is provided with a detector 122a that receives stress. A support base 123 is fixed to the detection unit 122a, and a pair of positioning bases (XY tables) 124L and 124R are installed on the support base 123. An L-shaped support tool 127L is fixed on the positioning table 124L. A positioning tool (elevating shaft guide) 126 is mounted on the positioning table 124R via a mounting tool 125, and a support tool 127R is fixed to the positioning tool 126.
[0028]
Holding members 128L and 128R are attached to the supports 127L and 127R, respectively, and these holding members 128L and 128R are arranged to face each other with a predetermined interval. The holding members 128L and 128R are attached to the supports 127L and 127R so as to be rotatable and movable in the axial direction. Each of the holding members 128L and 128R has a substantially disk shape. Further, as shown in FIG. 7, a concave groove 128a is formed in the outer peripheral portion of the holding member. By forming the concave groove 128a as a V-groove as shown in the figure, the shaft portion of the gear G, which will be described later, or the outer peripheral surface of the shaft passing through the gear G is formed on a cylindrical surface, the shaft portion or the shaft is supported. The rotational resistance of the gear G can be reduced by making the contact portion a line contact.
[0029]
A plurality of concave grooves 128a are formed in a distributed manner on the outer peripheral portions of the holding members 128L and 128R. The plurality of concave grooves 128a include different sized concave grooves having different depths or widths. In addition, a plurality of positioning holes 128b, 128c, and 128d (which may be through holes or stop holes) are formed around the axis on the inner plate surface of the outer peripheral portion. The positioning holes 128b, 128c, and 128d are formed at mutually different radial positions, and the angular positions around the respective axes correspond to any one angular position of the concave groove 128a. Then, concave grooves (that is, three concave grooves in the illustrated example) 128a having the same dimensions are formed corresponding to the angular positions of the pair of positioning holes 128b, 128c, and 128d. The positioning holes 128b, 128c, and 128d adjacent to the axis line S are formed at positions shifted from each other around the axis line S so that they do not interfere with each other even if the diameter of the positioning hole is increased. Note that the positioning accuracy in the rotational direction with respect to the holding member can be increased by increasing the diameter of the positioning hole.
[0030]
Referring back to FIG. 1 again, the support tools 127L and 127R are provided with through holes (not shown) at radial positions corresponding to the positioning holes 128b, 128c and 128d, respectively. The positioning pins 129L and 129R are inserted into one of them, and the tips thereof are fitted in any one of the positioning holes 128b, 128c and 128d. With such a configuration, the positioning pins 129L and 129R are configured so that the angular positions of the left and right holding members 128L and 128R around the axis can be fixed to the support tools 127L and 127R.
[0031]
In the polishing mechanism 100A, a support base 103 is fixed on a support column 102 erected on the base 101, and a dressing tool is provided on the support base 103 via a feed guide 131, a fixing base 132, a positioning base 133, and the like. 134 is fixed. The dressing tool 134 is a cutting tool such as a cutting tool configured to be capable of cutting the outer peripheral portion of the processing rotating body 111 with a cutting blade 134a formed at the tip. By positioning the dressing tool 134 at a predetermined position and bringing the dressing tool 134 into contact with the outer periphery of the processing rotator 111 in a state where the processing rotator 111 is rotationally driven, the outer periphery can be cut.
[0032]
As shown in FIG. 2, on the outer surface of the control unit 100B, a power-on operation unit (switch) 104A, a power-off operation unit (switch) 104B, a stress display unit (load cell display unit) 105, a panel operation unit (touch panel). 106, a sound report section (speaker for buzzer) 107, and a safety device (earth leakage breaker) 108 are arranged. As shown in FIG. 4, the control unit 100B includes a control device 100P that performs control and calculation of the entire device, and an input unit 100I (a power-on operation unit 104A and a power-off operation unit 104B) connected to the control device 100P. Panel operation unit 106) and display unit 100D (stress display unit 105, sound report unit 107). As the control device 100P, an MPU (microprocessor unit), a programmable controller, or the like can be used. In addition, a plurality of position sensors 100S installed in the polishing mechanism 100B are connected to the control device 100P. These position sensors 100S include limit sensors (for example, upper and lower limit sensors of the moving mechanism 113), shift position sensors (for example, sensors that determine the shift position of the moving mechanism 113), sensors for safety devices, and the like. Can be mentioned. Further, the output of the stress sensor 122 is connected to the control device 100P. The output of the stress sensor 122 is displayed on the stress display unit 105 in addition to being used as control data by the control device 100P. In some cases, the stress display unit 105 is used to obtain a predetermined output by being compared with comparison data (stress threshold or other reference value) set appropriately.
[0033]
The control unit 100B is provided with a storage device 100T including various storages such as a memory, a hard disk, and a magnetic tape, and is connected to the control device 100P. The control device 100P writes various data to the storage device 100T or reads various data recorded in the storage device 100T in accordance with the operation content in the input unit 100I and a preinstalled program.
[0034]
The control device 100P is connected to the drive source 112, and is configured to control and drive the drive source 112 so that the processing rotating body 111 can be rotated at an appropriate rotation speed and can be stopped at an appropriate timing. Moreover, you may be comprised so that the rotation direction of the process rotary body 111 can be controlled. Further, the control device 100P is also connected to the drive source 113a, and can control and drive the drive source 113a to move the processing rotating body 111 up and down at an appropriate moving speed by the moving mechanism 113. It is comprised so that it can be stopped at a position.
[0035]
In the polishing apparatus 100 described above, it is preferable that the processing rotating body 111 is made of wood. The wood is preferably beech, straw, cocoon, chestnut, cherry or the like, but beech is particularly desirable. Further, when the processing rotating body 111 is made of wood, it is preferable to use a plate material cut out along the axial direction of the wood in order to increase the uniformity of hardness and reduce the influence of warpage or the like. This is to avoid variations in hardness due to annual rings and hardness variations due to the density of annual rings between the south and north sides when using a plate cut out in a direction perpendicular to the axis of the wood. This is because the variation width of the characteristics depending on the location can be reduced. As a result, the wear in the polishing process on the outer periphery of the processing rotating body can be made uniform, and the grooves due to the profiling are also uniformly generated.
[0036]
The processing rotating body 111 is configured in a substantially disc shape as a whole. In particular, as shown in FIG. 3, the outer periphery of the plate surface is tapered so as to become thinner toward the outer edge. The outer peripheral portion 111a of the processing rotating body 111 is basically a cylindrical surface with a small width. Such a shape of the outer peripheral portion 111a is formed by the dressing tool 134 shown in FIG.
[0037]
As shown in FIG. 1, the gear G is in a state in which the shaft (hozo) or the shaft inserted through the gear G is fitted and supported to the concave groove 128a (see FIG. 7) of the holding members 128L and 128R. Be placed. The positional relationship between the gear G and the holding members 128L and 128R is appropriately changed according to the shape of the gear G. For example, when the diameter of the shaft portion of the gear G or the shaft passing through the gear G is different on the left and right, the left and right holding members 128L and 128R can select the concave grooves 128a having different dimensions, or the positioning portion 126 can be moved in the vertical direction. To change the height of the support tools 127L and 127R. Only one of the dimension of the concave groove 128a and the left and right heights of the support portion may be changed, or both may be changed together.
[0038]
FIG. 10 shows variations of the holding state of the gears G1 to G3 and the holding members 128L and 128R. A gear G1 shown in FIG. 10 (a) is a fifth watch of a portable timepiece, and changes the depth of the concave grooves 128a of the left and right holding members 128L and 128R, or changes the left and right heights of the support tools 127L and 127R. This shows a state where the axis of the gear G1 is held so as to be horizontal. Here, the gear G1 (fifth pinion) has a tenon that protrudes to the left and right. However, since the tip portion of the smallest diameter of this hozo is a portion that is pivotally supported, the tip portion is not damaged so as not to be damaged. Instead, it is in a state in which a larger diameter base portion close to the gear portion is supported by the concave groove 128a.
[0039]
The gear G2 shown in FIG. 10 (b) is a third watch of the portable timepiece, and the left and right support heights are changed as described above. In the case of the gear G2, since the gear portion is long in the axial direction, the interval between the left and right holding members 128L and 128R is increased. The distance between the holding members 128L and 128R can be easily adjusted by changing the mounting positions of the holding members 128L and 128R with respect to the supports 127L and 127R.
[0040]
A gear G3 shown in FIG. 10 (c) is the second pinion of the portable timepiece, and has a shaft hole formed at the center thereof. In this case, the shaft ST is inserted into the shaft hole of the gear G3, and the shaft ST is held by the left and right holding members 128L and 128R. Thus, the gear G3 can be held in a freely rotatable state without any trouble.
[0041]
3A is a front view showing the processing rotator 111 and the gear G, and FIG. 3B is a plan view showing the relationship between the processing rotator 111 and the gear G. FIG. The machining rotator 111 has a plate surface slightly inclined at an inclination angle θ with respect to the axis of the gear portion of the gear G. This inclination angle θ is defined such that the outer diameter (diameter) of the processing rotator 111 is D, the standard pitch of the teeth of the gear G is P, and the number of teeth of the gear G sent by one rotation of the processing rotator 111 is Z.
πDsinθ = ZP (1)
Because there is a relationship
θ = sin ^-1 (ZP / πD) (2)
May be used to set the inclination angle θ. The inclination angle θ is normally set by adjusting the θ axis of the positioning table 121 (see FIG. 1). As the inclination angle θ is increased, the number of teeth Z sent by one rotation of the processing rotating body 111 is increased, but the tooth profile accuracy is lowered. Therefore, it is usually preferable to set the inclination angle θ within a range of 0.5 to 3 [deg]. In particular, it is more desirable to set it within the range of 1.0 to 2.0 [deg].
[0042]
FIG. 3C shows a cross-sectional shape in the vicinity of the outer peripheral portion 111 a of the processing rotating body 111. When the outer peripheral portion 111a is brought into contact with the gear G at the inclination angle θ satisfying the above expression (2) while the processing rotary body 111 is rotationally driven, the outer peripheral portion 111a of the processing rotary body 111 rotates the gear G. However, it is scraped by the teeth of the gear G to form a tooth groove 111b. The tooth groove 111b is formed to extend in a direction inclined by an inclination angle θ with respect to the rotation direction of the processing rotating body 111. By performing such copying, the outer peripheral portion 111a of the processing rotating body 111 has a shape suitable for polishing the gear G. That is, the tooth gap 111b is a screw or worm-shaped one. Thus, the processing rotating body 111 once copied by the gear G can be used as it is for the gear G having the same shape. However, in order to increase the tooth profile accuracy and the polishing effect, even if the gear has the same shape, the above-described copying process may be performed for each gear G to be processed, and then the polishing process may be performed.
[0043]
It is preferable that the tooth groove 111b is always formed on the outer peripheral portion 111a of the processing rotating body 111 by about 2 to 3 threads. This is because if only one strip is used, the grinding efficiency of the gear G is lowered and the rotational drive capability of the gear G is also poor, and if it is four strips or more, the tooth profile of the gear G may be deteriorated.
[0044]
As shown in FIG. 1, an imaging means (for example, a CCD camera) 141 having a field of view set at the holding position of the gear G is provided. The imaging means 141 preferably images the holding posture of the gear G via the magnifying optical system 142 such as a telecentric optical system. The photographed image is displayed on the panel operation unit 106 or the like. Therefore, the operator can confirm the posture of the gear G held by the holding unit 120 with the enlarged image. In this way, when the gear G is small (for example, in the apparatus of the present embodiment, a small gear having a diameter of 0.5 mm to several mm and a length of about 1 mm to several tens of mm is targeted), the gear G is held. This is because it is difficult to determine the quality of the posture with the naked eye.
[0045]
Next, the operation of the polishing apparatus 100 described above and a method of polishing using the same will be described with reference to FIGS. In this polishing apparatus 100, first, the following operations (preparation processing of a processing rotating body, adjustment / setting of a holding portion, molding of a processing rotating body) are performed as a preparation step for polishing processing. First, the processing rotator 111 is cut by the dressing tool 134 while rotating the processing rotator 111 as described above. In this operation, the processing rotor 111 is not shaken and shaped. Next, the gear G is set on the holding members 128L and 128R. At this time, the height of the holding member and the angular position in the rotation direction are set so that the axis of the gear G is horizontal, and the positioning table 121 and the positioning tool 126 are adjusted. The tilt angle θ is also adjusted / set by the positioning table 121. Thereafter, the machining rotator 111 is brought into contact with the gear G, and the copying is performed so that the tooth profile of the gear G is transferred to the outer peripheral portion 111a. As a result, the tooth groove 111b of the processing rotating body 111 is formed as described above.
[0046]
Next, the operation and method of the polishing apparatus 100 when polishing the processing rotating body 111 will be sequentially described. As described above, when the machining rotator 111 has already undergone copying, the power-on operation unit 104A of the polishing apparatus 100 is operated (pressed) to turn on the power, and the panel operation unit 106 shown in FIG. When the origin return button is pressed, the movement position setting shown in FIG. 5A is automatically performed. In this movement position setting, the processing rotating body 111 is first moved to the origin position by the movement mechanism 113, the position coordinates when the origin signal of the origin position sensor (not shown) is read are memorized, and then moved to the standby position. Stop.
[0047]
When the setting of the movement position of the movement mechanism 113 is completed as described above, the calibration operation shown in FIG. In this calibration step, first, when the processing rotator 111 is at a position other than the standby position, it is moved to the standby position. Then, a high-speed downward movement is performed from this standby position. Then, when a sensor (the above-described shift position sensor) set in the middle position of the movement path detects a moving portion of the movement mechanism 113, the speed of the downward movement is reduced and the movement proceeds to the low-speed downward movement. When the output of the stress sensor 122 changes while slowly descending in this way, the threshold value is further lowered from the position (hereinafter simply referred to as “contact position”) and is higher by a preset offset amount. When (first stress value) is detected, the position (hereinafter simply referred to as “first stress value detection position”) is stored. Then, it rises to the standby position.
[0048]
The polishing start position obtained by the calibration operation is used as a reference position for polishing. Then, with this polishing start position as a reference, a position (hereinafter simply referred to as “proximity position”) where the processing rotating body 111 has returned by a predetermined distance and does not contact the gear G is set. It is also possible to set a position (hereinafter simply referred to as “second stress value detection position”) where the second stress value is detected by lowering by a predetermined distance with respect to the polishing start position. Various parameter setting operations are performed by the panel operation unit 106.
[0049]
The polishing apparatus 100 is configured such that the moving speed of the moving mechanism 113 can be set in accordance with the position of the moving mechanism 113 (the vertical position in the illustrated example). (1) Movement speed V1: Standby position to proximity position
(2) Movement speed V2: proximity position to first stress value detection position
(3) Movement speed V3: first stress value detection position to second stress value detection position
(4) Movement speed V4: second stress value detection position to standby position
[0050]
Here, the moving speed V1 is high and is set for the purpose of reaching the polishing region in a short time. Further, the moving speed V2 is lower than V1, and it is intended to prevent the gear G from jumping off or being damaged when the processing rotating body 111 contacts the gear G at a high speed. Is set. The moving speed V2 may be configured to be determined by feedback control in which the output of the stress sensor is maintained at a value lower than the first stress value. Further, the moving speed V3 is configured so that an optimum moving speed for polishing can be set and input as appropriate. Note that the moving speed V3 may be subject to speed control so that a constant polishing pressure can be obtained. The moving speed V4 is a speed when returning from the end of polishing to the standby position, and is normally set at a high speed.
[0051]
The calibration process is preferably performed before the following polishing process every time a new gear G is set, but every time a predetermined number (any natural number) of gears G is polished. You may go. This is because when the gear G is polished, the outer peripheral portion 111a of the processing rotator 111 is scraped, so the outer diameter D of the processing rotator 111 changes, and the polishing start position also changes accordingly. is there.
[0052]
FIG. 6 shows a procedure of a polishing operation (automatic operation) that is automatically performed. In this polishing process, a polishing material containing abrasive grains such as alumina is applied to the outer peripheral portion 111a of the processing rotating body 111 in advance. Abrasive grains contained in the abrasive can be appropriately set depending on the polishing accuracy, but for a small gear for a watch, the average particle diameter is preferably about 1 μm (about mesh 8000). Moreover, it is preferable to prepare a slurry liquid in which abrasive grains are dispersed in a liquid medium such as oil and to use it as the abrasive.
[0053]
In this polishing process, first, various parameters used in the polishing process are set in the input unit 100I. The various parameters include the rotation direction and rotation speed of the processing rotating body 111, the moving speeds V1 to V4, the stress value during polishing, and the polishing time. Next, the driving source 113a is operated to rotate the processing rotating body 111. Then, when the gear G is set in the holding unit 120, a high-speed descending movement is started by pressing the start button. Then, the movement proceeds to a low-speed downward movement at the above-mentioned proximity position, reads a stress value (hereinafter also referred to as “polishing pressure”) detected by the stress sensor, and stops the lowering of the processing rotating body 111 when the specified polishing pressure is reached. Let Then, when the polishing time timer is activated and the specified polishing time has elapsed, the polishing is completed, the medium speed ascending movement is performed to move the processing rotating body 111 away from the gear G, and then the high speed ascending movement is performed after passing the proximity position. Transition. Thereafter, when the gear G is removed from the holding unit 120, the polishing process is completed. In the above step, the polishing time is preferably in the range of 0.5 to 3.5 seconds. In particular, it is desirable to be about 1.5 to 2.5 seconds. In addition, it is preferable that the rotation speed of the process rotary body 111 at the time of grinding | polishing is about 300-1000 rpm.
[0054]
In the polishing process shown in FIG. 6, when the specified polishing pressure (second stress value) is detected, the processing rotary body 111 stops moving downward, and polishing is performed. The specified polishing time is set in advance. Polishing is terminated when (for example, 2 seconds) elapses. However, instead of such a method, the polishing is continued while forcibly moving to the above-described predetermined polishing end position at the predetermined moving speed V3, and the polishing is ended when the polishing end position is reached. Also good. Further, the movement from the polishing start position to the polishing end position may be moved at a movement speed V3 controlled so as to be a preset specified polishing pressure.
[0055]
The gear G polished as described above is cleaned with an appropriate cleaning liquid, and the abrasive grains adhering to the surface are sufficiently removed. FIG. 8 shows the specified polishing pressure when the polishing process is performed by the method shown in FIG. 6, the surface roughness Ra [μm] of the tooth surface of the gear G after polishing, and the tooth surface remaining (embedded). ) Shows the relationship with the number of abrasive grains (media). As can be seen, when the specified polishing pressure is in the range of 25 to 60 [kPa] (0.25 to 0.60 [kg · f]), the surface roughness Ra is minimized and the number of remaining media is small. It became the minimum. Furthermore, a very high effect is acquired when it is in the range of 27 to 40 [kPa]. In particular, as for the surface roughness Ra, the tooth surface roughness of the gear G after gear cutting (before polishing) is about Ra = 0.20 [μm], but Ra = 0.01 [μm]. It dropped dramatically until. An enlarged photograph of the teeth of the gear G before and after polishing is shown in FIG. As shown in these figures, a very smooth tooth surface is obtained. In addition, there was no problem with the tooth profile accuracy, and the reproducibility of the tooth profile accuracy was sufficiently high.
[0056]
[Clocks and clocks for watches]
FIG. 11 is a schematic configuration diagram schematically showing the internal structure of the portable timepiece 1 as a device or watch according to the present invention, and FIGS. 12 and 13 are partial sectional views showing the internal structure of the portable timepiece 1. As shown in FIG. 11, the portable timepiece 1 includes a power generation unit 20 and a timepiece driving unit 30. The power generation unit 20 includes a small generator having a power generation rotor 21, a power generation stator 22, a coil 23, and a magnetic core 24. As shown in FIG. 13, a rotor kana 21 a is attached to the power generating rotor 21. The rotor kana 21 a meshes with the transmission wheel 25, and the transmission wheel 25 meshes with the spindle wheel 26. The spindle 26 is fixed to the rotary spindle 27. The coil 23 is connected to a secondary battery, a large-capacity capacitor, or the like via a storage circuit (not shown).
[0057]
Further, the timepiece drive unit 30 is provided with a stepping motor having a rotor 31, a stator 32, a coil 33 and a magnetic core 34. Here, as shown in FIG. 12, a rotor kana 31 a is attached to the rotor 31. The rotor kana 31 a meshes with the third wheel 35, and the third wheel 35 meshes with the second wheel 36. The center wheel & pinion 36 is configured to rotationally drive an hour wheel 38 via a minute wheel 37. The minute hand 41 is attached to the center wheel & pinion 36, and the hour hand 42 is attached to the hour wheel 38. The coil 33 of the stepping motor is connected to a timepiece driving circuit (not shown). The timepiece driving circuit is supplied with power from the secondary battery or the large capacity capacitor.
[0058]
In FIGS. 12 and 13, reference numeral 2 denotes a ground plane, and 3 denotes a train wheel bridge. These gears are rotatably supported by these gears. Reference numeral 4 denotes a dial.
[0059]
When the rotor 30a attached to the rotor 31 of the stepping motor in the driving unit 30 of the portable timepiece 1 is polished by the above-described method, and the train wheel is configured using the rotor cana 31a, the conventional product (Ra = 0.2 μm) is obtained. The transmission efficiency of the rotational driving force in the driving wheel train was improved by 30%. Thereby, the hands of the minute hand 41 and the hour hand 42 can be enlarged, and the visibility is improved. Further, when the rotor kana 21a attached to the rotor 21 of the power generation unit 20 of the portable timepiece 1 was also polished by the above method, the power generation efficiency was improved by 30%, and the gear sound was heard smoothly.
[0060]
In addition, by using the gear of this embodiment in various devices, generation of static electricity in the meshing portion of the gear is suppressed, reduction of gear wear, prevention of gear surface oxidation and corrosion, and accompanying aesthetic enhancement, electrostatic sparking. It is possible to suppress the defect of the IC (timepiece circuit or the like) and other circuit portions that are caused. These effects particularly contribute greatly to improving the yield of various devices (electronic devices), reducing failure, and improving durability.
[0061]
It should be noted that the gear polishing method and polishing apparatus, gears, equipment, and timepiece of the present invention are not limited to the above illustrated examples, and various modifications can be made without departing from the scope of the present invention. Of course.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing a configuration of a polishing mechanism of a polishing apparatus according to the present invention.
FIG. 2 is a schematic configuration diagram showing an overall configuration of a polishing apparatus.
FIG. 3 is a front view (a), a plan view (b), and an enlarged cross-sectional view (c) of an outer peripheral portion of the processing rotating body, showing a positional relationship between the gear and the processing rotating body.
FIG. 4 is a schematic block diagram showing a configuration of a control unit of the polishing apparatus.
FIG. 5 is a schematic flowchart (a) showing a procedure for setting a movement position and a schematic flowchart (b) showing a procedure for calibration.
FIG. 6 is a schematic flowchart showing a procedure of a polishing process (automatic operation).
FIG. 7 is an enlarged side view showing the shape of the holding member.
FIG. 8 is a graph showing the relationship between the polishing pressure, the surface roughness of the gear, and the remaining number of media.
FIGS. 9A and 9B are photographs (a) and (b) showing tooth surfaces of a gear before and after polishing.
FIG. 10 is an explanatory diagram (a) to (c) showing a holding state of the gears G1 to G3 by a holding member.
FIG. 11 is a schematic configuration perspective view of a main part of the portable timepiece.
FIG. 12 is a partial cross-sectional view of a portable timepiece.
FIG. 13 is a partial cross-sectional view showing different parts of the portable timepiece.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Polishing apparatus, 100A ... Polishing mechanism, 100B ... Control part, 110 ... Processing part, 111 ... Processing rotary body, 112 ... Driving source, 113 ... Moving mechanism, 113a ... Driving source, 121 ... Positioning stand, 122 ... Stress sensor , 128L, 128R ... holding member, 134 ... dressing tool, 100P ... control device, 100I ... input unit, 100S ... position sensor, 100T ... storage device, 1 ... portable watch, 21a, 31a ... rotor kana

Claims (4)

A timepiece gear is held rotatably about an axis, and a wooden processing rotating body with a tooth groove is brought into contact with an outer peripheral portion of the timepiece gear through an abrasive while rotating, and the timepiece gear is In the grinding method of the clock gear for grinding while rotating,
The stress generated when the processing rotating body and the timepiece gear are brought into contact with each other at a moving speed at which the timepiece gear is not jumped off or damaged is detected by a stress sensor, and the value of the stress is determined in advance. A calibration step for obtaining a relative positional relationship between the timepiece gear and the processing rotating body when the stress value is reached;
A polishing process is started on the basis of the relative positional relationship, and a second stress whose stress value is larger than the first stress value while the processing rotating body and the timepiece gear are in contact with each other at a moving speed optimum for the polishing process. And a polishing process for performing polishing until the value is reached,
As a preparatory work for polishing, the outer periphery of the processing rotating body is cut with a dressing tool to remove runout of the outer peripheral portion, and then the processing rotating body is brought into contact with the timepiece gear to form the outer peripheral portion. A method for polishing a timepiece gear, wherein a copying process for forming the tooth gap is performed.   In the process of bringing the timepiece gear and the processing rotary body into contact with each other before the start of polishing in the polishing step, the timepiece gear and the timepiece gear when reaching a positional relationship separated by a predetermined distance from the relative positional relationship. The method for polishing a timepiece gear according to claim 1, wherein a contact speed of the processing rotating body is reduced.   In the polishing process, the polishing is performed after a lapse of a certain time from the time when the stress value reaches the second stress value larger than the first stress value in the process of contacting the timepiece gear and the processing rotating body. The method for polishing a timepiece gear according to claim 1 or 2, wherein the processing is terminated.   In the polishing process, polishing is performed while contacting the timepiece gear and the processing rotating body, and the polishing process is terminated when the stress value reaches a second stress value larger than the first stress value. The method for polishing a timepiece gear according to claim 1 or 2, wherein:

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