JP3820864B2 - Equal interval positioning mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an equidistant positioning mechanism that always keeps attachment positions of parts with respect to a work at equidistant intervals.
[0002]
[Prior art]
FIG. 4 is a schematic view showing a rear door hinge of a general truck box. As shown in the figure, this door hinge is configured by attaching parts (such as brackets) 104 to the long workpieces 101, 102, 103 at equal intervals.
Here, the bracket 104 is fixed to the workpieces 101 to 103 by welding. When performing such attachment work, the bracket 104 and the workpieces 101 to 103 are fixed with a jig (not shown), and welding is performed in this state.
[0003]
[Problems to be solved by the invention]
By the way, since such door hinges differ in length depending on the model or the like, the length of the workpiece also varies accordingly. When performing work such as attaching the bracket 104 to the workpieces 101 to 103 having different lengths at equal intervals in this way, it is necessary to check the position of the jig on the scale each time and perform positioning. There is a problem that it is not efficient.
[0004]
As a method for positioning the jig, for example, the following method can be considered in addition to the above-described manual positioning method by one place.
(1) Positioning one place at a time by one servo motor (2) Simultaneous positioning at a plurality of places by a plurality of servo motors The above (1) and (2) are the positions of jigs by driving the servo motor. However, the problem {circle around (1)} is that the positioning can be performed with high accuracy and the cycle time is long although the apparatus is relatively inexpensive. Although (2) can perform positioning with high accuracy and can shorten the cycle time, there is a problem that the apparatus is expensive.
[0005]
In Japanese Utility Model Publication No. 7-37790, although a component arrangement pitch changing device is disclosed in which the component arrangement pitch is set to a required assembly pitch, the device disclosed in the above publication is large. There exists a subject that it becomes a complicated structure and therefore manufacturing cost is also high.
The present invention has been devised in view of such problems, and provides an equidistant positioning mechanism that can always easily perform equidistant positioning on workpieces having different lengths and sizes with a simple configuration. The purpose is to do.
[0006]
[Means for Solving the Problems]
Therefore, in the equidistant positioning mechanism according to the first aspect of the present invention, when the rotating shaft rotates, the driving gear rotates integrally with the rotating shaft, and this rotational driving force is transmitted to the driven gear meshing with the driving gear. . Then, when the driven gear rotates, the driven gear rotates around the screw shaft, and the driven gear advances and retreats. Here, a plurality of gear mechanisms comprising the drive gear and the driven gear meshing with each other are arranged in the axial direction, and among these gear mechanisms, the gear mechanism provided at the end is the first. In this case, the value of the gear ratio between the driving gear and the driven gear of the nth gear mechanism is set to a value n times the gear ratio between the driving gear and the driven gear of the first gear mechanism. . That is, based on the gear ratio of the first gear mechanism, the gear ratio of the second gear mechanism is doubled, the gear ratio of the third gear mechanism is tripled, and so on. Is set. Thereby, at the time of rotation of a rotating shaft, each gear mechanism moves to an axial direction, always maintaining the state of equal intervals.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a description will be given of an equally-spaced positioning mechanism according to an embodiment of the present invention with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the configuration of the main part, and FIGS. FIG. 3 is a diagram for explaining the operating principle.
As shown in FIG. 1, a plurality of bases (stations) ST1, ST2, ST3,... Are slidably disposed on the linear guide 1 at equal intervals. Here, if an arbitrary point on the left side in FIG. 1 is an origin (base point) O, the distance from the origin O to the first base ST1 and the distances (pitch) between adjacent bases are all equal. Is set to
[0008]
Further, each base ST1, ST2, ST3,... Is provided with a housing (holding member) 2, and an outer surface 2a of the housing 2 [see FIGS. A jig (not shown) for fixing the component is attached.
In addition, since the structure in the housing 2 of each base ST1, ST2, ST3, ... is comprised similarly except the gear ratio of the gear mentioned later, below, it demonstrates paying attention to one base. To do.
[0009]
Two gears (drive gear and driven gear) 3 and 4 are rotatably supported in the housing 2 via bearings 10 and 11. Moreover, these gears 3 and 4 are attached to the housing 2 so that a relative shift | offset | difference does not arise in an axial direction.
These gears 3 and 4 mesh with each other, and a gear mechanism is configured by the two gears 3 and 4 meshing with each other in this way.
[0010]
The drive gear 3 is configured to rotate integrally with a spline shaft (rotary shaft) 5 provided in parallel to the linear guide 1 described above. The ball screw (screw shaft) 6 arranged in parallel is configured to be rotatable around an axis.
Here, paying attention to the drive gear 3, the drive gear 4 includes a spline outer cylinder 3a, a main body 3b, a tooth portion 3c, and the like. Among these, the spline outer cylinder 3a meshes with the spline shaft 5, and the main body 3b is fixed to the spline outer cylinder 3a. And the tooth | gear part 3c and the main body 3b are being fixed with the volt | bolt 3d etc. so that the rotation center axis | shaft of the tooth | gear part 3c and the spline shaft 5 may correspond.
[0011]
Next, the driven gear 4 will be described. The driven gear 4 includes a nut 4a, a main body 4b, a tooth portion 4c, and the like, and the nut 4a is screwed into the ball screw 6. Unlike the spline shaft 5, the ball screw 6 is fixed so as not to rotate.
And while the nut 4a and the main body 4b are fixed, the tooth | gear part 4c is attached to the main body 4b so that the center axis | shaft of the tooth | gear part 4c and the ball screw 6 may correspond.
[0012]
Therefore, when the spline shaft 5 rotates, the drive gear 3 rotates, and this rotational driving force is transmitted to the driven gear 4 that meshes with the drive gear 3. When the rotational driving force is transmitted from the drive gear 3 to the driven gear 4, the driven gear 4 moves along the axial direction of the ball screw 6 while rotating around the ball screw 6. Further, as described above, the drive gear 3 and the driven gear 4 are attached to the housing 2 so as not to cause a relative shift in the axial direction. Therefore, when the spline shaft 5 is rotated, the drive gear 3 is also connected to the spline shaft 5. Rotates while sliding in the axial direction. Thereby, when the spline shaft 5 rotates, the housing 2 moves as a whole.
[0013]
Although not shown, a steel ball is provided between the nut 4a and the ball screw 6, so that the advance / retreat position can be adjusted with high accuracy when the driven gear 4 rotates.
In each of the bases ST1, ST2, ST3,..., The gear ratio m between the drive gear 3 and the driven gear 4 [here, the gear ratio m = (the number of teeth Z1 of the drive gear 3) / (the driven gear 4 of the driven gear 4). Defined as number of teeth Z2)] is set differently.
[0014]
Here, if the gear ratios of the bases ST1, ST2, ST3, ST4,... Are m1, m2, m3, m4,..., M1: m2: m3: m4:. : 2: 3: 4:... That is, among each base, the gear ratio value of the second base ST2 is set to be twice the gear ratio of the first base ST1 closest to the origin, and the third base The gear ratio value of ST3 is set to 3 times. Hereinafter, similarly, the value of the gear ratio of the n-th base STn is set to be n times the gear ratio of the first base ST1.
[0015]
Specifically, in the present embodiment, as shown in FIGS. 2A to 2D, the gear ratio m1 of the base ST1 is 0.5, the gear ratio m2 of the base ST2 is 1.0, and the base The gear ratio m3 of the base ST3 is set to 1.5, and the gear ratio m4 of the base ST4 is set to 2.0. In FIG. 1, the fourth base ST4 is omitted.
Since the equidistant positioning mechanism according to one embodiment of the present invention is configured as described above, when the spline shaft 5 is rotated, the drive gear 3 of each base rotates at the same rotation speed. On the other hand, the driven gear 4 rotates on the ball screw 6 at each rotation speed according to the gear ratio with respect to the drive gear 3. As a result, the housing 2 rotates on the linear guide 1 in accordance with the rotational speed of the driven gear 4.
[0016]
Further, as described above, the gear ratio of each of the bases ST1, ST2, ST3, ST4,... Is m1: m2: m3: m4: ... = 1: 2: 3: 4: ... Therefore, the bases ST1, ST2, ST3,... Move on the linear guide 1 so that the distance (pitch) between adjacent bases is always equal.
Here, the principle will be briefly described with reference to FIG. First, one pitch obtained by dividing the straight line L ₀ (length L ₀ ) connecting the two points o and pn into n equal parts (n = 5 in FIG. 3) is defined as l _0, and the point dividing the straight line L ₀ into n equal parts is p 1. , P2, p3, and p4. At this time, of course, the following formula (1) is established.
[0017]
l ₀ = L ₀ / n (1)
Next, consider a case where the straight line L ₀ is changed (extended) to a straight line L ₁ (length L ₁ ) connecting the points o and p′n. Points that divide the straight line L ₁ into n equal parts (that is, destinations of the points p1, p2, p3, and p4) are points p′1, p′2, p′3, and p′4, and the straight line L ₁ is divided into n etc. Let l ₁ be the pitch to be divided. At this time, when the change amount of the pitch is x, the following equation (2) is established.
[0018]
l ₁ = l ₀ + x (2)
Here, the increment of the distance between the pitches is x, but the amount of movement of each point increases as the distance from the origin increases. That is, the amount of movement from p1 to p′1 is x, but the amount of movement from p2 to p′2 is the increment x of the distance between the pitches, and the amount of movement x from p1 to p′1. Since they are added, the total is 2x.
[0019]
Also, regarding the movement amount from p3 to p'3, the increase in the distance between the pitches is x, but since the movement amount 2x from p2 to p'2 is added, it is 3x.
Therefore, in order to move each of p1, p2, p3, and p4 (corresponding to the bases ST1, ST2, ST3, and ST4) at an equal interval, the movement amount of p2 is set to the movement amount of p1. It may be set so that the moving amount of p3 is three times that of p1. Similarly, it may be set so that the amount of movement of p4 is four times the amount of movement of p1.
[0020]
Generally speaking, this can be set so that the nth base counted from the origin is n times the amount of movement of the first base.
Therefore, in the equally spaced positioning mechanism of the present invention, the gear ratios m1, m2, m3, m4,... Of each base are set to m1: m2: m3: m4:. It is set to be 3: 4:. As a result, when the spline shaft 5 rotates, the amount of movement of the driven gear 4 becomes 1, 2, 3 and 4 times in order from the base on the origin side, and each base always maintains an equally spaced state. It moves while.
[0021]
Therefore, according to the equally-spaced positioning mechanism according to the embodiment of the present invention, the distance between the bases can always be kept equal, and the length of the workpiece is changed by the jig provided on the base. Even so, there is an advantage that positioning at equal intervals can be easily performed. This also has the advantage that the cycle time during the component mounting operation can be reduced and the efficiency of the operation can be improved.
[0022]
In addition, since the structure of this equidistant positioning mechanism is simple, there is an advantage that this mechanism can be provided at low cost, and there is an advantage that highly accurate positioning can be performed.
The equidistant positioning mechanism of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, a general trapezoidal screw may be used as the screw shaft instead of the ball screw. Moreover, you may apply a rotating shaft other than a spline shaft. For example, it is possible to apply a rotating shaft having a uniform protrusion in the axial direction. In this case, an engagement groove (key groove) that engages with the protrusion may be formed in the drive gear. Thus, it is possible to allow movement in the axial direction while allowing the drive gear and the rotation shaft to rotate integrally. In addition, other structures may be applied as long as the configuration prohibits relative rotation between the drive gear and the rotating shaft and allows relative movement in the axial direction.
[0023]
Further, a servo motor may be used as a drive source for the rotation shaft 5, or an operator may manually rotate the rotation shaft 5.
When the servo motor is used, there is an advantage that accurate position control can be executed by one servo motor, and there is an advantage that cycle time can be further reduced. Further, since only one servomotor is required, an increase in cost can be suppressed as much as possible. Further, when the operator manually rotates the spline shaft 5, there is an advantage that the cost can be further reduced.
[0024]
【The invention's effect】
As described above in detail, according to the equally spaced positioning mechanism of the present invention, there is an advantage that the equally spaced positioning can be easily performed, and positioning can be performed with high accuracy. This also has the advantage that the cycle time during the component mounting operation can be reduced and the efficiency of the operation can be improved. Further, since the structure is simple, there is an advantage that the present mechanism can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing a main configuration of an equally spaced positioning mechanism according to an embodiment of the present invention.
FIGS. 2A to 2D are schematic front views showing the main configuration of an equally spaced positioning mechanism according to an embodiment of the present invention.
FIG. 3 is a view for explaining the operating principle of an equally spaced positioning mechanism according to an embodiment of the present invention.
FIG. 4 is a schematic view showing a rear door hinge of a general truck cargo box (container).
[Explanation of symbols]
2 Housing (holding member)
3 Drive gear 4 Driven gear 5 Spline shaft (rotating shaft)
6 Ball screw (screw shaft)

Claims (1)

A rotating shaft that rotates by a rotational driving force from a driving force source;
A drive gear that rotates integrally with the rotating shaft and that can be moved back and forth with respect to the axial direction of the rotating shaft;
A screw shaft fixed at a position parallel to the rotation axis;
A driven gear meshing with the drive gear and screwed with the screw shaft;
A gear mechanism comprising the drive gear and the driven gear;
A plurality of sets of the gear mechanisms are arranged at equal intervals along the axial direction,
The gear ratio between the nth drive gear and the driven gear is n times the gear ratio between the first drive gear and the driven gear provided on one end side of the plurality of sets of gear mechanisms. An equal interval positioning mechanism characterized in that gear ratios of all sets of drive gears and driven gears are set.

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