JP2006266398A - Sequentially driving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sequentially driving device capable of suppressing play to small extent and realizing stable positioning operation at high speed with high precision. <P>SOLUTION: When the number of Geneva driven wheels having the number m of channels 501a, 501b is k and the number of original wheel pins 510a, 510b for driving the Geneva driven wheels is n in this sequentially driving device having a configuration for driving a plurality of Geneva driven wheels 50a, 50b sequentially using one Geneva original wheel 51, an angle between the Geneva driven wheels is η, an angle between the Geneva original wheel pins is α, and α≠360°/n in a configuration for satisfying kηn=360°, wherein η=180°-360°/m n≥2, k≥2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sequential drive device using a Geneva mechanism for sequentially operating and stopping a plurality of driven objects.

  Conventionally, a configuration in which one Geneva slave is controlled by one Geneva original vehicle is known (see, for example, Patent Document 1). In this example, since a configuration having a plurality of Geneva original vehicle pins in one Geneva original vehicle is adopted, sequential operation is not aimed. In addition, the pins are arranged at symmetrical positions to ensure a Geneva cam surface fit for both the Geneva original vehicle and the slave vehicle, and have a configuration with little play.

Japanese Patent Laid-Open No. 10-181992

  However, if a Geneva base pin is symmetrically arranged to drive a plurality of Geneva slaves using a single Geneva master vehicle with a Geneva mechanism known in the prior art, the cam of the Geneva slave vehicle as shown in FIG. Since the position where the surface 500b is in contact with the Geneva original vehicle cam surface 511 is close to the straight line connecting the axes, it can be confirmed that the deflection angle (backlash) is large. That is, the cam surface fitting of the Geneva master vehicle and the Geneva slave vehicle decreases, and the play of the Geneva slave vehicle increases. Furthermore, in this case, the influence of the cam surface machining accuracy is greatly affected, and it becomes difficult to maintain a stable stopping accuracy.

  Therefore, for example, when two Geneva slaves with four grooves arranged at 90 ° phase are driven using one Geneva master vehicle, a sufficient cam surface fitting amount between the Geneva master vehicle and the Geneva slave vehicle is secured. In the stop position, it is necessary to dispose the Geneva vehicle pin at a position away from the two Geneva slave grooves. As a result, in this configuration, only one pin can be arranged in the Geneva master vehicle, and it is necessary to sequentially operate and stop the two Geneva slave vehicles by one rotation of the Geneva master vehicle.

  However, in this case, the operations of the two Geneva slave vehicles end at the Geneva master vehicle 180 °. However, since the Geneva master vehicle needs to be further rotated 180 °, it is difficult to increase the operation speed. Increasing the rotational speed of the Geneva original vehicle increases the load on the drive source, making it difficult to reduce the size of the machine and save energy.

  In order to sufficiently secure the cam surface, it is conceivable to arrange the Geneva follower at a 180 ° phase as shown in FIG. By doing so, the cam surface 511 of the Geneva original vehicle can suppress the deflection angle (backlash) by suppressing the Geneva slave vehicle cam surface 500b over the entire surface.

  However, in this configuration, the two Geneva slaves are driven at the same time, and sequential driving cannot be realized.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a sequential drive device capable of realizing high-speed, high-accuracy and stable positioning operation with small play.

To achieve the above object, the present invention provides a sequential drive device using a configuration in which a plurality of Geneva slaves are sequentially driven using one Geneva original vehicle.
When the number of Geneva slaves having m grooves is k, and the number of original vehicle pins driving the Geneva slave is n,
kηn = 360 °
However,
η = 180 ° -360 ° / m
n ≧ 2, k ≧ 2
In the configuration satisfying the above, the angle between the Geneva follower vehicle is η, and the Geneva original vehicle pin angle α is
α ≠ 360 ° / n
It is characterized by.

  According to the present invention, when the Geneva original vehicle stops at the first stop position, the pin fits into the Geneva slave vehicle groove, and the play of the Geneva slave vehicle is kept small. Further, in the state of stopping at the second stop position, the backlash can be kept small by increasing the angle at which the cam surface of the Geneva master vehicle and the Geneva slave cam surface are in contact with each other. Operation can be realized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
Embodiment 1 is shown in FIG.

  The Geneva master vehicle 51 has a configuration in which two pins 510a and 510b are arranged in the phase α to drive the two Geneva slave vehicles 50a and 50b.

  The Geneva slave vehicles 50a and 50b are installed at a 90 ° phase with respect to the Geneva master vehicle 51, and when the Geneva master vehicle 51 is rotated 180 ° clockwise (counterclockwise) by a drive source (not shown), the Geneva slave vehicle first. 50a (50b) is rotated, and then the Geneva follower 50b (50a) is rotated to sequentially drive and stop in the next stop state shown in FIG.

  In the state of FIG. 1, the play of the Geneva followers 50a, 50b is determined by the fitting of the pins 510a, 510b of the Geneva original vehicle and the grooves 501a, 501b of the Geneva follower.

  In FIG. 1, the basic radius (R) of the Geneva mechanism, the angle (α2) at which the Geneva original vehicle pin 510 engages with the Geneva follower groove 501 and the play (g) of the original vehicle pin 510 and the follower groove 501 shown in FIG. Is used as a variable, and the play angle (γ) of the Geneva follower is obtained as follows.

γ = cos ⁻¹ (1, g ² / (2Rs ² ))
However, Rs of the above formula is obtained from FIG. 5 which is a simplified view of the state where the Geneva original vehicle pin is fitted to the Geneva slave groove at the fitting angle (α2).
Rs ² R ² + 2R ² -2√2R ² os (π / 4-α2)
It becomes.

  At this time, the angle (δ) deviated from the normal position by fitting the Geneva follower wheel 50 with the original vehicle pin 510 is as follows.

δ = π / 4-cos ⁻¹ ((R ² + Rs ² ) / (2√2RRs))
In addition, in the state of FIG. 2, the play of the Geneva slave vehicle 50 is determined by the Geneva master vehicle cam surface 511 and the Geneva slave vehicle cam surfaces 500a and 500b coming into contact with each other.

  In the state of FIG. 2, a simplified model of the Geneva mechanism shown in FIG. 3 is used in order to obtain a backlash when the original vehicle cam surface 511 and the slave vehicle cam surface 500 b are in contact with each other.

  The basic radius (R) of the Geneva original vehicle and the Geneva slave vehicle, the distance between the axes of the Geneva original vehicle and the slave vehicle (√2R), the Geneva original vehicle cam surface radius (R1), the Geneva slave vehicle cam surface radius (R2), the Geneva When the boundary point (P) of the original vehicle cam surface 511 and the original vehicle cam angle (α1) of the angle between the straight line between the original vehicle and the driven vehicle shaft are used as variables, the Geneva follower backlash angle (θ) is obtained as follows.

θ = cos ⁻¹ ((R ² + 2R ² −R2 ² ) / (2√2RpR)) · β
However, Rp and β are obtained from the simplified model of FIG. 3 in which the cam surface of the Geneva original vehicle and the cam surface of the Geneva slave vehicle are in contact with each other.
Rp ² R1 ² + 2R ² -2R1R√2 cos (α1)
β = sin ⁻¹ (R1sin (α1) / Rp)
It is.

  Here, if the Geneva master pin 510 is fitted within a range where the angle (γ + δ) that is displaced when the Geneva master pin 510 is fitted to the Geneva master groove 501 is not more than the cam surface contact play (θ), the play of the entire mechanism can be kept small. Can do.

  Here, assuming that R = 20 mm, the inter-axis distance, cam surface radius dimensional accuracy is ± 0.05 mm, and the inter-cam nominal play is 0.03 mm, when R1 = 15 mm, R2 = 15.18 mm. The play (g) between the Geneva master pin 510 and the Geneva follower groove 501 is 100 μm, the play angle (γ) of the Geneva follower, the deviation angle (δ) of the Geneva follower, and the play back angle (θ) of the Geneva follower. Are summarized in the tables of FIGS.

  As a result, when the fitting angle (α2) increases, the play angle (γ) of the Geneva slave vehicle increases, and when the Geneva master vehicle cam angle (α1) increases, the Geneva follower play angle (θ) decreases. It can be confirmed.

  However, the following relationship is established between the Geneva original vehicle cam angle (α1) and the angle (α2) at which the original vehicle pin fits into the groove.

α1 = α2 + Δ
Here, Δ is a constant specific to the Geneva mechanism as shown in FIG. 8 and is determined by the shape and arrangement of the Geneva mechanism. In a general Geneva mechanism, it is considered that Δ = 0.

Geneva follower backlash angle (γ + δ) generated due to the total displacement amount (γ + δ) of the Geneva follower wheel 50 due to the fitting of the Geneva master wheel pin 510 and the Geneva follower groove 501 when Δ = 0. When the total deviation amount of θ) is confirmed in the tables of FIGS. 6 and 7,
10 ° <α1 = α2 <12.5 °
(Γ + δ) = θ
It can be confirmed that there exists an equilibrium point.

  In addition, in the stop state 1 shown in FIG. 1, it can be confirmed that as the fitting angle (α2) increases, the backlash (δ) and the amount of deviation (γ) from the normal position increase.

  Furthermore, in the stop position 2 state shown in FIG. 2, it can be confirmed that the play (θ) decreases as the Geneva original vehicle cam angle (α1) increases.

  That is, it is desirable to make α2 as small as possible and α1 as large as possible. In order to suppress both backlashes at the same time (γ + δ), it is necessary to simultaneously minimize θ.

  Since Δ> 0 can be realized by devising the shape of the Geneva mechanism in Δ, the fitting angle (α2) between the Geneva original vehicle pin 510 and the Geneva follower groove 501 is balanced in order to minimize the play of both. It is desirable to keep it below 10 ° near the point.

<Embodiment 2>
FIG. 10 shows the second embodiment.

  In the present embodiment, the Geneva master vehicle pin 510 is arranged in a 180 ° phase, and the Geneva slave vehicles 50a and 50b are installed in an α3 phase.

  With this configuration, the angle (α2) at which the Geneva master vehicle pin 510 is fitted to the Geneva slave groove is constant, and the normal position deviation angle (δ) of the Geneva slave vehicle 50 and the Geneva slave vehicle play angle ( γ) is the same as the equation in the first embodiment.

  In order to keep it below the Geneva follower backlash angle (θ) due to the cam surface contact, the angle α3 needs to be 90 ° or more and 110 ° or less.

  However, in this embodiment, since the play angle (γ) of the Geneva slave wheel can be kept small, the fitting angle (α2) can also be determined from the normal displacement amount (δ).

<Embodiment 3>
FIG. 11 shows a third embodiment.

In the present embodiment, two Geneva followers 50a and 50b having three grooves are used. When m = 2 (number of Geneva grooves) and k = 2 (number of Geneva followers),
η = 180 ° / 360/3 = 60 °
Thus, the Geneva follower is arranged at 60 ° phase.

At this time, from kηn = 360 °,
n = 3
Thus, the number of Geneva original vehicle pins 510 is three.

The angle α between the original vehicle pins is
α ≠ 360 ° / n = 120 °
The angle between the two pins is α5, and the other pin angle is α4 (α4 ≠ α5).

  In this state, as shown in FIG. 11, in the inter-pin angle α4 state, the original vehicle pin 510 is fitted into the follower groove 501 and the play of the Geneva follower 50 is suppressed.

  Further, as shown in FIG. 12, in the state of the pin angle α5, the contact amount between the cam surfaces 511 and 500 is increased, and the play is suppressed.

It is a figure which shows the Geneva original vehicle pin and Geneva follower groove | channel fitting state in Embodiment 1 of this invention. It is a figure which shows the Geneva original vehicle cam surface and Geneva slave vehicle cam surface contact state in Embodiment 1 of this invention. It is a Geneva original vehicle pin and a Geneva slave vehicle fitting state simplification figure. FIG. 5 is a detailed view of a Geneva original vehicle pin and a Geneva follower groove fitting backlash. It is a simplified view of the contact state of the Geneva original vehicle cam surface and the Geneva slave vehicle cam surface. It is a backlash table | surface at the time of a Geneva master vehicle pin and Geneva slave wheel groove fitting. It is a backlash | play table at the time of a Geneva original vehicle cam surface and a Geneva slave vehicle cam surface contact. It is a Geneva original vehicle pin symmetrical position arrangement drawing. It is a Geneva follower 180 degree phase arrangement diagram. It is a figure which shows Embodiment 2 of this invention. It is a figure which shows Embodiment 3 of this invention. It is a figure which shows Embodiment 3 of this invention.

Explanation of symbols

50a, 50b Geneva slave vehicle 51 Geneva master vehicle 510a, 510b Geneva master vehicle pin 501a, 501b Geneva slave vehicle groove 511 Geneva master vehicle cam surface 500a, 500b Geneva slave vehicle cam surface α1 Geneva master vehicle cam angle α2 Geneva master vehicle pin / Follower groove fitting angle θ Geneva follower backlash angle when cam surface comes in contact δ Geneva master car pin / follower groove fit angle Geneva follower backlash angle

Claims (3)

In a sequential drive device using a configuration that sequentially drives a plurality of Geneva slaves using one Geneva original vehicle,
When the number of Geneva slaves having m grooves is k, and the number of original vehicle pins driving the Geneva slave is n,
kηn = 360 °
However,
η = 180 ° -360 ° / m
n ≧ 2, k ≧ 2
In the configuration satisfying the above, the angle between the Geneva follower vehicle is η, and the Geneva original vehicle pin angle α is
α ≠ 360 ° / n
A sequential drive device characterized by that. Two Geneva slave vehicles with four grooves are controlled by using one Geneva master vehicle, the two Geneva slave vehicles are installed at a phase of 90 ° with respect to the Geneva master vehicle, and the two Geneva slave vehicles are driven. In the sequential drive device having the Geneva original vehicle having a pin,
When the phase of the two pins is α,
160 ° ≦ α <180 °
The sequential drive device according to claim 1, wherein the sequential drive device is installed in a phase that becomes In a sequential drive device using a configuration that sequentially drives a plurality of Geneva slaves using one Geneva original vehicle,
When the number of Geneva slaves having m grooves is k, and the number of original vehicle pins driving the Geneva slave is n,
kηn = 360 °
However,
η = 180 ° -360 ° / m
n ≧ 2, k ≧ 2
In a configuration satisfying the above, the phase τ between at least two Geneva slaves is
τ> η
A sequential drive device characterized by that.

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