JPH0356862B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a transfer bar drive device for conveying a workpiece to a machine tool and a protection device for this drive device.

``Conventional technology'' Recently, mechanical transfer devices have been attracting attention in order to shorten idle time and improve productivity when driving transfer bars in a linear direction to convey workpieces to each machine tool. There is.

Examples of conventional mechanical drive devices for transfer bars include those disclosed in Japanese Patent Application Laid-open No. 58-118367 or 1982-11836, or those using a single string movement mechanism or a cycloid movement mechanism. .

The above-mentioned publication describes a system that uses a gear train having a crank mechanism that moves at an inconstant speed, and causes a rack provided on the transfer bar to mesh with the gears constituting the crank mechanism to move the transfer bar vertically and drive the transfer bar forward and backward. It is shown.

``Problems to be Solved by the Invention'' However, in these conventional transfer bar drive devices, the drive point of the transfer bar changes every moment, and the drive bar swings up and down or left and right. It is necessary to intervene with a moving body.

In addition, in the systems shown in Figures 1 and 2, the drive stroke is determined by the circumferential length of the drive gear or by the third stroke.
Since it is determined by twice the crank radius shown in the figure, the stroke is usually expanded via a lever in order to obtain a predetermined stroke.

These methods require different amounts of space, and are mechanically large-scale, contributing to high costs.

Further, these conventional transfer bar drive devices have a problem in that there is no protection device for the drive device in the event that the transfer bar collides or becomes unable to move for some reason.

The present invention was made in view of these conventional problems, and utilizes a gear train based on a planetary gear mechanism to achieve linear motion without rocking the drive bar, is compact, and provides maximum stroke. It is an object of the present invention to provide a transfer bar drive device and a protection device for this drive device.

"Means for Solving the Problems" The gist of the present invention for achieving the above object is a transfer bar drive device using a gear train, which fixes a drive gear and rotates it by a drive source. a drive shaft pivotally supported on a base; a driven gear meshing with the drive gear rotatably supported on the base;
A swinging arm is rotatably supported on the axis of the drive shaft, and a second planetary gear is provided at one end of the swinging arm on the same axis as the first planetary gear meshing with the drive gear, A long groove is formed in the radial direction at the other end of the swing arm, and an engager protruding from a position eccentric from the rotation axis of the driven gear is slidably fitted into the long groove, and the second planetary An output shaft on which an output internal gear that meshes with the gear is fixed is pivoted on the base on the same axis as the drive shaft, and a shear pin that can be cut when a predetermined force or more is applied to the output shaft is provided. By fixing a transmission gear through the transmission gear and providing a rack so that driving force is transmitted from the transmission gear to the transfer bar, when an abnormal condition occurs in the transfer bar, the shear pin is cut off and the drive source is disconnected. The present invention relates to a transfer bar drive device characterized in that the transmission of the transfer bar is cut off.

``Function'' The input rotation at a constant speed is converted into an inconstant speed by the differential gear movement by the swing arm, and is taken out to the output gear concentric with the drive gear, and then linearly moved by the transmission gear and the rack. It can be transmitted to the transfer bar by converting it into
Also, when an abnormality occurs on the transfer bar side, the shear pin that protects the drive device is disconnected.

“Embodiment” An embodiment of the present invention will be described below based on the drawings. Note that similar parts in each embodiment are designated by the same reference numerals, and redundant explanation will be omitted.

4, 5 and 6 show embodiments of the invention.

As shown in FIG. 5, a drive shaft 20 is pivotally supported on the base 10, a worm wheel 21 for input and a drive gear 30 are fixedly attached to the drive shaft 20, and a swing arm 40 is freely rotatable. A worm 11 connected to a drive source is engaged with the worm wheel 21.

A planetary gear 50 that meshes with the drive gear 30 is fixed to a pivot shaft 51 at one end of the swing arm 40, and a planetary gear 52 for output output is fixed to one end of the pivot shaft 51 of the planetary gear 50. A long groove 41 in the radial direction is formed at the other end of the swing arm 40 .

A driven gear 60 adjacent to the drive shaft 20 and meshing with the drive gear 30 is rotatably supported on the base 10 via a subshaft 61. A shaft pin 62 is provided in a protruding manner at a position eccentric by a radius r, and is fitted into the long groove 41 of the swing arm 40 via an engaging element 63 so as to be swingable.

An output shaft 12 is pivotally supported on the base 10 concentrically with the drive shaft 20, and the output shaft 12 has a planetary gear 52 integrally connected to the output shaft 52 via a planetary gear 50 and a pivot shaft 51.
An output internal gear 70 that meshes with the transfer bar A is fixed, and a transmission gear 13 is also fixed, and the transmission gear 13 is meshed with the rack A1 of the transfer bar A.

In the transfer bar drive device having the above configuration, the input rotation is driven by the worm 11 to the drive gear 30 through the worm wheel 21 and the drive shaft 20, and the planetary gears 50 and 52 are rotated to rotate the output internal gear 70, The rotation is transmitted to the output shaft 12 connected thereto.

At the same time, the driven gear 60 also rotates, and the shaft pin 62, which is provided at a position eccentric from the center of rotation, moves circularly. This shaft pin 62 is rotatably inserted into an engaging element 63 that is slidably engaged in the long groove 41 of the swing arm 40.

Since this engaging element 63 slides in the long groove 41 and causes the swing arm 40 to swing around the drive shaft 20, the planet gear 50 performs a differential gear movement between the drive gear 30 and the planet gear 52. , output internal gear 70
Inconstant speed rotation is transmitted to the output shaft 12 via.

Now, the shaft pin 62 is connected to the driving gear 30 and the driven gear 60.
Since the speed of the swinging arm is highest when starting from the extension line of the center line connecting the centers of If the eccentric radius r of the shaft pin 62 is set at a position such that the initial speed of the output internal gear becomes zero due to the combined speed of the differential motion between the output internal gear 70 and the gear 30, the output internal gear 70 can be moved from an initial speed of zero to zero. The shaft pin 6 of the driven gear 60 is gradually accelerated.
2 reaches its maximum speed at a position rotated by 180 degrees, and then gradually decelerates until the driven gear 60 rotates once and the shaft pin 62 quietly stops at a position of 360 degrees.

This movement is transmitted to the drive bar A via a transmission gear 13 fixed to the output shaft 12.

The stroke of the drive bar A is 1 of the driven gear 60.
It is determined by the rotation speed of the output shaft 12 and the diameter of the transmission gear 13.

That is, the input is from the drive shaft 20 (or the subshaft 61), but one cycle on the output side is from the driven gear 60.
It is determined by one rotation of .

The stroke S of the drive bar A is calculated from the following equation.

Now, the number of teeth of the driving gear 30 is Z ₁ , the planetary gear 50,
The number of teeth of the internal gear 70 is Z ₂ , Z ₃ , the number of teeth of the internal gear 70 is Z ₄ ,
The number of teeth of the driven gear 60 is _Z5 , and the number of teeth of the transmission gear 1 is
3, the number of teeth is Z ₆ , the gear ratio is n, the module is M, and the pitch circle diameter of the gear is D. Z ₄ = Z ₁ + Z ₂ + Z ₃ ...(1) n = Z ₅ /Z ₄ − Z ₃ /Z ₂ …(2) S=π・M ₆・Z ₆ ×n=π・D ₆・n …(3) For example, the diameter of the transfer bar transmission gear 13
Example 1 ^Z ₁ = 40 ^T , Z ₂ = 20 _T , Z ₃ = 40 ^T , Z ₄ = 100 ^T ,
Z ₅ = 80 ^T Example 2 Z ₁ = 49 ^T , Z ₂ = 20 ^T , Z ₃ = 30 ^T , Z ₄ = 99 ^T , Z ₅
=66 For two types of gear trains of ^T , the stroke S of the drive bar is Example 1 n ₁ =80/100×40/20=1.6 S ₁ =π・D ₆・n=3.14159
×300×1.6=1507.96mm Example 2 n ₂ = 66/99×30/20=1 S ₂ =π・D ₆・n=3.14159×300×1=
942.48mm In this way, the stroke of the drive bar A can be changed even with the same transmission gear diameter by changing the gear ratio of the gear train.

On the other hand, in order to obtain the same stroke, the gear train of Example 1 requires a transmission gear diameter 1/1.6 smaller than that of Example 2, resulting in a more compact device.

(1) Setting the eccentricity of the shaft pin 62 From FIG. 4, the rotation angle of the driven gear 60 is θ, the distance between the center of the subshaft 61 that supports the driven gear 60 and the center of the drive gear 30 is a, and the planetary If the distance between the pivot 51 of the gear 50 and the center of the drive gear 30 is b, and the symbols of other parts are set as shown in FIG. 4, the swing angle ψ of the swing arm 40 is ψ=-tan. ^-1 (λsinθ/1−λcosθ) …(4).

However, λ=r/a The angular velocity ω ₈ of the swing arm 40 is ω ₈ = dψ/dt=−λ(cosθ−λ)/1−2λcosθ−λ ²
×ω ₅ …(5) Axial center movement speed (initial speed) of planetary gears 50, 52
V ₁ is, V ₁ = ω ₈ ×b = −λ (cosθ−λ) ω ₅ /1−2λcosθ+
λ ² b...(6) The circumferential speed v ₀ of the drive gear 30 is, when its rotational speed is N ₁ , V ₀・π・D ₁・N ₁ = π・D ₅・N ₅ = 30・D ₅・ω ₅
(m/min) ...(7) The relative circumferential speed of the planetary gear 50 due to the planetary motion is v ₂
If the circumferential speed of the virtual gear 50a, which is assumed to mesh with the outside of the planetary gear 50, is v' ₂ , then the starting condition for the virtual gear 50a is v' ₂ = v ₀ - (v ₁ + v ₂ ),
v′ ₂ =0. Of course, if the internal gear 70 is directly decelerated or accelerated by the planetary gear 50, in order for the virtual gear 50a to start and stop at zero, it is necessary to correct the deceleration or speed increase ratio. That is, the peripheral speed v ₄ of the internal gear 70 is 0.
In order to start, the difference in speed of the planetary gear was corrected based on the conditions for _V3 to start at 0. The relationship shown in equation (8) is required.

V ₀ - (1 + (J + 1) / J) (V ₁ + V ₂ ) = 0 ... (8) Assuming that v ₁ = v ₂ , from formulas (6) and (7), (Figure 5) 30・D ₅・ω ₅ /60−(J+1)×λ(cosθ−λ)ω ₅ /1−2λcosθ+λ ₂ ×b=0…
…(9) Assuming θ=0, λ={2D ₅ +2(J+1)b}−√{2D ₅ +2(J+1)
b} ² −4{D ₅ +2(J+1)b}×D ₅ /2{D ₅ +2(
J+1)b}...(10) r=a×λ...(11) Therefore, the eccentricity r of the shaft pin 62 for the circumferential speed _v4 of the internal gear 70 to start at 0 is (10), (11 ), r={2D ₅ +2(J+1)b}−√{2D ₅ +2(J+1)
b} ² −4{D ₅ +2(J+1)b}D ₅ /2{D ₅ +2(J
+1)b}...(12) However, D ₁ is the pitch diameter of the drive gear 30 (2) The speed V of the gear 70 is the equivalent rotational speed of the swing arm 40 N ₈ : N = 30ω ₂ /π Rotation of the planetary gear shaft The number N ₂ is N ₂ = (1 + Z ₁ / Z ₂ ) N ₈ - _{Z 1} / Z ₂ N ₁ ... (13) However, N ₁ = 60/T (rPm) T: Pitch radial peripheral speed v of the time gear 52 ₃ is V ₃ = π・D ₂・N ₂ /60(m/sec)...(14) The pitch radial peripheral speed V of gear 70 is V=v ₁ +v ₃ =60×b・ω ₅ (cosθ6−λ )λ/1−2λcosθ+λ ² +π・D ₃ {(Z ₁ +Z ₂ )N ₈ −Z ₁ N ₁ /Z ₂ }(m/sec) ...(15) Angular velocity of gear 70 ω ₄ (Figure 7) ω ₄ =2V/D ₄ ×60=2・b・ω ₁ (cosθ−λ)λ/D ₄ (1
−2λcosθ＋λ ² ) +π・D ₃ /30・D ₄ {(Z ₁ +Z ₂ )N−Z ₁ N ₁ /Z ₂ }(rad/s
e c) ...(16) (3) Acceleration The acceleration A of the pitch diameter of the internal gear 70 is A=dv/dt=dv ₁ /dθ・dθ/dt+dv ₃ /dθ・dθ/dt=ω ₅・λ・sinθ (1−λ ² )/(1−2λcosθ+λ ²
) ² (b+D ₃ (Z ₁ +Z ₂ )/2Z ₂ )・ω ₅ (m/sec ² ) ...(17) The angular acceleration x of the gear 70 is (Fig. 8) x=2A/D ₄ (rad /sec ² ) ...(18) (4) The displacement s of the gear 70 is The displacement S of the pitch diameter of the gear 70 has the following relationship from Fig. 5.

S=J・l+J・l ₁ +l ₂・(mm) ...(19) However, if the movement is clockwise (+) and counterclockwise (-), the reduction ratio of the planetary gears 50 and 52 is J. do.

Now, when the planetary gears 50 and 52 are on the left side of the gg line, the displacement of the pitch circle diameter of the output internal gear 70 is expressed by the following equation.

S=1/J・θ/360°・π・D ₅ +1/J・ζ・D ₁ /2+ζ・D ₄ /2 (mm)……(20) Angular displacement Y of gear 70 Y=S・180/ π・1/R=360・S/π・D ₄ (degrees) ...(21).

From the above formula, displacement ST and speed on the drive bar
VT and acceleration AT are expressed by the following formula.

ST=D ₆ /D ₄・S=Z ₆ /Z ₄・S =D ₆ /D ₄ {1/2(θ/180×J・π・D ₅ +ζ ₁・D ₁ /
J+ ζ・D ₄ )} ...(22) VT=D ₆ /2・ω ₄ ×60=D ₆ /D ₄・V ......(23) AT=D ₆ /D ₄・A ......(24) When the gear train of Example 1 is applied to the above equation, Figure 7 shows
A speed characteristic curve as shown in FIG. 8 is obtained.

The acceleration curve becomes a modified sine curve, and a speed suitable for conveying heavy objects can be obtained.

Therefore, the operation is transmitted from the output internal gear 70 via the output shaft 12, the transmission gear 13, and the rack A1, and the transfer bar A changes depending on the angular velocity and acceleration of the output internal gear 70.
is driven linearly and vertically.

Therefore, the input rotation at a constant speed is converted to inconstant speed by the differential gear movement by the swing arm, is taken out to the output gear concentric with the drive gear, and is converted into linear force by the transmission gear and rack. can be transmitted to the transfer bar.

"Effects of the Invention" The transfer bar driving device according to the present invention has the following effects.

The conveying speed characteristic is a modified sine curve suitable for conveying heavy objects, so objects can be conveyed in a short time without impact.

Since the rotation angle is changed to linear motion, the conveyance stroke can be selected simply by the size of the conveyance gear without changing the inside of the drive device.

Conveyance speed control is performed by speeding up, decelerating, and stopping within one revolution of the oscillating gear, but the speed of the output shaft is controlled within a total revolution.

In other words, in order to produce the same stroke of 1200 mm when the output shaft rotates 1 rotation for 1 rotation of the oscillating gear and when it rotates 1.6 rotations with the combination of gears Z ₁ to Z ₅ , the size of the conveyor gear is φ382 mm. For,
With a diameter of 239 mm, the device can be compactly assembled.

Since the drive bar of this device moves only in a straight line, it does not swing like in the past, so there is no need for a carriage or an expansion lever, and it can also be installed at a position offset from the conveyance line as in the past. Since it can be installed within the conveyance line without any need for a conveyance system, it is possible to carry it through the conveyance line, saving floor space occupied by the device.

By attaching multiple conveyance gears to the output shaft, multiple conveyance strokes can be issued simultaneously.

Since the shear pin is provided on the transfer bar side, the drive device can be protected in the event of an abnormality.

This device, which has the features described above, uses a combination of an oscillating slider crank mechanism using oscillating gears and a planetary gear mechanism to silently start constant speed rotation of the input shaft from a stopped state on the output shaft, and achieve smooth acceleration and deceleration. The rotational motion is again changed to a quiet stop, and this is then converted into linear motion using a rack and pinion, eliminating the impact caused by inertia and enabling high-speed conveyance. Furthermore, it has the effect of protecting the drive device when an abnormality occurs on the transfer bar side.

[Brief explanation of drawings]

1, 2 and 3 show conventional transfer bar drive devices. 4 is a cross-sectional view schematically showing the gear train that constitutes the device, FIG. 5 is a longitudinal sectional view of the device, FIG. 6 is a sectional view taken along line A-A in FIG. 5, and FIGS. The figure is a diagram showing operating characteristics. A...Transfer bar, A1...Rack, 10...
Base, 13... Transmission gear, 20... Drive shaft, 30
... Drive gear, 40 ... Swing arm, 41 ... Long groove, 5
0, 52... Planetary gear, 60... Driven gear, 62... Shaft pin, 63... Engagement element, 70... (Internal gear for output) gear, 80... Gear case, 81... Backup roller, 82... Shear pin.

Claims (1)

[Scope of Claims] 1. A transfer bar drive device using a gear train, which comprises: a drive gear is fixedly mounted, a drive shaft rotated by a drive source is pivotally supported on a base, and a driven gear meshes with the drive gear. A gear is rotatably supported on the base, a swinging arm is rotatably supported on the axis of the drive shaft, and a first planet that meshes with the drive gear is attached to one end of the swinging arm. A second planetary gear is provided on the same axis as the gear, a long groove is formed in the radial direction at the other end of the swing arm, and an engager protruding from a position eccentric from the rotation axis of the driven gear is provided in the long groove. An output shaft, on which an output internal gear that is slidably fitted and that meshes with the second planetary gear is fixed, is pivotally supported on the base on the same axis as the drive shaft; By fixing the transmission gear via a shear pin that can be cut when a force exceeding a predetermined level is applied, and providing a rack so that the driving force is transmitted from the transmission gear to the transfer bar,
A drive device for a transfer bar, characterized in that when an abnormal state occurs in the transfer bar, the shear pin is cut off to cut off transmission from a drive source.