JPH08290383A - Connection pin positioning mechanism - Google Patents

Abstract

PURPOSE: To connect a connection pin with high accuracy by providing a third plate to be held by (n) coil springs to be coiled around the upper and lower parts of (n) elastic rods and a fourth plate having a connection hole in which the connection pin is inserted to facilitate the analysis and the adjustment of the quantitative prediction of the restoring force. CONSTITUTION: The diameter of a hole for an elastic rod which is provided in a plate 2 to pass an elastic rod 4 is slightly larger than the diameter of the elastic rod, and the movement in the horizontal direction of the plate 2 is restricted by the elastic rod 4. The movement of a connection pin 6 in the inserting axial direction is restricted by the elongation of coil springs 5a, 5b. The tip of the connection pin 6 and a connection hole 10 are formed of the inclined structure to facilitate the insertion while the connection pin 6 and a connection plate 11 are simply inserted, and not fixed to each other. Because the positional error is generated between the connection pin 6 and an introducing hole due to the error of the control system in the connection, and the force to move the connection pin 6 toward the plate 3. But the plate 3 can be guided to the fixed position because the restoring force to return the connection pin 6 to the fixed position is applied due to the restoring force of the coil springs 5a, 5b and the elastic rod 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling pin positioning mechanism, and more particularly, to a coupling pin positioning mechanism that utilizes the restoring force of an elastic body to perform coupling with high positional accuracy.

[0002]

2. Description of the Related Art In recent years, automation of manufacturing by industrial robots has been popular, but, for example, when a connecting pin is inserted into a hole of a mating partner by a robot arm, it is necessary to compensate a position error of a robot control system. The positioning mechanism becomes important.
In particular, when a position error occurs, it is required to absorb this position error and to be able to combine with the other side with high position accuracy.

FIG. 4 is a partial sectional front view showing a conventional coupling pin positioning mechanism.

Referring to FIG. 4, a conventional coupling pin positioning mechanism is a plate 1 attached to an arm 8 of a robot or the like.
And a plate 3 having an introduction hole 7 having a diameter larger than that of the connecting pin 6, and four rigid rods 14 connecting the plates 1 and 3 together.
And four coil springs 5a wound around the upper half of the rigid rod 14 and wound around the lower half of each of the four rigid rods 4.
A coil spring 5b, a plate 12 having four large-diameter rigid rod holes 19 to which four rigid rods 14 can be attached to which the connecting pins 6 are attached, and a plate 12 sandwiched from above and below by the coil springs 5a and 5b; A coupling hole 10 into which 6 is inserted for coupling
And a coupling plate 11 having

Next, the operation will be described in detail with reference to FIG.

The plate 1 and the plate 3 are connected by four rigid rods 14. The plate 12 is located between the plates 1 and 3 and
It has four rigid bar holes 19 through which the rigid bar 14 of the book passes.

Since the plate 12 is sandwiched and supported by the upper four coil springs 5a and the lower four coil springs 5b supported by the rigid rod 14, the plate 12 can freely move within the range of expansion and contraction of the coil springs 5a and 5b. It is possible to move up and down.

The connecting pin 6 is attached to the plate 12 and has an integrated structure with the plate 12, so that the same operation is performed.

The diameter of the rigid rod hole 19 through which the rigid rod 14 provided in the plate 12 penetrates is larger than the diameter of the rigid rod 14, and the diameter of the introduction hole 7 of the plate 3 through which the connecting pin 6 penetrates. Since the diameter of the connecting pin 6 is larger than that of the connecting pin 6, the connecting pin 6 can move relative to the plate 3 in the plane perpendicular to the insertion axis of the connecting pin 6, that is, in the horizontal direction.

Further, the connecting pin 6 can be moved in the insertion axis direction by the deformation of the coil springs 5a and 5b. When the connecting pin 6 goes too far, it is returned to an appropriate position by the elastic restoring force of the coil springs 5a and 5b. . Here, the restoring force refers to a force that, when the elastic body is deformed, returns to a state before the deformation.

As described above, when the connecting pin 6 is inserted into the connecting hole 10 of the connecting plate 11 by the arm 8, the plate 1, the plate 3 and the rigid rod 14 are integrated with the arm 8 and have the same operation. Therefore, the plate 12 and the connecting pin 6 can be moved in the horizontal direction even if a positional error occurs in the operation of the arm 8, and the elastic restoring force of the coil springs 5a and 5b and the tip of the connecting pin 6 are effective. Is molded into a wedge-shaped inclined structure, a positional error is absorbed in both the horizontal direction and the insertion axis direction, so that the connection is performed with high positional accuracy.

FIG. 5 is an explanatory view showing a conventional restoring force.

As shown in FIG. 5, when the center axis 15 of the plate 12 and the center axis 16 of the plate 1 and the plate 3 are displaced by a positional error of δ, the coil springs 5a and 5b are bent as shown. Therefore, the central axis 15 of the plate 12 and the plates 1 and 3
The restoring force 21 (F) acts on the plate 12 so that the central axis 16 of the plate coincides with the center axis 16, that is, the position error δ becomes zero.

The quantitative prediction of the restoring force 21 when a position error occurs is performed by the rigid rod hole 1 in the positioning mechanism.
It is necessary to determine the diameters of 9 and the introduction hole 7, but the elastic coefficients in the axial direction of the coil springs 5a and 5b are known and clear, but the elastic coefficients in the bending direction are not known.
Quantitative prediction of 1 is difficult. Therefore, the difficulty in quantitatively predicting the restoring force 21 is dealt with by increasing the diameters of the rigid rod hole 19 and the introduction hole 7 in FIG.

[0015]

DISCLOSURE OF THE INVENTION The conventional connecting pin positioning mechanism described above relates to quantitatively predicting the restoring force of the connecting pin when a positional error occurs in a plane perpendicular to the connecting pin insertion axis, and the connecting pin insertion axis is used. The restoring force in the direction can be analyzed by clarifying the elastic coefficient of the coil spring in the axial direction.
The restoring force in the plane perpendicular to the insertion axis of the coupling pin is difficult to analyze due to the uncertain elastic modulus in the bending direction of the coil spring, and it is difficult to adjust the restoring force because it depends on the mutual relationship between the expansion and contraction of the four coil springs. It has the drawback that

An object of the present invention is to provide a coupling pin positioning mechanism that facilitates the analysis of quantitative prediction of the restoring force in the plane perpendicular to the insertion axis of the coupling pin and the adjustment of the restoring force to couple the coupling pin with high positional accuracy. It is in.

[0017]

SUMMARY OF THE INVENTION A connecting pin positioning mechanism according to the present invention comprises a first plate connected to a control shaft for positioning and a second plate having a hole having a diameter larger than the diameter of a connecting pin passing therethrough. And n elastic rods that connect the first plate and the second plate, 2n coil springs that are independently wound up and down on each of the n elastic rods, and the coupling. N pins which have pins attached and which have holes of a size that fits the diameters of the n elastic rods through which the n elastic rods can penetrate, and which are wound at positions above the n elastic rods. A third plate sandwiched between the coil spring and the n coil springs wound around the lower part of the n elastic rods, and a coupling hole into which the coupling pin is inserted for coupling. And a fourth plate.

Further, it is characterized in that the n elastic rods are four and the n holes of the fourth plate are four.

The fourth plate is characterized in that it has a hook for fixing the connection between the second plate and the fourth plate.

[0020]

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

FIG. 1 is a partial sectional front view showing an embodiment of a coupling pin positioning mechanism of the present invention.

The connecting pin positioning mechanism of this embodiment shown in FIG. 1 has a plate 1 attached to an arm 8 of a robot or the like, and a plate 3 having an introduction hole 7 having a diameter larger than that of the connecting pin 6.
And four elastic rods 4 connecting the plate 1 and the plate 3, four coil springs 5a wound around the upper half of the elastic rod 4 on each of the four elastic rods 4, and wound around the lower half. The coil spring 5 has four coil springs 5b and four elastic rod holes 9 each having a diameter large enough to fit the four elastic rods 4 to which the connecting pins 6 are attached.
A plate 2 sandwiched from above and below by a and 5b, and a connecting pin 6
Connecting plate 11 having a connecting hole 10 into which the
It consists of and.

In the above structure, the arm 8, the plate 1, the plate 3, the coil springs 5a and 5b, the connecting pin 6, the introduction hole 7, the connecting plate 11, and the connecting hole 10 are shown in FIG. Same as included.

Next, the operation will be described in detail.

In FIG. 1, the plate 1 and the plate 3 are connected by four elastic rods 4. The plate 2 is located between the plate 1 and the plate 3 and has four elastic rod holes 9 through which four elastic rods 4 pass. The plate 2 is supported by being sandwiched between the upper four coil springs 5a and the lower four coil springs 5b supported by the elastic rods 4, and the connecting pins 6 are attached thereto.

Since the diameter of the elastic rod hole 9 for passing the elastic rod 4 provided in the plate 2 is slightly larger than the diameter of the elastic rod 4, the horizontal movement of the plate 2 is restricted by the elastic rod 4. To be done. Further, the movement of the coupling pin 6 in the insertion axis direction is restricted by the expansion and contraction of the coil springs 5a and 5b.

The tip of the connecting pin 6 and the connecting hole 10 are formed in an inclined structure to facilitate the insertion, but the connecting pin 6 and the connecting plate 11 are simply inserted and the connected state is improved. Not fixed.

At the time of coupling, a positional error between the coupling pin 6 and the introduction hole 7 occurs due to an error in the control system, so that a force for moving the coupling pin 6 with respect to the plate 3 acts, but the coil spring 5a.
A restoring force that returns the connecting pin 6 to the fixed position is exerted by the restoring force of the elastic rods 4 and 5b, and consequently the plate 3 is guided to the fixed position. The restoring force in the plane perpendicular to the insertion axis can be easily analyzed from the elastic coefficient in the bending direction of the elastic rod.

FIG. 2 is an explanatory view showing the restoring force of the present invention.

As shown in FIG. 2, when the center axis 17 of the plate 2 and the center axis 16 of the plate 1 and the plate 3 deviate by a positional error of δ, the elastic rod 4 is bent as shown. Board 2
The restoring force 21 (F) acts on the plate 2 so that the central axis 17 of the plate 1 and the central axis 16 of the plate 1 and the plate 3 coincide with each other, that is, the position error δ becomes zero.

It is easy to quantitatively predict the restoring force 21 when a position error occurs, and it is calculated by the equations (1) and (2).

[0032]

[0033]

Here, F is the restoring force, E is the Young's modulus of the elastic rod, I is the second moment of area of the elastic rod, L is the length of the elastic rod, and δ is the position error.

In the coupling mechanism as described above, the positioning mechanism is important in the design, and by using the elastic rod 4 whose elastic modulus in the bending direction is known, quantitative estimation of the restoring force 21 becomes easy and the restoring force is restored. Since the force 21 is easily adjusted by the elastic coefficient in the bending direction of the elastic rod 4, the accuracy of the design procedure for detecting and correcting the position error and the ease of adjustment are excellent, and the force 21 can be coupled with high position accuracy. it can.

FIG. 3 is a partial sectional front view showing another embodiment of the coupling pin positioning mechanism of the present invention.

In FIG. 3, a hook 20 is newly provided in the structure of FIG. 1, and the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

Next, the operation will be described. When the connecting pin 6 is attached to the connecting plate 13 by the same operation as in FIG. 1, the plate 3 is fixed to the connecting plate 13 by the hook 20 mounted on the connecting plate 13 by an external driving mechanism including a spring force or a motor. As a result, a reliable bond is obtained.

[0039]

As described above, the connecting pin positioning mechanism of the present invention uses an elastic rod having a clear elastic coefficient in the bending direction to quantitatively predict the restoring force in the plane perpendicular to the insertion axis of the connecting pin. Since it is easy to analyze and adjust the restoring force, it has an effect that the connecting pin can be connected with high positional accuracy.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing an embodiment of a coupling pin positioning mechanism of the present invention.

FIG. 2 is an explanatory diagram showing the restoring force of the present invention.

FIG. 3 is a partial sectional front view showing another embodiment of the coupling pin positioning mechanism of the present invention.

FIG. 4 is a partial sectional front view showing a conventional coupling pin positioning mechanism.

FIG. 5 is an explanatory diagram showing a conventional restoring force.

[Explanation of symbols]

 1 plate 2 plate 3 plate 4 elastic rod 5 coil spring 6 coupling pin 7 introduction hole 8 arm 9 elastic rod hole 10 coupling hole 11 coupling plate 12 plate 13 coupling plate 14 rigid rod 15 central axis 16 central axis 17 central axis 19 rigid rod hole 20 hook 21 resilience

Claims (3)

[Claims] 1. A first plate connected to a control shaft for positioning, a second plate having a hole having a diameter larger than a diameter of a connecting pin passing therethrough, the first plate and the second plate. N elastic rods that connect with each other, 2n coil springs that are independently wound up and down around each of the n elastic rods, and the coupling pins are attached to allow the n elastic rods to penetrate. N coil springs wound around the upper portions of the n elastic rods and having holes of a size that fits the diameters of the elastic rods and lower portions of the n elastic rods. A third plate sandwiched between n coil springs wound in a position and a fourth plate having a coupling hole into which the coupling pin is inserted for coupling. Coupling pin positioning mechanism. 2. The coupling pin positioning mechanism according to claim 1, wherein the n elastic rods are four, and the fourth plate has n holes. 3. The coupling pin positioning mechanism according to claim 1, wherein the fourth plate has a hook for fixing the coupling between the second plate and the fourth plate.