JPH0897590A - Method and device for automatically pressing object against another object - Google Patents

Abstract

PURPOSE: To reduce the impact force when an object to be moved is brought into contact with an object to be contacted and, at the same time, to shorten the time required to obtain a force required for pressing the object to be moved against the object to be contacted (to position the object to be moved). CONSTITUTION: After a needle 5 (object to be moved) is brought into contact with a substrate CB (object to be contacted) by moving the needle 5 together with a needle holder 4 by means of a motor 12, the needle 5 is pressed against the substrate CB by further causing the motor 12 to generate a prescribed torque. A control command generating means 14 gives a speed command to a motor controller 13 to reduce the speed of the needle 5 to an allowable value Vb or lower until the needle 5 comes into contact with the substrate CB. When the speed of the needle 5 becomes equal to or lower than the allowable value Vb, the means 14 gives another speed command to again reduce the speed of the needle 5 after the speed is increased. Therefore, the motor 12 can generate the torque required to press the needle 5 against the substrate CB in a short time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic pressing method and apparatus for automatically pressing a moving object against an abutting object.

[0002]

2. Description of the Related Art An automatic test for automatically conducting a circuit continuity test by pressing the tip of a needle electrode of a measuring probe against a portion to be measured (a measuring electrode or a soldering portion) of a circuit board on which electronic parts are mounted. BACKGROUND ART Automatic pressing technology is adopted for pressing a probe in a circuit tester and pressing a robot hand against an object in a robot handling operation.

The automatic pressing device comprises a drive device for moving a moving object using a motor as a drive source, and a motor control device for controlling the motor according to a control command input from a control command generating means. With the automatic pressing device,
In order to press the object (moving object) a as shown in FIG. 3 (A) against the object (contacting object) b, not only the object a is brought into contact with the object b, but also the object a is brought into contact with the object b. Even after contact
It is necessary to generate a predetermined torque in the motor and press the object a against the object b. Therefore, the control command input from the control command generation means to the motor control device sets the stop target position of the object a not to the surface of the object b but to a position slightly further back from the surface of the object b. .

For example, referring to FIG.
It is assumed that the motor is driven by outputting the speed command with the triangular drive speed command pattern P1 as shown in FIG. Then, the object a moves T1 seconds after moving by a distance proportional to the area S1,
It is assumed that the surface of the object b is reached. At the moment when the object a collides with the object b, the velocity Va of the object a is reversed or drops to zero velocity according to the elastic coefficient. However, since the speed command commands the object a to stop further by a distance proportional to the area S2 than the surface of the object b, the object a
Even after the object comes into contact with the object b and stands still, the motor generates a torque proportional to the area S2 and presses the object a against the object b between times T1 and T2. Specifically, for example, when the controlled motor is a stepping motor, a pressing force is generated due to the relationship between the positional deviation angle and the torque,
When the motor to be controlled is a servo motor, a current command or a torque command is generated based on the positional deviation according to each gain forming the control block, and the object a is pressed against the object b.

A problem in such a pressing operation is the magnitude of the impact when the object a collides with the object b and the time until a predetermined torque is generated after the collision. If the speed at the time of collision is too high, the speed Va of the object a is reversed according to the elastic coefficient at the moment of collision, and in the case of a stepping motor, there is a risk of step out. Object a
Even if the velocity does not reverse when the vehicle collides, a large impact force I is applied to the object b. When the speed of the object a does not reverse when it collides, that is, the speed of the object a changes to 0 in an instant (Δt), the impact force at the time of collision when the mass of the object a is m. I is represented by I = {m (Va-0) / Δt} = {m · Va / Δt} (1). That is, the greater the mass m of the object a or the velocity Va at the time of collision of the object a, the greater the impact of the object a and the object b, and the object b is damaged or the impact sound or vibration is generated. In order to reduce the impact force I at the time of a collision, considering that the mass m of the object a and the time Δt at the time of the collision are constant, there is no choice but to reduce the speed Va of the object a. Therefore, in the conventional method or apparatus, the motor is controlled using the speed command pattern P2 shown in FIG. In this speed command pattern P2, the speed at which the object a collides with the object b is lowered from Va to Vb, and then the normal inclination (usually the maximum is reached) immediately before the object a collides with the object b (time T3). Deceleration at the limit), and after that (after time T3), the gradient of deceleration is made gentle (decrease in deceleration) to obtain the torque required for pressing (the torque proportional to the area S2). . By using this speed command pattern P2, the speed at which the object a collides with the object b is reduced from Va to Vb, so the impact force I can be reduced.

[0006]

However, when the speed command pattern P2 of FIG. 3 (C), which has been used conventionally, is used, the object a becomes an object compared to the case of using the speed command pattern of FIG. 3 (B). Although the impact force I at the time of collision with b can be reduced, the time required to obtain the torque required for pressing in proportion to the area L2 (time until positioning), that is, the time from time T3 to time T4 is extended. . This time extension seems to have no effect when viewed with only one pressing operation, but when the number of pressing operations increases, this time extension accumulates and the working time is significantly delayed. Result.

An object of the present invention is to reduce the impact force when a moving object collides with an abutting object, and to shorten the time (time until positioning) required to obtain the force necessary for pressing. An object of the present invention is to provide an automatic pressing method and device capable of performing.

[0008]

According to the method of the present invention, a moving object is moved using a motor, the moving object is abutted against the abutting object, and then a predetermined torque is further generated in the motor. An automatic pressing method for pressing a moving object against an abutting object is targeted for improvement.

In the present invention, the speed of the moving object is reduced to the allowable value or less before the moving object hits the abutting object. When the speed of the moving object becomes equal to or lower than the allowable value, the moving object is accelerated and then decelerated again to generate a predetermined torque.

Here, the "permissible value" means that the velocity of the moving object does not reverse when the moving object hits the contacting object (that is, when the moving object collides), and the moving object and It means an allowable speed that does not cause fatal damage to any of the contacted objects. If you want to reduce the impact noise,
In addition to the above conditions, this "permissible value" is accompanied by a condition that the speed at which the impact sound falls below an acceptable level.

The degree of "acceleration" and "deceleration again" after the moving object hits the contacting object is determined by the performance of the motor and the control device. In order to reduce the time until the predetermined torque is generated (torque generation time), it is preferable that the acceleration during acceleration and the deceleration during deceleration be maximized within the range that can be obtained. When the acceleration and deceleration and the magnitude of the generated torque are determined, the acceleration time and the deceleration time are naturally determined. The "predetermined torque" to be obtained is mainly determined by the mechanical strength of the contacted object. That is, if this torque becomes too large, the contacted object is damaged or broken. Therefore, this predetermined torque is arbitrarily determined according to the application.

Even if acceleration or deceleration is performed, if the abutting object is fixed and the moving object and the abutting object do not deform, the moving object does not move,
The motor is accelerating and decelerating (in practice, the current value or voltage value supplied to the motor is changing).

The device of the present invention comprises a drive device for moving a moving object using a motor as a drive source, and a motor control device for controlling the motor according to a control command input from a control command generation means, The control command generation means, after abutting the moving object against the abutting object, further generates a control torque for the motor to generate a control command for pressing the moving object against the abutting object. Target. In the present invention, the control command generating means, the speed of the moving object is reduced to the allowable value or less by the time the moving object hits the contacted object,
When the speed of the moving object becomes equal to or lower than the allowable value, the speed is accelerated and then decelerated again to output a speed command for generating a predetermined torque. The control command generated by the control command generation means may be either a speed command or a position command.

The control command generating means may be constituted by hardware, but when the motor control device has a built-in computer and is program-controlled, the control command generating means may be constituted by software. .

[0015]

In the prior art, it has been common knowledge for those skilled in the art that after deceleration is started, a predetermined torque is obtained by changing the degree of deceleration (deceleration) without accelerating. This is a common sense derived from the response speed or response performance of conventional motors and control devices. However, recent technological advances have dramatically improved the response speed or response performance of motors and control devices. The inventor has paid attention to the improvement in response speed or response performance of the motor and the control device, and has come to adopt an idea that breaks the conventional common sense, that is, an idea of accelerating after starting deceleration.

Looking at the speed command pattern P3 in FIG. 1D, the torque generated after the collision at time T3 (after the collision) is the area (S3 + S4) of the region surrounded by the speed command pattern P3 and the time axis. ). Therefore, if the motor is controlled so as to accelerate and then decelerate the moving object after the moving object collides with the abutting object (after time T3), the required area (S3 + S4), that is, torque can be obtained in a short time. You can

As described above, in the present invention, the impact force is reduced by setting the speed at which the moving object strikes (collides with) the contacted object to be less than the allowable value, but thereafter, acceleration and re-deceleration are performed by the motor. By issuing a command, the torque generation time is made shorter than before.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 (A) and 1 (B) show the automatic pressing method and device of the present invention, in which the needle-shaped electrode of the measurement probe is attached to the measured portion (measurement electrode or soldering portion) of the circuit board on which electronic components are mounted. FIG. 6 is a schematic diagram of an example applied to pressing a probe in an automatic in-circuit tester that automatically performs a circuit continuity test by pressing the tip of the probe. This automatic in-circuit tester includes a linear guide fixing portion 2 on one surface of a motor mount 1. The linear guide fixed part 2 has a linear guide movable part 3 slidable in the vertical direction.
Is attached. A needle support 4 is fixed to the linear guide movable portion 3, and a needle 5 that constitutes a needle electrode of a probe is supported on the needle support 4 so as to be vertically movable. A retaining portion 6 is fixed to an upper portion of the needle 5, and a spring locking portion 7 is provided in an intermediate portion. A spring 8 is provided between the spring locking portion 7 and a lower end surface of the needle support 4. It is pinched. Two pulleys 9 and 10 are rotatably arranged on one surface of the motor mount 1. These pulleys 9 and 10 are
A belt 11 is hung on the. The pulley 9 is fixed to the output shaft of the motor 12 fixed to the other surface side of the motor fixing base 1, and the pulley 10 is fixed to the rotating shaft fixed to the motor mounting portion 1. The linear guide movable portion 3 is attached to the belt 11, and the linear guide movable portion 3 moves up and down according to the movement of the belt 11.

The motor 12 is controlled by the output of the motor controller 13. The motor control device 13 is configured to control the motor according to the control command input from the control command generation means 14. In this figure, the control command generating means 14 is illustrated as being separate from the motor control device 13, but when the motor control device 13 controls using a CPU such as a microcomputer, this control command is generated. Since the generating means 14 is realized by software or exists as data stored in the memory, the control command generating means 14 does not exist in a visible state. An encoder signal is input to the motor control device 13 from an encoder built in or attached to the motor 12, and the speed and position of the linear guide movable part 3 or the needle support is detected based on the encoder signal, and the detection result is detected. The motor 12 is controlled according to the control command output from the control command generator 14.

The control command generating means 14 outputs a speed command pattern P3 as shown in FIG. 1 (D). This speed command pattern P3 is applied to the motor 1 with the maximum acceleration from time 0.
After accelerating 2, the motor is decelerated with the maximum deceleration, and from time T3 when the speed reaches Vb (allowable value), the motor is accelerated again with the maximum acceleration, and then decelerated again, and the speed becomes 0 at time T5. Is configured to control the motor 12.
Ideally, when the actual speed reaches the allowable value Vb,
It suffices that the tip of the needle 5 forming a part of the object to be moved hits or collides with the portion to be measured on the substrate CB, but before the tip of the needle 5 actually hits the portion to be measured on the substrate CB or Even if the speed becomes Vb later, if there is a margin in setting the allowable value Vb, there will be no problem. Therefore, whether or not the speed has reached Vb may be determined from the operation time or from the position obtained from the output of the encoder, and it is necessary to detect that the speed has actually reached Vb. . When acceleration and deceleration are executed with the maximum acceleration and deceleration as in this embodiment, the operation time including the torque generation time can be minimized.

FIG. 1C is a diagram showing a process of operation.
The operation of this embodiment will be described with reference to this figure. When first activated, the rotation of the motor 12 is converted into a linear movement via the belt 11, and the needle support 4 moves toward the substrate CB. Since the needle 5 is connected to the needle support 4 via a spring, it moves in synchronization with the needle support 4 until the tip of the needle 5 hits the substrate CB. The needle starts moving at time 0, and after moving the distance L1, the tip of the needle 5 reaches the surface of the substrate CB, and the needle 5 stops at that position. However, the needle support 4 moves further by the distance L2. Acceleration and re-deceleration are executed while moving the distance L2. That is, during this distance L2, a force (torque) proportional to the spring coefficient of the spring 8 and the distance L2 is generated as a force that compresses the spring 8 and presses the needle 5 against the substrate CB.

In the present embodiment, the speed Vb when the needle 5 collides with the substrate CB is kept lower than in the conventional case, so that the probing operation can be performed faster without damaging the CB substrate. Since the movements of the needle 5 and the needle support 4 are slightly different, it is preferable to control the speed of the needle support 4 early even before the needle 5 actually hits the substrate CB.

When the pressing operation is completed, the control command generating means 14 outputs a control command for separating the needle 5 from the substrate CB to the motor control device 13, and one operation is completed.

According to this embodiment, the speed Vb at which the needle 5a hits the substrate CB can be made closer to 0, and the surface damage of the substrate CB that collides can be suppressed, and moreover, Fast positioning is now possible.
As a result, the relationship between the positioning time T4 required in the conventional method and the positioning time T5 in this method was T4> T5 when the speed at the time of collision was the same Vb.

The present invention can also be applied to the driving of a mechanism for pinching the object 16 by converting the rotation of the motor 12 into a linear movement using a ball screw 15, as shown in FIG. In this example,
Ball screw 1 whose both ends are rotatably supported by the base 17
5 is rotated by the motor 12. A moving body 18 formed with a female screw is screwed into the ball screw 15, and the moving body 1
8 and the end wall 17a of the base 17 between the object 16
Sandwich. When the moving body 18 is moved, as shown in FIG.
The motor 12 is driven in the same pattern as the speed command pattern P3 shown in (D).

In this example, the speed command pattern P3 is set so that the speed of the moving body 18 is equal to or less than the allowable value Vb before the moving body 18 hits (collides with) the object 16. If the size of the object 16 is known in advance, it is not necessary to actually detect whether or not the moving body 18 hits the object 16, and the position information of the moving body 18 is output from the output of the encoder driven by the motor. Then, the speed control of the motor may be performed by obtaining the time or position where the moving body 18 hits the object 16. Then, after the moving body 18 hits (collides with) the object 16, the moving body 18 is not actually moved, but the motor 12 is commanded to accelerate and re-decelerate to hold the object 16. The torque required to generate 16
To pinch. By doing so, the object can be sandwiched and positioned more quickly.

When the size of the object 16 is unknown, a sensor for detecting the end of the object 16 or the object 16 and the moving body 18
By providing a sensor that detects the distance between the moving body 18 and the position where the deceleration of the moving body 18 should be started, calculating the position in contact with the surface of the object 16 and controlling the motor 12, the position information can be obtained in advance. The same effect as when it can be set is obtained.

In each of the above-described embodiments, the movement of the rotary type motor is converted into linear, but a linear motor may be used as a drive source. In addition, the movements of the moving objects (4, 5, 18) in each of the above-described embodiments are linear, and the operation of pressing the moving object against the contacted objects (CB, 16) is also linear. The movement of does not necessarily have to be a linear movement.

The motor used in each of the above embodiments is preferably a motor whose position can be controlled, such as a stepping motor or a servo motor.

In each of the above embodiments, the control command generating means 14
The speed command is used as the control command output from
Of course, a position command may be output as the control command.

As an example of realizing the speed command pattern of FIG. 1D, a movement command corresponding to (S1 + S3) in FIG. 1D is given and the in-position width is ± S3.
Set to. Then, after confirming that the moving object has arrived within the in-position width, S4 may be added to the movement command. Here, (S3 + S4) = S2. While confirming that the moving object (4,5, 18) approaches the contacted object (CB, 16) by this continuous operation, FIG.
The speed command of can be given.

[0032]

According to the present invention, since the speed at which the moving object strikes the contacted object is set to the allowable value or less, the impact force can be reduced. In addition, by instructing the motor to accelerate and re-decelerate after the moving object hits the contacted object, a predetermined torque can be generated in a short time, so that the force required for pressing can be obtained. There is an advantage that the time required for (positioning time) can be shortened compared to the conventional case.

[Brief description of drawings]

1 (A) and 1 (B) show an automatic pressing method and device of the present invention, in which a probe of a measuring probe is attached to a portion to be measured (a measuring electrode or a soldering portion) of a circuit board on which an electronic component is mounted. FIG. 14C is a schematic front view and a side view of an example applied to pressing a probe in an automatic in-circuit tester that automatically conducts a circuit continuity test by pressing the tip of the electrode.
FIG. 6A is a diagram showing a process of operation, and FIG. 7D is a diagram showing an example of a speed command pattern.

FIG. 2 is a schematic view of another embodiment to which the present invention can be applied.

FIG. 3A is a diagram used for explaining a conventional automatic pressing method, and FIGS. 3B and 3C show examples of speed command patterns used in the conventional automatic pressing device. It is a figure.

[Explanation of symbols]

 1 Motor Mounting Base 2 Linear Guide Fixed Part 3 Linear Guide Moving Part 4 Needle Support 5 Needle 6 Retaining Part 7 Spring Locking Part 8 Spring 9, 10 Pulley 11 Belt 12 Motor 13 Motor Control Device 14 Control Command Generation Means

Claims (3)

[Claims] 1. A moving object is moved by using a motor, the moving object is abutted against an abutting object, and a predetermined torque is further generated in the motor to hit the moving object. An automatic pressing method of pressing against a contact object, wherein the speed of the transferred object is reduced to an allowable value or less until the transferred object hits the contacted object, and the speed of the moved object is the allowable value. An automatic pressing method characterized by accelerating and then decelerating again when the value is less than a value to control the motor so as to generate the predetermined torque to press the moving object against the contacted portion. 2. A drive device for moving an object to be moved using a motor as a drive source, and a motor control device for controlling the motor according to a control command input from a control command generation means. The means automatically pushes the moving object against the abutting object, and then generates a control command to further generate a predetermined torque in the motor to press the moving object against the abutting object. In the hitting device, the control command generation means reduces the speed of the moving object to an allowable value or less by the time the moving object hits the abutting object, and the speed of the moving object is the allowable value. An automatic pressing device which outputs a speed command for accelerating and then decelerating again to generate the predetermined torque when the value is less than a value. 3. The automatic pressing device according to claim 2, wherein the control command generating means outputs a speed command or a position command as the control command.