JP2828406B2 - Automatic pressing method and device - Google Patents

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 a contacted object.

[0002]

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

[0003] The automatic pressing device includes a driving device that moves a moving object using a motor as a driving source, and a motor control device that controls the motor in accordance with a control command input from control command generating means. With the automatic pressing device,
In order to press an object (moved object) a as shown in FIG. 3A against an object (contact object) b, not only the object a is brought into contact with the object b, but also the object a 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 at the surface of the object b but at a position slightly further from the surface of the object b. .

[0004] For example, FIG.
It is assumed that the motor is driven by outputting a speed command in the speed command pattern P1 of triangular drive as shown in FIG. Then, after T1 seconds after the object a has moved by a distance proportional to the area S1,
Suppose that it reaches the surface of the object b. At the moment when the object a collides with the object b, the speed Va of the object a reverses or drops to zero according to the elasticity coefficient. However, since the speed command instructs the object a to stop further than the surface of the object b by a distance proportional to the area S2, the object a
The motor generates a torque proportional to the area S2 and presses the object a against the object b from time T1 to time T2 even after the object comes into contact with the object b and stops. Specifically, for example, when the motor to be controlled is a stepping motor, a pressing force is generated from the relationship between the angle of the positional deviation and the torque,
When the motor to be controlled is a servomotor, a current command or a torque command is generated based on the positional deviation according to each gain constituting the control block, and the object a is pressed against the object b.

[0005] Among such pressing operations, the problems are 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 the collision is too high, the speed Va of the object a is reversed according to the elasticity coefficient at the moment of the collision, and in the case of the stepping motor, there is a risk of stepping out. Object a
Even when the velocity does not reverse when the object b collides, a large impact force I is applied to the object b. Assuming that the speed of the object a does not reverse when the object a collides, that is, the speed of the object a changes to 0 during the instant (Δt), the impact force at the time of the 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, as the mass m of the object a or the speed Va at the time of the collision of the object a increases, the impact of the object a and the object b increases, and the object b is damaged, and an impact sound or vibration is generated. The only way to reduce the impact force I at the time of collision is to reduce the speed Va of the object a, considering that the mass m of the object a and the time Δt at the time of the collision are constant. Therefore, in the conventional method or apparatus, the motor is controlled using the speed command pattern P2 shown in FIG. In the speed command pattern P2, the speed at which the object a collides with the object b is reduced from Va to Vb, and then the normal inclination (usually the maximum) until just before the object a collides with the object b (time T3). After that, the inclination of the deceleration is made gentle (decrease the deceleration), and the torque required for pressing (torque proportional to the area S2) is obtained. . When the speed command pattern P2 is used, the speed at which the object a collides with the object b is reduced from Va to Vb, so that the impact force I can be reduced.

[0006]

However, when the speed command pattern P2 shown in FIG. 3 (C), which has been used in the past, is used, the object "a" is smaller than the case where the speed command pattern shown in FIG. 3 (B) is used. Although the impact force I when colliding with b can be reduced, the time required for obtaining the torque required for pressing in proportion to the area L2 (time until positioning), that is, the time from time T3 to time T4 increases. . This increase in time seems to have no effect when viewed with only one pressing operation, but as the number of pressing operations increases, this increase in time accumulates and significantly slows down the working time Results.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the impact force when a moving object collides with an abutting object and to shorten the time required for obtaining the force required for pressing (the time until positioning). An object of the present invention is to provide an automatic pressing method and apparatus that can perform the pressing.

[0008]

According to the method of the present invention, a moving object is moved by using a motor, and the moving object is brought into contact with an abutting object, and then a predetermined torque is generated by the motor. An automatic pressing method for pressing a moving object against a contact object is an object of improvement.

In the present invention, the speed of the moving object is reduced to an allowable value or less before the moving object hits the contact object. When the speed of the moving object falls below the allowable value, the moving object is accelerated and then decelerated again to generate a predetermined torque.

Here, the "permissible value" means that the speed of the moving object does not reverse when the moving object collides with the contacted object (that is, when the object is collided), It means an allowable speed that does not cause any fatal damage to any of the objects to be contacted. If the purpose is to reduce the impact sound,
In addition to the above conditions, a condition that the speed at which the impact sound falls below an allowable level is added to the “permissible value”.

The degree of "acceleration" and "deceleration again" after the moving object collides with the abutting object is determined by the performance of the motor and the control device. In order to shorten the time until the predetermined torque is generated (torque generation time), it is preferable that the acceleration at the time of acceleration and the deceleration at the time of deceleration be maximized within a range that can be obtained. When the acceleration and the 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 determined mainly by the mechanical strength of the contacted object. That is, if the torque is too large, the contacted object is damaged or broken. Therefore, the predetermined torque is arbitrarily determined according to the application.

[0012] Even if it is referred to as acceleration or deceleration, as long as the contacted object is fixed and the moved object and the contacted object are not deformed, the moved 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 apparatus according to the present invention includes a driving device for moving a moving object using a motor as a driving source, and a motor control device for controlling the motor in accordance with a control command input from control command generating means. The control command generation means presses the moving object against the contacted object, and then generates a control command such that the motor further generates a predetermined torque to press the moving object against the contacted object. Target. In the present invention, the control command generation means, the speed of the moving object is reduced to a permissible value or less until the moving object hits the contact object,
When the speed of the moving object falls below the allowable value, the moving object is accelerated and then decelerated again to output a speed command for generating a predetermined torque. The control command generated by the control command generating means may be either a speed command or a position command.

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

[0015]

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

Referring to the speed command pattern P3 in FIG. 1D, the torque generated after the collision at the time T3 (after the collision) is determined by 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 that the moving object is accelerated and then decelerated after the moving object collides with the abutting object (after time T3), a necessary area (S3 + S4), that is, a torque can be obtained in a short time. Can be.

As described above, in the present invention, the impact force is reduced by lowering the speed at which the moving object collides (collides) with the abutting object below the allowable value. By issuing the command, the torque generation time is made shorter than before.

[0018]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1A and 1B show an automatic pressing method and apparatus according to the present invention. FIG. 4 is a schematic view of an embodiment applied to pressing of a probe in an automatic in-circuit tester that automatically performs a circuit continuity test by pressing the tip of the probe. The 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 is provided with a linear guide movable part 3
Is attached. A needle support 4 is fixed to the linear guide movable portion 3, and a needle 5 constituting a needle electrode of the probe is supported on the needle support 4 so as to be movable in the vertical direction. A retaining portion 6 is fixed to an upper portion of the needle 5, and a spring retaining portion 7 is provided at an intermediate portion. A spring 8 is provided between the spring retaining portion 7 and the lower end surface of the needle support 4. It is pinched. On one surface of the motor mount 1, two pulleys 9 and 10 are rotatably arranged.
The belt 11 is hanged on. The pulley 9 is fixed to an output shaft of a motor 12 fixed to the other surface side of the motor fixing base 1, and the pulley 10 is fixed to a rotation shaft fixed to the motor mounting unit 1. The linear guide movable section 3 is attached to the belt 11, and the linear guide movable section 3 moves up and down in accordance with the movement of the belt 11.

The motor 12 is controlled by the output of a motor control device 13. The motor control device 13 is configured to control the motor according to a control command input from the control command generation means 14. In this figure, the control command generation means 14 is illustrated as being separate from the motor control device 13. However, when the motor control device 13 performs control using a CPU such as a microcomputer, the control Since the generating means 14 is realized by software or exists as data stored in a 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 external to the motor 12, and the speed and position of the linear guide movable portion 3 or the needle support are detected based on the encoder signal. The motor 12 is controlled according to the control command output from the control command generating means 14.

The control command generating means 14 outputs a speed command pattern P3 as shown in FIG. This speed command pattern P3 indicates that the motor 1
After accelerating 2, the motor is decelerated at the maximum deceleration, and then accelerated again at the maximum acceleration from time T3 when the speed reaches Vb (permissible value), and then decelerated again to become zero at time T5. Thus, the motor 12 is controlled.
Ideally, when the actual speed reaches the allowable value Vb,
It is sufficient that the tip of the needle 5 constituting a part of the moving object strikes or collides with the portion to be measured on the substrate CB, but before the tip of the needle 5 actually strikes the portion to be measured on the substrate CB or Even if the speed later becomes Vb, there is no problem if a margin is set for setting the allowable value Vb. 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 not always necessary to detect that the speed has actually reached Vb. . When acceleration and deceleration are performed at 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 the process of the operation.
The operation of this embodiment will be described with reference to FIG. First, when the motor 12 is started, the rotation of the motor 12 is converted into linear motion 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, the needle 5 moves in synchronization with the needle support 4 until the tip of the needle 5 hits the substrate CB. At time 0, the needle starts moving, 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 a further distance L2. Acceleration and re-deceleration are performed during the movement of 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 for compressing the spring 8 and pressing the needle 5 against the substrate CB.

In the present embodiment, the probing operation can be performed faster without damaging the CB substrate by suppressing the speed Vb when the needle 5 collides with the substrate CB as compared with the conventional case. Since there is a slight difference between the movements of the needle 5 and the needle support 4, 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 the present embodiment, the speed Vb at which the needle 5a hits the substrate CB can be made closer to 0, so that damage to the surface of the colliding substrate CB can be suppressed, and moreover, Fast positioning is now possible.
As a result, the relationship between the positioning time T4 in the conventional method and the positioning time T5 in the present method was T4> T5 when the collision speed was the same Vb.

As shown in FIG. 2, the present invention can be applied to driving of a mechanism for holding the object 16 by converting the rotation of the motor 12 into a linear motion using a ball screw 15. In this example,
Ball screw 1 with both ends rotatably supported on base 17
5 is rotated by the motor 12. A moving body 18 having a female screw is screwed into the ball screw 15.
8 and the end wall 17a of the base 17
Sandwich. When moving the moving body 18, FIG.
The motor 12 is driven in a pattern similar to the speed command pattern P3 shown in (D).

In this example, the speed command pattern P3 is determined so that the speed of the moving body 18 is equal to or lower 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 object 18 has hit the object 16, and the position information of the moving object 18 is obtained from the output of the encoder driven by the motor. Then, the speed of the motor may be controlled by obtaining the timing or position of the moving body 18 hitting the object 16. After the moving body 18 hits (collides with) the object 16, the moving body 18 is not actually moved, but the acceleration and re-deceleration commands are given to the motor 12 to pinch the object 16. To generate the necessary torque to
To be pinched. By doing so, the object can be sandwiched more quickly and positioning can be performed.

If 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 for detecting the distance between the moving object 18 and the position where the deceleration of the moving body 18 should be started, calculating the position where the moving object 18 comes into 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 setting can be obtained.

In each of the above embodiments, the case where the movement of the rotary type motor is converted to linear is shown, but a linear motor may be used as a drive source. The movement of the moving object (4, 5, 18) in each of the above embodiments is linear, and the operation of pressing the moving object against the contact object (CB, 16) is also linear. Is not necessarily a linear operation.

The motor used in each of the above embodiments is preferably a position controllable motor such as a stepping motor or a servomotor.

In each of the above embodiments, the control command generating means 14
Speed command is used as the control command output from
Of course, a position command may be output as a 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 set to ± 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 contacting object (CB, 16) by this continuous operation, FIG.
Speed command can be given.

[0032]

According to the present invention, the impact force can be reduced because the speed at which the moving object collides with the abutting object is equal to or less than the allowable value. In addition, after the moving object collides with the abutting object, a predetermined torque can be generated in a short time by instructing the motor to accelerate and re-decelerate, so that the force required for pressing can be obtained. There is an advantage that the time required for the above (time until positioning) can be made shorter than before.

[Brief description of the drawings]

FIGS. 1A and 1B show an automatic pressing method and apparatus according to the present invention, in which a probe of a measuring probe is attached to a portion to be measured (a measuring electrode or a soldered portion) of a circuit board on which electronic components are mounted. FIG. 3C is a schematic front view and a side view of an example applied to the pressing of a probe in an automatic in-circuit tester that automatically performs a continuity test of a circuit by pressing the tip of the electrode, and FIG.
FIG. 4 is a diagram illustrating a process of an operation, and FIG.

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

3A is a diagram used to explain a conventional automatic pressing method, and FIGS. 3B and 3C show examples of speed command patterns used in a conventional automatic pressing device, respectively. FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 motor mount 2 linear guide fixing part 3 linear guide movable 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

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-51836 (JP, A) JP-A-63-174780 (JP, A) JP-A-5-243795 (JP, A) JP-A-2- 224300 (JP, A) JP-A-2-256299 (JP, A) JP-A-5-104349 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 13/00

Claims (3)

(57) [Claims] An object is moved by using a motor, the object is brought into contact with an object to be contacted, and then a predetermined torque is generated by the motor to apply the object to the object. An automatic pressing method for pressing against an object, wherein the speed of the object is reduced to an allowable value or less until the object hits the object, and the speed of the object is reduced to the allowable value. An automatic pressing method, wherein the moving object is pressed against the abutted portion by controlling the motor so that the motor is accelerated and then decelerated again to generate the predetermined torque when the value falls below the value. A driving device for moving the moving object by using the motor as a driving source; and a motor control device for controlling the motor in accordance with a control command input from control command generating means, wherein the control command generation is performed. Means for automatically pushing the motor to generate a control command to press the moving object against the contacted object by causing the motor to generate a predetermined torque after hitting the object to be contacted. An abutment device, wherein the control command generating means reduces the speed of the moving object to a permissible value or less before the moving object hits the abutting object, and the speed of the moving object is equal to or less than the permissible value. An automatic pressing device for outputting a speed command for decelerating again when the value becomes equal to or less than the value and decelerating again to generate the predetermined torque. 3. A moving object is moved by using a motor as a driving source.
Drive device and a control finger input from the control command generation means.
A motor control device for controlling the motor in accordance with a command.
The control command generating means is configured to transfer the moving object to an abutting object.
And then generate a predetermined torque to the motor.
And press the moving object against the abutting object.
An automatic pressing device that generates a control command , wherein the control command generation means is configured to determine that the moving object is the contacted object.
Keep the speed of the moving object below the allowable value before hitting
Decelerates and the speed of the moving object falls below the allowable value
After accelerating, decelerate again to generate the predetermined torque.
An automatic pressing device for outputting a position command .