JP2001062765A - Method and device for automatic pressing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost of an entire device by obtaining positional information and speed information on a rotor from a detection device such as a hole element built in a motor to drive the motor. SOLUTION: This device 10 comprises a control command device 11 a drive device 13 moving a movable member 1 by a motor M and a control device 12 for controlling the motor M by an instruction from the control command device 11 and presses the movable member 1 against a contacted member 2. A contact between the movable member 1 and the contacted member 2 is performed by the detection of a variation in current flowing to a motor winding and a rotor position detector 14. The control device 12 drives the movable member 1 by the drive device 13 according to an instruction from the control command device 11 and reduces the speed of the movable member 1 and a torque of the motor M to allowable values until the member touches the contacted member 2 and after the movable member 1 touches the contacted member 2, controls the motor M so that the motor can generate an increased torque in order to press the movable member 1 against the contacted member 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an automatic pressing method and an automatic pressing method.

[0002]

2. Description of the Related Art Conventionally, as an automatic pressing method and apparatus of this kind, for example, a measuring portion of a printed circuit board (or a printed circuit board) on which electronic parts such as semiconductors are assembled, for example, a measuring terminal or a soldering portion The probe is pressed against an automatic inspection machine that automatically tests the continuity and characteristics of necessary circuits by pressing against the tip of a needle-shaped measurement probe, and holding a workpiece of an automated machine. And the pressing of the robot hand for gripping a workpiece in the handling operation of the robot hand.

[0003] The automatic pressing device comprises means for instructing control, driving means for moving a movable member by driving a motor, and control means for controlling the motor in accordance with a command from the control command means. I have. According to the automatic pressing device, the movable member 1 as shown in FIG.
Is pressed against the member to be contacted 2, even after the movable member 1 contacts the member to be contacted 2, the motor is further increased, that is, a larger torque is generated by the motor. Therefore, it is necessary to press the movable member 1 against the contacted member 2. Therefore, the control command input from the control command means to the control means usually sets the stop target position of the movable member 1 from the contact surface of the contacted member 2.
The position is set a little further into the back.

[0004] In this case, the control command means issues a signal shown in FIG.
When a speed command according to the triangular speed command pattern P1 shown in (b) is output and the motor of the driving means is driven, the moving distance of the movable member 1 moves at the speed Va, and after the time T1, the area S1 And reaches the contact surface of the contacted member 2. However, since the speed command instructs the movable member 1 to stop at a position deeper than the contact surface of the contacted member 2 by a distance corresponding to the area S2, the moving member 1 The motor generates a torque proportional to the area S2 from time T1 to time T2 even after stopping after contacting the contacted member 2, and pushing the moving member 1 against the contacted member 2. Hit it. Specifically, when the motor is a stepping motor, a pressing force is generated from the relationship between the angle of the positional deviation and the torque, and when the motor is a servo motor, the pressing force is generated according to each gain constituting a control block. Then, a current command or a torque command is generated based on the displacement, and the movable member 1 is pressed against the contacted member 2.

The problem in this operation is the magnitude of the impact when the movable member 1 collides with the abutted member 2 and the time until the motor generates a predetermined torque after the collision. If the speed at the time of the collision is too high, the speed Va of the movable member 1 is reversed at the moment of the collision according to the elasticity coefficient, and in the case of a stepping motor, the motor may lose synchronism. Movable member 1
When the vehicle collides with the abutted member 2, even if the speed does not reverse, it is assumed that the movable member 1 stops for a short time (Δt), that is, if the speed of the movable member 1 changes to zero, the movable member 1 The impact force I of the collision when the mass of m is m is represented by I = {m (Va-0) / {t} = {mVa / {t}.

At this time, in order to reduce the impact force I of the collision, the mass m of the movable member 1 and the short time Δt at the time of the collision are required.
Is constant, there is no other choice but to decrease the speed Va of the movable member 1. Therefore, in the conventional method or apparatus, FIG.
The motor is controlled by the speed command pattern P2 shown in FIG. In this speed command pattern P2, when the movable member 1 collides with the contacted member 2, the speed is reduced from Va to Vb, and immediately before the movable member 1 collides with the contacted member 2 (time Until T3), the vehicle decelerates at the normal maximum deceleration, and thereafter (after the time T3),
The motor decelerates at a gentle deceleration to obtain a torque necessary for pressing and proportional to the area S2 shown in FIG. According to the speed command pattern P2, the impact force I can be made as small as possible.

On the other hand, as an object gripping device 4 shown in FIG. 7, there is a mechanism for converting the rotation of a motor M into a linear motion via a ball screw 5 to grip an object 6. That is, the ball screw 5 whose both ends are rotatably supported on the base 7
A movable body 8 having a female screw threaded therein is screwed therein. By rotating the motor M, the end of the movable body 8 and the base 7 are rotated.
The object 6 is sandwiched between the fixed end portion 7a and the fixed end portion 7a. When the movable body 8 is moved, the motor M is controlled and driven by a speed command pattern P3 as shown in FIG.

By the time the movable body 8 contacts (collides with) the object 6, the speed of the movable body 8 is reduced to an allowable value Vb.
It is determined to be as follows. When the size of the object 6 is known in advance, it is not necessary to detect the contact of the movable body 8 with the object 6, and the position information of the movable body 8 is stored in an encoder connected to the motor M. , The speed or the position of the movable body 8 in contact with the object 6 is determined to control the speed of the motor M. After the movable body 8 abuts (collides) with the object 6, the movable body 8 is not actually moved, and acceleration and deceleration commands are given to the motor M.
A torque necessary for holding the object 6 is generated, and the object 6 is supported. (Japanese Patent No. 2828406)

[0009]

However, in such a conventional automatic pressing method and its apparatus, since an expensive servomotor is usually used, the cost of the entire apparatus is increased. . Also, usually
Since a servomotor is used, there is a problem that setting such as position control, speed control, and torque control corresponding to a member to be pressed in advance is required, and complicated control is required. .

[0010] The present invention has been made in view of such a point,
The purpose is to solve the above problems, such as the automatic inspection machine for testing the continuity and characteristics of the circuit of the printed circuit board,
It is not an application that requires pressing at high speed. For example, a brushless motor can be used as a motor without using an encoder. An automatic pressing method and an automatic pressing method that can reduce the cost of the entire apparatus by obtaining position information and speed information of the rotor from a detection element such as a Hall element incorporated in the motor and driving the motor. To provide.

Another object of the present invention is to provide an automatic pressing device used as a device for gripping a work (or an object) in, for example, positioning of an automated machine or handling operation of a robot hand.

[0012]

The structure of the present invention for achieving the above object is as follows. An automatic pressing method of driving a motor to move a movable member, bringing the movable member into contact with a member to be contacted, and further increasing the motor to press the movable member against the member to be contacted. In, until the movable member contacts the contacted member,
The speed of the movable member and the torque of the motor are set to be equal to or less than a permissible value. Then, the motor is controlled so as to generate a predetermined torque increased by the motor, and the movable member is pressed against the contacted member.

[0013] Also, the control means includes means for instructing control, driving means for moving the movable member by driving a motor, and control means for controlling the motor in accordance with a command from the control command means. The automatic pressing device for pressing against the contacted member further includes a unit for detecting that the moving member comes into contact with the contacted object, and the control unit responds to a command from the control command unit. By moving the movable member in the direction of the contacted member by the driving means, until the movable member comes into contact with the contacted member, the speed of the movable member and the torque of the motor should be equal to or less than an allowable value, The contact of the moving member with the contacted object is detected by the contact detection unit, and thereafter,
An automatic pressing device that controls the motor so as to generate a predetermined torque increased by the motor and presses the movable member against the contacted member.

Further, the motor is a brushless motor, and the means for detecting that the moving member comes into contact with the object to be contacted is an automatic pressing device comprising a plurality of Hall elements built in the brushless motor. It is.

Further, the movable member and the contacted member may be a gripping mechanism including a pair of opening and closing members. After the object is gripped between the opening and closing members, the torque of the motor is increased to open and close the opening and closing members. An automatic pressing device for controlling the motor so as to generate a predetermined gripping force between members.

In the present invention, the speed of the movable member when the movable member comes into contact with the contacted member is set to be equal to or less than an allowable value. Then, after the movable member comes into contact with the abutted member, the motor generates the increased torque. Here, the allowable value means that when the movable member comes into contact with the contacted member (at the time of collision), the speed of the movable member does not reverse, and both the movable member and the contacted member are not rotated. Means the speed at which no damage occurs. When it is required to reduce the contact sound (or the impact sound), in addition to the above, a condition is added to the above-described allowable value such that the speed at which the contact sound is reduced to an acceptable level or less. Also,
After the movable member comes into contact with the contacted member, the increased predetermined torque to be generated by the motor is determined mainly by the mechanical strength of the contacted member. Therefore, the predetermined torque is arbitrarily determined according to the application.

Since the present invention is configured as described above, for example, a brushless motor can be used as the motor.
Without using an encoder. By obtaining the position information and speed information of the rotor using a Hall element or the like built in the motor and driving the rotor, the entire device can be manufactured at low cost. Then, the size of the member to be pressed, that is, the size of the movable member, or the size of the object to be gripped is detected by a change in the motor current or (and / or) a change in the speed of the rotor when pressed. Different types of objects can be pressed and gripped. Further, by performing control so as to gradually increase the pressing force or the gripping force after the pressing, deformation and distortion to the object to be pressed are reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the automatic pressing device according to the present invention, which also shows an apparatus for performing the automatic pressing method.
FIGS. 2A and 2B are diagrams for explaining the function of the contact detector in FIG. 1, and show the relationship between the drive current of the motor and the time before and after the movable member contacts the contact member. FIG. 3 is a configuration circuit diagram of a embodied automatic pressing device.

In FIG. 1, this automatic pressing device 10
Is a control command device 11 for commanding control, a control device 12 for controlling and driving the motor M by a command signal output from the control command device 11, and a drive mechanism for moving the movable member 1 by driving the motor M Drive device 1 provided with
3 and a contact detector 14 for detecting the contact of the movable member 1 with the contact member 2.

The control command device 11 may be constituted by known hardware. However, when the control device 12 for controlling the motor M is controlled by a program containing a computer, the control command The device 11 can also be constituted by software. The contact detector 14 detects when the movable member 1 contacts the contacted member 2 and the contact position, and the two members 1 and 2 contact each other, as shown in FIG. As shown, when the rotor of the motor M stops, the time T0 at which the drive current to the motor M sharply increases is detected, or a plurality of, for example, three As shown in FIG. 2 (b), the stop of the rotor, that is, the time T0 when the speed of the rotor becomes zero and the position thereof are detected by the Hall element and the permanent magnet formed on the rotor. , And sends the output signal to the controller 12.

In the automatic pressing device 10, the control device 12 drives the motor M according to a command signal output from the control command device 11, and drives the motor M via the drive device 13. The movable member 1 is moved in the direction of the contacted member 2. After the movement is started, the movable member 1 is moved until the movable member 1 comes into contact with the contacted member 2.
While the speed of the motor M and the torque of the motor M are set to be equal to or less than the allowable value, the movable member 1
When the contact signal is detected by the contact detector 14 and the detection signal is output to the control device 8, the control device 8 causes the motor M to generate a predetermined increased torque, The motor M is controlled so that is pressed against the contacted member 2.

FIG. 3 is a circuit diagram of a specific embodiment of the automatic pressing apparatus according to the present embodiment. The same members as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. The automatic pressing device 20 includes a control command device 1 for commanding control.
1, a control device 22 for controlling and driving a motor M by a command signal output from the control command device 11, a driving device 13 having a driving mechanism for moving the movable member 1 by driving the motor M, The movable member 1 is a contact member 2
And a contact detector 14 for detecting contact with the contact.

In FIG. 3, a brushless motor M1 as the motor M and three Hall elements HE1, HE2, HE2, which are built in the brushless motor M1 as the contact detector 14, and detect the position of the rotor thereof. HE3, and the detection signals output from the Hall elements HE1, HE2, HE3 are input to the control device 22. Although the brushless motor M1 is shown as a three-phase four-pole brushless motor, it is not necessarily limited thereto.
A brushless motor having three phases, ten poles, three phase, and 12 poles may be used.

In the control device 22, when a control command signal output from the control command device 11 is input to an excitation sequence control circuit 22a, the control command signal follows the excitation sequence of the brushless motor M1 generated by the excitation sequence control circuit 22a. The brushless motor M1 of the load is driven by the motor drive circuit 22d based on the power supplied from the power supply circuit 22b and the PWM-controlled constant current output from the current control circuit 22c. That is, the motor drive circuit 22d excites the excitation winding of the motor M1 according to the predetermined excitation sequence, and drives the motor M1. The magnitude of the drive current flowing through the motor M1 is detected by a current detection resistor R, and based on this detection signal,
The current control circuit 22c controls so that a constant current flows to the drive circuit 22d.

The contact detector 14 is provided with Hall elements HE1, HE2, and H2 for detecting the position of the rotor of the brushless motor M1.
E3 is provided to detect the rotor speed of the motor M1 and send the speed signal to the excitation sequence control circuit 22a of the control device 22. The speed signal is converted into a pulse signal for speed feedback by an excitation sequence control circuit 22a, and further converted into a voltage signal for speed feedback by an F / V (frequency / voltage) converter 22e.

The speed feedback voltage signal is compared with a speed setting voltage signal set by a speed setting unit 22f by an error amplifier 22g, and the speed deviation signal is output to the current control circuit 22c. The current control circuit 22c changes the pulse width of the PWM control in accordance with the speed deviation signal and outputs the PWM control to the drive circuit 22d to control the rotation speed of the brushless motor M1. Therefore, the speed of the motor M1 is controlled and driven by the speed setting of the speed setting unit 22f so that the speed of the motor M1 becomes a predetermined value. In this case, the speed setting of the speed setting unit 22f is automatically set by the control device 22 by a program having a built-in computer.

The automatic pressing device 20 of this embodiment is similar to that of FIG.
As shown in FIG. 2, when the movable member 1 comes into contact with (or collides with) the contacted member 2 in order to press the movable member 1 against the contacted member 2, the control device 22 The movable member 1 is moved by setting a speed Vb at which the contacted member 2 is not damaged or vibration is not generated. As shown in FIG. 2 (a), when the movable member 1 collides with the abutted member 2 at a speed Vb, the rotation of the motor M1 also stops instantaneously. When the electromotive voltage becomes zero, the drive current flowing through the motor M1 increases. By detecting this change in current and confirming that there is no change in the output signals from the Hall elements HE1, HE2, and HE3 within a certain time, the contact between the movable member 1 and the contacted member 2 is determined. To detect.

Thereafter, the torque generated by the motor M1 is increased so as to obtain a predetermined pressing force, and the movable member 1 can be pressed against the contacted member 2 with a large force. When the abutted member 2 is formed of a soft material, the pressing force after the abutting (or collision) is gradually increased over a certain period of time, thereby deforming the abutted member 2. And distortion can be reduced.

Next, FIGS. 4 and 5 are a front view and a right side view of an example of the gripping device 23 used in the driving device 13 of FIG. 3 of the present embodiment. 4 and 5, the gripping device 23 performs gear cutting on the output shaft 23a of the brushless motor M1, meshes with the cut output shaft 23a, and positions the racks 31, 3 at symmetrical positions.
1 are provided respectively. Guide rails 32, 32 are respectively disposed on the motor flange 23b, and the racks 31, 3 are respectively mounted on guide blocks 33, 33 which are disposed to slide on the guide rails 32, 32.
1 is fixed by a screw. The racks 31, 31
Are fixed to each other, and when the output shaft 23a of the motor M1 rotates in the CW direction, the claws 34a and 34b move in a direction in which the claws 34a and 34b come into contact with each other. The work (not shown) is gripped.

The technique of the present invention is not limited to the technique in the above-described embodiment, but may be implemented by means of other modes that perform the same function. Can be changed or added.

[0031]

As is apparent from the above description, according to the automatic pressing method and the apparatus of the present invention, the configuration is as described in the first and second aspects.
By obtaining the position information and speed information of the rotor from the detection element built in the motor, by driving the motor,
There is an effect that the cost of the entire apparatus can be reduced.

According to the automatic pressing device of the present invention, since it has the configuration described in the fourth aspect, for example, a device for gripping a workpiece (or an object) in the positioning operation of an automated machine or the handling operation of a robot hand. Can be used as In addition, in the automated machine, in addition to shortening the working time, it is possible to provide an inexpensive automatic pressing device that can cope with a small amount of work of other types and that responds to a request for automatic setup.

[Brief description of the drawings]

FIG. 1 is an embodiment of an automatic pressing device according to the present invention,
FIG. 2 is a block diagram illustrating a configuration of an apparatus that performs the automatic pressing method.

2A and 2B are diagrams illustrating a function of a contact detector in FIG. 1; FIG. 2A illustrates a change in motor drive current with respect to time before and after a movable member contacts a contact member; FIG. 2B is a diagram illustrating a change in speed of the motor rotor with respect to a similar time.

FIG. 3 is a configuration diagram of the automatic pressing device embodied in FIG. 1;

FIG. 4 is a front view of a gripping device used in the driving device of FIG. 3;

FIG. 5 is a right side view of FIG.

FIG. 6 (a) is a layout view of a movable member and a contacted member for explaining a conventional automatic pressing method, and FIGS. 6 (b) and 6 (c) are conventional automatic pressing methods. It is a figure showing each speed command pattern used for the device.

FIG. 7 is a front view showing an example of a gripping device in a conventional automatic pressing device.

FIG. 8 is a diagram showing another example of the speed command pattern used in the conventional automatic pressing device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 movable member 2 member to be contacted 10, 20 automatic pressing device 11 control command device 12, 22 control device 13 drive device 14 contact detector 22 a excitation sequence control circuit 22 b power supply circuit 22 c current control circuit 22 d motor drive circuit 22 e F / V (frequency / voltage) converter 22f Speed setting unit 22g Error amplifier 23 Gripping device HE1, HE2, HE3 Hall element M motor M1 brushless motor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Eiji Nakazawa, Inventor 1400 Shinogata, Kashiwa-shi, Chiba Oriental Motor Co., Ltd. Inventor Takeshi Mihori 1400 Shinogata, Kashiwa City, Chiba Prefecture Oriental Motor Co., Ltd. (72) Inventor Kinki 1400 Shinogatada, Kashiwa City, Chiba Prefecture Oriental Motor Co., Ltd. F-term (reference) 2F051 AA21 AB05 AB06 AC07 BA03 BA05 3F059 BA08 DA07 DD01 FC03 FC04 FC11 5H560 AA07 AA10 BB04 BB07 BB12 DA02 DA19 DB02 DC12 EB01 GG04 SS01 UA02 XA04 XA12 5H607 AA08 AA14 BB01 BB09 BB14 BB21 DD03 DD08 DD17 EE31 EE52 HH03 JJ07

Claims (4)

[Claims] 1. A motor is driven to move a movable member,
An automatic pressing method in which after the movable member is brought into contact with the contacted member, the motor is further intensified to press the movable member against the contacted member, wherein the movable member comprises the contacted member. Until contact with, the speed of the movable member and the torque of the motor are less than the allowable value,
A change in current flowing through the motor or a change in the speed of a rotor of the motor detects that the moving member has contacted the object to be contacted, and thereafter, the motor generates an increased torque. And controlling the motor to press the movable member against the abutted member. 2. A control means for instructing the control, a driving means for moving a movable member by driving a motor, and a control means for controlling the motor in accordance with a command from the control command means. An automatic pressing device that presses against the contacted member, further comprising: a unit that detects that the moving member comes into contact with the contacted object, wherein the control unit responds to a command from the control command unit. By moving the movable member in the direction of the contacted member by the driving means, until the movable member comes into contact with the contacted member, the speed of the movable member and the torque of the motor should be equal to or less than an allowable value, The contact of the moving member with the contacted object is detected by the contact detection means, and thereafter, the motor is controlled so as to generate an increased torque by the motor, and Automatic pressing device, characterized in that pressing the rotary members said the contacted member. 3. The motor is a brushless motor,
3. The automatic pressing device according to claim 2, wherein the means for detecting that the moving member comes into contact with the contacted object includes a plurality of Hall elements built in the brushless motor. 4. The method according to claim 1, wherein the movable member and the abutted member are
A gripping mechanism including a pair of opening / closing members, and after holding an object between the opening / closing members, increasing the torque of the motor and controlling the motor to generate a predetermined gripping force between the opening / closing members. The automatic pressing device according to claim 2, wherein the pressing is performed.