JPS62297088A - Direct drive robot having emergency stop function - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a direct drive robot having a mechanism for directly driving an arm by an AC servo motor or the like.

Conventional technology Recently, as industrial robots, in addition to robots that have a drive system that transmits the drive of a conventional L)C servo motor to the arm via a speed i, there are also robots that have a drive system that transmits the drive of an AC servo motor to the arm without going through a reduction gear. Direct drive robots with a drive system that transmits power directly to the arm are being developed and used.

An example of the configuration of this direct drive robot will be explained with reference to FIG. In Figure 1, 1 is an arm, 2 is a main shaft, 3 is a housing cap, 4 is a housing, and 5 is an A
C servo motor, 6 is a coupling, 7 is a position detector,
8 is a control device.

As shown in FIG. 1, the stator 6a of the AC servo motor 6 is built into the housing 4, and the rotor sb of the AC servo motor 60 is fixed to the main shaft 2. Furthermore, the arm 1 and the position detector 7 are connected to the main shaft 2 via the coupling 6, and a position signal output from the position detector 7 to the control device 8 is used to control the control device 8. The device 8 detects the position, speed, acceleration, etc. of the arm 1, and outputs a drive signal in accordance with the detected information to the AC servo motor 6 to drive it, thereby operating the arm 1. The housing cap 3 is the upper lid of the housing 4, and as shown in FIG. 1, the main shaft 2 is supported by a bearing provided between the housing cap 3 and the nose ring 4. There is.

As described above, the direct drive robot with the following configuration does not have a reducer interposed between the AC servo motor that is the drive source and the arm or the drive shaft of the arm, so it is more effective than a robot with a conventional reducer. The arm can be operated at high speed and with high precision, and when teaching a position, by turning off the AC servo motor drive signal, the arm can be held directly in the hand and moved to the desired position with light force. This robot has excellent features such as significantly shortened teaching time.

Problems to be Solved by the Invention However, in conventional direct drive robots, the spindle and arm can be operated with light force when the drive signal of the AC servo motor is turned off as described above, so when the robot is being driven, If the arm moves unexpectedly or if the arm suddenly activates due to some kind of malfunction while someone is working near the robot, immediately operate the emergency stop button to turn off all power. However, the main shaft and arm continue to operate due to inertial force, which poses a problem in that there is a high risk of harm to equipment around the robot, the operator of the device, or the robot itself.

In view of the above problems, the present invention aims to provide a direct drive robot with higher safety.

Means for Solving the Problems In order to solve the above problems, the direct drive robot of the present invention has a mechanism between the main shaft and the housing that mechanically stops the movement of the main shaft by the servo motor independently of the servo motor control. A stopper groove is provided to allow the

Function: With the above-described configuration, the stop mechanism of the present invention is removed during normal operation of the direct drive robot, and when the need for an emergency stop of the robot arises, the stop mechanism operates to stop the main shaft. By mechanically stopping the movement of the arm, equipment around the robot can be removed in an emergency.
This is designed to increase safety for equipment and workers.

EXAMPLE Hereinafter, a direct drive robot according to an example of the present invention will be described with reference to the drawings.

FIG. 2 shows the configuration of the emergency stop mechanism in the first embodiment of the present invention, and is a view taken along the line A--A in the direct drive robot shown in FIG. Note that the same numbers are given to the same components as those of the direct drive robot shown in FIG. 1.

In Fig. 2, 9 is a solenoid, 1o is a coupling plate, and 11
12 is a drive shaft, 12 is a shaft guide, 13 is a spring guide, 14 is a wedge portion, 16 is a sliding corrector, 16 is a spring, and 17 is a screw. The drive shaft 11, which has the wedge portion 14 at its tip, is moved by the shaft guide 12 to the C position shown in FIG.
The drive shaft 11 simultaneously moves the solenoid 9 through the spring 16 and the spring guide 13 that regulate the movement in the C and D directions. It is connected to the coupling plate 1o which is fixedly connected to the shaft 9a. However, the coupling plate 1o has elongated holes in the directions C and D, and a shaft portion (not shown) that is part of the drive shaft 11 and protrudes from the back side of the paper to the front side of the drawing. The drive shaft 11 has a degree of freedom in the C and D directions relative to the coupling plate 1o by the length of the elongated hole. have. Further, the spring 16 is fitted on the drive shaft 11, and the spring guide 13
Although the mechanism is such that the driving shaft 11 is always pushed in the direction C, the pushing force of the spring 16 is selected to be weaker than the attractive force of the solenoid 9. The anti-slip material 15 is attached to the distal end surface of the wedge portion 14, and when the wedge portion 14 is inserted into the gap between the housing cap 3 and the creation king 2, the anti-slip material 15 is attached. It is pressed against the surface of the main shaft 2. The screw 17 is inserted into the drive shaft 1 in order to release the wedge portion 14 from being wedged into the gap between the housing cap 3 and the main shaft 2.
1, screw into the screw hole provided at the tip in the above direction, and attach the drive shaft 11 to the housing cap 3.
It is used to pull the material in the direction mentioned above.

The operation of the emergency stop mechanism of the direct drive robot configured as described above will be explained below.

First, when the robot is in a normal operating state, the solenoid 9 is supplied with power (not shown) and is in the ON state shown in FIG. 2. As shown in the figure, in the ON state,
The solenoid 9 causes the moving shaft 9a to be pulled in the above direction, and as a result, the coupling plate 10,
The drive shaft 11 and the wedge portion 14 are also connected to the spring 1 at the same time.
The wedge portion 14 and the bezel stopper 16 are pulled in the above direction by overcoming the pushing force of 6, and the wedge portion 14 and the bevel stopper 16 are in a state of non-contact with the ujing cassop 3 and the main body 2.

Next, when the robot's emergency stop button is actuated or all power related to the robot is turned off, the power supplied to the solenoid 9 is cut off and the solenoid 9 is turned off.
FF state, and the moving axis 9a is moved to the C and D states.
released in the direction of Then, the spring 16, which is in the compressed state during the normal time described above, pushes the drive shafts 11a and 11b in the C direction, thereby causing the wedge portion 14a to open.

14b is pushed out in the C direction. Here, the main shaft 2
is rotating in the direction of FIG.
After contacting the Uzing cassop 3 and the main shaft 2, a is further pulled in the direction C by the frictional force generated between the main shaft 2 and the anti-slip material 15a, and becomes the wedge portion 14a. is inserted into the gap between the main shaft 2 and the housing cap 3, so that the raw material I1
1] Stop the rotation in the A direction of 2. At this time, the wedge portion 14b is pushed out in the C direction by the spring 16, but the frictional force generated at the point where the web stopper 15b contacts the main shaft 2 is
The coupling plate io acts to push down the bonding plate 1b in the direction mentioned above.

The drive shaft 11b moves in the upward direction within the range of the elongated hole described above, and this operation is repeated until the main shaft 2 stops rotating.

Next, when the above-mentioned emergency stop button is activated, the main shaft 2 is activated as shown in FIG.
If the wedge part 14 is rotating in direction B in
b stops the main shaft 2, but the wedge portion 14a described above
Since the operation is the same as in the case of , the explanation here will be omitted. After the main shaft 2 has stopped, the wedge portion 14 is inserted into the gap between the main shaft 2 and the housing cap 3.
To restore the drive shaft 11 to its normal state, screw the screw 17 into the screw hole cut at the tip of the drive shaft 11. From the point at which the screw 17 contacts the housing cap 3, the drive shaft 11 is This can be done until the wedge portion 14 is released.

As described above, according to this example, by adding an emergency stop brake mechanism to a direct drive robot with a simple structure in which a wedge is provided at the tip of the drive shaft operated by a solenoid and a spring, it is possible to can greatly improve safety.

Although a linearly moving solenoid is used in the embodiment, it can be easily assumed that similar effects can be obtained even if a rotating solenoid is used.

Further, there is no need to say that a plurality of brake mechanisms described in the embodiments may be provided at a plurality of locations on the main shaft of a direct drive robot.

Next, a second embodiment of the present invention will be described below with reference to the drawings.

3 and 4 show the configuration of the emergency stop mechanism in the second embodiment of the present invention, and similar to the above-mentioned FIG. 2, the A-A arrow in the direct drive robot shown in FIG. This is a perspective view. Components that are the same as those of the direct drive robot shown in FIGS. 1 and 2 are given the same numbers.

In Fig. 3, 2 is the main shaft, 3 is a nousing cap, 9 is a solenoid, 18 is a gear part, 19 is a binding material, 20
is a wedge rod, and the coupling member 19 fixedly connected to the moving shaft 9a of the solenoid 9 connects the wedge rod 20. Further, the gear portion 18 is integrally constructed with the main shaft 2 or press-fitted to the main shaft 2, and the main shaft 2 and the gear portion 18 are movable relative to the rotational direction of the main shaft 2. It has no structure.

Next, Figure 4 is an enlarged view of section P shown in Figure 3.
21, which is not shown in FIG. 3, is a leaf spring, and 22 is an elastic material. In FIG. 4, the elastic material 22 is attached to the tip of the wedge rod 2o, and as shown in the figure, the wedge rod 2o and the housing cap 3 are connected via the leaf spring 21. , the wedge rod 2o has a degree of freedom kW with respect to the nozzling cap 3 in the rotation directions G and H shown in the figure. The binding material 19 has elongated holes in the & and L directions shown in the figure, and a part of the wedge rod 20 that protrudes from the front side of the paper toward the back side (not shown) is located in the long hole. The binding material 19 and the wedge rod 2o are connected by being fitted into a hole,
The wedge rod has a degree of freedom in the L direction with respect to the binding material 19.

The operation of the emergency stop mechanism of the direct drive robot configured as described above will be explained below.

First, when the robot is in a normal operating state, the solenoid 9 is supplied with power (not shown) and is in the ON state indicated by the dotted line in FIG. 4. In the ON state as shown in the figure, the solenoid 9 moves the moving shaft 9a to 1 in the figure.
The bonding material 1 is pulled in the direction of
9 moves in the direction of I, and the wedge rod 2o
, the wedge rod 2o overcomes the pushing force of the leaf spring 21 and rotates in the direction of G. In the above-described state, the wedge rod 2o and the gear portion 18 are not in contact with each other, and the main shaft 2 can freely rotate in the directions E and F in the figure.

Next, when the robot's emergency stop button is actuated or all power related to the robot is turned off, the power supplied to the solenoid 9 is cut off and the solenoid 9 is turned off.
In the FF state, the moving shaft 9a is released in the direction 1.1 in the figure.

Then, the leaf spring 21, which is in the compressed state during the normal time described above, pushes the wedge rod 20 in the H direction, so that the wedge rod 2o comes into contact with the tooth end of the gear portion 18. Here, if the main shaft 2 is rotating in the E direction when the emergency stop button is activated, the wedge rod 20
The elastic material 22a attached to the tip of the gear part 1
8, the wedge rod 20a acts as a wedge between the welding camp 3 and the gear part 180, and instantly stops the rotation of the main shaft 2 in the E direction. Thereafter, due to the reaction by the elastic material 22a, the F
The main shaft 2 starts rotating in the direction.

This time, the wedge rod 20b is stopped by the same principle as described above, and as described above, one tooth of the gear portion 18 moves between the wedge rods 20a and 20b.

It vibrates attenuated in the direction of F and finally comes to a complete stop.

Next, when the main shaft 2 is rotating in the F direction in FIG. 4 when the emergency stop button is activated, the wedge rod 2ob first stops the main shaft 2, but in the case of the wedge rod 20a described above. Since the operation is similar to that, the explanation here will be omitted. After the main spindle 2 has stopped, when power is supplied to the robot again and the robot returns to normal operation, the wedge rod 20a,
If the main shaft 2 is rotated so that one tooth of the gear portion 18 located between 20h and 20h comes to the neutral position between the wedge rod 20a and the wedge rod 20b, the wedge rod 20a,
20b rotates in the G direction, and the robot returns to its normal operating state.

As described above, according to this embodiment, a part of the main shaft of the direct drive robot is shaped like a full gear, and an emergency stop brake mechanism of a simple structure equipped with a wedge rod operated by a solenoid and a leaf spring is added. , it is possible to greatly improve the safety when operating a direct drive robot.

Although a linearly moving solenoid is used in the embodiment, it can be easily assumed that similar effects can be obtained even if a rotating solenoid is used.

Furthermore, it goes without saying that a plurality of brake mechanisms described in the embodiments may be provided at a plurality of locations on the main shaft of the direct drive robot.

It goes without saying that the first embodiment and the second embodiment may be used in combination, and a device (for example, a cam mechanism) that can obtain the same effect may be used in place of the solenoid used in both. good.

Effects of the Invention As described above, the present invention provides a stop mechanism for stopping the operation of the main shaft between the main shaft and the housing of a direct drive robot, and turns on/off the operation of this stop mechanism.
By adding a configuration in which this is performed by a solenoid connected to the above-mentioned stopping mechanism to a conventional direct drive robot, it is possible to maintain all of the characteristics of a direct drive robot such as high speed, high precision, and easy teaching work. This makes it possible to realize an excellent direct drive robot that can improve the safety of devices, equipment, and workers around the robot in an emergency.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a conventional direct robot and a direct robot of the present invention, and FIG. 2 is an explanatory diagram of the configuration of a first embodiment of the present invention.
FIGS. 3 and 4 are explanatory diagrams of the configuration of a second embodiment of the present invention. 1... Arm, 2... Main shaft, 3...
... Housing cap, 4 ... Housing, 6 ... 1 ... AC servo motor, 6 ... Coupling, 7 ... Position detector, 8 ... ...
Control device, 9...Solenoid, 1o/1.・・・
Connection plate, 11... Drive shaft, 12... Shaft guide, 13... Spring guide, 14...
Wedge part, 16... Screw stopper, 16...
...Spring, 17...Screw, 18...
Gear part, 19... Binding material, 2o... Wedge rod, 21... Leaf spring, 22... Elastic material. Name of agent: Patent attorney Toshio Nakao and one other person
- Chapter 3 - - Toshi, Fiti, 77m 4 - - Hamajishig total - ° Betsui P S 1 Zu 9 - - 1 - L no (g I C - - i hor + horizontal 11 - - Ichi Otsu iKanshoIS゛°-S1゛°Sutate 1ginyo J/1 に１、＼'Ne 17--August 3 Figure 18 N Figure 4

Claims (1)

[Claims] a servo motor, a housing in which the servo motor is incorporated, a main shaft directly driven by the servo motor, an arm coupled to the main shaft, a control device that controls the servo motor, and a main shaft that controls the main shaft relative to the housing. A direct drive robot with an emergency stop function that is equipped with a stop mechanism that mechanically stops the operation.