JPH0819978A - Robot device for low temperature environment - Google Patents

Abstract

PURPOSE:To apply a robot for a low temperature environment to a general environment and to a special environment without using any special part. CONSTITUTION:If a controller internal temperature detected by a temperature sensor 18 is lower than the set value when a power source is turn on, regenerative resistors 24A, 24B are energized via discharging relay contacts 26Aa, 26Ba, so that the regenerative resistors 24A, 24B are heated, and as a result, the internal temperature of the controller is increased. In a mechanism unit of a robot, if an internal temperature of an encoder case is lower than the set value, a driving motor is seized by a brake and is energized, and because of the generated heat, the internal temperature of the encoder case is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot device used in a low temperature environment.

[0002]

8 to 10 are views showing a conventional robot apparatus for a low temperature environment, FIG. 8 is an overall configuration diagram, FIG. 9 is a block diagram showing a temperature control section of a control device, and FIG. 10 is a control device. It is a block diagram showing a power supply unit, a control unit and a drive unit of
The same reference numerals indicate the same parts. Note that FIGS. 9 and 10 show only one drive motor for the sake of simplicity.

In FIG. 8, (1) is an AC power source and (2) is a hermetically sealed robot controller, which is a power source section (3), control section (4), drive section (5), heater (6) of electronic equipment. ) And a temperature control unit (7) for controlling the power supply unit (3) and the heater (6) according to the temperature inside the control device (2). (8) is a robot mechanism section, which includes an arm,
It has a drive element (9) composed of a speed reducer, a transmission, a drive motor, a pulse encoder, a braking brake, and the like.
(10) is a heater shown in FIG. 9, and (11) is a temperature sensor.

In FIG. 9, (9A) is a drive motor of the robot, (9B) is a brake for restraining the drive motor (9A),
(9C) is an electronic pulse encoder that is directly connected to the drive motor (9A) and detects the rotation of the drive motor (9A) .The pulse encoder (9C) is housed in the case (12). A heater (10) and a temperature sensor (11) are provided.

(13) is a power switch consisting of a bidirectional thyristor inserted between the power source (1) and the power source section (3), and (14) and (15) are respectively on the power source side of the heaters (6) and (10). Power switch inserted, (16) power circuit connected to the power supply (1), (17) power circuit (16), temperature sensor (11), power switch (13) ~ (15)
And a temperature control circuit connected to the temperature sensor (18).

In FIG. 10, (19) is a rectifier connected to the power source (1) through a power switch (20), and (21) is a rectifier (1
The smoothing capacitor connected to the DC side of 9), and the inverter (22) connected to the smoothing capacitor (21), the drive motor (9A) of which is connected to the AC side. (23) is an inverter (2
2) Current detector for detecting output current, (24) Inverter
A regenerative resistor connected between the DC buses of (22) via a transistor switch (25), (26) is a transistor switch (25)
A normally closed contact of a discharge relay (not shown) connected to both ends of the power supply, (27) a control power supply connected to the power supply (1), (28) a smoothing capacitor (21) and a current detector (23) Is a detection circuit connected to.

Reference numeral (29) is an interface circuit connected to the encoder (9C), (30) is an arithmetic circuit (CPU) connected to the interface circuit (29) and the detection circuit (28), and (31) is a detection circuit ( 28), arithmetic circuit (30), brake (9B), inverter (2
2), a drive circuit connected to the transistor switch (25) and the power switch (20).

The conventional robot apparatus for low temperature environment is constructed as described above, and its operation will be described below. When the power supply (1) is turned on, the temperature sensor (18) detects the ambient temperature of the electronic device of the control device (2), and the temperature sensor (11) detects the ambient temperature of the encoder (9C) of the mechanism section (8). Then, each is input to the temperature control circuit (17). The temperature control circuit (17) turns on or off the power switches (13) to (15) according to the detected temperature to supply or cut off power to the heaters (6) and (10) and the power supply section (3).

When the internal temperature of the control device (2) is lower than the allowable operating temperature, the power switch (14) is turned on to turn on the heater.
The power (1) is supplied to (6) to heat the inside of the control device (2). After the temperature inside the controller (2) rises and the electronic device reaches the allowable temperature, turn on the power switch (13) to turn on the power supply.
The power source (1) is supplied to the control unit (4) and the drive unit (5).

Then, in the power source section (3), the discharge relay is energized to open the contact (26). Now the AC of the power supply (1) is converted to DC by the rectifier (19) and the smoothing capacitor (21)
Is charged. When the detection circuit (28) detects that the voltage of the smoothing capacitor (21) has reached a predetermined voltage, the drive unit (5) causes the inverter (22) and its drive circuit (31) and current detector (23).
Is enabled and power can be supplied to the drive motor (9A). In other words, the current can be controlled, the encoder (9C) is supplied with power, and the output is taken into the arithmetic circuit (30) through the interface circuit (29), which enables speed control and position control. , The robot becomes operable.

In the mechanical section (8), the encoder case
When the internal temperature of (12) is lower than the allowable operating temperature, the power switch (15) is turned on to supply the power (1) to the heater (10) to heat the inside of the encoder case (12). After the temperature inside the encoder case (12) has risen and reached the allowable operating temperature, the robot can be operated by supplying the power (1) to the encoder (9C). Encoder (9C)
The power is supplied to the control device (2) after the internal temperature of the control device (2) stabilizes at the allowable operating temperature, power is supplied to the devices of the device, and control preparation is completed.

When the temperature inside the control device (2) and the inside of the encoder case (12) has reached the permissible temperature after the power supply (1) is turned on, the heaters (6) and (10) remain off. The robot starts up according to the above procedure. In other words, this robot turns on the heaters (6) and (10) when it is used at a low temperature as described above, and turns off the heaters (6) and (10) when it is at room temperature. Furthermore, since this robot constantly monitors the internal temperature of the robot with the temperature sensors (18) and (11),
When the temperature approaches the minimum value in the allowable operating temperature range after the power supply (1) is turned on and during operation, the heaters (6) and (10) turn on, and if it is within the allowable operating temperature range, the heater (6) ( Turn on 10).

After the robot starts up, the operation circuit (30) operates to drive the motor through the drive circuit (31) and the inverter (22).
Although (9A) is controlled and the robot is speed-controlled and position-controlled, the details are omitted. The regenerative power generated from the motor (9A) during deceleration of the robot is the transistor switch (25) due to the voltage of the smoothing capacitor (21).
Is switched at a constant cycle to energize the regenerative resistor (24) for consumption.

[0014]

In the conventional robot device for low temperature environment as described above, the control device (2) and the mechanism part (8) are used.
The heaters (6) and (10) are heated by energizing them to the heaters (6) and (10) to keep the ambient temperature within the allowable operating temperature range. Must be added,
When the heater (6) is added to the control device (2) having a high packaging density, the device becomes large and expensive. Also, encoder case (1
When the heater (10) is added in 2), the control device (2) and mechanical
(8) Wiring between them increases, resulting in high cost.

Further, in a low temperature environment, general specifications are not applicable, and therefore a robot with special specifications that can cope with the environment must be made, but the special specification product cannot be directly applied to the general environment. There is a point.

The present invention has been made in order to solve the above problems, and provides a robot device for a low temperature environment which can easily cope with a low temperature environment from a general environment without using special parts. The purpose is to provide.

[0017]

According to a first aspect of the present invention, there is provided a robot apparatus for low temperature environment, wherein a first temperature sensor for detecting a temperature is provided in a control device, and a temperature detected by the first temperature sensor is set to a first setting. When the value becomes lower than the value, a contact for connecting a resistor for consuming regenerative power between a DC bus connecting the rectifier and the inverter is provided.

Further, in the robot apparatus for low temperature environment according to the second aspect of the present invention, the second temperature sensor for detecting the ambient temperature of the encoder and the temperature detected by the second temperature sensor during the stop of the drive motor are higher than the second set value. A restraint energizing means for energizing the drive motor in a state where the drive motor is restrained when it becomes lower is provided.

A robot apparatus for low temperature environment according to a third aspect of the present invention is the robot apparatus for low temperature environment according to the first and second aspects of the present invention, wherein an air path provided in the control device or the mechanical section and high pressure air connected to the air path are provided. And an air source device for delivering the air.

The robot device for low temperature environment according to the fourth aspect of the present invention has the air passage and the air source device of the third aspect in the mechanical portion, and the solenoid valve for opening and closing the air flow is inserted in the air passage to increase the high pressure. A flow rate sensor that detects the flow rate of air and an air flow control circuit that controls the solenoid valve by the output of this flow rate sensor are provided.

[0021]

In the first aspect of the present invention, the temperature inside the control device is detected, and when the temperature becomes lower than the first set value, the resistor for consuming regenerative electric power is connected between the DC bus lines. Is heated by energization, and the inside of the control device is heated.

Further, in the second invention, the ambient temperature of the encoder is detected, and when the ambient temperature is lower than the second set value, the drive motor is energized while the drive motor is restrained, so that the drive motor generates heat. , The encoder is heated.

Further, in the third aspect of the invention, since the high-pressure air is sent to the air passage provided in the control device or the mechanism part, the temperature rise in the control device or the mechanism part becomes faster.

Further, in the fourth aspect of the invention, the temperature of the mechanical section is detected by detecting the flow rate of the high-pressure air, so that the mechanical section does not need a temperature sensor.

[0025]

【Example】

Example 1. 1 to 4 are views showing an embodiment of the first and second inventions of the present invention, FIG. 1 is a block diagram of a main part of a control device, FIG. 2 is an overall configuration diagram, and FIG. Flow chart of regenerative resistance control and control operation of drive motor,
FIG. 4 is an explanatory diagram of the operating temperature, and the same parts as those of the conventional device are indicated by the same reference numerals (the same applies to the following embodiments).

In FIGS. 1 and 2, (24A) and (24B) are resistors for consuming regenerative power and increasing temperature, (25A) and (25B) are transistor switches, and (26A) and (26B) are bidirectional thyristors, respectively. Is a discharge relay connected to the power supply (1) through the power switch (41A) (41B), (26Aa) (26Ba) is its normally-closed contact, and is connected to both ends of the transistor switch (25A) (25B). It is connected. (42) is the power supply via the power switch (43)
A busbar relay connected to (1), a normally open contact (42a) of which is inserted between the smoothing capacitor (21) and the inverter (22).

Reference numeral (44) is a control device (2) having a closed structure in a general environment.
A heat exchanger used for the above, which suppresses a temperature rise inside the control device (2) by exchanging heat between the air inside and outside the control device (2).

Next, the operation of this embodiment will be described with reference to FIGS. When the power (1) is turned on, step S
At 1, it is determined whether the internal temperature Tcon of the control device (2) is lower than the set temperature T1. If the temperature is lower than the set temperature T1, proceed to step S2 to turn on the power switch (20)
Supply power to (3). At this time, the discharge relay (26A) (2
Since 6B) is deenergized and the contacts (26Aa) (26Ba) are closed, the regenerative resistors (24A) (24B) are energized in step S3 and the regenerative resistors (24A) (24B) generate heat. Raise the internal temperature. Then, the process returns to step S1 and the above operation is repeated.

While the regenerative resistors (24A) and (24B) are energized, the control unit (4), the inverter (22) of the drive unit (5), the drive circuit (31) and the like are unstable, so that the contact (42a ) Separates the smoothing capacitor (21) and the inverter (22). Step S1
When it is determined that the internal temperature Tcon has reached the set temperature T1, the process proceeds to step S4 and the internal temperature Tcon is set to the set temperature T1.
Determine if lower than 2. When the temperature is lower than the set temperature T2, the process proceeds to step S5, power is supplied to each device of the control unit (4) and the drive unit (5), and the power switch (41
Turn on A) (41B) (43).

As a result, the discharge relays (26A) (26B) are energized, the contacts (26Aa) (26Ba) are opened, and the energization of the regenerative resistors (24A) (24B) is stopped. Further, the bus relay (42) is energized, the contact (42a) is closed, and the inverter (22) is connected to the smoothing capacitor (21). In this state, the encoder (9C)
Since it has not been activated yet, the mechanism part (8) cannot be controlled, but the current control of the drive motor (9A) is possible.

Next, in step S7, the encoder case (1
2) Determine whether the internal temperature Tenc is lower than the set temperature T3. When the temperature is lower than the set temperature T3, the process proceeds to step S8, and a current equal to or lower than the stop friction force of the brake (9B) is passed to the drive motor (9A) while the brake (9B) is applied. With this, the encoder (9C) is heated by the heat generated by the motor loss. Then, by returning to step S7 and repeating the above operation, the temperature of the encoder (9C) rises.

When it is determined in step S7 that the internal temperature Tenc of the encoder case (12) has reached the set temperature T3, the process proceeds to step S9, power is supplied to the encoder (9C),
The drive motor (9A) and the mechanism section (8) can be controlled, and the robot is ready for operation. Note that the operation of the robot is not directly related to the present invention, and therefore its explanation is omitted.

When the internal temperature Tcon is judged to be equal to or higher than the set temperature T2 in step S4, the operation proceeds to step S10, the heat exchanger (44) is operated, and the regenerative resistors (24A) (24B) and the drive motor (9A) are operated. Start up without preheating by energizing). Note that FIG. 4 shows a specific example of the set temperatures T1 to T3. In the figure, A is the allowable operating temperature range, B is the regenerative resistance (24A) (24B) energization temperature range, motor (9A) constraint energization temperature range, and C is the heat exchanger (44) operation range.

The set temperatures T1 and T3 prevent the electronic equipment from being out of the allowable operating temperature range A due to the temperature decrease and ensure that the power is supplied at the allowable operating temperature. is there. Set temperature T2 is control device (2)
In order to prevent the internal temperature Tcon from being out of the allowable operating temperature range A due to heat generation, the heat exchanger (44) has a necessary temperature.

Example 2. This embodiment shows another embodiment of the second invention of the present invention. That is, Example 1
Now, in order to heat the drive motor (9A), the brake (9
Although the drive motor (9A) is constrained to be energized by applying B), it is provided with a mechanism for temporarily fixing the drive motor (9A) and the speed reducer, arm and the like of the mechanism section (8). Even in this case, the same effect as that of the first embodiment can be obtained.

Example 3. FIG. 5 shows the first and second aspects of the present invention.
8 is a flowchart of a regenerative resistance control operation and a control operation of a drive motor at the time of temperature decrease, showing another embodiment of the invention.
Note that FIGS. 1, 2 and 4 are also used in the third embodiment. This embodiment takes into consideration the case where the temperature of the surrounding environment is lowered for some reason or the operation is stopped in the first embodiment. In the embodiment, the regenerative resistor (24A) is dedicated to regenerative power consumption, and the regenerative resistor (24B) is used for both regenerative power consumption and temperature rise.

The robot is decelerating and the controller
When the internal temperature of (2) is room temperature, the regenerative resistance (24A) is energized by the transistor switch (25A) to consume regenerative power. When the robot is decelerating and the internal temperature is lower than the allowable operating temperature range A, the transistor switch (25A) energizes the regenerative resistor (24A) to consume regenerative power, and the transistor switch (25B) regenerates it. Energize the resistor (24B) to raise the internal temperature. At this time, the regenerative resistor (24B) may be energized by the contact (26Ba).

Next, the processing during the operation stop will be described with reference to FIGS. 4 and 5. In step S11, it is determined whether the internal temperature Tcon is lower than the set temperature T1. If the temperature is lower than the set temperature T1, the transistor switch (2
5A) (25B) energize the regenerative resistor (24A) (24B) to raise the internal temperature. Further, in step S11, the internal temperature Tco
When it is determined that n has reached the set temperature T1, it is determined in step S13 whether the internal temperature Tenc of the encoder case (12) is lower than the set temperature T3. If it is lower than the set temperature T3, the brake is performed in step S14. Act (9B),
In step S15, the drive motor (9A) is energized to raise the internal temperature of the encoder case (12).

Next, in step S16, it is determined whether or not the activation is instructed. If there is no instruction, the process returns to step S11, and if there is an instruction, the process proceeds to step S17. In this state, the internal temperature Tcon, Te of the control device (2) or the encoder case (12) is
Since nc is less than or equal to the set temperatures T1 and T3, respectively, and the drive motor (9A) is restricted, the start instruction is not accepted in step S17, an alarm is displayed on a display (not shown) in step S18, and the process proceeds to step S11. Return.

When it is determined in step S13 that the internal temperature Tenc of the encoder case (12) has reached the set temperature T3, the energization of the drive motor (9A) is stopped and the alarm is canceled in step S19, and then step S20. Accept the start instruction with. In this way, even if the ambient temperature changes or the temperature drops during operation stop, the robot can be used correspondingly.

When the robot is decelerating and the regenerative power is consumed when the temperature is lower than the allowable operating temperature range A,
Unlike at room temperature, one regenerative resistor (24A) has to be consumed, so the smoothing capacitor (21) may be overvoltage. To prevent this, set the switching cycle of the transistor switch (25A) to the smoothing capacitor (21).
It may be changed according to the voltage rise time and the voltage drop time.

Example 4. FIG. 6 is a block diagram showing an embodiment of the third invention of the present invention. In the figure, (51) is an air source device for delivering high pressure air for driving the hand device (52), and (5)
3) is connected to the air source device (51) and controls high pressure air (2)
And an air duct for supplying to the encoder case (12).

The internal temperature rise value and temperature rise time of the control device (2) and encoder case (12) in the first embodiment depend on the heat generation amount and thermal time constant of the regenerative resistor (24A), drive motor (9A), etc. Therefore, in order to obtain a higher temperature rise value in a shorter time than the current situation, they must be changed. Therefore, in the fourth embodiment, high pressure air is supplied from the air source device (51) to the control device (2) and the encoder case (12) so that the inside pressure is increased.

As a result, a higher temperature rise value can be obtained faster than in the first embodiment. Therefore, the effect of increasing the internal temperature of the control device (2) and the encoder case (12) can be further improved without changing the parts. Further, unlike the third embodiment, the number of times when the activation instruction is not accepted is reduced, so that the robot becomes easier to use.

Example 5. FIG. 7 is a block diagram showing an embodiment of the fourth invention of the present invention. Note that FIG. 4 is also used in the fifth embodiment. The embodiment 5 is the one shown in FIG. 6, in which the solenoid valve (55) is provided in the air line (53) on the inlet side of the encoder case (12).
Similarly, insert the solenoid valve (56) and the flow sensor (57) into the air pipe (53) on the outlet side, and insert the flow sensor (5) into the control unit (4).
The interface circuit (58) connected to 7) is added. The solenoid valves (55) (56) are connected to the drive circuit (31).

That is, the high pressure air supplied from the air source device (51) flows back through the solenoid valve (55), the encoder case (12), the solenoid valve (56) and the flow rate sensor (57). The air flow is detected by the sensor (57) and the interface circuit
It is taken into the arithmetic circuit (30) via (58). Flow sensor
Since the flow rate detected by (57) differs depending on the temperature, the internal temperature of the encoder case (12) can be known from the output of the flow rate sensor (57). That is, the flow sensor (57) acts as a temperature sensor.

When the internal temperature is low (less than T3), high pressure air is sent to the encoder case (12) through the solenoid valve (55) to make the inside high pressure. The drive motor (9
When the internal temperature rises due to the heat generated by A), the internal pressure becomes even higher. Here, the solenoid valve (56) is opened for a short time, and the internal temperature is measured by the flow rate sensor (57) as described above. When the internal temperature is room temperature (T3 to T4), the solenoid valves (55) and (56) are intermittently opened and closed to allow air to flow to suppress the temperature inside the encoder case (12). If the internal temperature is high (T4 or higher), always open the solenoid valves (55) (56),
Forced air cooling controls the temperature inside the encoder case (12).

Therefore, the temperature sensor (11) of the mechanism section (8) used in each of the above embodiments is unnecessary, and the control unit (2)
There is no need for wiring between the and mechanical section (8). Drive motor
Encoder when (9A) is used with an overload or heat is increased due to repeated acceleration / deceleration with high frequency
It can also be used as a heat dissipation means for (9C).

[0049]

As described above, according to the first aspect of the present invention, the temperature inside the control device is detected, and when the temperature becomes lower than the first set value, the resistor for regenerative power consumption is connected between the DC bus lines. As a result, the resistance heats up when energized, heats the inside of the control device, and has the effect of easily adapting from a general environment to a low temperature environment without using special parts.

In the second aspect of the invention, the ambient temperature of the encoder is detected, and when it becomes lower than the second set value, the drive motor is energized while the drive motor is restrained, so that the drive motor generates heat. , The encoder is warmed up,
The same effect as the first invention is obtained.

Further, in the third aspect of the invention, since the high-pressure air is sent to the air path provided in the control device or the mechanism part, the temperature rise in the control device or the mechanism part is quick, and the robot is easy to use. There is an effect that can be.

Further, in the fourth invention, the temperature of the mechanical section is detected by detecting the flow rate of the high-pressure air, so that the mechanical section does not need a temperature sensor, and the wiring between the control device and the mechanical section is not required. There is an effect that can be made unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of a control device showing a first embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing a first embodiment of the present invention.

FIG. 3 is a flow chart of a regenerative resistance control and a drive motor control operation at the time of turning on the power, showing the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of operating temperature in FIG.

FIG. 5 is a flow chart of a regenerative resistance control and a drive motor control operation at the time of temperature decrease, showing Embodiment 3 of the present invention.

FIG. 6 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 7 is a block diagram showing a fifth embodiment of the present invention.

FIG. 8 is an overall configuration diagram of a conventional low-temperature environment robot.

9 is a block diagram showing a temperature control unit of the control device of FIG.

10 is a block diagram showing a power supply unit, a control unit, and a driving unit of the control device of FIG.

[Explanation of symbols]

1 power supply, 2 control device, 8 mechanism parts, 9A drive motor, 9B braking brake, 9C pulse encoder,
10 heater, 11 second temperature sensor, 12 encoder case, 18 first temperature sensor, 19 rectifier, 22
Inverter, 24A, 24B Regenerative resistor, 25A, 25
B transistor switch, 26Aa, 26Ba discharge relay contact, 51 air source device, 53 air path (air line), 55, 56 solenoid valve, 57 flow sensor, T
con Controller internal temperature, Tenc encoder case internal temperature, T1 first set value, T3 second set value.

Claims (4)

[Claims] 1. A controller has a rectifier and an inverter connected to each other by a DC bus, converts AC into DC through the rectifier, converts the AC into AC by the inverter, and drives a robot drive motor. In addition, in a device in which a resistor that consumes the power when the motor is regenerated is connected between the DC buses, the first temperature sensor that detects the temperature in the control device and the temperature detected by the first temperature sensor are A robot device for low-temperature environment, comprising: a contact for connecting the resistance between the DC buses when the value is lower than 1 set value. 2. A device having a robot drive motor and an encoder for detecting the rotation of the motor, wherein a second temperature sensor for detecting an ambient temperature of the encoder and a temperature detected by the second temperature sensor while the drive motor is stopped. Is lower than the second set value, the robot device for a low temperature environment is provided with a constraint energizing means for energizing the drive motor while the drive motor is constrained. 3. The air supply device according to claim 1, further comprising an air passage provided in the control device or the mechanical portion, and an air source device connected to the air passage and delivering high-pressure air. Robot device for low temperature environment. 4. An air path provided in the mechanism section, an air source device connected to the air path for delivering high-pressure air, an electromagnetic valve inserted into the air path to open and close the air flow,
The robot apparatus for a low temperature environment according to claim 2, further comprising: a flow rate sensor that detects a flow rate of the high-pressure air, and an air flow control circuit that controls the electromagnetic valve based on an output of the flow rate sensor.