JPH081399A - Press with safety mechanism - Google Patents

Abstract

PURPOSE:To obtain a press having a safety mechanism with improved safety and reliability by detecting not only a rotational quantity from a rotary encoder but also a pressure change inside a cylinder, combinedly and inputting them into the CPU. CONSTITUTION:The forward and backward revolution of a servo motor 2 in a press is transmitted to a screw shaft 7 and converted to the vertical linear motion of a follower screw member 11A, which is screwed onto the screw shaft 7 through a screw mechanism, and a pressurizing part 11C at the lower end of the follower screw member 11A. Since the capacity of a cylindrical space 32 is reduced and expanded by the vertical motion of a ram part 11A, air flows in and out through a flowing hole 30, imparting positive/negative pressure fluctuation to a pressure switch 33. Information is inputted to the CPU 40 from the pressure switch 33 and from a rotary encoder 3 for detecting the rotational quantity of the servo motor 2, enabling the CPU 40 to integrate them and judge normal/abnormal motion of the ram part 11A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press device with a safety mechanism, and more particularly to a press device having means for converting rotational movement into linear movement, and the linear movement amount is controlled by detecting the number of rotations thereof. The present invention relates to a press device with a safety mechanism for controlling the runaway.

[0002]

2. Description of the Related Art As a conventional press device having the above-mentioned configuration, one disclosed in Japanese Patent Laid-Open No. 62-259632 is known. This type converts rotational motion into linear motion by a driven screw member that is screwed into a screw member that is rotationally driven by a servomotor, and press-fits and crimps mechanical parts by pressing operation by a pressing member that is integral with the driven screw member.
It is used for press work such as drawing. In this example, the linear displacement of the pressing member is monitored by the determination unit as the amount of rotation of the screw member by the servo motor, and the pressing force of the component whose pressing force is monitored by the pressing detector is appropriately maintained. ing.

[0003]

However, in the above-mentioned conventional example, the moving direction of the pressing member and its displacement amount are determined by the microprocessor based on the counting of the output pulses from the rotary encoder which detects the rotation amount of the servo motor. Since it is configured to make a judgment, the moving direction and the displacement amount of the pressing member can be accurately detected in the case of a failure of the rotary encoder, a disconnection around the signal line, or an erroneous judgment of the microprocessor. Disappear.

It is an object of the present invention to pay attention to the above-mentioned conventional problem, and in order to solve the problem, the operation of the pressing portion is detected not only by the rotation amount from the rotary encoder but also with the pressure change in the cylinder. By doing so, it is an object of the present invention to provide a press device with a safety mechanism that can monitor the press operation even if an accident occurs in the rotary encoder, the drive system of the press, or the like.

[0005]

In order to achieve such an object, the present invention has a ram portion of a driven member having a pressing portion, which has a movement converting means for converting the rotational movement of a servo motor into a linear interlocking movement. A press device that slides along a cylinder portion by the motion converting means and performs a pressing operation by the pressing portion, the pressure detecting means detecting a change in pressure generated in the cylinder portion when the ram portion slides. And a rotation detecting means for outputting information relating to the rotational movement of the servomotor, and a control capable of judging whether or not there is an abnormality in the press device based on the detection signal from the pressure detecting means and the information from the rotation detecting means. And means.

[0006]

According to the present invention, when the ram portion of the driven member slides along the cylinder portion, the pressure change generated in the cylinder portion is detected by the pressure detecting means and the servo is detected as information from the rotation detecting means. At least the rotation direction of the motor is detected, and the pressure detection signal and information relating to the rotation direction of the servomotor are supplied to the control unit, so that the control unit determines whether or not the press machine is operating normally. Therefore, the safety and reliability of the press machine can be improved.

[0007]

Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

FIG. 1 illustrates one embodiment of the present invention, where:
Reference numeral 1 is a press device, 2 is a servomotor which is a drive source of the press device 1, 3 is a rotary encoder (rotation detecting means) attached to the servomotor for detecting the rotation speed, rotation speed and rotation direction of the servomotor 2, Reference numeral 4 is a timing pulley (or timing gear) attached to the tip of the output shaft of the servomotor 2, and 5 is a pulley or gear 4 via a timing belt (or idle gear) 6.
Is a drive pulley (or drive gear) driven by. A screw shaft 7 is fixed to the drive pulley via a pressure flange 8 and a power lock mechanism 8A, and is rotatably held on the bearing support housing 10 side via a plurality of bearings 9. Reference numeral 11 is not shown on the screw shaft 7. The driven screw member 11A screwed through the screw mechanism is a ram portion formed in a piston shape on the outer peripheral portion of the driven screw member (driven member) 11.

The ram portion 11A has a screw shaft accommodating hole 1 for keeping the screw shaft 7 rotatably in the center thereof.
1B is provided. 12 is a bearing case, 13
Is a flange member that keeps the bearing 9 together with the bearing case 12 rotatably housed, 14 is a bearing nut that keeps the flange member 13 pressed against the bearing housing 12, and 15 is inserted into the bearing portion of the screw shaft 7. The collar member 16 is a seal member that keeps the surroundings of the bearing portion airtight from the outside.

Reference numeral 17 is a column for vertically holding the press device 1 on a base (not shown), and 17A is a first guide hole formed in the column 17 for guiding the driven member 11 in the vertical direction. Further, reference numeral 18 is a push member fitted and fixed in the guide hole 17A to keep the ram portion 11A of the driven member 11 slidable. The pressing portion 11 of the driven member 11
C and the anti-rotation shaft 19 parallel to this are connected to the connection arm 20.
And the follower screw member 11 moves up and down along the second guide hole 17B provided in the column 17 as the driven screw member 11 moves up and down. Reference numeral 21 is a bush for the whirl-stop shaft 19 fitted in the second guide hole 17B.

Next, the safety mechanism according to the present invention will be described.

The bearing support housing 10 fixed to the column 17 is provided with a screw hole 10A on its side portion for attaching a pressure introducing member 31 having a through hole 30 for pressure detection. Further, the pressure introducing member 31 is provided with a pressure switch (pressure detecting means) 33 which is turned on / off by a change in the pressure inside the housing 10 and the cylindrical space 32 inside the first guide hole 17A, and is distributed. The hole 30 is open to the atmosphere.

Incidentally, the pressure switch 33 having the above-mentioned structure.
Then, when the volume of the cylindrical space 32 increases due to the lowering of the ram portion 11A, the inflow of air through the pressure circulation hole 30 is permitted, and when the ram portion 11A moves up, the cylindrical space 32 is increased. When the volume of 32 is reduced, the outflow of air is allowed. Reference numeral 40 recognizes the vertical movement and stop state of the ram portion 10A from the detection signal from the pressure switch 33 and the information signal related to the rotation direction from the rotary encoder 3, and the ram portion 10A in the press device 1 is recognized.
The CPU is a central processing unit (CPU) that determines whether or not a normal press operation is being performed.

Therefore, in the press device 1 with a safety mechanism configured as described above, the screw shaft 7 is rotated in the same direction by the forward rotation of the servo motor 2 (for example, the clockwise rotation in FIG. 1), and The rotation is transmitted to the driven member 11, and the driven member 11 descends. Here, the driven member 11
Since both of the ram portions 11A have a diameter sufficiently larger than the diameter of the screw shaft 7, the volume of the cylindrical space 32 increases as the driven screw member 11 descends. And space 3
2 increases, air flows into the space 32 through the flow hole 30, but the pressure switch 33 provided in the pressure introducing member 31
As a result, a negative pressure is generated in the space 32 and the pressure switch.

Thus, by transmitting the negative pressure generation state to the CPU 40 via the pressure switch 33, C
In the PU 40, the ram portion 10A is detected by the normal rotation of the servo motor 2 based on the information about the rotation direction from the rotary encoder 3 and the switch switching state from the pressure switch 33.
It is determined that the normal pressing operation by is performed. Further, when the screw shaft 7 is rotated in the same direction by the rotation of the servo motor 2 in the opposite direction and the driven member 11 rises, the welding of the cylindrical space 32 shrinks as the driven member 11 rises. Then, the air is discharged through the pressure introducing member 31 by the amount of the reduced volume. Since the space 32 is maintained at a positive pressure during such air discharge, the positive pressure is detected via the pressure switch 33.

Therefore, in the CPU 40, the pressure switch 33
From the positive pressure detection signal from the rotary encoder 2 and the information (reverse rotation) from the rotary encoder 2 concerning the rotation direction of the servo motor 2, it is determined that the servo motor 2 is normally pulling up the ram portion 11A. When neither positive pressure nor negative pressure is detected via the pressure switch 33, the ram portion 11A
When it is determined that the operation by the CPU 4 has not been performed, the information related to the rotation direction from the rotary encoder 3 is output from the CPU 4
When 0 is input, it is determined that the press device 1 itself has an abnormality.

The flow hole 3 provided in the pressure introducing member 31.
By reducing the diameter of 0, it is possible to improve the accuracy of pressure change detection. Therefore, in the case of a specification in which the reciprocating speed of the ram portion 11A is slow, the pressure introducing member 31 with a small diameter of the flow hole 30 You may make it convert into.

In the embodiment described above, the first guide hole 17A
The change in the volume of the cylindrical space 32 formed in the above is detected by detecting the positive and negative pressures by the pressure switch 33. However, the pressure detecting means is not limited to the pressure switch, and is accompanied by the change in the volume of the space 32. Any form may be used as long as it is a pressure sensor capable of detecting at least positive and negative pressure generated.

Although not particularly shown, the first guide hole 17
The second guide hole 17B is formed in the shape of a cylinder having a bottom instead of A, and it is detected by the pressure detecting means as described above that the volume of the cylindrical space changes above and below the rotation stopping shaft 19. You may do it. Furthermore, a plunger cooperating with the ram portion 11A is provided along a third guide hole (not shown) parallel to the first guide hole 17A and the second guide hole 17B, and the third guide hole is operated by the operation of the plunger. It is also possible to configure so that the pressure change of the bottomed cylinder portion formed in the above is detected by the pressure detecting means as described above, and the pressure detecting means is provided separately from the flow hole 30 in the vicinity of the top of the cylinder. You may make it provide directly.

[0020]

As described above, according to the present invention, the ram portion of the driven member having the pressing portion having the movement converting means for converting the rotational movement of the servo motor into the linear interlocking movement is converted into the movement. A pressure device that slides along a cylinder portion by means and performs a pressing operation by the pressing portion, the pressure detecting means detecting a change in pressure generated in the cylinder portion when the ram portion slides; A rotation detection unit that outputs information relating to the rotational movement of the servomotor, and a control unit that can determine whether or not there is an abnormality in the press device based on the detection signal from the pressure detection unit and the information from the rotation detection unit. Since it is equipped, it is possible to confirm the pressing and pulling operations by the ram from both the detection of the rotation direction of the servo motor and the pressure change in the cylinder where the ram operates. There is a failure in the rotation detecting means also enables monitoring the execution of the press operation, without requiring a high cost with a simple structure, the safety of the device, can contribute to improvement in reliability.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a configuration according to the present invention.

[Explanation of symbols]

 1 Press Device 2 Servo Motor 3 Rotary Encoder (Rotation Detection Means) 7 Screw Shaft 9 Bearing 10 Bearing Support Housing 11 Driven Screw Member (Driven Member) 11A Ram Part 11C Pressing Part 16 Sealing Member 17 Column 17A First Guide Hole 17B 2nd Guide hole 18 Bush member 19 Non-rotating shaft 30 Flow hole (for pressure detection) 31 Pressure introducing member 32 Cylinder-shaped space 33 Pressure switch (pressure detection means) 40 CPU

Claims (6)

[Claims] 1. A ram part of a driven member having a pressing part, which has a motion converting means for converting the rotational motion of a servomotor into a linear interlocking motion, and the ram part of the driven member is slid along the cylinder part by the motion converting means, thereby pressing the ram. A press device that performs a pressing operation by a portion, the pressure detecting means detecting a change in pressure generated in the cylinder portion when the ram portion slides, and a rotation detecting portion that outputs information related to the rotational movement of the servo motor. A press device with a safety mechanism, comprising: means and a control means capable of determining whether or not there is an abnormality in the press device based on a detection signal from the pressure detection means and information from the rotation detection means. 2. The motion converting means comprises a screw shaft rotated by the servo motor, and a driven shaft screwed onto the screw shaft and restricted in rotation by a restricting means. The press device with a safety mechanism according to claim 1. 3. The pressure detecting means includes a pressure detecting pipe communicating with the cylinder portion which is kept airtight, and a pressure sensor arranged in the pressure detecting pipe for detecting a pressure change in the pressure detecting pipe. It is comprised, The press device with a safety mechanism of Claim 1 or 2 characterized by the above-mentioned. 4. The pressure change detected by the pressure detecting means is a positive or negative change in pressure generated in the cylinder portion when the ram portion slides along the cylinder portion. Item 3. A press device with a safety mechanism according to item 3. 5. The safety mechanism according to claim 1, wherein the rotation detection means is a rotary encoder, and at least the rotation direction of the servo motor is detected by the rotary encoder. Press machine. 6. The control unit determines whether the press device has an abnormality based on the positive / negative of the pressure in the cylinder portion detected by the pressure detection unit and the rotation direction of the servo motor detected by the rotation detection unit. The press device with a safety mechanism according to any one of claims 1 to 5, wherein the presence or absence is judged.