JP3325922B2 - Electric press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric press for processing a small and small-capacity workpiece W precisely and accurately.

[0002]

2. Description of the Related Art With respect to press technology, there have been roughly classified into mechanical presses, hydraulic presses, foot presses, air presses and the like.

[0003]

Conventional presses, although somewhat different in their applications, are generally large in size and large in capacity, and cannot perform precise press work.

[0004]

The inventor of the present invention has conducted intensive studies to solve the above-mentioned problems. As a result, the present inventors have found that the present invention uses an electric motor as a main drive source of a press, and uses the height of each ram of a press ram. In the position, control the speed and pressure,
A small and small-capacity workpiece W can be machined precisely and accurately, and the above-mentioned problem has been solved. In addition, the central processing unit and its related devices command various functions to the ram to the electric press equipped with a mechanism that converts the rotational force of the electric motor into linear motion by making the most of its characteristics to enable a flexible response. It is configured as follows.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 5 and 6, the electric press of the present invention , A ball screw 2 for raising and lowering the ram 1, and an electric motor 3, which are provided in a head frame of a casing 4.

First, as shown in FIG. 5, the structure of the ram 1 is formed in a cylindrical body. Specifically, the ram 1 is axially inserted into a cylindrical main body 1a formed in a cylindrical shape. A hollow portion is formed along the axis, and the screw shaft 2a of the ball screw 2 can be inserted into the hollow portion. The nut body 2b of the ball screw 2 is fixed.

A pressing body 1b is provided at the lowermost part of the cylindrical main body 1a.
The pressing body 1b actually comes into contact with the workpiece W to apply an appropriate pressure. Further, a strain gauge is attached to the pressing body 1b. In some cases, the pressure applied to the workpiece W can be detected by the strain gauge.

A cylindrical guide 5 is provided so as to surround the outer peripheral side surface of the cylindrical main body 1a. The cylindrical guide 5
Is fixed in a casing 4 and the ram 1 can move up and down along a cylindrical guide 5. The ram 1
Is provided with a steady rest guide 6 so as not to rotate on a plane orthogonal to the axial direction. As shown in FIGS. 5 and 6, the steady rest guide 6 comprises a steady rest rod 6a, a guide part 6b and a connecting plate 6c. The steady rest rod 6a is located above the lower end of the ram 1. And is provided in parallel with the ram 1 via the connecting plate 6c so that the steadying rod 6a moves in the vertical direction as the ram 1 moves up and down.

Further, a guide portion 6b for allowing the steadying rod 6a to pass through a predetermined location is fixed in the casing 4,
The wobble rod 6a moves up and down along the guide portion 6b, so that the ram 1 does not idle in the cylindrical guide 5 when moving in the vertical direction. .

Above the sway bar 6a, a swelling switch operating portion S is formed, and an upper limit switch Us and a lower limit switch Ds as limit switches for setting a stroke range of the ram 1 provided in the casing 4 are provided. It is configured to operate.

Specifically, the upper limit switch Us is connected to the ram 1
When the upper end of the switch operating portion S of the oscillating rod 6a linked to the ram 1 is operated, the central processing unit (CPU) 11 sends a signal to the motor driver 12, The ram 1 stops rising. This prevents the nut body 2b of the ball screw 2 that moves too high and interlocks with the ram 1 from colliding with the upper end bearing. on the other hand,
The lower limit switch Ds is for regulating the lower limit point of the ram 1. When the lower limit switch Ds is operated by hitting the lower end side of the switch operating portion S of the steadying rod 6a fixed to the ram 1, the central processing unit (CPU) 11 drives the motor. Sends a signal to the driver 12,
The ram 1 stops descending. This prevents the nut body 2b of the ball screw 2 from coming off due to excessive lowering.

As described above, if the upper limit switch Us of the ram 1 is set as the upper limit switch Us as the ram upper limit control means A, it is possible to prevent the ram 1 from being damaged due to rising. The ram upper limit control means A comprises setting means A1 for setting the ascending limit position of the ram 1, and phase detecting means A2 for the ram 1 for detecting the reference position of the ram 1.

When the lower limit switch Ds, which is a limit switch, sets the lower limit point of the ram 1 as the ram lower limit control means F, it is possible to prevent the nut or the like from coming off due to the lowering and prevent the ram 1 from being damaged. The ram lower limit control means F is constituted by setting means for setting a lower limit position of the ram 1.

On the lower side of the casing 4, a base 8 is provided on the near side via a vertical column 7 and directly below the ram 1.
The operation buttons 9a and 9b are provided in front of the base 8, and have a function of lowering, temporarily stopping, and raising the ram 1. Specifically, when lowering the ram 1, the operation buttons 9a and 9b are simultaneously pressed, and when the ram 1 is temporarily stopped, the operation button 9a is pressed and only the operation button 9b is released.
Further, when the operation buttons 9a and 9b are simultaneously released, the ram 1 is released.
Is configured to rise.

The controller 10 provided on the front side of the casing 4 has various switches, buttons, and the like from 10a to 10i.

The power switch 10a and the storage setting button 10b are used for setting and changing various storage points. Reference numeral 10c denotes a corresponding height setting button for setting a rising position corresponding to the height of the workpiece W, 10d denotes a press-fitting work start setting button, and 10e denotes a press-fitting stop setting button. 10f is a digital switch as a code generator, which is used for correcting a fixed position stop point. For example, when the correction value is set to the digital switch 10f and the addition or subtraction is instructed by the sign change switch 10g, the central processing unit (CPU) 11 performs the calculation and sets the point by the press-fitting work start setting button 10d. Is changed. 10h is an upper limit pressure setting button, and 10i is a lower limit pressure setting button.

The central processing unit (CPU) 11 stores a corresponding height set point of the ram 1, a switching point from high speed to low speed, a set pressing force generation point, and a fixed position stop point. It has a function of detecting that the ram 1 has reached the position, and instructing the electric motor 3 to change the setting of the rotation speed and the current value, and to intermittently and invert.

The motor 3 is driven by a motor driver 12 according to a command from the central processing unit 11. An encoder 13 for detecting a reference position of the ram 1 is connected to the electric motor 3, and thereby detects a moving amount and a speed of the ram 1.

Reference numeral 14 denotes a current setting circuit.
Has a function of converting a signal from a digital to an analog and sending the converted signal to the motor driver 12.

Next, the setting and configuration of the press-fitting operation will be described. When the power switch 10a on the control unit 10 is turned on, a rising signal for setting the origin is sent from the central processing unit 11 to the motor driver 12, and the motor 3 Is driven, the ram 1 starts to rise, and when the switch operating portion S connected to the ram 1 presses the upper limit switch Us serving as a limit switch to detect the rising limit point of the ram 1, the central processing unit After 11 stops the motor 3,
Invert and drive.

Next, after pressing the memory setting button 10b to bring the central processing unit 11 into the state of taking in various memories, the operation button 9a and the operation button 9b are simultaneously pressed to release the RAM 1
Is lowered, the operation button 9a is pressed, the operation button 9b is released, the ram 1 is temporarily stopped, and when the corresponding height setting button 10c is pressed, the corresponding height setting point is stored in the central processing unit 11. You. As a result, the ram 1 does not rise above the corresponding height set point, and the ram stoke can be set to the minimum stroke according to the size of the workpiece W. Setting means B1 for setting the corresponding height set point; storage means B2 for storing the set corresponding height set point; detecting means B3 for detecting the set corresponding height set point; The change means B4 for changing the height set point is generically referred to as corresponding height set point control means B.

Thereafter, various functions are made to function using the corresponding height set point as a reference point. Next, the setting of the press-fitting work starting point is performed by pressing the operation button 9a and the operation button 9b to lower the ram 1, and at a position where the ram 1 comes into contact with the workpiece W,
Press the press-fitting work start setting button 10d and press the central processing unit 1
The press-fitting work start point is stored in 1 as a position to which a pressing force necessary for press-fitting should be applied. Setting means C1 for setting the press-fitting work start point; storage means C2 for storing the set press-fitting work start point; detecting means C3 for detecting the set press-fitting work start point; Is generally called press-fitting work start point control means C.

Further, the ram 1 is lowered by pressing the operation buttons 9a and 9b, and the ram 1 is temporarily stopped at a press-fitting stop point as an arbitrary position where the pressing of the workpiece W is completed. When the press-fit stop setting button 10e is pressed, the press-fit stop point is stored in the central processing unit 11. The setting means D1 for setting the press-fit stop point as such a set pressure end position, the storage means D2 for storing the set press-fit stop point, and the detecting means D3 for detecting the set press-fit stop point. The changing means D4 for changing the press-fit stop point is collectively referred to as press-fit stop point control means D.

When the ram 1 is lowered to the press-fitting stop point position, the ram 1 is automatically raised to the corresponding height set point and stopped.

The speed of the stroke of the ram 1 between the processing positions described above is stored in the central processing unit 11 so as to descend at a high speed from the corresponding height setting point to the press-fitting work start point, and is temporarily stored at the press-fitting work start point position. The central processing unit 11 is stored so as to stop, and is further lowered from the press-fitting work start point to the press-fitting stop point at a low speed and in a state where a sufficient output necessary for pressurization is possible.
Is stored.

In order to execute the press-fit stop point control means D, a press force control means E for controlling a press force for press-fitting the workpiece W is often required. The pressing force control means E includes setting means E1 for setting the pressing force, storage means E2 for storing the set pressing force, detecting means E3 for detecting the set pressing force, and This is a general term for the changing means E4 to be changed.

When the press-fitting stop point is set, it may be performed through the press-fit length control means. Further, when the set position of the press-fitting stop point is inconvenient, a correction value can be set in the digital switch 10f of the control unit 10 to change the fixed position stop point by a necessary dimension. As a result, the operation setting required for the pressurizing operation is set.

A signal from the central processing unit 11 is digitally converted to a current setting circuit 14 by these stored programs.
Is converted to analog and sent to the motor driver 12,
Current control is performed, and the desired speed and pressure of the ram 1 are adjusted by the current control.

Next, the flowchart shown in FIG. 4 will be described. When started, the ram 1 descends from the corresponding height set point at a specified speed (high speed) in S1 until it confirms the position of the press-fitting work start point, and in S2, determines whether or not the press-fitting work start point is detected by the pressure sensor. Is determined, the pressure is lowered from the position where the press-fitting work start point is detected at S3 with a large torque as a press-fitting condition and a specified press-fitting speed.
At this time, it is determined whether the detected pressure is normal or abnormal in S4,
If the detected pressure is normal, the pressure is further lowered, and it is determined in S5 whether or not the ram 1 is at the lower limit position. When the press-fitting stop point is confirmed, it is determined in S6 whether or not the stop position. If it is the stop position, it stops, the ram 1 rises again to the corresponding height set point position and stops, ending a series of pressing operations.

At S4, it is determined whether the detected pressure is normal or abnormal. If the detected pressure is abnormal, that is, if the detected pressure is out of the predetermined range (too hard or too low), S4 is performed.
At 7, a lamp or an alarm is displayed and an abnormality is displayed on both, and the operation is stopped. Also, when the lower limit position of the ram 1 is not the predetermined position, an error is displayed (see S7) and the operation is stopped. Further, in S6, it is determined whether or not the stop position is reached. If the stop position is not at the predetermined position, that is, if the press-fitting depth is not at the predetermined position, the large torque and the specified press-fit as the press-fitting conditions at the S3 position are again performed. It returns so as to pressurize and descend at the speed.

In step S2, the pressure sensor determines whether or not the press-fitting work is started. If it is detected that the press-fitting work is not the starting point, the pressure sensor is again moved to the lowering condition at the designated speed at the position S1. Return.

[0032]

First, according to the first aspect of the present invention, an electric motor, a motor driver for driving the electric motor, a conversion mechanism for converting a rotational force into a linear motion of a press ram by a screw mechanism, and Set the upper limit position corresponding to the workpiece, store it,
Corresponding height setting control means to detect, press-fit work start point control means to set, store, detect and change the press-fit work start position for applying pressure to the workpiece, and press-fit stop position as set pressure end position , Memory, detection, and change of press-fit stop point control means to detect the press-fit work start position and press-fit stop position for each work. Not to give
In the present invention, a press-fitting work start position control means C for setting, storing, detecting, and changing the press-fitting work start position for applying pressure to the workpiece W is provided. Rise pressure can be set from something close to 0,
The point in contact with the workpiece W is defined as the press-fitting operation start position. Thereby, there is an advantage that destruction or damage of the workpiece W is prevented.

In the present invention, since the press-fit stop point control means D for setting, storing, detecting, and changing the press-fit stop position as the set pressure end position is provided, the pressure is set and set after the start of press-fit. A load larger than the applied pressure was not applied. In other words, the lowering and press-fitting of the ram 1 can be stopped at the position set at the press-fitting stop point, thereby achieving high precision.

According to the second aspect of the present invention, in addition to providing the same effects as those of the first aspect, a pressing force control means for setting, storing, detecting, and changing the pressing force for press-fitting into the workpiece W. Since E is provided, it is possible not to apply a load larger than the desired pressure. In other words, the pressure at the time of pressing should not be higher than appropriate, and the work W
There is an advantage that the press work can be performed without giving an impact load to the workpiece, and the processing can be performed with extremely high precision. Further, in the present invention,
If the detected pressure is out of the predetermined range (if it is too hard or too loose), an error is displayed and the operation is stopped. it can.

[0035]

[Brief description of the drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a detailed block diagram of the present invention.

FIG. 3 is an explanatory view showing a positional relationship of a ram according to the present invention.

FIG. 4 is a flowchart of the present invention.

FIG. 5 is a sectional view of the present invention.

FIG. 6 is a perspective view of the present invention.

[Explanation of symbols]

 B: Corresponding height setting point control means C: Press-in work start point control means D: Press-in stop point control means E: Pressing force control means W: Workpiece 1: Ram 3: Electric motor 12: Motor driver

────────────────────────────────────────────────── ─── Continuing on the front page (51) Int.Cl. ⁷ Identification code FI B30B 15/28 B30B 15/28 K (72) Inventor Shinichi Fukada 3-1-1 Kyobashi, Chuo-ku, Tokyo Snake Eye Sewing Machine Industry (56) References JP-A-2-224898 (JP, A) JP-A-62-259632 (JP, A) JP-A-5-261628 (JP, A) JP-A-61-242796 (JP, A) A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B30B 15/14 B23P 19/02 B30B 1/18 B30B 15/26 B30B 15/28

Claims (2)

(57) [Claims] 1. An electric motor, a motor driver for driving the electric motor, a conversion mechanism for converting a rotational force into a linear motion of a press ram by a screw mechanism, and an upper limit position set corresponding to a workpiece. The corresponding height setting control means for storing and detecting, and the press-fitting work start position for applying pressure to the workpiece are set,
A press-fitting work start point control means for storing, detecting, and changing; and setting, storing, detecting, and setting a press-fitting stop position as a set pressure end position.
And a press-fitting stop point control means for changing, pressure for each work
An electric press characterized by detecting a start-up work start position and a press-fit stop position . 2. The pressing force at the time of press-fitting operation according to claim 1.
Pressure control means for setting, storing, detecting, and changing
The detected pressure is out of the specified range during press-fitting operation with the set pressure.
In the case of (1), the electric press is characterized by displaying an abnormality and stopping .