JP2000042663A - Cam contact surface diagnosing device in transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cam contact surface diagnosing device capable of diagnosing the presence/absence of an abnormality of a cam contact surface by detecting the contact surface pressure between a cam body and a cam roller at a drive part of a transfer device while a press is in operation. SOLUTION: A strain gauge 31 is fitted to a transmission shaft to connect a cam lever fitted with a cam roller in contact with a cam body at a drive part of a transfer device to a feed bar, the detection signal from the strain gauge 31 is inputted in a contact force operation part 23 to obtain the force exerted on the transmission shaft, the contact force of the cam body with the cam roller is obtained based on the exerted force, the curvature of the surface of the cam body is obtained by the angle of rotation of the cam body by a curvature operation part 26, the contact force and the curvature are inputted in a contact surface pressure operation part 27 with specified time intervals to obtain the cam contact surface pressure, and the cam contact surface pressure is compared with the permissible value to judge the presence/absence of an abnormality of the cam contact surface on the real time basis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam contact surface diagnostic device for a transfer device.

[0002]

2. Description of the Related Art Generally, a transfer device of a press machine is provided with moving members such as a feed bar and a lifting rod.
Press-formed products are sequentially transferred for each press position.

[0003] A cam mechanism is used in a drive unit for driving a moving member in this transfer device. Normally, a force acting on a cam body and a cam roller in operation of the transfer device, that is, a contact force, is a theoretical force. The value examined in the analysis is multiplied by a coefficient (safety factor) based on experience (design). However, if a contact force greater than the design is applied, a failure due to fatigue failure occurs on the cam body or cam roller surface. However, the operation becomes impossible, but conventionally, the detection of the fatigue fracture and the like has not been performed.

[0004]

As described above, during the operation of the transfer device, the contact state between the cam body and the cam roller is not detected. Therefore, even if the load increases during the operation, damage is not caused. Since the operation is continued without being noticed until the occurrence, an accident occurs suddenly, and there is a problem that production is hindered.

Accordingly, the present invention provides a method for operating a press machine,
It is an object of the present invention to provide a cam contact surface diagnostic device capable of detecting a contact surface pressure between a cam body and a cam roller in a drive unit of a transfer device and diagnosing whether there is an abnormality in a cam contact surface.

[0006]

According to a first aspect of the present invention, there is provided a cam contact surface diagnostic apparatus for a transfer device, comprising: A strain gauge attached to a transmission shaft connecting a moving member and a cam lever to which a cam roller is attached, which is a detecting device for detecting a contact surface pressure between a driving cam body and a cam roller in a transfer device to be moved to a position. A detection signal from the strain gauge is input at predetermined time intervals to determine a force acting on the transmission shaft and to determine a contact force between the cam body and the cam roller based on the acting force; A rotation angle detector that detects a rotation angle of the cam body, and a curvature calculation unit that calculates a curvature of the cam body surface based on the detection angle from the rotation angle detector. The contact force from the contact force calculation unit and the curvature from the curvature calculation unit are input, and the contact surface pressure calculation unit for obtaining the cam contact surface pressure and the contact surface pressure obtained by the contact surface pressure calculation unit are input. And a comparison operation unit for comparing with the allowable surface pressure.

A cam contact surface diagnostic device in a second transfer device according to the present invention includes a driving cam in a transfer device for holding a workpiece and moving to a pressing position in a press via a moving member. A detecting device for detecting a contact surface pressure with a cam roller, wherein a strain gauge connected to a moving member and attached to a cam lever to which a cam roller is attached, and a detection signal from the strain gauge are input at predetermined time intervals. And the strain detected by the strain gauge and the strain previously determined
A contact force detector for determining a contact force acting on a cam roller from data of an acting force; a rotation angle detector for detecting a rotation angle of the cam body; and a surface of the cam body based on a detection angle from the rotation angle detector. A curvature calculator for calculating the curvature of
The contact force from the contact force detection unit and the curvature from the curvature calculation unit are input, and the contact surface pressure calculation unit for obtaining the cam contact surface pressure, and the contact surface pressure calculated by the contact surface pressure calculation unit are input. And a comparison operation unit for comparing with the allowable surface pressure.

[0008] According to each of the above structures, during the operation of the press, the contact force between the cam body and the cam roller is determined for a predetermined time via the strain gauge attached to the transmission shaft or the strain gauge attached to the cam lever. The contact surface pressure is calculated from this contact force and the curvature of the cam body surface at that time, and compared with the allowable surface pressure, so it is possible to determine in real time whether there is an abnormality in the cam contact surface. it can.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A cam contact surface diagnostic device in a transfer device according to a first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, a cam contact surface diagnostic device according to the first embodiment is a transfer device 2 for sequentially transporting a press-formed product (formed product) by a press machine 1 along a press line. Is to detect the contact surface pressure of the cam mechanism in the drive unit 4 of the moving member 3 such as a feed bar and a lifting rod in order to determine whether there is an abnormality.

First, the drive unit 4 in the transfer device 2 will be described. That is, the driving unit 4 is configured as shown in FIG.
As shown in FIG. 2 and FIG. 2, a cam body 12 mainly rotated by a rotary drive shaft 11 of a rotary drive device disposed at an end of the press machine 1 and having an outer peripheral surface formed into a predetermined curved surface, Cam roller 13 that contacts cam body 12
And a cam lever 14 whose lower end is rotatably supported at its lower end. The cam lever 14 has a biasing member such as a cylinder device (see FIG. 1 (shown in FIG. 1) are connected. An end of a feed bar 3 a as an example of the moving member 3 is connected to an upper end of the cam lever 14 via a transmission shaft 16.

Next, the contact surface pressure between the cam body 12 and the cam roller 13 is detected at predetermined time intervals (at short intervals).
So that the contact surface pressure does not exceed the allowable surface pressure (allowable value)
A contact surface diagnostic device for monitoring in real time will be described.

As shown in FIG. 3, this contact surface diagnostic apparatus has a strain gauge 2 for detecting a force acting on a transmission shaft 16.
1 and the distortion detection signal detected by the distortion meter 21 is A /
A contact force calculating unit that inputs the force via the D converter 22 and calculates a force acting on the transmission shaft 16 based on a predetermined calculation formula and a contact force (pressing force) between the cam body 12 and the cam roller 13 based on the working force 23, a rotation angle detector 24 for detecting the rotation angle of the rotation drive shaft 11 of the cam body 12, and an A / D converter 25 for detecting the angle detected by the rotation angle detector 24.
And a curvature calculator 26 for calculating the curvature of the contact surface of the cam body 12 at that time, and a cam body for inputting the contact force from the contact force calculator 23 and the curvature from the curvature calculator 26. A contact surface pressure calculating unit 27 for calculating the contact surface pressure between the cam 12 and the cam roller 13 is input with the contact surface pressure obtained by the contact surface pressure calculating unit 27, and is compared with a previously input allowable surface pressure. If it is smaller than the allowable surface pressure, a signal of "normal" is output, and if it exceeds the allowable surface pressure,
A comparison / judgment unit 28 that outputs a signal of “abnormal”, and in response to an output signal from the comparison / judgment unit 28, outputs a message to that effect to a display unit 30 such as a monitor. And an output control unit 29 that outputs a stop signal to one control device. Note that the contact force calculation unit 23, the curvature calculation unit 26, the contact surface pressure calculation unit 27, the comparison determination unit 28, and the output control unit 29 are configured by, for example, a personal computer.

By the way, the strain gauge 21 is connected to the transmission shaft 16.
Gauge box 31 having a Wheatstone bridge circuit in which the strain gauge 31 is incorporated, and a bridge box 32
And a dynamic distortion measuring unit 33 that outputs the distortion signal as a voltage signal at predetermined intervals (very short intervals) of the distortion signal taken in from.

In the contact force calculating section 23, first,
The force (W ₁ ) acting on the transmission shaft 16 is determined based on the following equation (1). W ₁ = AEε (1) where A is the cross-sectional area of the transmission shaft, E is the longitudinal elastic modulus of the transmission shaft,
ε is a strain value (voltage value) output from the strain meter 21.

Next, based on W ₁ obtained above, the contact force W acting on the contact portion between the cam body 12 and the cam roller 13 is obtained.
₂ is obtained based on the following equation (2). W ₂ = (L ₁ / L ₂ ) W ₁ (2) where L ₁ is the distance between the transmission shaft and the cam lever fulcrum, L ₂
Is the distance between the cam roller and the cam lever fulcrum.

Further, in the contact surface pressure calculating section 27, the curvature and the contact force calculating section 23 obtained by the curvature calculating section 26 are used.
Is input, and the contact surface pressure is calculated based on the following equation (3).

[0018]

(Equation 1)

Next, the diagnosis operation of the cam contact surface will be described. When the press machine 1 is driven, the moving member 3 such as a feed bar is driven by the drive unit 4 via the transmission shaft 16. At this time, the movement is measured by a strain gauge 31 attached to the transmission shaft 16. The detected strain detection signal is input from the dynamic strain measuring unit 33 to the contact force calculating unit 23 via the A / D converter 22 at predetermined time intervals, and the cam body 12 is determined based on the above equations (1) and (2). And the contact force acting on the cam roller 13 and the cam body 12 at that time.
Is obtained, the contact force and the curvature are substituted into the above equation (3), and the contact surface pressure is obtained at predetermined time intervals, that is, in real time.

The contact surface pressure determined in real time is input to a comparison judging section 28, where it is compared with a preset allowable surface pressure. If the contact surface pressure is lower than the allowable surface pressure, output control is performed. The display unit 3 such as a monitor by the unit 29
A display indicating "normal" is displayed at 0.

On the other hand, when the contact surface pressure exceeds the allowable surface pressure, the output control unit 29 displays an indication of “abnormal” on a display unit 30 such as a monitor and controls the press machine 1. An operation stop signal is output to the device. Thus, during operation of the press machine 1, the transmission shaft 1
6 through a strain gauge 31 attached to the cam body 1.
2 and the cam roller 13 are required to have a contact force,
The contact surface pressure is determined from the contact force and the curvature of the cam body 12 at that time, and is compared with the allowable surface pressure, so that it is possible to diagnose in real time whether the cam contact surface is normal or abnormal. , Therefore, it is possible to prevent a sudden accident due to an increase in load during driving,
It is possible to prevent adverse effects on production due to the stoppage of the press machine.

Next, a cam contact surface diagnosis device in a transfer device according to a second embodiment of the present invention will be described with reference to FIG.
It will be described based on. The difference between the second embodiment and the first embodiment is a portion for obtaining the contact force between the cam body and the cam roller. Therefore, in the second embodiment, attention is paid to this portion. I will explain. In addition, the first
Components having the same functions as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and description thereof is omitted.

That is, in the first embodiment, the strain gauge 31 is attached to the transmission shaft 16 and the contact force calculation unit 23 is operated based on the lever ratio of the cam lever 13.
In the second embodiment, the strain gauge 31 of the strain gauge 21 is directly adhered to the cam lever 13 as shown in FIG. The distortion detection signal obtained from the gauge 31 is
The contact force detecting unit 41 compares the strain data (strain detection signal) from the strain gauge 31 obtained by applying various forces to the cam lever 13 in advance, thereby obtaining the contact force acting on the cam lever 13. Is to ask for. Of course, the contact force detector 41 stores data (strain-acting force data) indicating the relationship between the force applied to the cam lever 13 and the distortion caused by the acting force.

The procedure for obtaining the contact force and the contact surface pressure thereafter and the comparison judgment are the same as those in the first embodiment, and therefore, the description thereof will be omitted. Of course, also in the second embodiment, the same effects as in the first embodiment can be obtained.

[0025]

As described above, according to the structure of the present invention, the contact force between the cam body and the cam roller can be obtained through the strain gauge attached to the transmission shaft or the strain gauge attached to the cam lever. The contact surface pressure is determined from the contact force and the curvature of the cam body surface at that time, and by comparing with the allowable surface pressure, it is possible to diagnose whether the cam contact surface pressure is normal or abnormal during operation of the press machine. Therefore, it is possible to prevent a sudden accident due to an increase in the load during operation, so that it is possible to prevent an adverse effect on production due to the stoppage of the press machine.

[Brief description of the drawings]

FIG. 1 is a front view showing an entire transfer device according to a first embodiment of the present invention.

FIG. 2 is a schematic side view showing a main part of a drive unit in the transfer device according to the first embodiment.

FIG. 3 is a block diagram illustrating a configuration of a cam contact surface diagnosis device in the transfer device according to the first embodiment.

FIG. 4 is a block diagram illustrating a configuration of a cam contact surface diagnosis device in a transfer device according to a second embodiment of the present invention.

[Description of Signs] 1 Press machine 2 Transfer device 3 Moving member 4 Drive unit 11 Rotation drive shaft 12 Cam body 13 Cam roller 14 Cam lever 16 Transmission shaft 21 Strain gauge 23 Contact force calculation unit 24 Rotation angle detector 26 Curvature calculation unit 27 Contact Surface pressure calculation unit 28 Comparison judgment unit 31 Contact force calculation unit 41 Contact force detection unit

Claims (2)

[Claims] 1. A detecting device for detecting a contact surface pressure between a driving cam body and a cam roller in a transfer device for holding an article to be molded and moving it to each press position in a press machine via a moving member, A strain gauge attached to a transmission shaft connecting a moving member and a cam lever with a cam roller attached thereto, and a detection signal from the strain gauge is input to obtain a force acting on the transmission shaft, and based on the acting force, A contact force calculation unit for calculating a contact force between the cam body and the cam roller; a rotation angle detector for detecting a rotation angle of the cam body; and a curvature of the cam body surface based on a detection angle from the rotation angle detector. A curvature calculating unit, a contact surface pressure calculating unit for inputting a contact force from the contact force calculating unit and a curvature from the curvature calculating unit to obtain a cam contact surface pressure; A cam contact surface diagnosis device for a transfer device, comprising: a comparison operation unit for inputting a contact surface pressure obtained by an operation unit and comparing the contact surface pressure with an allowable surface pressure. 2. A detecting device for detecting a contact surface pressure between a driving cam and a cam roller in a transfer device for holding an object to be molded and moving it to each pressing position in a press machine via a moving member, comprising: A strain gauge connected to a member and attached to a cam lever to which a cam roller is attached, a detection signal from the strain gauge is input, and the strain detected by the strain gauge and data of a strain-acting force previously determined. A contact force detector for determining a contact force acting on the cam roller, a rotation angle detector for detecting a rotation angle of the cam body, and a curvature of the cam body surface based on the detection angle from the rotation angle detector. A contact surface pressure calculation for obtaining a cam contact surface pressure by inputting a curvature calculation unit and a contact force from the contact force detection unit and a curvature from the curvature calculation unit. A contact surface pressure calculated by the contact surface pressure calculation unit and a comparison calculation unit for comparing the contact surface pressure with an allowable surface pressure.