JPS5819919B2 - Pre-scanning system is not available. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a safe working method for a press machine, which improves productivity and also reduces the time required for workers to be restrained in order to maintain a safe process.

Safety devices used for safe work methods for conventional press machines include hand-pulling devices, manual removal devices, photocells, fixed barrier guards, etc., but they are defenseless against mold breakage and do not pose any threat to workers. Feeling of restraint, need to remove when changing molds,
Each of them has drawbacks such as incompleteness against disturbances such as oil scrap, and due to work such as deep drawing, recently link mechanisms have been used such that the slide reaches the bottom dead center at a crank angle of about 250°. Presses with a quick-return slide displacement mechanism are becoming popular.

In this case, from the safety point of view of the worker, it is not desirable to shorten the holding time of the safety process, and therefore, the production volume per unit time is lower than the absolute amount needed to wait for the next material to be added. This had the disadvantage that safety measures and production costs were in a contradictory relationship, resulting in expensive technological investment.

The invention solves the above-mentioned drawbacks and is an inexpensive device that shortens the time the workers are tied up and reduces worker fatigue. .

In response to this need, the present invention eliminates the problem by rotating the shielding plate forward and upward when replacing the mold, and during normal work, the slide of the press and the front of the mold are shielded by a transparent shielding plate that moves up and down. The object of the present invention is to provide a safe working method for a press machine that can prevent dangers due to breakage and completely prevent accidents caused by workers putting their hands into the mold.

Referring to a drawing of an apparatus according to an embodiment of the present invention, a bracket 4 is supported and installed via an arm 3 attached to a slide gib 2 of a press 1.

An air cylinder 5 is erected at the center of the bracket 4, and a housing 7 is screwed onto the tip of a rod 6 of the air cylinder 5.

The housing I is provided with an outer spline-shaped guide bar that is spline-fitted to a sleeve 11 that is installed on the housing 7 via bearings 8 and 9 and is fitted onto the bracket 4 via a bearing 10 and has a spline on the inner side. 1
2 and a guide bar 16 that is inserted into the housing 7, fixed and erected via the retaining seat 13 and the screw 14, and fitted to the bushing 15 attached to the bracket 4,
The air cylinder 5 is moved up and down by the movement of the rod 6 of the air cylinder 5 when air is supplied in response to the press start signal.

A solid shaft portion is supported on the housing 7 via bearings 17, 1B at the end of the housing 7 on the installation side of the guide bar 12, and one side of a transparent shielding plate 20 is held on the outer shaft portion of the housing 7. A shaft 19 is provided to which the holding fitting 21 is fixed, and a bevel gear 22 is fitted to the shaft portion on the opposite side.

A bevel gear 23 that meshes with the bevel gear 22 and rotates the guide bar 12 is fitted onto the lower shaft portion of the guide bar 12.

Further, one end of a fixed shaft 24 is inserted into the end of the housing 7 on the side where the guide bar 16 is attached, and the central flange portion of the fixed shaft 24 is fixed to the housing I with a screw 25. The shaft portion on the opposite side of the fixed shaft 240 holds a shielding plate 20') and has serrations on one side.

A retaining metal fitting 26 is pivotally mounted, and a retaining ring 27 having serrations formed on one side that engages with the serrations and screwed onto the outer side by a cover 36 is fitted so as to be slidable in the axial direction via an implant key 28. , the stop ring 27 and a stop plate 29 attached to the shaft end of the fixed shaft 24.

A compression spring 30 is installed between them, and the force of the compression spring 30 always keeps the holding fitting 26 and the stop ring 27 in an engaged state.

Further, in order to prevent the shielding plate 20 from rotating inward from the front side of the mold 31 and the slide 32, taking the holding fitting 26 as an example, a stopper 33 is attached to the housing 7 as shown in FIG. is designed to hit and prevent rotation.

Further, the upper part of the sleeve 11 has a tubular body 3 with a cam 34 attached thereto.
5 is fixed and the shielding plate 20 is rotated forward and upward, the serrations of the holding fitting 26 resist the compression spring 30 and repeatedly disengage from the serrations of the stop ring 27 screwed onto the cover 36. When the hand is released, the shielding plate 20 is engaged again with the force of the compression spring 30 to maintain the opened state, but one of the holding metal fittings 21 is attached to the shaft 1.
The guide bar 12 is rotated through the nine bevel gears 22 and 23, and the sleeve 11 is also rotated, and the protrusion of the cam 34 engages with the detection roller 37a' of the limit switch 37 attached to the bracket 4, and the signal from the limit switch 37 causes the guide bar 12 to rotate. Shut off the press startup circuit and place the press machine in the same state as an emergency stop.

Conversely, if the shielding plate 20 is returned to its original shielding position, the press is returned to a state in which it can be started again.

Next, the safe work method of the present invention will be explained with reference to the safety device of the above embodiment according to the present invention. FIG. 1 shows the case where the press slide displacement is a sine wave, and FIG. 2 shows the case where the press slide is a sine wave. This diagram shows the case of a quick return mechanism, and in normal work, the operator presses the button with both hands and works in the safety stroke, so the holding time t of each safety stroke is
During times 2 and t4, the worker's hands are generally placed on the push button and are not placed inside the mold, but there is a risk that the worker may experience mental fatigue and become unsafe due to the restrained time during this time. .

In this work method, the worker presses the two-handed pushbutton, and when the shielding plate descends faster than the slide and finishes shielding the slide and the front of the mold, which is a short period of descent time N and t3, respectively, the worker releases both hands from the two-handed pushbutton. You can then wait for the next processing material to be inserted.

Also, when you want to take out the material from the mold, open the shielding plate and the press will shut off the starting circuit and stop, allowing you to take out the material easily and safely.After taking out the material, return the shielding plate to its original state. The press can be activated by pressing the two-handed pushbutton again.

Even when replacing the parent mold, the shielding plate rises faster than the slide rises and opens the front of the mold, allowing the mold to be replaced without any hindrance.

Next, to explain the effects of the present invention, as shown in FIG.
Since the work is carried out in the process, safety - process holding time t
During time 2, the worker's hands are generally on the push button, so they are not placed inside the mold.

In the meantime, even if the operator loses his hands due to some kind of accident and attempts to insert his hands into the mold when the machine has stopped, the front of the mold will be shielded if the short time t1 for the shielding plate 20 to come down has already passed. Because of this, you cannot put your hands inside the mold, so there is almost no chance of you putting your hands inside the mold while the slide is descending. Shield plate 2 moves faster than the slide rises.
Since 0 is rising, the workpiece can be taken out without difficulty.

In addition, if it is necessary to open the shielding plate 20 during work, regardless of the timing, the press is kept in an emergency stop state by the engagement of the cam 34 and the limit switch 37 as described above, so that the mold can be It is safe because the press will not start even if you accidentally press the work button while you are putting your hand inside.

Also, as a matter of course, during normal press work, the shielding plate 20 shields the front of the slide 38 and the mold 31, so there is complete protection against mold breakage, scattering of scrap, oil disturbance, etc., and it is also easy to replace the mold. At the same time, even when taking out the material from the mold, there is no need to remove the shielding plate 20, so there is no time loss.

In addition, in the case shown in FIG. 2, compared to the conventional method, if t4 is the time during which both hands are restrained by the conventional worker, and t3 is the time during which both hands are restrained by this method, then the time during which both hands are restrained is t4 - t.
Therefore, since the material can be taken out quickly, there is enough time to take out and put in the next material. Conventionally, the next press start-up is not performed after the time t6 required to take out and put in the material. However, since the press startup time can be advanced by a time T, the production volume may increase by that time T. However, since the time t5 available for taking out and putting in materials is long, there is less wave force on the workers, which is advantageous in terms of safety. be.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the vertical displacement of the shield plate according to the present invention when the press slide displacement curve is a sine wave, and Fig. 2 is a diagram for explaining the vertical displacement of the shield plate according to the present invention when the press slide displacement curve is a sine wave. Figure 3 is a diagram for explaining the temporal difference between the operator's motion and the motion in which the time for restraining both hands is shortened according to the present invention, and FIG. FIG. 4 is a side view, FIG. 5 is an enlarged front sectional view for explaining the structure of the second device, and FIG. 6 is a sectional view taken along line AA in FIG. 1 is a press, 2 is a slide gib, 3 is an arm, 4 is a bracket, 5 is an air cylinder, 6 is a rod, 7 is a housing, 8, 9, 10 are bearings, 11 is a sleeve,
12 is a guide bar, 13 is a stopper, 14 is a screw, 15 is a bush, 16 is a guide bar, 17, 1B is a bearing, 19 is a shaft, 20 is a shielding plate, 21 is a holding metal fitting, 22, 2
3 is a bevel gear, 24 is a fixed shaft, 25 is a screw, 26 is a holding metal fitting, 27 is a stop ring, 28 is a built-in key, 29 is a stop plate,
30 is a compression spring, 31 is a mold, 32 is a slide, 33 is a stopper, 34 is a cam, 35 is a tubular body, 36 is a cover,
37 is a limit switch.

Claims (1)

[Claims] 1. Attach a transparent plastic shielding plate to the front of the press that can be raised and lowered by an air cylinder to shield and open the slide of the press and the front of the mold, and at the same time start the press using a two-handed push button. The above-mentioned shielding plate descends faster than the press slide, shielding the press slide and the front of the mold, and after that, even if you remove both hands, the shielding plate remains in its shielding state, and the slide continues to descend until it reaches the bottom dead center. The shielding plate is also raised at the same time as the slide rises, allowing the slide to rise and finish faster than the slide, reducing the time required for the operator to keep pressing the two-hand control button, and preventing the operator from entering the mold with his/her hand during the descending operation. If insertion is made impossible and the shielding plate is rotated toward the front, it can be fixed in any position and at the same time the press starting circuit is cut off, thereby ensuring ease and safety of inserting and removing the mold. Features a safe work method for high productivity in press machines.