JPS6340263Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a safety device for a press brake. Specifically, the invention is a safety device for a press brake. This relates to a light beam type safety device designed to stop the light beam.

[Conventional technology]

As shown in Fig. 17, the press brake is equipped with a ram a that is movable up and down on the main body A.
A punch b is provided at the bottom of the base body B to face the die c provided on the base body B, and a pair of left and right mounting plates e are provided on the left and right front surfaces of the body A and the base B via brackets d.
e are arranged facing each other, and the worker holds the workpiece in his hand and places it between the pair of mounting plates e and e, facing between punch b and die c, and bends the workpiece with punch b and die c. What it does is known.

In such a press brake, if a part of the worker's body, such as a hand, is present between punch b and die c, and punch b descends with ram a, the hand may be cut off, which is very dangerous. It is.

Therefore, as shown in Fig. 17, a light emitter and a light receiver are arranged facing each other at the front of the work area of the press brake (that is, the front part between punch b and die c), and the A light beam type safety device C is known that stops a press brake when a worker blocks light from the optical axis.

[The problem that the idea aims to solve]

As shown in FIG. 17, when a worker h holds a flat workpiece g in his hand i and bends it into a U-shape in two places using a press brake equipped with such a light-emitting safety device, during the second bending process the bent portion g' of the workpiece g approaches the main body A, causing the hand i of the worker h to get caught between the workpiece g and the main body A, which is extremely dangerous.

Therefore, an object of the present invention is to provide a safety device for a press brake that can prevent a worker's hand from being caught between the workpiece and the main body.

[Means and actions to solve the problem]

A ram a and a die c equipped with a punch b are provided facing each other on a main body A and a base body B that face each other, and by moving the ram a up and down, the workpiece held by the operator's hand is moved between the punch b and the die. In the press brake that is bent by c, when the operator's hand is placed between the light emitter and the light receiver at the front position facing the main body A, the optical axis between the light emitter and the light receiver is The second light emitter/receiver group D, which blocks light and emits a signal to stop the press brake ram a, is installed so that the distance between its optical axis and the main body A is slightly larger than the size of the operator's hand. It is a safety device,
As a result, when an operator holds and bends a workpiece, if the hand approaches the front position of the main body A together with the workpiece, the optical axis can be blocked and the press brake can be stopped. This prevents it from getting caught between the materials.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an overall schematic side view, in which a ram a is provided on the main body A so as to be movable up and down, and a punch b is provided at the bottom of the ram a, facing a die c provided on the base body B.

There are brackets d on the front left and right sides of the main body A and the base B.
A pair of left and right mounting plates e, e are disposed opposite to each other via.

On the pair of left and right mounting plates e, a first emitter/receiver group C similar to the conventional one is located at the front position facing between the punch b and the die c, and a first emitter/receiver group C similar to the conventional one is located at the front position facing the main body A. A second light emitting/receiving device group D is provided.

The first light emitter/receiver group C is provided at a position separated from the punch and die by a safe separation distance L 1 depending on the stop time of the ram a, and is located at a distance of a safe distance L ₁ from the punch and die.
It is constructed as shown in FIG.

In other words, a pair of mounting bodies 2 and 3 are provided on the pair of left and right mounting plates e and e, one mounting body 2 is provided with a light emitting diode 4 serving as a light emitter at a predetermined interval, and the other mounting body 3 is provided with light receiving diodes 5 that serve as light emitters at predetermined intervals, and the width t ₁ of the optical axis 6 is 1/1 of the size of the smallest part of the body (hereinafter referred to as the "minimum part"). 2, that is, the size is 1/2 of the finger of a hand, and is generally about 5 mm, and the pitch t ₂ between the optical axes 6 is 1/2 the size of the smallest part.

When one optical axis 6 is blocked, a stop signal is not output to the press brake, and when two or more optical axes 6 are blocked, a stop signal is output to the press brake.

Then, when the amount of light on the optical axis 6 becomes 1/2 or less, a signal indicating that the optical axis 6 is blocked is output.

However, as shown in Figure 3, if only one optical axis is blocked due to the position of the shade, the size t ₁ /
This is the case of object A ₃ with size 2 x t ₁ from object A 1 in 2. In particular _, in the case of size t ₁ , only one optical axis is blocked, or the optical axis is not blocked at all, so press No stop signal is output to the brake. In addition, when two or more optical axes are blocked, it is the case of an object A ₂ with a size of t ₁ or more, and especially in the case of an object A ₃ with a size of 2 × t ₁ or more, two optical axes are definitely blocked, and a stop signal is sent to the press brake. is output.

Therefore, 1/ of the size of the smallest part of the body
2. In other words, even if an object smaller than the width t ₁ of the optical axis 6 is fed into the press body beyond the position where it blocks light from the optical axis 6, the press brake will not stop, and the material with the width t ₁ or less of the optical axis 6 will not be stopped. It can be supplied into the press brake body, and when the smallest part of the body (finger of the hand) faces, two or more optical axes are blocked, a stop signal is output to the press brake, and the press brake stops safely. It is.

FIG. 4 is a control circuit diagram thereof, in which the output of each photoreceiver 5 is input to the amplifier 7, the output of each amplifier 7 is input to the first OR gate ₈₁ , and the output of the remaining amplifiers 7' is input to the second OR gate 8 ₂ , the outputs of the first and second OR gates 8 ₁ and 8 ₂ are input to the AND gate 9 , and the output is connected to the press emergency stop switch 10 .

Because of this, when one optical axis 6 is blocked and one optical receiver 5 ₁ is turned OFF, the output of the first OR gate 8 ₁ becomes (+), but the output of the other optical receiver 5 becomes (+).
Since the output of the second OR gate ₈₂ is (-) when ON, the AND gate 9 does not output and the contact 10a of the emergency stop switch 10 remains closed and does not stop.

When two adjacent optical axes 6 are blocked and the two light receivers 5 ₁ and 5 ₂ are turned OFF, the outputs of the first and second OR gates 8 ₁ and 8 ₂ become (+), and the AND gate 9
The output of also becomes (+), the contact 10a opens, and the press brake is stopped.

The second light emitting/receiving device group D is located above the first light emitting/receiving device group C, and is provided at a front position facing the main body A at a predetermined distance L ₂ (L ₂ >L ₁ ). The distance _L2 is, as shown in Fig. 5, when the operator's hand A stops the ram A that blocks the optical axis.
A distance that has a gap L′ ₂ sufficient for the hand to enter between the workpiece A and the main body A when it protrudes to the side,
In other words, the distance between the main body A and the optical axis is set to be slightly larger than the operator's hand.

In other words, when the worker holds the bent part of the workpiece B, which has been bent approximately 90 degrees at one end, and bends the other end, the punch B descends to perform the bending process. As shown in Figure 5, the workpiece A moves upward sequentially and the worker's hand is sandwiched between the main body A and the workpiece B, so the worker's hand blocks the optical axis before touching the ram. During the time difference until ram a stops, ram a descends and bends workpiece B, and the worker's hand moves to the main body A side together with workpiece R, and the worker's hand moves to main body A. I am careful not to touch it.

The second light emitter/receiver group D is shown in FIGS.
It is constructed as shown in FIG.

In other words, a pair of mounting bodies 12 and 13 are provided on the pair of left and right mounting plates e and e, one mounting body 12 is provided with a light emitting diode 14 serving as a light emitter at a predetermined interval, and the other mounting body 13, light receiving diodes 15 serving as light receivers are provided at predetermined intervals, and the width _t3 of the optical axis 16 is 1/1 of the size of the smallest part of the body (hereinafter referred to as the "minimum part"). 2,
In other words, it is half the size of a finger, generally about 5 mm, and the pitch _t4 between the optical axes 16 is the size of the smallest part.

When one optical axis 16 is blocked, a stop signal for the press brake is not output, but when two or more optical axes 16 are blocked, a stop signal is output for the press brake.

Then, when the amount of light on the optical axis 16 becomes 1/2 or less, a signal indicating that the optical axis 16 is blocked is output.

However, as shown in Figure 7, for example, the size
Even if an object A ₁ of t ₃ /2, an object A ₂ of size t ₃ , and an object A ₃ of size t ₄ or less face the main body A side from the position where the optical axis 6 is blocked, the two optical axes 6 are blocked. Therefore, no stop signal is output to the press brake.

Therefore, objects with a size of 10 mm or less, that is,
Even if an object smaller than the smallest part comes closer to the main body A than the position that blocks the optical axis 16, the press brake will not stop, and will bend the thin material and remove the object from the main body A.
When an object larger than _2t4 (in other words, a worker's hand) comes in front of the machine, two or more optical axes are reliably blocked, a stop signal is output to the press brake, and the press brake stops. Processed material and main body A
It is safe because the worker's hands will not be caught between the two.

FIG. 8 is a control circuit diagram, in which the output of each photoreceiver 15 is input to the amplifier 17, the output of each amplifier 17 is input to the first OR gate ₁₈₁ ,
The output of the remaining amplifier 17' is connected to the second OR gate 18 ₂
The outputs of the first and second OR gates 18 ₁ and 18 ₂ are input to the AND gate 19 , and the output is connected to the press emergency stop switch 20 .

Because of this, when one optical axis 16 is blocked and one optical receiver 15 ₁ is turned OFF, the output of the first OR gate 18 1 becomes (+), but when the other optical receiver 15 is ON, the output of the second OR gate 18 ₁ becomes (+). Since the output of the OR gate ₁₈₂ is (-), the AND gate 19 does not output and the contact 20a of the emergency stop switch 20 remains closed and does not stop.

When the two adjacent optical axes 16 are blocked and the two light receivers 15 ₁ and 15 ₂ are turned off, the outputs of the first and second OR gates 18 ₁ and 18 ₂ become (+), and the output of the AND gate 19 also becomes (+) and the contact 2
0a is open to stop the press brake.

In the embodiment, as shown in FIG. 1, third, fourth, and fifth light emitting/receiving device groups E and FG are provided.

The third light emitter/receiver group E is provided at a position a predetermined distance L ₃ away from the punch b in the front portion facing between the punch b and _the die c, and
is the safe separation distance determined by the maximum arm length of the worker + the ram stop time. In other words, when bending a long board into a box shape, the optical axis of the first light emitter/receiver group C is blocked by the long board bent into a box shape and the ram a stops. To do this, the first emitter/receiver group C is deactivated and the third emitter/receiver group E is activated, and the worker stands in front of the third emitter/receiver group E and works with his arm extended toward the ram A. In addition, it is installed in such a position that even if the worker extends his arm to the maximum extent, he cannot reach the ram a, but if the worker bends at the waist and extends his arm, he can reach the ram a. The third light emitting/receiving device group E is constructed as follows.

That is, as shown in FIG. 9, a pair of mounting bodies 22 and 23 are provided on a pair of left and right mounting plates e and e,
On one mounting body 22, light emitting diodes 24 serving as light emitters are provided at predetermined intervals, and on the other mounting body 23, light receiving diodes 25 serving as light receivers are provided at predetermined intervals. 26 width t ₅
is about 1/2 the size of the smallest part of the body, generally about 5 mm, and the distance between the optical axes ₂₆ is the size of the arm of the body, generally about 100 mm. .

When one optical axis 26 is blocked, a press brake stop signal is not output, but when two or more optical axes 26 are blocked, a press brake stop signal is output.

Then, when the amount of light on the optical axis 26 becomes 1/2 or less, a signal indicating that the optical axis 26 is blocked is output.

Therefore, as shown in Fig. 10, for example, 25 mm
Object A ₁ , Object A ₂ of 50 mm, Object A ₃ of 100 mm or less
Even if the optical axis 26 is located between the punch b and the die c (that is, the working area) from the position where the optical axis 26 is blocked, the two optical axes 26 are not blocked, so no stop signal is output to the press brake.

Therefore, objects with a size of 100 mm or less, that is,
Even if the worker's arm blocks the light from the optical axis 26, the press brake does not stop, allowing operations such as carrying in and out of workpieces into the work area. At this time, it is safe because the arm does not reach the work area.

In addition, if an object with a size of 2×t ₆ or more, that is, the body is bent so that the torso faces the optical axis 26, two or more optical axes will be definitely blocked, and a stop signal will be output to the press brake, causing the press brake to stop. When the machine stops and you bend your body and extend your arms, you can reach the work area, but it is safe because the press brake stops.

FIG. 11 is a control circuit diagram, in which the output of each photoreceiver 25 is input to the amplifier 27, the output of each amplifier 27 is input to the first OR gate ₂₈₁ ,
The output of the remaining amplifier 27' is connected to the second OR gate 28 ₂
The outputs of the first and second OR gates 28 ₁ and 28 ₂ are input to an AND gate 29 , and the output is connected to a press emergency stop switch 30 .

Because of this, when one optical axis 26 is blocked and one optical receiver 25 ₁ is turned OFF, the output of the first OR gate 28 1 becomes (+), but when the other optical receiver 25 is ON, the output of the second OR gate 28 ₁ becomes (+). Since the output of the OR gate ₂₈₂ is (-), the AND gate 29 does not output and the contact 30a of the emergency stop switch 30 remains closed and does not stop.

When the two adjacent optical axes 26 are blocked and the two light receivers 25 ₁ and 25 ₂ are turned off, the outputs of the first and second OR gates 28 ₁ and 28 ₂ become (+), and the output of the AND gate 29 also becomes (+) and the contact 3
0a is open to stop the press brake.

The fourth light emitter/receiver group F is arranged horizontally in the front part facing the base body B of the press brake below the die c, and its height _H1 is the height of the worker's waist (approximately 700 mm to 1000 mm). ), the height is such that it does not affect the insertion of the processed material, and it is installed between the first light emitter/receiver group C and the third light emitter/receiver group E.

That is, in the case of work in which the processed material B blocks the light beam of the first light emitting/receiving group C as described above, the first light emitting/receiving group C is deactivated as described above, and the third light emitting/receiving group C is turned off. The worker works while standing in front of the device group E, but depending on the length of the material to be processed, the worker may stand in a position that blocks the optical axis of the third emitter/receiver group E. There are cases where it is efficient, and in this case, the ram a is stopped by the third light emitter/receiver group E, so it is necessary to make the third light emitter/receiver group E inoperable together with the first light emitter/receiver group C. The worker is ram a
A fourth emitter/receiver group F is installed to detect the approach of the ram a and stop the ram a.
The light emitter/receiver group F is constructed as follows.

That is, as shown in FIG. 12, a pair of mounting bodies 32 and 33 are provided on the left and right mounting plates e and e in a horizontal direction, and one of the mounting bodies 32 has a light emitting diode 34 serving as a light emitter. light emitting diodes 35 serving as light receivers are provided at predetermined intervals on the other mounting body 33;
The pitch t ₈ between the optical axes 36 is the size of the body, generally about 200 mm.

A stop signal is output to the press brake when one optical axis 36 is blocked.

Because of this, if a worker enters the front of the press brake, the press brake can be immediately stopped and it is safe.

The fifth light emitter/receiver group G is disposed horizontally at a position below the die c and further away from the fourth light emitter/receiver group F at the front position facing the base body B, and the installation height _H2 is The maximum distance _L4 from the base body B is the maximum length when the body is bent and the arms are horizontal, plus the safe separation distance due to the ram stop time. A stop signal is output to the press brake when a worker enters a position away from the base body B by the distance _L4 .

That is, in the work described above for the fourth light emitter/receiver group F, there are cases where the length of the workpiece becomes longer and the workpiece blocks light from the optical axis of the third light emitter/receiver group E. In this case, The third emitter/receiver group E
Since the ram a stops, the third emitter/receiver group E
It is necessary to make it inoperable together with the first light emitter/receiver group C, and since the processed material is long, the fourth light emitter/receiver group F
Not only does the worker not be able to enter until the fourth emitter/receiver group F makes it impossible to ensure safety, but depending on the worker's standing position, when the worker's body is bent and his arms are horizontal, his hands may reach the ram a. Because it may reach
A fifth emitter/receiver group G is used to detect the operator and stop the ram a when the operator enters the above-mentioned position.
is installed, and this fifth light emitter/receiver group G is constructed as follows.

In other words, a pair of mounting bodies 42 and 43 are provided on the pair of left and right mounting plates e and e, one mounting body 42 is provided with a light emitting diode 44 serving as a light emitting device at a predetermined interval, and the other mounting body 43, light emitting diodes 45 serving as light emitters are provided at predetermined intervals, and the pitch _t10 between the optical axes 46 is generally about 200 mm, which is the size of the body.

A press brake stop signal is output when one optical axis 46 is blocked.

Because of this, when a worker approaches the press brake to a position where his/her hands are facing into the work area when the worker bends at the waist and extends his/her arms horizontally, the press brake is stopped and it is safe.

Further, the first to fifth switches C', D', E', F′, G′ are the 14th
As shown in the figure, it is connected to the sudden stop circuit H.

In other words, the fifth and fourth switches G' and F' are in series, the fifth and third switches G' and E' are in parallel, and the fourth
It is in series with switch F', and the first and second switches
C′ and D′ are in series.

Therefore, if two or more of the optical axes of the first and second light emitting/receiving device groups C and D are interrupted, the press brake will suddenly stop.

Therefore, as shown in Fig. 5, when the workpiece is bent twice and the worker's hand approaches the main body A, the press brake stops and the hand becomes stuck between the workpiece A and the workpiece. It can prevent you from getting caught.

Further, if the optical axes of the fifth and fourth light emitting/receiving device groups G and F are respectively shielded from light, the press brake will suddenly stop.

Therefore, if there is a worker within the distance _L4 , the press brake will stop.

In addition, when bending the processed material into an upward U-shaped box shape as shown in Fig. 15, the thickness is x mm and the length is y mm.
Then, as shown in FIG.
Since two or more optical axes are blocked, in this case it is not possible to work unless the state is in the non-detection state.
It is safe because the light emitter/receiver group E operates and thereby the press brake can be stopped.

Also, if the thickness is x mm and the length is y′mm, the first and third
Since two or more optical axes of the light emitter/receiver groups C and E are blocked, they cannot be operated unless they are in a non-detection state.
It is safe because the fourth and fifth light emitter/receiver groups F and G detect the approach of a worker to the press brake and suddenly stop the press brake.

In other words, the first, second, third, fourth, and fifth light emitting/receiving device groups C, D, E, F, and G may be inoperative or activated during the work, and may also be operated as dedicated machines. In such cases, it is sufficient to install only a group of light emitters and receivers suitable for the work.

[Effect of idea]

When an operator bends a workpiece by holding it in his hand, when his hand approaches the front position of the main body A with the workpiece, the optical axis of the second light emitting/receiving group D is blocked and the press brake is stopped. It is safe because the worker's hand can be prevented from being caught between the material and the main body.

[Brief explanation of the drawing]

Figure 1 is an overall view showing an embodiment of the present invention;
Figures 6, 9, 12, and 13 are
〜Explanatory diagram of the fifth light emitting and receiving group A circuit diagram of the 1st to 3rd light emitter/receiver groups, Fig. 5 is an explanatory diagram of the operation of the 2nd light emitter/receiver group, Fig. 14 is a switch circuit diagram of the 1st to 5th light emitter/receiver groups, and Fig. 15 is a processing diagram. FIG. 16 is a perspective view of the material, FIG. 16 is an explanatory diagram of its operation, and FIG. 17 is an explanatory diagram of a conventional example. A is the main body, B is the base, a is the ram, b is the punch,
c is the die, and D is the second light emitting/receiving group.

Claims (1)

[Scope of utility model registration request] A ram a and a die c equipped with a punch b are provided facing each other on a main body A and a base body B that face each other, and by moving the ram a up and down, the workpiece held by the operator's hand is moved between the punch b and the die. In a press brake that performs bending by c, when the operator's hand approaches the front part between the punch b and the die c, there is a gap between the emitter and the receiver. A first light emitter/receiver group C is provided which blocks the optical axis of the press brake and issues a signal to stop the ram a of the press brake. When the hand approaches, the second light emitting/receiving group D blocks the optical axis between the light emitter and the light receiver and issues a signal to stop the press brake ram a.
A safety device for a press brake, characterized in that the distance between the optical axis and the main body A is slightly larger than the size of a worker's hand.