Safety control devices for adjacent workstations

Abstract

A safety control device for adjacent workstations. The safety control device includes a first sensing element and a first controller, provided for a first passageway of a first workstation. The first sensing element is used to sense a workpiece passing through the first passageway, and the first controller is used to control the first sensing element; and a second sensing element and a second controller, provided for a second passageway of a second workstation. The second sensing element is used to sense a workpiece passing through the second passageway, and the second controller is used to control the second sensing element. The first controller includes at least a first output normally closed contact, and the second controller includes at least a second output normally closed contact, with the first and second output normally closed contacts connected in parallel; or the first controller includes at least a first output normally open contact, and the second controller includes at least a second output normally open contact, with the first and second output normally open contacts connected in series. According to the present invention, safety and reliability can be ensured, and costs can be reduced.

Description

Technical Field

[0001] The present invention relates to safety control of a workstation, and in particular to a safety control device for adjacent workstations. Background Art

[0002] In modern industrial automated assembly line production, different operations are typically performed sequentially at different workstations. For workpieces with demanding machining requirements, some operations must be performed in largely separate spaces, each forming an independent workstation. To facilitate the transfer of workpieces between adjacent workstations, each workstation is equipped with a passageway. Current safety standards mandate that each passageway be equipped with a lift gate. Figure 1 Schematically shows adjacent workstations provided with lift doors according to the prior art. Figure 1 As shown, the adjacent first workstation 1 and second workstation 3 are respectively provided with a first channel opening 5 and a second channel opening 7, a first lifting gate 9 is provided for the first channel opening 5 of the first workstation 1, and a second lifting gate 11 is provided for the second channel opening 7 of the second workstation 3. Two substantially parallel conveyor belts 13 extend from the first workstation 1 to the second workstation 3 through the first channel opening 5 and the second channel opening 7, and a retractable stopper 15 is provided between the two substantially parallel conveyor belts 13. When a workpiece 17 to be processed moves to a predetermined position in the first workstation 1, the retractable stopper 15 extends to stop the workpiece 17 to be processed so that it can be processed. After the workpiece 17 to be processed has been processed, the retractable stopper 15 retracts so that the workpiece 17 to be processed moves through the first channel opening 5 and the second channel opening 7 to the second workstation 3 for the next step of processing. According to this prior art, workpieces 17 to be processed can only be moved from first workstation 1 to second workstation 3 when first and second lift doors 9, 11 are simultaneously raised to open first and second passage openings 5, 7. However, safety regulations require that all processing operations in first and second workstations 1, 3 must be stopped when first and second lift doors 9, 11 are simultaneously raised. To minimize the time processing operations are stopped, the lifting of first and second lift doors 9, 11 must be precisely controlled, requiring additional control mechanisms and special programming, resulting in a significant increase in cost.

[0003] Therefore, there is a need for an improved safety control device for adjacent workstations. Summary of the Invention

[0004] One object of the present invention is to overcome at least one of the defects in the above-mentioned prior art and to provide a safety control device for adjacent workstations. This safety control device for adjacent workstations is not only simple in structure and reliable, but also easy to operate and does not require a dedicated control program to be designed for it. Therefore, it can significantly reduce costs while ensuring safety and reliability.

[0005] According to one aspect of the present invention, a safety control device for adjacent workstations is provided, wherein a first workstation among the adjacent workstations has a first access opening, and a second workstation among the adjacent workstations has a second access opening disposed proximate to the first access opening, so that a workpiece to be processed can be moved from the first workstation to the second workstation through the first access opening and the second access opening, the safety control device comprising:

[0006] a first sensing element and a first controller provided for the first passage opening, wherein the first sensing element is used to sense the workpiece passing through the first passage opening in a non-contact manner, and the first controller is used to control the first sensing element; and

[0007] a second sensing element and a second controller provided for the second passage opening, the second sensing element being used for non-contact sensing of the workpiece passing through the second passage opening, and the second controller being used for controlling the second sensing element;

[0008] Wherein, the first controller includes at least a first output normally closed contact, the second controller includes at least a second output normally closed contact, and the first output normally closed contact and the second output normally closed contact are connected in parallel; or

[0009] The first controller includes at least a first output normally open contact, and the second controller includes at least a second output normally open contact. The first output normally open contact and the second output normally open contact are connected in series.

[0010] Optionally, the first sensing element is a first grating body including a first emitter and a first receiver arranged corresponding to the first emitter, the first controller is a first grating controller, and the first emitter and the first receiver are respectively connected to the first grating controller.

[0011] Optionally, the second sensing element is a second grating body including a second emitter and a second receiver arranged corresponding to the second emitter, the second controller is a second grating controller, and the second emitter and the second receiver are respectively connected to the second grating controller.

[0012] Optionally, the first sensing element is a first proximity sensor, and the first proximity sensor is connected to the first controller.

[0013] Optionally, the second sensing element is a second proximity sensor, and the second proximity sensor is connected to the second controller.

[0014] Optionally, the first sensing element is a first grating body including a first emitter and a first receiver arranged corresponding to the first emitter, the first controller is a first grating controller, and the first emitter and the first receiver are respectively connected to the first grating controller; and the second sensing element is a second grating body including a second emitter and a second receiver arranged corresponding to the second emitter, the second controller is a second grating controller, and the second emitter and the second receiver are respectively connected to the second grating controller.

[0015] Optionally, the first grating body and the second grating body are arranged so that a distance between a first grating emitted from the first emitter to the first receiver and a second grating emitted from the second emitter to the second receiver is greater than a length of the workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematically shows adjacent workstations provided with lift doors according to the prior art;

[0017] Figure 2 Schematically shows adjacent workstations provided with a safety control device according to the present invention;

[0018] Figure 3 Schematically shows the structure of the grating assembly according to the present invention;

[0019] Figure 4 The working principle of the safety control device according to the present invention is schematically shown;

[0020] Figure 5 Schematically shows the working state of the safety control device according to the present invention when a workpiece to be processed passes through the grating generated by the first grating body;

[0021] Figure 6 The working state of the safety control device according to the present invention is schematically shown when a workpiece to be processed passes through the grating generated by the second grating body;

[0022] Figure 7 Schematically shows the working state of the safety control device according to the present invention when a foreign object passes through the gratings generated by the first grating body and the second grating body at the same time; and

[0023] Figure 8 The working principle of another embodiment of the safety control device according to the present invention is schematically shown. DETAILED DESCRIPTION

[0024] The preferred embodiments of the present invention are described in detail below with reference to examples. It should be understood by those skilled in the art that these exemplary embodiments are not intended to limit the present invention in any way.

[0025] Figure 2 Schematically shows adjacent workstations provided with a safety control device according to the present invention. Figure 2 As shown, the adjacent first workstation 1 and second workstation 3 are respectively provided with a first channel opening 5 and a second channel opening 7. Two conveyor belts 13 extending substantially in parallel extend from the first workstation 1 to the second workstation 3 through the first channel opening 5 and the second channel opening 7, and a retractable stopper 15 is provided between the two conveyor belts 13 extending substantially in parallel. When the workpiece 17 to be processed moves to a predetermined position in the first workstation 1, the retractable stopper 15 extends so that the workpiece 17 to be processed stops moving so that it can be processed. After the workpiece 17 to be processed has been processed, the retractable stopper 15 retracts so that the workpiece 17 to be processed moves through the first channel opening 5 and the second channel opening 7 to the second workstation 3 for the next step of processing. According to the present invention, a first grating assembly 19 is provided for the first channel opening 5 of the first workstation 1, and a second grating assembly 21 is provided for the second channel opening 7 of the second workstation 3. The first grating assembly 19 includes a first grating body 23 and a first grating controller 25 (shown in Figure 3 Similarly, the second grating assembly 21 includes a second grating body 27 and a second grating controller (not shown in the figure).

[0026] Figure 3 The structure of the grating assembly according to the present invention is schematically shown. The first grating assembly 19 and the second grating assembly 21 have the same structure. The structure of the grating assembly is described below by taking the first grating assembly 19 as an example. Figure 3As shown, the first grating body 23 of the first grating assembly 19 includes a first emitter 23a and a first receiver 23b corresponding to the first emitter 23a. The first emitter 23a and the first receiver 23b are respectively connected to a first grating controller 25 of the first grating assembly 19. The first grating controller 25 is used to control the first emitter 23a and the first receiver 23b, and includes a first output normally closed contact K1 and a first output normally open contact K2. When the grating transmitted from the first emitter 23a of the first grating body 23 to the first receiver 23b of the first grating body 23 is not blocked, that is, when no object passes through the grating, the first output normally closed contact K1 of the first grating controller 25 is in a closed state, and the first output normally open contact K2 of the first grating controller 25 is in an open state. When the grating emitted from the first transmitter 23a of the first grating body 23 to the first receiver 23b of the first grating body 23 is blocked, that is, when an object passes through the grating, the first output normally closed contact K1 of the first grating controller 25 is in an open state, and the first output normally open contact K2 of the first grating controller 25 is in a closed state.

[0027] Figure 4 The working principle of the safety control device according to the present invention is schematically shown. Figure 4 As shown, the first output normally closed contact K1 of the first light barrier controller 25 and the second output normally closed contact K1' of the second light barrier controller are connected in parallel, and then the parallel-connected first output normally closed contact K1 and second output normally closed contact K1' are connected in series in the safety circuit (not shown) of the first workstation 1 and the second workstation 3. When either or both of the first output normally closed contact K1 and the second output normally closed contact K1' are in a closed state, the safety circuit is in a normal working state; when the first output normally closed contact K1 and the second output normally closed contact K1' are both in an open state, the safety circuit is in a disconnected (abnormal) state.

[0028] Figure 5 The schematic diagram shows the working state of the safety control device according to the present invention when the workpiece to be processed passes through the grating generated by the first grating body. Figure 5 As shown, when the workpiece 17 to be processed passes through the first grating 23c emitted from the first transmitter 23a of the first grating body 23 to the first receiver 23b of the first grating body 23, the first grating 23c is blocked, and the first output normally closed contact K1 of the first grating controller 25 is opened, but at this time the second grating 27c emitted from the second transmitter 27a of the second grating body 27 to the second receiver 27b of the second grating body 27 is not blocked, and the second output normally closed contact K1' of the second grating controller remains closed, and the safety circuits of the first workstation 1 and the second workstation 3 are in a closed (normal working) state.

[0029] Figure 6 The schematic diagram shows the working state of the safety control device according to the present invention when the workpiece to be processed passes through the grating generated by the second grating body. Figure 6 As shown, when the workpiece 17 to be processed passes through the second grating 27c emitted from the second emitter 27a of the second grating body 27 to the second receiver 27b of the second grating body 27, the second grating 27c is blocked, and the second output normally closed contact K1' of the second grating controller is opened, but at this time the first grating 23c emitted from the first emitter 23a of the first grating body 23 to the first receiver 23b of the first grating body 23 is no longer blocked, and the first output normally closed contact K1 of the first grating controller 25 returns to the closed state, and the safety circuits of the first workstation 1 and the second workstation 3 are in a closed (normal working) state.

[0030] Figure 7 The schematic diagram shows the working state of the safety control device according to the present invention when a foreign object passes through the gratings generated by the first grating body and the second grating body at the same time. Figure 7 As shown, when a foreign object F, such as an operator's arm, simultaneously passes through the first grating 23c, which is emitted from the first transmitter 23a of the first grating body 23 to the first receiver 23b of the first grating body 23, and the second grating 27c, which is emitted from the second transmitter 27a of the second grating body 27 to the second receiver 27b of the second grating body 27, both the first grating 23c and the second grating 27c are blocked, and the first output normally closed contact K1 of the first grating controller 25 and the second output normally closed contact K1' of the second grating controller are simultaneously opened, and the safety circuits of the first workstation 1 and the second workstation 3 are in the open (abnormal) state. To allow the workpiece 17 to be processed to pass normally through the first and second passage openings 5 ​​and 7 without simultaneously blocking the first and second gratings 23c and 27c, the first and second grating bodies 23 and 27 are configured so that the distance between the first and second gratings 23c and 27c they generate is greater than the length of the workpiece 17 to be processed. In this way, when the workpiece 17 to be processed is moved from the first workstation 1 to the second workstation 2 through the first channel opening 5 and the second channel opening 7, it will not cause any interruption to the processing operations in the first workstation 1 and the second workstation 2, which can significantly improve the processing efficiency of the workpiece.

[0031] In the preferred embodiment described above, the first output normally closed contact of the first light barrier controller and the second output normally closed contact of the second light barrier controller are utilized. In this case, when an abnormal situation occurs, the first output normally closed contact of the first light barrier controller and the second output normally closed contact of the second light barrier controller open simultaneously, causing the safety circuits of the first and second workstations to open, thereby triggering the suspension of processing operations in the first and second workstations.

[0032] However, it should be understood that the first output normally open contact of the first photogate controller and the second output normally open contact of the second photogate controller may also be utilized. Figure 8 The working principle of another embodiment of the safety control device according to the present invention is schematically shown. Figure 8 As shown, the first output normally open contact K2 of the first light barrier controller and the second output normally open contact K2' of the second light barrier controller are connected in series. Subsequently, the series-connected first output normally open contact K2 and second output normally open contact K2' are connected in series to a safety circuit (not shown) of the first workstation 1 and the second workstation 3. When either or both of the first output normally open contact K2 and the second output normally open contact K2' are in an open state, the safety circuit is in a normal operating state. When the first output normally open contact K2 and the second output normally open contact K2' are simultaneously closed, the safety circuit is in an on (closed) state, thereby triggering the cessation of processing operations in the first and second workstations.

[0033] While the preferred embodiment of the present invention has been described above in conjunction with a grating assembly, it should be understood that other non-contact sensing elements, such as two proximity sensors, can be used in place of the two grating bodies, or that a single grating body and a single proximity sensor can also be used. Furthermore, while the preferred embodiment depicts the workpieces being processed being transported between the two workstations via a conveyor belt, it should be understood that other methods of transporting the workpieces between the two workstations are also possible.

[0034] Compared to mechanical lift gates, the safety control device for adjacent workstations according to the present invention is not only simple in structure and highly reliable, but also easy to operate and requires no separate control program. Therefore, it significantly reduces costs while ensuring safety and reliability. Furthermore, by controlling the distance between the formed light barriers, any interruption to processing operations in adjacent workstations can be avoided, significantly improving workpiece processing efficiency.

[0035] Although the present invention has been described in detail in conjunction with the preferred embodiments of the present invention, it should be understood that such detailed description is only used to explain the present invention and does not constitute a limitation of the present invention. The scope of the present invention is determined by the technical solutions defined in the claims.

Claims

1. A safety control device for adjacent workstations, wherein a first workstation among the adjacent workstations has a first access opening, and a second workstation among the adjacent workstations has a second access opening disposed proximate to the first access opening, so that a workpiece to be processed can be moved from the first workstation to the second workstation through the first and second access openings, the safety control device comprising: a first sensing element and a first controller provided for the first passage opening, wherein the first sensing element is used for non-contact sensing of the workpiece passing through the first passage opening, and the first controller is used for controlling the first sensing element; as well as a second sensing element and a second controller provided for the second passage opening, the second sensing element being used to non-contactly sense the workpiece passing through the second passage opening, the second controller being used to control the second sensing element, the first sensing element and the second sensing element being arranged such that a distance from the first sensing element to the second sensing element is greater than a length of the workpiece; The first controller includes at least a first output normally closed contact (K1), and the second controller includes at least a second output normally closed contact (K1'). The first output normally closed contact (K1) and the second output normally closed contact (K1') are connected in parallel. The first output normally closed contact (K1) and the second output normally closed contact (K1') connected in parallel can be connected in series in the safety circuit of the first workstation and the second workstation. When either one or both of the first output normally closed contact and the second output normally closed contact are in a closed state, the safety circuit is in a normal working state. When the first output normally closed contact and the second output normally closed contact are in an open state at the same time, the safety circuit is in an open state, thereby triggering the processing operation in the first workstation and the second workstation to stop. or The first controller includes at least a first output normally open contact (K2), and the second controller includes at least a second output normally open contact (K2'). The first output normally open contact (K2) and the second output normally open contact (K2') are connected in series. The first output normally open contact and the second output normally open contact connected in series can be connected in series in the safety circuit of the first workstation and the second workstation. When either one or both of the first output normally open contact and the second output normally open contact are in an open state, the safety circuit is in a normal working state; when the first output normally open contact and the second output normally open contact are in a closed state at the same time, the safety circuit is in a closed state, thereby triggering the processing operation in the first workstation and the second workstation to stop.

2. The safety control device for adjacent workstations according to claim 1, characterized in that: The first sensing element is a first grating body (23) including a first emitter (23a) and a first receiver (23b) arranged corresponding to the first emitter (23a); the first controller is a first grating controller (25); the first emitter (23a) and the first receiver (23b) are respectively connected to the first grating controller (25).

3. The safety control device for adjacent workstations according to claim 1, characterized in that: The second sensing element is a second grating body (27) including a second emitter (27a) and a second receiver (27b) arranged corresponding to the second emitter (27a), the second controller is a second grating controller, and the second emitter (27a) and the second receiver (27b) are respectively connected to the second grating controller.

4. The safety control device for adjacent workstations according to claim 1, characterized in that: The first sensing element is a first proximity sensor, and the first proximity sensor is connected to the first controller.

5. The safety control device for adjacent workstations according to claim 1, characterized in that: The second sensing element is a second proximity sensor, and the second proximity sensor is connected to the second controller.

6. The safety control device for adjacent workstations according to claim 1, characterized in that: The first sensing element is a first grating body (23) including a first emitter (23a) and a first receiver (23b) corresponding to the first emitter; the first controller is a first grating controller (25); the first emitter (23a) and the first receiver (23b) are respectively connected to the first grating controller (25); and The second sensing element is a second grating body (27) including a second emitter (27a) and a second receiver (27b) arranged corresponding to the second emitter, the second controller is a second grating controller, and the second emitter (27a) and the second receiver (27b) are respectively connected to the second grating controller.

7. The safety control device for adjacent workstations according to claim 6, characterized in that: The distance from the first sensing element to the second sensing element is the distance from a first grating (23c) emitted from the first emitter (23a) to the first receiver (23b) to a second grating (27c) emitted from the second emitter (27a) to the second receiver (27b).

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