Device for supplying coolant and cooling water system

Abstract

The invention relates to a device (25) for supplying a coolant, in particular water, to a machining device (2), such as a welding device or a welding robot, the machining device (2) having at least two regions or tools (16a, 16b) intended to be cooled, such as weld caps, wherein the areas or tools (16a, 16b) intended to be cooled are contained in an open or closed coolant circuit having a supply side (20) and a return side (21), where the vacuum generating unit is located in the return side (21), and where each area or tool (16a, 16b) to be cooled has a supply side inlet (18a, 18b) and a return side outlet (19a, 19b); wherein valves (22a, 22b, 22c, 22d) are arranged upstream of each supply-side inlet (18a, 18b) and downstream of each return-side outlet (19a, 19b) of the region or tool (16a, 16b) to be cooled. The invention also relates to a cooling water system comprising such a device (5) for supplying coolant, a coolant supply line, a coolant return line, a coolant supply valve, a coolant return valve, a signal transmitter and a vacuum generating unit.

Description

[0001] The present invention relates to a device for supplying coolant to a processing device, such as a welding device, which is intended to be equipped with a liquid coolant, such as water.

[0002] For many years, coolant supply devices of the above type have been known in practice. They have a coolant supply side and a coolant return side. The coolant is pumped from the coolant supply side through a tool (such as a welding cap) to be cooled to the coolant return side. In this example, the tool is cooled by the coolant.

[0003] When it is intended to replace the tool, the coolant circuit is first interrupted by means of two shut-off valves, and then a pressure reduction is generated in the coolant circuit. For example, such a pressure reduction can be generated by means of a suction cylinder with volume regulation, as is known from DE 102019 204 208. Subsequently, the tool is removed from the coolant circuit. In order to activate the suction cylinder and / or the shut-off valves, a signal valve known, for example, from DE 10 2015 204 812 can be used.

[0004] A disadvantage of this configuration is that when the tool is removed, the pressure reduction disappears between the two shut-off valves in the entire coolant circuit. In this example, the cooling water can be discharged from the coolant circuit. In addition, the tool must be replaced in a specific order, because otherwise more cooling water will be discharged. In the case of tool movement, the cooling water is also discharged due to vibration.

[0005] Therefore, the object of the present invention is to configure and develop a device for supplying coolant of the type mentioned in the introduction in such a way that the discharge of cooling water is prevented or minimized using a structurally simple device.

[0006] Another object is to provide a cooling water system for such a device.

[0007] According to the present invention, the above object is achieved by the features of claim 1. Accordingly, a device is provided for supplying coolant to a processing device, such as a welding device or a welding robot, which is intended to be equipped with a liquid coolant, in particular water, wherein the processing device has at least two areas or tools to be cooled, such as welding caps, wherein the areas or tools to be cooled are included in an open or closed coolant circuit having a supply side and a return side, wherein a pressure reduction generating unit is arranged in the return side, and wherein each area or tool to be cooled has a supply side inlet and a return side outlet, characterized in that valves are arranged respectively in front of each supply side inlet of the area or tool to be cooled and behind each return side outlet.

[0008] The present invention is further implemented by a cooling water system having a device for supplying a coolant, a coolant source, a coolant tank, a coolant supply side valve, a coolant return side valve, a signal transmitter, and a pressure reduction generating unit according to any one of claims 1 to 8.

[0009] According to the present invention, it is first recognized that due to the valves before and after each tool, the pressure reduction does not disappear throughout the coolant circuit, but only locally in the tool area. In this way, the outflow of cooling water can be prevented when replacing the tool. Therefore, both tools can be replaced simultaneously and thus more quickly. In addition, the discharge of cooling water can be prevented during tool movement.

[0010] According to an advantageous embodiment of the present invention, the valves before the supply side inlet and after the return side outlet are in the form of check valves. Due to the use of check valves, the disappearance of pressure reduction in the entire coolant circuit can be prevented in a simple manner. In addition, the generated pressure reduction is automatically transmitted through the entire coolant circuit. Furthermore, the check valves can be integrated into the existing coolant circuit in a simple and cost-effective manner. In terms of structural space, the check valves are not very dense and do not require an external energy supply to be activated. In this example, the check valves can be oriented to allow the coolant to flow in the return side direction and prevent the coolant from flowing in the supply side direction.

[0011] Preferably, the minimum opening pressure of the check valve is 0.01 bar, preferably 0.02 bar, especially 0.05 bar. Thus, the small pump power of the coolant supply unit is sufficient to activate the check valve. Therefore, cost-effective pumps can be used.

[0012] In addition, the valves before the supply side inlet and after the return side outlet can also be controlled pneumatically, electrically, or hydraulically. The advantage of this is that in the case of an impending change, the valves can already be closed in advance. In this example, combinations can also be made, where some valves are in the form of check valves and other valves are configured to be actively controlled. Advantageously, the coolant circuit can be arranged in series to cool the areas or tools to be cooled. In this example, the coolant return side of the first tool is the coolant supply side of the second tool. The advantage of this is that a coolant circuit can be generated in a simple manner and process monitoring can be carried out in a fault-free manner with the aid of flow sensors. In this example, it is advantageous to arrange valves simultaneously in the return side outlet of the area or tool to be cooled and in the supply side inlet of another area or tool to be cooled. Since the return side of the first tool corresponds to the supply side of the second tool, separate valves can be used to fluidly separate the two tools from each other. The advantage of this is that fewer valves are required.

[0013] The coolant circuit can also cool the areas or tools to be cooled in a parallel arrangement. The advantage of this is that multiple tools can be directly connected to the cooling water supply side, and the cooling water is not heated by the previously cooled tools. In addition, the hydraulic resistance of the parallel pipes is smaller, and with the same pressure relationship, a higher volume flow rate can be achieved. According to an advantageous further development of the invention, when the pressure reduction generating unit is activated, a pressure reduction can be generated in the coolant circuit at the supply side inlet and the return side outlet of each area or tool to be cooled. The advantage of this is that only one pressure reduction generating unit is required to generate a pressure reduction in all tools.

[0014] In this example, the pressure reduction generating unit can in particular include a suction cylinder and / or a pump. The pump can be operated, for example, electrically, pneumatically or hydraulically. In addition, the pump can be directly integrated into the coolant circuit or provide a pressure reduction by means of a bypass. For example, the pump can include a Venturi nozzle or a jet pump.

[0015] Now, there are various possibilities to configure and develop the teaching of the invention in an advantageous manner. For this purpose, on the one hand, reference can be made to the claims dependent on claim 1, and on the other hand, reference can be made to the following explanation of the preferred exemplary embodiments of the invention with reference to the drawings. While explaining the preferred exemplary embodiments of the invention with reference to the drawings, the general preferred embodiments and further developments of the teaching are also explained. In the drawings:

[0016] Figure 1 shows an overview of a cooling water system according to an embodiment of the invention,

[0017] Figure 2 shows a cooling water system for a welding tong according to an embodiment of the invention,

[0018] Figure 3a shows a device for supplying coolant to a welding tong in a series arrangement according to an embodiment of the invention,

[0019] Figure 3b shows a device for supplying coolant to a welding tong in a parallel arrangement according to an embodiment of the invention,

[0020] Figure 4 shows the flow path in the welding tong handle according to an embodiment of the invention.

[0021] Figure 1 shows an overview of a cooling water system for an automatic welding system. In this example, the basic equipment in the form of a robot mounting plate 1 serves as the center for the cooling water connection. The workpiece 3 to be welded can be welded with the aid of the welding tong 2. Since high temperatures are generated during the welding operation, the welding tong must be cooled.

[0022] For cooling, cooling water is guided from the cooling water source 4 via the robot mounting plate 1 to the welding tongs 2. The cooling water cools the welding tongs at this location and then is guided back via the robot mounting plate to the cooling water tank 5. The valve within the robot mounting plate 1 is controlled via the signal transmitter 6. To activate the valve, compressed air supplied to the robot mounting plate 1 via the compressed air source 7 is used.

[0023] The robot mounting plate 1 is explained in detail in Figure 2 .

[0024] Starting from the cooling water source 4, the cooling water is guided to the welding tongs 2. The supply flow to the welding tongs 2 is controlled by means of a ball valve 8, which is activated by means of a pneumatic rotary actuator 9. The ball valve 8 with the pneumatic rotary actuator 9 can also be in the form of an electric or hydraulic valve. For example, in the event of a loss of the welding cap, a burst of the cooling water hose, a welding cap replacement or other process problems, the supply flow of the cooling water can be stopped by means of the ball valve 8.

[0025] After the cooling water has cooled the welding tongs 2, the cooling water is transferred to the cooling water tank 5. To prevent the cooling water from flowing back to the welding tongs 2, a check valve 10 is arranged. The check valve 10 can also be in the form of an electric, pneumatic or hydraulic valve.

[0026] Together with the closed ball valve 8, a decompression can be generated in the coolant circuit via a decompression generating unit (in this case in the form of a suction cylinder 11). The suction cylinder 11 can be activated electrically, hydraulically or pneumatically. It is also conceivable that the decompression generating unit is in the form of an electric, pneumatic or hydraulic pump, which pumps out the cooling water from the coolant circuit.

[0027] The ball valve 8 or the pneumatic rotary actuator 9 and the suction cylinder 11 can be activated by means of compressed air. For this purpose, the compressed air source 7 is connected to the ball valve 9 and the suction cylinder 11 via a five-way two-position valve 12 controlled by the signal transmitter 6. In the first state of the direction control valve 12, the pneumatic rotary actuator 9 is opened and the suction cylinder 11 does not generate decompression. In the second state of the direction control valve 12, the ball valve 8 is closed and the piston of the suction cylinder 11 moves inwards in order to generate decompression in the active space 13 of the suction cylinder 11. In this way, decompression is generated while the valve 8 is closed. Due to the closing of the ball valve 8 and the check valve 13, the disappearance of the decompression is prevented.

[0028] Figure 3aShows a device for supplying coolant to a welding tong in a series arrangement according to an embodiment of the present invention. The welding tong 2 includes two tong arms 14a, 14b, and the workpiece 3 is arranged between the two tong arms 14a, 14b. The tong arms 14a, 14b respectively include shanks 15a, 15b and welding caps 16a, 16b. With the welding caps 16a, 16b releasably arranged on the tong arms 14a, 14b, the workpiece 6 can be welded. In this example, the welding caps 16a, 16b must be cooled. For this purpose, a coolant circuit for supplying coolant is arranged in the device 25.

[0029] The coolant initially flows through the transformer 17 from the coolant supply side 20. It is also conceivable that the transformer 17 can also be cooled in a separate cooling circuit. The transformer 17 provides the electrical energy required for the welding operation. Subsequently, the coolant flows through the tong arms 14a, 14b, and the tong arms 14a, 14b are cooled in a series arrangement. The coolant initially flows through the supply side inlet 18a of the tong arm 14a and is then guided through the return side outlet 19b to the supply side inlet 18b of the additional tong arm 14b. Finally, the coolant returns to the coolant return side 21 through the return side outlet 19b of the additional tong arm 14b. Via the coolant return side 21, the coolant is removed from the welding tong 2.

[0030] The decompression generating unit 11 is arranged in the return side 21. In order to replace the welding caps 16a, 16b, the ball valve 8 is closed so that the coolant can no longer flow into the welding tong 2, and at the same time, decompression is generated by the decompression generating unit 11 in order to pump out the cooling water from the welding tong 2. However, when one of the welding caps 16a, 16b is removed, the decompression in both of the tong arms 14a, 14b disappears. The cooling water is thus discharged, which may cause corrosion of the workpiece 3 or other related equipment such as an automatic capper. In addition, the accumulation of cooling water may also lead to industrial accidents.

[0031] To prevent this, check valves 22a, 22b, 22c are respectively arranged in the supply-side inlets 18a, 18b and the return-side outlets 19a, 19b. Since the return-side outlet 19a of the first clamping arm 14a corresponds to the supply-side inlet 18b of the second clamping arm 14b, only one check valve 22b is arranged here in this example. Due to the check valves 22a, 22b, 22c, the decompression generated by the decompression generating unit 11 is automatically transmitted to all the cooling water areas of the welding tongs 2. If one of the two welding caps 16a, 16b is removed, due to the respective check valves 22a, 22b, 22c, the decompression disappears only in the respective clamping arms 14a, 14b, rather than in the entire coolant circuit. For example, when the welding cap 16b is removed, air flows into the clamping arm 14b. The check valve 22b prevents the air from reaching the first clamping arm 14a. Due to the check valve 22c, the cooling water is prevented from flowing out of the return side 21 and into the welding tongs. On the contrary, if the welding cap 16a is removed, the check valve 22a prevents air from flowing into the air supply side 20. At the same time, the check valve 22b prevents the cooling water from flowing back from the clamping arm 14b and prevents it from being discharged. In this way, the outflow of the cooling water is reduced or completely prevented. In addition, both of the welding caps 16a, 16b can be removed simultaneously. Furthermore, due to the movement of the welding tongs 2, the system vibration or pressure peak is prevented by means of the check valves 22a, 22b, 22c, preventing the uncontrollable water movement that causes the cooling water to be discharged.

[0032] In this example, the check valves 22a, 22b, 22c are arranged close to the welding arms, especially as close as possible structurally, so that as little cooling water as possible remains between the check valves 22a, 22b, 22c and within the clamping arms 14a, 14b. The cooling water between the check valves 22a, 22b, 22c and the clamping arms 14a, 14b can be moved by the suction cylinder 11 into the active space 13 of the suction cylinder. In particular, the active space 13 of the suction cylinder 11 can be adapted to the volume of the cooling water between the check valves 22a, 22b, 22c and the clamping arms 14a, 14b.

[0033] Figure 3b Another configuration of the device for supplying coolant is shown.

[0034] Different from the device for supplying coolant according to Figure 3a In contrast to the device for supplying coolant according to Figure 3bIn the device 25 for supplying coolant, the clamping arms 14a, 14b of the welding tongs 2 are cooled in a parallel arrangement. Cooling water flows from the supply side 20 through the transformer 17 and is split so that the cooling water flows into the supply side inlets 18a, 18b of the clamping arms 14a, 14b respectively. Subsequently, the cooling water flows back into the return side 21 via the return side outlets 19a, 19b. Accordingly, four check valves 22a, 22b, 22c, 22d are respectively arranged in the supply side inlets 18a, 18b and the return side outlets 19a, 19b so that the removal of the welding caps 16a, 16b only causes the pressure reduction in the respective clamping arms 14a, 14b to disappear.

[0035] Figure 4 Shows the flow path in the welding tong handle according to an embodiment of the present invention.

[0036] The clamping arm 14 includes a handle 15 (in the form of a welding tong handle in this example) and a welding cap 16. Via the supply side inlet 18, the cooling water in the internal cooling pipe 23 is guided to the welding cap 16. Here, the cooling water cools the welding cap 16 and is then pumped through the handle 15 to the return side outlet 19.

[0037] Regarding additional advantageous embodiments of the device according to the present invention, for the sake of avoiding repetition, reference may be made to the general part of the specification and the appended claims.

[0038] Finally, it should be clearly pointed out that the above exemplary embodiments of the device according to the present invention are only used to explain the claimed teachings and are not limited to the exemplary embodiments.

[0039] List of reference numerals

[0040] 1 Basic equipment

[0041] 2 Welding tongs

[0042] 3 Workpiece

[0043] 4 Cooling water source

[0044] 5 Cooling water tank

[0045] 6 Signal transmitter

[0046] 7 Compressed air source

[0047] 8 Ball valve

[0048] 9 Pneumatic rotary actuator

[0049] 10 Check valve

[0050] 11 Suction cylinder

[0051] 12 Two-position five-way valve

[0052] 13 Activity space

[0053] 14 Plier arm

[0054] 15 Handle

[0055] 16 Welding cap

[0056] 17 Transformer

[0057] 18 Supply - side inlet

[0058] 19 Return - side outlet

[0059] 20 Coolant supply side

[0060] 21 Coolant return side

[0061] 22 Check valve

[0062] 23 Internal cooling pipe

Claims

1. A device (25) for supplying a coolant to a processing device (2), such as a welding device or a welding robot, the processing device (2) being intended to be equipped with a liquid coolant, in particular water, wherein, The processing device (2) has at least two regions or tools (16a, 16b) intended to be cooled, such as welding caps, wherein the regions or tools (16a, 16b) intended to be cooled are included in an open or closed coolant circuit having a supply side (20) and a return side (21), wherein a pressure reduction generating unit (11) is arranged in the return side (21), and wherein each region or tool (16a, 16b) to be cooled has a supply side inlet (18a, 18b) and a return side outlet (19a, 19b); It is characterized in that valves (22a, 22b, 22c, 22d) are arranged respectively in front of each supply side inlet (18a, 18b) and behind each return side outlet (19a, 19b) of the region or tool (16a, 16b) to be cooled.

2. The device (25) according to claim 1, characterized in that The valves (22a, 22b, 22c, 22d) in front of the supply side inlets (18a, 18b) and behind the return side outlets (19a, 19b) are in the form of check valves.

3. The device (25) according to claim 2, characterized in that, The minimum opening pressure of the check valves (22a, 22b, 22c, 22d) is 0.01 bar, preferably 0.02 bar, especially 0.05 bar.

4. The device (25) according to any one of claims 1 to 3, characterized in that, The valves (22a, 22b, 22c, 22d) in front of the supply side inlets (18a, 18b) and behind the return side outlets (19a, 19b) can be pneumatically, electrically or hydraulically controlled.

5. The device (25) according to any one of claims 1 to 4, characterized in that, The coolant circuit cools the regions or tools (16a, 16b) to be cooled in a series arrangement.

6. The device (25) according to any one of claims 1 to 5, characterized in that, Valves are arranged simultaneously in the return side outlet (19a) of the region or tool (16a) to be cooled and in the supply side inlet (18b) of another region or tool (16b) to be cooled.

7. The device (25) according to any one of claims 1 to 6, characterized in that, The coolant circuit cools the regions or tools (16a, 16b) to be cooled in a parallel arrangement.

8. The device (25) according to any one of claims 1 to 7, characterized in that When the pressure reduction generating unit (11) is activated, a pressure reduction is generated in the coolant circuit at the supply side inlets (18a, 18b) and the return side outlets (19a, 19b) of each region or tool (16a, 16b) to be cooled.

9. The device (25) according to any one of claims 1 to 8, characterized in that, The pressure reduction generating unit (11) includes a suction cylinder or a pump.

10. A cooling water system having a device (25) for supplying coolant, a coolant source (4), a coolant tank (5), a coolant supply side valve (8), a coolant return side valve (9), a signal transmitter (6) and a pressure reduction generating unit (11) according to any one of claims 1 to 9.

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