Oil supply device and oil supply method

Abstract

The number of devices required to control the pump flow rate is reduced compared to conventional technology. [Solution] The oil supply device is an oil supply device that supplies oil to a hydraulic press device, and comprises at least one variable flow rate pump and a plurality of fixed flow rate pumps. Since the oil supply device comprises at least one variable flow rate pump and a plurality of fixed flow rate pumps, that is, not all of the pumps supplying oil are variable flow rate pumps, the equipment for controlling the flow rate of the pumps can be reduced compared to the conventional technology.

Description

Technical Field

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[0001] The technology of the present disclosure relates to an oil supply device and an oil supply method.

Background Art

[0002] In the large hydraulic press device disclosed in Patent Document 1, since the pressurizing cylinder is large, the amount of oil used increases. However, since there is no pressurizing pump that supplies a large amount of oil at once, the oil supply device includes a plurality of pressurizing pumps. All of the plurality of pressurizing pumps are variable flow pumps capable of changing the amount of oil (flow rate) sent out by the pump. Using each variable flow pump, the flow rate of the oil supplied to the oil supply device is controlled continuously from minimum to maximum.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, equipment for controlling the amount of oil supplied to the hydraulic press device with variable flow pumps, for example, a tilting control piston for changing the angle of a swash plate for adjusting the flow rate of the pump and a servo valve for tilting control for accurately adjusting the angle, are provided for each variable flow pump. Therefore, the number of parts of the oil supply device increases.

[0005] The technology of the present disclosure aims to provide an oil supply device and an oil supply method capable of reducing the equipment for controlling the flow rate of the pump compared to the prior art. <00.....​​​​​To achieve the above objective, an oil supply device according to a first aspect of the technology of this disclosure is an oil supply device for supplying oil to a hydraulic press device, comprising at least one variable flow rate pump and a plurality of fixed flow rate pumps.

[0007] A second aspect is an oil supply method for supplying oil to a hydraulic press device using at least one variable flow rate pump and a plurality of fixed flow rate pumps, comprising: selecting the pump to supply the oil from the at least one variable flow rate pump and the plurality of fixed flow rate pumps in accordance with the operation of the hydraulic press device, and supplying oil to the hydraulic press device from the selected pump; and, when the number of selected plurality of fixed flow rate pumps changes in accordance with the operation of the hydraulic press device, controlling the flow rate of oil supplied from the variable flow rate pump so that the amount of oil supplied to the hydraulic press device changes gradually before and after the change in the number of fixed flow rate pumps. [Effects of the Invention]

[0008] A first aspect of the technology of this disclosure is an oil supply system comprising at least one variable flow pump and a plurality of fixed flow pumps, that is, not all of the pumps supplying oil are variable flow pumps, so that the equipment for controlling the flow rate of the pumps can be reduced compared to the prior art.

[0009] In the second embodiment, the flow rate of oil supplied from the variable flow rate pump is controlled so that the amount of oil supplied to the hydraulic press device changes gradually before and after the number of items changes, thereby enabling the hydraulic press device to operate smoothly. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a block diagram showing an example of the configuration of the oil supply device 100 according to the embodiment. [Figure 2] Figure 2 is a diagram showing an example of a data table that illustrates the relationship between the pressurizing speed of the press, the number of fixed-flow pumps 4 and variable-flow pumps 2, and the ratio of the flow rate of variable-flow pumps 2 to the total flow rate. [Figure 3]Figure 3 shows an example of the total flow rate of oil supplied as a function of the pressurizing speed of the press. [Figure 4] Figure 4 shows an example of the total pump flow rate, which pumps supply the oil, and the flow rate of each variable flow rate pump when the press section of the pressure press device 10 moves back and forth between the upper limit UL and the lower limit LL. [Figure 5] This figure shows four modified pump units 1AB1, 1AB2, 1C, and 1D. [Modes for carrying out the invention]

[0011] [Embodiment] Embodiments of the technology of this disclosure will be described below with reference to the drawings.

[0012] (composition) The configuration of the oil supply device 100 according to this embodiment will be described. Figure 1 is a block diagram showing an example of the configuration of the oil supply device 100 according to this embodiment.

[0013] As shown in Figure 1, the oil supply device 100 includes at least one first pump unit 20A comprising at least one variable flow rate pump 2 provided on one side of the motor 6 shaft and at least one fixed flow rate pump 4 provided on the other side of the motor 6 shaft. In the example shown in Figure 1, the oil supply device 100 comprises two first pump units 20A comprising one variable flow rate pump 2 provided on one side of the motor 6 shaft and one fixed flow rate pump 4 provided on the other side of the motor 6 shaft. Multiple variable flow rate pumps 2, specifically two, are provided.

[0014] The oil supply device 100 includes at least one second pump unit 20B, each having at least one fixed flow rate pump 4 on one side and the other side of the motor 6 shaft. In the example shown in Figure 1, the oil supply device 100 includes three second pump units 20B, each having one fixed flow rate pump 4 on one side and the other side of the motor 6 shaft.

[0015] There are 2 variable flow rate pumps 2 and 8 fixed flow rate pumps 4. The number of each pump is predetermined based on the maximum amount of oil supplied according to the operation of the hydraulic press device 10, the maximum amount of oil that can be supplied from the variable flow rate pumps 2, and the maximum amount of oil that can be supplied from the fixed flow rate pumps 4, so that the total maximum amount that can be supplied by the variable flow rate pumps 2 and the fixed flow rate pumps 4 is equal to or greater than the maximum amount of oil supplied according to the operation of the hydraulic press device 10.

[0016] The oil supply device 100 comprises two first oil supply mechanisms 1A, each equipped with a first pump unit 20A, and three second oil supply mechanisms 1B, each equipped with a second pump unit 20B. The two first oil supply mechanisms 1A have the same configuration. The configuration of one first oil supply mechanism 1A will be described, and the description of the configuration of the other first oil supply mechanism 1A will be omitted. The three second oil supply mechanisms 1B have the same configuration. The configuration of one second oil supply mechanism 1B will be described, and the description of the configurations of the remaining second oil supply mechanisms 1B will be omitted.

[0017] The oil supply device 100 includes a tank 14.

[0018] The suction side of the variable flow rate pump 2 and the fixed flow rate pump 4 of the first oil supply mechanism 1A is connected to the other end of a suction pipe 22, one end of which is located in the first tank 14. One end of a supply pipe 24 is connected to the discharge side of the variable flow rate pump 2, and the other end of the supply pipe 24 is connected to one end of two branch supply pipes 26 and 30. The other ends of each of the two branch supply pipes 26 and 30 are connected to the integrated discharge pipe 40. Each of the two branch supply pipes 26 and 30 is provided with a switching mechanism 13 and 15. The switching mechanisms 13 and 15 switch so that when oil flows from one of the branch supply pipes 26 and 30, oil does not flow from the other branch supply pipe 26 and 30, and when oil flows from the other branch supply pipe 26 and 30, oil does not flow from one of the branch supply pipes 26 and 30. One end of a supply pipe 34 is connected to the discharge side of the fixed flow rate pump 4. The supply pipe 34 is equipped with a switching mechanism 11. The switching mechanism 11 switches between a state where oil flows from the supply pipe 34 and a state where oil does not flow from the supply pipe 34.

[0019] On the suction side of each flow rate fixed pump 4 of the second oil supply mechanism 1B, the other end of a suction pipe 22 whose one end is located in the tank 14 is connected. On the discharge side of each flow rate fixed pump 4, one end of a supply pipe 34 is connected, and the other end side of the supply pipe 34 is connected to an integrated discharge pipe 40. A switching mechanism 11 is provided in each supply pipe 34. The switching mechanism 11 switches between the case where oil flows from the supply pipe 34 and the case where oil does not flow from the supply pipe 34.

[0020] The supply pipe 34 of the first oil supply mechanism 1A and the integrated discharge pipe 40 are connected to one end of an integrated supply and discharge pipe 42. The other end of the integrated supply and discharge pipe 42 is connected to the pressing device 10.

[0021] The return side of the oil supply device 100 is located in the tank 14. One end of a discharge supply pipe 52 is connected to the pressing device 10. The other end of the discharge supply pipe 52 is located in the tank 14. A switching mechanism 55 is provided in the integrated supply and discharge pipe 42 and the discharge supply pipe 52.

[0022] The switching mechanism 55 switches to the first case, the second case, or the third case.

[0023] In the first case, in order to press the object to be pressed by the pressing part of the pressing device 10, oil is supplied to the pressing device 10 through the integrated supply and discharge pipe 42 so that the pressing part descends, and oil is discharged from the pressing device 10 to the tank 14 through the discharge supply pipe 52.

[0024] In the second case, it is the case where oil does not flow through the integrated supply and discharge pipe 42 and the discharge supply pipe 52.

[0025] In the third case, after the pressing of the object to be pressed is completed, in order to place the next object to be pressed, oil flows from the integrated supply and discharge pipe 42 through the discharge supply pipe 52 to the pressing device 10 so that the pressing part ascends, and oil is discharged from the pressing device 10 to the tank 14 through the integrated supply and discharge pipe 42.

[0026] The return side of the oil supply device 100 is located inside the tank 14.

[0027] The press device 10 is equipped with an actuator 12 for removing the object to be pressed using hydraulic pressure. The return side of the oil supply device 57 is located inside the tank 14.

[0028] The branch supply pipes 30 of each first oil supply mechanism 1A are connected to an integrated supply pipe 46. The integrated supply pipe 46 is connected to an actuator 12 for removing the object to be pressed. One end of a discharge supply pipe 56 is connected to the actuator 12. The other end of the discharge supply pipe 56 is located inside the tank 14. A switching mechanism 57 is provided between the integrated supply / discharge pipe 42 and the discharge supply pipe 56.

[0029] The switching mechanism 57 switches to the fourth case, the fifth case, or the sixth case.

[0030] In the fourth case, oil is supplied to the actuator 12 of the pressurized press device 10 via the integrated supply pipe 46 so that the actuator 12 can remove the object to be pressed, and the oil is discharged from the actuator 12 to the tank 14 via the discharge supply pipe 56.

[0031] The fifth case is when oil does not flow through the integrated supply pipe 46 and the discharge supply pipe 56.

[0032] In the sixth case, after the object to be pressed has been removed, oil flows from the integrated supply pipe 46 to the actuator 12 via the discharge supply pipe 56 so that the actuator 12 returns to its original position, and the oil is discharged from the actuator 12 to the tank 14 via the integrated supply pipe 46.

[0033] The oil supply device 100 includes a control device 80 that controls each of the above-mentioned devices. The control device 80 is composed of a computer and includes a storage device 80M. The control device 80 is an example of a "control unit" of the technology disclosed herein.

[0034] Figure 2 is a diagram showing an example of a data table illustrating the relationship between the press pressure speed (mm / s), the number of fixed-flow pumps 4 and variable-flow pumps 2, and the variable-flow ratio. The press pressure speed (mm / s) is the speed at which the press section of the hydraulic press device 10 presses the object to be pressed. The variable-flow ratio is the ratio of the flow rate of each variable-flow pump 2 to its own maximum flow rate. Figure 3 shows an example of the total flow rate of oil supplied from the oil supply device 100 to the hydraulic press device 10 in order to pressurize the object to be pressed.

[0035] The data table shown in Figure 2 is stored in the storage device 80M. The control device 80 uses the data table to select the oil supply pump from two variable flow rate pumps 2 and eight fixed flow rate pumps 4 according to the operation of the pressurized press device 10, and supplies oil to the hydraulic press device 10 from the selected pump. As shown in Figure 2, in the ranges of pressurizing speed (mm / s) 1 to 3, 4 to 6, 7 to 9, ... 25 to 27, the number of fixed flow rate pumps 4 is 0, 1, 2, ... 8, and in each range of pressurizing speed (mm / s) , the number of variable flow rate pumps 2 is 2. The control device 80 determines which fixed flow rate pumps 4 to supply oil from for each range of speed (oil flow rate (mm / s)) and controls the switching mechanisms 11, 13, and 15.

[0036] Furthermore, the control device 80 uses a data table to control the flow rate of oil supplied from the variable flow rate pump 2 so that when the number of selected fixed flow rate pumps 4 changes according to the operation of the pressure press device 10, the amount of oil supplied to the hydraulic press device 10 changes gradually before and after the change in the number of pumps. The above ratio for each variable flow rate pump 2 is determined for each speed (oil flow rate) from the amount of oil supplied, which is determined by each speed (oil flow rate) and the number of fixed flow rate pumps 4, so that the amount of oil supplied to the hydraulic press device 10 changes gradually before and after the change in the number of fixed flow rate pumps 4. The control of the variable flow rate pump 2 is performed by controlling the tilt control piston and the tilt control servo valve, etc., to accurately adjust the angle, as described above.

[0037] For example, when changing the number of fixed-flow pumps 4 from 3 to 4 (changing the speed from 12 mm / s to 13 mm / s), each variable-flow pump 2 is controlled so that the ratio of the flow rate of each variable-flow pump 2 to its own maximum flow rate decreases from 63% to 31%.

[0038] Furthermore, for example, if the number of fixed-flow pumps 4 is changed from 7 to 6 (changing the speed from 22 mm / s to 21 mm / s), the ratio of the flow rate of each variable-flow pump 2 to its own maximum flow rate is increased from 40% to 72%.

[0039] As a result, as shown in Figure 3, each variable flow rate pump 2 is controlled so that the total flow rate of oil supplied from the oil supply device 100 to the hydraulic press device 10 to pressurize the object to be pressed gradually increases as the pressurization speed increases.

[0040] (action) Next, the operation of this embodiment will be explained. Figure 4 shows an example of the total pump flow rate, which pumps supply the oil, and the flow rate of each variable flow rate pump 2 when the press section of the pressure press device 10 moves back and forth (press stroke S) between the upper limit UL and the lower limit LL.

[0041] Each pump is identified as follows. Specifically, the storage device 80M of the control device 80 stores identification information (P1 to P10) for each pump and identifies them as follows: In each first oil supply mechanism 1A, the variable flow rate pumps 2 are identified as P1 and P2, starting from the top of Figure 4. The fixed flow rate pumps 4 are identified as P3 and P4, starting from the top of Figure 4. The second oil supply mechanisms 1B are identified as P5 to P10, starting from the top of Figure 4 and from left to right.

[0042] As shown in Figure 4, in the press section of the pressure press device 10, at time t0, when the press section is lowered from the upper limit UL in order to press the object to be pressed, the press section begins to descend.

[0043] From time t0 to time t1, the switching mechanisms 11, 13, and 15 of all first pump units 20A and all second pump units 20B (i.e., all switching mechanisms 11, 13, and 15) are controlled to supply oil from all pumps (two variable flow rate pumps 2 and eight fixed flow rate pumps 4). From time t0 to time t1, the flow rate ratio of each variable flow rate pump 2 is 43%, and the total pump flow rate is R1. As a result, the press section descends at a downward speed v = 25 mm / s.

[0044] When time t1 arrives, the downward speed v of the press section is reduced to 10 mm / s until time t2 arrives. To this end, the control device 80 selects two variable flow rate pumps 2 and three fixed flow rate pumps 4 (fixed flow rate pumps 4 of two first oil supply mechanisms 1A and one oil supply mechanism 1B (pumps P3~5)) and controls all switching mechanisms 11, 13, and 15 to supply oil from each selected pump. In this case, the above ratio of the two variable flow rate pumps 2 is 27%.

[0045] However, if the oil supply from pumps P6-10 is stopped at time t1 and the ratio of the two variable flow rate pumps 2 is set to 27%, the total pump flow rate, which was R1 up to time t1, will rapidly decrease to R2 (=R1 / 2), which is smaller than R1, at time t1. The press speed of the press section of the press pump device 10 will suddenly slow down, making it impossible to operate the press pump device 10 smoothly, and there is a risk of failure. Therefore, at time t1, the ratio of the two variable flow rate pumps 2 is gradually reduced from 43% to 27% until time t11. As a result, the total pump flow rate gradually decreases from R1 to R2, and the downward speed of the press section gradually decreases. This allows the press pump device 10 to operate smoothly and prevents failure.

[0046] When time t2 arrives, the downward speed v of the press section is reduced to 5 mm / s until time t3 arrives. To this end, the control device 80 selects one fixed-flow pump and two variable-flow pumps 2, and controls all switching mechanisms 11, 13, and 15 to supply oil from the selected one fixed-flow pump and two variable-flow pumps 2. In this case, the above ratio of the two variable-flow pumps 2 is 39%.

[0047] However, if the oil supply from pumps P4-5 is stopped at time t2 and the ratio of the two variable flow rate pumps 2 (pumps P1 and P2) is changed from 27% to 39%, the total pump flow rate, which was R2 until time t2, will rapidly decrease to R3, which is smaller than R2, at time t2. As a result, the speed of the press section of the press pump device 10 will suddenly slow down, preventing the press pump device 10 from operating smoothly and potentially leading to a malfunction. Therefore, at time t2, the ratio of the two variable flow rate pumps 2 is gradually increased from 27% to 39% until time t22. This causes the total pump flow rate to gradually decrease from R2 to R3, and the downward speed of the press section to gradually decrease. This allows the press pump device 10 to operate smoothly and prevents malfunction.

[0048] At other times t3, t4, and t5, the amount of oil supplied from each variable pump 2 is adjusted so that the total pump flow rate changes gradually before and after each time. During the time range of t4 to t5, which is the upward movement phase of the press, pumps P1 to P6 are selected according to the upward side area and speed of the pressurizing cylinder 10S.

[0049] (effect) The oil supply device of this embodiment includes at least one variable flow rate pump 2 and a plurality of fixed flow rate pumps 4. In other words, not all of the pumps supplying oil are variable flow rate pumps 2, so the equipment for controlling the flow rate of the pumps can be reduced compared to the prior art. Therefore, the number of parts in the oil supply device can be reduced compared to the prior art.

[0050] Since at least one pump is provided on each motor shaft, the number of pump units and motors can be reduced compared to the case where only one pump is provided per motor. Therefore, the number of parts in the oil supply device can be reduced compared to conventional technology, the configuration of the oil supply device can be simplified, and space can be saved.

[0051] In the above embodiment, the flow rate of the oil supplied from the variable flow rate pump 2 is controlled so that the amount of oil supplied to the hydraulic press device 10 changes gradually before and after the number of items changes, thereby enabling the hydraulic press device to operate smoothly.

[0052] Even if one variable flow pump 2 fails, the remaining variable flow pumps 2 can control the flow rate of oil supplied from the variable flow pumps 2 so that the amount of oil supplied to the hydraulic press device 10 changes gradually before and after the change in the number of pumps.

[0053] The number of variable flow pumps 2 and fixed flow pumps 4 is predetermined based on the maximum amount of oil supplied according to the operation of the hydraulic press device 10, the maximum amount of oil that can be supplied from the variable flow pumps 2, and the maximum amount of oil that can be supplied from the fixed flow pumps 4, so that the total maximum amount that can be supplied from the variable flow pumps 2 and fixed flow pumps 4 is equal to or greater than the maximum amount of oil supplied according to the operation of the hydraulic press device 10. Therefore, even when the hydraulic press device requires the maximum amount of oil, that maximum amount of oil can be supplied.

[0054] [Differentiation] In the above embodiment (see Figure 1), the first pump unit 20A includes one variable flow rate pump 2 provided on one side of the motor 6 shaft and one fixed flow rate pump 4 provided on the other side of the motor 6 shaft.

[0055] The technology disclosed herein is not limited thereto. For example, as shown in Figure 5, pump unit 1AB1 or pump unit 1AB2 may be used instead of the two first pump units 20A. The number of pump units and motors can be reduced compared to the above embodiment.

[0056] The pump unit 1AB1 includes one fixed-flow pump 4 and one variable-flow pump 2 on one side and the other side of the motor 6 shaft.

[0057] The pump unit 1AB2 is equipped with two fixed-flow pumps 4 on one side of the motor 6 shaft and two variable-flow pumps 2 on the other side.

[0058] Instead of the two first pump units 20A, two pump units 1C may be used. Each pump unit 1C comprises one variable flow rate pump 2 located on one side of the motor 6 shaft and two fixed flow rate pumps 4 located on the other side of the motor 6 shaft. When two pump units 1C are used, two variable flow rate pumps 2 and four fixed flow rate pumps 4 are used. Therefore, the one second pump unit 20B shown in Figure 1 is omitted. The number of pump units and motors can be reduced by the above implementation.

[0059] Furthermore, the above embodiment (see Figure 1) includes three second pump units 20B (a total of six fixed-flow pumps 4). The technology of this disclosure is not limited thereto. For example, the system may include two pump units 1D as shown in Figure 4 (a total of six fixed-flow pumps 4). Each pump unit 1D has one fixed-flow pump 4 on one side of the motor 6 shaft and two fixed-flow pumps 4 on the other side. The number of pump units and motors can be reduced compared to the above embodiment. The number of fixed-flow pumps 4 and variable-flow pumps 2, the first pump unit 20A, and the second pump unit 20B are not limited to the example shown in Figure 1. The pump unit may be configured to have one pump per motor. [Explanation of symbols]

[0060] 2. Variable flow rate pump 4. Fixed flow rate pump 6 motors 10. Hydraulic press device 20A First pump unit 20B Second pump unit 100 Oil supply device

Claims

1. An oil supply device that supplies oil to a hydraulic press machine, At least one variable flow pump, Multiple fixed-flow pumps, An oil supply device equipped with the following features.

2. A first pump unit comprising at least one variable flow rate pump provided on one side of the motor shaft and at least one fixed flow rate pump provided on the other side of the motor shaft, At least one second pump unit comprising at least one of the flow rate fixed pumps on each of the one and the other sides of the motor shaft, The oil supply device according to claim 1, comprising:

3. The pump that supplies oil is selected from the at least one variable flow rate pump and the plurality of fixed flow rate pumps according to the operation of the hydraulic press device, and oil is supplied to the hydraulic press device from the selected pump, The system further includes a control unit that controls the flow rate of oil supplied from a variable flow rate pump so that, when the number of selected fixed flow rate pumps changes in accordance with the operation of the hydraulic press device, the amount of oil supplied to the hydraulic press device changes gradually before and after the change in the number of fixed flow rate pumps. The oil supply device according to claim 1.

4. The system comprises multiple variable flow rate pumps, The oil supply device according to claim 3.

5. The number of each of the at least one variable flow pump and the plurality of fixed flow pumps is: The maximum amount of oil supplied in accordance with the operation of the hydraulic press device, The maximum amount of oil that can be supplied from the at least one variable flow pump, The maximum amount of oil that can be supplied from the aforementioned multiple fixed-flow pumps, It is predetermined based on, The oil supply device according to claim 1.

6. An oil supply method for supplying oil to a hydraulic press device using at least one variable flow rate pump and a plurality of fixed flow rate pumps, The pump that supplies oil is selected from the at least one variable flow rate pump and the plurality of fixed flow rate pumps according to the operation of the hydraulic press device, and oil is supplied to the hydraulic press device from the selected pump. When the number of selected fixed-flow pumps changes in accordance with the operation of the hydraulic press, the flow rate of oil supplied from the variable-flow pump is controlled so that the amount of oil supplied to the hydraulic press changes gradually before and after the change in the number of pumps. An oil supply method including

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