Heating system and heating method

Abstract

The oil temperature in each tank is raised without a heating mechanism on the prefill tank side. [Solution] A heating system for a hydraulic press device comprising a first tank and a second tank for storing oil, wherein the system heats the oil stored in the first tank to a target temperature or higher, and supplies the heated oil directly to the second tank without going through the hydraulic press device. In this way, the oil stored in the first tank is heated to a target temperature or higher, and the heated oil is supplied directly to the second tank without going through the hydraulic press device, so the temperature of the oil in each tank can be raised without providing a heating mechanism on the second tank side.

Description

Technical Field

[0001] The technology of the present disclosure relates to a temperature rising system and a temperature rising method.

Background Art

[0002] Conventionally, in a hydraulic press system equipped with a high-pressure pump, when the oil temperature of the hydraulic system is low (for example, 10°C or lower), the viscosity of the oil increases, the resistance on the suction side of the pump becomes large, and cavitation (bubbles) occurs in the oil, damaging the pump and reducing the pump's lifespan. Therefore, a conventional hydraulic press system is equipped with a temperature rising mechanism for raising the oil temperature. The temperature rising mechanism includes a heater or a circulation pump. In a conventional hydraulic press system, the temperature rising mechanism is arranged on the main tank side and not on the pre-filter tank side. This is because the necessity of equipping the pre-filter tank with a temperature rising mechanism is low in terms of usage frequency, while equipping the pre-filter tank side with a temperature rising mechanism requires costs (investment costs, etc.) and installation space for that purpose. Note that related technologies are disclosed in Patent Document 1.

[0003] Conventionally, after raising the oil temperature of the main tank, the pressurizing press device is idled to familiarize it with no load, and the oil in the main tank is supplied to the pre-filter tank via the pressurizing press device by a pressing operation, and the oil in the pre-filter tank is returned to the main tank.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when oil from the main tank is supplied to the prefill tank via a pressure press device, and then the oil from the prefill tank is returned to the main tank, the temperature of the oil in the prefill tank decreases as oil is supplied to it. Therefore, the oil that has cooled down is returned to the main tank, causing the oil in the main tank to cool down and reducing the lifespan of the pump.

[0006] The present invention aims to provide a heating system and heating method that can raise the temperature of the oil in each tank without requiring a heating mechanism on the prefill tank side. [Means for solving the problem]

[0007] To achieve the above objective, a first aspect of the technology of the present disclosure is a heating system comprising a first tank and a second tank for storing oil for a hydraulic press device, the heating system for heating the oil stored in the first tank and the second tank, the heating system heating the oil stored in the first tank and the heating system for directly supplying the heating system to the second tank.

[0008] A second embodiment comprises a first tank and a second tank for storing oil for a hydraulic press device, and a method for raising the temperature of the oil stored in the first tank and the second tank, comprising raising the temperature of the oil stored in the first tank and directly supplying the heated oil to the second tank. Includes. [Effects of the Invention]

[0009] Each aspect of the technology of this disclosure raises the temperature of the oil stored in the first tank to a target temperature or higher, and supplies the heated oil directly to the second tank without going through the hydraulic press device. Therefore, the temperature of the oil in each tank can be raised without providing a heating mechanism on the second tank side. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram of an example of the heating system 1 of this embodiment. [Figure 2] Figure 2 is a block diagram of an example of the electrical system of the heating system 1 of this embodiment. [Figure 3] Figure 3 is a diagram illustrating an example of the processing content of each functional unit of the CPU 52. [Figure 4] Figure 4 is a flowchart of an example of the temperature-raising press processing program 64P executed by the CPU 52. [Figure 5] Figure 5 is a flowchart showing an example of the subroutine for the upward processing in step 78 of Figure 4 in the first embodiment. [Figure 6] Figure 6 is a flowchart showing an example of the subroutine for the upward processing in step 78 of Figure 4 in the second embodiment. [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] [First Embodiment] (composition) The configuration of the heating system 1 of this embodiment will now be described. Figure 1 is a schematic diagram of an example of the heating system 1 of this embodiment. As shown in Figure 1, the heating system 1 of this embodiment comprises a main tank 10 and a prefill tank 30 for storing oil for a hydraulic press device 40, and is a heating system 1 that heats the oil stored in the main tank 10 and the prefill tank 30. The heating system 1 heats the oil stored in the main tank 10 to a target temperature or higher, and supplies the heated oil directly to the prefill tank 30 without going through the hydraulic press device 40. The prefill tank 30 is located at a lower position than the main tank 10, specifically at a position lower than the floor level FL. The prefill tank 30 may also be installed on top of the hydraulic press device 40, but in the case of large hydraulic press devices of several thousand tons or more, the press height becomes high, and due to building height restrictions, it may not be possible to install it on top. For this reason, it is installed at the bottom of the hydraulic press device. In this case, it is conceivable to install it on floor level FL, but the prefill tank 30 would occupy the workspace around the hydraulic press device 40, restricting the installation of equipment such as automatic handling devices or die changing devices. Therefore, the prefill tank 30 is installed in a pit below floor level FL.

[0013] The main tank 10 and the prefill tank 30 are examples of the "first tank" and "second tank" of the technology disclosed herein, respectively.

[0014] The heating system 1 includes a first temperature sensor 12 for detecting the temperature of the oil stored in the main tank 10, and a heating device 146 for heating the oil stored in the main tank 10.

[0015] The first temperature sensor 12 and the heating device 146 are examples of the "heating unit" and "temperature detection unit" of the technology disclosed herein, respectively.

[0016] The temperature-raising device 146 includes a pipe 15 that circulates the oil stored in the main tank 10, a filter 16, and a temperature-raising pump 14 that sucks the oil stored in the main tank 10 so as to circulate through the pipe 15 and the filter 16. When the temperature-raising pump 14 operates, a motor (not shown) provided inside is driven, the oil is heated by the temperature-raising pump 14, and the temperature of the oil rises. When the oil passes through the filter 16, foreign substances mixed in the oil are filtered out.

[0017] The temperature-raising system 1 includes an inert gas supply device 34 that supplies an inert gas (for example, nitrogen) to the pre-filter tank 30, and a second temperature sensor 36 that detects the temperature of the oil stored in the pre-filter tank 30.

[0018] The inert gas is, for example, nitrogen or argon. In the present embodiment, nitrogen is used. Hereinafter, the inert gas supply device 34 is referred to as a nitrogen supply device 34.

[0019] The nitrogen supply device 34 is an example of the "supply device" of the technology of the present disclosure.

[0020] The temperature-raising system 1 includes pipes (123A, 123B) connected between the main tank 10 and the pre-filter tank 30 without passing through the hydraulic press device 40. Specifically, the pipes (123A, 123B) include a first supply pipe 123A for supplying oil from the main tank 10 to the pre-filter tank 30 without passing through the hydraulic press device 40, and a second supply pipe 123B for supplying oil from the pre-filter tank 30 to the main tank 10 without passing through the hydraulic press device 40.

[0021] The first supply pipe 123A and the second supply pipe 123B are examples of the "first supply pipe" and the "second supply pipe" of the technology of the present disclosure.

[0022] One end of the first supply pipe 123A is connected to the main tank 10, and the other end is connected to the bottom of the prefill tank 30. The first supply pipe 123A is equipped with an auxiliary pump 20 that supplies oil stored in the main tank 10 to the prefill tank 30. When the auxiliary pump 20 is operating, oil stored in the main tank 10 is supplied to the top of the prefill tank 30.

[0023] One end of the second supply pipe 123B is connected to the bottom of the prefill tank 30, and the other end is connected to the main tank 10. The second supply pipe 123B is equipped with a circulation valve 32. As the nitrogen pressure in the prefill tank 30 increases due to the nitrogen supply device 34, opening the circulation valve 32 allows the relatively low-temperature oil stored at the bottom of the prefill tank 30 to be supplied to the main tank 10 via the second supply pipe 123B.

[0024] The hydraulic press device 40 and the prefill tank 30 are connected via a second pressurizing pipe 340. The second pressurizing pipe 340 is equipped with a valve 42. When the valve 42 opens, the nitrogen pressure in the prefill tank 30, which has been pressurized by the nitrogen supply device 34, supplies the oil stored in the prefill tank 30 to the hydraulic press device 40 via the second pressurizing pipe 340. As a result, the press section descends to the object to be pressed.

[0025] The main tank 10 and the hydraulic press device 40 are connected via a first pressurizing pipe 1240. The first pressurizing pipe 1240 is equipped with a pressurizing pump 18 and a valve 44 that supply oil stored in the main tank 10 to the hydraulic press device 40. When the valve 44 is open and the pressurizing pump 18 is driven, the oil stored in the main tank 10 is supplied to the hydraulic press device 40 via the first pressurizing pipe 1240. This causes the object to be pressed to be pressed.

[0026] Figure 2 is a block diagram of an example of the electrical system of the heating system 1 of this embodiment. As shown in Figure 2, the heating system 1 of this embodiment includes a control device 50 configured by a computer. The control device 50 includes a CPU 52, ROM 54, RAM 56, and input / output (I / O) ports 58. The CPU 52, ROM 54, RAM 56, and input / output (I / O) ports 58 are connected to each other via a bus 60 so as to be able to communicate with each other. A first temperature sensor 12, a second temperature sensor 36, a display device 62, a heating pump 14, a circulation valve 32, an auxiliary pump 20, a pressure pump 18, a nitrogen supply device 34, and a storage device 64 are connected to the input / output (I / O) ports 58.

[0027] The memory device 64 stores the temperature-increasing press processing program 64P (see Figure 4).

[0028] The functional section of the CPU 52 includes a data acquisition unit 52A, a prediction unit 52B, a display processing unit 52C, a lifting processing unit 52D, and a press processing unit 52E. The CPU 52 reads the temperature-raising press processing program 64P stored in the storage device 64 into the RAM 56 and executes it in the RAM 56, thereby functioning as the data acquisition unit 52A, prediction unit 52B, display processing unit 52C, lifting processing unit 52D, and press processing unit 52E.

[0029] Figure 3 is a diagram illustrating an example of the processing content of each functional unit of the CPU 52.

[0030] The intake unit 52A takes in the oil temperature of the main tank 10 detected by the first temperature sensor 12. The prediction unit 52B predicts the time it will take for the oil temperature stored in the main tank 10 and the prefill tank 30 to rise above the target temperature, based on the detected oil temperature in the main tank 10. The display processing unit 52C displays the predicted rise time on the display device 62.

[0031] The display device 62 is an example of a "notification unit" in the technology of this disclosure. Alternatively, the rising time may be notified by voice instead of the display device 62.

[0032] The heating unit 52D receives the oil temperature of the main tank 10 from the first temperature sensor 12 and the oil temperature of the prefill tank 30 from the second temperature sensor 36. Based on these oil temperatures, the heating unit 52D controls the heating pump 14, circulation valve 32, auxiliary pump 20, and nitrogen supply device 34 so that the oil circulates directly between the main tank 10 and the prefill tank 30 without going through the hydraulic press device 40, after the oil stored in the main tank 10 has risen to above the target temperature and until the oil temperature in the prefill tank 30 has risen to above the target temperature.

[0033] The press processing unit 52E controls the pressurizing pump 18 and the nitrogen supply device 34 to perform the press operation.

[0034] (action) Next, the operation of this embodiment will be explained.

[0035] Figure 4 is a flowchart of an example of a temperature-boosting press processing program 64P executed by the CPU 52. When the temperature-boosting press processing start button (not shown) is operated, the CPU 52 executes the temperature-boosting press processing program 64P. This executes the temperature-boosting press processing and the temperature-boosting press processing method.

[0036] In step 72, the intake unit 52A takes in the oil temperature of the main tank 10 detected by the first temperature sensor 12. In step 74, the prediction unit 52B predicts the time that the oil temperature of the oil stored in the main tank 10 and the prefill tank 30 will be above the target temperature, based on the detected oil temperature of the main tank 10.

[0037] In step 76, the display processing unit 52C displays the predicted rise time on the display device 62.

[0038] In step 78, the heating unit 52D performs a heating process to raise the temperature of the oil stored in the main tank 10 and the prefill tank 30 to a target temperature or higher.

[0039] In step 80, the press processing unit 52E performs the press operation.

[0040] (Prediction of the time of rise) Next, the process of predicting the rise time in step 74 will be explained. The prediction unit 52B predicts the time T (in hr) at which the temperature of the oil stored in the main tank 10 and the prefill tank 30 will be equal to or greater than the target temperature by substituting the detected oil temperature t1 in the main tank 10 into the following equation (1). T=C*(t2-t1) / (Q*α-A*K)...(1) C is the amount of heat required to raise the temperature of the oil stored in the main tank 10 and the prefill tank 30 by 1°C, and is calculated in advance using the following formula. C = Cp·Wp + CT·WT (unit: kcal / ℃) Cp is the specific heat of the oil (kcal / (kg·°C)), Wp is the mass of the oil (= specific gravity of the oil × amount of oil) (kg), CT is the specific heat of the tank material of the main tank 10 and the prefill tank 30 (kcal / (kg·°C)), and WT is the weight of the main tank 10 and the prefill tank 30 (kg). t1 is the detected oil temperature in the main tank 10. t2 is the target temperature (e.g., 20°C). Q is the amount of heat supplied (kcal), which is calculated in advance using the following formula. Q = β * P * q β is a coefficient, P is the pressure of the heating pump 14, and q is the flow rate of oil drawn by the heating pump 14. α is the efficiency, and A is the tank heat dissipation area (m²) between the main tank 10 and the prefill tank 30. 2 ) is the heat transfer coefficient (kcal / (m) between the tank surface of the main tank 10 and the prefill tank 30. 2 It is (°C·hr).

[0041] (Increasing process) Next, the raising process in step 78 will be described with reference to Figure 5. Figure 5 is a flowchart showing an example of the subroutine for the raising process in step 78 of Figure 4 in the first embodiment.

[0042] Step 78, the heating process, includes raising the temperature of the oil stored in the main tank 10 to above the target temperature and supplying the heated oil directly to the prefill tank 30 without going through the hydraulic press device 40. More specifically, under the control of the control device 50, the supply device 34 circulates the oil between the main tank 10 and the prefill tank 30 via the first supply pipe 123A and the second supply pipe 123B until the oil in the prefill tank 30 reaches or exceeds the target temperature after the oil in the main tank 10 has been raised to above the target temperature. A more detailed explanation follows below.

[0043] In step 90, the heating unit 52D determines whether the oil temperature in the main tank 10 is below the target temperature (for example, 20°C). If it is determined that the oil temperature in the main tank 10 is not below 20°C (target temperature), the heating process ends and the heating press process proceeds to step 80 (see Figure 4). If it is determined that the oil temperature in the main tank 10 is below 20°C (target temperature), the heating process proceeds to step 92.

[0044] When step 90 begins, the oil stored in the main tank 10 and the oil stored in the prefill tank 30 are at the same temperature, and if the oil temperature in the main tank 10 is below 20°C, the oil temperature in the prefill tank 30 is also below 20°C.

[0045] In step 92, the heating section 52D activates the heating pump 14 of the heating device 146. When the heating pump 14 is activated, a motor located inside the heating device 146 is driven, and the power of the heating pump 14 (power determined by the sum of the pump flow rate and pressure) causes the temperature of the oil drawn in by the heating pump 14 to rise. As the oil passes through the filter 16, any foreign matter mixed in the oil is filtered out. The heating pump 14 of the heating device 146 operates until the heating press process is completed.

[0046] In step 94, the heating unit 52D determines whether the oil temperature in the main tank 10 is 20°C (target temperature) or higher. If it is determined that the oil temperature in the main tank 10 is not 20°C or higher, the heating process proceeds to step 96.

[0047] In step 96, the heating unit 52D takes in the oil temperature of the main tank 10 detected by the first temperature sensor 12. Once the processing in step 96 is complete, the heating process returns to step 94. Therefore, the heating unit 52D determines again whether the oil temperature of the main tank 10 detected by the first temperature sensor 12 is 20°C or higher.

[0048] If it is determined that the oil temperature in the main tank 10 is 20°C or higher, the temperature rise process proceeds to step 98.

[0049] In step 98, the rise section 52D circulates the low-temperature oil from the prefill tank 30 while removing it. Specifically, as described above, one end of the second supply pipe 123B of the rise section 52D is connected to the bottom of the prefill tank 30, and the other end is connected to the main tank 10. With the circulation valve 32 open, the pressure inside the prefill tank 30 is increased by the nitrogen supply device 34, so the relatively low-temperature oil stored at the bottom of the prefill tank 30 is supplied to the main tank 10 via the second supply pipe 123B.

[0050] In step 100, the heating unit 52D sends heated oil from the main tank 10 to the prefill tank 30. Specifically, the heating unit 52D operates the auxiliary pump 20. When the auxiliary pump 20 is operating, the oil stored in the main tank 10 is supplied to the prefill tank 30 via the first supply pipe 123A.

[0051] As a result, the relatively low-temperature oil in the prefill tank 30 is supplied to the main tank 10 via the second supply pipe 123B, and the heated oil stored in the main tank 10 is supplied to the prefill tank 30 via the first supply pipe 123A.

[0052] In step 102, the rise processing unit 52D takes in the oil temperature of the prefill tank 30 detected by the second temperature sensor 36.

[0053] In step 104, the heating unit 52D determines whether the oil temperature in the prefill tank 30 is above the target temperature (for example, 20°C). If it is determined that the oil temperature in the prefill tank 30 is not above 20°C, the heating process returns to step 98 and repeats the above process (steps 98 to 104). If it is determined that the oil temperature in the prefill tank 30 is above 20°C, the heating process ends and the heating press process proceeds to step 80 (see Figure 4).

[0054] In this way, during the heating process, after the oil stored in the main tank 10 has been heated to above the target temperature, the oil is circulated between the main tank 10 and the prefill tank 30 via the first supply pipe 123A and the second supply pipe 123B until the temperature of the oil in the prefill tank 30 reaches or exceeds the target temperature.

[0055] As described above, the heating pump 14 of the heating device 146 operates until the heating press process is completed. Therefore, even if the process in steps 98 to 104 is repeated, the oil stored in the main tank 10 will not fall below the target temperature.

[0056] (Pressing process) Next, the pressing process in step 80 will be described. When the press is lowered without load, the press processing unit 52E opens valve 42 and sends the oil from the prefill tank 30 to the pressurizing cylinder device 40 using the nitrogen pressure of the prefill tank 30. When the press is loaded, valve 44 opens and drives the pressurizing pump 18.

[0057] Because the nitrogen in the prefill tank 30 is pressurized by the nitrogen supply device 34, when the valve 42 is open, the oil stored in the prefill tank 30 is supplied to the hydraulic press device 40 via the second pressurizing pipe 340 due to the pressure of the oil in the prefill tank 30. As a result, the press section descends to the object to be pressed.

[0058] When the valve 44 is open and the pressure pump 18 is driven, the oil stored in the main tank 10 is supplied to the hydraulic press device 40 via the first pressurizing pipe 1240. This causes the object to be pressed to be pressed.

[0059] (effect) In this embodiment described above, the oil stored in the main tank 10 is heated to a temperature above the target temperature, and the heated oil is supplied directly to the prefill tank 30 without going through the hydraulic press device 40. Therefore, the temperature of the oil in each tank, the main tank 10 and the prefill tank 30, can be raised without providing a heating mechanism on the prefill tank 30 side. Since the prefill tank 30 side does not have a heating mechanism, the cost (investment cost) and installation space required for providing a heating mechanism on the prefill tank side can be eliminated.

[0060] Since the temperature of the oil in the prefill tank 30 is also raised using the heating device 146 that raises the temperature of the oil stored in the main tank 10, the existing heating device 146 can be effectively utilized.

[0061] Under the control of the control device 50, the supply device 34 circulates the oil between the main tank 10 and the prefill tank 30 via the first supply pipe 123A and the second supply pipe 123B until the oil stored in the main tank 10 has risen to above the target temperature, and the oil temperature in the prefill tank 30 has risen to above the target temperature. Therefore, in this embodiment, temperature variations in the oil in each tank, the main tank 10 and the prefill tank 30, can be reduced. As a result, the temperature is kept constant, the viscosity of the oil in the hydraulic system is stabilized, stable hydraulic performance is maintained, and the lifespan of the pressurizing pump can be extended.

[0062] Conventionally, after raising the oil temperature in the main tank, the pressure press device is run without load to break in, and the oil from the main tank is supplied to the prefill tank via the pressure press device through the press operation, and the oil from the prefill tank is returned to the main tank. In this case, the cooled oil from the prefill tank returns to the main tank, the oil temperature in the main tank drops, and it is necessary to operate the heating mechanism again, requiring the operator to be present. However, in this embodiment, based on the oil temperature of the main tank 10, the time it will take for the oil temperature stored in the main tank 10 and the prefill tank 30 to reach or exceed the target temperature after the heating process is predicted. Therefore, the predicted time can be communicated to the operator.

[0063] In this embodiment, the predicted time is displayed on the display device 62, so the operator can see the displayed rise time on the display device 62 and know how long they need to return before the pressing process (step 80). Therefore, the operator can be freed from constraints and can effectively use that time for other work, etc.

[0064] During the break-in period described above, when supplying oil from the main tank to the prefill tank via the press device through the press operation, and returning the oil from the prefill tank to the main tank, the oil in the cylinders of the press device is returned to the prefill tank once per cycle (in small amounts) in accordance with the press's lifting and lowering cycle. At this time, if the oil level in the prefill tank exceeds the standard oil level, it is necessary to return the excess amount to the main tank before the next cycle. For this reason, it took a considerable amount of time for the oil, including the oil in the prefill tank, to reach its maximum temperature.

[0065] However, in this embodiment, the oil stored in the main tank 10, which has been heated to above the target temperature, is supplied directly to the prefill tank 30 without a break-in period. Therefore, the time required for the oil in the prefill tank to reach its maximum temperature, including the oil itself, can be shortened compared to the conventional technology.

[0066] Furthermore, one end of the first supply pipe 123A is connected to the main tank 10, and the other end is connected to the top of the prefill tank 30. One end of the second supply pipe 123B is connected to the bottom of the prefill tank 30, and the other end is connected to the main tank 10. Therefore, the relatively low-temperature oil stored at the bottom of the prefill tank 30 is supplied to the main tank 10 via the second supply pipe 123B, and the heated, relatively high-temperature oil is supplied to the top of the prefill tank 30 via the first supply pipe 123A. Thus, the oil in the prefill tank 30 can be heated efficiently and in a short time.

[0067] [Second Embodiment] (composition) The configuration of the second embodiment is the same as that of the first embodiment, so its description will be omitted.

[0068] (action) Since the operation of the second embodiment is substantially the same as that of the first embodiment, the main differences will be omitted.

[0069] In the second embodiment, the lifting process in step 78 of the press process is performed as shown in Figure 6, instead of the lifting process shown in Figure 5.

[0070] Figure 6 is a flowchart showing an example of the subroutine for the lifting process in step 78 of Figure 4 in the second embodiment. The lifting process in the second embodiment has parts that are the same as the lifting process in the first embodiment (see Figure 4), so the same reference numerals are used for the same parts, and their brief descriptions are omitted, while the parts that are mainly different are omitted.

[0071] In the heating process of the second embodiment, the supply device 34, under the control of the control device 50, supplies all the oil in the prefill tank 30 to the main tank 10 via the second supply pipe 123B before the oil stored in the main tank 10 rises above the target temperature, and when the oil stored in the main tank 10 rises above the target temperature, it supplies the oil stored in the main tank 10 to the prefill tank 30 via the first supply pipe 123A. This will be explained in more detail below.

[0072] In step 90, the rise processing unit 52D determines whether the oil temperature in the main tank 10 is below the target temperature (for example, 20°C). If the oil temperature in the main tank 10 is below 20°C, in step 98, the rise processing unit 52D sends the low-temperature oil from the prefill tank 30 to the main tank 10.

[0073] In the next step 116, the lifting unit 52D determines whether the transfer of oil from the prefill tank 30 to the main tank 10 is complete. The time required for all the oil in the prefill tank 30 to be transferred to the main tank 10 is predetermined from the time the low-temperature oil from the prefill tank 30 is transferred to the main tank 10 in step 98. Alternatively, an oil level gauge (not shown) may be installed in the prefill tank 30 to pre-set a minimum oil level signal indicating completion of the transfer. In step 116, the lifting unit 52D determines whether the transfer of oil from the prefill tank 30 to the main tank 10 is complete by determining whether the time has elapsed since the time the low-temperature oil from the prefill tank 30 was transferred to the main tank 10 in step 98. Alternatively, the unit may determine that the transfer of oil to the main tank 10 is complete based on a signal indicating whether the oil level on the oil level gauge (not shown) in the prefill tank 30 has reached the minimum level.

[0074] When step 98 begins, both the oil stored in the main tank 10 and the oil stored in the prefill tank 30 are below 20°C. Through the processes of steps 98 and 110, all the oil in the prefill tank 30 is supplied to the main tank 10 via the second supply pipe 123B before the oil stored in the main tank 10 rises above the target temperature.

[0075] Once all the oil in the prefill tank 30 has been supplied to the main tank 10 via the second supply pipe 123B, in the next step 92, the heating section 52D operates the heating pump 14 of the heating device 146 to raise the temperature of the oil drawn in by the heating pump 14.

[0076] Next, in step 94, the heating unit 52D determines whether the oil temperature of the main tank 10 is 20°C (target temperature) or higher. If it is determined that the oil temperature of the main tank 10 is not 20°C or higher, the heating process proceeds to step 96, in which step 96 the heating unit 52D takes in the oil temperature of the main tank 10 detected by the first temperature sensor 12, and the heating process returns to step 94. Thus, the heating unit 52D determines again whether the oil temperature of the main tank 10 detected by the first temperature sensor 12 is 20°C or higher.

[0077] If it is determined that the oil temperature in the main tank 10 is 20°C or higher, the temperature rise process proceeds to step 124.

[0078] In step 124, the heating section 52D stops the heating pump 14 of the heating device 146.

[0079] In the next step 100, the lifting unit 52D operates the auxiliary pump 20 so that oil returns from the main tank 10 to the prefill tank 30. At the start of the process in step 100, the prefill tank 30 is empty, and the time required for oil to return from the main tank 10 to the prefill tank 30 and for a predetermined amount to be stored in the prefill tank 30 is predetermined. Alternatively, an oil level gauge (not shown) may be installed in the prefill tank 30, and an oil level position signal for a predetermined amount of storage may be set in advance. In step 100, the lifting unit 52D stores a predetermined amount in the prefill tank 30 by operating the auxiliary pump 20 for the given time. Alternatively, the operation of the auxiliary pump 20 may be stopped when the oil level on the oil level gauge (not shown) of the prefill tank 30 reaches a predetermined storage level.

[0080] Once the process in step 100 is complete, the rising process ends, and the heating press process proceeds to step 80 (see Figure 4).

[0081] (effect) The configuration of the second embodiment is the same as that of the first embodiment, and the operation of the second embodiment is substantially the same as that of the first embodiment; therefore, the second embodiment achieves the effects of the first embodiment.

[0082] The oil in the prefill tank 30 is first supplied entirely to the main tank 10, where the temperature of all the oil is raised. This centralizes the temperature control, eliminating the need to manage the temperature within the prefill tank 30, thus simplifying the control of the entire system.

[0083] [Differentiation] In the first and second embodiments, a heating device 146 comprising piping 15, a filter 16, and a heating pump 14 is provided. However, the technology of this disclosure is not limited thereto, and a heater may be provided in place of or together with the heating device 146.

[0084] In the heating process of the second embodiment, the supply device 34 supplies all of the oil in the prefill tank 30 to the main tank 10 via the second supply pipe 123B before the oil stored in the main tank 10 has been heated. The technology of this disclosure is not limited thereto. The supply device 34 may supply at least some (but not all) of the oil in the prefill tank 30 to the main tank 10 via the second supply pipe 123B before the oil stored in the main tank 10 has been heated. [Explanation of Symbols]

[0085] 1. Heating System 10 Main Tank 30 prefill tanks 34 Nitrogen supply system 40 Hydraulic press equipment 12 Temperature detection sensors 52 CPU 52A Intake section 52B Prediction Unit 52C Display Processing Unit 52D Upward Processing Unit 52E Press Processing Unit 62 Display device 123A First supply pipe 123B Second supply pipe 146 Heating device

Claims

1. A heating system comprising a first tank and a second tank for storing oil for a hydraulic press device, and for raising the temperature of the oil stored in the first tank and the second tank, A heating system that heats the oil stored in the first tank and directly supplies the heated oil to the second tank.

2. The heating system according to claim 1, wherein the oil stored in the first tank is heated to a target temperature or higher, and the heated oil is supplied directly to the second tank without going through the hydraulic press device.

3. A piping system is provided that connects the first tank and the second tank without going through the hydraulic press device, A heating unit for raising the temperature of the oil stored in the first tank, A supply unit that supplies the heated oil to the second tank via the piping, A heating system according to claim 1, comprising:

4. The aforementioned piping is A first supply pipe for supplying the oil from the first tank to the second tank without going through the hydraulic press device, A second supply pipe for supplying the oil from the second tank to the first tank without going through the hydraulic press device, Includes, The supply unit circulates the oil between the first tank and the second tank via the first supply pipe and the second supply pipe until the oil stored in the first tank has risen to a target temperature or higher, and the oil temperature in the second tank has risen to a target temperature or higher. The heating system according to claim 3.

5. The aforementioned piping is A first supply pipe for supplying the oil from the first tank to the second tank without going through the hydraulic press device, A second supply pipe for supplying the oil from the second tank to the first tank without going through the hydraulic press device, Includes, The supply unit supplies oil from the second tank to the first tank via the second supply pipe before the oil stored in the first tank rises above the target temperature, and when the oil stored in the first tank rises above the target temperature, it supplies the oil stored in the first tank to the third tank via the first supply pipe. The heating system according to claim 3.

6. A temperature detection unit for detecting the temperature of the oil stored in the first tank, A prediction unit predicts the time it will take for the temperature of the oil stored in the first tank and the second tank to be above a target temperature, based on the detected oil temperature. A heating system according to any one of claims 1 to 5, further comprising the above.

7. The system further includes a notification unit that notifies the predicted time. The heating system according to claim 6.

8. A heating method comprising a first tank and a second tank for storing oil for a hydraulic press device, wherein the heating method is for raising the temperature of the oil stored in the first tank and the second tank, The oil stored in the first tank is heated, The heated oil is supplied directly to the second tank, A method of raising temperature that includes [details omitted].

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