JP3701868B2 - Fluid supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluid temperature control method, a fluid temperature control device, and a fluid supply device, and more particularly to a fluid temperature control technique that can be used for a fluid supply device suitable for supplying coolant to various devices such as machine tools. .
[0002]
[Prior art]
In general, when supplying coolant such as cooling water or oil to a machine tool, a liquid tank that contains the coolant, a temperature controller for controlling the temperature of the coolant in the liquid tank, and a coolant in the liquid tank. There is used a coolant supply device having a liquid feed pump for supplying to a spindle portion or the like of a machine tool. In this coolant supply device, the coolant supplied to the machine tool by the liquid feed pump is heated instead of performing a cooling action of a predetermined portion through the machine tool, and then recovered and returned to the liquid tank again. . Therefore, in order to always keep the coolant in the liquid tank near the predetermined temperature, the temperature controller is configured to cool the coolant in the liquid tank.
[0003]
[Problems to be solved by the invention]
However, many of the above temperature regulators usually have only a temperature regulation capability to maintain the coolant temperature within a range of plus or minus several degrees C. with respect to the set temperature, and when using such a temperature regulator, In machine tools with extremely high machining accuracy, the machining dimensions also vary due to changes in the cooling state of each part due to temperature fluctuations of the coolant, so it is not possible to obtain high machining accuracy corresponding to the original machining capacity in machine tools. There is a problem.
[0004]
On the other hand, some temperature regulators have relatively high accuracy used for special purposes, for example, some can maintain the coolant temperature within a range of about plus or minus 0.5 ° C. with respect to the set temperature. . However, since such a temperature controller is expensive, there is a problem that the equipment cost increases and the structure is complicated and delicate, so that maintenance is difficult. In recent years, in particular, there are cases where it is required to adjust the coolant temperature with higher accuracy than the above-mentioned relatively high temperature adjustment accuracy. I can not cope.
[0005]
Accordingly, the present invention solves the above-described problems, and an object of the present invention is to provide a method and apparatus capable of controlling the fluid temperature with extremely high accuracy by combining a plurality of types of control modes. . It is another object of the present invention to provide a method and apparatus capable of realizing highly accurate temperature control with an inexpensive and simple structure. Another object of the present invention is to realize a fluid supply device capable of supplying a fluid whose temperature is controlled with high accuracy by using the above method and apparatus.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a fluid temperature control method according to the present invention includes a first tank and a second tank that contain a fluid, temperature-controls the fluid in the first tank, and the fluid in the second tank. The amount of fluid movement from the first tank to the second tank is controlled according to the detected temperature.
[0007]
According to the present invention, the temperature of the fluid in the first tank is controlled, and the fluid is moved from the first tank to the second tank by a fluid movement amount corresponding to the detected temperature of the fluid in the second tank. Since the fluid whose temperature is controlled in one tank is moved to the second tank with a further controlled fluid movement amount, the fluid temperature in the second tank can be controlled with higher accuracy. For example, even if the control accuracy of the fluid temperature controlled in the first tank is relatively poor and the fluid temperature fluctuates, the fluctuation of the fluid temperature in the second tank is controlled by controlling the amount of movement of the fluid to the second tank. Therefore, the fluid temperature of the second tank can be controlled with higher accuracy.
[0008]
In the present invention, it is preferable to control the amount of fluid movement so that the fluid temperature of the second tank is maintained at a predetermined target temperature or a target temperature range. According to this means, it is possible to control the fluid temperature of the second tank with higher accuracy with respect to a predetermined target temperature or a target temperature range.
[0009]
In the present invention, when the fluid temperature in the second tank is affected from the outside so as to change (increase or decrease in temperature) only in a predetermined direction, the fluid temperature in the first tank is the fluid temperature in the second tank. It is preferable that the temperature of the second tank is set to be the temperature when the fluid temperature is changed in the direction opposite to the change direction of the fluid temperature. That is, when the fluid in the second tank is in a heat receiving environment (that is, in a state of receiving heat from the outside), the temperature control set temperature or set temperature range for the fluid in the first tank The median value is preferably lower than the median value of the target temperature or target temperature range of the fluid in the second tank. This makes it possible to control the fluid temperature in the second tank. In this case, it is desirable that the upper limit of the set temperature range is not more than the target temperature or the lower limit of the target temperature range. As a result, the fluid temperature of the second tank can be reliably or more quickly maintained within the target temperature or the target temperature range. Further, when the fluid in the second tank is in a heat radiation environment (that is, in a state in which heat is released to the outside), a set temperature or a set temperature range for temperature control on the fluid in the first tank It is preferable to make the median value of the fluid higher than the median value of the target temperature or target temperature range of the fluid in the second tank. This makes it possible to control the fluid temperature in the second tank. In this case, it is desirable that the lower limit of the set temperature range is greater than or equal to the target temperature or the upper limit of the target temperature range. As a result, the fluid temperature of the second tank can be reliably or more quickly maintained within the target temperature or the target temperature range.
[0010]
In the present invention, when the fluid in the second tank is in a heat receiving environment, the average value of the fluctuation range of the fluid temperature in the first tank is the target temperature or target temperature of the fluid temperature in the second tank. It is preferable to make it lower than the median of the range. In this case, it is desirable that the upper limit of the fluctuation range of the fluid temperature of the first tank is equal to or lower than the target temperature of the fluid temperature of the second tank or the lower limit of the target temperature range. Further, when the fluid in the second tank is in a heat radiation environment, the average value of the fluctuation range of the fluid temperature in the first tank is the target temperature of the fluid temperature in the second tank or the median value of the target temperature range. Higher than that. In this case, it is desirable that the lower limit of the fluctuation range of the fluid temperature of the first tank is equal to or higher than the target temperature of the fluid temperature of the second tank or the upper limit of the target temperature range.
[0011]
In the present invention, it is preferable that the amount of fluid movement is controlled while the fluid is refluxed from the second tank to the first tank. According to this means, when the fluid is moved from the first tank to the second tank and the fluid temperature of the second tank is controlled, the fluid is refluxed from the second tank to the first tank. Since heat exchange between the first tank and the second tank can be promoted, the fluid temperature of the second tank can be controlled more easily or more quickly.
[0012]
Next, the fluid temperature control device of the present invention includes temperature control means for controlling the temperature of the fluid in the first tank, and fluid moving means for moving the fluid temperature-controlled by the temperature control means to the second tank. And temperature detection means for detecting the fluid temperature in the second tank, and movement amount control means for controlling the amount of fluid movement by the fluid movement means in accordance with the detected temperature detected by the temperature detection means. Features.
[0013]
In this invention, it is preferable that the said movement amount control means controls the said fluid movement amount so that the fluid temperature of the said 2nd tank is hold | maintained at predetermined | prescribed target temperature or a target temperature range.
[0014]
In this invention, it is preferable to have a reflux path for refluxing the fluid from the second tank to the first tank.
[0015]
Next, the fluid supply apparatus of the present invention is a fluid supply apparatus configured to supply a temperature-controlled fluid, and a first tank and a second tank that contain the fluid, and a fluid temperature of the first tank Temperature control means for controlling the fluid, fluid moving means for moving the fluid from the first tank to the second tank, temperature detection means for detecting the fluid temperature of the second tank, and the detected temperature of the temperature detection means And a movement amount control means for controlling the amount of fluid movement from the first tank to the second tank, and a fluid supply means for supplying the fluid from the second tank.
[0016]
In this invention, it is preferable that the said movement amount control means controls the said fluid movement amount so that the fluid temperature of the said 2nd tank is hold | maintained at predetermined | prescribed target temperature or a target temperature range.
[0017]
In this invention, it is preferable to have a reflux path for refluxing the fluid from the second tank to the first tank.
[0018]
In each of the above-mentioned inventions, means for increasing or decreasing the amount of fluid movement according to the fluid temperature of the first tank or means for increasing or decreasing the amount of fluid movement according to the fluid temperature of the first tank (movement amount control function) Is preferably provided. More specifically, when the fluid temperature in the second tank is lowered by moving the fluid in the first tank, the fluid moves when the fluid temperature in the first tank is lower than a predetermined value. When the fluid temperature of the first layer is higher than a predetermined value, the amount of fluid movement is increased more than usual. Conversely, when the fluid temperature in the second tank is increased by moving the fluid in the first tank, the amount of fluid movement is normally set when the fluid temperature in the first tank is lower than a predetermined value. When the fluid temperature of the first layer is higher than a predetermined value, the amount of fluid movement is lowered than usual.
[0019]
Moreover, in each of the above inventions, the set temperature or set temperature range or temperature fluctuation range of the first tank is brought closer to or away from the target temperature or target temperature range or temperature fluctuation range of the second tank, Alternatively, means for making the set temperature or set temperature range or temperature fluctuation range of the first tank approach or separate from the target temperature or target temperature range or temperature fluctuation range of the second tank (first tank temperature setting control function ) Is preferably provided.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of a fluid temperature control method, a fluid temperature control device, and a fluid supply device according to the present invention will be described in detail with reference to the accompanying drawings. The embodiment described below relates to a coolant supply device that supplies coolant such as cooling water, oil (including lubricating oil), and the like for machine tools, but the present invention is not limited to the coolant as described above. The present invention can be widely applied to temperature control methods, temperature control devices, and supply devices for fluids including various liquids, gases, and other fluids.
[0021]
FIG. 1 is a schematic configuration diagram schematically illustrating the overall configuration of the coolant supply apparatus 100 of the present embodiment. The coolant supply apparatus 100 includes a first tank 101 that contains the coolant C1, a second tank 102 that contains the coolant C2, a temperature controller 103 that controls the temperature of the coolant C1 in the first tank 101, and a first tank 101. A liquid feed pump 104 for sending the coolant C1 in the tank 101 to the second tank 102, a temperature sensor 105 for detecting the temperature of the coolant C2 in the second tank 102, and a liquid feed pump 104 based on the detected temperature of the temperature sensor 105. And a liquid feed pump 107 that sends the coolant C2 in the second tank 102 to the outside, for example, the machine tool 200 in the illustrated example.
[0022]
The temperature controller 103 has a built-in refrigerator, allows the refrigerant cooled by the refrigerator to pass through the heat exchange unit 103a, and cools the coolant C in the first tank 101 by the heat exchange unit 103a. . The liquid feed pump 104 sends out the coolant C1 in the first tank 101 to the second tank 102 through the moving tube 108. A reflux path 112 is provided between the first tank 101 and the second tank 102, and when the liquid level of the coolant C2 in the second tank 102 rises, the coolant returns to the first tank 101 through the reflux path 112 due to overflow. Is configured to do.
[0023]
When the temperature detected by the temperature sensor 105 rises, the pump control unit 106 moves the coolant from the first tank 101 to the second tank 102 or increases the amount of movement of the coolant, and conversely, the temperature detected by the temperature sensor 105. Is lowered, the movement of the coolant from the first tank 101 to the second tank 102 is stopped or the movement amount of the coolant is reduced.
[0024]
The second tank 102 is provided with a stirrer 109 equipped with a stirring means 109a such as a stirring blade for stirring the coolant C2 inside. In addition, the liquid feed pump 107 sends out the coolant C2 in the second tank 102 to the outside (machine tool 200) through the supply pipe 110. Further, the coolant is returned from the outside (machine tool 200) to the second tank 102 through the recovery pipe 111. Here, the temperature of the coolant returning from the machine tool 200 to the second tank 102 becomes higher than the temperature t of the coolant C <b> 2 in the second tank 102 by being heated inside the machine tool 200. The temperature of the coolant that returns to the second tank 102 varies depending on the operating state of the machine tool 200. At this time, in the case of the coolant supplied to the cutting portion of the machine tool 200, for example, about 30 ° C. is normally raised to 38 to 39 ° C. during heavy cutting. As described above, since the amount of heat received by the coolant C2 in the second tank 102 also varies due to a change in the external situation, it is necessary to control the temperature of the second tank 102 as described later.
[0025]
In the present embodiment, even with only the above-described configuration, the temperature controller 103, the pump control unit 106, the liquid feed pump 107, and the stirrer 109 are individually operated to achieve desired operation modes and objects described later. be able to. In an experiment conducted by the present inventor, when the limit of keeping the coolant temperature T of the first tank within the range of about plus or minus 3 ° C. of the set temperature with the temperature control capability of the temperature controller 103 is the limit. The coolant temperature t of the target temperature could be kept within a range of 0.1 to 0.2 ° C. of the target temperature. This is an accuracy that can be sufficiently effective even when used for a machine tool having the highest level of machining accuracy.
[0026]
In the present embodiment, as shown in the figure, a control device 113 is further provided to control the temperature controller 103, the pump controller 106, the liquid feed pump 107, and the agitator 109 (or at least one of them). You may comprise as follows. The control device 113 supplies a drive signal, a control signal, drive power, and the like for each of the above units in a predetermined control mode. The control device 113 may be any device as long as it has the functions described above, and can be configured by, for example, a programmable controller or an MPU (microprocessor unit).
[0027]
In the present embodiment, the temperature of the coolant C1 in the first tank 101 is controlled by the temperature controller 103 so as to be maintained within an appropriate temperature range. In this case, for convenience of explanation to be described later, it is assumed that the set temperature of the temperature controller 103 is T ₀ and the variation range of the temperature T of the coolant C ₁ is T ₀ + ΔT _{1 to} T ₀ −ΔT ₂ . In general, the accuracy of the control temperature of the temperature controller 103 is not high, and the temperature fluctuation of the coolant C1 is about plus or minus several degrees Celsius. As the temperature control method of a thermoregulator 103, on-off control system for on-off operation at a set temperature T ₀ or temperature from the temperature away predetermined temperature, proportional control to provide a proportional output in a predetermined temperature zone, including the set temperature T _0, In addition, any known temperature control method such as various control methods including an integral element and a differential element can be used.
[0028]
The coolant C1 whose temperature is controlled as described above is moved to the second tank 102 through the moving pipe 108 by the liquid feed pump 104 that operates in the drive mode controlled by the pump control unit 106. In the second tank 102, the stirrer 109 is normally operated to agitate the coolant C2 in the tank so that the entire coolant C2 has a substantially uniform temperature. From the second tank 102, the coolant C2 is supplied to the outside (machine tool 200) through the supply pipe 110 by the liquid feed pump 107. Normally, coolant that is substantially equal to the supply amount returns from the outside to the second tank 102 through the recovery pipe 111. Here, it is preferable to provide a purification means (such as a filtration filter) for purifying the coolant in the recovery path including the recovery pipe 111.
[0029]
The temperature of the coolant C2 in the second tank 102 is sent from the temperature sensor 105 to the pump control unit 106, and the pump control unit 106 changes the operation mode of the liquid feed pump 104 according to the detected temperature t of the coolant C2 by the temperature sensor 105. Control. Here, for convenience of explanation to be described later, the target temperature of the coolant C2 in the second tank 102 (that is, the target temperature of the coolant to be supplied) is t ₀ , and the target temperature range that is the target value of the temperature fluctuation range of the coolant C2 is t _{It is} assumed that ₀ + Δt _{1 to} t ₀ -Δt ₂ .
[0030]
As described above, in a state where the liquid feed pump 107 continues to send the coolant C2 in the second tank 102 to the outside (machine tool 200) through the supply pipe 110 and the coolant is recovered to the second tank 102 through the recovery pipe 111, The circulating coolant absorbs heat and the temperature of the coolant C2 in the second tank 102 rises. Therefore, in the present embodiment, the liquid feed pump 104 is operated according to the temperature detected by the temperature sensor 105, the amount of movement of the coolant C1 from the first tank 101 to the second tank 102 is controlled, and the coolant in the second tank 102 is controlled. The temperature is maintained at the target temperature t ₀ as described above, or is maintained within the target temperature range t ₀ + Δt _{1 to} t ₀ −Δt ₂ .
[0031]
At this time, the temperature T of the coolant C <b> 1 of the first tank 101 that is temperature-controlled by the temperature adjuster 103 indicates a temperature variation according to the temperature control mode and the temperature control capability of the temperature adjuster 103. The temperature fluctuation of the coolant C1 is shown in FIG. As shown in FIG. 2A, normally, the coolant temperature T repeatedly fluctuates up and down within a range of T ₀ + ΔT _{1 to} T ₀ −ΔT ₂ around the set temperature T ₀ of the temperature controller 103. .
[0032]
On the other hand, the coolant temperature t (detected by the temperature sensor 105) of the second tank 102 shown in FIG. 2B is a target temperature set higher than the upper limit T ₀ + ΔT ₁ of the fluctuation range of the coolant temperature T. It is kept in the vicinity of the t _0. More specifically, in the present embodiment, the lower limit t ₀ −Δt ₂ of the fluctuation range of the coolant temperature t centering on the target temperature t ₀ is higher than the upper limit T ₀ + ΔT ₁ of the fluctuation range of the coolant temperature T. It has become.
[0033]
When the coolant temperature t in the second tank 102 rises or becomes higher than the target temperature t ₀ , the pump control unit 106 operates the liquid feed pump 104 to move the coolant C 1 into the second tank 102. Alternatively, when the coolant C1 is already moving to the second tank 102, the amount of movement of the coolant C1 by the liquid feed pump 104 is increased. Thereby, the coolant temperature t of the second tank 102 is lowered by the low coolant temperature T. FIG. 2C shows an example of a change with time of the movement amount L of the coolant C1 by the liquid feeding pump 104. FIG. Examples shown in the illustrated solid line A, if the coolant temperature t has to be moved at a constant speed coolant C1 in the first tank 101 only when it is above the target temperature t ₀ to the second tank 102 (on-off control method) This shows the amount of coolant movement. That is, when the coolant temperature t in the second tank rises, the coolant C1 having a temperature T lower than that is introduced into the second tank, the coolant temperature t is lowered, and when the coolant temperature t falls, the movement of the coolant C1 is stopped. Thus, the coolant temperature t can be controlled within the fluctuation range t ₀ + Δt _{1 to} t ₀ −Δt ₂ .
[0034]
The control of the amount of movement of the coolant from the first tank 101 to the second tank 102 or the temperature control of the second tank in the present embodiment gives a proportional amount of movement in a predetermined temperature range in addition to the on / off control as described above. Arbitrary well-known control methods, such as proportional control and the various control methods which considered the integral element, the differential element, etc., can be used. For example, in the example shown by the broken line B in FIG. 2 (c), (to have for example, a positive correlation) according to the vertical fluctuation of the coolant temperature t, increase or decrease the amount of movement L around the threshold L ₀ Yes.
[0035]
In the present embodiment, the coolant temperature T of the first tank 101 varies within a variation range T ₀ + ΔT _{1 to} T ₀ −ΔT ₂ as shown in FIG. Then, based on the movement amount control function of the control device 113, by sending a control signal corresponding to the coolant temperature T from the control device 113 to the pump control unit 106, for example, a normal movement amount indicated by a broken line B in FIG. On the other hand, the coolant movement amount can be increased or decreased as indicated by a dotted line C in FIG. That is, when the coolant temperature T is high within the above fluctuation range, the coolant movement amount is increased more than usual to enhance the effect of lowering the coolant temperature t of the second tank 102, and the coolant temperature T is within the above fluctuation range. In the case where the coolant temperature is low, the coolant movement amount is reduced more than usual, and the effect of lowering the coolant temperature t of the second feed 102 is weakened, so that the temperature control of the coolant temperature t can be performed with higher accuracy. .
[0036]
Moreover, in this embodiment, in order to control the coolant temperature t of the second tank 102 with higher accuracy by the first tank temperature setting control function of the control device 113, the set temperature T of the coolant temperature T of the first tank 101 is set. ₀ or temperature fluctuation range T ₀ + ΔT _{1 to} T ₀ −ΔT ₂ can be adjusted up and down. For example, by bringing the set temperature or temperature fluctuation range of the coolant temperature T of the first tank 101 closer to the target temperature or temperature fluctuation range of the coolant temperature t of the second tank 102, Without increasing the control accuracy of the movement amount, the coolant temperature t of the second tank 102 can be made more accurate, that is, the fluctuation ranges Δt ₁ and Δt ₂ that determine the temperature fluctuation range can be reduced.
[0037]
If the coolant temperature of the first tank is brought close to the coolant temperature of the second tank using the first tank temperature setting control function, the influence on the coolant temperature of the second tank due to the fluctuation of the coolant temperature of the first layer is relative. Therefore, the first tank temperature setting control function is preferably used in combination with the above-described movement amount control function.
[0038]
Further, in the present embodiment, when the liquid level in the second tank 102 rises due to the movement of the coolant by the liquid feed pump 104 as described above, the coolant flows from the second tank to the first tank 101 through the reflux path 112 due to overflow. Therefore, the heat exchange between the first tank 101 and the second tank 102 increases, and the temperature of the second tank can be controlled quickly and with high accuracy.
[0039]
The fluid temperature control method, the fluid temperature control device, and the fluid supply device of the present invention are not limited to the illustrated examples described above, and various modifications can be made without departing from the scope of the present invention. is there.
[0040]
【The invention's effect】
As described above, according to the present invention, the second tank can be temperature-controlled with high accuracy without being greatly affected by the accuracy of temperature control for the first tank. Further, a complicated and expensive temperature control means is not required, and it can be configured simply and inexpensively.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram schematically showing an overall configuration of a coolant supply device according to an embodiment of the present invention.
FIG. 2 is a graph (a) showing a change over time in the coolant temperature T of the first tank, a graph (b) showing a change over time in the coolant temperature t of the second tank, and from the first tank to the second tank. It is a graph (c) which shows the time-dependent change of the amount L of coolant movement.
[Explanation of symbols]
100 Coolant supply device (fluid supply device)
101 1st tank 102 2nd tank 103 Temperature controller (temperature control means)
104 Liquid feed pump (fluid moving means)
105 Temperature sensor (temperature detection means)
106 Pump control unit (movement amount control means)
107 Liquid feed pump (fluid supply means)
108 moving pipe 109 stirrer 110 supply pipe 111 recovery pipe 112 reflux path 113 control device 200 machine tool

Claims (3)

Temperature control means for controlling the temperature of the fluid in the first tank, fluid moving means for moving the fluid temperature-controlled by the temperature control means to the second tank, and detecting the fluid temperature of the second tank Temperature detection means and fluid movement from the first tank to the second tank so as to keep the fluid temperature of the second tank at a target temperature or a target temperature range according to the detected temperature detected by the temperature detection means A movement amount control means for controlling the amount, a means for increasing or decreasing the fluid movement amount according to the fluid temperature of the first tank , a fluid supply means for supplying the fluid from the second tank to a supply target, and a supply target And a fluid recovery means for recovering the fluid to the second tank .   The fluid supply apparatus according to claim 1, further comprising a reflux path for refluxing the fluid from the second tank to the first tank. 3. The reflux path is configured such that when the amount of fluid in the second tank exceeds a predetermined amount, the fluid in the second tank returns to the first tank due to overflow. The fluid supply apparatus described.

Images