JP2002039658A - Method and apparatus for controlling temperature of matter to be cooled by fluid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately carry out cooling without causing excessive cooling and insufficient cooling in the case the temperature of a plurality of object matters to be cooled is indirectly controlled by employing temperature control of a cooling fluid due to difficulty of direct measurement of temperature. SOLUTION: Temperatures of the cooling fluid at inlet sides and outlet sides of cooling paths for the object matters to be cooled 1, 2a and 2b, and flow rates of the cooling fluid flowing in the respective object matters, are measured. Appropriate target temperatures of the respective object matters 1, 2a and 2b are estimated on the basis of the measured temperatures and flow rates. Target values of the temperatures at the inlets or the flow rates of the cooling fluid distributed to the respective object matters are determined on the basis of the appropriate target temperatures. Flow rates of the respective object matters are controlled at the outlet sides in such a manner as to regulate the temperatures at the inlet, or the flow rates of the cooling fluid distributed to the respective object matters at the target values. Thus, the temperatures of the respective object matters 1, 2a and 2b are kept at the appropriate target temperatures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a temperature of an object to be cooled by a fluid, and more particularly to a method and apparatus for appropriately controlling temperature when a plurality of heat generating parts of a machine are cooled by circulating a cooling fluid. The present invention relates to a method and an apparatus for controlling a temperature of a cooled body, which can maintain a temperature at a target value.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional cooling device for circulating a cooling fluid to cool a plurality of heat generating parts. FIG. 2 shows an example in which a conventional cooling device is used for a machine tool. In machine tools, the spindle 1 and the ball screw 2 of the feed mechanism
In the portions where a and b generate a large amount of heat, cooling is performed by circulating cooling oil to prevent thermal deformation.

In FIG. 2, reference numeral 3 denotes a reservoir tank for cooling oil as a cooling fluid, and reference numeral 4 denotes a cooling pump.
The cooling oil discharged from the cooling pump 4 is cooled by a cooler 5 and then sent to an oil jacket 7 for cooling the main shaft 1 via a cooling pipe 6. The cooling oil led out of the oil jacket 7 of the main shaft 1 then flows through the cooling pipe 8 and passes through the ball screws 2a, 2b
Sent to FIG. 2 illustrates two ball screws 2a and 2b among a plurality of feed shafts of the machine. Each of the ball screws 2a and 2b is formed with a cooling passage penetrating in the axial direction.
Are connected in series. And ball screw 2
The cooling water that has cooled a and 2b flows through the cooling pipe 10 and is returned to the reservoir tank 3.

[0004] When cooling the heat-generating portion of a machine tool with the above-described cooling device, it is necessary to control the temperature of the heat-generating portion for proper cooling. However, in the case of a heat generating portion, such as the main shaft 1 and the ball screws 2a and 2b, for which it is difficult to directly measure the temperature, indirect temperature control must be performed by controlling the temperature of the cooling water. Sometimes.

[0005] Therefore, as shown in FIG. 2, conventionally, as shown in FIG. 2, cooling water is provided by providing temperature sensors 11 and 12 at an inlet of a cooling pump 4 and an outlet of a cooler 5, respectively. This is a temperature control method performed by taking the temperature into the control device 13. The controller 13 operates the cooling pump 4 to adjust the flow rate of the cooling oil, or adjusts the cooling capacity of the cooler 5 so that the temperature of the cooling water becomes a predetermined set temperature. Water temperature is controlled.

[0006]

However, when there are a plurality of heating parts such as the main shaft 1 and the ball screws 2a and 2b in the cooling oil circulation path as in the machine tool shown in FIG. As the main shaft 1 is cooled down the most, the cooling oil absorbs heat and rises in temperature as it goes downstream, and the cooling effect on the ball screw 2b located at the most downstream is considerably reduced. As a result, although the temperature of the cooling oil is controlled, there is a problem that a phenomenon such as excessive cooling of the spindle 1 and insufficient cooling of the ball screw 2b occurs.

In addition, it is inevitable that the temperatures of the main shaft 1, the ball screw 2a, and the ball screw 2b actually cooled are inevitably varied, and it is very difficult to maintain a constant target temperature as a whole. Met.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and it is difficult to directly measure the temperature, and the temperature of a plurality of objects to be cooled is indirectly controlled by controlling the temperature of a cooling fluid. In this case, it is an object of the present invention to provide a method and an apparatus for controlling a temperature of an object to be cooled by a fluid capable of uniformly cooling such that excessive cooling or insufficient cooling does not occur.

It is another object of the present invention to provide a method and an apparatus for controlling the temperature of a cooled object by using a fluid in which the temperature of each cooled object can be appropriately maintained at a target value.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a plurality of objects to be cooled having a cooling passage through which a cooling fluid flows are circulated by a cooling pump having a variable flow rate. A temperature control method for maintaining a predetermined target temperature while cooling with a cooling fluid, comprising: a temperature of a cooling fluid at an inlet side and an outlet side of a cooling passage of each of the cooled bodies; and a cooling fluid flowing through each of the cooled bodies. Measure the flow rate, assuming an appropriate target temperature for each cooled object based on the measured temperature and flow rate, the inlet temperature of the cooling fluid distributed to each cooled object based on the appropriate target temperature or Determine the target value of the flow rate, by controlling the flow rate at the outlet side of each cooled object, so that the inlet temperature or the flow rate of the cooling fluid to be distributed to each cooled object becomes the target value, Each cooled object It is characterized in that to keep the temperature within the appropriate target temperature.

According to a fourth aspect of the present invention, a plurality of objects to be cooled having a cooling passage through which a cooling fluid flows are maintained at a predetermined target temperature while being cooled by cooling water circulated by a variable flow rate type cooling pump. A temperature control device, comprising: a first temperature detector disposed on a cooling passage outlet side of each of the cooled objects; and a flow control valve disposed on a cooling passage outlet side of each of the cooled objects. A flow meter disposed on a cooling passage outlet side of each of the objects to be cooled; a cooler for cooling a cooling fluid discharged from the cooling pump; and a second cooler disposed on an outlet side of the cooler. 2, a third temperature detector disposed at the suction port of the cooling pump, and a temperature measured by the first temperature detector and the second temperature detector and a flow rate measured by the flow meter. Appropriate for each cooled object based on Calculating means for assuming a target temperature and determining a target value of an inlet temperature or a flow rate of a cooling fluid to be distributed to each object to be cooled based on the appropriate target temperature; and cooling to be distributed to each object to be cooled. Flow rate control means for controlling the flow rates of the flow control valves of the respective cooled objects so that the inlet temperature or the flow rate of the working fluid becomes the target value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method and an apparatus for controlling the temperature of an object to be cooled by a fluid according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a view showing an apparatus for carrying out a temperature control method according to the present invention. As in FIG. 2, cooling oil is supplied by using a main shaft 1 of a machine tool and ball screws 2a and 2b of a feed shaft as cooling objects. Cooling is performed by circulating with a cooling pump 4 of a variable capacity type.

The cooling pump 4 sends the cooling oil sucked from the reservoir tank 3 to the cooler 5, where the cooling oil is cooled and then distributed to the main shaft 1, the ball screws 2a, 2b.
In this case, the pipe downstream of the cooler 5 is a cooling pipe 20a,
20b, and the cooling piping is a ball screw 2a,
It branches to cooling pipes 21a and 21b which send cooling oil to 2b.

The cooling oil introduced into the main shaft 1 from the cooling pipe 20 a flows through the oil jacket 7 to cool the main shaft 1, and is then led out to the cooling pipe 22. On the other hand, the cooling pipe 21
Cooling oil introduced from a and 21b into the ball screws 2a and 2b respectively flows through a cooling passage extending in the axial direction, and is led out to the cooling pipes 23a and 23b. The cooling pipe 22 and the cooling pipes 23a and 23b join to form a return pipe 24,
The cooling oil is returned to the reservoir tank 3.

In this embodiment, the main shaft 1, the ball screw 2
pipes 22, 23a, 23b on the outlet side of the cooling passages a, 2b
Have the first temperature sensors 25a to 25c and the flow meter 26
a to 26c and flow control valves 27a to 27c are provided.

On the other hand, on the outlet side of the cooler 5, a second temperature sensor 28 is provided.
Thus, the temperature of the cooling oil on the inlet side of the main shaft 1 and the ball screws 2a and 2b is measured. Further, a third temperature sensor 29 is provided at the suction port of the cooling pump so that the temperature of the cooling oil at the suction port can be measured.

In FIG. 1, reference numeral 30 denotes a control device, which controls the temperature data of the cooling oil measured by the first temperature sensors 25a to 25c, the second temperature sensor 28, and the third temperature sensor 29. Alternatively, the flow rate data measured by the flow meters 26a to 26c is taken in, a predetermined calculation is performed, and the flow control valves 27a to 27c and the cooler 5 are controlled as described later. Further, the control device 30
The rotation speed of the cooling pump 4 is controlled via the inverter unit 31. Note that a servo unit may be used instead of the inverter unit 31 for controlling the rotation speed of the cooling pump.

Hereinafter, the contents of the temperature control will be described in detail. The cooling oil discharged from the cooling pump 4 is supplied to the cooler 5
And then distributed to the main shaft 1 and the ball screws 2a and 2b. When the cooling oil passes through the main shaft 1 and the ball screws 2a and 2b, the main shaft 1 and the ball screws 2a and 2b are cooled.

Therefore, first, the temperature of the cooling oil is measured by the second temperature sensor 28 on the inlet side, and the temperature on the outlet side is measured by the first temperature sensors 25a to 25c. The flow rates of the cooling oil passing through the main shaft 1 and the ball screws 2a and 2b are measured by the flow meters 26a to 26c, respectively. The control device 30 calculates the flow rate of the passing cooling oil, the temperature on the inlet side, the temperature on the outlet side, and the heat capacity of the main shaft 1 and the ball screws 2a and 2b. Estimate the temperature of
An appropriate target temperature is assumed based on the estimated temperature. The appropriate target temperature is determined by the current spindle 1, ball screws 2a, 2b
In view of the estimated temperature and the temperature and flow rate of the cooling oil, the target temperatures are appropriate for maintaining the temperatures of the main shaft 1 and the ball screws 2a and 2b, respectively.

Next, the control device 30 calculates a target value of the flow rate of the cooling oil passing therethrough and a target value of the temperature on the inlet side of the cooling oil from the appropriate target temperatures obtained for each of the main shaft 1 and the ball screws 2a and 2b. decide.

Thereafter, the control device 30 compares the detected value of the flow rate taken from the flow meters 26a to 26a or the detected value of the temperature taken from the second temperature sensor 28 with the target value, and the detected value becomes the target value. Flow control valve 27a
The flow rate control is executed by adjusting the opening degrees of through 27c. By controlling the temperature or the flow rate of the cooling oil introduced into each of the main shaft 1 and the ball screws 2a and 2b to a target value, each of them is individually maintained at an appropriate target temperature, resulting in overcooling or insufficient cooling. Can be prevented.

In addition to the above-described temperature control, more appropriate temperature control may be performed by performing the operation control of the cooling pump 4 and the cooler 5 in parallel as follows.

That is, the control device 30 calculates the temperature of the cooling oil on the suction side detected by the third temperature sensor 29,
The appropriate rotation speed of the cooling pump 4 is determined, and the
The rotation speed of the cooling pump 4 is controlled to an appropriate rotation speed via. As a result, when the load on the machine increases and the temperature of the cooling oil that has passed through the main shaft 1 and the ball screws 2a and 2b suddenly rises, the cooling pump 4 Is corrected and the overall flow rate of the cooling oil is adjusted, so that the main shaft 1 and the ball screws 2a and 2b can be more accurately maintained within the appropriate target temperature.

Further, the control device 30 controls the third temperature sensor 2
An appropriate work amount of the cooler 5 may be determined from the temperature of the cooling oil on the suction side detected by the step 9, and the cooler 5 may be operated with this work amount. This makes it possible to correct the work amount of the cooler 5 in response to a rapid rise in the temperature of the cooling oil, and adjust the temperature of the cooling oil on the inlet side as a whole.

[0025]

As is apparent from the above description, according to the present invention, it is difficult to directly measure the temperature, and when controlling the temperature of a plurality of objects to be cooled indirectly by controlling the temperature of the cooling fluid. It is possible to perform uniform cooling such that excessive cooling or insufficient cooling does not occur, and it is possible to appropriately maintain the temperature of each cooled object at the target value.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a control device for implementing a method of controlling the temperature of a cooled object according to the present invention.

FIG. 2 is an explanatory diagram of a conventional temperature control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main shaft 2a, 2b Ball screw 3 Reservoir tank 4 Cooling pump 5 Cooler 25a to 25c First temperature sensor 26a to 26c Flow meter 27a to 27c Flow control valve 28 Second temperature sensor 29 Third temperature sensor 30 Control device 31 Inverter unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Asanome 2068-3 Ooka, Numazu-shi, Shizuoka Toshiba Machine Co., Ltd. (72) Inventor Yoshiaki Kai 3068 Ooka, Numazu-shi, Shizuoka Toshiba Machine F Terms (reference) 3L044 AA01 CA03 CA12 DB02 DD07 FA02 HA01 JA01 KA02 KA05

Claims (5)

[Claims] 1. A temperature control method for maintaining a plurality of objects to be cooled having a cooling passage through which a cooling fluid flows at a predetermined target temperature while cooling the plurality of objects with a cooling fluid circulated by a cooling pump having a variable flow rate. Measure the temperature of the cooling fluid at the inlet and outlet sides of the cooling passages and the flow rate of the cooling fluid flowing through each cooling target, and set an appropriate target for each cooling target based on the measured temperature and flow rate. Assuming a temperature, a target value of an inlet temperature or a flow rate of the cooling fluid to be distributed to each object to be cooled is determined based on the appropriate target temperature, and an inlet of the cooling fluid to be distributed to each object to be cooled. By controlling the flow rate at the outlet side of each cooled object so that the temperature or the flow rate becomes the target value, the temperature of each cooled object is maintained at the appropriate target temperature. Cooling body temperature Degree control method. 2. The temperature of the cooling fluid on the suction side of the cooling pump is measured, and the proper rotation speed of the cooling pump is determined from the temperature on the suction side of the cooling fluid. The method according to claim 1, wherein the number of rotations of the cooling pump is controlled such that: 3. A proper work amount of a cooler for cooling a cooling refrigerant is measured from a measured value of a temperature of a cooling fluid on a suction side of the cooling pump, and the proper work amount is determined. The method according to claim 1, wherein the cooler is controlled. 4. A temperature control device for maintaining a plurality of objects to be cooled having cooling passages through which a cooling fluid flows at a predetermined target temperature while cooling them with cooling water circulated by a cooling pump of a variable flow rate type. A first temperature detector disposed on the cooling passage outlet side of the object to be cooled; a flow control valve disposed on the cooling passage outlet side of each of the objects to be cooled; A flow meter disposed on a cooling passage outlet side; a cooler for cooling a cooling fluid discharged from the cooling pump; a second temperature detector disposed on an outlet side of the cooler; A third temperature detector disposed at a suction port of a pump, and an appropriate temperature for each object to be cooled based on the temperature measured by the first temperature detector and the second temperature detector and the flow rate measured by the flow meter. Assuming the target temperature, Calculating means for determining a target value of the inlet temperature or flow rate of the cooling fluid to be distributed to each cooling target based on the target temperature; and the inlet temperature or flow rate of the cooling fluid to be distributed to each cooling target is Flow rate control means for controlling a flow rate of a flow rate control valve of each of the cooled objects so as to reach the target value. 5. The rotation rate control means for controlling the rotation rate of a cooling pump for discharging a cooling medium so that the rotation rate becomes an appropriate rotation rate determined from the temperature of the cooling fluid suction port side. The temperature control device for a body to be cooled by a fluid according to claim 4, wherein the temperature control device has a fluid.