JPH0740186A - Device for restricting thermal displacement of main spindle - Google Patents

Abstract

PURPOSE:To provide a device for restricting thermal displacement of a main spindle, which utilizes a main spindle cooling device provided in a machine tool to warm up the main spindle easily, without requiring a special temperature control mechanism in a machine tool by providing a coolant return temperature detector. CONSTITUTION:Operation control of a main spindle cooling device 10 is performed by comparing a coolant return temperature detector T1 for detecting the temperature of the coolant returning to a cooling unit 11 with a temperature generator TS or a machine body or room temperature detector SR so as to operate the device at the only time when the temperature value of the coolant return temperature detector T1 is higher than a value of the detector TS or SR. During the operation of a machine, the operation is switched to the machine or room temperature detector, and during the stop of the operation of the machine, the operation is switched to the temperature generator TS and the coolant return temperature detector T1 for comparison to control the operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not require a special temperature control mechanism in a machine tool, but utilizes a spindle cooling device equipped in the machine tool to easily heat-displace the spindle. The present invention relates to a suppression device.

[0002]

2. Description of the Related Art Conventionally, when a spindle of a machine tool is started from a stopped state, heat generation of a bearing causes thermal expansion of the spindle, which results in relative displacement between a workpiece and a tool. To prevent this effect and perform high-precision machining,
A reliable method is to wait for the thermal displacement to saturate before starting processing. However, in this method, the time to saturate varies depending on the machine, and there are cases where warm-up operation for several hours is required.

As a countermeasure against this, it is sufficient to warm the spindle at all times even when the spindle is stopped, but a temperature control device using a heater or the like is required, which not only wastes heat energy but also returns it by diverging it. There is a problem of increasing the thermal displacement of the entire machine.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to solve the problems.
An object of the present invention is to provide a thermal displacement suppressing device for a spindle that simply heats the spindle by using a spindle cooling device equipped in the machine tool without requiring a special temperature control mechanism in the machine tool.

[0005]

According to the present invention, a spindle cooling device is provided in a spindle, and operation control of the spindle cooling device is performed by a refrigerant return temperature detector to a cooler, a temperature generator or a fuselage, or a room temperature. According to the comparison with the detector, the operation is performed only when the temperature value of the refrigerant return temperature detector exceeds, and the machine or room temperature detector side is set while the machine is running, and the temperature generator side and the refrigerant are set when the machine is stopped. It is a thermal displacement suppressing device for a main shaft, which is characterized by switching and controlling a return temperature detector.

[0006]

According to the present invention, while the machine is stopped, the refrigerant return temperature detector of the cooler of the spindle cooling device is compared with the temperature generator, and when the return oil temperature becomes higher than the set value, the cooler is activated. Match the return oil temperature to the set value. Further, when the return oil temperature becomes higher than the set value as compared with the side of the machine body or the room temperature detector during the operation of the machine, the cooler is operated to control the return oil temperature to match the set value. Thus, the warm air of the spindle is kept warm by the half-heating of the refrigerant by the circulation pump of the spindle cooling device, the temperature does not rise excessively, and safe and no electric power for warming is required. Further, since it is simply installed in the temperature input section of the spindle cooling device, the spindle warm-up system is simply realized.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments shown in the drawings will be described below. Figure 1
Is a system diagram showing a spindle warm-up system according to the present invention, and FIG. 2 is a flow chart for explaining the operation of the spindle warm-up system according to the present invention.

In FIG. 1, in a spindle device S, a tool 2 is attached to the tip of a tapered hole of a rotary shaft 1, and a plurality of bearings B allow the rotary shaft 1 to be supported by a fixed main spindle cylinder 3. A jacket 4 for allowing a cooling liquid medium to flow is provided in a spiral shape on the outer circumference of the spindle cylinder 3, and the spindle cooling device 10 is cooled by two places 5A and 5B of an outer cylinder body 5 which encloses the jacket 4 and a pipe 6. It is connected to the container 11 and the circulation pump 12.
The operation of the cooler 11 is governed by the cooler control circuit 13. The refrigerant return temperature detector T1 and the airframe or room temperature detector T2 or temperature generator TS are NC in this circuit.
The sensor switching command SR from the controller 20 selectively switches the sensor switching relay SR.

That is, when the machine tool is stopped, the sensor switching relay SR selects the temperature generator TS, and this set dial value is compared with the detected temperature value of the refrigerant return temperature detector T1 to return the return oil. When the temperature is high, the cooler 11 is activated. Also, when the machine tool is operating, the sensor switching relay SR
Selects the airframe or the room temperature detector T2, and compares the set dial value with the detected temperature value of the refrigerant return temperature detector T1. When the return oil temperature is high, the control system is operated to operate the cooler 11. Constitute.

The operation of the main shaft thermal displacement suppressing device will be described with reference to FIG. The NC control device 20 determines whether the "start" of the function is "machine stop of machine tool (main spindle stop)" (a).
Monitor, and if it is in a stopped state, "sensor switching" (b)
To select the temperature generator TS. This set dial value,
The detected temperature value of the refrigerant return temperature detector T1 is compared, and "return oil temperature is high" (d) and "cooler is activated".
(F) Let me. On the other hand, "the return oil temperature is low"
(D) and “Stop the cooler” (f), and then click “Servo OF
Look at the state of "F". Here, "servo OFF"
If it is not (h), the NC controller 20 monitors again whether or not "machine stop of machine tool (main spindle stop)" (ii), and the same operation is repeated. "Servo OFF"
If (h) is shut down, "END"
(Re)

On the other hand, the NC control unit 20 monitors whether or not "machine stop of machine tool (main spindle stop)" (a),
If it is an operating state, select the airframe or room temperature detector T2 in "Sensor / standard state" (C). This measured value is compared with the detected temperature value of the refrigerant return temperature detector T1,
"Returned oil temperature is high" (e) and "cooler operation" (f)
Let On the other hand, "return oil temperature is low" (e) and "cooler is stopped" (f), "servo OFF" (h)
See the state of. Here, if the "servo is off" (h), it is monitored again by the NC controller 20 whether it is "machine stop of machine tool (main spindle stop)" (a).
The same action is repeated. If the "servo is off" (h) shutdown, then "END" (re).

That is, the temperature data input to the spindle cooling device is input from the temperature generator TS only when the machine is stopped. Then, when the machine is in operation, it is switched to a normal machine or room temperature sensor, and the control of the temperature of the refrigerant returned from the main shaft is maintained at a predetermined temperature value by operating / stopping the cooler.

It is needless to say that the present invention is not limited to the above-mentioned respective embodiments, and that design changes can be further made within the scope of the invention. For example, it is applied to both vertical and horizontal machine tools.

[0014]

[Effects] Since the present invention is configured as described above, when the machine is stopped, the refrigerant return temperature detector of the cooler of the spindle cooling device and the temperature generator are compared, and when the return oil temperature becomes higher than the set value, Adjust the return oil temperature to the set value by operating the cooler, and
During operation of the machine, when the return oil temperature becomes higher than the set value as compared with the airframe or the room temperature detector side, the cooling oil is operated to control the return oil temperature to the set value. Thus, the warm air of the spindle is kept warm by the half-heating of the refrigerant by the circulation pump of the spindle cooling device, the temperature does not rise excessively, and safe and no electric power for warming is required. Further, since it is simply installed in the temperature input part of the spindle cooling device, there is an effect that the spindle warm-up system is simply realized.

[Brief description of drawings]

FIG. 1 is a system diagram showing a spindle warm-up system according to the present invention.

FIG. 2 is a flow chart for explaining the operation of the spindle warm-up system according to the present invention.

[Explanation of symbols]

 1 rotary shaft 2 tool 3 spindle cylinder 4 jacket 6 piping 10 spindle cooling device 11 cooler 12 circulation pump T1 refrigerant return temperature detector T2 airframe or room temperature detector TS temperature generator SR sensor switching relay C sensor switching command

Claims (1)

[Claims] 1. A spindle cooling device is provided on a spindle, and operation control of the spindle cooling device is performed by comparing a refrigerant return temperature detector to a cooler with a temperature generator or a fuselage or a room temperature detector. Do not operate only when the temperature of the return temperature detector exceeds the temperature value.While the machine is operating, set it to the machine or room temperature detector side, and switch to the temperature generator side and refrigerant return temperature detector when the machine is stopped. A thermal displacement suppressing device for a spindle, which is characterized by performing a running control.