JPH0155939B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a processing device having a temperature control function.

As shown in FIG. 1, when machining a plurality of holes 4 and 5 on a workpiece W using a shaft head 15 equipped with multi-axis spindles 16 and 17, the machining hole pitch of the workpiece W is However, if the thermal expansion between the machined hole pitches of the workpiece W at the time of machining is not equal to the thermal expansion between the spindle pitches of the shaft head, there will be a small difference between the machined hole pitches at room temperature. This will result in dimensional errors.

In order to correct this dimensional error, conventionally, the temperature of the lubricating oil in the shaft head follows the temperature change of the cutting fluid, and machining is performed by making the amount of thermal expansion of the workpiece and the shaft head equal.

However, although this conventional device eliminates dimensional errors at a specific reference temperature, when the workpiece is assembled to a mating object at a room temperature different from the reference temperature after machining, thermal expansion occurs due to the temperature difference. , there was a risk that the assembly work would not be carried out smoothly.

In other words, if the standard temperature is 20℃, the room temperature will be 0 to 10℃ in winter, 30 to 40℃ in summer, and a maximum of 20℃.
A temperature difference around 0.degree. C. and an accompanying dimensional change will occur. This dimensional change may cause problems in the assembly work, even if the mating parts are made of the same material, but if they are made of different materials.

The present invention was made in order to eliminate such conventional problems, and its purpose is to change the temperature difference between the cutting fluid temperature and the lubricating oil temperature based on changes in room temperature, and to improve the temperature during assembly. This process involves machining workpieces to regular dimensions at near room temperature.

First, before explaining the embodiments of the present invention, the pitch error δ occurring in the workpiece W will be explained. 1st
In the figure, 15 is the shaft head for machining the workpiece W;
0 is a measuring device for measuring the pitch of the machined holes 4 and 5 of the workpiece W. In such a processing device, if the pitch of the holes 4 and 5 to be machined is l, and the coefficient of thermal expansion of the shaft head 15 is α, then the pitch lh of the spindles 16 and 17 when the shaft head temperature rises to th is , assuming that the spindle pitch is assembled to l at a predetermined assembly temperature to, it is expressed as lh = l [1 + α (th - to)], and the machined holes 4 and 5 of the workpiece W are at pitch lh
It will be processed into

On the other hand, when the cutting fluid temperature during machining of the workpiece W is tc, the workpiece W is maintained at this cutting fluid temperature tc during machining, but as soon as machining is completed, the workpiece W is at room temperature tr.
down to. Therefore, when the coefficient of thermal expansion of the workpiece W is β, the pitch lw of the machined holes 4 and 5 of the workpiece W at the time of measurement is lw=lt[1-β(tc-tr)]=l・[1+α(th −to)] [1−β(tc−tr)]

Further, the measuring device 50 is exposed to the same room temperature tr as the workpiece W. Therefore, when the coefficient of thermal expansion of this measuring device 50 is set to α, which is the same as that of the shaft head 15, the measuring shafts 51, 5
The pitch lm of 2 is the measurement axis 5 at the predetermined assembly temperature to.
Assuming that it is assembled to have a pitch l of 1.52, it is expressed as lm=l[1+α(tr-to)].

As a result, the pitch error δ is δ=lw−lm=l・[1+α(th−to)][1−β(tc
-tr)] -l[1+α(tr-to)] =l[α(th-tr]-β(tc-tr)-α・β(th-
to) (tc−tr)].

In the above formula, α and β have small values, so α and β
Omit terms that include. In this relational expression, if the pitch error δ is set to 0, the above equation can be expressed as 0=α(th-tr)-β(tc-tr). When this equation is further expressed as a relational expression between the room temperature tr and the lubricating oil temperature th, it is transformed into th=β/αtc−(β/α−1)tr (1).

Therefore, by calculating the theoretical lubricating oil temperature th using the above equation and making the actual lubricating oil temperature equal to this theoretical lubricating oil temperature, it is possible to eliminate the pitch error δ at room temperature tr.

Note that the room temperature tr changes slightly with the passage of time between processing, measuring, or assembling the workpiece W, but since the change in the room temperature tr is a change in the temperature over the course of a day, ℃, which is extremely small compared to the temperature difference between the reference temperature and the room temperature tr in summer and winter, and does not cause a large dimensional change that would cause problems during assembly.

A specific configuration of a processing device that prevents the pitch error δ from occurring under such room temperature tr will be described below.

10 is a processing device, 11 is a bed, 12 is a feed unit installed on the bed 11, 13 is a guide surface formed on this feed unit 12, and 14 is a slide slidably guided along the guide surface 13. Moving base, 1
5 is a shaft head installed on the sliding table 14, 16, 1
7 is a spindle rotatably supported on this shaft head 15; 18, 19 are spindles 16, 17;
20 is a gear box installed behind the shaft head 15 and rotatably connected to each spindle 16, 17; 21 is a drive motor connected to the input shaft of the gear box 20; 22 is a drive motor connected to the input shaft of the gear box 20; A jig main body installed on the bed 11 facing the shaft head 15, 23 a reference surface for positioning the workpiece, 24 a clamping device for clamping the workpiece, 25 a cutting fluid reservoir, 26 is the cutting fluid supply pump, 27 is the pump 26
29 is a return pipe for recovering the cutting fluid supplied to the workpiece, and 30 is the cutting fluid that is returned through the return pipe 29. A temperature sensor for detecting temperature; 31 is a storage tank for lubricating oil to be supplied to the shaft head 15; 32 is a lubricating oil supply pump; 33 has one end communicating with the supply pump 32 and the other end communicating with the shaft head 15; 34 is a return pipe that returns the lubricating oil discharged from the shaft head 15 to the storage tank 31, 35 is a heater that heats the lubricating oil, 36 is a cooler that cools the lubricating oil, and 37 is a heater. 34 and a control circuit for controlling the operation of the cooler 35;
A temperature detector 44 detects the temperature of the lubricating oil returned to 1, and a temperature detector 44 detects the room temperature tr.

The control circuit 37 controls the temperature of the cutting fluid detected by the temperature detectors 30, 38, and 44 as shown in FIG.
an arithmetic circuit 40 that calculates tc, lubricating oil temperature th, and room temperature tr based on equation (1); and this arithmetic circuit 4.
A stop circuit 4 that turns on and off the power to the heater 35 and the cooler 36 according to a control signal output from 0
It's more familiar than 3.

In the above configuration, the arithmetic circuit 40 receives the temperature detectors 30, 38, and 44 from the cutting fluid temperature tc and the lubricating oil temperature.
th, room temperature tr are input, and the relationship between these three is expressed as (1) above.
For example, when the room temperature Tr changes, the calculation circuit 40 detects that an imbalance has occurred in the relationship in equation (1) as a result of the calculation, and changes the lubricating oil temperature.
Outputs a signal to change th. Normally, the lubricating oil temperature th is set higher than the cutting fluid temperature tc, and if the room temperature tr rises under such conditions, the cutting fluid temperature tc and the lubricating oil temperature th will change, as is clear from equation (1) above. The cooler 36 is operated to lower the lubricating oil temperature th so that the temperature difference between
Further, when the room temperature tr decreases, the heater 35 is operated so that the temperature difference becomes larger, and the lubricating oil temperature th is increased.

By controlling the lubricating oil temperature th so as to satisfy equation (1) above as the room temperature tr changes, the machined holes 4 and 5 of the workpiece W can be made to have the regular pitch l at the room temperature tr. It can be processed into

As described above, the processing apparatus of the present invention can be operated at room temperature,
A temperature adjustment device for lubricating oil that detects the cutting fluid temperature and lubricating oil temperature, calculates the theoretical lubricating oil temperature based on this room temperature and cutting oil temperature, and adjusts the actual lubricating oil temperature so that it approaches the theoretical lubricating oil temperature. Since the structure is such that the operation of the workpiece is controlled, the workpiece is machined at room temperature without any dimensional errors, and the effect of smooth assembly etc. can be obtained. Furthermore, since the configuration is such that only the temperature adjustment device on the lubricating oil side is controlled, the configuration is simplified and control becomes easier.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the relationship between the shaft head, a measuring instrument, and a workpiece, FIG. 2 is a diagram showing the overall configuration of the processing device, and FIG.
The figure is a block diagram of the control circuit. 10...Processing equipment, 11...Bed, 12...
Feed unit, 14...Sliding table, 15...Shaft head, 16, 17...Spindle, 18, 19...
Processing tool, 22... jig body, 23... reference surface,
24... Clamp device, 25... Cutting fluid reservoir,
27... Cutting fluid ejection nozzle, 30... Temperature detector, 31... Lubricating oil reservoir, 35... Heater, 3
6... Cooler, 37... Control circuit, 38... Temperature detector, 44... Temperature detector, W... Workpiece.

Claims (1)

[Scope of Claims] 1. A processing device that processes a workpiece by supplying cutting fluid to a processing location, including a circulation device that circulates lubricating oil within the shaft head of the processing device, and a circulation device that heats or cools the lubricating oil. a temperature adjustment device that adjusts the temperature of the lubricating oil, the temperature of the lubricating oil, and the temperature of the cutting fluid;
A lubricating oil temperature sensor, a cutting fluid temperature sensor, and a room temperature temperature sensor that detect tc and room temperature tr, respectively, and a lubricating oil temperature sensor, a cutting fluid temperature sensor, and a room temperature temperature sensor that detect Input the detection signal and calculate the theoretical lubricating oil temperature th based on the relational expression th = β / αtc - (β / α - 1) tr (β is the coefficient of thermal expansion of the workpiece, α is the coefficient of thermal expansion of the shaft head). A processing device having a temperature control function, characterized in that it is provided with a control means for calculating and controlling the temperature adjusting device to bring the actual lubricating oil temperature closer to the theoretical lubricating oil temperature.