JPH04164547A - Working machine - Google Patents

Abstract

PURPOSE:To improve the working accuracy by forming a pipeline where a liquid of a designated temperature is supplied in a structure within a plane intersecting the longitudinal direction of a structure. CONSTITUTION:A pipeline 10 for circulating cooling oil is formed in a thermal interrupting portion 9 formed at the lower end of a column 4, cooling oil of a designated temperature is poured from an inlet 11 of the pipeline 10 to make a circuit in the interior of the column 4 and discharged from an outlet 12. Similarlly, a thermal interrupting portion 13 is formed also in a little upper position of the middle of the column 4. Further, a thermal interrupting portion 14 is formed also near the end portion of a head 5, which is connected and supported on the column 4, and a thermal interrupting portion 15 is formed also on the root portion of a spindle head 6 projected on the lower portion of the forward end of the head 5. Cooling oil of the same temperature is circulated in each interior of the thermal interrupting portions 13-15. Thus, the deformation due to heat generation of the whole structure can be held down so as to improve the working accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to processing machines such as machining centers, lathes, and press molding machines.

(Conventional technology) With processing machines such as machining centers, when trying to improve the processing accuracy and perform ultra-precision processing, the obstacles are heat generation from the workpiece and processing tools during processing, and This is heat generated from a drive source such as a motor installed in the machine. This heat generation increases the temperature of the workpiece and processing tool, causing thermal expansion, and is also transmitted to the structure of the processing machine itself that supports the workpiece and processing tool, causing thermal expansion as well. bring about When these thermal displacements occur, if the entire processing machine expands at a similar rate at the same time, there will be no problem because the relative position between the workpiece and processing tool will not change and will remain in its normal state. However,
In reality, the displacements caused by thermal expansion of each part vary, resulting in deviations in the relative positions of the workpiece and the processing tool.

The model in FIG. 8 conceptually shows the mechanism, including this thermal expansion, that inhibits the improvement of precision of processing machines.

The figure shows a case where a tool (processing tool) processes a workpiece (workpiece) in a machining center.

In order to keep the tool and workpiece in a predetermined relative position, the tool holder, spindle, gear group, head, head feeder, column, base, saddle feeder, saddle, and table are arranged in order from the tool to the workpiece. A continuous structure is composed of the feeding device, table, and fixture. The whole of these continuous structures can be thought of as a C-frame, with the tool and workpiece each being cantilevered at either end of the C-frame.

In this illustrated model, the heat generated by the motor at the top of the head and the group of gears that transmit its rotation to the main shaft, as well as the machining heat generated between the tool and the workpiece, are sequentially transmitted to the adjacent structure. When the temperature of these heat generating parts and the respective structural parts to which heat is transferred increases, thermal expansion occurs and the shape of the C-shaped frame is deformed. At this time, each part of the C-shaped frame does not have a uniform temperature distribution due to the presence or absence of heat generation and the amount of heat transferred from other parts, and the expansion rate of each part differs, resulting in the overall shape of the C-shaped frame It becomes something fun.

Moreover, when machining is started, opposing machining reaction forces are generated in the tool and the workpiece, and are transmitted to the entire C-shaped frame from both ends. As a result, each part of the C-shaped frame receives an external force such as a bending moment depending on the magnitude of the processing reaction force, and undergoes elastic deformation.

In this case, even if each part of the C-shaped frame is subjected to a bending moment like -, each part has a different rigidity, so the amount of deformation that occurs in each part is different, and the shape of the entire C-shaped frame after deformation is complicated. Become something.

As a result of the combination of thermal expansion and elastic deformation, which have different displacement rates for each local area, a shift occurs in the relative position of the tool at the tip of the C-shaped frame and the object to be split. These relative positional deviations can be reduced by installing cooling devices in the heat generating parts of each part or by increasing the rigidity of each structural part. However, when trying to further improve machining accuracy,
These generated displacements become a major obstacle.

Therefore, in order to fundamentally solve these problems, we use various sensors to detect the temperature, machining reaction force, and deformation of each part of the C-shaped frame, and indirectly estimate the amount of relative positional deviation between the tool and the workpiece. The inventor of the present application has proposed a device for correcting the relative positional deviation by NC based on the obtained value, or forcibly correcting the deformation by providing an actuator in the C-shaped frame. No. 198479, ``Attitude Control Device for Machine Tools,'' and ``Processing Machines,'' filed on September 26, 1990.

By using these proposed solution methods, it is possible to obtain the desired machining dimensional accuracy. In particular, regarding the correction of machining reaction force, the value of machining reaction force and the amount of deformation generated by the tool and workpiece at the start of machining are detected, and the feed amount of the x, y, and z axes is instantly corrected using NC software. Control with good responsiveness is possible.

Similarly, a temperature sensor detects temperature changes in each part of the C-frame due to heat generation, and a displacement sensor detects deformation due to temperature rise. From these detected values, the shape change of the C-frame is comprehensively estimated and the actuator is activated. activate it,
It is possible to return the values 1 at both ends of the C-shaped frame to their normal positions.

The model shown in Fig. 8 is similar to a press forming machine, for example, in which the processing tools are arranged at both ends of a C-shaped frame or a gate-shaped frame, and the processing tools are moved while moving the relative positions of the processing tools to a predetermined interval. This also applies to processing machines that process workpieces placed between them.

In that case, both ends of the C-shaped frame shown in the figure will be used as processing tools, and a mechanism for moving the processing tools to a predetermined position will be required.

(Problem to be Solved by the Invention) By the way, in order to accurately grasp the shape change of the entire C-shaped frame, it is necessary to accurately detect the amount of displacement for each component, especially due to temperature changes in the C-shaped frame. As for displacement, the amount of heat generated by each heat source changes irregularly depending on the machining situation, and the transmission of that heat to each component also shows a very complicated aspect, so it cannot be estimated by just assuming a simple model. It is difficult to accurately grasp the amount of displacement. Therefore, it is necessary to actually accurately measure the displacement of each part, and a large number of uniform displacement sensors must be installed in each part.

However, in actual machine tools and the like, there are restrictions on the arrangement, operation, space, wiring, etc. of each structural part, and it is not always possible to install a sufficient number of displacement sensors.

Therefore, in areas where there was no room to install a displacement sensor, a temperature sensor, which is smaller than the displacement sensor, was installed to estimate the amount of displacement based on the overall temperature distribution. In this way, displacement sensors are used for areas where the amount of displacement can be directly detected, and temperature distribution is detected using temperature sensors for areas that cannot be directly detected, and these values are combined to understand and correct changes in the overall shape of the C-shaped frame. I started processing. Therefore, in order to obtain the amount of displacement for each component from the detected temperature distribution, it is necessary to set various conditions in advance, measure the correspondence between the temperature distribution and the generated displacement, and store it as data. .

By collecting these data as highly accurate values as possible, the actuator can be operated precisely for the first time, and the tool and the object to be split at the tip of the C-shaped frame can be corrected with high precision.

Although the methods proposed in this way are capable of highly accurate correction, there is a problem in that the collection of data required for this is cumbersome.

Therefore, in order to simplify the control for correcting the thermal displacement that occurs in each part of the entire C-shaped frame, it is necessary to lower the upper limit of the amount of thermal displacement that occurs in the C-shaped frame as much as possible and to control the thermal displacement range that is subject to control. It would be better to reduce the amount of collected data by making it smaller.

Even if displacement sensors and temperature sensors are installed in this way, if the temperature change itself in each part is large, the amount of correction will be large, and as a result, it will be difficult to ensure the desired accuracy. The same applies to a processing machine that supports a tool and a processing tool and processes a workpiece placed between the two processing tools.

The present invention has been made with attention to these points, and its purpose is to eliminate relative positional deviation between a processing tool and a workpiece, or between a processing tool and a processing tool in a processing machine. The object of the present invention is to provide a processing machine in which thermal displacement generated in a processing tool and a workpiece or a structure supporting between the workpiece and the processing tool is reduced.

(Means for Solving the Problems) In order to achieve the above object, a first invention provides a method for moving a processing tool and a workpiece supported by a continuous structure so that their relative positions can be changed at specified relative positions. A processing machine in which a processing tool processes a workpiece while maintaining the temperature of the workpiece is characterized in that a conduit through which fluid at a predetermined temperature is supplied is formed in the structure in a plane intersecting the longitudinal direction of the structure. .

The second invention is a processing machine that moves a processing tool supported by a continuous structure to a specified relative position and processes a workpiece placed between the processing tool and the processing tool. The structure is characterized in that a conduit through which fluid at a predetermined temperature is supplied is formed in the structure in a plane intersecting the longitudinal direction of the structure.

(Function) In the first and second inventions, when a fluid at a predetermined temperature is supplied to the pipe formed in the structure in a plane intersecting the longitudinal direction of the structure, the structures before and after the pipe are heated. The temperature will be approximately the same as the supply fluid.

In addition, if the temperature of one or both of the structures before and after the pipe increases due to heat generation or heat transfer, the part of the structure near the pipe will absorb heat and be cooled by the supply fluid, and the temperature will be close to that of the supply fluid. Heat is not transferred to the structure on the opposite side of the pipe.

As a result, the structures before and after the surface on which the conduit is formed are thermally insulated from each other, and no heat is exchanged between the front and rear surfaces.

(Example) The present invention will be described in detail below with reference to the drawings.

Figure 1 shows a first example in which the first invention is applied to a machining center.
FIG. 2 is an external view showing an example.

In the figure, a table 2 that is movable on a horizontal plane is provided on the upper right side of the base l, and the workpiece 3 is placed on the table 2.
fixed on top. On the other hand, a column 4 is installed on the upper left side of the base 1, and a head 5 is attached to the upper right side of the column 4 so as to be vertically movable. A spindle rod 6 is provided at the lower end of the head 5 to pivotally support the spindle 7. A processing tool 8 is attached to the spindle 7 to cut a workpiece 3 fixed to the table 2 below.

That is, in this machining center, the processing tool 8 that performs processing and the workpiece 3 that is processed are supported in a C shape by each component.

FIG. 2 is a sectional view taken along line 1--2 in FIG. 1, and FIG. 3 is a sectional view taken along line m--2 in FIG.

As shown in FIGS. 2 and 3, the column 4 has a hollow box-like structure, and a heat shielding part 9 is formed at the lower end of the column 4. As shown in FIGS. The heat shielding part 9 has a thick wall on the inside of the column 4, and has a pipe line 10 for circulating cooling oil. Cooling oil at a predetermined temperature is injected from the inlet 11 of the pipe 10, circulates around the inside of the column 4, and then is discharged from the outlet 12.

The circulating cooling oil is circulated by an oil cooler, etc. (not shown).
Maintained at a specified temperature. The predetermined temperature of the cooling oil referred to here is a temperature comparable to the atmosphere in which the machining center is installed.

Similarly, a heat shielding part 13 is also formed at a position slightly above the middle of the column 4.

Furthermore, the head 5 also has a hollow box-shaped structure, and a heat shielding part 14 is formed near the left end connected to and supported by the column 4. Further, a heat shielding portion 15 is also formed at the root portion of the spindle head 6 protruding from the lower end of the head 5 .

The internal structure of the heat cutoff parts 13 to 15 formed in each part is almost the same as that of the heat cutoff part 9, and cooling oil of the same temperature circulates inside each part.

Here, part of the processing heat generated when the processing tool 8 processes the workpiece 3 increases the temperature of the processing tool 8 and is transmitted to the spindle 7, the spindle to the rad 6 in order, and the spindle 7 and the spindle head 6. increase the temperature. Each part expands and increases in size as the temperature rises.

However, since the heat shielding part 15 is provided between the spindle head 6 and the head 5, heat is not transferred from the spindle head 6 to the head 5 side.

Further, inside the head 5, there is a motor that drives the spindle 7 and a gear group for transmitting the rotation thereof (not shown), so that heat is generated while the spindle 7 is being driven.

This heat generation increases the temperature of the spatula 5, but the heat is not transferred to the spindle head 6 side because there is a heat cutoff part 15. Similarly, there is a heat cutoff part 14 to the column 4 side, so the heat is not transferred to the spindle head 6 side. Furthermore, since the column 4 also has a heat shielding part 9 at the boundary with the base l and a heat shielding part 13 at the top, even if there is a temperature fluctuation in the column 4 or the base l, heat transfer between them will not occur. do not have.

In the machining center of the embodiment, a plurality of heat shielding parts are installed in the plane perpendicular to the support direction of the C-shaped frame that supports the processing tool 8 and the workpiece 3, so that the heat generated in each part is separated from the other parts. The occurrence of thermal displacement due to heat generation is limited to only a specific section. As a result, deformation of the entire C-shaped frame structure is kept small, the amount of relative positional deviation between the workpiece 3 and the processing tool 8 is reduced, and processing accuracy is improved.

In other words, if the C-shaped frame that supports the processing tool 8 and the workpiece 3 is divided into a plurality of parts by thermal insulation parts perpendicular to the support direction as shown in the embodiment, each structural part is thermally isolated from other structural parts. Even if heat is generated within a specific section, the temperature rise and thermal expansion due to the heat generation will remain within that section.
Other sections are not affected at all, and as a result, the location where deformation of the C-shaped frame occurs due to heat generation is limited, and the amount of deformation that occurs in the entire C-shaped frame also becomes a small value.

Moreover, if you try to accurately understand the shape change of the entire C-shaped frame by referring to the temperature distribution, as in the above-mentioned processing machine that the present inventor has already proposed, it is possible to With this configuration, the location where thermal displacement occurs is limited to a specific component, making it easier to construct a control model.

Of course, even with conventional processing machines that do not have a control device that corrects minute displacements of the structure, by configuring the structure as in the example, the relative positional deviation between the workpiece and the processing tool can be corrected. The amount is reduced and processing accuracy is improved.

The location and number of heat shields to be installed will depend on the physical structure of the applicable processing machine, the amount of heat generated by each heat source, the heat transfer characteristics of each part, etc. Furthermore, the heat absorption capacity of the heat shield to be installed and the required It is determined by taking into consideration machining accuracy and the like.

FIG. 4 is an external view showing a second embodiment in which the first invention is applied to a lathe.

In the figure, a headstock 22 is provided at the upper left side of the bed 21, and a spindle head 24 that projects from the upper right side pivotally supports a spindle 25. The spindle 25 grips the workpiece 23 by tightening the chuck 26 . When the workpiece 23 is long, the other end of the workpiece 23 is supported by a tailstock shaft 28 that is supported by a support shaft 27 .

A reciprocating stand 29 is supported at the upper center of the bed 21 so as to be movable left and right, and as the tool rest 30 installed on the upper part moves back and forth, the cutting tool 31 attached to the tool rest 30 rotates. The workpiece 23 is cut.

In this lathe as well, like the machining center described above, a cutting tool 31 that performs machining and a workpiece 23 to be machined are supported in a C shape by each component.

In addition, each of the component parts, such as the head 21, headstock 22, spindle head 24, Shinshindai 27, and carriage 29, has a hollow box or cylindrical shape, and has a longitudinal end at each end or middle part. Heat shielding portions 32 to 38 are formed perpendicularly to the direction.

The heat cutoff parts 32 to 38 have almost the same structure as the heat cutoff part 9 etc. installed in the machining center shown in FIG.
Cooling oil of the same temperature is circulated in each to prevent heat from being transferred between the front and back. In this manner, as in the case of the machining center described above, the heat generated during machining is prevented from being transmitted to the bed 21 and the headstock 22 by providing the heat cutoff sections 36 to 38.

Further, the motor that drives the spindle 25 is located inside the bed 21 on the left side of the heat cutoff section 33 (not shown), and the gear box that changes the speed of the rotation is heat cut off from the heat cutoff section 33 located above the motor (also not shown). It is housed inside the headstock 22 between the main spindle 34 and the main spindle 22 . These heat waves are generated by the heat cutoff section 33 and the heat cutoff section 34, or the heat cutoff section 3, respectively.
4 and the heat shielding part 35, the heat is prevented from being transmitted to other parts.

In this way, the lathe of the embodiment has a workpiece 23 and a hide 31.
By installing multiple heat shielding parts in a plane perpendicular to the supporting direction of each part of the C-shaped frame that supports the Since it is limited to only a specific section, deformation of the entire C-shaped frame structure due to heat generation can be kept small.

As a result, the amount of relative positional deviation between the workpiece 23 and the cutting tool 31 is reduced, and processing accuracy is improved.

FIG. 5 is an external view showing a third embodiment in which the first invention is applied to a machining center having a portal structure.

This portal-shaped machining center is a symmetrical combination of the C-shaped frame structures of the machining center shown in FIG.

In the figure, a table 42 that is movable on a horizontal plane is disposed at the upper center of a base 41, and a workpiece 43 is fixed on the table 42. On the other hand, columns 44.45 are installed on both sides of the base 41, and columns 44.45 are installed on both sides of the base.
A head 46 is attached to the upper inner side of 45. A spindle rod 47 is provided at the bottom of the head 46 and pivotally supports the spindle 48. A processing tool 49 is attached to the spindle 48 to cut a workpiece 43 fixed to the table 42 below.

Heat shielding parts 51.52 are formed inside the installation positions of the columns 44.45 on both sides of the base 41.

In addition, the columns 44 and 45 have heat shielding parts 53 and 54 formed at the lower end of the boundary with the base 41, and furthermore, heat shielding parts 55 and 56 are formed in front of the installation position of the helad 46 at the upper end. Ru.

Further, heat shielding portions 57.58 are also formed at the boundary between the column 44.45 and the helad 46.

Each of these heat cutoff parts 51 to 58 has substantially the same structure as the heat cutoff part 9 and the like described above.

In the case of this embodiment as well, since the heat generated in each structural part is prevented from being transmitted to other parts, it is possible to minimize the reduction in processing accuracy due to the occurrence of thermal displacement.

No. 6FgJ is an external view showing an embodiment in which the second invention is applied to a press molding machine.

This press molding machine has the same overall structure as the portal-shaped machining center shown in FIG. 5, except for the processing section.

In the figure, at the upper center of the base 71 is a guide fixing base 72.
is arranged, and a diamond 3 as a processing tool is fixed to the upper surface thereof. On the other hand, columns 74.7 are provided on both sides of the base 71.
5 is installed, and a head 76 is installed inside the upper part of the column 74,75. A ram 77 that moves up and down is supported at the bottom of the head 76. A punch 78, which is a processing tool, is attached to the ram 77, and plastically works a workpiece 79 set between the ram 77 and the diamond 3 below.

Heat shielding parts 81.82 are formed inside the installation positions of the columns 74.75 on both sides of the base 71.

In addition, the columns 74 and 75 have heat-blocking parts 83 and 84 formed at the boundary with the base 71 at the lower end, and heat-blocking parts 85 and 86 at the top in front of the installation position of the head 76, respectively. .

Further, heat shielding portions 87.88 are also formed at the boundary between the column 74.75 and the head 76.

Each of these heat cutoff parts 81 to 88 has substantially the same structure as the heat cutoff part 9 and the like described above.

In the case of this embodiment as well, since the heat generated in each structural part is prevented from being transmitted to other parts, the distance between the two when the diamond 3, which is a processing tool, descends and comes closest to the punch 78, which is also a processing tool. Fluctuations in are suppressed to a minimum, making it possible to maintain high accuracy in machining dimensions.

FIG. 7 is a sectional view showing another embodiment of the heat cutoff section.

This heat shielding section is made by wrapping a ring-shaped heat exchange vibro 2 around the outer periphery of a component 61 such as a column having a box-shaped structure. In order to improve the amount of heat transferred between the heat exchange vibro 2 and the component 61, the inner part of the heat exchange vibro 2 that contacts the outer surface of the component 61 is made flat to increase the contact area.

By configuring the heat cutoff section in this way, it becomes possible to install the heat cutoff section at an arbitrary position, and it also becomes possible to relocate the heat cutoff section.

In this figure, the heat exchange vibro 2 is wound around the outside, but it can also be installed inside the component 61, and in particular, if it is installed from both sides, the heat shielding effect will be increased.

Further, the embodiment of the heat shielding part 9 shown in FIGS. 2 and 3 is as follows.
Although the number of passes of the conduit 10 is one, if possible from the viewpoint of processing and strength, a plurality of conduits 10 can be formed to increase the contact area of the cooling oil and increase the efficiency of heat exchange. Similarly,
The cross-sectional shape of the conduit IO can also be made other than circular, or grooves can be formed to increase the contact area and increase the amount of heat exchanged.

Furthermore, as the fluid to be passed through the pipe line 10, it is also possible to use cooling water, refrigerant gas, or the like in addition to cooling oil. In particular, when a refrigerant is supplied to cool the pipe line as an evaporator, heat can be efficiently cut off by controlling the flow rate using a thermosensor instead of constantly supplying the refrigerant.

Note that, unless the set temperature is set to a particularly high temperature, the heat exchange in the heat cutoff section is cooling in which a fluid at a constant temperature passing through the pipe absorbs heat from the surroundings.

In addition, the heat shielding parts of the embodiments all isolate heat from a box-shaped or cylindrical hollow structure, but if the structure is a hollow structure, pipes are arranged over the entire surface to be heat-shielded. This constitutes a heat cutoff section.

Furthermore, various processing machines other than the machine tools explained as examples, which have a structure to support processing tools and workpieces, or between processing tools, can also be configured in the same manner to improve processing accuracy. can be increased.

(Effects of the Invention) As described above, according to the first and second inventions, in a continuous structure that supports a processing tool of a processing machine and a workpiece or processing tool, a surface on which a conduit is formed is provided. The structures before and after are thermally insulated, and no heat is exchanged between them.

As a result, if conduits are formed on the surfaces of the structures that make up the processing machine at appropriate positions, the heat generated from each part will not be transmitted to other structures, and the temperature of only that part will rise and thermal expansion will occur. do. In this way, thermal displacement occurs only in a limited part of the structure, while other parts are kept at a constant temperature.
Positional deviations occurring between the processing tool and the workpiece or processing tool are reduced, and processing accuracy is improved accordingly.

[Brief explanation of the drawing]

Fig. 1 is an external view showing the first embodiment of the first invention, Fig. 2 is a cross-sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a cross-sectional view taken along the line ■-■ in Fig. 2. Figure 4 shows the second invention in the first invention.
Fig. 5 is an external view showing the third embodiment of the first invention, Fig. 6 is an external view showing the embodiment of the second invention, and Fig. 7 is a heat shielding part. FIG. 8 is a sectional view showing another embodiment of the present invention, and is an explanatory diagram conceptually showing a mechanism for determining accuracy in a conventional processing machine. 1... Base 2... Table 3... Workpiece 4... Column 5... Head 6... Spindle head 7... Spindle 8... Processing tool 9.
...Heat cutoff section 10...Pipeline 13-15...Heat cutoff section 21...Bend 22...Spindle stock 23...
Workpiece 24... Spindle head 25... Spindle 27... Shinshindai 28... Tailstock shaft 29
...Reciprocating stand 30...Turret post 31...Bite
32 to 38... Heat cutoff section 41... Base 42...
・Table 43... Workpiece 44. 45... Column 46... Head 47... Spindle head 48... Spindle 49... Processing tool 51-5
8... Heat cutoff section 62... Heat exchange vibe 71...
・Base 72...Gui fixing base 73...Die 7
4.75...Column 76...Head 77...
Ram 78...Punch 79...Workpiece 81~
88... Heat cutoff part Figure 4 Figure 7 Figure 5 Figure 6 (-1111 □-1) Do-11111

Claims (2)

[Claims] (1) In a processing machine in which the processing tool processes the workpiece while maintaining the processing tool and the workpiece at specified relative positions, the relative positions of which are supported by a continuous structure such that the relative positions can be changed,
A processing machine characterized in that a conduit through which a fluid at a predetermined temperature is supplied is formed in a structure within a plane intersecting the longitudinal direction of the structure. (2) In a processing machine that moves a processing tool supported by a continuous structure to a specified relative position and processes a workpiece placed between the processing tools, A processing machine characterized in that a conduit through which a fluid at a high temperature is supplied is formed in a structure in a plane intersecting the longitudinal direction of the structure.