JPH0811348B2 - Processing machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a processing machine such as a machining center, a lathe, or a press molding machine.

(Prior art) With machining machines such as machining centers, when trying to improve machining accuracy and perform ultra-precision machining, the obstacles are the workpiece being machined, heat generated from the machine tool, and machining. This is heat generated from a drive source such as a motor provided in the machine. These heats raise the temperature of the work piece and the work tool to cause thermal expansion, and further, the heat is transmitted to the structure of the processing machine itself that supports the work piece and the work tool, and the heat expansion is similarly performed. Give rise to. When these thermal displacements occur, if the entire processing machine expands at a uniform rate at the same time, the relative position between the work piece and the processing tool will not change and will be kept in a normal state. do not become. However, in reality, the displacements caused by the thermal expansion of the respective parts are different, so that the relative position between the workpiece and the processing tool is misaligned.

The model shown in FIG. 8 conceptually shows the mechanism that impedes the improvement of the precision of the processing machine, including the thermal expansion.

The figure shows a case where a tool (working tool) processes a work piece (workpiece) in a machining center. In order to keep the tool and the work piece in a predetermined relative position, a tool holder, a spindle, a gear group, a head, a head feed device, a column, a base, a saddle feed device, a saddle, which are sequentially arranged from the tool to the work piece,
A continuous structure is constituted by the table feeding device, the table, and the fixture. The whole of these continuous structures is C
It can be regarded as a C-shaped frame, and the tool and the work piece are cantilevered at both ends of the C-shaped frame.

In this model shown in the figure, the heat generated from the motor on the upper part of the head and the gear group that transmits the rotation of the motor to the main shaft, and the heat generated during processing between the tool and the workpiece are transmitted to the next structural portion in order. When the temperature rises, the heat generating portion and each structural portion to which the heat is transmitted cause thermal expansion to deform the shape of the C-shaped frame. 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 transfer from other parts, and the expansion rate of each part is different, so that the shape of the entire C-shaped frame is It will be distorted.

Further, when the machining is started, mutually opposing machining reaction forces are generated between the tool and the work piece, and are transmitted to the whole from both ends of the C-shaped frame. As a result, each part of the C-shaped frame is elastically deformed by receiving an external force such as a bending moment according to the magnitude of the processing reaction force. Also in this case, even if each part of the C-shaped frame receives a uniform bending moment, the respective parts have different stiffnesses, so that the amounts of deformation generated in the respective parts are different, and the shape of the entire C-shaped frame after deformation is complicated. It will be

As a result of the combination of thermal expansion and elastic deformation having different displacement rates for each local portion, the relative position between the tool at the tip of the C-shaped frame and the work piece is displaced. With respect to the deviation of these relative positions, a cooling device is installed in the heat generating part of each part,
The rigidity is increased by increasing the rigidity of each structure. However, when trying to further improve the processing accuracy, these generated displacements become a major obstacle.

Therefore, in order to solve these problems fundamentally, the temperature of each part of the C-shaped frame, the processing reaction force and the amount of deformation are detected using various sensors to indirectly estimate the amount of relative positional deviation between the tool and the workpiece. However, a device for compensating the relative positional deviation by NC based on the obtained value or forcibly compensating for the deformation by providing an actuator on the C-shaped frame has been proposed by the inventor of the present application in Japanese Patent Application No. 2-198479. Attitude control device for machine tools ",
And it was proposed as a "processing machine" filed on September 26, 1990.

By using these proposed solutions, it is possible to obtain almost the desired processing dimensional accuracy. Especially for the compensation of the machining reaction force, the value of the machining reaction force and the amount of deformation generated at the start of machining by the tool and the work piece are detected, and the NC software is used to instantly correct the feed amount in the x, y, and z axes. Control with good responsiveness is possible.

Similarly, the temperature sensor also detects the temperature change of each part of the C-shaped frame due to heat generation, and the deformation sensor also detects the deformation due to the temperature rise. It is possible to operate and return both end positions of the C-shaped frame to the normal position.

The model shown in FIG. 8 is, for example, a press molding machine, in which the processing tool is arranged at both ends of the C-shaped frame or the gate-shaped frame and the relative position of the processing tool is moved to a predetermined interval. The same applies to a processing machine that processes a workpiece placed between the. In that case, the C-shaped frame ends shown in the figures are all processing tools, and a mechanism for moving the processing tools to a predetermined position is required.

(Problems 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 deformation amount for each component. In particular, the deformation of the C-shaped frame due to temperature changes is simple because the amount of heat generated by each heat source changes irregularly depending on the processing conditions, and the transmission of that heat to each component is very complicated. It is difficult to accurately grasp the amount of thermal deformation just by assuming such a model. Therefore, it is necessary to actually measure the deformation of each part accurately, and a large number of deformation sensors must be installed in each part.

However, in an actual machine tool or 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 deformation sensors. Therefore, for the portion where there is no room to install the deformation sensor, a temperature sensor that is smaller than the deformation sensor is installed and the deformation amount is estimated from the entire temperature distribution. In this way, the deformation sensor is used for the part where the deformation amount can be directly detected, and the temperature distribution is detected for the part which cannot be directly detected, and the values are combined to grasp and correct the shape change of the entire C-shaped frame. I tried to process it. Therefore, when trying to obtain the deformation amount for each component from the detected temperature distribution, various conditions must be set in advance and the correspondence between the temperature distribution and the generated deformation amount must be measured and stored as data. I won't.

By collecting these data as accurately as possible, it is possible to precisely operate the actuator for the first time and accurately correct the tool and the work piece at the tip of the C-shaped frame.

Although the method proposed in this way can be corrected with high accuracy, there is a problem in that the collection of data required for it is troublesome.

Therefore, if it is attempted to simplify the control for correcting the thermal deformation generated in each part of the entire C-shaped frame, the upper limit of the amount of thermal deformation generated in the C-shaped frame should be set as low as possible to control the thermal deformation range. Should be smaller and the amount of collected data should be smaller.

As described above, even if the deformation sensor or the temperature sensor is installed, if the temperature change of each part is large, the correction amount is large, and as a result, it is difficult to secure the desired accuracy. The same applies to a processing machine that supports a processing tool and a processing tool, such as a press molding machine, and processes a workpiece placed between the processing tools.

The present invention has been made by paying attention to these points, and an object thereof is to determine a relative positional deviation between a processing tool and a workpiece in a processing machine or between the processing tool and the processing tool. In order to reduce the number, it is an object of the present invention to provide a processing machine in which the thermal displacement generated in the structure supporting between the processing tool and the workpiece or the workpiece is reduced.

(Means for Solving the Problems) In order to achieve the above object, a first invention is a relative position in which a work tool and a work object whose relative positions are changeably supported by a continuous structure are designated. In a processing machine in which a processing tool processes a work piece while keeping the above, the structure is divided into a plurality of segments by a surface intersecting the supporting direction,
It is characterized in that a pipe line to which a fluid of a predetermined temperature is supplied is formed in the structure within the boundary surface of each segment.

A second invention is a processing machine for moving a processing tool supported by a continuous structure and a processing tool to a designated relative position to process a workpiece placed between the processing tool and the processing tool. In the above, the structure is divided into a plurality of segments by a surface that intersects the supporting direction, and a pipeline to which a fluid of a predetermined temperature is supplied is formed in the structure in the boundary surface of each segment. And

(Operation) In the first and second inventions, the structure is divided into a plurality of segments by a surface intersecting the supporting direction of the structure, and a fluid of a predetermined temperature is supplied to the structure in the boundary surface of each segment. Due to the formation of the pipe, the segment before and after the pipe has almost the same temperature as the supply fluid. If the temperature rises due to heat generation or heat transfer in one or both of the segments before and after the pipeline, the part of the segment near the pipeline will be absorbed and cooled by the supply fluid and will have a temperature close to the supply fluid. , When one segment is cooled by a cooling liquid etc. and the temperature drops, the segment is heated by the supply fluid and becomes a temperature close to the supply fluid, and heat is transferred to the segment on the opposite side of the pipeline. Absent. In this way, between the segments before and after the boundary surface in which the duct is formed, they are thermally insulated from each other and heat is not transferred.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is an external view showing a first embodiment in which the first invention is applied to a machining center.

In the figure, a table 2 which is movable on a horizontal plane is arranged on the upper right side of a base 1, and a workpiece 3 is fixed on the table 2. On the other hand, a column 4 is installed on the upper left side of the base 1, and a head 5 is mounted on the upper right side of the column 4 so as to be vertically movable. A spindle head 6 is provided below the tip of the head 5 to pivotally support a spindle 7. A processing tool 8 is attached to the spindle 7 to cut the workpiece 3 fixed to the table 2 below. That is, in this machining center, the processing tool 8 for processing and the workpiece 3 to be processed are C
Supported by the shape.

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

As shown in FIGS. 2 and 3, the column 4 has a hollow box-shaped structure, and the heat shield 9 is formed at the lower end of the column 4. The heat shield 9 has a thick wall inside the column 4,
A pipe line 10 for circulating cooling oil is formed. Cooling oil having a predetermined temperature is injected from the inlet 11 of the pipe 10, goes around the inside of the column 4, and is then discharged from the outlet 12. The circulating cooling oil is kept at a predetermined temperature by an oil cooler or the like (not shown). The predetermined temperature of the cooling oil referred to here is the same temperature as the atmosphere in which the machining center is installed.

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

Further, the head 5 also has a hollow box-shaped structure, and a heat shield 14 is formed near the left end connected to and supported by the column 4. In addition, a heat shield 15 is also formed at the root of the spindle head 6 protruding below the tip of the head 5.

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

Here, a part of the processing heat generated when the processing tool 8 processes the workpiece 3 is transmitted to the spindle 7 and the spindle head 6 in order as the temperature of the processing tool 8 is raised, and the temperature of the spindle 7 and the spindle 6 is increased. Raise. As the temperature rises, each part expands and its size increases. But,
Since the heat shield 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, in the head 5, there is a motor (not shown) for driving the spindle 7 and a gear group for transmitting the rotation thereof, so that heat is generated while the spindle 7 is driven. This heat generation raises the temperature of the head 5, but the heat is not transmitted to the spindle head 6 side because of the heat blocking portion 15. Similarly, heat is not transmitted to the column 4 side because of the heat blocking portion 14. Further, the column 4 also has the heat blocking portion 9 at the boundary with the base 1 and the heat blocking portion 13 at the upper portion, so that there is no heat transfer between the columns 4 or the base 1 even if the temperature varies. .

In the machining center of the embodiment, a plurality of heat blocking portions are installed in the plane orthogonal to the supporting direction of the C-shaped frame that supports the processing tool 8 and the work piece 3 in this way, so that the heat generated by each portion is different. Is prevented from being transmitted to the portion, and the occurrence of thermal deformation due to heat generation is limited to a specific section. As a result, the deformation of the entire C-shaped frame structure is suppressed to a small extent, the amount of relative displacement between the workpiece 3 and the processing tool 8 is reduced, and the processing accuracy is improved.

That is, as shown in the embodiment, the processing tool 8 and the workpiece 3
When the C-shaped frame that supports and is divided into a plurality of parts by the heat shields orthogonal to the supporting direction, each structure part is thermally insulated from other structure parts, and even if heat is generated in a specific part, the generated heat The temperature rise and thermal expansion due to H.sub.2 remain within that section and the other sections are completely unaffected. As a result, the places where the C-shaped frame is deformed due to heat generation are limited, and the amount of deformation that occurs in the entire C-shaped frame becomes a small value.

Further, when it is attempted to accurately grasp the shape change of the entire C-shaped frame by also referring to the temperature distribution like the above-described processing machine already proposed by the inventor of the present application, the target processing machine is With such a configuration, the location where thermal deformation occurs is limited to a specific component, and it is possible to easily construct a model for control.

Of course, even for a conventional processing machine that does not have a control device that corrects a minute deformation of the structure portion, by configuring the structure portion as in the embodiment, the relative displacement between the workpiece and the processing tool is The amount is reduced and the processing accuracy is improved.

The installation position and number of the heat shields are required depending on the physical structure of the applicable processing machine, the amount of heat generated by each heat source, the heat transfer characteristics of each unit, and the heat absorption capacity of the heat shields installed. It is determined in consideration of processing 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 on the upper left side of the bed 21, and a spindle head 24 protruding on the upper right side pivotally supports a spindle 25. The spindle 25 holds the workpiece 23 by tightening the chuck 26. Workpiece
When 23 is long, the other end of the work piece 23 is supported by a tailstock shaft 28 supported by a tailstock 27.

A carriage 29 is supported on the upper center of the bed 21 so as to be movable left and right, and a tool rest 30 installed on the upper and lower parts thereof is moved back and forth, whereby a bite 31 attached to the tool rest 30.
Cuts the rotating workpiece 23.

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

Further, the bed 21, the headstock 22, the spindle head 24, the tailstock 27, and the carriage 29, which are the respective constituent parts, have a hollow box shape or a cylindrical shape, and are provided at their respective end portions or intermediate portions. The heat shields 32 to 38 are formed perpendicular to the support direction.

The heat shields 32 to 38 have substantially the same structure as the heat shields 9 and the like installed in the machining center shown in FIG. 1, and circulate the cooling oil of the same temperature in each of them to generate heat before and after that. Prevent it from being transmitted. In this way, as in the case of the above-mentioned machining center, the heat generated during processing is provided with the heat blocking portions 36 to 38, so that the bed 21 and the headstock can be
Transmission to the 22 side is prevented.

Further, the motor for driving the spindle 25 is inside the bed 21 on the left side of the heat cutoff portion 33 (not shown), and the gearbox for changing the rotation is not shown, but the heat cutoff portion 33 and the heat cutoff portion 33 corresponding to the upper portion of the motor are also cut off. Headstock 22 between parts 34
It is stored inside. Since these heat generations are surrounded by the heat cutoff portion 33 and the heat cutoff portion 34, or the heat cutoff portion 34 and the heat cutoff portion 35, respectively, they are prevented from being transmitted to other portions.

In the lathe of the embodiment, a plurality of heat blocking portions are installed in the plane orthogonal to the supporting direction of each portion of the C-shaped frame that supports the work piece 23 and the cutting tool 31 in this way, and the heat generation of each portion is different. Since it is prevented from being transmitted to a portion, the occurrence of thermal deformation due to heat generation is limited to a specific section, so that the deformation due to heat generation of the entire C-shaped frame structure can be suppressed. As a result, the amount of relative displacement between the work piece 23 and the cutting tool 31 is reduced, and the 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 gate-shaped machining center is a combination of the C-shaped frame structure of the machining center shown in FIG.

In the figure, a table 42, which is movable on a horizontal plane, is arranged at the upper center of a base 41, and a workpiece 43 is a table.
Fixed on 42. On the other hand, columns 44 and 45 are installed on both upper sides of the base 41, and a head 46 is attached to the inside of the upper parts of the columns 44 and 45. A spindle head 47 is provided below the head 46 and supports a spindle 48. A work tool 49 is attached to the spindle 48, and the lower table 42 is attached.
The workpiece 43 fixed to is cut.

Heat shields 51 and 52 are formed inside the installation positions of the columns 44 and 45 on both sides of the base 41.

Further, in the columns 44 and 45, heat blocking portions 53 and 54 are formed at the boundary with the base 41 at the lower end, and heat blocking portions 55 and 56 are further formed in front of the installation position of the head 46 at the upper portion. .

Furthermore, heat blocking portions 57 and 58 are also formed at the boundaries between the columns 44 and 45 and the head 46.

Each of the heat shields 51 to 58 has substantially the same structure as the heat shield 9 and the like described above.

Also in the case of this embodiment, the heat generated in each structural portion is prevented from being transmitted to other portions, so that the deterioration of the processing accuracy due to the occurrence of thermal deformation can be suppressed to the minimum.

FIG. 6 is an external view showing an embodiment in which the second invention is applied to a press molding machine.

The entire structure of this press molding machine, except for the processing part, is constructed similarly to the portal-type machining center shown in FIG.

In the figure, a die fixing base 72 is arranged on the upper center of a base 71, and a die 73 as a processing tool is fixed on the upper surface thereof. On the other hand, columns 74 and 75 are installed on both upper sides of the base 71, and a head 76 is attached to the inside of the upper parts of the columns 74 and 75. A ram 77 that moves up and down is supported below the head 76. A punch 78, which is a processing tool, is attached to the ram 77 to plastically process a workpiece 79 set between the ram 77 and the die 73 below.

Heat shields 81 and 82 are formed inside the installation positions of the columns 74 and 75 on both sides of the base 71.

Further, in the columns 74 and 75, heat blocking portions 83 and 84 are formed at the boundary with the base 71 at the lower end, and heat blocking portions 85 and 86 are further formed in front of the installation position of the head 76 at the upper portion. .

Further, heat blocking portions 87 and 88 are also formed at the boundary portions between the columns 74 and 75 and the head 76.

Each of the heat shields 81 to 88 has substantially the same structure as the heat shield 9 and the like described above.

Also in the case of this embodiment, since the heat generated in each structural part is prevented from being transmitted to other parts, the distance between the two when the die 73, which is a processing tool, descends and comes closest to the punch 78, which is also the processing tool. Variation can be suppressed to a minimum, and the processing size can be maintained with high accuracy.

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

The heat cutoff portion is formed by winding a ring-shaped heat exchange pipe 62 around the outer periphery of a component portion 61 such as a box-shaped column. In order to improve the amount of heat transferred between the heat exchange pipe 62 and the constituent portion 61, the shape of the inner portion of the heat exchange pipe 62 that contacts the outer surface of the constituent portion 61 is made flat to increase the contact area.

When the heat shield is configured in this way, the heat shield can be installed at any position and can be relocated.

In this figure, the heat exchange pipe 62 is wound on the outside, but it can be installed inside the component part 61, and if it is installed from both sides, the heat blocking effect is increased.

In the embodiment of the heat shield 9 shown in FIGS. 2 and 3, the number of passes of the pipeline 10 is one, but if possible in terms of processing and strength, a plurality of pipelines 10 should be formed. As a result, the contact area of the cooling oil can be increased, and the efficiency of heat exchange can be increased. Similarly,
The cross-sectional shape of the pipe line 10 may be other than circular, or a groove or the like may be formed to increase the contact area and increase the amount of heat exchanged.

Furthermore, as the fluid that passes through the pipeline 10, cooling water, a refrigerant gas, or the like can be used in addition to the cooling oil. In particular, when the refrigerant is supplied to cool the pipeline as an evaporator, the refrigerant is not always supplied and the thermosensor is used to control the flow rate to efficiently cut off heat.

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

In addition, the heat-shielding portions of the examples all heat-shield a box-shaped or cylindrical hollow structure portion, but when the structure portion is solid, the pipes are arranged on the entire heat-shielding surface. To form a heat shield.

Furthermore, regarding various processing machines other than the machine tool described as the embodiment and having a structure for supporting between the processing tool and the processing tool, or between the processing tool and the processing tool, the structural parts thereof are configured in the same manner and the processing accuracy is improved. Can be increased.

(Effect of the Invention) As described above, according to the first and second inventions, a continuous structure that supports the processing tool of the processing machine and the workpiece or the processing tool is formed by the surface intersecting the supporting direction. By dividing into a plurality of segments, in the structure within the boundary surface of each segment, by forming a pipeline to which the fluid of a predetermined temperature is supplied, between the segments before and after the boundary surface where the pipeline is formed, They are thermally insulated from each other and heat is not transferred.

As a result, when heat is generated and cooled in a specific portion of the structure, the heat generated and cooled is transmitted only within that segment, and the thermal expansion and contraction of that segment only. In this way, thermal deformation occurs only in the heat generation / cooling part of the structure and does not affect other parts, so there is little positional deviation between the processing tool and the workpiece or processing tool. Therefore, the processing accuracy is improved accordingly.

[Brief description of drawings]

1 is an external view showing a first embodiment of the first invention, FIG. 2 is a sectional view taken along the line II-II in FIG. 1, and FIG.
FIG. 4 is a cross-sectional view taken along line III-III, FIG. 4 is an external view showing a second embodiment of the first invention, FIG. 5 is an external view showing a third embodiment of the first invention, and FIG. FIG. 7 is an external view showing an embodiment of the second invention, FIG. 7 is a sectional view showing another embodiment of the heat-shielding portion, and FIG. 8 is a conceptual illustration of a mechanism for determining accuracy in a conventional processing machine. It is a figure. 1 ... Base, 2 ... Table, 3 ... Workpiece, 4 ...
… Column, 5 …… Head, 6 …… Spindle head, 7
...... Spindle, 8 …… Processing tool, 9 …… Heat insulation part, 10 ・ ・ ・
… Pipe line, 13 to 15 …… Heat insulation part, 21 …… Bed, 22 …… Headstock, 23 …… Workpiece, 24 …… Spindle head, 25…
… Spindle, 27 …… tailstock, 28 …… tailstock shaft, 29 …… reciprocating carriage, 30 …… tool rest, 31 …… bite, 32 to 38 …… heat shield, 41 …… base, 42… … Table, 43 …… Workpiece,
44,45 …… Column, 46 …… Head, 47 …… Spindle head, 48 …… Spindle, 49 …… Processing tool, 51 to 58 …… Heat cutoff part, 62 …… Heat exchange pipe, 71 …… Base, 72-die fixing base, 73-die, 74,75-column, 76-head, 77-ram, 78-punch, 79-workpiece, 81-
88 ... Heat shield

Claims (2)

[Claims] 1. A processing machine for processing a work piece while the work tool and a work piece, the relative position of which is changeably supported by a continuous structure, are held at a specified relative position. A processing machine characterized by dividing an object into a plurality of segments by a surface intersecting the supporting direction, and forming a pipeline to which a fluid of a predetermined temperature is supplied in the structure within the boundary surface of each segment. . 2. A processing machine for moving a processing tool supported by a continuous structure and a processing tool to a designated relative position to process a workpiece placed between the processing tool and the processing tool. The structure is divided into a plurality of segments by a surface that intersects the supporting direction, and a pipeline for supplying a fluid of a predetermined temperature is formed in the structure within the boundary surface of each segment. Processing machine.