JP2000127035A - Thremal deformation counter measure bed and grinding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make occurrence of thermal deformation difficult by disposing a water storing chamber at the inside of a bed and filling water within the water storing chamber. SOLUTION: In water storing chambers 22, 22a, water with large specific heat is filled from a filling port 24. As a result, thermal capacity of the whole of a bed 2 is increased. Because grinding fluid of a high temperature is scattered on also a part except a grinding fluid channel, local heating for the bed 2 is irregularly performed. Because thermal capacity of the bed 2 itself even in this case, a change in temperature is small and thereby thermal deformation of the bed 2 becomes small. Therefore, because a positional relation among a table sliding along a guide part, a headstock 6 and a tailstock arranged on the table and a wheel spindle stock 5 installed on the bed 2 is not affected by heat and a fixed relation is maintained from the time of starting working to the time of terminating working, fixed high working accuracy can be obtained from the beginning of working to the last.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bed against heat deformation applied to a grinding machine and a grinding machine provided with the bed against heat deformation. In addition, the thermal deformation countermeasure bed of the present invention,
It can be applied to other machine tools such as lathes.

[0002]

2. Description of the Related Art Grinding machines that use a grindstone as a processing tool are characterized by high processing accuracy and a high-quality finished surface, and are indispensable for mass-produced precision machining. It is impossible to exist.

[0003] In the above-mentioned grinding machine, a grinding fluid (coolant fluid) is usually used for grinding. The grinding fluid is applied around the grinding wheel and the workpiece to be ground for the following purpose. 1) Lubrication to reduce friction between abrasive grains, binder and chips, and finished surface 2) Direct cooling to reduce grinding temperature and workpiece temperature 3) Elimination of chips, rust prevention and protection of finished surface

[0004] Since the temperature of the grinding fluid used for such a purpose rises with the passage of time due to its direct cooling action, the high-temperature grinding fluid may fall on the bed and cause thermal deformation in the bed. is there. When such thermal deformation occurs, the positional relationship between the workpiece and the grindstone is different from that at the start of processing, or the positional relationship in the grinding direction changes, thereby adversely affecting the grinding accuracy of the workpiece. Will be. For this reason, in the conventional grinder, it has responded by designing the bed shape to be a so-called thermal symmetry.

[0005]

However, even if the bed has the above-mentioned conventional thermal symmetry, the point to which heat is applied, that is, the position where the high-temperature grinding fluid falls, is not necessarily symmetric, so that the thermal deformation is caused. It was extremely difficult to completely prevent By the way, one common bed
It is said that if the temperature rises by 100 ° C., the bed will extend about 1 μm per 100 mm. For example, if a temperature rise of 20 ° C. occurs in the bed, the bed will be deformed by about 20 μm. Such thermal deformation is so large that it exceeds the range of normal dimensional tolerance in grinding.For example, when grinding the outer peripheral surface of a cylinder, unnecessary taper is formed in the axial direction of the workpiece. Become. Therefore, in order to further increase the processing accuracy of the grinding processing, effective measures against thermal deformation of the bed are required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a bed for preventing thermal deformation and a grinding machine provided with the bed for preventing thermal deformation.

[0007]

In order to solve the above-mentioned problems, the present invention employs the following means. The bed for preventing thermal deformation according to claim 1, which is a bed for a machine tool that supports a movable portion, wherein a water storage chamber is provided inside the bed, and the water storage chamber is filled with water. It is.

[0008] According to such a bed against heat deformation, the heat capacity of the entire bed increases, so that heat deformation hardly occurs. In addition, if the water storage chamber is arranged below the grinding fluid flow path through which the high-temperature grinding fluid dropped from the processing part flows, thermal deformation can be made hard to occur with a relatively small amount of water.

[0009] The bed for preventing thermal deformation according to claim 2 is characterized in that the water is a grinding liquid or strong alkaline water.

According to such a bed against heat deformation, it is possible to prevent rust and rot in the water storage chamber. In this case, the strong alkaline water preferably has a pH of 8.5 to 10.

A grinding machine according to a third aspect of the present invention includes a bed for preventing thermal deformation, in which a water storage chamber filled with water is disposed inside the bed.
A table slidably supported on the thermal deformation countermeasure bed, a headstock provided with a drive source for rotating the workpiece, a tailstock for supporting the workpiece together with the headstock, and the workpiece And a grindstone table provided with a drive source for rotating and driving the grindstone.

According to such a grinding machine, since the heat capacity of the entire bed is increased and it is difficult to thermally deform, the processing accuracy can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bed and a grinder according to the present invention will be described below with reference to the drawings. FIGS. 5A and 5B schematically show a cylindrical grinder as an example of a grinder. FIG. 5A is a perspective view and FIG. 5B is a front view.
This cylindrical grinding machine performs grinding and finishing on the outer periphery of a cylindrical workpiece by a rotating grinding motion of a grinding wheel 1 and a rotating feed motion of a workpiece (work) W.
Is a table, 4 is a tailstock, 5 is a grindstone, 6 is a headstock, 7
Denotes an operation panel, 8 denotes a control panel, 9 denotes a coolant device, 10 denotes a hydraulic / lubricating oil device, and 11 denotes a longitudinal positioning device.

On the bed 2 of the grinding machine, there is provided a table 3 which slides on the bed 2. The table 3 is moved in the left-right direction on the paper by driving a table feed motor (not shown). A headstock 6 and a tailstock 4 are disposed on the table 3, and the headstock 6 has a spindle 6a, and the tailstock 4 is a tailstock 4a.
have. The workpiece W is supported by the main shaft 6a and the tailstock shaft 4a, and is rotated around the main shaft 6a provided with a drive source as a drive shaft. The rotation of the spindle 6a is performed using a spindle motor (not shown) provided on the headstock 6 as a drive source.

On the other hand, a grindstone 1 for grinding a workpiece W is supported on a grindstone table 5 and is rotated by a grindstone drive motor (not shown). Further, the wheel head 5 installed on the bed 2 is provided with a wheel head feed motor (not shown).
Thus, the movement is controlled in the vertical direction of the paper surface (the direction orthogonal to the movement direction of the table 3 on the horizontal plane).

The above-described table feed motor and wheel head feed motor are both constituted by servomotors, and based on various control data input to the operation panel 7,
The control panel 8 is configured to numerically control these. The feed movement of the workpiece W in the axial direction is performed by the grindstone table 5.
And to the headstock 6.

The coolant device 9 supplies a grinding fluid (coolant) to a nozzle 9a provided in the vicinity of the grinding portion. It is radiated toward. As a result, the grinding fluid removes heat generated by the grinding process and cools it, and at the same time, removes chips and abrasive grains from the processed portion by flowing. The grinding fluid radiated from the nozzle 9a falls on a grinding fluid channel of the bed 2 described later and is collected, and is circulated and reused in the same manner.

In the hydraulic / lubricating oil device 10, the hydraulic device operates a fixed-size gauge (not shown), and the lubricating oil device is
And forcibly lubricating the sliding portion of the table 3. The longitudinal positioning device 11, which is usually called a locator or a probe, is a device for measuring the degree of variation in the longitudinal direction of the workpiece.

Next, the structure of the bed 2, which is a component of the above-described grinding machine, will be described in detail with reference to FIGS. The bed 2 has a table 3, a tailstock 4, and a grindstone 5
And a cast part that supports a movable part such as the headstock 6,
For the weight and grinding force of each part, not only strength but also sufficient rigidity is required statically and dynamically. For this reason, a partition 21 is provided in a lattice shape inside the bed 2, and the water storage chambers 22 divided by the partition 21 are arranged side by side in the front, rear, left and right over the entire area in plan view. Also, a grinding fluid flow path 2 to be described later
A water storage chamber 22a is also formed below 6. These water storage chambers 22 and 22 a are provided with communication holes 2 provided in each partition 21.
The water storage chambers 22 and 22a are connected to filling ports 24 provided at four locations.

The above-mentioned water storage chambers 22 and 22a are filled with water having a large specific heat from a filling port 24. In this case, in particular, in consideration of prevention of decay of the water itself in addition to rust prevention of the bed 2, strong alkaline water having a pH of 8.5 to 10 is filled. As a result, the heat capacity of the entire bed 2 increases,
Even if it receives heat from the outside, the temperature hardly rises. Further, a corrosion layer is formed on the surfaces of the water storage chambers 22 and 22a by reacting with the strong alkaline water. Since this corroded layer becomes a protective film having the same action as aluminum oxide or the like, it is possible to prevent corrosion from reaching the inside of cast iron which is a constituent member of the bed 2. The water to be filled in the water storage chambers 22 and 22a may be, for example, a coolant liquid used for grinding, in addition to the strong alkaline water.

On the upper surface of the bed 2 described above, a pair of guide portions 25, such as a V sliding surface or a linear roller guide for slidably supporting the table 3, are provided in parallel. The nozzle 9a is provided on the upper surface of the bed 2.
A grinding fluid flow path 26 is formed to collect the grinding fluid radiated from the fluid toward the processing part and dropped. This grinding fluid channel 2
6 is provided on the outer peripheral portion of the upper surface of the bed 2. In the illustrated example, the portion hatched in FIGS. 2 and 3 is the grinding fluid flow path 26, and the grinding fluid collected in the grinding fluid flow path 26 flows in the direction indicated by the arrow 27 in FIG. 9
To the grinding fluid tank.

The temperature of the grinding fluid that has fallen into the grinding fluid channel 26 in this way increases with the processing heat as time passes, and the bed 2 is heated. As described above, the heating by the grinding fluid flowing through the grinding fluid channel 26 as intended can be dealt with to some extent even with a thermosymmetric bed shape, Also, since the high-temperature grinding fluid is scattered, local heating of the bed 2 is irregularly performed. Even if this happens,
Since the heat capacity of the bed 2 itself is large, the temperature change is small, and therefore, the thermal deformation of the bed 2 is small. Therefore, the table 3 that slides along the guide portions 25, 25
A headstock 6 and a tailstock 4 installed on the table 3
And the positional relationship between the grinding wheel table 5 and the grinding wheel table 5 installed on the bed 2 is not affected by heat, and a constant relationship is maintained from the start of processing to the end of processing. High processing accuracy can be obtained.

In the above embodiment, the water storage chamber 2
2 and 22a are provided over the entire area of the bed 2, but in other embodiments, the water is stored only in the water storage chamber 22a (see the cross-hatched portion in FIGS. 1 and 4) located below and around the grinding fluid flow path 26. May be filled. In this way, although the overall heat capacity does not increase so much, the heat capacity can be increased with a relatively small amount of water in the region most susceptible to the thermal influence of the high-temperature grinding fluid.

[0024]

According to the thermal deformation countermeasure bed of the present invention described above, the heat capacity of the entire bed is increased and the temperature is hardly changed, so that the bed is hardly deformed even when it receives external heat. For this reason, it is possible to prevent the positional relationship between the movable parts supported on the bed from changing, and therefore, the grinding machine employing this bed maintains high processing accuracy without being affected by the temperature. it can. In addition, when only the water storage chamber in the lower peripheral portion of the grinding flow path is filled with water, the heat capacity of a region most susceptible to heat can be increased with a small amount of water. Filling the water storage chamber with strong alkaline water can prevent the bed from being corroded by the filling water and prevent the filling water itself from decay, so that the durability of the bed and the grinder using this bed is improved. It has the effect of improving and facilitating maintenance.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG. 2, showing an embodiment of a bed against heat deformation according to the present invention.

FIG. 2 is a plan view showing the thermal deformation countermeasure bed of FIG.

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a partial cross-sectional view taken along line BB of FIG. 2;

5A and 5B are diagrams showing a schematic configuration of a cylindrical grinding machine, wherein FIG. 5A is a perspective view and FIG. 5B is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Whetstone 2 Bed 3 Table 4 Tailstock 5 Whetstone stand 6 Headstock 7 Operation panel 8 Control panel 9 Coolant device 21 Partition wall 22, 22a Water storage chamber 23 Communication hole 24 Filling port 26 Grinding fluid channel W Workpiece

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junji Hoshide 130 Rokujizo, Ritto-cho, Kurita-gun, Shiga Prefecture Mitsubishi Heavy Industries, Ltd. (72) Inventor Makoto Yamagami 130 Rokujizo, Rikuto-cho, Kurita-gun, Shiga Prefecture F-term (reference) 3C034 AA20 BB12 DD20 3C048 BB02 EE02

Claims (3)

[Claims] 1. A bed for a machine tool supporting a movable part, wherein a bed is provided inside the bed, and the bed is filled with water. 2. The bed according to claim 1, wherein the water is a grinding liquid or a strong alkaline water. 3. A bed for preventing thermal deformation in which a water storage chamber filled with water is disposed inside the bed, a table slidably supported on the bed for preventing thermal deformation, and a drive source for rotating a workpiece. A headstock, a tailstock that supports the workpiece together with the headstock, a grindstone that grinds the workpiece, and a grindstone head that includes a drive source that rotationally drives the grindstone. Grinding machine characterized by comprising.