JPH04171176A - Machine tool - Google Patents

Abstract

PURPOSE: To obviate bellows and a cover by completely protecting a movable element from contact with a refrigerant. CONSTITUTION: A refrigerant is recovered between first/second cover means 34, 33 after cooling a contact area of a work means 50 and a workpiece 48. Contact of the refrigerant and first/second slide members 3, 10 is also prevented by the first/second cover means 34, 33.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a machine tool such as a grinder, and more particularly to a machine tool having an improved cooling device. In particular, the present invention relates to a grinding machine having an improved arrangement for cooling heat generating areas due to contact between the workpiece and the grinding wheel.

<Prior art and its problems> In conventional grinding technology, the use of creep feed grinders has become mainstream as it is capable of quickly grinding away large amounts of material using the latest grinding wheels. The advantage of a grinding machine using a grinding wheel, compared to metal grinding tools such as milling cutters and profile milling cutters, is that the grinding wheel can be machined into almost any shape. Modern grinding wheel manufacturing technology allows materials such as ceramics to be processed, which were previously impossible to process.

Conventional creep feed grinders must be sufficiently strong and rigid in order to perform the grinding process with high horsepower to achieve sufficiently deep grinding in one step. Furthermore, such grinders needed to be versatile enough to perform a variety of different grinding processes. When grinding different materials, it is necessary to perform different types of cooling treatments to improve the efficiency of the grinding process. For example, cutting oil is usually used to grind quench-hardened steel, but soluble water (meaning water with a corrosion inhibitor) is used as a coolant to grind carbide, etc. used.

However, when soluble water is used, even though it contains a corrosion inhibitor, it corrodes the highly precisely machined slide member and destroys the precision of the creep feed grinder in a relatively short period of time. There was a disadvantage. Conventional creep feed grinders must be extremely accurate. The various moving parts in the grinding machine are CN
C controlled. For ultimate precision, grinding machines are in some cases equipped with instruments that measure temperature changes, and this measurement data automatically compensates for possible thermal expansion in the part when a predetermined limit value is exceeded. will be held.

A creep feed grinder of the type described above is manufactured, for example, under the trade name "ITM3000" by the applicant, International Tool Machine, Inc. of Westport, Connecticut, USA. This type of creep feed grinder is required to perform highly accurate grinding processing. When performing high-precision grinding, in order to prevent dimensional changes in the main moving parts of the grinder due to temperature changes, a coolant such as water or oil is used to keep the main moving parts at a constant temperature. It is especially important to retain Since this type of grinding machine works at high temperatures in its grinding zone, the main mechanical elements of the grinding machine need to be adjusted during the grinding process, but it is impossible to control them 100%. .

Conventional grinding machines, whether they perform creep feed grinding or normal grinding, are constructed so that all slide members, spindles, etc. are mounted and supported on the main base. . If the grinding machine is operated using only a small amount of coolant, only a small and limited space is required for the area surrounding the grinding wheel. However, the base body must be completely covered by a hood, especially in creep-feed grinding machines, when large amounts of refrigerant are required or when the cooling process is carried out by spraying compressed refrigerant onto the grinding wheel. Creep feed grinders of this type are rigidly constructed and necessarily large, since all the slide members must be distributed over the base body in such a way that their movements do not interfere with each other. Conventional grinders include bellows that cover the slide member and ball screw to protect them from contact with coolant. In some cases, the bellows cover is provided with compressed air to prevent contact between the refrigerant and the slide member to prevent damage to the slide member due to corrosion. These protective measures covering the moving parts of the grinding machine also prevent
100% protection from moisture is not possible.

SUMMARY OF THE INVENTION The present invention therefore aims to provide improved protection means for avoiding contact between a refrigerant and a movable sliding member of a machine tool. Such protection prevents contact between the coolant and the slide member, so that the accuracy of the grinding process by the machine tool is not affected by rapidly increasing thermal energy or by an increase in the temperature of the coolant; No need for active control. At the same time, the number of temperature measuring devices normally used for machine slides can be reduced or even eliminated.

Similarly, bellows for the slide member and ball screw are no longer required.

A machine tool according to the present invention includes a first base body, a first slide member arranged so as to be linearly slidable on the first base body, and a first slide member arranged so as to be linearly slidable on the first base body. a second sliding member, a first bushing means fixed on the second sliding member, and a support column disposed within the first bushing means for predetermined reciprocating vertical sliding movement; a machining means disposed on the support column; a driving means for driving the machining means; a second base body fixed on the first base body; and a drive means rotatably disposed within the second base body. a bearing, a support shaft rotatably disposed within the bearing, a workpiece holding table fixed rotatably about a vertical axis on the support shaft, for abutment with the processing means; a workpiece holding means disposed on the workpiece holding table for holding a workpiece; and a workpiece holding means disposed on the second base and extending through the first bushing means and the support column; second bushing means having an inner diameter greater than an outer diameter of the bushing means arranged to permit lateral movement of the first bushing means; and a second bushing means secured to surround the first bushing means. a first cover means fixed to said second bushing means above said first cover means; vertical wall means joined to the bottom surface of the cover means of No. 2, a refrigerant storage means for storing a refrigerant, and a refrigerant for dispersing the refrigerant from the refrigerant storage means toward a contact area between the work means and the workpiece. and a dispersion means.

Function> After cooling the contact area between the working means and the workpiece, the coolant is collected between the first and second cover means. Refrigerant and 1st
and contact with the second sliding member is prevented by the first and second cover means. - <Example> A creep feed grinder according to the present invention will be described in detail with reference to the attached drawings.A support plate 3, which is a first slide member, is mounted on a first base body 1 of this grinder, and a slide rail 2 is mounted on a support plate 3, which is a first slide member. It is placed so that it can slide through it. The support plate 3 is movable by a servo motor 4 having a coupling 5 and driving a ball screw 6 via a bearing 7. This motor 4 is fixed on a block 8 fixed on the base 1. The support plate 3 also supports a second slide member, a block 10, via a slide rail 9, so that the slide block 10 is movable in the vertical direction with respect to the movement of the support plate 3. The slide block 10 is movable via a drive motor 14, a coupling 13 and a ball screw 11. The drive motor 14 is arranged on a block 15 fixed on the support plate 3.

The drive motors 4 and 14 are each independently controlled by a CNC control unit. Further, the support column or vertical column 18 can reciprocate along the vertical axis Z and can reciprocate along a plane in the vertical axis Z in any angular direction. The slide block 10 has a guide bush 17 that guides the vertical column 18 and accommodates it so that it can slide back and forth. The vertical column 18 has an internal slot 20 for receiving a sliding shoe 21 provided therein by a pin 22. A wedge 23 is slidably disposed on a slide block 24 supported on the bush 17. This wedge 23 is connected to a ball screw 25 held in a bearing 26.
It is driven by a servo motor 28 via a coupling 27 attached to the servo motor 28. The bearing 26 is arranged within a housing 29, which is supported on the slide block 10. The wedge 23 is a rotating ball screw 2
5 to the right in FIG. 3, and also to the left by the ball screw 25,
The column 18 is moved up or down along the vertical axis Z. Motor 28 may be controlled by the CNC control unit that controls motors 4 and 14.

In this way, by appropriately adjusting the drive of the motors 4.14 and 28, the column 18 can be moved up and down or on the horizontal plane in a desired angular direction. The grinding spindle 30 can be moved to a desired position.

The second base body 31 is supported on the first base body 1 (see FIG. 3). This basic body 31 surrounds in its vertical walls 68 most of the movable sliding members 3 and 10 and the members placed thereon, when viewed in plan. The base body 31 has a bushing 32 formed with an opening large enough to accommodate said movement of the column 18, i.e. the horizontal movement carried out by the slide member 3.10 as well as the vertical movement carried out by the wedge 23. There is.

Thus, the machine of this embodiment is designed so that the bushes 17 and 32 do not come into contact with each other.

A stop plate 33 is fixedly provided in the recessed portion of the bush 32. A coolant receiving groove 34 having a discharge vibrator 35 is formed below the stop plate 33 . An O-ring 72 (
FIG. 4) is attached to the stop plate 33 and the vertical wall portion 3.
This ensures a reliable seal between these members even when there is a relative movement of 4 degrees.

The operation of the machine of this embodiment is as follows.

A storage tank 70 for coolant is provided on the base body 31 and supplies coolant via a pair of nozzles (see arrows in FIG. 3) to the area where contact occurs between the grinding wheel 50 and the workpiece 48. .

For example, the coolant is stored in a tank with a capacity of 30 gallons (approximately 114 liters) and has a pressure of 30 psi (approximately 2.1 bytes/hour).
The contact area can be sprayed with a pressure of 1/4 inch.

The coolant collected in the coolant receiving groove 34 is returned to the storage tank 70 from the discharge vibe 35 via the filter/circulation pump 73.

A large amount of coolant leaks into the O-ring 72 and the bottom surface 3 of the stop plate 33.
In order to prevent leakage from between the compressed air source 71 and the
The coolant is fed into the chamber defined by the coolant receiving groove 34 and the stop plate 33 from the pneumatic inlet 37 under a pressure of less than 1/2 cm.

An air suction is thus created within the chamber to prevent fluid leakage from the seal between the O-ring 72 and the stop plate bottom surface 36.

Base body 31 includes a support mechanism for pivoting about axis U49. The pivot 49 is formed by a bearing 40, which is connected to a worm gear drive to permit a desired pivot movement over at least 90°.

The entire worm gear drive mechanism 41 , 40 is mounted within a housing 42 which is mounted within the second base body 31 by means of mounting bolts or screws 43 . Second
Such a mounting on the base body 31 facilitates disassembly or replacement of the entire drive mechanism 41,40. A shaft 39 is provided inside the bearing 40, and a table 44 fixed to the pivot 39 by mounting bolts 45 is supported by the shaft.

This table 44 can be provided with a center 46 and a drive head 47 for holding a workpiece 48. The workpiece 48 is machined by the grinding wheel 50 in this stationary state.

The arrangement described above provides rotation about the axis 49 of the pivot shaft 39, and the workpiece 48 is rotated by the grinding wheel 50.
can take different angular positions with respect to the

The grinding wheel drive mechanism has a mounting plate 51 which is attached to the column 18 by threaded bolts 52. The mounting plate 51 supports a heavy spindle housing 53 fixedly mounted above it by means of threaded bolts 54 .

The spindle housing 53 has a rotatable grinding spindle 30, which is clamped in the housing in a known manner by a clamping screw 55. As shown in FIG. 3, a housing 57 for a grinding wheel motor 59 is fixedly mounted on the spindle housing 53 via a mounting plate 58. A drive pulley 60 mounted on the shaft of the motor 59 is connected via a drive belt 62 to a drive pulley 61 of the grinding spindle 30 . In this way, the drive servo motor 59 causes the grinding spindle 30 to rotate via the drive belt 62. The mounting plate 51 also has a shaft 6
4 is supported. shaft 64
is clamped and fixed on a clamp plate 65, which is attached to the bushing 17 by a clamp screw 66. Such a configuration prevents relative rotation of the spindle housing 53 with respect to the bushing 17, but removes the shaft 64 (thereby allowing rotation of the spindle housing 53 with respect to the bushing 17). is enclosed within a coolant pan 67 and enclosure 68 to prevent coolant from being sprayed outside the grinding wheel contact area. To do this, a coolant recovery groove 69 surrounds the substrate 31.

<Effects of the Invention> According to the machine tool of the present invention, its main movable elements are completely protected from contact with the coolant, so there is no need for bellows or covers commonly used in conventional grinding machines. Since the main sliding member is avoided from contact with the coolant, the high heat generated by such contact will not cause dimensional changes. According to the present invention, a creep feed grinder can be operated with cooling oil or cooling soluble water without sacrificing essential accuracy in the operation of the slide member.

Furthermore, the invention provides a creep-feed grinding machine with a simple and compact construction, which also leads to a reduction in the overall manufacturing costs of the grinding machine.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the configuration of a creep feed grinder according to the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a sectional view showing its main parts, and Fig. 4 is a section of D in Fig. 3. FIG. 5 is an enlarged cross-sectional view showing details, and is a cross-sectional view taken along a cut plane perpendicular to the cut plane of FIG. 3. Explanation of symbols 1...First base 3...Support plate (first slide member) 4...Motor 7...Bearing 10...Slide block (second slide member) 1
4...Motor 17...Guide bushing (first bushing means) 18
... Vertical column (support column) 31 ... Second base body 32 ... Bush (second bush means) 33 ...
Stop plate (second cover means) 34...Coolant receiving groove (first cover means) 34'...Vertical wall 35...Discharge vibrator (first discharge means) 37...Pneumatic inlet 40... Bearing 44... Table 50... Grinding wheel 51... Mounting plate (first plate) 64... Shaft 65... Clamp plate (second plate) 68... Enclosure (Third cover means) 69.
... Coolant recovery groove (refrigerant recovery path means) 70 ... Coolant storage tank (refrigerant storage means) 71 ... Compressed air source 72 ... O-ring 73 ... Filter/circulation pump Patent applicant International Tool Machines Incorporated

Claims (10)

[Claims] (1) A first base, a first slide member linearly slidable on the first base, and a second slide member linearly slidable on the first base. a slide member, a first bushing means fixed on the second slide member, a support column disposed within the first bushing means for predetermined reciprocating vertical sliding movement; a working means disposed on the working means, a driving means for driving the working means, and a second working means fixed on the first base body.
a base body, a bearing rotatably disposed within the second base body, a support shaft rotatably disposed within the bearing, and a support shaft rotatably fixed about a vertical axis on the support shaft. a workpiece holding table; a workpiece holding means disposed on the workpiece holding table for holding a workpiece for abutment with the processing means; a second bushing means arranged to extend through the first bushing means and the support column and having an inner diameter larger than an outer diameter of the first bushing means to permit lateral movement of the first bushing means; a first cover means fixed to surround the first bush means; and a second cover means fixed to the second bush means above the first cover means. a vertical wall means extending upwardly from the first cover means and joined to the bottom surface of the second cover means; a refrigerant storage means for storing refrigerant; a refrigerant dispersion means for dispersing a refrigerant toward a contact area between the means and the workpiece, and after the refrigerant cools the contact area between the work means and the workpiece, the first and second between the cover means and the refrigerant and the first
and a machine tool, wherein contact with the second slide member is prevented by the first and second cover means. (2) The machine tool according to claim 1, wherein the machine tool has a grinding wheel, and the machine tool is configured as a grinder. (3) The machine tool according to claim 2, wherein a first discharge means for discharging the refrigerant collected between the first and second cover means is disposed on the first cover means. (4) The machine tool according to claim 3, wherein a circulation means for circulating the refrigerant is connected to the first discharge means and the refrigerant storage means. (5) Third cover means capable of selectively surrounding the workpiece holding table, the refrigerant dispersing means, and the working means is removably placed on the second base, and the refrigerant dispersing means The dispersed refrigerant is retained within the third cover means, a portion of which passes through the second bushing means and is collected between the first and second cover means, and is collected between the first and second cover means. the refrigerant is recycled to the refrigerant storage means via a discharge means, and contact between the refrigerant and the first and second sliding members is prevented by the second base body and the third cover means; The machine tool according to claim 3. (6) A refrigerant recovery path means is provided on the second base body along a line of contact with the third cover means, and is connected to the refrigerant recovery path means on one side and the circulation means on the other side. Claim 5, wherein a second evacuation means is provided.
Machine tools listed. 7. The machine tool of claim 6, wherein said circulation means is provided with filter means for filtering contaminants from the refrigerant. (8) When the first cover means moves relative to the second cover means, the distance between the bottom surface of the second cover means and the vertical wall means of the first cover means Machine tool according to claim 1, characterized in that O-ring means are provided on the vertical wall means to improve sealing action. (9) A pneumatic inlet is provided in the second cover, and a compressed air source is connected to the pneumatic inlet, and compressed air from the compressed air source is supplied to the first and second covers from above through the pneumatic inlet. between the second cover means and the O
Machine tool according to claim 8, characterized in that it improves the sealing action between the ring means and the bottom surface of the second cover means. (10) A first plate on which the working means is fixed is fixed to the top surface of the support column, and a second plate is fixed to the top surface of the first bushing means;
and a second plate having an axially aligned bore formed therein and a shaft extending through the bore so that the machining means is angularly aligned relative to the first bushing. The machine tool according to claim 1, wherein the machine tool is prevented from performing movements.