US3748788A

US3748788A - Control device for a grinding machine

Info

Publication number: US3748788A
Application number: US00176993A
Authority: US
Inventors: G Koppenwallner
Original assignee: Fortuna Werke Maschinenfabrik GmbH
Current assignee: Fortuna Werke Maschinenfabrik GmbH
Priority date: 1970-09-05
Filing date: 1971-09-01
Publication date: 1973-07-31
Anticipated expiration: 1990-07-31
Also published as: GB1336354A; FR2107254A5; DE2044147A1

Abstract

A grinding machine having a grinding disc with a hood. A dressing device is associated with the disc and the hood has a moveable part with a coolant nozzle thereon which supplies coolant to the working region of the disc. Drives are provided to move the dressing device toward and away from the wheel and to adjust the position of the part of the hood and the coolant nozzle and are so interconnected that the coolant nozzle is adjusted in position each time the dressing device dresses the disc whereby the coolant is always directed to the proper region.

Description

United States Patent Koppenwallner 5] July 31, 197 3 [54] CONTROL DEVICE FOR A GRINDING 3,641,714 2/1972 Hiroaki 51/165137 MACHINE [75] Inventor' 53: ggf zg der Primary Examiner0thell M. Simpson Att0rneyWalter Becker [73] Assignee: Fortuna-Werke Maschinenfabrik 7 AG, Stuttgart-Bad Cannstatt,

: Germany [22] Filed: Sept. 1, 1971 ABSTRACT [211 App]. N9" 176,993 A grinding machine having a grinding disc with a hood. A dressing device is associated with the disc and the Foreign Aliplicafion Priority Data hood has a moveable part with a coolant nozzle thereon Sept. 5, 1970 Germany P 20 44 147.8 which supp es coo ant to the wo g eg o of the disc. Drives are provided to move the dressing device [52] US. Cl 5l/l65.87, 51/356, 125/11 R toward and away from the wheel and to adjust the posi- [51] Int. Cl B24b 49/00, B24b 55/02 tion of the p r f the hood n h coolant nozzle and [58] Field of Search 51/165.87, 165.89, are o interconnected that the coolant nozzle is ad- 51/356; 125/1 1 R, 1 1 NT justed in position each time the dressing device dresses the disc whereby the coolant is always directed to the [5 References Cited proper region.

UNITED STATES PATENTS 11/1964 Fant et a1 51/165.87

15 Claims, 3 Drawing Figures PAIENIEU JUL3 1 191a SHEEY 1 OF 3 PATENIED JUL 3 1 I973 SHEET 3 BF 3 CONTROL DEVICE FOR A GRINDING MACHINE The present invention relates to a control device for a grinding machine and, more specifically, for the feeding device of a dressing apparatus. Devicesof this type, for instance, with dressing diamonds, diamond rolls, or steel rolls, are generally employed in grinding machines for restoring the sharpness and true shape of the grind ing disc. The feeding of the dressing tool is with the individual post-machining 'operations respectively effected by relatively small amounts, but taking into consideration the life span of a grinding disc, correspondingly long total feeding strokes result in view of the generally high volume of wear.

Aside from the dressingapparatus, the grinding machines are equipped with various machine elements which have to be adjusted in conformity with the diameter of the grinding disc. In this connection there may be mentioned so-called cover elements, such as caps,

slides, or the like, which are arranged within the region of the grinding disc and which are joumalled on the protective hood for the grinding disc and are supposed alwaysto maintain as slight a distance aspossible from the circumference of the grinding disc. In this connection there may also be mentioned the customary feeding means for the coolant which likewise must have a predetermined distance from the circumference of the grinding disc. The post-setting of the above mentioned machine elements requires considerable service and sometimes even requires a stoppage of the operation while in addition thereto the operator has to pay considerable attention to these machine elements. Therefore, it would be desirable to have the adjustment of machine elements of the above mentioned type effected automatically in conformity with the respective diameter of the grinding disc.

Consequently, it is an object of the present invention to provide a control'device which, while relatively simple in construction, will automatically adjust machine elements in conformity with the diameter of the grinding disc.

This object and other objects and advantages of the invention will appear more clearly from the following specifications in connection with the accompanying drawings, in which:

FIG. 1 diagrammatically illustrates a vertical section perpendicular to the grinding spindle axis through a circular grinding machine with a dressing device and with adjustable protective hood cap according to the invention.

FIG. 2 diagrammatically illustrates a section through the machine of FIG. I along a vertical plane.

FIG. 3 is a control and operating diagram of the control device according to the invention for adjusting a dressing device and a protective hood cap according to FIG. 1 and 2.

The control device according to the invention for the feeding device of a dressing apparatus is characterized primarily in that the feeding device is with regard to its movement relative to the grinding device coupled to the adjusting device of a machine element, especially a hood and/or a coolant supply means, in conformity with the diameter of the grinding disc.

In other words, the invention takes advantage of the high precision of the already present control device for feeding the dressing means for adjusting other machine parts or elements in conformity with the diameter of the grinding disc. The required additional structural elements are relatively few because, aside from the adjusting device necessary at any rate in connection with automation with pertaining drive of the adjustable machine element, only a coupling or synchronization of the dressing-feeding device on one hand and the adjusting device of the adjustable machine element on the other hand are additionally required.

Referring now to the drawings in detail and FIGS. 1 and 2 thereof in particular, the cylindrical grinding machine illustrated therein comprises a head stock 1 which is fixedly arranged on the machine bed 17 and has a grinding spindle 2 inserted therein. Spindle 2 is coupled to a driving unit 3 and carries a grinding disc 4. The grinding disc 4 is arranged within a protective hood 8 which by means of supporting flanges 5 and 6 is connected to the machine bedl7. Those parts of the protective hood 8 which are connected to the two supporting flanges 5 and 6 are adapted in the axial direction of the grinding spindle to be separated from each other so that the supporting flange 6 after having been disconnected from the machine can be displaced in the right-hand directionwith regard to FIG. 2 for purposes of exchanging the grinding disc. The outer machine cover 7 is at the right-hand operating side (with regard to FIG. 1) provided with an outer hood 14 which is adapted to be moved in upward direction to the position indicated by dot-dash lines. For purposes of opening and closing the hood 8, there is within the machine cover provided a transmission 15 with gear rack 15a and with a gear 15b which is stationarily joumalled with regard to the frame, and with a pivotal arm 15c pivotally connected to outer hood 1'4 and with a driving cylinder 15d. As support for the work piece, according to the specific embodiment illustrated, there is provided a carriage 16 with a work piece support 160. The carriage 16 is arranged below the stationary grinding wheel head 1 and is displaceable in a direction trans verse to the grinding spindle axis.

As will be seen from FIGS. 1 and 2, a cap 9 is arranged on the protective hood 8 and has its lateral parts 10 and extend around the upper and front section of the protective hood 8. Cap 9 is adapted to be displaced in the direction transverse to the grinding spindle axis as indicated by the arrow A in FIG. 1. The lower front edge 9a of cap 9 which is arranged within the region of the working opening of hood 8 on the work piece side should be kept at a predetermined slight distance from the circumference of the grinding disc 4 and, more specifically, in conformity with the decreasing grinding diameter in the direction of the arrow A. When inserting a new or larger grinding disc, cap 9 is returned to its corresponding starting position. On the front side of cap 9 there is within the region of the edge provided a feeding device 9b for a coolant, the mouth of the cooling device which points downwardly should likewise be kept at a predetermined distance from the circumference of the grinding disc. The feed ing device for the coolant will to this end take part in the adjusting movement of cap 9.

A separate adjusting device 12 with a threaded drive in the form of a threaded spindle l3 and a nut 13a connected to the cap 9 is provided for the latter. This adjusting device is, in a manner to be described further below, connected to the feeding device 20 of a dressing apparatus 18 which is arranged behind the grinding disc. The dressing tool 19 of the device 18 extends through a cutout in the rear wall of the protective hood 8 and is adapted to be displaced in the direction of the arrow B (FIG. 1) for engagement with the circumference of the grinding disc.

As diagrammatically illustrated in FIG. 3, the feeding device of the dressing apparatus 18 comprises a fast traverse feeding device 21 in the form of a fluidoperable cylinder piston system, and also comprises a fine adjusting device 22 in the form of a screw drive with threaded spindle 22a and nut 22b which is connected to the dressing tool carrier 19a and is connected to the piston rod of the fluid-operable cylinder piston system 21. By means of the fast traverse feeding device, the tool carrier 19a is, in conformity with arrow B, advanced to a starting position for a dressing operation. This starting position is determined by a non-variable abutment position of the piston in the cylinder piston system 21 and by the respective relative position between spindle 22a and nut 22b. Inasmuch as the starting position for each dressing operation simultaneously represents the end position of the preceding dressing operation, which end position was reached by a corresponding rotation of the spindle, the fine feeding of the tool carriage 19a is effected during the dressing operations following each other always only in the direction of the arrow B and, more specifically, independently of the advance and return strokes of the fast traverse feeding device carried out between the individual dressing operations. For this reason, the fine feeding device also is suited as position indicator for a successive postguiding of cap 9 in conformity with the decreasing diameter of the grinding disc.

As drive for the fine feeding device, according to the specific showing in the drawings, a pawl ratchet mechanism 3 with ratchet wheel 23a and pawl 23b as well as with a lifting element in the form of a fluid-operable cylinder piston system 230 is provided. The ratchet wheel 23a is through the intervention of a diagrammatically indicated drive connection 24 connected to a stepdown transmission 25 which latter comprises a drive wheel 25a for the spindle 22a of the fine feeding device.

For purposes of limiting the stroke of the pawl 23b in conformity with different feeding end positions of the dressing tool 19, there is provided an adjustable abutment device 26 with two abutments 26a, 26b respectively adjustable by two fluid-operable cylinders between two positions. By means of these two abutments, it is possible to adjust a total of three different feeding end positions I, II and III of the pawl 13b.

The adjusting device 12 of cap 9 is as to its drive synchronous with the fine feeding device of the dressing apparatus. This may be realized, according to the specific showing in FIG. 3, by a direct connection of the spindle 13 through the intervention of a stepdown transmission 12 and a coupling 12b with the transmission connection 24 of the fine feeding device 22. Inversely, as likewise indicated in FIG. 3, for the adjusting device 12 of cap 9 there may be provided a pawl ratchet mechanism 27 which, as assumed in the specific embodiment, may as to all details correspond to the ratchet mechanism 23 of the fine feeding device of the dressing tool so that a further description of the ratchet mechanism 27 does not appear to be necessary.

The synchronization between adjusting device 12 and fine feeding device 22 is in the last mentioned instance effected by a common feeding control device 28 of thefluid-operable cylinder piston systems pertaining to the two

ratchet mechanisms

23 and 27. A corresponding common control circuit 29 is provided for the equal stroke limitation of the pawls.

If the adjusting device 12 has a drive of its own, for instance in the form of a pawl ratchet mechanism 27, the pawl ratchet mechanism or a corresponding different drive for the fine feeding device may be omitted. In such an instance the coupling 12b will take over the synchronization and will also simultaneously effect the drive of the fine feeding device. Such a design has the advantage that only one single driving device for the fine feeding device and for the adjusting device will be necessary and this holds true also for a plurality of exchangeable dressing devices. These dressing devices will in such an instance require primarily only the screw drive of the fine feeding device. The coupling 12b is for such exchange of the dressing device expediently designed as plug coupling or another easily detachable design. In certain circumstances, however, it may be necessary and expedient to provide the dressing device with fast traverse and fine feeding means including a pawl ratchet mechanism or the like in the form of exchangeable structural units as has been indicated in FIG. 3 by the dot-dash line 30. For purposes of exchanging the grinding disc, it is merely necessary to open up the feeding and control connections of the pawl ratchet mechanisms.

In connection with the present invention, particular importance is attached to a safe mounting and guiding of the adjustable cap 9 in case the grinding disc should break. Inasmuch as it is practically impossible to provide such a rigid design of the anchoring of the cap 9 that it will be able towithstand or absorb such high load, an energy consuming anchoring or connection is to be preferred which in case of a break of spindle 13 or of another driving element of the cap 9 will convert into a deforming work the energy of movement of the cap which is thrown forwardly by pieces of the broken grinding disc. To this end, as shown in FIG. 1, the lateral part of cap 9 is provided with a guiding connection having a slot 31 and pin 32. The pin 32 is connected to the lateral wall of hood 8 which wall is located below pin 32. Pin 32 supports cap 9 in vertical direction. Within the region of the rear pin position within the slot, which position corresponds to the cap position farthest away from the grinding disc, there is provided a slot support 33 which tapers in a wedge-like manner to less than the diameter of the pin. It is into this slot section 33 that the pin will be pressed successively when cap 9 which is torn loose is thrown toward the front. In this connection a considerable amount of kinetic energy is converted into deforming work and is thus made harmless with regard to possible further damage to the machine.

It is, of course, to be understood that the present invention is, by no means, limited to the particular showing in the drawings but also comprises any modifications within the scope of the appended claims. What is I claimed is:

1. In a grinding machine having a grinding disc, a

means connected to said dressing device for adjustment thereof, second means connected to said element for adjustment thereof, and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, a hood for the grinding disc respectively a coolant supply nozzle mounted to direct coolant to the working region of the grinding disc, said hood respectively said nozzle comprising said element.

2. In a grinding machine having a disc, a dressing device for the grinding disc and an element separate from said dressing device and adjustable in conformity with the diameter of the grinding disc, said element comprising a hood for the grinding disc and a coolant supply nozzle mounted to direct coolant to a working region of the grinding disc, first means connected to said dressing device for adjustment thereof, second means connected to said element for adjustment thereof, and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, said first means comprising a fast traverse feed means and a fine feed means operable sequentially, said third means operatively only connecting said second means to said fine feed means.

3. A grinding machine according to claim 2 in which said fast traverse feed means is in the form of a cylinder-piston system and said fine feed meansis in the form of a screw drive system coupled thereto, said cylinder-piston system having fixed end positions, said third means operatively connecting said screw drive system to said second means.

4. In a grinding machine having a grinding disc, a dressing device for the disc and an element separate from said dressing device and adjustable in conformity with the diameter of the disc; first means connected to said dressing device for adjustment thereof, second means connected to said element for adjustment thereof, and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, a hood for said disc, said hood having a movable part and a coolant supply nozzle mounted thereon to direct coolant to the working region of the disc, said part and nozzle comprising said element, said second means comprising an adjusting screw threadedly engaging said element, said first means comprising a fast traverse feed means and a fine feed means, and said third means connecting said adjusting screw to said fine feed means.

5. A grinding machine according to claim 4 in which said fast traverse feed means comprises a cylinder and a piston reciprocable therein, a feed screw connected to the piston and a nut on the feed screw connected to the dressing device, said third means operatively interconnecting said feed screw and said adjusting screw.

6. A grinding machine according to claim 5 in which said third means comprises a geared transmission.

7. A grinding machine according to claim 5 which includes a ratchet wheel, a geared transmission connecting said ratchet wheel to said feed screw, a drive pawl for the ratchet wheel, and stroke drive means connected to said pawl for the actuation thereof.

8. A grinding machine according to claim 7 which includes adjustable abutment means operatively associated with said stroke drive means for controlling the stroke thereof thereby to control the fine feeding of said dressing device.

9. A grinding machine according to claim 8 in which said abutment means includes a plurality of abutments at least one of which is selectively moveable between effective and ineffective positions.

10. A grinding machine according to claim 5 which includes a ratchet disc connected to said adjusting screw, drive pawl means for said ratchet wheel, and stroke drive mechanism connected to said pawl means for the actuation thereof.

11. A grinding machine according to claim 10 which an adjustable abutment device operatively associated with said stroke drive mechanism to control the adjustment of said element.

12. A grinding machine according to claim 11 in which said-abutment device comprises a plurality of abutment elements at least one of which is selectively moveable between effective and inefiective positions.

13. A grinding machine according to claim 5 which includes a ratchet wheel connected to each of said adjusting screw and feed screw, a drive pawl for each ratchet wheel, a stroke drive means connected to each pawl for the actuation thereof, and means for simultaneously controlling both of said stroke drive means.

14. A grinding machine according to claim 4 in which said dressing device and said fine feed means form a single exchangeable structural unit.

15. In a grinding machine having a grinding disc, a dressing device for the disc and an element separate from said dressing device and adjustable in conformity with the diameter of the disc; first means connected to said dressing device for adjustment thereof, second means connected to said element for adjustment thereof,.and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, a hood enclosing at least a portion of said disc, said hood hav-- ing a movable part and a coolant supply nozzle on said part, said movable part and nozzle comprising said element, pin and slot means guidingly connecting said hood and said part thereof, said slot extending in the direction of adjustment of said part and tapering inwardly in the direction in which the pin moves therein as said part moves away from saiddisc, said slot tapering inwardly to a dimension smaller than the diameter of said pin.

. i i l

Claims

1. In a grinding machine having a grinding disc, a dressing device for the grinding disc and an element separate from said dressing device and adjustable in conformity with the diameter of the grinding disc; first means connected to said dressing device for adjustment thereof, second means connected to said element for adjustment thereof, and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, a hood for the grinding disc respectively a coolant supply nozzle mounted to direct coolant to the working region of the grinding disc, said hood respectively said nozzle comprising said element.

3. A grinding machine according to claim 2 in which said fast traverse feed means is in the form of a cylinder-piston system and said fine feed means is in the form of a screw drive system coupled thereto, said cylinder-piston system having fixed end positions, said third means operatively connecting said screw drive system to said second means.

12. A grinding machine according to claim 11 in which said abutment device comprises a plurality of abutment elements at least one of which is selectively moveable between effective and ineffective positions.

15. In a grinding machine having a grinding disc, a dressing device for the disc and an element separate from said dressing device and adjustable in conformity with the diameter of the disc; first means connected to said dressing device for adJustment thereof, second means connected to said element for adjustment thereof, and third means operatively interconnecting said first and second means for correlating the adjustments of said dressing device and said element, a hood enclosing at least a portion of said disc, said hood having a movable part and a coolant supply nozzle on said part, said movable part and nozzle comprising said element, pin and slot means guidingly connecting said hood and said part thereof, said slot extending in the direction of adjustment of said part and tapering inwardly in the direction in which the pin moves therein as said part moves away from said disc, said slot tapering inwardly to a dimension smaller than the diameter of said pin.