GB1601010A

GB1601010A - Machine tool having a cleaning means

Info

Publication number: GB1601010A
Application number: GB1918778A
Authority: GB
Original assignee: Kearney and Trecker Corp
Current assignee: Kearney and Trecker Corp
Priority date: 1977-05-13
Filing date: 1978-05-12
Publication date: 1981-10-21
Also published as: BE866899A; DE2820165B2; JPS53141987A; AU510104B2; AU3527978A; CA1081503A; CH628268A5; DE2820165A1; CA1131948B; FR2390231A1; NL7805208A

Abstract

A feed line (60, 62) is attached to the machine-tool spindle (10) provided with an axial bore (40). A tool holder (26), likewise with an axial bore (50), is inserted into the spindle (10). The tool holder has a hollow probe in place of a tool. The probe can be inserted into holes in workpieces by the tool-positioning device. Compressed air is then fed to the tool holder via the feed line, and chips and coolant residues are blown out of the holes by means of the probe. <IMAGE>

Description

(54) MACHINE TOOL HAVING A CLEANING MEANS (71) We, KEARNEY & TRECKER CORPORATION, a corporation organized and existing under the laws of the State of Wisconsin, United States of America, of 11000 Theodore Trecker Way, West Allis, Wisconsin, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement.

This invention relates to machine tools of the type used to drill and/or tap holes in a workpiece. In such machine tools there is a problem of removing chips from the bottom of the holes, particularly after the holes are tapped, and this invention is addressed to that problem.

In the past, machine tools of the abovenoted type have been manufactured in which coolant is introduced through the tool via an axial duct in the spindle which mates with an axial duct in the toolholder or via a rotary gland on the toolholder. This invention is particularly adapted for use in combination with such coolant-through-the-tool machine tools and uses the existing coolant ducts for the additional function of blowing chips and coolant out of holes drilled and/or tapped in a workpiece.

According to the invention there is provided a machine tool comprising a rotatable and axially movable spindle, a conduit in the machine tool, a probe for cleaning a hole in a workpiece, the probe being removably received in the said spindle and provided with a central duct which communicates with the said conduit, the probe having an outer diameter smaller than the diameter of the hole to be cleaned, a source of compressed gas and a source of coolant or lubricant, and means for connecting the source of compressed gas to the said conduit when the said probe is in the spindle and for connecting the source of coolant or lubricant to the said conduit when there is received in the spindle a rotary cutting tool having an axial duct arranged to communicate with the said conduit.

In the accompanying drawings: Figure 1 is an axial sectional view of one preferred embodiment of the invention in combination with a coolant-through-thetool-type of machine tool; Figure 2 is an axial section view of one toolholder having a hollow probe for blowing chips and coolant out of holes in a workpiece; Figure 3 is a fragmentary perspective view, partially cut away, showing the probe of Figure 2 being used to blow chips and coolant out of a hole in a workpiece; Figure 4 is a plan view, partially cut away, of a second preferred embodiment of the invention in combination with a second coolant-through-the-tool-type of machine tool; Figure 5 is a cross-sectional view taken on the line 5-5 of Figure 4; Figure 6 is a cross-sectional view taken on the line 6-6 of Figure 4; and Figure 7 is a side elevational view taken on the line 7-7 of Figure 4.

Figure 1 is an axial sectional view of the spindle 10 of a horizontal machining center.

Spindle 10 is journalled within a spindle head 12 by bearings 14, 16 and 18 and is rotated by motor means (not shown) through a drive gear 20 which is rigidly attached to spindle 10. Spindle head 12, which is represented by fragments in Figure 1, is conventional in every respect, as are the remaining portions of the machining center which are not shown in Figure 1. The outer portions of spindle 10 are conventional in structure but the inner portions have been modified for the purposes of this invention.

The inner portion of spindle 10 has an axial bore 22 which extends the full length of spindle 10 and opens at one end into a toolholder socket 24 which is shaped to receive conventional toolholders. A toolholder 26 which has been modified for the purposes of this invention is shown mounted in toolholder socket 24 and clamped therein by a draw in clamp 28 which engages a retention knob 30 on the inner end of toolholder 26. The forward portion of toolholder 26 is disclosed in Figure 2 and will be described after the inner portion of spindle 10 is described.

A cylindrical drawbolt 32 is axially slidably mounted within spindle bore 22 for movement between a retracted position, shown in Figure 1, and an extended position, in which drawbolt 32 is moved to the left in Figure 1. Drawbolt 32 is spring biased to its retracted position by a stack of Belleville springs (not shown) which urge drawbolt 32 to the right in Figure 1. A hydraulic cylinder (not shown) is provided for moving drawbolt 32 to its extended position (to the left in Figure 1) against the force of the Belleville springs by bumping against an adjustable sleeve 34 on the inner end of drawbolt 32. Sleeve 34 can be adjusted and locked in place by a setscrew 36 to regulate the extended position of drawbolt 32.

Clamp 28 is attached to the outer end of drawbolt 32. Clamp 28 includes a slotted sleeve 38 which has internal screw threads 40 on one end (to the right in Figure 1) and jaw elements 42 on the other end. Slotted sleeve 38 is made of spring material and jaw elements 42 are spring biased thereby outwardly but are moved inwardly when drawbolt 32 is moved to its retracted position by interaction with a collar 44. The inner surface of collar 44 and the outer surface of jaw elements 42 are shaped to cam jaw elements 42 together when drawbolt 32 is moved to its retracted position, shown in Figure 1, thereby clamping jaw elements 42 onto retention knob 30. When drawbolt 32 is moved to its extended position (to the left in Figure 1) the cam surfaces allow jaw elements 42 to open due to spring tension and release retention knob 30.

Drawbolt 32 has a central axial duct 46 extending therethrough and has an insertion tube 48 on the outer end thereof which is coupled on one end to duct 46 and is positioned to be inserted on the other end into an opening 50 in the retention knob 30 of toolholder 26. Insertion tube 48 is clamped to the outer end of drawbolt 32 by a threaded sleeve 52 which is attached to the outer end of drawbolt 32 by screw threads 54. An O-ring 56 on the inner end of insertion tube 48 seals the inner end of tube 48 and also provides a small amount of play to compensate for small mismatches in the position of insertion tube 48 and the opening 50 in retention knob 30.

On the other end of drawbolt 32, a conventional rotary union 58 having two inlet conduits 60 and 62, one for compressed air and the other for coolant, is coupled to drawbolt 32 and to duct 46 therein. Conduit 62 is coupled to a source of coolant fluid (not shown) and to a conventional coolantthrough-the-tool solenoid valve 63. The coolant pump and distribution system is conventional in structure and function and hence is omitted from the drawings. Conduit 60 is coupled to a compressed air tank 64 through a conventional solenoid valve 66.

When solenoid valve 66 is opened, compressed air is admitted through conduit 60 and rotary union 58 into duct 46 and from duct 46 through insertion tube 48 into the opening 50 in retention knob 30. This compressed air is used to blow chips and coolant out of holes in a workpiece through a modified toolholder shown in Figures 2 and 3.

Referring to Figure 2, toolholder 26 has an axial duct 68 which opens into opening 50 in retention knob 30 and extends through toolholder 26. A hollow, elongated cylindrical probe 70 is mounted in the front end of duct 68 and is held therein by a setscrew 72. Probe 70 has a slender front portion 74 which is dimensioned to fit within the holes which are to be cleaned and has a nozzle 75 on its outer end. Figure 3 shows the front portion 74 of probe 70 inserted into a hole 76 in a workpiece 78 with nozzle 75 being near the bottom of hole 76. With the probe 70 in this position, compressed air is forced through probe 70 by the means described above to blow chips and coolant out of hole 76. When the compressed air is initially applied to rotary union 58, there may be some coolant in duct 46 from a preceding coolant-through-the-tool operation, and this will be blown out of duct 46 and then out of hole 76 by the compressed air. Within a short space of time, the compressed air will blow both coolant and chips out of hole 76.

The modified toolholder 26 of this invention has a standard outer configuration including an automatic toolchanger flange 80 and can be handled by a conventional automatic tool changer. Other tools used in combination with modified toolholder 26 have an opening 50 in their retention knob 30 to accommodate the end of insertion tube 48. Positioning of probe front portion 74 into the hole to be cleaned out is accomplished by the conventional positioning controls for the machining center. This may be done by moving spindle head 12 with respect to workpiece 78, or by moving workpiece 78 with respect to spindle head 12, or by a combination of both.

Figures 4 through 7 show a second preferred embodiment for use in combination with a coolant-through-the-tool-type of machine tool in which the coolant is introduced through a rotary gland in the toolholder rather than through an axial duct in the spindle. Referring to Figure 4, the toolholder 82 for this embodiment is substantially cylindrical in shape and is shown clamped into a spindle 84 which is rotatably mounted by conventional means not shown in a spindle head 86. A spindle ring 88 is rigidly attached to spindle head 86 by bolts 90 (Figure 5). Spindle ring 88 surrounds spindle 84 and serves as a support for the coolant conduit and socket as described in later paragraphs. The portions of the machine tool which support spindle 84 and spindle head 86 are conventional in structure and hence are not shown in the drawings.

A coolant and air supply block 92 having a coolant and air socket 94 therein is bolted to spindle ring 88 adjacent to spindle 84. A coolant and air supply conduit 96 is attached to supply block 92 and is coupled to socket 94 by duct 98 (Figure 7). Coolant is supplied to conduit 96 from a conventional coolant supply (not shown) which contains valves (not shown) for also routing compressed air to conduit 96 which also serves as a compressed air conduit for the purposes of this invention. The coolant is introduced into conduit 96 when a conventional coolant through-the-tool toolholder is used and the compressed air is introduced into conduit 96 when a modified coolant-through-the tool toolholder 82 (shown in Figures 4-7) is used to blow chips and coolant out of a drilled and tapped hole.

Toolholder 82 is modified by means of a rotary gland 100 through which a fluid (either coolant or compressed air) is supplied to the toolholder while it is rotating.

Rotary gland 100 is seated in a substantially rectangular gland block 102 which has a bore 104 therein (Figure 4) for receiving toolholder 82. A pair of bushings 106 and 108 rotatably support toolholder 82 within bore 104. Bushings 106 and 108 are spaced apart axially to form a gap 110 into which coolant or compressed air is forced. 0-rings 112 and 114 on the interior surface of bushings 106 and 108 seal in the coolant or compressed air at the rotary junction between bushings 106 and 108 and toolholder 82. Bushing 108 is held in place by a flange 116 on toolholder 82 and bushings 106 is held in place by a snap ring 118.

A radial opening 120 in toolholder 82 communiates between annular gap 110 and an axial duct 122 in toolholder 82. Axial duct 122 is coupled to a radial duct 124 which in turn is coupled to a central axial duct 126 in a probe 128 which is removably held in toolholder 82 by a setscrew 130.

Probe 128 has a slender elongated outer end 132 which terminates in a nozzle 134. In the operation of this embodiment, compressed air is forced from gap 110 through opening 120 and through ducts 122, 124, and 126 out nozzle 134 to blow chips and coolant out of a drilled and/or tapped hole into which probe end 132 is inserted. However, with a coolant-through-the-tool type of tool inserted into toolholder 82 in place of probe 128, coolant can be conducted from gap 110 through opening 120 and ducts 122, 124 to the coolant-through-the-tool tool.

The connection between coolant socket 94 and gap 110 is effected by a coupling tube 136 which is mounted in a block 138 attached to a gland block 102 and is coupled to gap 110 through a duct 140 in block 102.

Coupling tube 136 has an 0-ring 142 which interacts with bushing 144 to seal the connection between socket 94 and coupling tube 136. Either coolant or compressed air can be conducted from socket 94 to gap 110 via tube 136 and duct 140.

To effect correct alignment between coupling tube 136 and socket 94, an alignment pin 146 is moved into and out of a notch 147 (Figure 6) in an adjacent flange 148 of toolholder 82 to lock toolholder 82 in a predetermined angular position with respect to gland block 102 when it is stored in the tool magazine (not shown) or is being moved between the tool magazine and spindle 84. Alignment pin 146 is attached to plunger 150 which is slideable in an axial bore 152 in block 138 and is normally spring biased inwardly by a compression spring 154. An abutment 156 opposite the inner end of plunger 150 bears thereagainst to move alignment pin 146 away from flange 148 when toolholder 82 is mounted in spindle 84. When toolholder 82 is removed from spindle 84, spring 154 forces plunger 150 inwardly and causes alignment pin 146 to engage notch 147 in flange 148.

An annular splash shield 158 is attached to the front of gland block 102 around toolholder 82 to limit the splashing of chips and coolant regardless of whether coolant or compressed air is being applied to toolholder 82.

WHAT WE CLAIM IS: 1. A machine tool comprising a rotatable and axially movable spindle, a conduit in the machine tool, a probe for cleaning a hole in a workpiece, the probe being removably received in the said spindle and provided with a central duct which communicates with the said conduit, the probe having an outer diameter smaller than the diameter of the hole to be cleaned, a source of compressed gas and a source of coolant or lubricant, and means for connecting the source of compressed gas to the said conduit when the said probe is in the spindle and for connecting the source of coolant or lubri

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. a coolant-through-the-tool-type of machine tool in which the coolant is introduced through a rotary gland in the toolholder rather than through an axial duct in the spindle. Referring to Figure 4, the toolholder 82 for this embodiment is substantially cylindrical in shape and is shown clamped into a spindle 84 which is rotatably mounted by conventional means not shown in a spindle head 86. A spindle ring 88 is rigidly attached to spindle head 86 by bolts 90 (Figure 5). Spindle ring 88 surrounds spindle 84 and serves as a support for the coolant conduit and socket as described in later paragraphs. The portions of the machine tool which support spindle 84 and spindle head 86 are conventional in structure and hence are not shown in the drawings. A coolant and air supply block 92 having a coolant and air socket 94 therein is bolted to spindle ring 88 adjacent to spindle 84. A coolant and air supply conduit 96 is attached to supply block 92 and is coupled to socket 94 by duct 98 (Figure 7). Coolant is supplied to conduit 96 from a conventional coolant supply (not shown) which contains valves (not shown) for also routing compressed air to conduit 96 which also serves as a compressed air conduit for the purposes of this invention. The coolant is introduced into conduit 96 when a conventional coolant through-the-tool toolholder is used and the compressed air is introduced into conduit 96 when a modified coolant-through-the tool toolholder 82 (shown in Figures 4-7) is used to blow chips and coolant out of a drilled and tapped hole. Toolholder 82 is modified by means of a rotary gland 100 through which a fluid (either coolant or compressed air) is supplied to the toolholder while it is rotating. Rotary gland 100 is seated in a substantially rectangular gland block 102 which has a bore 104 therein (Figure 4) for receiving toolholder 82. A pair of bushings 106 and 108 rotatably support toolholder 82 within bore 104. Bushings 106 and 108 are spaced apart axially to form a gap 110 into which coolant or compressed air is forced. 0-rings 112 and 114 on the interior surface of bushings 106 and 108 seal in the coolant or compressed air at the rotary junction between bushings 106 and 108 and toolholder 82. Bushing 108 is held in place by a flange 116 on toolholder 82 and bushings 106 is held in place by a snap ring 118. A radial opening 120 in toolholder 82 communiates between annular gap 110 and an axial duct 122 in toolholder 82. Axial duct 122 is coupled to a radial duct 124 which in turn is coupled to a central axial duct 126 in a probe 128 which is removably held in toolholder 82 by a setscrew 130. Probe 128 has a slender elongated outer end 132 which terminates in a nozzle 134. In the operation of this embodiment, compressed air is forced from gap 110 through opening 120 and through ducts 122, 124, and 126 out nozzle 134 to blow chips and coolant out of a drilled and/or tapped hole into which probe end 132 is inserted. However, with a coolant-through-the-tool type of tool inserted into toolholder 82 in place of probe 128, coolant can be conducted from gap 110 through opening 120 and ducts 122, 124 to the coolant-through-the-tool tool. The connection between coolant socket 94 and gap 110 is effected by a coupling tube 136 which is mounted in a block 138 attached to a gland block 102 and is coupled to gap 110 through a duct 140 in block 102. Coupling tube 136 has an 0-ring 142 which interacts with bushing 144 to seal the connection between socket 94 and coupling tube 136. Either coolant or compressed air can be conducted from socket 94 to gap 110 via tube 136 and duct 140. To effect correct alignment between coupling tube 136 and socket 94, an alignment pin 146 is moved into and out of a notch 147 (Figure 6) in an adjacent flange 148 of toolholder 82 to lock toolholder 82 in a predetermined angular position with respect to gland block 102 when it is stored in the tool magazine (not shown) or is being moved between the tool magazine and spindle 84. Alignment pin 146 is attached to plunger 150 which is slideable in an axial bore 152 in block 138 and is normally spring biased inwardly by a compression spring 154. An abutment 156 opposite the inner end of plunger 150 bears thereagainst to move alignment pin 146 away from flange 148 when toolholder 82 is mounted in spindle 84. When toolholder 82 is removed from spindle 84, spring 154 forces plunger 150 inwardly and causes alignment pin 146 to engage notch 147 in flange 148. An annular splash shield 158 is attached to the front of gland block 102 around toolholder 82 to limit the splashing of chips and coolant regardless of whether coolant or compressed air is being applied to toolholder 82. WHAT WE CLAIM IS:

1. A machine tool comprising a rotatable and axially movable spindle, a conduit in the machine tool, a probe for cleaning a hole in a workpiece, the probe being removably received in the said spindle and provided with a central duct which communicates with the said conduit, the probe having an outer diameter smaller than the diameter of the hole to be cleaned, a source of compressed gas and a source of coolant or lubricant, and means for connecting the source of compressed gas to the said conduit when the said probe is in the spindle and for connecting the source of coolant or lubri

cant to the said conduit when there is received in the spindle a rotary cutting tool having an axial duct arranged to communicate with the said conduit.

2. A machine tool according to Claim 1, comprising means for positioning said spindle with respect to said workpiece to insert said probe into the said hole in said workplece.

3. A machine tool according to Claim 1 or 2, wherein said connecting means comprises a rotary union coupled to said first conduit, to said source of compressed gas and to said source of coolant or lubricant, and means for controlling application of said compressed gas and coolant or lubricant to said rotary union.

4. A machine tool according to Claim 1 or 2 comprising a toolholder rotatably mounted in a block, and wherein the central duct in the probe communicates with the said conduit via a rotary gland coupled between said block and said toolholder.

5. A machine tool substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings.

6. A machine tool substantially as herein described with reference to Figures 4 to 7 of the accompanying drawings.