Drilling device with oil supply unit

A drilling device having an oil supply tank disposed at a position where the oil supply tank is less likely to collide with surrounding objects. This device includes a fixing member (12) fixed to a workpiece, a column (14) extending upward from the fixing member, a tubular slide unit (16) that is slidable along the column, a tool body (18) disposed on the tubular slide unit, and an oil supply tank (20) provided between the tool body and the fixing member and removably fixed to the tubular slide unit. The tool body is provided with a cutting oil supply passage having a cutting oil inlet (109) disposed toward the fixing member, while the oil supply tank is provided with a cutting oil outlet disposed upward. The tool body is displaced upward on the column and the oil supply tank is moved close to the tool body from the lower side of the tool body, whereby the cutting oil outlet of the oil supply tank is connected to the cutting oil inlet of the tool body.

TECHNICAL FIELD

The present invention relates to a drilling device with an oil supply unit.

BACKGROUND ART

There is known a drilling device including a fixing member fixable to a workpiece by means of an electromagnet and a cutting oil supply unit for supplying cutting oil to a cutting tool (see Japanese Unexamined Patent Application Publication No. 2006-061993).

A cutting oil supply unit in such a drilling device has an oil supply tank, which tends to collide with surrounding objects to be damaged in transportation and use of the drilling device. Therefore, it is required that the oil supply tank be disposed at a position where the oil supply tank is less likely to suffer such damage.

In a cutting tool disclosed in the above-mentioned Japanese Unexamined Patent Application Publication No. 2006-061993, an oil supply tank is configured to be disposed in a space between an electromagnetic fixing member and a cutting edge drive unit attached above the fixing member.Patent Document 1: Japanese Unexamined Patent Application Publication No. 2006-061993Patent Document 2: Japanese Unexamined Patent Application Publication No. 2007-132252

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

In the drilling device disclosed in Japanese Unexamined Patent Application Publication No. 2006-061993, the oil supply tank is disposed as described above and therefore is less likely to be damaged. However, damage is unavoidable, and thus the oil supply tank needs to be replaced appropriately. Therefore, it is necessary to enable the oil supply tank to be easily replaced as well as to be surely connected to an oil supply passage of a tool body.

It is an object of the present invention to provide a drilling device with an oil supply tank which enables such replacement and connection.

Means for Solving the Problems

The present invention provides a drilling device with an oil supply unit which includes a fixing member configured to be removably fixed to a workpiece, a column extending upward from the fixing member, a tubular slide unit provided around the column so as to be slidable along the column, a tool body connected to the upper end portion of the tubular slide unit, and an oil supply tank provided between the tool body and the fixing member and removably fixed to the tubular slide unit. The tool body includes a cutting tool and a cutting oil supply passage which has a cutting oil inlet for receiving cutting oil from the oil supply tank and feeds the received cutting oil to the cutting tool. The cutting oil inlet is directed downward toward the fixing member. The oil supply tank has a cutting oil outlet directed upward and fluidly connected to the cutting oil inlet. The oil supply tank is configured to be moved toward the tool body, which has been displaced upward on the column from the lower side of the tool body while the cutting oil outlet is aligned with the cutting oil inlet in the vertical direction so that the cutting oil outlet of the oil supply tank is connected to the cutting oil inlet of the tool body.

In this drilling device, in a state in which the tool body is at the upper position, the oil supply tank can be easily attached. In a state in which the tool body is moved back to the lower position such that the oil supply tank is sandwiched between the tool body and the fixing member, the oil supply tank can be securely fixed and suppressed from being damaged by collision with surrounding objects. In attaching the oil supply tank, the oil supply tank is set under the tool body and then moved upward. Therefore, it is possible to reduce lateral protuberances of the oil supply tank and thus to further suppress the above-mentioned damage of the tank.

Further, this drilling device may be arranged as follows. The tool body includes a pressurized air supply unit. The pressurized air supply unit has a pressurized air supply passage for supplying pressurized air to the oil supply tank. The pressurized air supply passage has a pressurized air outlet connected to the oil supply tank. The pressurized air outlet is directed downward toward the fixing member. The oil supply tank has a pressurized air inlet directed upward and communicated with the pressurized air outlet. The oil supply tank receives pressurized air from the pressurized air supply unit to pressurize the inside of the oil supply tank so that cutting oil is discharged from the cutting oil outlet and supplied through the cutting oil supply passage to the cutting tool. The oil supply tank is configured to be moved toward the tool body, which has been displaced upward on the column, from the lower side of the tool body in a state in which the cutting oil outlet and the pressurized air inlet are aligned with the cutting oil inlet and the pressurized air outlet in the vertical direction, respectively, so that the cutting oil outlet and the pressurized air inlet of the oil supply tank are connected to the cutting oil inlet and the pressurized air outlet of the tool body, respectively.

Specifically, the drilling device may be arranged as follows. The tool body has a plug projecting from the tool body toward the fixing member. The cutting oil inlet and the pressurized air outlet are disposed in parallel with each other in the plug while being directed downward. The oil supply tank has a socket configured to engage with the plug of the tool body. The cutting oil outlet and the pressurized air inlet are disposed in parallel with each other in the socket while being directed upward. The oil supply tank is configured to be moved toward the tool body from the lower side of the tool body to engage the socket with the plug so that the cutting oil outlet and the pressurized air inlet of the oil supply tank are connected to the cutting oil inlet and the pressurized air outlet of the tool body, respectively.

In this drilling device, the oil supply tank is pressurized by pressurized air, whereby cutting oil is discharged from the oil supply tank and supplied to the tool. The connecting point of the oil supply line and that of the pressurized air supply line between the oil supply tank and the tool body are disposed in one place, whereby these lines are connected and disconnected at the same time. These lines are connected and disconnected by engagement and disengagement of the socket and the plug.

More specifically, the drilling device may be arranged as follows. The tubular slide unit includes a slit extending along the longitudinal direction of the tubular slide unit, a pair of fixing pieces extending radially outward so as to oppose each other across the slit, and a clamping unit having an operating member mounted on the pair of the fixing pieces and extending outward from one of the pair of fixing pieces. By operating the operating member, the fixing pieces are moved close to each other to fix the tubular slide unit to the column, and are moved away from each other to enable the tubular slide unit to slide along the column. The oil supply tank includes a tank body for storing cutting oil, which is disposed so as to oppose the column across the fixing pieces, and a tank attachment member fixed to the lateral side of the tank body corresponding to the other of the pair of fixing pieces. The tank attached member extends toward the tubular slide unit to be fixed to the tubular slide unit. The cutting oil outlet is formed in the tank attachment member.

The tool body may include a casing fixed to the upper end of the tubular slide unit, and an electric drill portion positioned on the side of the tubular slide unit diametrically opposite to the side on which the pair of fixing pieces are provided. The electric drill portion is vertically displaceable relative to the casing. The tubular slide unit may have a guide groove to guide the electric drill portion in the vertical direction.

Further, the tubular slide unit may include a guide groove forming portion extending on the diametrically opposite side of the tubular slide unit with respect to the pair of fixing pieces and forming the guide groove. The tank attachment member may be fixed to the lateral side of the guide groove forming portion.

In addition, the tank body may include a portion disposed so as to oppose the tubular slide unit across the pair of fixing pieces, and an extending portion extending between the other of the pair of fixing pieces and the tank attachment member from the portion toward the guide groove forming portion.

The present invention also provides a drilling device with an oil supply unit which includes an oil supply tank and a cutting oil supply passage for supplying cutting oil from the oil supply tank to a cutting tool. The drilling device also includes a pressurized air supply unit for supplying pressurized air into the oil supply tank so that the oil supply tank is pressurized by pressurized air to supply cutting oil from the oil supply tank to the cutting oil supply passage.

Generally, in this type of drilling device, a pump is provided in a cutting oil supply passage from the oil supply tank to the cutting tool, and the pump sucks cutting oil from the oil supply tank and supplies the cutting oil to the cutting tool. Meanwhile, in the drilling device according to the present invention, since the device is arranged as described above, cutting oil does not flow through the pump. Therefore, it is possible to avoid problems, such as that the pump is blocked with dirt contained in cutting oil, and that cutting oil freezes in the pump to break the pump in the winter season.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of a drilling device according to the present invention will now be described with reference to the accompanying drawings.

As shown in the figures, a drilling device10according to the present invention includes a fixing member12removably fixed to a workpiece W by means of an electromagnet, a column14(FIGS. 3 and 4) vertically extending from the fixing member12, a tubular slide unit16provided around the column so as to be slidable along the column, a tool body18connected onto the upper end portion of the tubular slide unit16, and an oil supply tank20provided between the tool body18and the fixing member12, and removably fixed to the tubular slide unit.

The tool body18has a casing22(FIG. 4) formed integrally with the upper end portion of the tubular slide unit16, and an electric drill portion24vertically displaceably disposed on the right side of the casing as viewed inFIG. 4. The electric drill portion24has an electric motor26, and is configured to rotationally drive an arbor38through an output shaft28of the electric motor and gears30,32,34, and36. The arbor38is configured such that a tubular cutter (not shown) can be attached to the lower end thereof coaxially with the arbor. A rack40(FIG. 4) is fixed to a housing39of the electric drill portion24. The rack is engaged with a pinion42rotatably attached to the casing22of the tool body. The electric drill portion24can be vertically moved by rotating the pinion42by means of a handle44shown inFIG. 2. As shown inFIG. 7, a guide groove48having a dovetail cross section is formed in the tubular slide unit16so as to extend vertically, and a dovetail-shaped convex portion50formed in the housing39of the electric drill portion is slidably engaged with the guide groove48. Thus, the electric drill portion is guided by means of the guide groove48.

As shown inFIGS. 4 and 7, the tubular slide unit16has a slit54extending from the lower end to the vicinity of the upper end thereof in the axial direction of the tubular slide unit16. The tubular slide unit also has a pair of fixing pieces56radially outward extending so as to oppose each other across the slit. A threadless hole57and a threaded hole58, which are aligned with each other, are formed in the respective fixing pieces. A clamping screw62rotated by a lever60is inserted into the threadless hole57and threadedly engaged with the threaded hole58. Thus, the fixing pieces56are moved close to and away from each other by rotating the lever60, whereby the tubular slide unit16(that is, the tool body18) is tightened against the column14to be fixed to the column and is allowed to slide along the column. InFIG. 4, reference numeral67denotes a connecting code connected to a power source; reference numeral68denotes a part of a switching unit for the electric motor26of the electric drill portion24and an electromagnet (not shown) of the fixing member12; reference numeral70denotes a power supply line to the electromagnet; and reference numeral71denotes a power supply line to the electric drill24, which is disposed along a grip73attached to the casing22of the tool body18.

FIG. 8is a sectional view of the drilling device10, with the oil supply tank20attached thereto, taken along line VII-VII inFIG. 4. As shown in the figure, the oil supply tank20has a tank body72provided so as to surround a part of the tubular slide unit16, and a tank attachment member74fixed to the side surface of the tank body by means of bolts77. As can be seen inFIG. 9showing the tank attachment member74in section taken along line IX-IX inFIG. 8, andFIG. 1, the tank attachment member74is generally quadrangular in shape and reinforcing ribs76are formed as a grid when the oil supply tank20is viewed from the front side, and bolts78are inserted into an extending portion72′ extending from the tank body72to fix the tank attachment member to the tubular slide unit16. A chip cover80for protecting the tank attachment member from chips generated in drilling operation is attached by means of screws82to the extending portion72′ disposed on the electric drill side of the tank attachment member74. As shown inFIGS. 9 and 10, the tank attachment member74is provided with an air passage94which extends vertically downward from a pressurized air inlet93opening upward at the vicinity of the upper edge of the tank attachment member and which is connected at the lower end thereof to an opening (not shown) formed in the side wall of the tank body72. The tank attachment member is also provided with a cutting oil passage96(similar to the air passage94) formed so as to parallel to the air passage94.

Correspondingly, a side wall outer surface22′ of the casing22of the tool body18is provided with a pressurized air supply passage100and a cutting oil supply passage102as shown inFIG. 9. The pressurized air supply passage100and the cutting oil supply passage102are communicated with the air passage94and the cutting oil passage96, respectively.

The pressurized air supply passage100extends from an air filter104, through two unimorph pumps (piezoelectric pumps)106, to a pressurized air outlet107having a duckbill check valve108. Meanwhile, the cutting oil supply passage102extends from a cutting oil inlet109communicated with an upper end outlet of the cutting oil passage96, i.e., a cutting oil outlet, through an on-off valve110and an oil dropper112, to a cutting oil discharge/supply port114communicated with a cutting oil receiving port formed in the outer surface of the housing39of the electric drill. The oil dropper112is a transparent tubular member, by which a flow of cutting oil can be checked from the outside. A cover23(FIG. 1) is removably attached to the side wall outer surface22′ to protect the pressurized air supply passage100and the cutting oil supply passage102.

FIG. 12is a sectional view of the unimorph pump106. A unimorph sheet122is stretched in a casing120. When an alternating voltage is applied to the unimorph sheet, the unimorph sheet vibrates, thereby generating an air flow through check valves124and126in the pressurized air supply passage100. This unimorph pump is disclosed, for example, in Japanese Unexamined Patent Application Publication No. 2007-132252, and therefore detailed descriptions thereof are omitted here.

Pressurized air received in the air passage94from the pressurized air supply passage100is supplied into the oil supply tank20to increase the internal pressure of the oil supply tank. Thus, cutting oil in the oil supply tank is supplied to the cutting oil supply passage102through a tube131, the distal end of which is immersed in cutting oil, and the cutting oil passage96.

In the illustrated embodiment, a plug130is provided at the lower end edge of the side wall of the casing22of the tool body18so as to downward project from the lower end edge. The air outlet107with the check valve108of the pressurized air supply passage100and the cutting oil inlet109of the cutting oil supply passage102are provided in the plug130so as to be parallel to each other.FIG. 11shows the plug130removed from the casing22. As clearly shown in the figure, the check valve108is a duckbill valve. Meanwhile, a socket132for receiving the plug130is formed on the upper end surface of the tank attachment member74. The socket has upper end portions of the air passage94and the cutting oil passage96. The plug130and the socket132are fitted to each other, whereby the air passage94and the cutting oil passage96are communicated with the pressurized air supply passage100and the cutting oil supply passage102, respectively.

In this drilling device, when the oil supply tank is replaced, the lever60is rotated in the clockwise direction from the position shown inFIG. 4so that the pair of fixing pieces56of the tubular slide unit16are moved away from each other to loosen the tubular slide unit16from the column14, and then the tubular slide unit16(that is, the tool body18) is lifted up. The chip cover80is removed from the tank attachment member74of the oil supply tank20to expose the bolts78fixing the tank attachment member74to the tubular slide unit16. Then, the bolts78are removed, and then the oil supply tank20is moved downward, whereby the socket132of the tank attachment member74is disengaged from the plug130of the casing22of the tool body18. Thus, the oil supply tank20is disconnected from the pressurized air supply passage100and the cutting oil supply passage102. After that, a replacement oil supply tank is set below the casing of the tool body and then lifted up, whereby the socket132and the plug130are fitted to each other. Thus, this oil supply tank20is communicated with the pressurized air supply passage100and the cutting oil supply passage102. After that, the oil supply tank20is fixed to the tubular slide unit16by means of the bolts78. Then, the tubular slide unit (that is, the tool body18) is slidably moved downward along the column14so that the attached oil supply tank20is clamped between the casing22of the tool body and the fixing member12. Then, the chip cover80is attached.