JPS60114449A - Centering arbor for machine tool - Google Patents

Abstract

PURPOSE:To prevent breakdown even for strong pressing due to reverse motion by splitting an arbor into holder section to be fixed on spindle and measuring section contactable with a work then coupling the measuring section separatably with the holding section through a magnet. CONSTITUTION:When feeding a work 3 in the direction departing from the measuring section 8 of centering arbor 6 by means of a table 4 after measuring the referential working point, said arbor 6 will never breakdown even if feeding in reverse direction because the measuring section 8 is coupled separatably with the holder section 7 through adsorbing force of magnet 13 to be dropped from the holder section 7 upon application of lateral force onto the measuring section 8. The referential point can be measured continuously through re-coupling of measuring section 8 to the holder section 7 where re-coupling can be quickened because the measuring section 8 is coupled through chain 18 to the holder section 7.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a centering arbor for measuring a reference point for machining a workpiece in a machine tool.

[Technical background of the invention]

For example, in a machining center, a reference point for machining a workpiece is measured for each of the X, Y, and Z axes, and a machining position is determined from the reference point. Measurement of this reference point is carried out by attaching a centering arbor to the spindle and manually moving the table with the workpiece attached to it so that the workpiece comes into contact with the centering arbor. The contact point of the workpiece to the centering arbor is used as the reference point for machining.

(Problems in the background art) However, after measuring the reference point, the table is sometimes mistakenly sent in the opposite direction when the workpiece should be sent in the direction away from the centering arbor. If this occurs, the conventional centering arbor is a round bar-shaped integral piece, and therefore, it is strongly pressed against the workpiece and breaks.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its object is to provide a centering arbor for a machine tool that is free from breakage even when strongly pressed against a workpiece.

[Summary of the invention]

The present invention has a configuration in which the holder is divided into a part that is attached to the main shaft of a machine tool and a measuring part that comes into contact with the workpiece, and the measuring part is separably connected to a part of the boulder via a magnet. It is something.

(Embodiment of the Invention) An embodiment of the present invention will be described below with reference to the drawings.First, in FIG. It is equipped with a table 4 to be attached, and the table 4 can be moved manually by operating a handle. Reference numeral 5 denotes a chuck detachably attached to the main shaft 2, which has a chuck according to the present invention. A centering arbor 6 is attached to the centering arbor 6. As shown in FIG. The part 7 is composed of a cylindrical main part 10 with a cap 9 screwed onto one end, and a connecting cylinder 12 fitted to the main part 10 via an electrically insulating cylinder 11.The lower end of the connecting cylinder 12 has a large diameter. A magnet 13 is embedded and fixed in the portion 12a, and a circular fitting recess 14 is formed in the lower surface of the large diameter portion 12a.
A lamp 15 and a battery 16 are inserted into the three-piece connecting tube 12, and a plurality of holes 17 are formed in the connecting tube 12 so that the lamp 15 can be seen from the outside. On the other hand, the measurement part 8 has a round bar shape, and has a contact part 8a formed at its lower end, and a large diameter part 8b fitted into the fitting recess 14 of the holder part 7 at its upper end. The measuring section 8 is connected to the connecting tube 12 of the holder part 7 by a chain 18.

The main part 10, the connecting cylinder 12, and the measuring part 8 of the holder part 7 are made of alloy steel or the like with excellent strength and wear resistance, and the bottom surface (inner upper surface) and inner periphery of the fitting recess 14 are made of alloy steel with excellent strength and wear resistance. The surface and the upper surface and outer circumferential surface of the large diameter portion 8b of the measuring part 8 are formed with high precision, so that when the large diameter part 8b is fitted into the fitting recess 14, the measuring part 8 and the holder part 7 will be misaligned. I try not to let that happen.

Next, the operation of the above configuration will be explained. First, centering arbor 6
To connect the measuring section 8 to the holder part 7, the large diameter part 8b of the measuring part 8 is fitted into the fitting recess 14 of the holder part 7. Then, the measurement part 8 made of steel, which is a magnetic material, is attracted to the magnet 13, and the measurement part 8 is separably coupled to the holder part 7 by the attraction force. Next, in order to measure the reference point for machining the workpiece 3, the chuck 5 to which the centering arbor 6 is attached is attached to the main shaft 2, and the table 4 is manually moved back and forth, left and right, and up and down. , for example - side of the workpiece 3.

The other side surface and the upper surface are brought into contact with the outer peripheral surface and lower end surface of the contactor 8a of the centering arbor 6, and the contact points are X and Y, respectively.
, and Z as a reference point for each axis. In this case, when the workpiece 3 comes into contact with the contact portion 8a, the main portion 10 of the holder portion 7 is located between the lamp 15 and the battery 16. Chuck 5.
Main body of machining center 1. Table 4. Workpiece 3
．． Electricity is established through the connecting cylinder 12 of the measuring part 8 and the holder part 7, and the lamp 15 is lit, so it can be determined whether or not the workpiece 3 has contacted the contact part 8a.

After measuring the reference point for machining, the table 4 is sent in the direction in which the workpiece 3 moves away from the measuring part 8-5- of the centering arbor 6. Sometimes I send it to. Then, since the measuring part 8 of the centering arbor 6 is pressed by the workpiece 3,
Particularly when feeding in the horizontal direction, there is a risk that the centering arbor 6 will receive a lateral force and break. However, in the present invention, the measurement unit 8 is attached to the holder part 7 with the magnet 13.
Since the configuration is such that they are separably connected by the adsorption force of the measuring section 8, when a lateral force is applied to the measuring section 8, the measuring section 8 separates from the holder part 7 and falls, so it is unlikely that the centering arbor 6 will actually break. do not have. If the measuring part 8 falls off from the holder part 7, the measurement of the reference point can be continued by reconnecting the measuring part 8 to the holder part 7 as described above. In this case, since the measurement part 8 is connected to the holder part 7 by the pin 18, it will not roll away or be lost, and can be quickly reconnected.

In the above embodiment, the reference point was measured by bringing the centering arbor 6 into contact with the outer surface of the workpiece. The contact site can be selected as appropriate. Moreover, it can be widely applied not only to machining centers but also as a centering arbor for machine tools such as boring machines and milling machines.

〔Effect of the invention〕

As explained below, the present invention is divided into a part of the holder attached to the main shaft of a machine tool and a measuring part that contacts the workpiece, and the measuring part can be separated from the part of the holder by the attraction force of a magnet. Since the structure is such that the measuring part is connected to the workpiece, if a large force is applied to the measuring part by moving it in the opposite direction when it should be moved away from the workpiece after contacting the workpiece, the measuring part There is no risk of breakage just by falling off a part of the holder, and it has excellent effects such as being able to be used semi-permanently for a long time.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a side view schematically showing a machining center, Fig. 2 is a vertical side view of a centering arbor, and Fig. 3 shows a core with the lamp removed. FIG. 3 is a partially enlarged cross-sectional view of the output arbor. In the diagram, 1 is the main body of the machining center (machine tool), 2
3 is a main shaft, 3 is a workpiece, 6 is a centering arbor, 7 is a part of a holder, and 8 is a measuring part. Applicant Tokyo Shibaura Electric Co., Ltd.-8- Part II! 1 Second Seal

Claims (1)

[Claims] 1.In a device that is attached to the main spindle of a machine tool and measures the reference point of machining by contacting the workpiece, the holder is divided into a part of the holder attached to the main spindle and a measurement part that comes into contact with the workpiece. A centering arbor for a machine tool, characterized in that a part is separably connected to a part of a holder by the attraction force of a magnet.