JPH02184241A - Power source equipment for electrical circuit in rotary body - Google Patents

Abstract

PURPOSE:To feed power externally in contactless by interlinking the flux of a permanent magnet arranged concentrically to the rotary body around the rotary body with the coil in the rotary body and driving the internal electrical circuit with power produced in the coil. CONSTITUTION:A case 25 is arranged concentrically to a rotary body 11 and contacted with a brake shoe 34. The brake shoe 34 is fixed through a spring 35 to a supporting member 31. The case 25 is fixed with a pair of magnets 27N, 27S on the inner circumference thereof and engaged with the rotary body 11 through a bearing 26. Three coils 29a-29c are arranged on the circumferential section of the rotary body 11 and the power produced through interlinkage with the flux is rectified 36. A tool (not shown) arranged at the tip of the spindle 13 of the rotary body 11 contacts with a work to produce torque or thrust which is detected 16 and transmitted through a bridge circuit 17 and a transmission circuit 18 and an antenna 19, then it is received by a receiving antenna 21. By such arrangement, power can be fed reliably in contactless into the rotary body.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for supplying current and voltage necessary to drive electronic components installed inside various rotating bodies. The present invention relates to a power supply device for an electric circuit in a rotating body.

[Conventional technology]

In various machines and devices that have a rotating shaft and use this rotating shaft to rotate a predetermined object to accomplish a desired purpose, the torque, thrust (force in the direction of rotation), bending, vibration, etc. applied to the rotating shaft can be controlled. Detection is often essential for controlling these machines and devices. An example of such a machine or device is a tool holder for a rotary tool of a machine tool. In other words, when cutting a workpiece with a rotary tool such as a drill, tap, or end mill, if the rotary tool is broken, chipped, or worn, not only will it be impossible to perform the desired machining on the workpiece. If operation continues under such abnormal conditions, the workpiece may be damaged and the machine tool may be damaged. As a result, the losses caused by discarding the workpiece and the losses required for repairing the machine tool become extremely large.

In particular, in the case of a breakage accident of a tool, it becomes difficult to deal with the accident because the tool bites into the workpiece, and even if the workpiece itself is not damaged, it often becomes necessary to discard it.

In recent years, in factory automation (FA), unmanned operation of numerically controlled machine tools has been planned. It is essential to take appropriate measures.

However, it is impossible to prevent the above-mentioned loss because it is too late to detect the abnormal condition itself. Therefore, it is necessary to predict the occurrence of the abnormal condition in advance and make the rotating tool avoid the occurrence of the abnormal condition. That is, it is necessary to perform operations such as retracting, stopping, and reducing the rotational speed of the rotary tool.

A device that satisfies these requirements is disclosed, for example, in Japanese Patent Application Laid-open No. 1983-
This is disclosed in Publication No. 166948 and the like. This will be explained using a diagram.

Figure 4 is a cross-sectional view of a conventional tool holder for rotating tools.
In the figure, 10 indicates a tool holder of a rotary tool, 11 is a cylindrical portion thereof, and 12 is a shank portion thereof. Shank part 12
is installed in the spindle hole of the machine tool, and thereby the cylindrical part 11
is rotated.

13 is the main shaft provided in the cylindrical part 11, 14 is the main shaft 13
This is a chuck for mounting a rotary tool that is fixed to the tip of the rotary tool.

15a and 15b are support members that support the main shaft 13 within the cylindrical portion 11, and 16 is a detection section fixed to the main shaft 13. 1
7 is a detection circuit that converts the thrust and torque detected by the detection unit 16 into electrical signals corresponding thereto; 18 is a transmission circuit that transmits the output signal of the detection circuit 17 to the outside; 19
2 is a transmitting antenna, and 20 is an antenna support fixed at an appropriate location outside the tool holder 10.

21 is a receiving antenna supported by the antenna support section 20.

In the above configuration, the support members 15a and I5b are connected to the main shaft 13.
It has a flexible structure in the axial and rotational directions, which creates a thrust that is applied to the rotating tool.

Torque is not transmitted to the cylindrical portion 11 but is transmitted to the detection portion 16 via the main shaft 13. On the other hand, the structure has a sufficiently large rigidity in the radial direction, so that the main shaft 13 is supported by the cylinder 11 without horizontal vibration. Further, the detecting section 16 is constructed to generate a strain corresponding to the thrust and torque transmitted through the main shaft 13, and the magnitude of the strain is detected using a strain gauge.

An overview of thrust and torque detection operations using such a tool holder 10 will be explained using an example of drilling with a drill. Drilling is performed by mounting a drill on the tool mounting chuck 14 and rotating the cylindrical portion 11 with a machine tool. During cutting with a drill, thrust is applied to the main shaft 13 (ie, the drill) in the axial direction and torque is applied in the rotational direction. As described above, the main shaft 13 is supported by the supporting members 15a and 15b so that it can be freely displaced only in the axial direction and only around the axis. Therefore, the thrust and torque applied to the main shaft 13 are transmitted to the detection section 16 without any problem even if the cylindrical section 11 is rotating. Then, the strain gauge provided in the detection section 16 is deformed in accordance with these thrusts and torques, and its resistance value is changed. These changes in resistance value are taken out as an output by a detection circuit 17 consisting of an appropriate configuration such as a bridge circuit, an amplifier circuit, etc., and this output is sent to a transmitting circuit 18,
It is transmitted to the outside of the tool holder via the transmitting antenna 19.

The receiving antenna 5 receives this signal, amplifies the received signal as a thrust signal and a torque signal, and then outputs the signal to a control device (not shown).

The cutting process of the drill is controlled while constantly monitoring these thrust signals and torque signals.

[Problem to be solved by the invention]

The detection unit 16, detection circuit 17, and transmission circuit 18 built into the tool holder 10 require a constant voltage source for the bridge circuit, and a power source for driving the amplifier circuit and the transmission circuit.

Normally, when power is supplied to the rotating tool holder 10 as described above, a means is employed in which a battery is built into the tool holder 10, or a means is employed in which power is supplied from an external source via a slip ring.

However, means having a built-in battery requires a long-life battery, and there are problems in that it is necessary to monitor the voltage of the battery. In addition, methods that use slip rings not only generate noise and reduce detection accuracy, but also use in an environment where cutting oil is scattered, and the cutting oil adheres to the slip ring, making the power supply unstable. There was a problem. These spacings are a problem not only in tool holders, but also in other rotating bodies that have internal electrical circuits.

The purpose of the present invention is to solve the problems in the above-mentioned prior art,
An object of the present invention is to provide a power supply device for an electric circuit inside a rotating body, which can reliably supply power.

[0 Means for Solving the Problems] In order to achieve the above object, the present invention provides a rotating body having an electric circuit inside thereof, which is arranged near the outer periphery of the rotating body concentrically with its rotation axis. A power supply device is configured by a permanent magnet, a coil provided on the rotating body and crossing the magnetic field of the permanent magnet when the rotating body rotates, and an electricity supply means for supplying electricity generated in the coil to the electric circuit. It is characterized by what it did.

[For production]

When the rotating body rotates, the coil provided on the rotating body crosses the magnetic field of the permanent magnet, and electricity is generated in the coil. Electricity generated in the coil is supplied to an electrical circuit within the rotating body by a power supply means.

〔Example〕

Hereinafter, the present invention will be explained based on illustrated embodiments.

FIG. 1 is a sectional view of a power supply device according to an embodiment of the present invention, and FIG.
The figure is Figure 0, which is a sectional view taken along line U-U shown in Figure 1.
Components that are the same as those shown in FIG. 4 are given the same reference numerals, and their explanation will be omitted. A case 25 is supported on the outer peripheral surface of the cylindrical portion 11 of the tool holder via a bearing 2b. 27N, 2
Permanent magnets 7S are fixed to face each other inside the case 25, and the N pole of the permanent magnet 27N faces the cylindrical portion 11, and the S pole of the permanent magnet 27S faces the cylindrical portion 11. 28a, 2
Cores 8b and 28c are fixed to the cylindrical portion 11 along its circumference, and are spaced apart from each other by 120 degrees. 29a, 29b, 29c are each core 28a, 28
It is a coil wound around b, 28c. Permanent magnets 27N, 27S, cores 28a to 28c and coil 2
9a to 29c constitute a generator.

30 indicates the operation@thief body. Reference numeral 31 denotes a support member fixed to a predetermined location of the machine tool body 30.

The receiving antenna 21 is supported by the tip of a protrusion of a support member 31 formed at a position opposite to the transmitting antenna 19. A rod holding case 32 is fixed to the support member 31 and is positioned opposite to the case 25. 3
3 is a rod that is vertically movably held in a rod holding case 32, and 34 is a brake shoe 35 fixed to the end of the rod 33, which is a spring that presses the rod 33 downward.

Reference numeral 36 indicates a power supply circuit to which each of the coils 29a to 29c is connected. A specific example of this power supply circuit 36 is shown in FIG.

FIG. 3 is a block diagram of a specific example of the power supply circuit shown in FIGS. 1 and 2, in which the same parts as those shown in FIGS. 1.2.4 are given the same reference numerals. The power supply circuit 36 includes a rectifier circuit 36 that rectifies the current generated in each coil 29a to 29c.
a, a limiter 36b1 that limits the magnitude of the DC current and voltage obtained by this rectifier circuit 36a, and three regulators 36C0 to 36C1 that adjust the voltage. The detection circuit 17 includes a bridge circuit 17a and a bridge circuit 17 that detect changes in the resistance value of the strain gauge described above.
It is composed of an amplifier circuit 17b that amplifies the detection output of a. The regulator 36C3 is connected to the bridge circuit 17a, the regulator 36ct is connected to the amplifier circuit 17b, and the regulator 36C1 is connected to the transmission circuit 18, and the voltages of the respective circuits are adjusted to appropriate voltages.

Next, the operation of this embodiment will be explained. When attaching the tool holder to the machine tool body 30, the rod 33 is attached to the spring 35.
The case 25 is pushed upward against the spring force of the rod 3.
3 and the brake shoe 34 so as not to collide with each other. After the tool holder is attached, when the push-up is released, the brake shoe 34 is pressed against the case 25 by the spring force of the spring 35.

As a result, the case 25 and the permanent magnet 27N.

27S is fixed at the position shown. When the tool holder rotates in this state, each coil 29a to 29c is stopped by the permanent magnet 27N, 27, which is stopped by the brake shoe 34.
This crosses the static magnetic field of S, thereby generating alternating currents whose phases are shifted by 120 degrees in each of the coils 29a to 29C. This alternating current is rectified into direct current by the rectifier circuit 36a, and after suppressing excessive voltage and current by the limiter 36b, each regulator 3601 to 36C1
is supplied to These regulators 36C4 to 36C1
, respectively connect the supplied DC to the bridge circuit 17a.

The voltage is adjusted to a predetermined voltage necessary for the amplifier circuit 17b and the transmitter circuit 18.

Here, when machining is started and the drill attached to the tool holder comes into contact with the workpiece and drilling of the workpiece is started, the thrust and torque generated by this are applied to the main shaft 13.
The thrust and torque are transmitted to the detection section F, and strain occurs in the strain section of the detection section 17 in accordance with the transmitted thrust and torque. This strain causes strain in the strain gauge, and the amount of strain is detected by the bridge circuit 17a. The detected strain amount, that is, thrust and torque is transmitted to the bridge circuit 17a.
The signal is output as an electrical signal from the amplifier circuit 17b, and is output from the transmitting antenna 19 by the transmitting circuit 17b. This transmission signal is received by the receiving antenna 21,
It is input to a control device (not shown). This control device constantly compares the input thrust and torque signals with predetermined values, and as a result of the comparison, performs necessary actions such as activating an alarm device or stopping machine tool operation, if necessary. The process will be executed.

As described above, in this embodiment, a coil is arranged in the cylindrical part of the tool holder, a permanent magnet is supported on the outer periphery of the cylindrical part via a bearing, and this permanent magnet is fixed by a brake shoe.
Since electricity is generated in the coil by the rotation of the tool holder, power can be reliably supplied to the detection circuit and transmission circuit without using batteries or slip rings.

In addition, in the description of the above embodiment, a tool holder of a machine tool was exemplified as a rotating body, but the present invention is not limited to this and can be applied to any other rotating body.

Further, although the explanation has been given by exemplifying the means of fixing the permanent magnet using brake shoes, any means can be used as long as it can fix the permanent magnet in a predetermined positional relationship with respect to the rotating body. Can be done.

(Effects of the Invention) As described above, in the present invention, a permanent magnet is arranged on the outer periphery of the rotating body, a coil is provided on the rotating body, and electricity is generated in the coil by the rotation of the rotating body.
Electric power can be reliably supplied to the electrical circuit inside the rotating body without using batteries or slip rings.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a power supply device according to an embodiment of the present invention, and FIG.
The figure is a sectional view taken along the line n-n shown in Figure 1, and Figure 3 is a cross-sectional view taken along the line nn shown in Figure 1.
FIG. 4 is a block diagram of the power supply circuit shown in the figure, and FIG. 4 is a sectional view of a conventional tool holder for a rotary tool. 11・・・・・・Rotating body, 13・・・・・・・・・
・Main shaft, 16...Detection section, 17...
...Detection circuit, 18...Transmission circuit, 25...Case, 26...
...Bearing, 27N, 27S...Permanent magnet, 28a-28c...Core, 29a-2
9c・・・・・・・・・Coil, 31・・・・・・・・・
・Supporting member, 33...Rod, 34...
・・・・・・Brake shoe, 35・・・・・・・・・
・Spring, 36...Power circuit. Figure 1!5 T/

Claims (3)

[Claims] (1) In a rotating body equipped with an electric circuit inside,
A permanent magnet is arranged on the outer periphery of the rotating body concentrically with the rotating shaft, and a coil is installed on the rotating body and crosses the magnetic field of the permanent magnet when the rotating body rotates. A power supply device for an electric circuit in a rotating body, characterized in that it is provided with electricity supply means for supplying electricity to the electric circuit. (2) In claim (1), the permanent magnet is supported by the rotating body via a bearing and is prevented from moving in the rotational direction of the rotating body by a braking means. A power supply device for the electrical circuit inside the rotating body. (3) A power supply device for an electric circuit in a rotating body according to claim (1), wherein the electricity supply means includes a rectifier circuit, a current limiting circuit, and a constant voltage circuit.