JPH05177490A - Work unit - Google Patents

Abstract

PURPOSE:To provide a work unit that strengthens a position holding force in a part to be driven by a direct drive motor and is hard to receive the effect of various external torques being imposed on the direct drive motor in working operations by installing a braking mechanism braking the direct drive motor. CONSTITUTION:A direct drive motor 11 is positioned and performs its rotational motion according to a sort of operations. A torque detecting means 60 detects the extent of output torque in the motor 11 from an exciting current given to a coil of this DD motor 11, thereby controlling the work motion of a finishing machine 80 according to the detected torque. In addition, a brake control means 90 has a braking mechanism 30 braked when the output torque of the DD motor 11 has exceeded the specified reference value, thereby locking a rotational position of the motor 11. For example, in a drilling unit, when cutting resistance in a drill grows larger and the extent of torque - the DD motor 11 outputs for holding a table 20 - has exceeded the specified reference value, it gets the braking mechanism 30 braked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a processing apparatus that performs a processing operation using a direct drive motor (hereinafter referred to as DD motor).

[0002]

2. Description of the Related Art Since a DD motor directly drives an object to be driven without passing through a speed reducer, good positioning accuracy can be obtained. Therefore, the DD motor is suitable for use in a processing device that requires highly accurate positioning operation. As a processing device using a DD motor, for example, Japanese Patent Application No. 3-30
There was a drilling machine described in the application specification of No. 0655 and a polishing machine described in the application specification of Japanese Patent Application No. 3-300656. The above-described drilling apparatus attaches a table on which a work is fixed to a rotor of a DD motor and performs drilling on the work while holding the position of the table by the holding torque of the DD motor. In addition, the above-described polishing apparatus places an object to be processed on a lap table, rotates the lap table with a DD motor, and rubs the object to be rubbed against the placement surface as the lap table rotates to perform polishing. Is to do.

However, in the drilling machine, when the cutting edge becomes abnormal and the cutting resistance increases, the force applied to the table increases due to the rotation of the drill, and the table cannot be held only by the holding torque of the DD motor. ..
Therefore, drilling is performed while the table vibrates, and the work becomes a defective product. For this reason, a means for holding the table with a stronger torque is needed. Further, in the polishing apparatus, when polishing is completed and the object to be processed is removed from the lap table, an abnormal torque may be applied to the DD motor that fixes the position of the lap table, which may adversely affect the motor. This also requires a means for holding the lap table with a stronger torque.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a braking mechanism is added to a DD motor used in a processing machine so that the DD motor is rotated by the DD motor. It is an object of the present invention to realize a processing device with enhanced position holding force.

[0005]

The present invention is a processing apparatus configured as follows. (1) In a processing device that performs a processing operation using a direct drive motor, the direct drive
A braking mechanism for braking the motor and a direct drive
Torque detecting means for detecting the output torque of the motor based on the exciting current supplied to the coil of the motor, and causing the braking mechanism to perform braking when the detected value of the torque detecting means exceeds a predetermined reference value. Brake control means, the braking mechanism is formed of a rigid body, an air chamber having an opening is formed, and a rigid body member fixed to one of a rotor and a stator of the direct drive motor. An elastic plate fixed to the rigid member by welding, closing the opening, and the welded portion surrounding the opening;
An air hole provided outside the region surrounded by the welded portion on the rigid member, an air passage communicating with the air chamber and the air hole through a thick portion of the rigid member, and a welded portion on the rigid member Mounting hole for the rigid member provided outside the area surrounded by,
An elastic plate fixed to the other of the rotor and the stator of the direct drive motor is deformed when compressed air is supplied to the air chamber, and a frictional force is applied between the rotor and the stator at the pressure contact portion. A processing apparatus comprising: a friction member for generating the friction member. (2) In the processing device, the table is directly attached to the rotor of the direct drive motor, and the position of the table is fixed by the holding torque generated by the direct drive motor. On the other hand, the processing apparatus according to (1), which is a drill processing apparatus that performs processing with a drill. (3) The processing device places an object to be processed on a lap table that is directly rotated by a direct drive motor, and rubs the object to be processed with a mounting surface of the lap table as the lap table rotates. The processing apparatus according to (1), which is a polishing apparatus that performs a polishing process on a portion to be rubbed together.

[0006]

According to the present invention, the output torque is detected from the exciting current supplied to the coil of the direct drive motor, and when the detected value exceeds the predetermined reference value, the braking mechanism is braked. Holds the rotation position of the direct drive motor by braking force. In the drilling machine,
When the cutting resistance of the drill increases and the torque output by the direct drive motor for holding the table exceeds a predetermined reference value, the braking mechanism is caused to perform braking. In the polishing machine, excessive torque is applied to the table while the table is stopped, and direct drive
When the holding torque of the motor exceeds a predetermined reference value, the braking mechanism is braked.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Figure 1
FIG. 1 is a configuration diagram showing an embodiment of the present invention. In FIG. 1, reference numeral 10 denotes an actuator, which includes a DD motor 11 and a rotation sensor 12. A drive target 20, such as a turntable, is attached to the rotor of the DD motor 11. The rotation sensor 12 detects the rotation of the DD motor 11, and is, for example, a magnetic resolver or an optical encoder. The DD motor 11 and the rotation sensor 12 are both outer rotor type, and rotors and stators are connected to each other. The basic configuration of the actuator 10 is similar to the actuator described in the specification of Japanese Patent Application No. 1-85614 filed by the present applicant. 30 is DD
It is a braking mechanism that mechanically brakes the motor 11. The specific configuration of the braking mechanism 30 will be described later. 40 is a DD based on the given command value and the detection signal of the rotation sensor 12.
A control unit that outputs a control signal that feedback-controls the rotation position, rotation speed, output torque, and the like of the motor 11, 50 is a drive circuit that supplies an exciting current to the coil of the DD motor 11 based on the control signal of the control unit 40, Reference numeral 60 is a torque detecting means for detecting the output torque of the DD motor 11 based on the exciting current supplied from the drive circuit 50. Reference numeral 70 is a processing control unit that controls the operation of the processing machine 80 according to the detection value of the torque detection unit 60, and 90 is a brake control unit that causes the braking mechanism 30 to perform braking according to the detection value of the torque detection unit 60.

In such a processing apparatus, the DD motor 11
Is positioned or rotated according to the type of work. At this time, the torque detection means 60 detects the output torque of the motor from the exciting current applied to the coil of the DD motor 11, and controls the processing operation of the processing machine 80 according to the detected torque. Further, the brake control means 90 causes the braking mechanism 30 to perform braking when the output torque of the DD motor 11 exceeds a predetermined reference value, and fixes the rotational position of the motor.

Here, a specific structure of the braking mechanism 30 will be described. FIG. 2 is a sectional view of the structure of the braking mechanism. This braking mechanism is the braking mechanism described in the specification of Japanese Patent Application No. 3-86284. In FIG. 2, 13 and 14 are the rotor and the stator of the actuator 10, respectively. The stator 14 is provided with a connecting portion 15 to which a compressed air supply source (not shown) is connected, and an air passage 16 connected to the connecting portion 15. 301 is a holding plate made of a rigid body, 3
Reference numeral 02 is an air chamber opened on both sides of the holding plate 301.
Reference numerals 303 and 304 denote elastically deformable clamp plates, for example, diaphragms made of sandvik. These clamp plates 303 and 304 are arranged on both sides of the pressing plate 301 and cover the opening of the air chamber 302.
305 and 306 are formed in a ring shape, and the air chamber 3
The clamp plate 3 is provided at a position on the outer peripheral side and a position on the inner peripheral side of 20.
It is a backing plate applied to 03,304. Patch plate 30
5, 306 are fixed to the holding plate 301 by welding together with the clamp plates 303 and 304. As a result, the welded portion becomes two circular orbits along the contact plates 305 and 306, and these circular orbits surround the air chamber. Holding plate 30
Similarly, the back plates 1 and 3 are provided with the contact plates 307 and 308. The welded portions are portions e to h in the figure. Thirty
Reference numeral 9 is a mounting hole that is formed inside a region surrounded by the welded portion of the holding plate 301 and through which the bolt 310 penetrates. By using the mounting holes 309 and the bolts 310, the holding plate 30
1 is fixed to the stator 14. 311 is an air hole formed inside the region surrounded by the welded portion on the holding plate 301 and connected to the air passage 16, and 312 is an air hole 311.
Is an air passage that communicates with the air chamber 302. Reference numeral 313 is a member connected to the rotor 13, and 314 is a member connected to the member 313. These members form a space in which the fixed side of the braking mechanism is housed. 315,316
Is a facing made of a material having a larger friction coefficient than the members 313 and 314. Facing 315,
316 is fixed to the member members 313 and 314. When air pressure is not applied to the air chamber 302, the facings 315 and 316 face the clamp plates 303 and 304 with a slight gap.

With such a braking mechanism, when compressed air is supplied to the air chamber 302, the clamp plates 303 and 304 are elastically deformed by receiving the internal pressure of the air chamber 302. Clamp plate 3
03, 304 and facings 315, 316 have a slight gap, so that the elastically deformed clamp plate 30
3, 304 are pressed against the facings 315, 316. As a result, the DD motor 11 is braked.

The present invention will be described in more detail with reference to specific examples. FIG. 3 is a configuration diagram of another embodiment of the present invention, and illustrates a case where the processing device is a drill processing device. 3, the same parts as those in FIG. 1 are designated by the same reference numerals. Hereinafter, the same applies in the drawings. In FIG. 3, 1
00 is a work to be processed, 101 is a work 100
The table 102 is fixed, 102 is a drill for machining the work 100, and 103 is a feeding means for causing the drill 102 to perform vertical feeding operation. Reference numeral 104 is a cutting resistance detecting means for detecting the cutting resistance of the drill from the output torque of the DD motor detected by the torque detecting means 60, and 105 is a feed when the cutting resistance detected by the cutting resistance detecting means 104 exceeds a predetermined reference value. It is a drill control means for sending a control signal to the means 103 to reduce the feed rate of the drill.

The operation of the processing apparatus thus configured will be described. When performing cutting with a drill, the DD motor 11
Fixes the rotation position and positions the work 100. At this time, the DD motor 11 generates a holding torque by the exciting current supplied to the coil. When the drill 102 performs a cutting process on the work 100, a rotational moment is applied to the table 101 by the component force of the force applied from the drill to the work. This rotational moment is, as shown in FIG. 4, a circumferential component force of the force applied from the drill to the work F,
When the radius of the position where the cutting is performed is r, it is Fr.
For such a rotation moment Fr, the DD motor 11
Generates a holding torque to hold the rotational position of the table 101. When the cutting resistance of the drilling increases, the rotation moment Fr applied to the table 101 increases, so the control unit 40 controls to increase the holding torque of the DD motor 11. The torque detection means 60 detects the holding torque generated by the DD motor 11 from the exciting current supplied from the drive circuit 50. Cutting resistance detecting means 104
Detects cutting resistance from the detected holding torque. When the detected cutting resistance exceeds a predetermined reference value, the drill control means 105 sends a control signal to the feed means 103 to slow down the feed speed of the drill because the force applied to the work is too large. In this way, the work side detects an abnormality during machining and controls the operation of the drill. Also, drill 10
The cutting resistance increases due to abnormalities on the blade edge of 2
When the holding torque output by the motor 11 exceeds the reference value,
The brake control means 90 causes the braking mechanism 30 to perform braking. This prevents the table 101 from vibrating due to the drill, and prevents the work 100 from becoming defective.

FIG. 5 is a block diagram of another embodiment of the present invention, illustrating a case where the processing device is a polishing device. In FIG. 5, 110 is a work to be polished, 111 is a lap table on which the work 110 is placed, and which polishes the work 110, 1
12 is a carrier for holding the work 110, 113 is a weight for pressing the work 110 against the lap table 111 by its own weight, 114 is a fixing member whose position is fixed, 115
Is a rotatable roller attached to the fixed member 114. The roller 115 is in contact with the carrier 112.
FIG. 6 is a view of the lap table 111 seen from above, and shows a contact state between the roller 115 and the carrier 112.
Reference numeral 116 denotes a polishing liquid supply unit that supplies the polishing liquid onto the lap table 111, and polishing liquid supply units 116 _{1 to} 116 _n having different abrasive grain sizes of the polishing liquid to be supplied are provided. Reference numeral 117 is a polishing resistance detecting means for obtaining a polishing resistance based on the torque detected by the torque detecting means 60. The polishing resistance R is calculated from the following equation. R = T ₁ −T ₀ (1) T ₁ : output torque of the DD motor detected by the torque detection means 60 T ₀ : minimum torque required to move the DD motor under no load condition. Has a torque dimension. The minimum torque T ₀ is a known value for the motor. Reference numeral 118 denotes a polishing liquid control means, which is a polishing resistance detection means 11
Based on the polishing resistance detected in 7, the polishing liquid supply means for supplying the polishing liquid is selected from 116 ₁ to 116 _n and the flow rate of the polishing liquid supplied is controlled.

The operation of the polishing apparatus thus configured will be described. As shown in FIG. 6, the work 110 is the carrier 11
It is fixed on the lap table 111 by a roller 2 and a roller 115 so that the lap table 111 can freely rotate and the position thereof does not move. D
When the lap table 111 is rotationally driven by the D motor 11, the work 110 rotates together with the carrier 112 due to the difference in peripheral speed depending on the radial position on the lap table 111. As a result, the work 110 is rubbed against the table surface of the lap table 111 and polishing is performed. FIG. 7 is a graph showing changes over time in the output torque T ₁ of the DD motor 11 during polishing. As shown in FIG. 7, the DD motor 11 increases the output torque T ₁ . Then, when the output torque T ₁ exceeds the static friction torque of the polishing apparatus, the lap table 111 starts rotating. At the initial stage, the polishing surface of the work 110 is rough and the contact area with the lap table 111 is small, so that the polishing resistance is small. As the polishing progresses, the contact area between the polishing surface of the work 110 and the lap table 111 increases, so that the polishing resistance increases. The polishing resistance becomes saturated when it increases to a certain value. This saturated stage is the stage where polishing is completed. In the saturation stage, the output torque T ₁ becomes substantially constant, and the minimum torque T ₀ has a constant value from the beginning, so that the polishing resistance R is saturated to a substantially constant value from the equation (1). The polishing resistance detecting means 117 sends a completion signal to the control unit 40 when the detected value of the polishing resistance is saturated, and terminates the polishing operation. The polishing liquid control unit 118 selects the polishing liquid supply units 116 _{1 to} 116 _n as the polishing resistance increases and reduces the abrasive grains of the polishing liquid supplied. The flow rate of the polishing liquid is also controlled. In this way, polishing is performed based on the polishing resistance, and rough polishing to finish polishing are performed by one polishing apparatus. When the polishing is completed, the DD motor 11 stops rotating and fixes the position of the lap table 111. When the work 110 and the weight 113 are removed from the lap table 111 in this state, an excessive torque may be applied to the DD motor 11. At this time, the brake control means 90 causes the braking mechanism 30 to perform braking, and fixes the lap table 111. As a result, the DD motor 11 is protected from excessive torque. Further, even when the polishing liquid runs out during polishing and the load on the DD motor increases, the braking mechanism 30 is operated to interrupt the polishing operation and protect the DD motor.

The processing device is not limited to the above-described drilling device or polishing device, and any device that performs a processing operation using a DD motor may be used.

[0016]

According to the present invention, the DD used in the processing machine
A braking mechanism was added to the motor to strengthen the position holding force of the part driven by the DD motor. As a result, it is possible to realize a processing device that is unlikely to be affected by various external torques applied to the DD motor during processing. For example, in the drilling device, since the position holding force of the table is strengthened, the vibration of the table is prevented even when the cutting resistance is increased, and the work can be prevented from becoming a defective product. Further, also in the polishing apparatus, since the position holding force of the table is strengthened, the DD motor can be protected from excessive torque applied to the table when the work is removed. Further, even when the polishing liquid runs out during the polishing operation, the polishing operation is interrupted and D
The D motor can be protected.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a braking mechanism used in the processing apparatus of FIG.

FIG. 3 is a configuration diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing a rotation moment generated by cutting.

FIG. 5 is a configuration diagram showing another embodiment of the present invention.

6 is a view of the lap table of the polishing apparatus of FIG. 5 as seen from above.

FIG. 7 is an operation explanatory view of the polishing apparatus of FIG.

[Explanation of symbols]

 11 DD motor 13 Rotor 14 Stator 20 Driven object 30 Braking mechanism 301 Holding plate 302 Air chamber 303, 304 Clamp plate 309 Mounting hole 311 Air hole 312 Air passage 315, 316 Facing 60 Torque detecting means 90 Brake control means 100, 110 Work 101 table 102 drill 111 lap table

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[Procedure amendment]

[Submission date] January 7, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 4]

[Figure 6]

[Figure 1]

[Fig. 2]

[Figure 3]

[Figure 7]

[Figure 5]

Claims (3)

[Claims] 1. A machining apparatus that performs a machining operation using a direct drive motor, wherein a braking mechanism for braking the direct drive motor and an exciting current supplied to a coil of the direct drive motor are used. And a brake control means for causing the braking mechanism to perform braking when the detected value of the torque detection means exceeds a predetermined reference value. Is a rigid body, and an air chamber having an opening is formed therein, and a rigid body member fixed to one of the rotor and the stator of the direct drive motor, and the opening fixed to the rigid body member by welding. An elastic plate that covers the opening and the welding portion surrounds the opening, and the air provided outside the region surrounded by the welding portion on the rigid member. A hole, an air passage for communicating the air chamber with the air hole through the thick portion of the rigid member, a mounting hole for the rigid member provided outside the region surrounded by the welded portion on the rigid member, An elastic plate that is fixed to the other of the rotor or stator of the direct drive motor is deformed when compressed air is supplied to the air chamber, and a frictional force is generated between the rotor and the stator at the pressure contact portion. And a friction member for causing the processing device to operate. 2. The processing apparatus is mounted on a table in a state where a table is directly attached to a rotor of a direct drive motor and the position of the table is fixed by a holding torque generated by the direct drive motor. The processing apparatus according to claim 1, wherein the processing apparatus is a drill processing apparatus that processes a workpiece with a drill. 3. The processing apparatus places an object to be processed on a lap table that is directly rotated by a direct drive motor, and the object to be processed is placed on a lap table mounting surface as the lap table rotates. The processing device according to claim 1, wherein the processing device is a polishing device that performs a polishing process at a portion to be rubbed together.