JP5410310B2 - Magnet chuck magnetic force adjusting device - Google Patents

Description

  The present invention relates to an apparatus for adjusting a magnetizing force of a permanent electromagnetic type or an electromagnetic type magnet chuck, and in particular, can appropriately adjust a magnetizing force in a low magnetizing region, and can appropriately attract a workpiece having low rigidity. The present invention relates to an apparatus for adjusting a magnetic force of a magnet chuck.

Conventionally, in a grinding machine, a work is attracted and held by a permanent electromagnetic magnet chuck provided on a table, and in this state, the work is ground by a rotating grindstone. (Patent Document 1 discloses a permanent electromagnetic magnet chuck)
When the workpiece is attracted and held on the magnet chuck, the attracting force can be changed according to the type of the workpiece. At this time, the rotary magnetic force adjustment switch for adjusting the magnetic force can adjust the magnetic force in, for example, 25 stages as shown on the horizontal axis of the graph of FIG. When this magnetizing force adjustment switch is operated, the magnetizing voltage (V) applied to the magnet chuck increases stepwise in direct proportion as shown by the magnetizing voltage adjusting pattern Ps in FIG. Yes.

  By the way, since the characteristics of the magnetizing force of the magnet chuck vary widely depending on the model of the magnet chuck, even if the magnetizing voltage rises in direct proportion as shown by one magnetizing voltage adjustment pattern Ps, for example, six magnet chucks. As shown in the characteristic curves F1 to F6 in FIG.

JP 2008-30144 A

  As shown in FIG. 7, the magnetizing forces of the six types of magnet chucks change as shown by the characteristic curves F1 to F6, respectively, but the first to seventh magnetizing force adjustment switches having a low magnetizing voltage (V). Between the scales, for example, the magnetizing force F1 (mT) hardly changes with the low magnetizing force. And in the 7th-9th scale of a magnetism adjustment switch, the magnetism tends to rise rapidly. For this reason, there were the following problems.

  When a workpiece having a small thickness and low rigidity is attracted by a magnet chuck, if the attracting force is excessively large, the workpiece is elastically deformed, and the flatness of the surface is lowered. In this state, the workpiece is ground with the rotating grindstone, and when the magnetic chuck is released after the workpiece is ground, the workpiece surface changes from a flat surface to a curved surface by elastic restoring force, and the flatness of the workpiece grinding surface is increased. descend.

  In order to solve the above problem, even if an attempt is made to set the coercive force in multiple stages so as not to cause elastic deformation of the workpiece in a region where the magnetic force of the magnet chuck is low, it is substantially within the range of the first to ninth scales. In addition, there is a problem that it is very difficult to properly adsorb the work by adjusting the magnetizing force in multiple stages because the magnetizing force can be adjusted only in three stages (seventh, eighth and ninth scales).

  In addition, as shown in the characteristic curves F1 to F6 of the six types of magnet chucks, the timings at which an effective magnetic force starts to act on the workpiece are different. For this reason, there is a problem that the amount of play of the magnetizing force adjustment switch varies depending on the type of magnet chuck, that is, the rotation angle of the adjusting switch until the magnetizing force starts to act effectively.

  The present invention provides an apparatus for adjusting the magnetizing force of a magnet chuck that solves the above-described problems of the prior art and can set an appropriate magnetizing force in accordance with the rigidity of the workpiece in the low magnetizing field region. There is to do.

  In order to solve the above-mentioned problems, the invention described in claim 1 is a method for adjusting a magnetizing force acting on a workpiece by adjusting a magnetizing voltage applied to a coil of a permanent electromagnetic type or an electromagnetic type magnet chuck. The gist of the invention is that it includes magnetic force adjusting means and pattern setting means for setting a magnetization voltage adjusting pattern corresponding to the model of the magnet chuck.

  According to a second aspect of the present invention, in the first aspect, the pattern setting unit stores a plurality of magnetization voltage adjustment patterns respectively corresponding to a plurality of types of the magnet chuck, and the magnetization voltage adjustment. The gist of the invention is that it comprises pattern selection means for selecting a magnetizing voltage adjustment pattern corresponding to the type of magnet chuck actually mounted from among the patterns.

  According to a third aspect of the present invention, in the second aspect, the storage medium stores a standard magnetization voltage adjustment pattern for adjusting the magnetization force by changing the magnetization voltage in direct proportion. The voltage change rate in the low magnetization voltage region of the selected magnetization voltage adjustment pattern is set to be smaller than the voltage change rate in the low magnetization voltage region in the magnetic voltage adjustment pattern. It is set so that the rate of change of the magnetizing force in the low magnetizing field based on the selected magnetizing voltage adjustment pattern is larger than the rate of change of the magnetizing force in the low magnetizing region based on the magnetizing voltage adjustment pattern. Is the gist.

(Function)
According to the first aspect of the present invention, an appropriate magnetization voltage adjustment pattern corresponding to the model of the magnet chuck is set by the pattern setting means. The magnetizing force of the magnet chuck based on the set magnetizing voltage adjustment pattern can optimize the rate of change in the magnetizing force in the low magnetizing force region. For this reason, adsorption | suction of a workpiece | work with low rigidity can be performed appropriately in steps or continuously in a low magnetizing magnetic force area | region.

  According to the second aspect of the present invention, a plurality of magnetization voltage adjustment patterns respectively corresponding to a plurality of types of magnet chucks are stored in advance in the storage medium. The pattern selection means selects a magnetizing voltage adjustment pattern corresponding to the type of magnet chuck actually mounted on a machine tool such as a grinding machine. The magnetizing force of the magnet chuck based on the selected magnetizing voltage adjustment pattern can optimize the rate of change in the magnetizing force in the low magnetizing force region. For this reason, adsorption | suction of a workpiece | work with low rigidity can be performed appropriately in steps or continuously in a low magnetizing magnetic force area | region.

  According to the present invention, it is possible to adjust the magnetic force to an appropriate magnetic force according to the low rigidity of the workpiece in the low magnetic force region of the magnet chuck.

The block circuit diagram which shows one Embodiment which actualized the magnetism adjusting device of the permanent electromagnetic magnet chuck of this invention. Explanatory drawing of the magnetism adjustment pattern of the several permanent electromagnetic magnet chuck from which the model memorize | stored in the storage medium differs. The longitudinal cross-sectional view of a permanent electromagnetic type magnet chuck. The graph which shows the relationship between the scale of a magnetizing-magnetism adjustment switch, and the magnetizing voltage of a some magnetizing voltage adjustment pattern. The graph which shows the relationship between the scale of a magnetizing magnetic force adjustment switch, and the magnetizing magnetic force of a specific magnetization voltage adjustment pattern. The flowchart for demonstrating a magnetic force adjustment operation | movement. The graph which shows the relationship between the conventional magnetism adjustment switch and the magnetism of several permanent electromagnetic magnet chucks.

Hereinafter, an embodiment in which the present invention is embodied as a permanent electromagnetic magnet chuck used in a grinding machine will be described with reference to FIGS.
First, the configuration of the permanent electromagnetic magnet chuck 11 will be described with reference to FIG. The chuck body 12 made of a magnetic material is formed in a bottomed square box shape, and a permanent electromagnet 13 is accommodated in the lower center inside thereof. The permanent electromagnet 13 includes a reversible permanent magnet 14 and a coil 15 wound around the outer peripheral surface of the permanent magnet 14. The permanent magnet 14 is a variable polarity permanent electromagnet whose polarity changes by changing the direction of the current flowing through the coil 15.

  A magnetic member 16 is disposed on the upper surface of the permanent magnet 14 so as to be positioned on the inner upper side of the chuck body 12, and a permanent member is provided between the magnetic member 16 and the upper side walls of the chuck body 12. A magnet 17 is accommodated. Around the permanent magnet 14, magnetic force lines 18 are always directed in a certain direction. Further, magnetic force lines 19 that are always directed in a certain direction are also generated around the pair of permanent magnets 17.

  Next, a description will be given of a magnetizing force adjusting device capable of adjusting the magnetizing force of the workpiece by adjusting the magnetizing voltage applied to the coil 15 of the permanent electromagnetic magnet chuck 11 (hereinafter simply referred to as the magnet chuck 11).

  A control unit 21 shown in FIG. 1 includes a central processing unit (CPU) 22 for performing arithmetic processing based on various data. The CPU 22 includes, for example, a control program for workpiece grinding work or various types of processing. A read-only memory (ROM) 23 is connected as a read-only storage medium that stores the data. Similarly, a read / write random access memory (RAM) 24 for storing various data is connected to the CPU 22. Connected to the CPU 22 is an input device 25 having a keyboard (not shown) or the like through which various data can be input and operation commands can be input. The input device 25 includes a magnetizing switch 26A that applies a voltage to the permanent electromagnet 13 of the magnet chuck 11 and outputs a magnetizing command for attracting the work to the upper surface of the chuck body 12 shown in FIG. Is provided. Further, the input device 25 is provided with a demagnetization switch 26B that outputs a demagnetization command for cutting off the voltage to the permanent electromagnet 13 and eliminating the adsorption of the workpiece. The input device 25 includes a rotary type magnetizing force adjustment switch 27 as a magnetizing force adjusting means for adjusting the magnetizing force of the workpiece by adjusting the magnetizing voltage applied to the coil 15 of the magnet chuck 11 in multiple stages. Is provided. The magnetism adjustment switch 27 outputs a signal for adjusting the magnetism to 25 levels by adjusting the pointer (Δ) of the operation knob 28 to any of the first to 25th scales of the scale plate 29 to the CPU 22. It has become.

  As shown in FIG. 1, a voltage regulator 31 is connected to the CPU 22, and a coil 15 of the magnet chuck 11 is connected to the voltage regulator 31. The voltage regulator 31 is supplied with a direct current from an alternating current power supply 32 through a power supply circuit 33 having a rectifying function.

Next, based on FIG.1 and FIG.2, the principal part structure of this embodiment is demonstrated.
As shown in FIG. 2, in the pattern storage area 36 provided in the ROM 23 or other storage medium, the coercive force is appropriately adjusted according to the first to ninth magnet chucks 11A to 11I of different models. Are stored. First to ninth magnetization voltage adjustment patterns P1 to P9 are stored. Each of the magnetization voltage adjustment patterns P1 to P9 is obtained by testing in advance according to the first to ninth magnet chucks 11A to 11I. As shown in FIG. 4, the voltage change rates δ1 to δ9 of the magnetization voltages P1v to P9v of the first to ninth magnetization voltage adjustment patterns P1 to P9 (see the gradients of the magnetization voltages P1v to P9v in FIG. 4) are as follows. Within the range of the first to seventeenth scales of the magnetic force adjustment switch 27, the voltage change rate δs of the magnetization voltage Psv of the standard magnetization voltage adjustment pattern Ps described in the background art (the gradient of the magnetization voltage Psv in FIG. 4). (See below). When the pointer of the operation knob 28 of the magnetization adjustment switch 27 exceeds the 17th scale, the magnetization voltages P1v to P9v of the adjustment patterns P1 to P9 are gradually converged. It is set to be.

  Here, based on FIG.4 and FIG.5, the 5th magnetization voltage adjustment pattern P5 is demonstrated as an example, comparing with the said standard magnetization voltage adjustment pattern Ps. As described in the background art, the magnetization force Fs of the standard magnetization voltage adjustment pattern Ps shown in FIG. 5 is the magnetization voltage change rate in the low magnetization voltage region (the first to ninth scales of the adjustment switch 27). Most of δs hardly changes and changes rapidly in the range of the seventh to ninth scales. Compared with the magnetization voltage change rate δs, the magnetization force F5 of the fifth magnetization voltage adjustment pattern P5 has a change rate δ5 (see the gradient of the magnetization force F5 in FIG. 5) in the low magnetization voltage region. It is set to increase in direct proportion.

  Also in the first to fourth adjustment patterns P1 to P4 and the sixth to ninth magnetization voltage adjustment patterns P6 to P9, although not shown, in the low magnetization voltage region of the magnetization F5 of the fifth magnetization voltage adjustment pattern P5. Similar to the rate of change δ5, the rates of change δ1 to δ4 and δ6 to δ9 are set so as to increase substantially in direct proportion to the rate of change δs.

  As shown in FIG. 1, the CPU 22 has a rotary type for selecting any one of the first to ninth magnetic force adjustment patterns P <b> 1 to P <b> 9 stored in the pattern storage area 36 of the ROM 23. A pattern selection switch 41 is connected. The pattern selection switch 41 includes, for example, an operation shaft 42 that is rotated by a tool such as a minus driver, and a scale plate 43 that displays numerals 1, 2, 3,... 9 indicating the first to ninth patterns. It has. Then, by directing the pointer (Δ) formed on the operation shaft 42 to one of the first, second,... 9 scales (for example, the fifth scale) of the scale plate 43, for example, the fifth wear The magnetic voltage adjustment pattern P5 can be selected.

  In this embodiment, pattern selection (setting) means for selecting the magnetization voltage adjustment patterns P1 to P9 is constituted by the CPU 22, the ROM 23, the pattern selection switch 41, and the like. As shown in FIG. 2, a standard magnetization voltage adjustment pattern Ps is also stored in advance in the pattern storage area 36 of the ROM 23. By operating the pattern selection switch 41, the standard magnetization voltage adjustment pattern Ps. Is selected, and the workpiece can be attracted based on the characteristic curve of the coercive force Fs shown in FIG.

Next, the adjustment operation of the coercive force of the magnet chuck 11 of the grinding machine configured as described above will be described.
The grinding machine is equipped with, for example, a fifth magnet chuck that is required from among the first to ninth magnet chucks 11A to 11I of different types. The operator determines the model of the fifth magnet chuck mounted on the grinding machine (step S1 in FIG. 5). Depending on the model of the magnet chuck, the operating shaft 42 of the pattern selection switch 41 is rotated by a screwdriver so that the pointer (Δ) is directed to the fifth scale of the scale plate 43. By this operation, the fifth magnetization voltage adjustment pattern P5 suitable for the fifth magnet chuck is selected (step S2 in FIG. 5).

  Thereafter, the operation knob 28 of the magnetizing force adjusting switch 27 is turned, the pointer (Δ) of the operating knob 28 is switched to, for example, the sixth scale, and the magnetizing force is adjusted (step S3 in FIG. 5). In this state, when the magnetizing switch 26A is turned on (step S4 in FIG. 5), a predetermined magnetizing voltage (25 volts as shown in the graph of FIG. 4) is applied to the coil 15 from the power source 32. . As a result, the work supported on the upper surface of the chuck body 12 shown in FIG. 3 is attracted by the predetermined magnetic force (10 mT) of the fifth magnet chuck (step S5 in FIG. 5).

  The workpiece held by the magnet chuck 11 is ground by a rotating grindstone (not shown). When the grinding of the workpiece is completed, the demagnetization switch 26B is turned ON, and the adsorption of the workpiece by the magnet chuck 11 is released.

According to the permanent electromagnetic magnet chuck of the above embodiment, the following effects can be obtained.
(1) In the above embodiment, the magnetizing force adjustment switch 27 is connected to the CPU 22 of the control device 21, and the pattern selection switch 41 is connected to the CPU 22. Further, the first to ninth magnetizing voltage adjustment patterns P1 to P9 corresponding to the first to ninth magnet chucks 11A to 11I of different models are stored in the pattern storage area 36 of the ROM 23. The pattern selection switch 41 selects one magnetization voltage adjustment pattern suitable for a specific type of magnet chuck mounted on the grinding machine. For this reason, a magnetization voltage adjustment pattern in which the rate of change δ of the magnetizing force F increases approximately in direct proportion in the low magnetizing region can be selected according to the model of the magnet chuck 11. Therefore, it is possible to adjust the appropriate magnetizing force necessary for workpiece adsorption in multiple stages in the magnetizing magnetic field region, properly performing adsorption according to the degree of low rigidity of the workpiece, and preventing deformation of the workpiece, The processing can be performed with high accuracy.

  (2) In the above embodiment, as shown by the curve of the magnetizing force F5 in FIG. 5, the scale of the magnetizing force adjustment switch 27 at which the magnetizing magnetic force starts to act effectively can be changed to the third scale with a small number. The play angle of the magnetic force adjustment switch 27 can be reduced. Further, even if the model of the permanent electromagnetic magnet chuck 11 is changed, the magnetization force curve in the low magnetization force region can be made substantially constant, so that variation in the play angle of the magnetization force adjustment switch 27 can be suppressed. .

(3) In the above embodiment, the magnetizing voltage adjustment pattern can be easily selected by rotating the operation shaft 42 of the pattern selection switch 41.
In addition, you may change the said embodiment as follows.

  Instead of the pattern selection means, pattern setting means for setting an appropriate magnetization voltage adjustment pattern corresponding to the model of the magnet chuck 11 may be provided. For example, the magnetizing voltage adjustment pattern corresponding to the model of the magnet chuck 11 is stored in an external storage medium separated from the control device 21. By operating the input device 25 and operating a pattern setting program stored in the CPU 22, the magnetizing voltage adjustment pattern is read from the storage medium and stored in the storage medium (ROM 23) in the control device 21 ( Setting).

The pattern selection switch 41 may be changed to a push button type switch.
The CPU 22 is provided with a touch panel type display device, and a window for displaying the model name of the magnet chuck 11 is provided on the screen of the display device. Moreover, the graph which shows the relationship between the magnetism adjustment switch 27 regarding the 1st-9th magnetization voltage adjustment patterns P1-P9, the magnetization voltage, and the relationship with a magnetization force is displayed. Then, by operating a pattern selection switch provided on the screen, one of the first to ninth magnetization voltage adjustment patterns P1 to P9 is selected according to the model of the magnet chuck 11 actually mounted on the grinding machine. You may enable it to select a pattern.

  As a storage medium for storing the first to ninth magnetization voltage adjustment patterns P1 to P9, the computer program is recorded in an external recording device (not shown) provided with a computer-readable recording medium in addition to the ROM 23. May be read from the external storage device as necessary.

The present invention may be embodied in an electromagnetic magnet chuck 11 instead of the permanent electromagnetic magnet chuck 11.
Next, technical ideas other than the invention described in the claims will be described together with effects.

  (A) The permanent magnet magnet according to any one of claims 1 to 3, wherein the magnetizing force adjusting means is a rotary type changeover switch capable of adjusting a magnetizing voltage in a stepwise manner. Chuck magnetic force adjusting device.

According to said structure, a change-over switch can be rotated and adjustment of a magnetizing force can be performed easily.
(B) The permanent magnet magnet chuck magnetic force adjusting device according to any one of claims 1 to 3, wherein the pattern selection means is a rotary pattern selection switch.

  According to said structure, the selection switch can be rotated and the selection operation | movement of a magnetization voltage adjustment pattern can be performed easily.

  F, F5, Fs: Magnetization force, δs, δ1-δ9: Voltage change rate, Ps: Standard magnetization voltage adjustment pattern, Psv, P1v-P9v: Magnetization voltage, P1-P9: Magnetization voltage adjustment pattern, 11 ... Magnet chuck, 15 ... coil.

Claims (3)

Magnetizing force adjusting means for adjusting the magnetizing force acting on the workpiece by adjusting the magnetizing voltage applied to the coil of the permanent electromagnetic type or electromagnetic type magnet chuck;
A magnet magnetism adjusting device for magnet chuck, comprising pattern setting means for setting a magnetizing voltage adjustment pattern corresponding to the model of the magnet chuck. The pattern setting means according to claim 1,
A storage medium for storing a plurality of magnetization voltage adjustment patterns respectively corresponding to a plurality of models of the magnet chuck;
A magnet chuck magnetic force adjusting device comprising pattern selecting means for selecting a magnetizing voltage adjusting pattern corresponding to a model of a magnet chuck actually mounted from among the magnetizing voltage adjusting patterns. 3. The storage medium according to claim 2, wherein a standard magnetization voltage adjustment pattern for adjusting a magnetization force by changing a magnetization voltage in direct proportion is stored in the storage medium, and a low magnetization voltage in the standard magnetization voltage adjustment pattern is stored. The voltage change rate in the low magnetization voltage region of the selected magnetization voltage adjustment pattern is set to be smaller than the voltage change rate in the region. By this setting, the low magnetization rate based on the standard magnetization voltage adjustment pattern is set. Magnetization force of a magnet chuck characterized in that the rate of change in the magnetization force in the low magnetization region is set to be larger based on the selected magnetization voltage adjustment pattern compared to the rate of change in magnetization in the magnetic region Adjustment device.

Images