JPS5830610A - Feeding amount measuring device in digital manner for machine tool and the like - Google Patents

Abstract

PURPOSE:To perform accurate measurement and to make it possible to set an original point of movement at an arbitrary position, in the digital feeding amount measuring device for machine tool and the like, by using a microcomputer, and memorizing differences between the feeding mechanism and actual amount of movement in advance. CONSTITUTION:When a feeding shaft 4 is rotated, rotating signal is converted into pulses by an A-D converter 40 and counted by a counter A in the microcomputer 46. At the same time, the displacement of a moving member 8 is converted into accurate counting data B by a laser distance measuring device 42 which employes a laser oscillator 44 and a reflector 38. The entire length of the movement is divided at an arbitrary pitch based on the counted value A in the counter A, and the error in the measured value epsilon=A-B is computed at every pitch. Then the error epsilon is stored in an ROM50 in advance. When the feeding shaft is rotated, the accurate amount of the movement is computed and displayed from the amount of rotation A and said error epsilon. Furthermore, the display is reset at the arbitrary position, and the original position of the moving table is set at the arbitrary position.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a digital measuring device, and particularly to a digital measuring device that is used by being attached to a feed shaft of a machine tool or the like.

Digital measuring devices that digitally display the amount of rotation of a feed axis of a machine tool are known from US Pat. No. 4,117,520 and British Patent No. 1,499,504. The feed system of a machine tool generally includes a thread formed on the feed shaft, a nut screwed onto the thread, and a moving table connected to the nut.

Another common configuration of the feed system of a machine tool is to fix a gear to the feed shaft, engage a rack with the gear, and connect a movable table to the rack.

In the above configuration, when the feed shaft is rotated, the moving table moves in a linear direction. Therefore, by attaching the digital measuring device to the feed shaft, the rotational movement of the feed shaft is converted into a pulse signal, which is counted by a reversible counter, and the amount of movement of the moving table is displayed digitally. It turns out. However, as is well known, the feed screw forming the feed system of a machine tool has a screw precision error of Δe and a cumulative lead error of ΔE, as shown in FIG. Among these errors, the cumulative read error ΔE
can be mechanically corrected, but the thread accuracy error of Δ· cannot be mechanically corrected. Therefore, if you try to count and display the feed amount of the cutting table by the rotation of the feed screw using an A-D converter that converts the rotational movement of the feed screw into a pulse signal, the movement There is a defect that causes an error in the displayed value of the feed amount of the table.

Furthermore, when the feed amount of the movable table is counted and displayed by rotating the feed shaft to which the gears are connected, the same defects as described above occur due to pitch accuracy errors of the gears.Therefore, the main purpose of the present invention is to The output pulse of the converter is used as an address signal, and accurate movement measurement data corresponding to the address signal is input into the memory device of the micro combinator in advance, and the output pulse of the A-D converter is used as the micro combiator. The method is to input the data into a computer, call up the data corresponding to the pulse, and display the exact amount of movement of the moving platform on a display based on the data.

Another object of the present invention is to reset the display on the display to zero at any position on the movable base and to set the origin of the movable base at any position.

The structure of the present invention will be explained in detail below based on the embodiment shown in the attached drawings. In FIG. The supported nut member 06 is a nut member that is screwed into the threaded portion 4a of the feed shaft 4, and the nut member 6 is fixed to the moving member 8.

The threaded portion 4a and the nut member 6 constitute a feed system of the machine tool. 10 is a casing in which an A-D converter 12 is built. The casing 10 is removably fixed to the collar portion of the bearing member 2 by an adjustment screw 14. Reference numeral 16 denotes a plate member fixed to the casing 10, to which the digital display 1B is fixed, and the display portion of the display 18 is located directly below the window formed in the casing 10. Reference numeral 20 denotes a light receiving element composed of two phototransistors disposed in the casing 10, and a known fixed slit plate is arranged in front of the light receiving element. Reference numeral 22 denotes a light emitting element consisting of two light emitting diodes arranged on a plate member fixed to the casing 10, and the light emitting element 22 and the light receiving element 20 face each other with a predetermined distance therebetween. Reference numerals 24 and 26 are annular bushes that are fitted and fixed into holes in the casing 10, and the outer circumferential surface of the rotating body 28 is rotatably fitted onto the inner circumferential surface of the bushes. A key groove is formed along the axial direction on the inner circumferential surface of the rotating body 28, and a key 32 protruding from the outer circumferential surface of the collar 30 is fitted into the key groove. The feed shaft 4
It is fixed with screws. Reference numeral 34 denotes a known annular slit plate fixed to the flange of the rotating body 28, and the slit plate 34 is located between the light receiving element 20 and the light emitting element 22.

The above configuration constitutes the AD converter 12.

36 is a handle detachably fixed to one end of the feed shaft 4.

Fig. 4 shows a device for creating data to be written to a BP-ROM (read-only fixed memory) (see Fig. 6), which will be described later.
When rotated in forward and reverse rotation directions, it is guided by a guide device (not shown) and moves linearly in the left-right direction in the drawing. A reflector 68 is attached to the moving member 8. 4
0 is a digital measuring device including an A-D converter 12 attached to the bearing member of the feed shaft 4 (see FIG. 5, 2),
A rotating body 28 of the AD converter 12 is connected to the feed shaft 4. Reference numeral 42 denotes a known laser length measuring machine using a laser oscillator 44, and the output end of this and the output end of the pulse counting circuit section of the device 40 are input to an arithmetic circuit of a microcombi 46. 48 is a keyboard of the microcomputer, and 50 is a writing device for EP-ROM.

FIG. 6 shows an electronic circuit block diagram of the device.

In the figure, 12 is an A-D converter, and the above-mentioned light receiving element 2
0 is the output terminal. 52 is a Schmitt circuit, and 54 is an up/down discrimination circuit. The circuit 54 discriminates the direction component of the output pulse of the simulator circuit 52, that is, the phase shift of the pulse, and based on the result of this discrimination, the Schmitt circuit 52 It is determined whether the output pulse is supplied to the up-count line U or the down-count line D.

When the direction of the output pulse from the A-D converter 12 is in the positive direction, the pulse appears at the terminal e of the discrimination circuit 54, and when the direction of the output pulse from the A-D converter 12 is in the reverse direction, the pulse appears at the terminal e of the discrimination circuit 54. The discriminating circuit 54 is configured so that the signal appears at the terminal f of the discriminating circuit 54. 56 is a frequency divider circuit, 58 is a three-digit up/down counter, 60'' is a latch circuit, 62 is a CPU, that is, a central processing unit, and the A counter 64 of the CPU converts the pulses of the A-D converter 12 in the forward and reverse directions. In addition, the register 66 calculates A-Ers-R4, which will be described later.Furthermore, the CPU 98
The register 68 in the middle performs the calculation of A-E n, which will be described later, and the other register 70 calculates R4, which will be described later, based on a command from the origin setting switch 72 that gives an interrupt command to the CPU 62.
It is used to configure settings. 74 is a 7-digit latch circuit, 76
is a 7-segment decoder, 78 is a pulse oscillator, 80 is a 7-digit latch circuit, 82 is a dynamic/static conversion circuit, 84 is a memory read circuit, and 86 is an EP-ROM
In other words, 08 is a read-only storage device whose data can be erased.
8 is a memory interface circuit, 89 is a scan counter, 90 is a preset circuit, 92 is an all-reset circuit, and 94 is a reset switch, which are attached to the casing 10. The display 18 is composed of a plurality of 7-segment displays.
6 and counters 58 and 64 constitute a pulse counting circuit section.The above electronic circuit is housed in the casing 10 as an IC.

Next, the operation of the above embodiment will be explained.

First, the operation of writing accurate movement data into the EP-ROM 86 will be explained with reference to FIG. 4. First, the casing 10 is attached to the feed shaft 4 of the machine tool. To explain this work with reference to FIG. 5, first, remove the existing dial type display device from the feed shaft 4 of the machine tool, and then attach it to the force feed shaft 4 via a ball bearing on the feed shaft 4. Then, insert the keyway in the center of the rotating body 28 into the collar 50.
into the key 52.

Next, tighten the adjustment screw 14 to fix the casing/-u to the flange of the bearing member 2, and further fix the nozzle 36° to the feed shaft 4. The output end of the A counter 64 is connected to the input end A of a separately prepared micro combinator 46, and the output end of the laser length measuring machine 42 is connected to the input end B of the microcomputer 46. Next, after rotating the handle 56 to set the moving member 8 to the first origin, the reset switch 94 is pressed to reset all of the electronic circuit sections of the device 40 of the present invention to zero. As a result, R4, which will be described later, is set to zero. Furthermore, the counter at the output end of the laser length measuring device 42 is reset to zero. Next, when the nozzle 36 is manually rotated in the forward rotation direction and the feed shaft 4 is rotated,
The slit plate 34 rotates and the light receiving element 20 is
Out-of-phase pulse waves are generated.

The conopulse output is vertically shaped by the Schmitt circuit 52.Furthermore, this noclusal signal is converted into a pulse signal suitable for a kakuntal human signal through an up/down discrimination circuit 54, a frequency dividing circuit 56, and a counter 58. , A counter 64 and is counted by the counter 64. This count data A is input to the arithmetic circuit of the micro combinator 46. On the other hand, by rotating the handle 36, the movable member 8 moves, for example, in the direction of the arrow in FIG. It is input to the input terminal B of the arithmetic circuit of the combiator 46. The microcomputer 46 divides the total movement length of the moving member into arbitrary pitches based on the output signal of the pulse count circuit section, that is, the count signal of the A counter 640, and calculates the measurement value error A- of the A counter 64 for each pitch. Calculate B. That is, as shown in FIG. 2, the error of the count data A with respect to the count data B at the position where the movable member 8 has moved in the 1-arrow direction from the first origin based on the count value of the A counter 64 is El, 2. The error at the position is calculated as E2, and this data En is applied to the address signals 1, 2, 3-, 3-, etc., using the count data A as an address signal. Input it into the EP-ROM writing device 50 and write the Mukuro EP
- The above address signal A is written by the ROM writer 50.
and the corresponding En are written into the EP-ROM 86. Note that the micro combinator 46 is separate from the microcomputer shown in FIG. 6 whose main components include a CPU 62 and an IP-ROMa 6;
It can also be used in place of Yo46. Next, the output end of the pulse count circuit section is removed from the input end of the micro combinator 46.

Next, a case will be described in which the feed amount of the moving member 8 is displayed on the display 1B.

The moving member 8 is first set at the first origin. Next, when the handle 36 is rotated in the forward direction, the light receiving element 2 of the A-D converter 12
0 outputs a pulse signal with directionality, this signal is input to the up count terminal of the up/down counter 58 via the Shemitt circuit 52, up/down discrimination circuit 54, and frequency dividing circuit 56, and the count data A of this counter 58 is input to the A counter 64 of the CPU 62 via the two-touch circuit 60. This person counter 64 counts up and down the output of the counter 58 and outputs the contents as a BCD signal. The 9BCD signal output from the A counter 64 is supplied to a dynamic/static conversion circuit 82 via a 7-digit latch circuit 80, thereby converting it into a static signal. The output of this conversion circuit 82 becomes an address signal n for the IP-ROM. This address signal n is supplied to a memory read circuit 84, and the address output of the read circuit 84 is
6. The data En of the EP-ROMB6 specified by the address signal n is stored in the IP-ROM86.
The register 66 reads the contents A of the input counter 64 and the contents of the register 70 (Read). Based on the data EnK, A −E n −R4= T ・−”−”...(1)
Calculate.

In addition, the above R4 is the origin setting switch from the origin (not shown)
This is the A-En value when the R4ti register 68 is turned on, and is registered in the register 70 based on the contents of the R4ti register 68.

In this embodiment, as described above, all the circuits are reset by the reset switch 94 when the moving member 8 is positioned at the -th origin during measurement, so R4 is currently zero.

The output T of the register 66 of the CPU 62 is sent to the display 18 via a 7-digit latch circuit 74 and a 7-segment decoder 76.
is displayed digitally as a decimal number. The value displayed on the display 18 has the characteristics shown in FIG. That is, when the moving member 8 moves to the position corresponding to address 1, the count value of the A counter 64 of the CPU 62 at this time has an error of El, as shown in FIG.

Therefore, the output of the A counter 64 is directly displayed on the display 1B.
If this is displayed, the display 18 will display the feed data of the moving member 8 with an error of El.

However, in this device, the above (1) is stored in the register 66.
) is calculated, so that at the position of the moving member 8 corresponding to address 1, the display error on the display 18 is corrected to zero, and the correction value is displayed on the display 18.

Note that if the moving member 8 is stopped at an arbitrary position and the origin setting switch 72 is turned on at that position, the A-
The En value is set as the above R4 by software programmed in the CPU 98 in advance. Therefore, by turning on the origin setting switch, the display 18
can be set to zero at any position of the moving member 8. In addition, the rotation of the handle 36.

When the amount is in the plus area from the arbitrarily set origin,
The polarity indicator 18a of the display 18 shows the note +.If the handle 36 is reversely rotated within the positive range, the direction of the output of the Schmitt circuit 52 is determined by the direction determining circuit 54, and the output of the circuit 52 is The output pulse appears on the down count line D, and the pulse that appears on the skeleton line D is sent to the down count terminal of the counter 58 through the frequency dividing circuit 56, and the contents of the counter 58 are sequentially decreased.Press the origin setting switch 72. When the display 18 is set to zero and the feed shaft 4 is then rotated in the reverse direction, the polarity determination function of the CPU 62 is activated, a polarity signal is sent from the CPU 62 to the display 18, and a turtle is displayed on the polarity display section 18a of the display 18. -! is displayed.

Since the present invention is constructed as described above, the amount of movement of the moving member can be measured with the accuracy of a precision length measuring machine, and the precision length measuring machine can once store measurement data in the storage section of the -r microcomputer. Once done, you can remove it from the device and use it for other purposes. Furthermore, in this device, the origin can be set at any position of the moving member, which is extremely convenient.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram, FIG. It is an electronic circuit block diagram of the same. 2... Bearing member 4... Feed shaft 6... Nut member 8... Moving member 10... Casing 12... A-D converter 18... Digital display 20... Light receiving Element 22... Light emitting element 28
...Rotating body 36...Handle 38...Reflector 40...Digital measuring device 44...
Laser oscillator 42... Laser length measuring machine 46...
・Micro Combiator 48...Keyboard
50...Writer 52...Schmitt circuit
54... Up/down discrimination circuit 56... Branch circuit 58... 3-digit up/down counter 60.
...Latch circuit 62...CPU 64...A counter 66...Register 72...Origin setting switch Fig. 1 Fig. 2 (r') (2) Fig. 3

Claims (1)

[Claims] 1. A device that digitally measures the amount of movement of a moving member that moves due to the rotation of the feed shaft of a machine, which includes an A-D converter that converts the rotational movement of the feed shaft into a pulse signal, and l*
A pulse count circuit unit that counts output pulses of the A-D converter, and a count output A of the pulse count circuit unit.
The difference value En with respect to the precise measurement value B is stored using the count output A as an address signal, and when the output A of the pulse count circuit section is input when measuring the movement amount of the moving member, A -E n and outputs the calculated value, and at a desired position of the movable member, set a value R4 that is the same as the A-En value at that position, and - An origin setting switch connected to the micro combinator which subtracts the value R4 from the En calculation value and resets the calculation value of the microcomputer to zero at a desired position of the moving member. , and a display device that displays the calculation output of the micro combinator.