JPH0440152B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an origin setting method for determining a machining origin in an internal grinder type NC grinding machine.

Conventional technology NC grinding machine For example, in an internal grinder type, it is necessary to know the distance from the origin when making cuts in the positive direction and negative direction in the opposite direction in internal grinding, or in the positive direction and negative direction in external grinding. There is. For this reason, conventionally, for example, a dial gauge stand was attached to the spindle chuck, the measuring head of the dial gauge was brought into contact with the grinding wheel spindle, and the spindle was rotated to adjust the runout to zero, thereby aligning the center of the spindle with the center of the grinding wheel. However, it has the disadvantage that it requires manual operation, has poor work efficiency, and cannot be adapted to automation.

Purpose The present invention was made in view of the above, and it is an object of the present invention to provide a simplified setting method that does not require special setup and can be automated and unmanned.

Solution The present invention uses an NC grinding machine that grinds a workpiece once from two opposite directions using a grinding wheel that has been deflected, and the reading value of the detector of the cutting axis during the first grinding. , the diameter value of the workpiece, the reading value of the cutting axis detector during the second grinding, and the diameter value of the workpiece are respectively memorized, and based on these memorized values, C=1/4(D ₂ ~ D ₁ ) + 1/2 [f(x ₁ )
+ f(x ₂ )] to obtain the value C of the X-axis from the machine origin when the center of the grinding wheel axis and the center of the main axis coincide.

Embodiments Hereinafter, embodiments of the present invention will be described based on drawings illustrating an NC internal grinder. Bed 1 is 2 on top
Guide surfaces in the X-axis and Z-axis directions are provided in a T-shape. A cutting table 3 is slidably placed on the guide surface 2 in the X-axis direction (cutting direction), and a feed screw is positioned parallel to the guide surface 2 in the axial direction and screwed into the female thread of the cutting table. The amount of cutting is controlled by a motor 5 which is driven and rotated by a command from the NC. Then, the current position of the cutting table 3 is read by the NC based on a signal from the detector 7 attached to the motor 5. A headstock 10 rotatably supports a main shaft 8 in a direction perpendicular to the guide surface 2, and a dresser base 9 to which a dresser is attached are fixedly mounted on the cutting table 3.
The main shaft 8 has a chuck 11 at its tip that grips the workpiece.
are rotated via a belt 14 by a motor 13 provided on a headstock 10 with pulleys 12 fitted to their rear ends. Also, Dressesa is Dressesa Base 9
A dressing diamond 17 is fixed to the chuck side end of a piston rod 16 of a piston fitted in a hydraulic cylinder 15 having an axis in the X-axis direction, and when pressure oil is sent to the cylinder 15, the dressing is moved to the forward position. and the standby retracted position. On the other hand, a table 20 is slidably placed on a guide surface 6 in the Z-axis direction (grinding wheel movement direction) on the bed 1, and positioning control of a feed screw 21 is performed by a motor 22 driven by an NC command. The current position of the table 20 is then sent to the NC from a detector 23 attached to the motor 22. table 20
A grindstone shaft motor 27 is fixedly installed above the grindstone table 26 which rotatably supports a grindstone shaft 25 having a grindstone 24 at its tip, and a base. Grinding wheel 2
The rotation of the motor 27 is transmitted to the pulley 28 at the end of the shaft through the belt 29, and the rotation of the motor 27 is transmitted to the pulley 28 at the end of the shaft, causing the shaft to rotate at high speed.

Next, based on Figure 2, the value from the machine origin, which is the origin for machine-specific control determined by the NC of the X-axis when the center of the grinding wheel axis and the center of the main axis coincide, is C, the outer diameter of the grinding wheel used d The formula for calculating is explained.

In the internal laboratory, D ₁ = 2 [f (x ₁ ) - C] + d when the direction is positive as shown in Figure 2 B. D ₂ = 2 [C - f (x ₂ )]+d...(2) From formulas (1) and (2), C=1/4( _D2 - _D1 )+1/2[f( _x1 )+f( _x2 )
] ...(3) d = 1/2 (D ₁ + D ₂ ) - [f (x ₁ ) - f (x ₂ )] ... (4
) In the external laboratory, when the direction is positive from Figure 2 B, D' ₁ = 2 [C-f' (x ₁ )] - d' ...(5) When it is in the negative direction from Figure 2 C, D' ₂ = 2 [f' (x ₂ ) - C] - d' ... (6) From formulas (5) and (6), C = 1/4 (D' ₁ - D' ₂ ) + 1/2 [f' (x ₁ )+f′
(x ₂ )] ...(7) d′=1/2(D′ ₁ +D′ ₂ )+[f′(x ₂ )−f′(x ₁
)]...C and d or d' can be found by (8).

Next, based on the above equations (3) and (4), the procedure for setting the origin for internal grinding in this internal grinding machine will be explained with reference to FIGS. 1 and 3. The table 20 is moved in the Z-axis direction, the grindstone 24 is positioned relative to the diamond 17 of the dresser by NC, and pressure oil is sent to the rear chamber of the hydraulic cylinder 15 to position the diamond 17 in the forward position. Then, the cutting table 3 is moved forward by manual operation of a pulse handle or the like, and the grindstone 24 is dressed with the diamond 17. The value f(x ₀ ) of the X-axis detector 7 at this time is read by the decoder 31 and stored in the register 32 which is set by the dressing completion signal.

Next, pressure oil is sent to the front chamber of the hydraulic cylinder 15 to retreat the diamond 17 to the standby position, and the motor 5 is driven to move the cutting table 3 so that the grindstone 24 is inserted into the hole of the workpiece held by the chuck 11. The motor 22 is driven to advance and position the table 20 so that the table 20 is inserted. The feed screw 4 is rotated by the motor 5 to give cutting feed in the forward direction (FIG. 2B) to the cutting table 3 to slightly internally grind it. X-axis detector 7 at this time
The decoder 31 reads the value f(x ₁ ) of
(x ₁ ) is memorized. Then, the inner diameter of the workpiece is measured manually or automatically using a measuring device, and the value φD ₁ is inputted from the keyboard 30 to store the value D ₁ in the register 34 . Next, rotate the motor 5 in the reverse direction and rotate the feed screw 4.
Then feed the cutting table 3 in the opposite negative direction (Fig. 2 C) and move the workpiece to the grinding wheel 24 in the opposite position by 180 degrees.
Due to this, there is a slight internal grinding. The value f(x ₂ ) of the X-axis detector 7 at this time is read by the decoder 31, and the value f(x ₂ ) is stored in the register 35, which is set by the signal indicating the completion of negative cutting depth grinding. Then, the inner diameter of the workpiece is measured manually or automatically using a measuring device, and the value φD ₂ is inputted from the keyboard 30 and stored in the register 36. Next, from the keyboard 30, select circuit 3 for internal and external research.
8 instructs the arithmetic unit 37 that the calculation is in-house, and stores the stored value f(x ₁ ) in the register 33 and the register 3.
4 memory value _D1 Calculate equation (3) from the memory value f(x ₂ ) of the register 35 and the memory value D ₂ of the register 36, and store the computed value C in the register 40 set by the origin set command. . Subsequently, the arithmetic unit 37 calculates equation (4) using the stored value f(x ₁ ) of the register 33 , the stored value f(x ₂ ) of the register 35 , the stored value D ₁ of the register 34 , and the stored value D ₂ of the register 36 The calculated value d is stored in the register 41 set by the origin set command. When the values of C and d are determined, input the fact that it is an internal laboratory from the internal/external laboratory selection circuit 38, and select the correct cutting from the keyboard 30.
In the adder 42 which inputs the positive depth of cut from the negative depth of cut selection circuit 39, the value of the X-axis detector 7 during grinding is combined with the value f(x) read by the decoder 31 and the register 4.
From the stored value C of 0 and the stored value d of register 41
The calculation XA=2[f(x)-C]+d is performed. this value
The set value of the workpiece diameter is inputted with XA as the workpiece diameter value, and the value is sent to or displayed on a comparator 44 or the like that outputs a matching number. When the negative direction cutting is input to the adder 42, the adder outputs XA=
2[C-f(x)]+d is calculated. Also, the value f(x ₀ ) stored in register 32 is stored in register 40.
In the adder 45 which inputs _the stored value _C of
The value D ₀ is stored in the register 46 set by the origin setting command, and is stored as the distance of the diamond 17 of the dresser from the center of the spindle to correspond to a grindstone exchange or a distance change after dressing. Furthermore, in order to set the origin during external grinding using this grindstone, dress the grindstone 24 used for external grinding, and then set the cutting table 3 x so that the grindstone externally grinds the workpiece from the side opposite to the dresser. Slightly polish the surface by sending it in the positive direction of the axis (Fig. 2 B). At this time, the value f'(x ₁ ) of the x-axis detector 7 is read by the decoder 31 and the value f'(x ₁ ) is stored in the register 33.
Then, the value φD' ₁ , which is the measured outer diameter of the workpiece, is input from the keyboard 30, and the value D' ₁ is stored in the register 34. Next, the cutting table 3 is fed in the opposite negative direction (FIG. 2 C), and the workpiece is slightly ground with the grindstone 24 from the dresser side at a 180° opposite position. The value f'(x ₂ ) of the x-axis detector 7 at this time is read by the decoder 31 and the value f'(x ₂ ) is stored in the register 35 . Then, the measured value φD' ₂ of the outer diameter of the workpiece is inputted from the keyboard 30 and stored in the register 36. Next, inputting the fact that outer diameter grinding is to be performed from the internal grinding/outer grinding selection circuit 38 into the arithmetic unit 37 from the keyboard 30, the calculation of equation (7) is performed, and the value is stored in the register 40. Subsequently, the calculation of equation (8) is performed and the value d' is stored in the register 41. As with the internal grinding tool, the positive depth of cut and the negative depth of cut circuit 43 indicate that when the depth of cut is positive,
When X'A=2[C-f'(x)]-d' is a negative depth of cut, X'A=
2[f'(x)-C]-d' is calculated by the adder 42.

Effects As detailed above, the present invention makes one cut in each of the positive direction and negative direction of the inner diameter or outer diameter of the workpiece, and from the value of the X-axis detector and the measured value of the diameter of the workpiece, Calculate and find the value C from the machine origin of the X-axis and the grindstone diameter d when the center of the grinding wheel axis and the center of the main axis coincide, and based on these values, display or set the workpiece diameter from the value of the X-axis detector. Since the machine is machined to a value, no special setup is required, and the origin of the process can be easily determined, which has the advantage of shortening idle time during grinding work and improving work efficiency.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the NC internal grinder, Fig. 2 is a diagram showing the grinding procedure, and Fig. 3 is a block diagram of the calculation. 3... Cutting head, 7... Detector, 10... Headstock, 17... Diamond, 24... Grindstone.

Claims (1)

[Claims] 1. In an internal grinder-type grinding machine in which cutting feed is given by NC, cutting feed is given to the main spindle that grips the workpiece or the cutting axis of the grindstone to grind the workpiece for the first time. Or, store the first read value f(X ₁ ) or f'(X ₁ ) from the machine origin of the detector of the cutting axis at this time by external grinding, and also record the first diameter measured as the diameter of the workpiece. The value D ₁ or D′ ₁ is memorized, and then a cutting feed in the opposite direction is applied to the cutting axis, and a second internal grinding or external grinding is performed with the grinding wheel on the opposite side of the grinding point of the workpiece. The second reading value f(X ₂ ) or f'(X ₂ ) of the detector from the machine origin of the cutting axis at the time of levering is memorized, and the second diameter value obtained by measuring the diameter of the workpiece with this value is stored. memorize D ₂ or D′ ₂ ;
Based on the memorized first and second diameter values of the workpiece and first and second read values of the cutting axis, for internal grinding, C = (1/4) (D ₂ - D ₁ ) + (1/ 2) [f(X ₁ )+
f(X ₂ )] For external research, C = (1/4) (D' ₁ - D' ₂ ) + (1/2) [f' (X ₁
)+
f'(X ₂ )] to find the value C of the cutting axis from the machine origin when the center of the grinding wheel axis and the center of the spindle coincide. Setting method.