JPS6258871B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an index confirmation device for a numerically controlled grinding machine, which is used when sequentially indexing and machining parts of a workpiece to machining positions.

When grinding each step of a multi-step workpiece in the axial direction using a numerically controlled grinding machine, by moving the table on which the workpiece is installed, each step of the workpiece can be machined in sequence to the processing position. It is now possible to index and process it.

However, in order to shorten the machining cycle time, grinding machines generally use a large rapid feed rate and start grinding feed from the point where the grinding wheel is located just in front of each machined surface. If the workpiece is not indexed correctly due to a mistake, for example, if there is a machining part in the grinding area that has a larger diameter than the part to be machined on the program,
The grinding wheel, which was being advanced at a rapid traverse speed, collided with the workpiece, potentially damaging the workpiece and the grinding wheel.

This invention solves the above-mentioned problems, and uses a measuring head to directly or indirectly detect the indexing state of the workpiece indexed to the machining position by numerical control. To provide an index confirmation device for a numerically controlled grinding machine, which determines the quality of the grinding machine and stops the grinding operation of the grinding machine when the indexing is defective, thereby preventing collision between a workpiece and a grinding wheel and their damage. The purpose is to

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of an index confirmation device for a numerically controlled grinding machine according to the present invention, in which 1 indicates a bed, 2
is a slide table installed on the bed 1 so as to be movable in the Z-axis direction (in the direction of arrows A and B) via a guide surface 3, and this slide table 2 is moved in the directions of arrows A and B by a servo motor 4 attached to the bed 1. The slide table 2 is designed to be moved in the direction B, and a headstock 5 and a tailstock 6 are respectively installed on the slide table 2 at both ends thereof. A multistage-shaped workpiece W to be ground is supported between them via centers 7 and 8. The table moving servo motor 4 is driven by a command pulse (forward, backward) sent from a numerical control circuit 10 via a drive circuit 9, and the numerical control circuit 10 is driven by a central processing unit. It consists of a computer equipped with a CPU, a data input device MDI, and a memory MEM, and the memory MEM stores machining data for grinding the workpiece W, that is, a feed control program for position indexing the workpiece and grinding wheel feed process data. In addition, data such as a reference value L (described later), an allowable deviation amount ε set based on variations in the machining allowance between the end surface W _S of the workpiece W and the cylindrical surface, etc., are stored.

Reference numeral 11 indicates an X on the bed 1 via the guide surface 1a.
This grindstone head 11 is installed to be movable in the axial direction (directions of arrows C and D), and is operated by a servo motor 12 installed on the bed 1 to move in the directions of arrows C and D. Command pulses are supplied to the table feed servo motor 12 from the numerical control circuit 10 via a drive circuit 13 in accordance with the grinding feed process. Further, the grindstone head 11 includes a grindstone 14 for grinding the workpiece W.
The grinding wheel 14 simultaneously grinds the stepped end face W _S and the cylindrical surface W _R of the workpiece W.
It has a grinding surface 14b parallel to 5.

16 is a detection device for detecting the indexing start end position of the workpiece W, and the detection device 16 is installed on the bed 1 facing the workpiece W gripped by the headstock 5 and the tailstock 6. , is movable in the direction toward and away from the workpiece W, and when the reference end W _S of the workpiece W comes into contact with the probe 17 provided at the tip, it sends a signal, and this signal is transmitted to the table. The central processing unit of the numerical control circuit 10 issues a command to confirm the output and start the grinding process.
It is now being input to the CPU. Note that the above signal is sent when the reference end surface W _S of the workpiece W is located at the intersection of the path 18 of the grinding wheel 14 and the axis 15 of the workpiece W, and the reference end surface W _S and the gauge head 17 come into contact. It is something.

Reference numeral 19 denotes an inspection head for checking the indexing of the workpiece W, and this inspection head 19 inspects the stepped end faces W _S , W _S ', W of the workpiece W as shown in FIGS. 2 and 3.
The reference surface 19a that comes into contact with _S ''... and this reference surface 1
At right angles to 9a, the cylindrical surface of the workpiece W _R , W _R ′, W _R ″...
A distance sensor 20 is installed on the lower side of this surface 19b and is lowered by γ than the upper surface. distance sensor 2 by changing the inductance of the coil.
The distance S between the end face of 0 and the cylindrical surfaces W _R , W _R ' . . . is measured. The inspection head 19 thus configured is attached to the tip of the piston rod 21a of the cylinder 21 installed on the bed 1 in the vicinity of the end face detection device 16, and the direction in which the inspection head 19 advances and retreats due to the operation of the cylinder 21 is The grinding wheel 14 is moved forward and backward along a path 22 (the angle θ relative to the workpiece axis 15 is equal) that is symmetrical to the path 18 of the grinding wheel 14 with the object axis 15 as the center. An operating circuit (hydraulic circuit) 23 is connected, and this operating circuit 2
3 is controlled by a signal from the numerical control circuit 10, and further includes a distance sensor 2.
An analog signal (voltage value) corresponding to the distance S sent from 0 is input to the central processing unit CPU of the numerical control circuit 10 via the AD conversion circuit 24.

Next, the operation of the apparatus of the present invention constructed as described above will be explained based on the flowcharts shown in FIGS. 4 and 5.

When a start command is given to the grinding machine while a multi-stage workpiece W is gripped between the headstock 5 and the tailstock 6 via the centers 7 and 8, the machining process stored in the memory MEM of the numerical control circuit 10 starts. According to the program, the end face position detection device 16 is first operated and positioned at the forward end, and then a tape feed command pulse is applied from the central processing unit CPU to the servo motor 4 via the drive circuit 9.
to move the slide table 2 in the direction of arrow A in Figure 1.
move in the direction. When the reference end face W _S of the workpiece W comes into contact with the probe 17 of the end face position detection device 16 as the slide table 2 moves, a signal is sent from the device 16 and the workpiece W reaches the indexing start position. The numerical control device 10 is notified of this fact. At this time, the reference end surface W _S of the workpiece W is located at the intersection of the path 18 of the grinding wheel 14 and the workpiece axis 15, as shown in FIG.

When the workpiece W reaches the indexing start position, the end face position detection device 16 is retracted, and in step S1 shown in FIG. 4, the central processing unit of the numerical control circuit 10
Drive circuit 1 receives grinding wheel head fast feed command pulse from CPU.
3 to the servo motor 12, which drives the servo motor 12 to rapidly advance the grinding wheel head 11 until the grinding wheel 14 reaches the machining original position shown in FIG. Next, numerical control circuit 1
When the central processing unit CRU of 0 moves to step S2, the central processing unit CPU sends indexing command pulses necessary for grinding the end surface W _S and cylindrical surface W _R of the workpiece W to regular dimensions to the servo motor. 4, the slide table 2 is moved in the direction of arrow A in response to the command pulse, and the end surface W _S and cylindrical surface W _R of the workpiece W are indexed to the processing position. When this is completed, the central processing unit CPU moves to the next step S3 and executes the program for the above-mentioned index confirmation.

FIG. 5 shows the details of this index confirmation process. In step _S31 , the central processing unit CPU
A forward command signal is sent from the test head to the test head advance/retreat operation circuit 23, thereby operating the control circuit 23 and cylinder 21 to move the test head 19 forward. At the same time, the process moves to step _S32 , starts a timer (not shown), and then proceeds to the next step S3.
Step ₃ determines whether there is a time-up or distortion. That is, the process waits until the reference surface 19a of the inspection head 19 comes into contact with the reference end surface _WS of the workpiece W before proceeding to the next step. If it is determined that the time has elapsed, the process moves to step _S34 to read the distance S between the distance sensor 20 and the cylindrical surface W _R measured by the distance sensor 20. Thereafter, the central processing unit CPU proceeds to step _S35 and determines whether S>L+ε (L: reference distance, ε: allowable positional deviation amount).

Among these determination operations, if it is determined that S>L+ε (see FIG. 6), the central processing unit
The CPU determines in step _S36 that the indexing of the workpiece W to the machining position has gone too far, displays an indexing error, and at the same time displays the indexing error in step S36.
Stop at ₇ . Also, step S3
If it is determined in _{Step 5} that S>L+ε is not satisfied, the process proceeds to the next step _S38 , where it is determined whether S<L−ε. As a result, if it is determined that S<L-ε (see Figure 7), the central processing unit CPU
In step _S39 , it is confirmed that the indexing of the workpiece W is insufficiently moved, and an abnormality in the indexing is displayed, and a stop is applied in step _S310 . Also, in step _S38 , S<L-
If it is determined that it is not ε, the central processing unit
The CPU moves to the next step _S311 , determines that the workpiece W has been indexed to a predetermined processing position, moves the inspection head 19 backward by the cylinder 21, and moves to a program in which the grinding machine starts the grinding process.

Note that when the workpiece W is correctly indexed to the processing position by numerical control, the relationship between the workpiece W and the grinding wheel 14 is such that the path 18 of the grinding wheel 14 is the same as that of the workpiece W, as shown in FIG. It passes through a point P where the end surface W _S and the cylindrical surface W _R intersect at right angles, and the distance S between the distance sensor 20 of the measuring head 19 and the cylindrical surface W _R is always a constant distance. The distance S at this time is the reference distance L mentioned above.

When the index confirmation process is completed in step S3 in FIG. 4 and normal position indexing is confirmed, the central processing unit CPU moves to step S4.
A rapid feed command pulse is supplied from the CPU to the servo motor 12, thereby driving the servo motor 12 to rapidly advance the grinding wheel head 11 until just before the grinding wheel 14 contacts the workpiece W. and whetstone head 1
1 reaches the forward end of rapid traverse, the central processing unit
The CPU moves to step S5 and supplies a grinding feed command pulse to the grinding wheel head feeding servo motor 12, and according to the command pulse, gives a cutting feed to the grinding wheel head 11, so that the end surface W _S of the workpiece W and the cylindrical surface W _R Grind to the finished dimensions. and workpiece W
When the end face W _S and the cylindrical face W _R reach the finished dimensions shown by the broken lines in Fig. 3, the central processing unit
The CPU proceeds to step S6 and supplies a fast-forward/backward command pulse to the grindstone feeding servo motor 12 to rapidly move the grindstone 11 back to the original machining position.

Next, when the processing process in step S6 is completed, the central processing unit CPU processes all the machining points (end faces W _S ′, W _S ″, etc.) of the workpiece W in step S7.
..., cylindrical surfaces W _R ', W _R ''...) is completed, and if it is not completed, the process returns to step S2 again and steps from step S2 to step S7 are performed.
is repeatedly executed according to the program in the memory MEM until all machining locations are completed. Along with this, each machining location of the workpiece W, that is, the end face W _S , W
_S ′, W _S ″… and cylindrical surfaces W _R , W _R ′, W _R ″…
are sequentially indexed to the processing position and the grindstone head 11 is operated, thereby sequentially grinding each processing location of the workpiece W in a pattern as shown by the arrows in FIG.

When it is determined that all parts of the workpiece W have been machined, the central processing unit CPU proceeds to step S8.
Then, the grindstone head 11 is returned to its original position, and the slide table 2 is also returned to its original position. The central processing unit CPU then proceeds to step S9, and the machining process for the workpiece W is completed.

In the above embodiment, when simultaneously grinding the end face (shoulder part) W _S and the cylindrical part W _R of the workpiece W using the grinding wheel 14 having the shape shown in FIG. 1, each end face W _S , W _S ′, W _S ″ and each cylindrical part W _R , W _R ′, W
The grinding allowance _R '' is the same. However, the present invention is not limited to the case where the grinding allowance at each location is the same as described above, but can also be applied when the grinding allowance is different at each location. In this case, for example, set the values of the reference distance L in multiple stages according to the machining allowance, select and install these reference distances L according to the machining allowance at each location, and execute the process shown in Fig. 5. , it becomes possible to grind with different machining allowances.

FIG. 8 shows another embodiment of the index confirmation device according to the present invention, and the difference from FIG. 26 is mounted on the slide table 2 parallel to the axis of the workpiece W, and the distance sensor 20 is mounted opposite the abutting stepped portion 25 of the reference plate 26.
A measuring head 19 having a diameter is attached to a piston rod 21a of a cylinder 21 placed on the bed 1 in the same attitude as in FIG. In this embodiment as well, the same effects as in the case of FIG. 1 can be obtained. Note that the same reference numerals as in FIG. 1 indicate the same parts as in FIG. 1.

FIG. 9 shows a modification of the inspection head according to the present invention, in which the distance sensor 20 is attached to the surface of the inspection head 19 facing the end surface W _S of the workpiece W, and the tip surface of the inspection head 19 is machined. The indexed position of the workpiece W may be confirmed by measuring the distance between the distance sensor 20 when brought into contact with the cylindrical surface W _R of the workpiece W and the workpiece end surface W _S .

FIG. 10 shows another modification of the inspection head that is applied when the path of the grinding wheel 14 is perpendicular to the axis 15 of the workpiece W. make it possible to move in the direction of
Then, the distance sensor 20 is attached to the workpiece end surface W _S side of the inspection head 19, and the inspection head 19 is connected to the workpiece W.
The index position of the workpiece W is confirmed by measuring the distance S between the distance sensor 20 and the workpiece end surface W _S when the workpiece is brought into contact with the cylindrical surface W _R of the workpiece W S . In addition, in FIG. 10, a distance sensor 27 as shown by a broken line is also provided on the surface 19c of the inspection head 19 that comes into contact with the cylindrical surface W _R , so that before the surface 19c comes into contact with the workpiece W. It is also possible to stop the forward movement of the object. In this case, there is an effect that damage to the workpiece W due to the contact of the inspection head 19 to the workpiece W can be prevented.

It goes without saying that the index confirmation method of the present invention is not limited to multi-stage workpieces as shown in FIG.

As described above, according to the present invention, the grinding wheel is moved forward and backward along the path that intersects with the axis of the workpiece, thereby simultaneously grinding the first surface parallel to the axis of the workpiece and the second surface perpendicular to the axis. In the grinding machine that performs the grinding process,
a reference surface that comes into contact with the first processed surface; and a reference surface that contacts the first processed surface;
A measuring head equipped with a sensor that faces the machined surface and detects the distance therebetween is installed so that it can move forward and backward along a path that intersects the axis of the workpiece, and this measuring head is used for position indexing. The output of the sensor when the sensor contacts the workpiece directly or indirectly is input to the determining means to determine whether the workpiece is properly indexed or not. If the object is not indexed to the correct position, this can be reliably detected and the grinding operation of the grinder can be prohibited, thereby preventing collisions between the workpiece and the grinding wheel due to indexing errors. It has the effect of being able to prevent it from happening.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing an example of an index confirmation device in a numerically controlled grinding machine according to the present invention, and FIG.
3 and 3 are explanatory diagrams showing the relationship between the workpiece, grinding wheel, and inspection head in this inventive device, respectively, FIGS. 4 and 5 are flowcharts for explaining the operation in this invention, and FIGS. 7th
The figure is an explanatory diagram showing the relationship between the workpiece and the inspection head.
FIG. 8 is an explanatory view showing another embodiment of the index confirmation mechanism section in the device of the present invention, and FIGS. 9 and 10 are explanatory views showing modified examples of the measuring head in the present invention, respectively. 1...Head, 2...Slide table, 4...
... Servo motor, 5 ... Headstock, 6 ... Tailstock,
10... Numerical control circuit, 11... Grindstone head, 12...
... Servo motor, 14 ... Grinding wheel, 16 ... End face position detection device, 19 ... Inspection head, 20 ... Distance sensor, 21 ... Cylinder, 23 ... Measurement head advance/retreat operation circuit, 24 ... A -D conversion circuit,
CRU...Central processing unit, MDI...Data input device, MEM...Memory, W...Workpiece.

Claims (1)

[Claims] 1 Program controlled by a numerical control circuit, the grinding wheel is moved forward and backward along a path that intersects with the axis of the workpiece, and one of the grinding wheels is parallel to the axis of the workpiece and the other is perpendicular to the axis of the workpiece. In a grinding machine that grinds a workpiece having a second machining surface, a reference surface that comes into contact with the first machining surface and the second machining surface are provided.
The grinding machine is provided with a sensor that faces the machined surface of the grinding machine and detects the distance between the machined surface and the second machined surface, and is capable of moving forward and backward along a path that intersects with the axis of the workpiece held on the headstock of the grinding machine. A measuring head provided on the workpiece, a positioning means for positioning the measuring head by directly or indirectly contacting the workpiece whose position has been determined, and an output of the sensor in this contact state being a specified value. An index confirmation device for a numerically controlled grinding machine, comprising a determination means for determining whether or not a workpiece index is good or not based on the presence or absence of a workpiece index.