JPH0116622B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention uses a grinding wheel that is moved in a guiding direction inclined to the workpiece axis and has a first grinding surface parallel to the workpiece axis and a second grinding surface orthogonal to the first grinding surface. The purpose of the grinding device is to perform traverse grinding of a cylindrical part at the same time by cutting a grinding wheel at the end of the stepped part in the traverse process. The object is to enable even the end face of a step part to be processed with high efficiency and precision. When traverse grinding a cylindrical part of a workpiece with a stepped part using a conventional angular grinder,
The cylindrical part is machined to the finished dimensions by performing a traverse operation so that the end face of the stepped part does not engage with the second grinding surface of the grinding wheel, and then the end face of the stepped part is manually operated on the second grinding surface of the grinding wheel. Since traverse grinding of the cylindrical portion and grinding of the step end surface were performed separately, such as engaging at the cylindrical portion and machining the step end surface, the machining time became long and the machining efficiency decreased. Furthermore, Japanese Patent Application Laid-Open No. 53-103295 discloses a grinding machine capable of grinding the end face of a step part in parallel with traverse grinding of a cylindrical part; Every time the grinding wheel cuts in a direction that is inclined to the workpiece axis at the end, a correction operation is required to release the workpiece by a predetermined amount in the axial direction, making the machining cycle complicated and the program complicated. However, there was a drawback that the cycle time was redundant and machining efficiency could not be improved. In view of these conventional drawbacks, the present invention is designed to allow the grinding wheel to perform cutting on the stepped part side of the workpiece without a correction operation in the axial direction of the workpiece. The work table is positioned so that the step end face of the workpiece is at a specific position to be ground by the second grinding surface when the finishing dimension position of Each time the work table is positioned at this specific position, the grinding wheel is cut by a predetermined amount, and then the work table is caused to traverse. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of an angular grinding machine according to the present invention, in which a grindstone head 21 supporting an angular grinding wheel G slides along guide surfaces 22 and 23 formed on a bed 20. A feed screw 26 connected to a pulse motor 25 via a gear mechanism 24 is screwed into the grindstone head 21 . On the other hand, the work table 27 is slidably guided in the Y-axis direction along guide surfaces 28 and 29 formed on the front surface of the bed 20, and is driven by a pulse motor 30. A feed screw 31 is screwed together. A headstock 32 and a tailstock 33 are placed on the work table 27,
A workpiece W having a wide cylindrical portion Wa and a stepped portion adjacent to the cylindrical portion is rotatably supported by the center of the headstock 32 and the tailstock 33. The rotation axis Ow of this workpiece W is the work table 27
It is parallel to the guide surface of the grinding wheel G, and the path 3 of the grinding wheel G
8 and forms an acute angle θ. On the outer peripheral surface of the grinding wheel G, there is a rotation axis of the workpiece W.
A first grinding surface Ga that is parallel to Ow and narrower than the grinding width of the cylindrical part of the workpiece W, and a second grinding surface Gb that is perpendicular to this and wider than the step part of the workpiece W are formed,
The cylindrical portion Wa and the end surface Wb of the stepped portion of the workpiece W are ground by the first grinding surface Ga and the second grinding surface Gb. Since the path 38 of the grinding wheel G forms an acute angle θ with the rotational axis Ow of the workpiece W, when the grinding wheel G is moved by a predetermined amount L in the direction of the path 38, the first grinding surface Ga will move in the radial direction of the workpiece W. (X-axis direction) Lsinθ
This means that the amount of movement in the radial direction must be converted. Therefore, in this embodiment, the pulse motor 25 is adjusted by setting the gear ratio of the gear mechanism 24 to a predetermined value in order to eliminate the need for converting the amount of radial movement.
When n pulses with a set unit of Δl are distributed to It is arranged to move by a distance nxΔn equal to the number of pulses given to the motor 25. Furthermore, the cylindrical part of the workpiece W is placed on the bed 20.
Cylindrical part Wa to the sizing circuit 39 that determines the dimension of Wa.
dimension measuring head 40 which sends out a signal representing the diameter of the
and an end face position measuring head 4 that sends a signal representing the position of the reference end face Ws to an end face position detection circuit 41 that positions the workpiece W to the reference position in the Y-axis direction.
2 is provided. Next, a control device for performing traverse grinding using the angular grinder having the above configuration will be explained. 43 is a small arithmetic processing unit (hereinafter referred to as CPU) such as a microcomputer, and this CPU 43 includes a plurality of digital switches DS0 to DS7 that set data necessary for traverse grinding, and a drive that drives pulse motors 25 and 30. Unit DU
1. DU2 and interrupt signal for pulse distribution
A pulse distribution command circuit 44 that generates INTS is connected. The CPU 43 executes the program stored in the internal memory to perform the necessary control to perform the traverse grinding cycle shown in FIG. 3.
In this embodiment, until the cylindrical portion Wa reaches the dimension at which rough grinding is completed and the sizing signal AS1 is output from the sizing circuit 39, the grinding wheel is turned by V ₁ at the first traverse end (rightward advancing end of the work table). When the first grinding surface Ga of G is fed and the sizing signal AS1 is output, the depth of cut at the first traverse end is decreased from _V1 to _V2 .
When the cylindrical portion Wa reaches the finished size and the sizing signal AS2 is output from the sizing circuit 40, the grinding process is completed and the grinding wheel G is moved backward. First grinding surface Ga during rough grinding and fine grinding
The data of the cutting depth V ₁ , V ₂ and the cutting speed Fc are set in digital switches DS3 to DS5, and the data of the traverse stroke and the traverse speed are set to the digital switches DS3 to DS5, and the data of the traverse stroke and the traverse speed determine the leftward end of the work table which is the second traverse end. Data Ft is set to digital switches DS6 and DS7. In parallel with such traverse grinding, the step end face
To grind Wb, when the grinding wheel is fed until the first grinding surface Ga of the grinding wheel is located at the outer peripheral surface of the cylindrical part Wa during finishing, the step end face is ground to a predetermined dimension. It is necessary to accurately control the first traverse end according to the finished diameter of the circumferential portion Wb. Now, as shown by the two-dot chain line in Fig. 4, the workpiece W
If the position where the intersection point Po of the reference plane Ws plane and the rotation center Ow of the workpiece intersects with the extension line of the path 38 is the reference position of the work table 27, then the work table 27 is referenced by L ₁ − (D ₁ /2tanθ). Y from position
By moving the work table 27 in the axial direction, the work table 27 can be indexed to the first traverse end;
If a traverse operation is performed using this first traverse end as a starting point, the cylindrical portion Wa and the end surface Wb can be simultaneously ground. Note that L ₁ indicates the distance between the reference surface Ws and the finished position of the step end surface Wb, and D ₁ indicates the finished diameter of the cylindrical portion Wa. The CPU 43 has a function to automatically index to this first traverse end,
Digital switches DS0 and DS1 are set with data of distance L ₁ and finished diameter D ₁ necessary for performing index control. Further, in order to prevent the pulse motor from stepping out of step at the end of the traverse, the CPU 43 performs slow-up control at the start point of the traverse stroke, and performs slow-down control at the end point. The pulse distribution command circuit 44 is for controlling this slow-up and slow-down, and as shown in FIG. DA that converts speed data F to analog value
Slow-up command from converter 61 and CPU 43
Flip-flops SUF and SDF are set respectively when SUC and slowdown command SDC are given, and when flip-flop SDC is set, a gradually increasing voltage signal as shown in FIG. 6a is output, and when flip-flop SDF is set, the A voltage signal generation circuit 62 that outputs a voltage signal that gradually decreases as shown in FIG. Flip-flop PGF and gate to enable and disable pulses output from converter 63
The pulse output from this VF converter 63 is sent to the CPU as an interrupt signal INTS.
43. Since the CPU 43 distributes one pulse to a predetermined axis each time the interrupt signal INTS is given, the voltage signal generation circuit 62
When a gradually increasing or decreasing voltage signal is output from , the period of pulse distribution is increased or decreased accordingly,
A slow-up or slow-down occurs. Next, the specific operation of the CPU 43 is shown in Figure 7a.
This will be explained according to the flowcharts from b to FIG. 10. Work table 2 on which the workpiece W is currently attached
7 is located at the workpiece attachment position shown in FIG. 11a, when an unillustrated start switch is pressed,
The CPU 43 has a control routine shown in FIG. 7a and b.
Run COR. In this control routine COR,
Programmatic cycle counter SC
It is designed to identify the process being executed. Table 1 shows the steps corresponding to the count values of the cycle counter SC.

[Table] At the start of operation, the cycle counter SC is preset to -2 at step (12) of the control routine COR, so the CPU 43 starts at step (13).
Then, the process moves to step (21), and indexing to the reference position is controlled. When the process moves to step (21), the Y-axis flag that specifies the movement direction is set, and at the same time, at step (22), the speed data Fw for table indexing stored in the memory of the CPU 43 is sent to the pulse distribution command circuit 44. Output and 8th
Jump to the pulse distribution rutitin PGR shown in the figure. The pulse distribution routine PGR distributes pulses to designated axes, and is executed once following the control routine COR, as well as every time an interrupt signal INTS is generated from the pulse distribution command circuit 44. , each time this pulse distribution routine is executed, one distribution pulse is sent in the direction specified in step (65). In this case, the speed data Fw for indexing is output to the pulse distribution command circuit 44, so pulses with a period corresponding to the speed data Fw are distributed to the Y axis, and the work table 27 is moved to the right at the indexing speed Fw. will be advanced. Cycle counter SC is -2
If so, after distributing the pulses in step (65), the process moves from step (67) to step (68), and the end face position detection circuit 41 outputs the index completion signal PES.
Determine whether the is output. If the index completion signal PES is not output, the process returns to the main routine (not shown) and waits for an interrupt from the pulse distribution command circuit 44, and the work table 27 is
When the reference position shown in FIG. Return to routine COR. When the count value of the cycle counter SC becomes -1, the process moves from step (14) to step (23).
Control is performed to index the work table 27 to the first traverse end. That is, in step (23),
Movement amount of work table 27 L ₁ − (D ₁ /2tanθ)
After setting the movement amount counter MVC, the Y-axis flag is set in steps (24) and (25), the indexing speed data Fw is output, and the process jumps to the pulse distribution routine PGR. Jumping to the pulse distribution routine PGR:
Pulse distribution command circuit 44 in the same manner as in the above case.
Every time an interrupt signal INT is sent from , a pulse is output to the Y axis. In addition, in this case, the pulse distribution routine PGR is executed every time a pulse is sent to the Y axis.
In step (66), the movement amount counter MVC is subtracted. The work table 27 is indexed to the first traverse end shown in FIG.
If the count value of MVC becomes zero, this is determined in step (71) of the pulse distribution routine PGR, and the process moves from step (71) to step (74) via step (73). In addition, in this case, since the cycle counter SC is -1, the process moves from step (14) to step (75), gives a hydraulic forward command to a hydraulic circuit (not shown), and moves the grinding wheel G to the hydraulic forward end. let Thereafter, in step (77), 1 is added to the count value of the cycle counter SC to make the count value zero, and the process returns to the control routine COR. Note that since the flip-flop PGF in the pulse distribution command circuit is reset in step (73), pulse distribution is not performed during hydraulic advance. When the count value of cycle counter SC becomes zero,
Moving from step (15) to step (26), the rapid traverse amount V ₀ is set in the movement amount counter MVC, and at the same time, in steps (27) and (28), the X-axis flag is set and the rapid traverse speed data Fr is output. Jump to pulse distribution routine PGR. As a result, pulses are distributed to the X-axis until the count value of the movement amount counter MVC becomes zero, and the grinding wheel G is moved to the fast forward forward end position. Travel amount counter
When the count value of MVC becomes zero, the process moves from step (71) to step (73), and in step (77), the count value of cycle counter SC becomes 1 and the process returns to the control routine COR. When n pulses corresponding to the rapid feed amount V ₀ are distributed to the X axis, the grinding wheel G is moved by nxΔl/sinθ along the path 38, and the first processing surface Ga of the grinding wheel G is switched to the digital switch DS3.
It is moved accurately by the fast forward amount V ₀ set in . When the control routine COR returns, since the count value of the cycle counter SC is 1, the process moves from step (16) to step (33), and the depth of cut at the first traverse end is controlled. Step (33) is a step to determine whether the process to be performed is a rough grinding depth of cut. If it is a rough grinding depth of cut, step (34) is a step to determine the depth of cut V ₁ set in the digital switch DS3. Set the travel amount counter MVC, and if it is not a rough grinding cut, proceed to step (35) and turn on the digital switch.
The depth of cut V ₂ set in DS4 is calculated by the movement counter.
Set to MVC. In this case, since the coarse grinding flag is set at the start of operation, the process moves to step (34) and the depth of cut _V1 is set in the movement amount counter MVC. After this, in step (36), the X-axis flag is set, and in step (37), the cutting feed rate FC is output, and the process jumps to the pulse distribution routine PGR. Since the forward end position of the grinding wheel G in the cutting process during rough grinding and fine grinding is managed by the sizing signal from the sizing circuit 39, the movement amount counter
Sizing circuit 39 even if the MVC count value does not become zero
When a sizing signal is sent from the grinding wheel G, the feeding of the grinding wheel G must be stopped. Therefore, if the count value of the movement amount counter MVC is not zero, the process jumps from step (72) to the sizing routine TCR shown in Fig. 9, and checks the sizing signal every time a pulse is sent to the X axis. There is. Since no sizing signal is sent during the first cut, pulses are distributed to the X-axis at a cycle according to the cut feed rate FC until the count value of the movement amount counter MVC becomes zero. As a result, the grinding wheel G is moved by V ₁ /sinθ along the path 38 at a speed of FC/sinθ, and the first grinding surface Ga and the second grinding surface
Gb are moved by V ₁ and V ₁ /tanθ, respectively.
Through this cutting operation, the first grinding surface Ga of the grinding wheel G is cut into the cylindrical portion Wa of the workpiece W as shown in FIG. A cut is made on the side and the step end face Wb is processed. When the content of the movement amount counter MVC becomes zero, the count value of the cycle counter SC becomes 2 in step (77).
and returns to the control routine COR. When the count value of the cycle counter SC reaches 2, the process moves from step (17) to step (30), and control is performed to move the work table 27 to the left. This is done by setting the traverse amount Lt in the movement amount counter MVC in step (30), and setting Y in step (31).
After setting the axis flag, this is done by outputting the traverse speed data Ft to the pulse distribution command circuit 44 in step (32) and jumping to the pulse distribution routine PGR. The pulse distribution routine PGR is used to control slow-up and slow-down during the traverse stroke.
The program jumps from step (62) to the speed control routine VCR shown in FIG. This program is
At the start of movement, the slow-up flag SUF in the pulse distribution command circuit 44 is set and an interrupt signal output from the pulse distribution command circuit 44 is set.
The frequency of INTS is gradually increased, and when the work table 27 moves to the slowdown start position, a slowdown flag SDF is set to gradually decrease the frequency of the interrupt signal INTS output from the pulse distribution circuit 44. . Therefore, as shown in FIG. 12, the traverse speed of the work table 27 gradually increases at the start of movement and gradually decreases when the work table 27 moves to the slowdown position. When the traverse process is finished and the work table 27 is located at the leftward advance end (second traverse end) as shown in FIG. The count value of is set to 3, and the control routine
Return to COR. Cycle counter SC count value is 3
When this happens, the process moves from step (18) to step (38), and control is performed to move the work table 27 to the right. In other words, in step (38), the traverse amount Lt
is set in the movement amount counter MVC, and the Y-axis flag is set in step (39).Then, in step (40), the traverse speed Ft is output and the pulse distribution routine PGR jumps to the pulse distribution routine PGR. is distributed on the Y axis,
The work table 27 is moved to the right at a traverse speed Ft to the first traverse end. It should be noted that slow-up and slow-down control is also performed in this traversal process of moving the table to the right. When the rightward movement of the work table 27 is completed and the work table 27 is located at the first traverse end, the count value of the movement amount counter MVC becomes zero, so this is determined in step (71) of the pulse distribution routine PGR. Move to step (73).
In this case, the count value of the cycle counter SC is 3.
Therefore, at step (78), the cycle counter
Set the count value of SC to 1 and return to the control routine COR. When the count value of cycle counter SC becomes 1,
The cutting of the grinding wheel G at the first traverse end is performed again. As a result, the first grinding surface Ga cuts into the cylindrical portion Wa, and the end surface of the stepped portion is ground by the second grinding surface Gb. After this,
The work table 27 is reciprocated in the same manner as in the above case, and the cylindrical surface Wa is machined. When such a grinding cycle is repeated and the cylindrical portion Wa reaches the dimension where rough grinding is completed, a rough grinding completion signal AS1 is output from the sizing circuit 39, and the CPU
43. Then, the CPU 43 determines this in step (82) of the sizing control routine TCR, sets the fine polishing flag in step (83), and
I remember that I started fine grinding. When fine grinding begins, the depth of cut of the first grinding surface Ga of the grinding wheel G at the first traverse end is reduced from V ₁ to V ₂ , and the cylindrical surface
Wa is finely ground. Further, when the cylindrical portion Wa of the workpiece W reaches the finished size and the sizing signal AS2 is sent from the sizing circuit 39, step (84) of the sizing control routine TCR is performed.
This is determined in step (85), and the machining completion flag FINF is set. As a result, when the work table 27 returns to the first traverse end, the grinding wheel is quickly returned by hydraulic pressure, and then returned to its original position by the pulse motor 25. By such grinding, the cylindrical surface is processed with high precision by traverse grinding, and at the same time, the end face Wb of the stepped portion is also processed with high precision. In addition, since the grinding wheel does not cut at the second traverse end, the second grinding surface of the grinding wheel does not hit the end face of the stepped part at the traverse speed, preventing burns from occurring on the end face of the stepped part. can. As described above, in the traverse grinding device according to the present invention, the first grinding surface of the grinding wheel is adjusted to the outer circumferential surface of the cylindrical portion when finishing the cylindrical portion based on the preset step end face dimensions and the cylindrical portion dimensions. When the grinding wheel is cut into the position, the end face of the stepped part is ground to a predetermined dimension by the second grinding surface. This position is determined by calculation, and this position is positioned as one traverse end, and the grinding wheel is Since the traverse movement is performed after making the cut, the end face of the stepped part and the cylindrical part of the stepped part can be ground to the finished dimensions by simply positioning the traverse table once and then cutting with the grinding wheel. Therefore, it has the advantage of shortening cycle time.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a schematic plan view of an anguilla grinding machine with an electric circuit, and Fig. 2 shows the relationship between the depth of cut of the grinding wheel and the amount of movement of the grinding surface. 3 is a diagram showing the entire process of the grinding cycle, FIG. 4 is a diagram for explaining the positioning of the work table, and FIG. 5 is a diagram showing the specific configuration of the pulse distribution command circuit 44 in FIG. 1. 6A and 6B are diagrams showing the slow-up and slow-down characteristics of the pulse distribution command circuit 44, and FIGS. 7A and 7B to 10 are flowcharts showing the operation of the arithmetic processing unit 43 in FIG. 1. FIG. 11 is a diagram showing the positional relationship between the grinding wheel and the workpiece in each process of the grinding cycle, and FIG. 12 is a diagram showing changes in the moving speed of the work table 27 in the traverse process. 21... Grinding wheel head, 25, 30... Pulse motor, 27... Work table, 32... Headstock,
33...tailstock, 38...path, 39...sizing circuit, 40...dimension measuring head, 41...end face position detection circuit, 42...end face position measuring head, 43...
...Arithmetic processing unit, 44...Pulse distribution command circuit,
DS1 to DS7...Digital switch, G...Grinding wheel, Ga...First grinding surface, Gb...Second grinding surface, Lt
... Traverse stroke, V ₁ , V ₂ ... Grinding wheel cutting depth,
W...Workpiece, Wa...Cylindrical part, Wb...Step end face.

Claims (1)

[Claims] 1. A work table that rotatably supports a workpiece having a step portion projecting in the radial direction and a cylindrical portion extending away from the step portion and is guided to be movable in parallel to the axis of the workpiece, and the workpiece A grinding wheel having a first grinding surface parallel to the axis of the workpiece and a second grinding surface perpendicular to the first grinding surface is rotatably mounted and guided so as to be movable in a guide direction forming a predetermined angle with the workpiece axis. a grindstone head, a work table feed device that moves the work table in response to command pulses, a grindstone feed device that moves the grindstone head in response to command pulses, and finished dimensional positions of the cylindrical portion and the stepped portion. and a finishing dimension position setting means for setting the finishing dimension, and when the first grinding surface of the grinding wheel reaches the finishing dimension position of the cylindrical portion based on the finishing dimension position setting means, the end face of the stepped portion becomes the second grinding surface at the same time. a calculation means for calculating a first position such that the stepped portion is ground to a finished dimension position; and a first command pulse for sending a command pulse for positioning the work table to the first position to the work table feeding device. a control means, and a second command pulse control for sending a command pulse to the grinding wheel head feeding device to cut the grinding wheel by a predetermined amount along the guide direction each time the work table is positioned at the first position. and after completion of cutting by the second command pulse control means, the work table is moved in a direction in which the second grinding surface of the grinding wheel is separated from the step end face, and at the end of the stroke, the direction of movement is reversed and the work table is moved. A traverse grinding device comprising: third command pulse control means for sending command pulses to the work table feeding device to position the work table at the first position.