JPS58186562A - Internal grinding equipment - Google Patents

Abstract

PURPOSE:To shorten the time of a grinding cycle, by turning on an operating switch to rapidly move a grinding wheel forth toward the inside surface of a workpiece and thereafter turning off the switch and starting the multi-step grinding cycle on the basis of the position of the grinding wheel. CONSTITUTION:An operating switch is pressed to rapidly move a grinding wheel 20 forth to a position corresponding to the inside diameter of a workpiece W, to enable to actual rough grinding of the workpiece from a first grinding step. As a result, the number of grinding steps is reduced and useless dressing is avoided. If the pressing of the operating switch is not undone when the rapidly moved quantity A of the grinding wheel 20 under the pressing of the switch has increased to be equal to a roughly ground quantity D2, the distribution of pulses is stopped and a jump is thereafter executed to a step for transfer to fine grinding so that the time of a grinding cycle is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an internal grinding device, and particularly to an internal grinding device that grinds the inner surface of a workpiece by multi-step grinding.

In internal grinding machines, it is common practice to dress the grinding wheel during the grinding process, but especially when grinding a workpiece with a large internal diameter, it is necessary to dress the grinding wheel every time the grinding wheel is fed in a small amount. need to be done and the time spent on dressing increases.

By the way, in this type of internal grinder, the rough grinding start position is set in consideration of variations in the inner diameter dimension of the workpiece due to pre-processing. Therefore, depending on the inner diameter of the workpiece, even if the grinding wheel is rapidly advanced to the rough grinding starting position N, there will still be a considerable gap between the grinding wheel and the inner surface of the workpiece, and the grinding wheel will move once or twice. A situation arises in which the grinding process is not actually performed even if the machine is fed several times, resulting in idle operation. Moreover, the problem is that after the grinding wheel has been fed a certain amount, a dressing operation is performed even though no grinding process is performed, and the grinding wheel is completely wasted and the time is lost. becomes larger.

The present invention has been made in view of this problem, and allows the operator to disable the predetermined multi-step grinding cycle by operating an operation switch, and rapidly advance the grinding wheel to the required position. The purpose is to shorten cycle time.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 10 indicates a bed of a numerically controlled internal grinding machine, and on this bed 10, two horizontal guide surfaces: Ll, 12 are formed in directions perpendicular to each other.

A table 1 with a headstock 13 installed on one guide surface 11
4 is mounted so as to be slidable in the X-axis direction, and this table 14
is connected to a servo motor 15 and its feed is controlled via a feed screw in a circuit.

A drive face plate 16 for rotationally driving the workpiece W is rotatably supported on the headstock 11 around an axis parallel to the sliding direction of the table 14, and is rotationally driven by a drive motor 17.

On the other guide surface 12, a grindstone head 18 slides in the Y-axis direction.
The grinding wheel head 18 is mounted on a grinding wheel and its feeding is controlled via a feed screw of a circuit connected to a servo motor 19. A grinding wheel 2o is rotatably supported on the grinding wheel head 18 around an axis parallel to the axis of the driving face plate 16, and is rotationally driven by a grinding wheel drive motor 21.

23 is a dressing tool placed on the table 14.

FIG. 2 shows a control circuit for controlling the internal grinding machine configured as described above, and in the same figure, 30 is the servo motor 15, 19.
A numerical controller a distributes pulses to drive circuits 31 and 32 that respectively drive the workpiece W and controls the dressing of the grinding wheel 2o. Inter 7 Ace 35
．． It is composed of 36.

Connected to the interface 7/8 35 are a data writing device 37, an operation panel 40 equipped with a cycle start switch 38, an operation switch 39, etc., a manual pulse generator 41, a position detector 42, 43, etc., and an interface. 36 is connected to drive circuits 31 and 32.

The memory 34 consists of a core memory, and this memory 34
A data area DA into which data is written by the 4iJ data writing device 37 is provided inside.

This data area DA contains various data shown in Fig. 3,
That is, the dry grinding mouse D1 from the original position o1 of the grinding wheel 2o,
Rough grinding 14D2 from the original position 01 of the grinding wheel 2o to the fine grinding start position, fine grinding amount D3, step grinding amount D4, ■, and fine dressing cutting depth D'7. D8, data of each distance from the end face position 02 of the grinding wheel 20 at the original position of the table 14 to the grinding position, the dressing start position, and the dressing end position D9.1) IQ.

Data Tl and T2 are written, respectively.

Further, in the RAM area RA in the memory 34, there is a register for storing data Ai representing the movement position of the grinding wheel 2o starting from the original position flol of the grinding wheel 2°, and a register for storing data Ai to which this data is stored. A register that stores data a representing the number of times of step grinding, and data n representing the number of step grinding operations.
A register is configured to store the .

Next, the operation of the numerically controlled internal grinding machine having the above configuration will be explained, focusing on the processing operation of the arithmetic processing unit 33.

When the cycle start switch 38 is operated, the arithmetic processing unit 33 executes the program shown in FIG. 4 to process the inner surface of the workpiece W by multi-step grinding.

That is, the arithmetic processing unit 33 first performs step (101
), the contents of the register storing the number of step grinding n are cleared to zero, and the contents of the register storing the reference movement 1a are cleared to zero. Step (102
), the number of e-pulses according to the data D9 is distributed to the X-axis drive circuit 31 at the instep feed rate FO, and the table 1
A predetermined amount of 4 from the original position, dry grinding i, l D l, and step grinding Lf, D 4 are added by n times the value, but y
In the J period state, n = O, and unless the operation switch 39 is operated, it is a-0, so the number of θ pulses corresponding to the dry grinding amount D1 is sent to Y at the dry grinding feed rate F1.
The dynamic drive circuit 32 adds the distribution a, the dry grinding amount D1, and the value n + 1 times the step grinding amount D4, and it is determined whether this added value is smaller than the rough grinding amount D2, and if it is smaller, the next Step grinding amount D4 in step (107)
The number of O pulses corresponding to YNI at rough grinding feed rate F2
The grinding wheel 20 is moved forward by a predetermined amount for rough grinding, and the inner surface of the workpiece W is being roughly ground. After that, spark out occurs at the cutting end of grinding wheel 2o for a certain period of time T1
When the time is up (step 108), 1 is added to the register that counts the number of step grinding n in the next step (109), and n == 1.
becomes.

Subsequently, in step (110), (a-1-DI+
n×D4] is calculated, and the corresponding number of pulses are distributed to the Y drive circuit 32 at a fast forwarding speed FO, and the grinding wheel 2
0 is fast forwarded or backwardd by a predetermined amount. The amount of retreat of this grinding wheel 2o is the same as the amount of advance of the grinding wheel 20 from the original position 01 last time, and the grinding wheel 20 is returned to the original position 01.

Subsequently, in step (Ill), a movement calculation is performed by subtracting the data DIO from the data D9, and a number of pulses corresponding to the movement amount are distributed to the X-axis drive circuit 31 at a fast forward speed FO, and the table 14 is moved to the desired position. The dressing tool 23 is moved a certain amount to position the dressing tool 23 at the dressing opening position. In step (112), a movement amount is calculated by adding the rough dressing depth D7 to the relief amount D12, and a number of θ pulses corresponding to the movement amount are distributed to the Y drive circuit 32 at the dry grinding feed rate F1. , the grinding wheel 20 cuts into the dressing tool 23 by a predetermined amount. In step (113), the data DI
The amount of movement is calculated by subtracting the data Dll from O, and a number of pulses corresponding to the amount of movement are distributed to the drive circuit 31 at a rough dressing traverse speed F4, and the grinding wheel 20 is roughly dressed.

Next, the number of e-pulses corresponding to the relief amount D12 is distributed to the drive circuit 32 at the dry grinding feed rate Fl (step 114).
, the grinding wheel 20 is released by a predetermined amount from the tip of the dressing tool 23, and in the next step (115), the content A of the position register that stores the movement position of the grinding wheel 2° is cleared to zero, and the grinding wheel 20 after dressing is The original position 01 of loading 0 is determined. Next, in step (116), the amount of movement is calculated by subtracting the data Dll from the data D9, and a number of θ pulses corresponding to the amount of movement are sent to the drive circuit 3 at the fast forward speed FO.
1 and return to step (IQ5). Below, the above-described operations from steps (105) to (116), that is, the step grinding operation and the dressing operation are repeated alternately. Grinding wheel 2o
The rapid retraction amount becomes an amount that is sequentially increased by the step grinding amount D4.

However, in the step (10), Dl + (21
+1)×D4 is determined to be smaller than the rough grinding amount D2, in other words, if the remaining rough grinding amount D2 is less than the step grinding amount D4, step (117) [
be jumped. In the darning step (117), (D2- (*+DI+nXD4))i"Wi'14
sat'L, the number of ○ pulses corresponding to the remainder of the rough grinding amount D2 is distributed to the Y drive circuit 32 at a rough grinding feed rate F2 as the last step grinding amount in rough grinding, and then for a certain period of time T1 Spark out (step 11)
8). Next, in step (119) - Rough grinding amount D
The number of {circle around (1)} pulses corresponding to 2 are distributed to the Y drive circuit 32 at a rapid feed speed FO, and the grinding wheel 20 is rapidly moved backward by a predetermined amount to complete the rough grinding process.

In the following steps (120) to (124), the grinding wheel 2o is dressed in the same cycle as in steps (111) to (114) and (IIJ), but the difference is that the cutting depth of the grinding wheel 20 with respect to the dressing tool 23 is becomes the fine dressing cutting depth D8, and the traverse speed becomes the fine dressing traverse speed F5.

When the fine grinding is completed, in step (125), a number of e-pulses corresponding to the rough grinding amount D2 are distributed to the Y drive circuit 32 at a grinding feed rate Fl, and the grinding wheel 2o is moved to the inner surface of the rough-ground workpiece. Advance the idle grinding feed until it touches the In step (126), a number of θ pulses corresponding to the fine grinding amount D3 are distributed to the drive circuit 32 at a fine grinding feed rate F3, and the grinding wheel 20 is advanced by a certain amount of fine grinding feed to finely grind the inner surface of the workpiece W. Grind. However, the spark out occurs at the forward end of the grinding wheel 20 for a certain period of time T.
2 and it times up (step 127)
Then, in the next step (128), a number of ■ pulses corresponding to the movement amount obtained by adding the rough grinding amount D2 and the fine grinding amount D3 are distributed to the drive circuit 32 at the rapid traverse speed FO, and then in step (12
In step 9), content A of the position register, which stores the movement position of the grinding wheel 20, is cleared to zero. In step (130), pulses corresponding to data D9 are transmitted at fast forward speed F.
0 to the X-axis heavy drive circuit 31, the table 14 is returned to its original position, and the multi-step grinding cycle is completed. This cycle diagram is shown in Figure 6.

In the above explanation, the idle grinding feed of the grinding wheel 20 is performed to the previous grinding end position, but due to the deflection of the grinding wheel shaft that occurs during grinding, the grinding wheel 20 moves by the amount of the deflection due to the idle grinding feed. Since it is cut into the inside,
In order to avoid this, for example, the dry grinding feed amount may be subtracted by a correction amount ε that takes into account the deflection of the grindstone shaft, and this correction amount ε may be added to the step grinding amount D4 before feeding.

By the way, when the operator presses the operation switch 39 while the table 14 is positioned at the grinding position, the multi-step grinding cycle program described above is invalidated, and in step (131) shown in FIG. The θ pulse is distributed to the shaft drive circuit 32 at the dry grinding feed rate F1, and the grinding wheel 2o is moved forward in the dry grinding feed speed. For example, if the operating switch 39 is released when the grinding wheel 20 contacts the inner surface of the workpiece and a spark is generated, step (13)
In 4), pulse distribution to the drive circuit 32 is stopped,
In the next step (135), data A representing the moving position of the grinding wheel 2o is read out, and a value a obtained by subtracting the dry grinding MD1 from the data A is stored in the register as the reference moving amount a. Furthermore, in step (136),
The contents of the register storing the number of times n of step grinding are cleared to zero, and then the process jumps to step (1'o6) in FIG.

In step (106), the reference movement amount a, the idle grinding amount D1, and the step grinding amount D4 (7) n -1-1
It is determined whether the sum of the times and the rough grinding amount D2 is smaller than the rough grinding amount D2, and if it is smaller, the next step (1
In step 07), the grinding wheel 20 is advanced by step grinding iD4 from the position to which it was advanced by operating the operation switch 39, and then the above-mentioned multi-step grinding cycle is performed.
Row -+ru.

In this way, by operating the operation switch 39, the grinding wheel 20
can be rapidly advanced to a position corresponding to the inner diameter dimension of the workpiece W, and it becomes possible to actually perform rough grinding of the workpiece W from the first step grinding. This reduces the number of step grinding operations and eliminates unnecessary dressing.

However, the operation of the operation switch 39 described above does not necessarily need to be performed at the beginning of the grinding cycle. For example, even if the grinding wheel 2o is sent by the step grinding amount D4, it is necessary to operate the operation switch 39 after confirming that the actual grinding process is not performed. Then, the operation switch 39 may be operated, and in this case as well, the step grinding amount Wi up to that point is cleared to zero, so after operating the operation switch 39, it is counted as the first step grinding. It becomes like this.

In addition, if the suppression of the operation switch 39 is not released even if the movement amount A of the grinding wheel 2o by operating the operation switch 39 is rapidly advanced in a groove that matches the rough grinding MD2, step (132) in FIG. Based on the determination result, step (13)
In step 3), pulse distribution is stopped, and then the process jumps to step (126) to proceed to fine grinding.

In the above-described embodiment, an example was described in which the inner surface of the workpiece W was ground by plunge grinding, but it goes without saying that the present invention can also be applied to traverse grinding.

As described above, according to the present invention, the grinding wheel is sent incrementally by the step grinding amount to grind the workpiece.
The inner surface of the workpiece is ground to a predetermined dimension through a multi-step grinding cycle in which a step grinding operation and a dressing operation of dressing the grinding wheel are repeated alternately, and the multi-step grinding cycle is performed while the operation switch is operated. is disabled, the grinding wheel is rapidly advanced toward the inner surface of the workpiece, and the multi-step grinding cycle is started based on the position of the grinding wheel when the operation switch is released. As a result, empty step grinding is eliminated and unnecessary dressing is no longer performed, which allows the number of step grinding to be reduced according to the inner diameter dimension of the workpiece. It has a feature that can significantly shorten the time.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic plan view of a numerically controlled internal grinding machine, FIG. 2 is a control circuit diagram for controlling the water-containing internal grinding machine, and FIG. Figures 4 and 5 show the relationship between the workpiece, grinding wheel, and dressing tool, Figure 2 shows the operation of the water processing unit, and Figure 6 shows the grinding process. It is a diagram showing a cycle. 13... Headstock, 14... Table, 15 War...v
-Ho%-1,15... Grinding head, 19... Servo motor, 20... Grinding wheel, 234I/0 dressing tool, W... - Workpiece, 30... φ numerical control device, 33・
-Fist calculation processing device, 39...operation switch. Patent applicant Toyota Machinery Co., Ltd. Figure 5

Claims (1)

[Claims] (1) Relative movement of a table equipped with a headstock that rotationally drives a workpiece and a grindstone head bearing a grinding wheel (jton) that grinds the inner surface of the workpiece in the X and Y axes directions that intersect with each other.
A dressing tool is installed on the ML table to perform the step grinding operation in which the workpiece is ground by feeding the AU grinding wheel by the step grinding amount, and dressing the grinding wheel. The internal grinding device is in the process of grinding the inner surface of the workpiece to a predetermined size through a multi-step grinding cycle that alternately repeats the dressing operation, and the grinding wheel is machined while the operation switch operated by the operator is pressed. An internal grinding device comprising means for rapidly feeding the object forward toward the inner surface of the object, and means for starting the multi-step grinding cycle based on the position where the operation switch is released from the depression.