JPS62107972A - Grinding machine - Google Patents

Abstract

PURPOSE:To select correction of a grindstone at a proper timing, by a method wherein the propriety of a previously set grinding pattern is decided by effecting determination from a marging prevailing when actual grinding takes place, and when the pattern is improper, a grinding pattern is changed to a futher proper pattern. CONSTITUTION:At least three different grinding patterns of a general grindstone correction cycle, wherein, after rough feed and finish feed are conducted, a grindstone is corrected, an intermediate grindstone correction cycle, wherein a grindstone is corrected one time in the middle between rough feed and finish feed, and a plural grindstone corrections cycle, wherein a grindstone is corrected plural times in the middle between rough feed and finish feed, are set by a set means 19. When the margin of a work detected by a detecting means is not within a margin range determined by a setting means 20, a fundamental pattern, set by a setting means, is changed by a grinding pattern changing means (marging deciding circuit) 18 according to the size of the margin, and an optimum grinding pattern is automatically selected according to the margin of a work being a fundamental most amount of grindstone correction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a grinding machine that processes a workpiece using a grindstone;
In particular, the present invention relates to a grinding machine equipped with a grindstone correction device for correcting a grindstone using a correction tool such as a dressing diamond.

[Prior art] Generally, when grinding a workpiece using a grinding machine,
A grinding pattern in which, for some workpieces, the grinding wheel is corrected after rough feed (rough machining) and finish feed (finish machining) have been performed, and for other workpieces, the grinding wheel is corrected once between the rough feed and finish feed. and for the same work,
All grinding processes are performed using the same grinding pattern.

However, even though the workpieces are the same, there are dimensional errors in the workpieces to be machined, and the machining allowance for a certain lot of workpieces becomes considerably large, making it difficult to correct the grinding wheel using the originally set grinding pattern. There is a problem that the process cannot be performed effectively and the desired machining accuracy cannot be obtained.

Furthermore, if the machining allowance is smaller than the expected machining allowance, the grinding wheel will be corrected at a timing when it is not necessary, reducing machining efficiency and causing excessive correction of the grinding wheel.

[Object of the Invention] The object of the present invention is to provide a grinding machine that focuses on the machining allowance of a workpiece, which is the most basic data for grinding wheel correction, and can set an optimal grinding pattern according to the detected machining allowance. It is.

[Configuration of the Invention] For this reason, the inventor of the present invention set a basic grinding pattern according to the type of workpiece to be machined, and at the same time detected the machining allowance during or after machining, and If the machining allowance is not within the machining allowance range set when setting the basic grinding pattern, the grinding pattern is changed according to the detected deviation of the machining allowance amount.

[Effects of the Invention] According to the present invention, the optimum grinding pattern is automatically selected according to the machining allowance of the workpiece, which is the most basic amount of grinding wheel correction, so it is possible to optimize the timing of grinding wheel correction. It is possible to maintain machining accuracy and improve machining efficiency.

[Embodiments] Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings.

As shown in Figure 1, the overall system configuration is as follows:
'A main spindle 2 that chucks the work l, a cutting table 3 that feeds the work l, a machining head 6 with a grindstone 4 replaceably attached to the tip of the whetstone spindle 5, and a machining head 6 that rotates the machining head 6 in the axial direction. A grindstone table 7 that moves forward and backward, and a dress diamond 8
The basic component is a dressing device 9 for dressing the grindstone 4.

The cutting motor IO that feeds the cutting table 3 and the grindstone table 7 are controlled by a grinding machine control device 11 that controls the entire grinding machine.

This grinding machine control device! In addition to the optimum setting of the grinding pattern, which is the subject of the present invention, the grinding wheel 1 controls the cutting speed in accordance with the set grinding pattern, controls the position of the grindstone table 7, controls the dressing process, etc. The method of setting the grinding pattern will be described in detail below.

As shown in FIG. 1, the grinding machine includes a pre-gauge 12 for measuring the inner diameter of the workpiece 1 before machining, and an improv gauge 13 for measuring the inner diameter of the workpiece 1 during machining. Improv game! The output of 3 is sent to the machining allowance calculation circuit via the gauge amplifier 14! 5 is input.

This machining allowance calculation circuit 15 is selectively connected to the gauge amplifier 14 and a gap elimination device 16 provided for the machining head 6 via a changeover switch 17. When the gap elimination device 16 detects that the contact has come into contact with the work l and outputs a contact signal to the displacement calculation circuit 15, the changeover switch 17 is switched to the gauge amplifier i4 side, and first, the pre-gauge 12 detects the contact signal. Read the inner diameter D (D) of the workpiece 1 before machining, then read the inner diameter d (D) of the workpiece 1 detected by the improv gauge 13, and calculate the machining allowance △D (D=
D(D - d(D) is calculated, and the machining allowance ΔD(D) is input to the machining allowance determining circuit 18.

This machining allowance determination circuit 18 uses the following grinding pattern (
It is determined whether the detected machining allowance falls within the machining allowance range set in relation to the dress cycle).

(1) Setting the grinding pattern The grinding pattern determines the time, cutting speed, and dressing timing. In this example, as shown in Fig. 1, the grinding pattern is expressed by a total of four types of dressing cycles. Set.

(a) General dress cycle As shown in Figure 3 (a), this general dress cycle involves performing one dressing prior to cutting, then rough feed (a), finish feed (b), and grinding wheel. This is the most common cycle in which spark outs (c) are performed sequentially for withdrawal.

(b) Intermediate dress cycle As shown in Figure 3 (b), this intermediate dress cycle involves first performing rough feed (a), then performing one dressing, and after this dressing, finishing feed (rotation). ) and spark out (c), and is selected when the machining allowance is large or when the requirements for surface roughness after machining are severe.

(c) Multiple dressing cycle This multiple dressing cycle is selected when the machining amount is large, as shown in Fig. 3(c), and the dressing is performed after the -th rough feed (E ■). This is a dressing cycle in which dressing is performed multiple times between rough feeding and finishing feeding (b), such as performing the second rough feeding (E2) and then performing dressing again.

(d) Rework cycle In this rework dress cycle, as shown in Figure 3 (d), the original machining allowance is small, so it is not necessarily necessary to perform dressing for each machining process, and any number of machining operations can be performed. After the ceremony, the dress was done.

Such a grinding pattern can be set by specifying time, cutting position, and dress timing using a pattern setting means 19 such as a keyboard attached to the grinding machine control device 11.

(II) Setting the machining allowance range The machining allowance range is set for each of the above-mentioned dressing cycles.

An example of the settings is as follows.

(a) - Acid dress cycle 100μ Tribute≦∆D (D≦120μ Shoulder (b) Intermediate dress cycle 120μ then ∆D (D≦150μ1) (c) Multiple dress cycles ∆D (j) > 150μ Shoulder (d) Rework dress cycle ∆D (j) < 100μ Shoulder In addition, in a multiple dressing cycle, the machining range may be set in multiple stages depending on the number of dressings, and similarly, in a rework dressing cycle, how many times should one dress be performed? It is also possible to set the machining allowance range in multiple stages according to the number of skips indicated.

The machining allowance range can be set by the machining allowance range setting means 20.

(III) Grinding pattern setting and machining allowance determination When grinding a workpiece, first select one of the four types of grinding patterns mentioned above depending on the type of workpiece (size of machining allowance, required degree of surface roughness of the machined surface). One is preset.

Then, the grinding machine control device 11 executes grinding of the workpiece according to the set grinding pattern.

When one grinding process is completed, machining allowance determination is performed.

As shown in Fig. 2, this machining allowance determination is performed by comparing the machining allowance ΔD (D) measured at the end of the grinding process with the set machining allowance range. , it is determined whether the measured machining allowance ΔD(j) is within the range.

In the above example, if the intermediate dressing cycle is selected, for example, if the workpiece is of the same type as 120 μl and ΔD (05150 μm), the machining allowance is determined so that the next grinding is performed without changing the grinding pattern. The circuit 18 instructs the grinding machine controller 11 to make no changes.

Machining allowance ΔD (If D is not within the machining allowance range, instruct to change the next grinding pattern as follows.

Now, in the same way as above, if the intermediate dressing cycle is selected and the machining allowance ΔD(j) is below the machining allowance range (
If ΔD (D<120 μll), the machining allowance determination circuit 18 instructs to change the next grinding pattern to a general dress cycle.

Also, if the machining allowance exceeds the machining allowance range (ΔD(j)>15
0μ, the amount of removal is large, so an instruction is issued to the grinding machine control device 11 to change the next grinding pattern to a multiple dress cycle.

As is clear from the above example, the machining allowance determination circuit 18 determines whether the actual machining allowance falls within the machining allowance range set for each grinding pattern, and if it is not within the machining allowance range,
Instructs to change the grinding pattern depending on whether the machining allowance is below or above the machining allowance range.

The grinding machine control device 11 waits for the determination result by the machining allowance determination circuit 18, sets the next grinding pattern, and controls the cutting control motor 10, the grindstone table 7, and the dressing according to the set grinding pattern. Executes control over the device 9.

In the above embodiments, a total of four types of dressing cycles were illustrated, but the present invention is not limited to these. For example, in the -acid dressing cycle, dressing is performed after processing, or in which processing is performed several times in succession. , it is also possible to set the cycle to include one dressing cycle before or after that.

Further, in the above embodiment, the control system is shown as a hardware configuration, but it goes without saying that the automatic setting of the grinding pattern may be configured as a control software configuration using a computer and a program.

As described above, in the present invention, it is determined whether the preset grinding pattern is appropriate based on the machining allowance when actually grinding is performed, and if it is inappropriate, the grinding pattern is changed to a more appropriate one. The pattern will be changed.

For this reason, the dressing of the grindstone is carried out at appropriate timing without excess or deficiency, and by appropriate management of the grindstone, it is possible to improve machining accuracy and machining efficiency.

[Brief explanation of drawings]

FIG. 1 is a system configuration diagram of a grinding machine according to an embodiment of the present invention, FIG. 2 is a flowchart showing a flowchart for determining the suitability of a grinding pattern, and FIGS. 3(a) and (b). (c) and (d) are graphs each showing an example of a grinding pattern (dress cycle). 1... Workpiece, 3... Cutting table, 4...
- Grinding wheel 5... Grinding wheel axis, 7... Grinding wheel table, 9... Dressing device, IO... Cut feed motor, 11... Grinding machine control device, 12... Pre-gauge, 13... - Impro gauge, 15...Machining allowance calculation circuit, 18...Machining allowance determination circuit, 19...Pattern setting means, 20...Machining allowance range setting means. Patent applicant: Mazda Motor Corporation Representative: Patent attorney: Aohaku Ao and 2 others Figure 2

Claims (1)

[Claims] (1) In a grinding machine equipped with a grinding wheel at the tip of the grinding wheel shaft and a grinding wheel correction device that corrects the grinding wheel using a correction tool, there is a general grinding wheel correction cycle in which the grinding wheel is corrected after rough feed and finishing feed, and a rough grinding wheel correction cycle. At least three types of grinding patterns are set: an intermediate grinding wheel correction cycle in which the grinding wheel is corrected once between the feed and finishing feed, and a multiple grinding wheel correction cycle in which the grinding wheel is corrected multiple times between the rough feed and the finishing feed. basic pattern setting means for setting one of the grinding patterns according to the type of workpiece to be machined, and workpiece machining allowance detection means for measuring the dimensions of the workpiece to be machined and detecting the machining allowance. and a machining allowance range setting means for setting a machining allowance range corresponding to a basic pattern set according to the type of workpiece to be machined; A grinding machine characterized by being provided with a grinding pattern changing means for changing the basic pattern according to the size of the allowance.