JPS61238425A - Setting method for nibbling pitch in press machine - Google Patents

Abstract

PURPOSE:To obtain safely and with high accuracy the necessary circular to by processing in use of the optimal nibbling pitch found by the operation with the maximum allowance value calculated from the capacity, etc. of the press machine as the standard. CONSTITUTION:The maximum allowable pitch dmax is first calculated from the data of the number os strokes of the punching pess, the length of all dies, the maximum plate thickness of the work, etc. when the nibbling start command is inputted. The inputting nibbling pitch Q which is set by the distance on the circular arc to be nibbled taking into consideration the residual quantity on the nibbling face and processing time is then read and the Q and dmax are com pared. The optimal value of the nibbling pitch angle that the circular arc can ripple to the end is found by progressing to the following step in case of Q< dmax. By processing under the conditions found as above the necessary circular arc is obtainable safely and with high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for setting a nibbling pitch in a press machine.

[Conventional technology]

When performing nibbling on the circular arc of the workpiece W by continuous operation of an NG turret punch press machine, for example, as shown in Fig. 4, the workpiece W is moved relative to the mold in response to the continuous punching operation of the mold. Move the work piece W little by little.
The trajectory of the upper mold is along arc A at T+, T2, T3
・・・・・・Make it move as Tn.

At this time, the press ram that presses the mold and the shaft that supports the workpiece W are driven in mutually timed manner as shown in FIG. 5, which is a time chart of the press operation and shaft movement. That is, as shown in the time chart at the top of Figure M4, the press ram reciprocates between the top dead center and the bottom dead center, and performs nibbling between the interference point and the bottom dead center (i.e., during time domain B). In order to perform this, the mold is caused to interfere with the workpiece W, and the mold is caused to interfere with the workpiece W between the interference point and the top dead center (i.e., during time domain A).
I'm trying to extract it from. Then, the shaft supporting the workpiece W is driven to move the workpiece W during the time domain A, for example, as shown in the speed curve a or speed curve 2 in the lower part of FIG. At that time, if the shaft supporting the mold is driven while the mold is interfering with the workpiece W, as shown in the speed curve C, it may damage the workpiece W or even prevent the desired processing from occurring. A problem arises in that accuracy cannot be achieved.

Therefore, input data,
For example, the nibbling pitch is set to X. In addition, the fourth
Since the time chart at the bottom of the figure shows the "velocity" of the axis movement, the "distance" of the axis movement is the integral of each speed curve a, b, and c (that is, the speed curve a, b, or C and the time axis). area of the enclosed triangle). Therefore, the maximum material movement distance that the workpiece W can move while the press ram reciprocates in one cycle is the value expressed by the integral of the maximum material movement speed curve (hereinafter, this maximum material movement distance is defined as the maximum allowable pitch). (abbreviated as dn+ax). Now,
Conventionally, when performing nibbling on the arc A, the actual nibbling pitch was set as follows. That is, the sixth
As shown in the figure, first, the nibbling pitch Q (
The input nibbling pitch (hereinafter abbreviated as "input nibbling pitch") is set to a value that is sufficiently small so that the amount of remaining material on the nibbling surface is equal to or less than a predetermined value, and sufficiently large that the working time is sufficiently shortened. Next, this person's nibbling pitch Q is compared with the maximum allowable pitch dmax, and the input nibbling pitch Q is
If the pitch exceeds the maximum allowable pitch dmax, a program error is displayed and the nibbling operation is interrupted. On the other hand, the input nibbling pitch Q is the maximum allowable pitch dmax
If it is below, for example, as shown in FIG. 6, the corresponding pitch angle θ is calculated from the set nibbling pitch Q, and the distance d between the centers of adjacent mold trajectories is calculated. During one cycle of the press ram, the workpiece W is moved by this distance d, and as shown in FIG. 4, nibbling is performed on the arc A at a nibbling pitch d.

However, in this method of setting the nibbling pitch, the actual nibbling pitch d is always slightly longer than the input nibbling pitch Q.

Therefore, if the input nibbling pitch Q approaches the maximum allowable pitch dmax in an attempt to reduce the machining time to the minimum, the input nibbling pitch Q becomes the maximum allowable pitch dmax.
Although it is set smaller, the actual nibbling pitch d exceeds the maximum allowable pitch dlax, and therefore the workpiece W is driven while the die is interfering with the workpiece W, resulting in damage to the workpiece W or failure to achieve the desired machining accuracy. There was a problem that sometimes it did not appear.

As a method to solve this problem, it is possible to use the actual nibbling pitch d itself instead of the pitch Q on the arc A as the input nibbling pitch input to the nibbling processing program. In this case, if data is input so that the actual nibbling pitch d is equal to or less than the maximum allowable pitch dmax, there is no risk of damage to the workpiece. However, this method is inconvenient because it is not easy to predict the amount of remaining material on the nibbling surface. or,
When the input nibbling pitch is kept constant and the mold diameter is changed, the remaining amount of the nibbling surface is the arc A described above.
In the former method of specifying the input nibbling pitch Q above, as shown in FIG. 7, although it does not change much, just changing from Sl to 82, the latter method uses the actual nibbling pitch itself as the input nibbling pitch. In this method, as shown in FIG. 8, there is a large change from S-+ to S-2. Therefore, in the latter method, there is a problem in that it is very difficult to select the nibbling pitch and mold when trying to make the nibbling surface constant.

[Object of the Invention] An object of the present invention is to solve the problems of the conventional nibbling pitch setting method, and to set the input nibbling pitch Q, which is specified by the distance on the arc to be nibbled, to a value extremely close to the maximum allowable pitch dmax. A method for setting the nibbling pitch in a press machine that allows high-precision nibbling along a desired arc without damaging the workpiece even if the mold diameter is variously changed under these conditions. The goal is to provide the following.

[Summary of the invention]

In order to achieve the above-mentioned object, the method for setting the nibbling pitch in a press machine of the present invention is such that when a predetermined length on the arc to be nibbled is input as the input nibbling pitch, the arc is set at an actual nibbling pitch different from the input nibbling pitch. The actual nibbling pitch specified by the nibbling processing program for nibbling is calculated in advance, and the maximum material movement distance that can be executed during one reciprocating movement of the press ram during nibbling operation is calculated. Calculate from the maximum material movement speed curve that is possible during one reciprocating motion, and compare the calculated actual nibbling pitch with the calculated maximum material movement distance, and if the actual nibbling pitch exceeds the maximum material movement distance. In this case, the actual nibbling pitch is set to a predetermined value less than or equal to the maximum material movement distance, and the arc is nibbled.

(Embodiment) Hereinafter, a case where an embodiment of the present invention is applied to an NC turret punch press to nibble a workpiece along a predetermined circular arc will be described with reference to FIGS. 1 to 3.

Fig. 1 is an explanatory diagram of the input data input in this embodiment, Fig. 2 is a processing flowchart showing the execution of this embodiment, and Fig. 3 shows the pitch angle θ to be input into the conventionally well-known nibbling processing program. FIG. 3 is an explanatory diagram showing the relationship with the actual nibbling pitch d.

In this example, the radius I, as shown in FIG.

It is assumed that a circular arc A having a machining angle K is nibbled at a cannibling pitch Q from a machining start position angle J using a mold having a mold diameter p. Here, the mold diameter p is set as a positive value (i.e. +1=lpl) when nibbling the outside of the arc A, and as a negative value (i.e. +1=lpl) when nibbling the inside of the arc A. , p=-lpl
).

Now, in Fig. 2, when a nibbling start command is input at step 101, first, at step 102, based on data such as the number of press strokes of the turret punch press, the length of the mold, and the maximum thickness of the workpiece, Maximum allowable pitch dm
Calculate ax.

Next, in step 103, an input nibbling pitch Q is read out, which is set at a distance on the arc to be nibbled, taking into account the amount left on the nibbling surface and the machining time, and this input nibbling pitch Q is set by the maximum allowable pitch dmax.
Compare with. If this input nibbling pitch Q is larger than the maximum allowable pitch dmax, a program error is displayed in step 104, and the operation is ended in step 105. In this case, the input nibbling pitch Q is reset and the operation is restarted from step 101.

On the other hand, if the input nibbling pitch Q is smaller than the maximum allowable pitch dmaX in step 103, step 10
6, the nibbling length L = 2πI x (K/360) is calculated from the radius I of the arc A and the machining angle K, and in step 107, this nibbling length is divided by the input nibbling pitch Q, and the temporary nibbling number N is calculated. and calculate the remainder S. Then, in step 108, it is determined whether the remainder S is zero or not. If it is not zero, it means that the arc A is not nibbled to the end, so step 1
At step 09, the temporary nibbling number N is increased by one in order to nibble the arc A to the end. Once the nibbling number N that allows arc A to be nibbled to the end is thus determined, the nibbling length is divided by the nibbling number N in step 110 to calculate the nibbling pitch angle θ.

Next, in Step 4 knob 111, it is determined whether or not the diameter p of the mold used is negative, that is, whether or not to nibble the inside of the circular arc A. If the mold diameter p is negative, that is, the inside is nibbled. In this case, the actual nibbling pitch is the maximum permissible pitch dm
Since it is even smaller than the nibbling pitch Q on the arc A, which is smaller than ax, the following actual nibbling pitch correction procedure is omitted and step 114 is hejjumped.
The nibbling operation is performed N times along the circular arc at the nibbling pitch angle θ determined in step 10.

However, when the mold diameter p is positive in step 111, that is, when nibbling outside the arc A, even if the input nibbling pitch Q is smaller than the maximum allowable pitch dmax, the nibbling pitch angle θ determined in step 110 is The actual nibbling pitch d (see FIG. 3) corresponding to may be larger than the maximum permissible pitch dlaX. Therefore, in step 112, the actual nibbling pitch d is calculated from the nibbling pitch angle θ, and in step 11
3, this actual nibbling pitch d is the maximum allowable pitch di
It is determined whether or not it exceeds aX. If the actual nibbling pitch d exceeds the maximum allowable pitch dmax, the process jumps to step 115 and starts the actual nibbling pitch correction procedure described below.

That is, in step 115, after setting the actual nibbling pitch d to the maximum allowable pitch dmax, the step 1
A computation opposite to the computation executed in step 12 is executed to calculate the nibbling pitch angle θ at which the actual nibbling pitch d should be set to dmax.

In step 116, the nibbling angle K is divided by the corrected nibbling pitch angle θ to calculate the corrected temporary nibbling number N and remainder S.

Then, in step 117, the remainder S is determined, and if the remainder S is not zero, the provisional nibbling number N is increased by one time in step 118, and in step 119, the nibbling angle K is renewed with this increased nibbling number N. to determine the final nibbling pitch angle θ. Note that since the final pitch angle θ determined in step 119 is always smaller than the pitch angle θ calculated in step 115, the actual nibbling pitch d corresponding to the final pitch angle θ shown in FIG. 3 is always smaller than the maximum allowable pitch dmaχ. This enables safe and accurate nibbling.

In this way, when the final nibbling pitch angle θ and the number of nibbling operations N are determined, in step 114, the arc A is nibbled at the final nibbling pitch angle θ and the final number of nibbling operations N, and in step 120, the predetermined nibbling operation is completed. do.

Therefore, according to the nibbling pitch setting method of this embodiment, the input nibbling pitch Q
Even if d is specified, the actual nibbling pitch d is always less than or equal to the maximum allowable pitch dllaX, so it is possible to nibble arcs safely and with high precision.

In the above embodiment, if the actual nibbling pitch d is larger than the maximum allowable pitch dmax in step 113, the nibbling pitch angle θ is changed in step 115 so that the actual nibbling pitch d is equal to the maximum allowable pitch dIIlax. However, it is not necessary to do so, and the nibbling pitch angle θ may be set so that the actual nibbling pitch is a value slightly smaller than the maximum allowable pitch dmax.

Furthermore, if the input nibbling pitch Q commanded on the arc A in step 103 is larger than the maximum allowable pitch dmax, the step 104 jumps and a program error is output.
5, and the nibbling process may be performed by setting the nibbling pitch angle θ so that the actual nibbling pitch d is equal to the maximum allowable pitch dmax.

Furthermore, in the embodiments described above, the mold for performing the nibbling process has a circular cross section, but it goes without saying that the mold may have a rectangular cross section or the like.

〔Effect of the invention〕

The nibbling pitch setting method for the press machine of the present invention is configured as described above, and the nibbling pitch specified on the arc is set to a value extremely close to the maximum allowable nibbling pitch in order to shorten the machining time. Even if the molds are changed, the actual nibbling pitch will not exceed the maximum allowable pitch in the press machine, so a desired circular arc can be nibbled safely and with high precision.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of input data input in an embodiment of the present invention, FIG. 2 is a processing flowchart showing the processing of this embodiment, and FIG. 3 is a diagram showing the relationship between the nibbling pitch angle θ and the actual nibbling pitch d. 4 is an explanatory diagram showing the relationship between the press ram and the workpiece during the nibbling process. 6 is an explanatory diagram showing the relationship between the input crabbing jig pitch Q and the actual nibbling pitch d in the conventional actual nibbling pitch setting method, and FIG. Figure 8 is an explanatory diagram showing the variation in the amount left on the nibbling surface that occurs when the mold is changed while keeping the nibbling pitch specified by the distance on the arc to be nibbled constant. FIG. 4 is an explanatory diagram showing a change in the amount of remaining material on the nibbling surface that occurs when the mold is changed. Figure 1 Δ Figure 4 Figure 5 Figure 6 Figure 7 τ2 T+ Figure 8

Claims (1)

[Claims] When a predetermined length on the arc to be nibbled is input as the input nibbling pitch, the actual nibbling pitch specified by the nibbling processing program that nibbles the arc at an actual nibbling pitch different from the nibbling pitch is calculated in advance, and at the time of nibbling operation. The maximum material movement distance that can be executed during one reciprocating movement of the press ram is calculated from the maximum material movement speed curve that the press machine can perform during one reciprocating movement of the press ram, and the calculated actual nibbling distance is The pitch is compared with the calculated maximum material movement distance, and if the actual nibbling pitch exceeds the maximum material movement distance, the actual nibbling pitch is set to a predetermined value less than or equal to the maximum material movement distance, and the arc is A method for setting a nibbling pitch in a press machine, characterized in that the nibbling process is performed.