JPS5882652A - Spare tool replacing method in numerically controlled machine tool - Google Patents

Abstract

PURPOSE:To require no spare tool of the same shape and size as a standard tool and to require no special auxiliary unit by storing in memory the inherent tool correction data on all tools including spare tools respectively in a numerically controlled unit. CONSTITUTION:A machine tool control unit 2 is operated to control a machine tool by receiving the data of a numerically controlled paper tape 1a of a numerically controlled unit 1. Various programs for operating the machine tool is stored in the tape 1a, and designation of tools and correction of tool sizes have been programmed. A tool life monitoring unit 3 checks the usage time of tools after receiving a tool number signal S1 from the unit, and outputs a tool number signal S2, the unit 2 outputs a completion signal to the tool life monitoring unit 3, then the unit 1 reads out and executes the next block of the program after receiving a completion signal S4 from the unit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for changing a spare tool in a numerically controlled machine tool such as a machining center.

Recently, small-scale unmanned operation systems have been put into operation that are centered on machining centers and are equipped with workpiece supply devices for loading, unloading, and storing workpieces. This system often processes a wide variety of workpieces in small quantities, and due to the limited number of tools, consideration is given to allowing the same tool to be used for each workpiece, so the usage time of each tool can be managed. is complicated and not easy. For this reason, tool management devices have been developed that automatically manage usage time. This tool management device includes a spare tool exchange function that calculates the usage time of each tool and replaces the currently used tool with a spare tool when this accumulated time reaches a preset Q life. is normal.

Normally, numerical control devices that control machining centers come with a tool compensation function that corrects tool dimensions, but in the conventional tool compensation function, the assumed tool dimensions for each basic tool are programmed onto a paper tape. , to correct the dimensional difference between the assumed tool dimensions and the dimensions of the used tool. Therefore, when a tool reaches the end of its life and is replaced with a spare tool, the tool cover data used for this spare tool remains the same as the basic tool, so the spare tool must have the same shape and dimensions as the basic tool. It was practically unusable.

For this reason, conventional numerical control devices with a tool correction function can only be applied to specific tools, and in order to be applied regardless of the shape and dimensions of the spare tool, there are drawbacks such as the need for special attachment equipment. .

The purpose of this invention is to solve the above-mentioned conventional drawbacks and to provide a spare tool changing method in which correct tool correction is performed even if the spare tool is used for the entire time. In a machining center or the like that has a tool change function, a numerical control device stores unique tool compensation amount information for all tools including spare tools, and a means is provided to detect tool life or tool breakage and determine whether or not the tool can be used. When the tool management device has determined that the tool with the tool number specified by the numerical control device is unusable, the tool management device outputs a signal to the numerical control device, and this signal causes the numerical control device to reserve a spare tool. This allows the tool number to be specified and the unique tool compensation amount information for that spare tool to be valid, thereby ensuring that the correct tool compensation is performed for each spare tool as well. It is something.

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

Fig. 1 shows the configuration of the control unit of a machining center, and an F machine (not shown) equipped with an automatic tool changer has a numerical control paper tape (hereinafter referred to as No tape) of a numerical control device (hereinafter referred to as No device) 1. It is controlled by a machine tool control device 2 which operates in response to the information of (abbreviated) 11, and performs various operations such as machining and tool exchange. In addition, this machine tool is equipped with a tool storage magazine that can store, for example, about 20 to 60 tools, and an automatic tool changer can store N tools necessary for cutting from the tool storage magazine.
The o-tape is taken out based on the information on the tape and inserted into the main shaft of the machining center for use. In addition to cutting workpieces, this tool storage magazine automatically replaces the basic tools when they reach the end of their service life due to wear, or is damaged and becomes unusable. It has spare tools that can be retrieved and used. This spare tool is particularly required when the machining center is operated unattended for a long period of time.

Further, 3 is a tool life monitoring device, that is, a tool management device, which monitors whether the tool has reached the end of its life or is damaged and unusable.This tool life monitoring device 3 has a built-in memory. The machine is equipped with a tool table book as shown in Figure 2. This tool table 4 includes a tool number area 4a and a life time area where the allowable life time for each tool is set from an operation section (not shown) of the tool life monitoring device 8! b
%Usage time area 4 that stores the cumulative usage time up to now
0% Flag area indicating whether or not the tool can be used! 's and an in-use tool registration area 4e that stores the tool number of the tool currently in use. These memories are memories whose data contents do not change even if the power is turned off (such as core memory). is used.

Further, the NC tape 1a of the NO device 1 has various programs for operating the machine tool, and the designation of tools and correction of tool dimensions are programmed as shown in FIG. That is, T5i! If 11 is the tool number of the basic tool, the D code of each block of the basic tool ry51 and its spare tools Ty3z and Tφ3 contains tool correction amount information DyJ1, D9!52 unique to each tool.
, Dda3 is programmed. Furthermore, an end M code (for example, M21) is programmed at the end of the spare tool.

Further, a block skip code of 2 of the slash code (2), that is, /2, is programmed into the spare tool block and the end M code block, respectively. In FIG. 3, Tpl・'E'door 2Tg63. M
Each block for 21 is A1, A2, A3 respectively.
, shown in A4.

When the tool life monitoring device 3 receives the number signal S from the No. device 1 to the machine, it checks the usage time of the tool with that number using the usage time area 4b of the tool table 4, and determines if the tool has not yet reached its life time. When the abnormal tool is not registered and no abnormal tool is registered, a usable flag is set in the flag area 4a, and the tool number signal S□ is directly output to the machine tool control device 2 according to this flag. There is. The machine tool control device 2 has its tool number S2
The machine tool selects the estimated tool and inserts it into the spindle. After these operations are completed, a completion signal B1 is sent to the tool life monitoring device 3, and the tool life monitoring device 3 sends the No. device 1. The completion signal ζ is output to indicate that it is OK to move on to the operation of the next block of the program for NO tape 1&.
No device 1 receives this completion signal S4.
Reads the next block of the program by
It is set to be put into action.

Next, operations related to tool exchange, centering on the operations of the tool life monitoring device 3, will be explained in more detail based on the operation flowchart of the tool life monitoring device shown in FIG.

When a tool command based on a tool number signal etc. comes from the No. device 1, the tool life monitoring device 3 determines whether the signal is a tool command (Nl), and if it is a tool command, stores the tool number in the memory. Used tool registration area 4 of tool table 4
Store it in e (N2).

When the tool number is registered, the flag area 4a for that tool is used to determine whether or not the tool can be used.
), when it is determined that the tool can be used, outputs a /2 block no signal and outputs the tool number signal 82 of the tool to the machine tool control device 2 (N4).

Upon receiving this tool number signal S2, the machine tool control device 2 causes the machine tool to select a designated tool number tool from the tool delivery drum and replace it with the tool currently inserted into the spindle. This tool change is performed by an automatic tool change device attached to the machine tool.

When the tool exchange is completed, in response to the completion signal S3 issued from the machine tool control device 2, the completion signal B,
is output (N6). In the No. device 1, this completion signal 84
The program will not proceed to the next block unless it arrives.

That is, by controlling the completion signal, the processing progresses to the next numerical control operation block.

N if the basic tool (i.e. the tool not from the /code block) or its spare tool (i.e. the tool from the /code block) is available.

In the apparatus 1, the process A4 of the program shown in FIG. 3 is not read out. Therefore, the branch of determining whether there is a spare tool end M code (N7) proceeds to the next determining process of whether the in-use signal is ON (N8).

When the designated tool is inserted into the spindle and the numerical control operation progresses, a tool in use signal S is sent from the machine tool control device 2 to the tool life monitoring device 3.

As the tool-in-use signal, for example, an AND signal of a contact signal between the workpiece and the tool and a spindle rotation signal may be used. Subsequently, the tool in use signal S, 01
The time is counted by a timer, and every time a predetermined time elapses, the usage time area 4c for the tool number registered in the in-use tool registration area 4e is incremented in the tool table 4 (Ng to 110). Then, it is determined whether "lifetime - usage time≧0" (B111), and if the usage time exceeds the lifespan, the tool is registered as unusable in the 7 lag area 4d of the tool number (N12).

Even in this case, the machine tool will not be stopped immediately, but the item currently being machined will continue to be machined.
When the same tool is specified again, it is preferable to perform processing such as checking whether it is an invalid tool or not at the beginning of machining or not, and not restarting the process.

In addition, when the tool life monitoring device 3 determines that the commanded tool is unusable, the tool life monitoring device 3 sends a signal (/2 block presence signal) s6 indicating that the block marked with the block skip code of /2 is valid (/2 block presence signal) to the No device. 113), and
The sent tool number is not sent to the machine tool control device 2, and the completion signal s4 is returned to the No. device 1.

The specified tool that has been determined to be unusable is the basic tool (T5f).
ll), in No. 1, A
Block skip code for 2 blocks is also valid /2
Since the block presence signal S6 is output from the tool life monitoring device 8 to the No. device 1, the No. device 1 is
Read flat 2 block of $2D door 20B, T521z
A tool number signal (B1) is output to the tool life monitoring device 3. This tool life monitoring device 8 checks whether or not the tool can be used (Ny), and if it is determined that the tool can be used,
That tool number! 02 is sent to the machine tool control device 2 (N
4) At the same time, the D code (D1212) of the block with tool number Tda2 becomes valid in No. 1 device.

Note 7 is the position control signal of each axis of the machine tool and other N
o Indicates a control signal.

Note that before returning the tool change completion signal S4 for this T5212 tool to the No. device 1, the block skip signal B of the A2 block is invalidated and the next block (blocks A3 and A4 of the program in Fig. 5) is executed. is invalidated, and then the completion signal S4 is returned to the No device 1. Therefore, the programs in blocks Jl and Am are ignored and N
O tape operation continues.

Furthermore, when it is determined that both the basic tool and all spare tools are unusable, the block M4 of the program shown in Figure 3 is read, and the signal S of the spare tool end M code (A21 in the example) is sent to the No device. 1 and receives this signal, the tool life monitoring device 3 branches at the judgment N7 in FIG. 4, displays an abnormality display, and outputs a signal indicating that there is no spare tool (
N15).

This N15 processing does not necessarily require any specific processing, but it usually involves lighting up an indicator lamp,
Issue a warning to workers or supervisors by temporarily stopping the machine tool.

In the method of the above-described embodiment, the structure is such that only a specific block skip function is used and this function is enabled or disabled, so the means for informing the IC device 1 of the correction amount of the spare tool is very inexpensive. It has been realized. In addition, since the method of inputting the correction amount for the spare tool is the same as the operation of the normal No. device, there is less burden on the operator to obtain the correction amount for each tool. Furthermore, since the program can arbitrarily select the number of spare tools and tool numbers, programming does not become complicated.

As explained above, according to the present invention, it is possible to perform numerical control machining by obtaining unique tool correction information for all tools, including spare tools, so that the basic tool and its spare tools can be It is not necessary to have the same shape and dimensions,
Further, there is no need to use special accessory equipment, and furthermore, there is no inconvenience that the tool can only be applied to a specific tool, and spare tools can be replaced easily and efficiently.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention. Figure 1 is a configuration diagram of the control section of a machining center, Figure 2 is a tool table diagram in the memory built into the tool life monitoring device, and Figure 2 is a diagram of the tool table in the memory built in the tool life monitoring device. FIG. 4, which is an explanatory diagram of a part of the program, is an operation flowchart of the tool life monitoring device. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A tool management device that stores unique tool compensation amount information for all tools, including spare tools, in the numerical control device, and has a means for detecting tool life or tool breakage and determining whether or not the tool can be used is transferred from the numerical control device. When it is determined that the tool with the designated tool number is unusable, the tool management device outputs a signal to the numerical control device, and this signal causes the numerical control device to specify the tool number of the spare tool, and A method for changing a spare tool in a numerically controlled machine tool, characterized in that information on the amount of tool correction unique to the spare tool is made effective.