CN-122007977-A - Machine tool

Abstract

The invention provides a machine tool capable of precisely judging poor clamping. A machine tool (NC) 1 having a 1 st spindle (4) having a collet chuck (48) for gripping a rod-like raw material (W1), wherein a plurality of products of the same shape are manufactured by repeatedly performing a machining operation on the raw material (W1) gripped by the collet chuck (48), wherein a determination means (23) is provided, and wherein the determination means (23) determines whether the gripping of the 1 st spindle (4) is defective based on at least one of the information on the machining time point indicating the time point at which the machining operation is performed and the gripping force history information, which is the gripping force information when the collet chuck (48) gripped the raw material (W1) during the previous machining operation, and the current gripping force information, which is the gripping force information when the collet chuck (48) gripped the raw material (W1) during the current machining operation.

Inventors

• KAGAWA YUSUKE
• A man with a sickle and a plough
• IDENO MASATOSHI
• Hiroshima Saito

Assignees

• 星精密株式会社

Dates

Publication Date

20260512

Application Date

20251104

Priority Date

20241112

Claims (8)

1. 1. A machine tool having a spindle having a clamping portion for clamping a rod-shaped material, wherein a plurality of products having the same shape are manufactured by repeatedly performing a machining operation to machine the material clamped by the clamping portion, The machining apparatus includes a determination means for determining a defective grip of the spindle based on at least one of machining time point information indicating a time point at which the machining operation is performed and grip history information which is information of a grip force at which the material is gripped by the grip portion in the previous machining operation, and current grip force information which is information of a grip force at which the material is gripped by the grip portion in the current machining operation.
2. 2. The machine tool according to claim 1, wherein the determination means determines that the holding failure is caused by a preparation error when the holding force in the current holding force information is out of a predetermined range when the processing time point information is information indicating the initial processing operation.
3. 3. A machine tool according to claim 1, wherein a feeder is connected, which stores a plurality of the raw materials and sequentially feeds the stored raw materials to the spindle, The determination means determines that the material diameter failure of the material supplied by the feeder causes a gripping failure when the gripping force in the current gripping force information is out of a predetermined range when the processing time point information is information indicating the processing operation immediately after the feeder newly supplies the material to the spindle.
4. 4. The machine tool according to claim 1, wherein the determination element determines that the clamping failure is caused when an amount of change in the clamping force in the current clamping force information relative to the clamping force in the clamping force history information exceeds a threshold.
5. 5. The machine tool according to claim 4, wherein the determination element classifies the type of the clamping failure according to whether the clamping force in the current clamping force information increases or decreases with respect to the clamping force in the clamping force history information when the change amount exceeds the threshold value.
6. 6. The machine tool according to claim 4, comprising a control device that executes a removal operation for removing foreign matter entering the clamping portion when the change amount exceeds the threshold value and when the clamping force in the current clamping force information increases relative to the clamping force in the clamping force history information.
7. 7. The machine tool according to claim 1, wherein the determining means classifies the type of the clamping failure based on a combination of whether or not the clamping force in the current clamping force information is out of a predetermined range and whether or not a variation of the clamping force in the current clamping force information with respect to the clamping force in the clamping force history information exceeds a threshold value.
8. 8. The machine tool according to claim 1, comprising: a tool holder to which a tool for processing the raw material is attached and which moves together with the tool; A memory element for storing a movement correction value for correcting a specified movement position specified in the machining program, and A correction value rewriting unit that rewrites the movement correction value stored in the storage unit; The correction value rewriting unit rewrites the movement correction value stored in the storage unit when the determination unit determines that the holding force in the current holding force information is out of a predetermined range and the amount of change in the holding force in the current holding force information relative to the holding force in the holding force history information does not exceed a threshold value.

Description

Machine tool Technical Field The present invention relates to a machine tool for machining a material held by a spindle. Background A machine tool for machining a rod-shaped material held by a spindle is known (for example, refer to patent document 1). The spindle is rotatably supported by a spindle table. The main shaft is provided with a clamping part which can change state between a clamping state for clamping the raw material and a clamping releasing state for releasing the clamping of the raw material. Further, a safety monitoring system has been proposed in which a sensor is attached to a clamping portion to determine a clamping failure in the clamping portion (for example, refer to patent document 2). [ Prior Art literature ] [ Professional literature ] [ Professional document 1] Japanese patent application laid-open No. 2020-97075 [ Professional document 2] Japanese patent application laid-open No. 2011-121148 Disclosure of Invention [ Problem to be solved by the invention ] However, in the safety monitoring system of the patent document 2, since the abnormality determination is performed only by the output of the sensor attached to the clamping portion, there is a problem that the determination can be performed only in a unified manner, and it is difficult to precisely determine the defective clamping of the clamping portion. The present invention has been made in view of the above-described problems, and an object thereof is to provide a machine tool capable of precisely determining a clamping failure. [ Means of solving the problems ] The machine tool of the present invention which solves the problems described, A spindle having a clamping portion for clamping a rod-shaped raw material, and a plurality of products having the same shape are manufactured by repeatedly performing a machining operation to machine the raw material clamped by the clamping portion, The machine tool is provided with a judging element which judges whether the clamping failure of the main shaft is caused by the clamping force information which is at least one of the processing time point information indicating the processing operation and the clamping force history information which is the information of the clamping force when the clamping part clamps the raw material in the last processing operation, and the current clamping force information which is the information of the clamping force when the clamping part clamps the raw material in the current processing operation. According to this machine tool, the determination element performs determination of the clamping failure based on at least one of the machining time point information and the clamping force history information, and the current clamping force information, and therefore, the clamping failure can be precisely determined. Here, the machine tool may perform a plurality of cycles with the machining action of making 1 product as 1 cycle. The determination element may classify the type of the clamping failure to determine. The determination means may classify the defective grip for various reasons to determine the defective grip. In the machine tool, the machine tool comprises a machine tool body, The determination means may determine that a clamping failure has occurred due to a preparation error when the clamping force in the current clamping force information is out of a predetermined range when the processing time point information is information indicating the first processing operation. According to this machine tool, it is specified that the defective clamping force is caused by a preparation work error, and thus, it is easy to cope with the defect. In the machine tool, the machine tool comprises a machine tool body, A feeder connected to the main shaft for storing a plurality of raw materials and sequentially feeding the stored raw materials to the main shaft, The determination means may determine that the defective material diameter of the material supplied by the feeder causes defective gripping when the gripping force in the current gripping force information is out of a predetermined range when the processing time point information is information indicating the processing operation immediately after the feeder newly supplies the material to the spindle. According to this machine tool, since it is specified that the clamping force is poor due to the poor diameter of the raw material, it is easy to cope with the defect. In the machine tool, the machine tool comprises a machine tool body, The determination element may determine that the clamping failure is caused when an amount of change in the clamping force in the current clamping force information relative to the clamping force in the clamping force history information exceeds a threshold. Thus, for example, a case where a small foreign matter enters the nip portion can be determined as a defective nip. In addition, in the machine tool, The determination element may classify the type of the clamping