JP7035150B1 - Machine Tools - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool for preventing damage to a tip portion of a spindle unit and occurrence of machining defects due to a programming error or an operation error when arranging a support portion on the tip side of a drill at a machining start position. SOLUTION: A contact detecting means for detecting contact of a drill tip side support portion 2 with a work 30 when the drill tip side support portion 2 is arranged at a machining start position, and a drill tip after the contact. It has a movement amount detecting means for detecting the movement amount of the side support portion 2 toward the base end side in the drill axial direction, and a movement amount determining means for determining whether or not the movement amount detected by the movement amount detecting means is appropriate. Machine Tools. [Selection diagram] Fig. 1

Description

The present invention relates to a machine tool for drilling.

As a machine tool for drilling, there is a gun drill machine as shown in Patent Document 1, for example, as a machine tool particularly suitable for deep hole drilling.

Before starting machining, this gun drill machine brings the drill tip side support part (guide bush) that rotatably supports the tip side of the gun drill to the work, and pushes the drill tip side support part to the work at a certain level. It is arranged at a position where it is pressed by force (machining start position), and machining is performed with this drill tip side support portion pressed against the work. Conventionally, this drill tip side support portion The placement operation at the machining start position is performed by automatic control by a program or manual operation by an operator.

Japanese Patent No. 6739587

By the way, in the conventional device, when a programming error or an operation error occurs in the disposition operation of the drill tip side support portion at the machining start position, the drill tip side support portion is pushed more than a specified value and a load is applied to the tip portion of the spindle unit. The drill tip side support and tip box provided at the tip of this spindle unit may be damaged, or machining may start and machining defects may occur when the drill tip side support is not in the proper machining start position. There is a risk of

The present invention has been made in view of the current state of the conventional apparatus, and even if a programming error or an operation error occurs, the support portion on the drill tip side can be prevented from being pushed more than specified, or the drill tip side can be prevented. It is an object of the present invention to provide a machine tool that prevents the start of machining in a state where the support portion is in an improper machining start position, and prevents damage to the tip of the spindle unit and occurrence of machining defects due to programming mistakes and operation mistakes. ..

The gist of the present invention will be described with reference to the accompanying drawings.

A drill tip side support portion 2 that rotatably supports the tip end side of the drill 20 provided on the spindle head 1 and comes into contact with the work 30 during machining is provided, and the drill tip side support portion 2 is provided in the drill axial direction by a pressurized fluid. A machine tool for drilling that is urged to the tip side and is configured to move to the base end side in the drill axial direction against the urging by abutting with the work 30, and is a machine tool for drilling. A contact detecting means for detecting the contact between the side support portion 2 and the work 30, and a movement amount detection for detecting the amount of movement of the drill tip side support portion 2 to the base end side in the drill axial direction after the contact. The present invention relates to a machine tool having a means and a movement amount determining means for determining whether or not the movement amount detected by the movement amount detecting means is appropriate.

Further, in the machine tool according to claim 1, the contact detecting means includes a flow sensor 3, and the drill tip side support portion 2 has a drill shaft due to contact between the drill tip side support portion 2 and the work 30. The flow sensor 3 detects the flow of the pressurized fluid due to the movement to the base end side of the direction, thereby detecting the contact between the support portion 2 on the tip side of the drill and the work 30. It relates to a machine tool characterized by the above.

Further, in the machine tool according to any one of claims 1 and 2, the movement amount detecting means is the movement amount of the work 30 toward the base end side in the drill axial direction, or the spindle head 1 and the drill tip side. The present invention relates to a machine tool characterized in that it is configured to detect based on the amount of movement of the spindle unit 10 provided with the support portion 2 toward the tip end side in the drill axis direction.

Further, in the machine tool according to any one of claims 1 to 3, the movement amount determining means has a movement amount of the drill tip side support portion 2 toward the base end side in the drill axial direction after the contact. The present invention relates to a machine tool characterized in that it is configured to output a signal for stopping the movement of the drill tip side support portion 2 when the amount exceeds a certain amount.

Further, in the machine tool according to any one of claims 1 to 4, when the distance between the drill tip side support portion 2 and the work 30 becomes a predetermined distance, the drill tip side support portion 2 and the work. The present invention relates to a machine tool, which is provided with an approaching movement speed decelerating means for reducing the approaching movement speed with 30.

Further, in the machine tool according to claim 5, the approach moving speed decelerating means has a measuring unit 4 for measuring the separation interval between the drill tip side support portion 2 and the work 30, and the measuring unit 4 measures the distance. The present invention relates to a machine tool, which is configured to reduce the approaching movement speed when the separation interval reaches a predetermined value.

Further, a drill tip side support portion 2 that rotatably supports the tip end side of the drill 20 provided on the spindle head 1 and comes into contact with the work 30 during machining is provided, and the drill tip side support portion 2 is drilled by a pressurized fluid. A machine tool for drilling that is urged toward the tip end side in the axial direction and is configured to move toward the base end side in the drill axial direction against the urging by abutting against the work 30. It has a measuring unit 4 that measures the separation interval between the drill tip side support portion 2 and the work 30, and when the separation interval measured by the measuring unit 4 reaches a predetermined interval, the drill tip side support portion 2 The present invention relates to a machine tool provided with an approaching movement speed decelerating means for reducing the approaching movement speed of the work 30 and the work 30.

Since the present invention is configured as described above, it is a machine tool that prevents damage to the tip of the spindle unit and occurrence of machining defects due to programming mistakes and operation mistakes.

It is explanatory schematic diagram which shows this Example. It is a processing state explanatory cross-sectional view which shows the processing state (before the start of processing) of this Example. It is a processing state explanatory sectional drawing which shows the processing state (at the time of deceleration switching) of this Example. It is a processing state explanatory cross-sectional view which shows the processing state (at the time of work contact) of this Example. It is a processing state explanatory cross-sectional view which shows the use state (drill tip side support part pushed state) of this Example. It is explanatory drawing which shows the appropriate range of pushing a support part on a drill tip side of this Example. It is a processing state explanatory cross-sectional view which shows the use state (during drilling process) of this Example. It is a flowchart which shows the processing procedure of this Example. It is a flowchart which shows the processing procedure of this Example. It is a flowchart which shows the processing procedure of another example (for manual operation) of this Example. It is a flowchart which shows the processing procedure of another example (for manual operation) of this Example.

An embodiment of the present invention which is considered to be suitable will be briefly described by showing the operation of the present invention based on the drawings.

For example, when arranging the drill tip side support portion 2 at the machining start position, when the drill tip side support portion 2 approaches and abuts on the work 30 due to the movement of the drill tip side support portion 2 or the work 30, the drill tip side The contact of the support portion 2 with the work 30 is detected by the contact detecting means.

After the drill tip side support portion 2 comes into contact with the work 30, the pressure fluid that urges the drill tip side support portion 2 toward the tip side in the drill axial direction by the movement of the drill tip side support portion 2 or the work 30. It moves (pushed) toward the base end side in the drill axial direction against the urging, and the drill tip side support portion 2 is arranged at the machining start position.

At this time, the amount of movement (pushing amount) of the support portion 2 on the drill tip side toward the base end side in the drill axial direction after the contact with the work 30 was detected by the movement amount detecting means, and was detected by the moving amount detecting means. Whether or not the movement amount (pushing amount) of the drill tip side support portion 2 is within the specified value is determined by the movement amount determination means, and if it is within the specified value, the drill tip side support portion 2 is in the proper machining start position state. Judging that it has become, the drilling process is started. Further, if the amount of movement (pushing amount) of the support portion 2 on the tip side of the drill is out of the specified value, the drilling process is not started, and for example, an alarm is output to notify the operator of the abnormality.

As a result, it is possible to prevent the drilling process from being started in a state where the drill tip side support portion 2 is not in the proper processing start position, and it is possible to prevent the occurrence of processing defects.

Further, for example, the movement amount (pushing amount) of the drill tip side support portion 2 detected by the movement amount detecting means is immediately (real time) determined by the movement amount determining means, and the movement amount detected by the movement amount detecting means is defined. When the value is exceeded, the movement amount determination means immediately outputs a signal to stop the movement, thereby preventing the drill tip side support portion 2 from moving more than the specified value and applying a load to the spindle head side. It is possible to prevent damage to the drill tip side support portion 2 and the tip box 7 provided at the tip portion of the spindle unit 10.

As described above, according to the present invention, even if a programming error or an operation error occurs in the disposition operation of the drill tip side support portion at the machining start position, the drill tip side support portion 2 provided at the tip portion of the spindle unit 10 It is an epoch-making machine tool that can prevent damage to the chip box 7 and the occurrence of processing defects.

Specific examples of the present invention will be described with reference to the drawings.

In this embodiment, the spindle head 1, the drill tip side support portion 2 that rotatably supports the tip side of the gun drill 20 provided on the spindle head 1 and comes into contact with the work 30 during machining, and the drill tip side support portion. A spindle unit 10 having a steady rest support portion 5 provided between 2 and the spindle head 1 to suppress rotational runout of the gun drill 20 and a work 30 are placed and the work 30 is moved to an appropriate position. A table unit 40 is provided, and when the drill tip side support portion 2 is arranged at the machining start position, the work 30 of the drill tip side support portion 2 when the drill tip side support portion 2 approaches the work 30. A function (approaching operation control function) that reduces the approach speed to the drill tip side support portion 2 and prevents (reduces) the collision of the drill tip side support portion 2 with the work 30 and the drill tip side support portion 2 are arranged at an appropriate machining start position. Drill tip side support collision prevention with a function (machining start position determination function) that confirms whether or not it is present before starting machining and prevents machining from starting in a state where it is arranged at an inappropriate machining start position. A system is provided, and before starting machining, the drill tip side support portion 2 that rotatably supports the tip side of the gun drill 20 is brought close to the work 30, and the drill tip side support portion 2 is pushed to the work 30 at a constant level. This is a machine tool that is arranged at a position where it is pressed by force (machining start position) and that the drill tip side support portion 2 is pressed against the work 30 for machining.

Hereinafter, each component of the present embodiment will be described in detail.

The spindle head 1 has a spindle 1a rotatably provided at the tip thereof, and is configured to move forward and backward in the spindle unit 10 by a ball screw mechanism (not shown), and movement in the vertical direction (Y-axis direction) is movement of the spindle unit 10. It is a configuration made by.

Specifically, as shown in FIG. 1, the spindle head 1 of this embodiment is slidably provided on a spindle head moving rail 6 juxtaposed with the screw shaft of the ball screw mechanism, and is a motor of the ball screw mechanism. It is configured to move forward or backward by the rotational movement of the screw shaft that is rotated by driving.

Further, the drill tip side support portion 2 is urged toward the tip side in the drill axial direction by a pressurized fluid so as to press against the work 30 with a constant pushing force during machining, and further abuts on the work 30 to attach the drill tip side. It is a retractable configuration that moves to the base end side in the drill axial direction against the force.

Specifically, as shown in FIG. 2, the drill tip side support portion 2 has an insertion hole 2a into which the gun drill 20 is inserted and is configured to be movable along the drill axis direction, and a main body portion 2A thereof. It consists of a guide portion 2B that guides the movement of the main body portion 2A. The main body portion 2A is provided on the guide portion 2B in a state of being prevented from coming off on the tip side in the drill axial direction, and hydraulic oil as a pressurized fluid is applied to the guide portion 2B. A hydraulic chamber 2b to be pressure-filled is provided, and the main body 2A is always urged toward the tip side in the drill axial direction by pressurizing the hydraulic oil press-fitted into the hydraulic chamber 2b.

Further, the guide portion 2B has a hydraulic oil supply flow path 2c that communicates with the hydraulic chamber 2b, and the hydraulic oil is pressure-flowed into the hydraulic chamber 2b through the hydraulic oil supply flow path 2c. Also, in this embodiment, a flow rate sensor 3 is provided in the hydraulic oil supply flow path 2c, and the flow rate sensor 3 is configured to detect the flow of the hydraulic oil.

Further, as shown in FIG. 1, the steady rest support portion 5 is arranged at a position where the gun drill 20 between the spindle head 1 and the tip box 7 is equally divided, and the steady rest portion synchronous movement mechanism (not shown) is used. It is configured to move in the direction of the drill axis while maintaining the position of equally dividing the gun drill 20 in synchronization with the forward movement of the spindle head 1.

Specifically, this embodiment includes three steady rest support portions 5, and each steady rest support portion 5 has a base portion 5a slidably provided on a moving rail 8 extending in the direction of the drill axis. The base portion 5a is detachably provided with a support portion 5b having a gun drill insertion hole for rotatably supporting the gun drill 20. The one on the tip side (drill tip side support side) moves at a lower speed, and synchronizes with the forward movement of the spindle head 1 while holding the position that equally divides the gun drill 20 between the spindle head 1 and the tip box 7. It is configured to move forward.

Further, the table unit 40 has an X-axis direction (horizontal direction), a Z-axis direction (front-back direction, specifically, a direction in which the table unit 40 is brought into contact with and separated from the drill tip side support portion 2), and a B-axis direction (rotational direction). It is configured to be movable to, and each operation is automatically controlled by a program.

That is, in this embodiment, the work 30 is moved with respect to the drill tip side support portion 2 by the movement of the spindle unit 10 in the Y-axis direction and the movement of the table unit 40 in the X-axis direction, the Z-axis direction, and the B-axis direction. The drill tip side support portion 2 is configured to be arranged at the machining start position by moving relative to each other.

Further, the drill tip side support collision prevention system includes approaching movement speed deceleration means, contact detecting means, moving amount detecting means, and moving amount determining means, and the approaching motion control function and machining start position determination described above by these means. It has a function, and even if a programming error occurs in the disposition operation of the drill tip side support portion 2 at the machining start position, it prevents the drill tip side support portion 2 from colliding with the work 30 and also prevents the drill tip side support portion 2 from colliding with the work 30. It is configured to prevent machining from starting in a state where the support portion 2 is arranged at an inappropriate machining start position.

Specifically, the approach moving speed decelerating means has a measuring unit 4 for measuring the separation interval between the drill tip side support portion 2 and the work 30, and the separation interval measured by the measuring unit 4 becomes a predetermined value. At that time, it is configured to slow down the approaching movement speed.

Further, in the present embodiment, the measuring unit 4 is a laser sensor, and the approaching moving speed decelerating means of the present embodiment uses the measuring unit 4 as a spindle unit 10 (specifically, a drill on the front side of the spindle unit 10). It is provided above the tip side support portion 2), and the distance between the drill tip side support portion 2 and the machined surface 30a of the work 30 is measured by irradiating a laser from the measuring unit 4 toward the machined surface 30a of the work 30. When the separation interval reaches a predetermined value (for example, 50 mm), a signal is output to the table unit movement control unit (not shown) that controls the movement of the table unit 40, and the table unit movement control unit that receives this signal is the table unit. It is configured to decelerate the movement speed of 40 (for example, decelerate to 600 mm / min).

In this embodiment, using this measuring unit 4, the drill tip side support portion 2 and the work 30 are used immediately after the start of processing (before the operation of arranging the drill tip side support portion 2 at the machining start position is started). It is configured to start the movement of the work 30 (table unit 40) after confirming the presence or absence of an obstacle between the and the work 30 and confirming that there is no obstacle.

Further, the contact detecting means detects the contact of the drill tip side support portion 2 with the work 30 when the drill tip side support portion 2 is arranged at the machining start position. The contact detection means uses the flow sensor 3 of the hydraulic mechanism of the drill tip side support portion 2, and the drill tip side support portion 2 is brought into the drill tip side support portion by the contact of the drill tip side support portion 2 with the work 30. The flow sensor 3 detects the flow of hydraulic oil generated by moving 2 toward the proximal end side in the drill axial direction against the pressing force of the hydraulic oil urging the tip side in the drill axial direction, and drills the timing of this detection. It is configured to detect as the timing of contact of the tip side support portion 2 with the work 30.

Further, the movement amount detecting means is the amount of movement of the drill tip side support portion 2 toward the base end side in the drill axial direction after the drill tip side support portion 2 comes into contact with the work 30, in other words, the drill tip side support portion. It detects the pushing amount of 2. In this embodiment, since the movement of the drill tip side support portion 2 is caused by the movement of the work 30, the movement amount is detected by using the movement data of the table unit 40 in the Z-axis direction.

Further, the movement amount determining means determines whether or not the movement amount detected by the movement amount detecting means is appropriate. In this embodiment, if the determination result of the movement amount determining means is OK, a drill is used. It is configured to determine that the tip side support portion 2 is arranged at the proper machining start position and proceed to the next processing, and in the case of NG, the processing is interrupted and an alarm is output.

Further, in this movement amount determining means, the movement amount (pushing amount) of the drill tip side support portion 2 detected by the movement amount detecting means is immediately detected (in real time), and the movement amount detected by the movement amount detecting means is used. It is configured to output a signal to stop the movement immediately when the specified value is exceeded.

Each processing operation during machining of the present embodiment provided with the above-mentioned drill tip side support collision prevention system will be described with reference to the processing state diagrams shown in FIGS. 2 to 7 and the flowcharts shown in FIGS. 8 and 9.

First, before the start of machining, the position where the cutting edge 20a of the gun drill 20 enters a predetermined amount (L1 in the figure) from the tip of the drill tip side support portion 2 by the operation of the operator (in this embodiment, the drill tip side support portion 2). The gun drill 20 is positioned so as to be 10 mm from the tip of the drill bit, and the position of the cutting edge 20a of the gun drill 20 at the machining start position is set in the program (for example, in this embodiment, the support portion 2 on the tip side of the drill). The position where the drill tip side is 5 mm inserted, that is, the state where the drill tip side support portion 2 is pushed in by 5 mm is set as the machining start position).

After the completion of the pre-machining preparation, the processing operation is started by inputting the processing start signal.

When the processing start signal is input, the measurement unit 4 (laser sensor) first operates to confirm the presence or absence of an obstacle between the drill tip side support unit 2 and the work 30. If no obstacle is detected in this obstacle confirmation, the table unit 40 starts moving and the work 30 approaches the drill tip side support portion 2, and if an obstacle is detected, the process is stopped. And output an alarm.

Further, in the approaching movement of the work 30 to the drill tip side support portion 2, as shown in FIG. 3, the separation interval between the drill tip side support portion 2 and the work 30 is measured by the measuring unit 4 (laser sensor). When the separation interval becomes the predetermined separation interval L2, the approach moving speed of the work 30 with respect to the drill tip side support portion 2 is reduced (for example, in this embodiment, when the separation interval becomes 50 mm, the work 30 The moving speed is reduced to 600 mm / min.)

Subsequently, the work 30 further moves closer to the drill tip side support portion 2 at this decelerated moving speed, and as shown in FIG. 4, when the work 30 comes into contact with the tip surface of the drill tip side support portion 2, this work The contact detecting means (flow sensor 3) detects the contact of the 30 with the drill tip side support portion 2, and the work 30 when the work 30 comes into contact with the drill tip side support portion 2 by this contact detecting means. The position in the Z-axis direction, specifically, the Z-axis coordinates of the table unit 40 are saved, and the movement of the spindle unit 10 in the Y-axis direction and the movement of the table unit 40 in the X-axis direction and the B-axis direction. The interlock is applied to the above, and the positions of the spindle unit 10 in the Y-axis direction and the table unit 40 in the X-axis direction and the B-axis direction are fixed.

After the contact detection means (flow rate sensor 3) detects the contact of the work 30 with the drill tip side support portion 2 and the Z-axis coordinates are saved, the cutting edge 20a of the gun drill 20 is set in the program for the work 30 ( Move to the base end side in the drill axial direction so as to be the machining start position (input), and push in the drill tip side support portion 2 as shown in FIG. 5 (in this embodiment, push in the set value programmed before the start of processing by 5 mm. .).

At this time, the amount of pushing of the support portion 2 on the drill tip side is detected immediately (in real time) by the movement data of the table unit 40 in the Z-axis direction as the amount of movement of the work 30 toward the base end side in the drill axial direction, and a programming error occurs. When the pushing amount of the drill tip side support portion 2 exceeds 5 mm, the pushing operation is stopped and an alarm is output.

Subsequently, the movement amount (pushing amount) of the support portion 2 on the drill tip side to the base end side in the drill axial direction after the contact with the work 30 when normally stopped is detected by the movement amount detecting means, and the movement amount detecting means is used. The movement amount determining means determines whether or not the movement amount (pushing amount) of the drill tip side support portion 2 detected in 1 is within an appropriate range (2 mm to 5 mm in the case of this embodiment) as shown in FIG. If it is within an appropriate range, it is determined that the drill tip side support portion 2 is in an appropriate machining start position state, and drilling is started as shown in FIG. 7.

If the amount of movement (pushing amount) of the support portion 2 on the tip side of the drill is out of the appropriate range, the drilling process is not started and an alarm is output.

Further, after the machining is completed, after the gun drill 20 is moved to the retracted position, the work 30 moves away from the drill tip side support portion 2 and moves to a predetermined position, and the work is completed.

In this embodiment, the case where the processing operation of arranging the drill tip side support portion 2 at the machining start position is an automatic operation by a program has been described, but this processing operation may be manually operated by an operator. Often, in the case of manual operation by an operator, the processing operation is performed according to the flowcharts shown in FIGS. 10 and 11.

The action and effect of this example configured as described above will be described below.

In this embodiment, when the drill tip side support portion 2 is arranged at the machining start position, the measuring section 4 measures the separation interval between the drill tip side support portion 2 and the machined surface 30a of the work 30, and the separation interval is measured. When becomes a predetermined value, a signal is output to the table unit movement control unit that controls the movement of the table unit 40, and the table unit movement control unit that receives this signal decelerates the movement speed of the table unit 40. The impact due to the contact with the drill tip side support portion 2 is reduced, and the damage due to the impact of the contact between the work 30 and the drill tip side support portion 2 is prevented.

Further, in this embodiment, when the drill tip side support portion 2 is arranged at the machining start position, the amount of movement toward the base end side in the drill axial direction after the work 30 comes into contact with the drill tip side support portion 2. That is, the pushing amount of the drill tip side support portion 2 is detected by the moving amount detecting means, and whether or not the pushing amount of the drill tip side support portion 2 detected by the moving amount detecting means is within the specified value is determined by the moving amount determining means. Therefore, even if a programming error or an operation error occurs, it is prevented that the drill tip side support portion 2 is pushed more than specified, and the drill tip side support portion 2 is in an improper machining start position. It is a machine tool that prevents the start of machining in the machine tool and prevents damage to the tip of the spindle unit 10 and occurrence of machining defects due to programming mistakes and operation mistakes.

The present invention is not limited to the present embodiment, and the specific configuration of each constituent requirement can be appropriately designed.

1 Spindle head 2 Drill tip side support 3 Flow sensor 4 Measuring unit
10 spindle unit
20 drill
30 work

Claims (7)

A drill tip side support portion that rotatably supports the tip end side of the drill provided on the spindle head and comes into contact with the work during machining is provided, and this drill tip side support portion is urged toward the tip end side in the drill axial direction by a pressurized fluid. A machine tool for drilling that is configured to move toward the base end side in the drill axial direction against the urging by coming into contact with the work, and the drill tip side support portion and the work. The contact detecting means for detecting the contact with the drill, the moving amount detecting means for detecting the moving amount of the support portion on the drill tip side to the base end side in the drill axial direction after the contact, and the moving amount detecting means. A machine tool having a movement amount determining means for determining whether or not the detected movement amount is appropriate. In the machine tool according to claim 1, the contact detecting means includes a flow sensor, and the drill tip side support portion moves toward the base end side in the drill axial direction due to contact between the drill tip side support portion and the work. A machine tool characterized in that the flow of the pressurized fluid is detected by the flow sensor to detect the contact between the support portion on the tip side of the drill and the work. In the machine tool according to any one of claims 1 and 2, the movement amount detecting means is provided with the movement amount of the work toward the base end side in the drill axial direction, or the spindle head and the drill tip side support portion. A machine tool characterized in that it is configured to detect based on the amount of movement of the spindle unit to the tip side in the drill axis direction. In the machine tool according to any one of claims 1 to 3, the movement amount determining means has a movement amount of the drill tip side support portion to the base end side in the drill axial direction after the contact is a predetermined amount or more. A machine tool characterized in that it is configured to output a signal for stopping the movement of the support portion on the tip side of the drill when the drill tip side is supported. In the machine tool according to any one of claims 1 to 4, when the distance between the drill tip side support portion and the work becomes a predetermined distance, the approach moving speed between the drill tip side support portion and the work is reached. A machine tool characterized by being provided with an approaching speed decelerating means for decelerating. In the machine tool according to claim 5, the approach moving speed decelerating means has a measuring unit for measuring the separation interval between the drill tip side support portion and the work, and the separation interval measured by the measuring unit is predetermined. A machine tool characterized in that it is configured to reduce the approaching movement speed when the value is reached. A drill tip side support portion that rotatably supports the tip end side of the drill provided on the spindle head and comes into contact with the work during machining is provided, and this drill tip side support portion is urged toward the tip end side in the drill axial direction by a pressurized fluid. A machine tool for drilling that is configured to move toward the base end side in the drill axial direction against the urging by coming into contact with the work, and the drill tip side support portion and the work. It has a measuring unit that measures the distance between the drill and the drill, and when the distance measured by this measuring unit reaches a predetermined distance, the approach movement that slows down the approach movement speed between the drill tip side support portion and the work is reduced. A machine tool characterized by being equipped with a speed deceleration means.

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