JP2002066862A - Overrun preventing device for machine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a machine tool. SOLUTION: An overrun preventing device is provided with a saddle 3; and a tool rest 4 linearly moving in the direction of an X-axis to the saddle 3. A lever type limit switch is mounted on the tool rest 4. A dog 7 to operate the limit switch 5 when the tool rest 4 reaches a stroke end is mounted movably in the moving direction of the tool rest 4. A lever 15 for driving a dog provided at one end part with a roller 14A is pivotally mounted on the middle part of the length of the saddle 3. A press member 16 making contact with the other end part of the lever 15 for driving a dog is situated at the tool rest 4. A roller guide groove 13 extending in a direction orthogonal to the moving direction of the dog 7 and guiding the roller 14A of the lever 15 for driving the dog is formed in the dog 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an overrun prevention device for a machine tool.

[0002]

2. Description of the Related Art For example, in a numerical control (NC) lathe, a tool rest is mounted on a tool rest to prevent an overrun of a tool rest moving on a saddle in an X-axis direction orthogonal to a Z-axis direction which is a main axis direction. And a pair of dogs attached to the saddle at predetermined intervals in the X-axis direction and operating the limit switch,
An overrun prevention device provided with a mechanical dead stopper provided between the saddle and the tool rest so as to be located on the outer side in the X-axis direction of both dogs is provided. Both dogs are provided at both ends of the effective stroke range when processing the tool rest.

In the limit switch, when a lever swings a predetermined angle from a non-operating position, it reaches an operating position and normally contacts open, and furthermore, the lever swings a predetermined angle in the same direction from the operating position to be separated. A so-called contact forcible opening type is used in which the contact is forcibly opened when the contact reaches a position, even if the contact is fixed.

[0004]

However, in the conventional overrun prevention device, the lever of the limit switch can be swung only by the movement of the tool post.
The travel distance of the tool rest between the operation position and the release position of the lever is relatively large. In addition, the distance between the dead stoppers needs to be relatively large due to the increase in the moving distance. Therefore,
There is a problem that the dimension in the X-axis direction of the NC lathe must be increased.

[0005] An object of the present invention is to provide an overrun prevention device which can solve the above-mentioned problem and can reduce the size of a machine tool.

[0006]

According to the first aspect of the present invention, there is provided an overrun prevention device for a machine tool, wherein a first member and a second member which move linearly with respect to the first member.
A lever-type limit switch is attached to one of the two members, and a dog that activates the limit switch when the second member reaches the stroke end is attached to the other member. In the overrun prevention device of the machine tool, between the two members, at least after the lever tip of the limit switch contacts the dog and the lever swings by a predetermined angle, the movement of the second member, the limit switch and the dog, A moving means for relatively moving the lever in the direction in which the swing of the lever is advanced is provided.

According to the first aspect of the present invention, the limit switch is configured such that when the lever swings a predetermined angle from the non-operation position, the lever reaches the operation position and the contact is normally opened, and the lever is further moved in the same direction from the operation position by the predetermined angle A so-called forced contact separation type is used, in which the contact is forcibly opened even if the contacts are stuck when swinging to reach the separation position. In the first aspect of the present invention, the position at which the lever swings by a predetermined angle means the operating position of the forced-opening type limit switch. The moving means only needs to relatively move the limit switch and the dog in the direction in which the lever swings, at least after the lever reaches the operating position. For example, after the lever contacts the dog, the limit switch and the dog may be relatively moved in the direction in which the lever swings.

According to the overrun prevention device of the first aspect of the present invention, the second member is moved between the first and second members after at least the tip of the limit switch contacts the dog and the lever swings by a predetermined angle. The movement means for relatively moving the limit switch and the dog in the direction in which the lever swings is provided by the movement of the lever, so that in addition to the movement of the second member, the limit switch and the dog are moved by the relative movement of the limit switch and the dog. The swing of the switch lever is advanced. Therefore, the moving distance of the tool post to the disengaged position after the lever swings by a predetermined angle, that is, the moving distance of the tool post from the operating position to the disengaged position is smaller than that of the conventional device. Become smaller. In addition, the distance between the dead stoppers can be made smaller than that of the conventional device by reducing the moving distance. As a result, the size of the second member of the machine tool in the moving direction can be reduced.

According to a second aspect of the present invention, there is provided an overrun prevention device for a machine tool according to the first aspect, wherein a limit switch is attached to the second member, and
A dog is attached to the member so as to be movable in the movement direction of the second member, and a dog driving lever having a roller at one end is pivotally attached to the first member at an intermediate portion of its length. A roller guide is provided on the two members, which is provided with a pressing member which abuts against and pushes the other end of the dog driving lever, extends in the dog in a direction perpendicular to the moving direction of the dog, and guides the roller of the dog driving lever. Is provided.

According to a third aspect of the present invention, there is provided an overrun prevention device for a machine tool according to the first aspect of the present invention, wherein a limit switch is attached to the second member and the first member has a first switch.
A dog is movably attached to the member in the direction of movement of the second member, a pinion is rotatively attached to the first member, and the second member and the dog extend in the direction of movement of the second member and engage with the pinion. Is provided.

According to the second and third aspects of the present invention, it can be realized with a simple configuration and at low cost. In addition, the overrun prevention device is a part that is rarely used originally, but requires reliability in an emergency.
According to the second and third aspects of the present invention, high reliability can be ensured with a simple configuration, and high accuracy is not required for manufacturing, so that manufacturing cost is reduced.

[0012]

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

FIG. 1 shows an entire NC lathe provided with an overrun prevention device according to the present invention, FIGS. 2 and 3 show essential parts thereof, and FIG. 4 shows a case where a tool rest moves beyond an effective stroke range. Indicates the status. In the following description, the left side of FIG. 1 is referred to as front, the opposite side is referred to as rear, the front side of FIG. 1 (left side in FIG. 3) is referred to as left, and the opposite side is referred to as right.

As shown in FIG. 1, the NC lathe comprises an inclined bed (1), a spindle (2) provided on the bed (1), and a spindle (2) on the bed (1) in the axial direction. A saddle (3) (first member) arranged to move in the Z-axis direction,
(3) A tool rest (4) (second member) arranged on the saddle (3) so as to move in the X-axis direction perpendicular to the Z-axis direction with respect to the saddle (3).

A roller lever type limit switch (5) of a contact forced forcible type is mounted on the left side of the tool rest (4) with the lever (6) facing downward. On the left side of the saddle (3), a pair of dogs (7) for operating the limit switch (5) are located at both ends of the effective stroke range in the X-axis direction when processing the tool post (4). Installed. Although not shown, a mechanical dead stopper is provided between the saddle (3) and the tool rest (4) so as to be located outside the dogs (7) in the X-axis direction. When the turret (4) reaches the end (front end) in the X-direction of the effective stroke range, the tip of the lever (6) is connected to the front dog (5). 7), and also the tool post
(4) is the end (rear end) in the X + direction of the effective stroke range
Is reached, the tip of the lever (6) comes into contact with the dog (7) on the rear side.

As shown in FIG. 2, the upper surface of the dog (7) is parallel to the guide surface of the tool rest (4) of the saddle (3), but its inner end in the X-axis direction (the front dog ( An inclined surface (7a) that is inclined downward inward in the X-axis direction is formed at the rear end portion in (7) and the front end portion in the rear dog (7).

After the tip of the lever (6) of the limit switch (5) contacts each dog (7) between the saddle (3) and the tool post (4), the tool post (4) moves Limit switch (5)
And a moving means for relatively moving each dog (7) in a direction in which the swing of the lever (6) is advanced. Less than,
The moving means that operates when the tool post (4) reaches the end of the effective stroke range in the X-direction will be described.

As shown in FIGS. 2 and 3, the saddle (3)
A guide (9) having a guide groove (8) extending in the X-axis direction on the left side is fixed to the left side surface of the dog, so that the dog (7) can move in the X-axis direction into the guide groove (8). Has been put in. On the upper and lower opening edges of the guide groove (8) in the guide (9), ridges (9a) protruding inward of the groove are integrally formed,
By fitting these ridges (9a) into the concave grooves (10) formed respectively on the upper and lower surfaces of the dog (7), the dog (7) is prevented from falling out of the guide groove (8). I have. A spring support member (11) is fixed to an end (front end) in the X-direction of the guide groove (8) of the guide (9), and the spring support member (11) and the dog (7) are fixed to each other. In between, dog (7) is always X-
A tension coil spring (12) biasing in the direction is mounted.
The direction perpendicular to the X-axis direction on the left side of the dog (7) (Fig. 2
The roller guide groove (13) is formed to extend in the up-down direction. A dog drive lever (15) having rollers (14A) and (14B) at both ends is provided at a position above the guide groove (8) on the left side surface of the guide (9) in the left-right direction at the center of the length. It is pivotally mounted about an extending axis. The roller (14A) at one end of the dog drive lever (15) is
The roller guide groove (13) is rotatably fitted in the roller guide groove (13).
The roller (14B) at the other end of the dog drive lever (15) abuts on the left side of the tool rest (4) on the X-direction side of the limit switch (5) and pushes it forward. Pressing member
(16) is fixed. The pressing member (16) is connected to the dog driving lever (1) at the same time that the roller (6a) at the tip of the lever (6) of the limit switch (5) comes into contact with the inclined surface (7a) of the dog (7).
It comes into contact with the roller (14B) of 5).

In the NC lathe having the above structure, the tool rest (4)
Moves to the end in the X-direction of the effective stroke range, when the roller (6a) at the tip of the lever (6) of the limit switch (5) comes into contact with the inclined surface (7a) of the dog (7). At the same time, the pressing member (16) of the tool post (4) is
The roller contacts the roller (14B) of 5) (see FIG. 2). When the tool post (4) moves in the X-direction beyond the effective stroke range, the lever (6) of the limit switch (5) is pushed by the dog (7), and the pressing member (16) is started. ) Pushes the roller (14B) of the dog driving lever (15), and the dog driving lever (15) is rotated counterclockwise in FIG. When the dog drive lever (15) rotates, the roller (14
A) pushes the side surface on the X + direction side of the roller guide groove (13), and the dog (7) starts to move in the direction opposite to the moving direction of the tool post (4). When the lever (6) of the limit switch (5) swings by a predetermined angle and reaches the operating position (see FIG. 4 (a)), the contact of the limit switch (5) is opened to the feed device of the tool post (4). Is stopped.

When the power supply to the feeder is not stopped even after the switch to the operating position, such as when the contact point of the limit switch (5) is fixed, the tool rest (4) moves further in the same direction. Then, the lever (6) of the limit switch (5) is further swung by the dog (7). At the same time, the dog drive lever (15) is further rotated by the pressing member (16), so that the dog (7) is also
The lever further moves in the direction opposite to the moving direction of (4), whereby the swing of the lever (6) of the limit switch (5) is advanced. When the lever (6) of the limit switch (5) swings to the disengagement position (see FIG. 4B), the contact of the limit switch (5) is forcibly disengaged and the power supply to the feeder is stopped. Then, the tool rest (4) is stopped.

In the above, the dog driving lever (15)
Is pivotally attached to the guide (9) at the center of the length, so that the lever (6) of the limit switch (5)
After a) touches the slope (7a) of the dog (7), the dog
(7) moves by a distance equal to the moving distance of the tool post (4), and the moving distance of the tool post (4) until the limit switch (5) reaches the disengagement position is determined by the dog (7). This is １ ／ of the case where no movement occurs.

When the tool rest (4) is returned within the effective stroke range, the dog (7) is returned to the original state by the extension coil spring (12).

Although detailed illustration is omitted, the NC lathe includes:
Moving means is also provided which is activated when the tool rest (4) reaches the end in the X + direction of the effective stroke range. This moving means is symmetric (left-right symmetric) with respect to the X-axis direction with respect to the moving means which operates when reaching the end in the X-direction described above.

FIG. 5 shows another embodiment of the overrun prevention device according to the present invention.

In FIG. 5, a pinion (20) is mounted on the left side of the guide (9) above the guide groove (8) so as to be rotatable around an axis extending in the left-right direction. . A rack (21) having teeth on the upper surface of the dog (7) extending in the X-axis direction and meshing with the teeth of the pinion (20).
Are formed. A rack (22) having teeth extending in the X-axis direction and meshing with the teeth of the pinion (20) is fixed to the left side surface of the tool rest (4). The teeth of the rack (21) formed on the dog (7) are always meshed with the teeth of the pinion (20). The teeth of the rack (22) fixed to the tool post (4)
The roller (6a) at the end of the lever (6) of the limit switch (5)
When it comes into contact with the inclined surface (7a) of the dog (7), the pinion (2
It is designed to mesh with tooth 0). In addition, turret (4)
Is within the effective stroke range, the dog (7) is urged forward by the tension coil spring (12) for positioning. Other configurations are the same as those of the above-described first embodiment, and the same components are denoted by the same reference numerals.

In this embodiment, when the tool rest (4) moves to the end of the effective stroke range in the X-direction, the lever (6) of the limit switch (5) and the roller (6a) at the tip end
Comes into contact with the inclined surface (7a) of the dog (7) and
The teeth of the rack (22) of (4) mesh with the teeth of the pinion (20).
When the turret (4) moves in the X-direction beyond the effective stroke range, the lever (6) of the limit switch (5) is pushed by the dog (7), and the turret (4) is moved. )
The pinion (20) is rotated in the direction indicated by the arrow in FIG. 5 by the rack (22), and the rack (2) is rotated by the rotation of the pinion (20).
The dog (7) starts to move via 1) in the direction opposite to the moving direction of the tool post (4). When the lever (6) of the limit switch (5) swings by a predetermined angle and switches to the operating position, the tool post (4)
Of the feeding device is stopped.

When the power supply to the feeder is stopped even after the switch to the operating position, such as when the contact point of the limit switch (5) is fixed, the tool rest (4) moves further in the same direction. Then, the lever (6) of the limit switch (5)
Is further rocked by the dog (7). At the same time, the action of the two racks (21) (22) and the pinion (20) also causes the dog (7) to move further in the direction opposite to the direction of movement of the tool post (4), whereby the limit switch (5 The swing of the lever (6) is advanced. When the lever (6) of the limit switch (5) swings to the open position, the limit switch (5)
Are forcibly opened, the power supply to the feeder is stopped, and the tool rest (4) is stopped.

When the tool rest (4) is returned to the effective stroke range, the two racks (21) and (22) and the pinion (20)
Returns the dog (7) to its original state.

In the above two embodiments, the roller (6a) at the tip of the lever (6) of the limit switch (5) is connected to the dog (7).
When the lever (6) swings from the non-operation position to the operation position, the dog (7) moves in the direction opposite to the direction of movement of the tool post (4) even when the lever (6) swings from the non-operation position to the operation position. As a result, the travel distance of the tool post (4) between the time when the lever (6) of the limit switch (5) reaches the operation position from the non-operation position becomes shorter than that of the conventional device, and as a result, the NC lathe Can be further reduced in the X-axis direction, but is not limited to this. After the lever (6) of the limit switch (5) reaches the operating position, the dog (7) is moved to the position of the tool post (4). What is necessary is just to be able to move in the direction opposite to the moving direction.

In the above two embodiments, two dogs (7) are attached to the saddle (3), and the tool post (4)
Is equipped with one limit switch (5), but conversely, two limit switches (5) are attached to the saddle (3) and one dog (7) is attached to the tool post (4). May be attached. In this case, as the moving means, those substantially similar to those in the above two embodiments can be used, but this moving means moves the dog (7) in the same direction as the moving direction of the tool post (4). It is configured to be moved.

Further, in the above two embodiments,
The overrun prevention device according to the present invention is applied to an NC lathe including a saddle (3) and a tool post (4) that moves with respect to the saddle (3). However, the present invention is not limited to this. The prevention device can be applied to a machine tool having a first member and a second member that moves linearly with respect to the first member.

[Brief description of the drawings]

FIG. 1 shows an N having an overrun prevention device according to the present invention.
It is a side view of C lathe.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a view corresponding to FIG. 2, showing a state when the tool rest moves beyond the effective stroke range.

FIG. 5 is a diagram corresponding to FIG. 2, showing another embodiment of the present invention.

[Explanation of symbols]

 (3): Saddle (first member) (4): Tool post (second member) (5): Lever type limit switch (6): Lever (7): Dog (13): Roller guide groove (14A) ) (14B): Roller (15): Lever for dog drive (16): Pressing member (20): Pinion (21) (22): Rack

Claims (3)

[Claims] A first member and a second member that moves linearly with respect to the first member; a lever-type limit switch is attached to one of the two members; In a machine tool overrun prevention device in which a dog that activates a limit switch when the second member reaches the stroke end is attached to the member, at least the end of the lever of the limit switch contacts the dog between the two members. After the lever swings by a predetermined angle,
An overrun prevention device for a machine tool provided with a moving means for relatively moving a limit switch and a dog in a direction in which the swing of a lever is advanced by movement of a second member. 2. A dog driving device having a limit switch attached to a second member, a dog attached to the first member movably in a moving direction of the second member, and a roller provided at one end of the first member. A lever is pivotally mounted at an intermediate portion of its length, and a second member is provided with a pressing member that abuts against and pushes the other end of the dog driving lever, and the dog makes a right angle to the dog moving direction. 2. The overrun prevention device for a machine tool according to claim 1, further comprising a roller guide extending in the direction and guiding the roller of the dog driving lever. 3. A limit switch is attached to the second member, a dog is attached to the first member so as to be movable in the moving direction of the second member, and a pinion is attached to the first member so as to be rotatable. 2. The overrun prevention device for a machine tool according to claim 1, wherein the member and the dog are each provided with a rack extending in the moving direction of the second member and engaging with the pinion.