JPH0929507A - Bush device for automatic lathe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bush device for an automatic lathe which is capable of stopping rotation of a main spindle when a galling phenomenon happens between a bush and a workpiece material. SOLUTION: A bush proper 1 is equipped with a bush holder 30 and a torque limiter device 10 having an engagement part 13 which checks rotation of the bush holder 30 by engaging with the bush holder 30 when torque is not greater than a predetermined value. Along with this, a sensor device 20 is provided for detecting disengagement caused by displacement of the engagement part 13 of the torque limiter device 10 or rotation of the bush holder 30 caused by the disengagement when the bush holder 30 receives greater torque than the predetermined torque from a bush 56, and the sensor device 20 is connected in such a manner that detected signals are transmitted to a control device for stopping rotation of a main spindle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bushing device for an automatic lathe.

[0002]

2. Description of the Related Art As a bushing device for an automatic lathe, for example, a device having a mechanism as shown in FIG. 4 of the accompanying drawings is widely known.

In FIG. 4, a spindle unit 51 grips and rotates a rod-shaped work material 52 and sends it out in an axial direction at a predetermined time.

The bush body 53 is fixed to the machine body, and the bush holder 55 is fixed to the bush body 53 by tightening the set bolt 54.

On the other hand, the bush 56 has a contact support part 56A on the inner surface of the front part in the axial direction (the part to the left in FIG. 4), and the contact support part 56A rotates and moves the work piece 52 in the axial direction. The work material 52 is supported so as to allow. The bush 56 and its contact support portion 56A have slits 57 formed at a plurality of positions in the circumferential direction toward the front end, and
The outer circumference of the front portion has a tapered portion 58 whose diameter is increased toward the front end. A threaded portion 59 is formed on the outer periphery of the rear portion of the bush 56, and a sleeve portion 60A of the gear 60 is screwed therein.

At the lower part of the bush body 53, a rod-shaped adjusting member 64 having a rotary operation portion 61 at a front end, a step portion 62 at an intermediate position, and a gear portion 63 at a rear end is inserted. Are fixed by fixing bolts 65.

In such a device, the contact support portion 56A
The delicate clearance between the work material 52 and the work material 52 is made by tightening the fixing bolt 65 and then rotating the adjusting member 64 by applying a rotational force to the rotary operation portion 61. When the adjusting member 64 rotates, the gear 60 meshing with the gear portion 63 of the adjusting member 64 rotates, and the bush holder 55 screwed with the sleeve portion 60A of the gear 60 with the screw portion 59.
Moves in the axial direction. Since the bush 56 is in contact with the bush holder 55 at the tapered portion 58, the axial movement of the bush holder 55 causes elastic deformation in the slit 57 in the radial direction, and the clearance is adjusted.
After the adjustment, the fixing bolt 65 maintains the state.

Further, in the figure, reference numeral 66 is a cutting tool, which receives cutting oil during cutting. The cutting oil forms a lubricating oil film in the clearance between the contact support portion 56A of the bush 56 and the work material 52, and maintains the smooth rotation of the work material 52.

[0009]

As described above, in the conventional apparatus, the lubricating oil film formed in the adjusted clearance between the contact support portion 56A of the bush 56 and the work material 52 is used for cutting. The material 52 rotates smoothly.

However, if the clearance is not appropriate, the cutting load is excessive due to damage of the cutting tool, or the cutting oil is insufficient, the normal lubrication state is lost and the contact support portion 56A of the bush and the work material are made of metal. A so-called "galling phenomenon" occurs in which contact occurs, heat is generated, and welding occurs. If you continue to operate the machine without noticing this galling phenomenon in the initial stage, you will not be able to perform normal cutting and will not only produce defective products, but also the bushes will be damaged and the cutting oil will catch fire due to heat generation. It could cause a fire.

The present invention solves the problems of the conventional device, and provides a bushing device for an automatic lathe which can stop the machine when a galling phenomenon occurs and a torque over the set value acts on the bushing. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION An automatic lathe bush device of the present invention comprises a bush for supporting a work material so as to be rotatable about its axis and to be guided in the axial direction at a predetermined time,
A bush holder that adjusts the clearance between the bush and the work material and a bush body that supports the bush holder so as to prevent rotation of the bush holder are provided.

The bush body is provided with a torque limiter device and a sensor device. The torque limiter device is attached to the bush body, and the engaging portion engages with the bush holder to prevent rotation of the bush holder. However, when the torque larger than the set torque is received from the bush holder, the engagement is performed. The engagement with the bush holder of the section is released. When the engagement is released, the bush holder can be rotated. The sensor device is designed to detect the disengagement of the engaging part or the rotation of the bush holder due to the disengagement, and the detection signal is connected to the control device so as to stop the rotation of the main shaft. ing.

Thus, according to the present invention, when a galling phenomenon occurs and the bush holder receives a torque larger than the set value, the spindle is stopped by the signal of the sensor to prevent defective products and accidents.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG.
An embodiment of the present invention will be described based on the above.

FIG. 1 is a half sectional front view showing an embodiment of the present invention. In the figure, the same parts as those of the conventional device shown in FIG. To do.

In FIG. 1, a torque limiter device 10 and a sensor device 20 are attached to the bush body 1.

The torque limiter device 10 is guided by a nut 11 screwed into a threaded portion formed in a hole penetrating in the radial direction at least at one location on the outer periphery of the bush body 1, and a guide hole 11A of the nut 11. And a push pin 12 to be driven. The push pin 12 is provided with an engaging portion 13 having a curved end portion forming a part of a spherical surface at a lower end portion thereof, and a stepwise intermediate portion 14 at an upper portion thereof, and further at an upper end of the intermediate portion 14. The stepped portion 14A constitutes a guided portion 15 having a small diameter and is guided by the guide hole 11A.

The intermediate portion 14 is provided with a compression spring 16 as an elastic member, which comes into contact with the lower surface 11B of the nut 11 and the stepped rear surface 13A of the engaging portion 13 to push the pin 1.
The second engaging portion 13 is biased downward. Note that nut 1
The stopper ring 17 fitted to the guided portion 15 at the portion projecting outwardly from the position 1 is for preventing the nut 11 and the push pin 12 from being separated from each other during assembly.

The stepped portion 14A at the upper end of the intermediate portion 14 comes into contact with the lower surface 11A of the nut 3 when the push pin 4 is pushed upward with respect to the nut 3 and regulates it as the upper limit of the upward movement. It is for.

The sensor device 20 has a main body portion 21 having a threaded portion formed on the outer surface of the upper portion, and the main body portion 21 is inserted into a hole portion which is formed by penetrating the bush body 1 in the radial direction. It is attached to a predetermined position by a nut 23 via a support plate 22 arranged on the outer surface of the bush body 1. The main body 21 has an internal space and is a hemispherical detection unit 24.
Are housed so as to project downward, and are urged downward by an urging member (not shown) arranged in the internal space.
As a matter of course, the detection unit does not drop from the main body unit 21. A switch for detecting when the detection unit 24 is pushed up by a predetermined amount against the urging force of the urging member is housed in the main body portion 21. It is connected to a control device that stops rotation. The predetermined push-up amount of the detection unit 24 for operating the switch is the screw 2
It can be changed by adjusting item 3.

The sensor device 20 is protected from dust, oil, water, etc. from the outside by a cover 27 attached to the bush body 1 via a support plate 22 with bolts 26.

On the other hand, the bush holder 30 has a cone-shaped, for example, cone-shaped first conical recess 31 and a second conical recess 32 on its outer peripheral surface at positions corresponding to the torque limiter device 10 and the sensor device 20. The first conical recess 31 is formed.
The engaging portion 1 of the push pin 12 of the torque limiter device 10 is
The curved end portion 3 and the second conical recess 32 are biased and engaged with the detection portion 24 of the sensor device 20, respectively.

In this example, the clearance between the contact support portion 56 of the bush 56 and the work material 52 is appropriately adjusted by the adjusting member 64 and maintained in that state by the fixing bolt 65, as in the conventional device. To be done. Further, the engaging portion 13 of the push pin 12 of the torque limiter device 10 is in the first conical recess 31 and prevents the bush holder 30 from rotating.

However, in the present example, when the above-mentioned galling phenomenon occurs in the above clearance due to some inconvenience, the work material 5 rotationally driven by the main shaft.
2 tries to rotate the bush holder 30 by transmitting all or part of the driving torque to the bush holder 30 via the bush 56.

When the bush holder 30 receives the rotating torque, the push pin 12 of the torque limiter device 10 is engaged with the engaging portion 1 by the push pin 12.
It is pushed up by the first conical recess 31 at the curved end of 3. When the above rotation torque becomes equal to or more than the set value, the push pin 12
Is released upward from the first conical recess 31 and the engagement with the bush holder 30 is released. As a result of this disengagement, the bush holder 30 becomes rotatable, so the sensor device 2
The detection unit 24 of 0 is also pushed up by the second conical recess 32,
At this point, the switch of the sensor device is activated and the control device stops the rotation of the spindle.

This example can be modified as shown in FIG. For example, the torque limiter device 10 does not have to have the structure as shown in FIG. 1, but may be a ball plunger or a spring plunger in which a ball 36 as a curved end is housed at the tip of a screw body 35 in which an elastic member is already built. You can also do it. It is also possible to use a pin that is sheared with a predetermined torque. In this case, the sensor device 20 may be the same as that shown in FIG.

Further, as shown in FIG. 3, according to the present invention, the movement of the push pin 12 of the torque limiter device 10 shown in FIG. 1 may be directly detected by the sensor device 40. In the example of FIG. 3, a proximity switch or the like is used as the detection unit 41, and the back surface 13A of the curved end 13 of the push pin 12 described above is used.
The proximity switch may be activated when is raised to a predetermined position. The position of the detector 41 is fixed by a screw 42.

[0029]

As described above, according to the present invention, when the bush has a galling phenomenon and the bush holder receives a torque of a set value or more, this is detected and the rotation of the spindle is stopped. It is possible to prevent the occurrence of an accident, damage to a machine, and an accident.

[Brief description of drawings]

FIG. 1 is a half cross-sectional front view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a modification of a torque limiter device applicable to the device of FIG.

FIG. 3 is a sectional view showing another embodiment of the present invention.

FIG. 4 is a partial cross-sectional front view of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bush body 10 Torque limiter device 13 Engagement part 20 Sensor device 24 Detection part 30 Bush holder 31 First conical recessed part 32 Second conical recessed part 41 Detection part 52 Work material 56 Bushing

Claims (3)

[Claims] 1. A bush for supporting a work material rotatably around its axis and guiding the work piece in the axial direction at a predetermined time, a bush holder for adjusting a clearance between the bush and the work material, and In a bushing device of an automatic lathe having a bushing body supporting the bushing holder so as to prevent the rotation of the bushing holder, a bushing body is engaged with the bushing holder at a torque less than a set torque to prevent the bushing holder from rotating. A torque limiter device having a coupling portion is provided, and when the bush holder receives a torque larger than the set torque from the bush, the engagement is released by the displacement of the engagement portion of the torque limiter device or the engagement is released. Is provided with a sensor device for detecting the rotation of the bush holder by means of the sensor device. Bushing device for an automatic lathe, characterized in that it is connected so as to be transmitted to a control device for automatic lathe. 2. A torque limiter device comprising: a movable engaging portion having a curved end portion that engages with a first conical concave portion formed on an outer surface of a bush holder; and the engaging portion having the first conical concave portion. When the bush holder receives a torque larger than the set torque, the engaging portion resists the urging force of the elastic member and has the first conical shape. The urging force is set so that it is pushed out of the recess and is disengaged from the first conical recess, and the sensor device is
The torque limiter device is disengaged from the bush holder, and the torque limiter device is disengaged from the second holder formed in the outer peripheral surface of the bush holder. 2. The bush device for an automatic lathe according to claim 1, wherein when the bush holder is rotated, the detection portion moves against the urging force to generate an engagement release signal. 3. A torque limiter device comprising: a movable engaging portion having a curved end portion that engages with a first conical concave portion formed on an outer surface of a bush holder; and the engaging portion having the first conical concave portion. When the bush holder receives a torque larger than the set torque, the engaging portion resists the urging force of the elastic member and has the first conical shape. The urging force is set so that it is pushed out of the recess and is disengaged from the first conical recess, and the sensor device is
The bushing device for an automatic lathe according to claim 1, wherein the detector directly detects the movement of the engaging portion when the torque limiter device is disengaged.