JPH0615948U - Tool holder positioning pin device - Google Patents

Abstract

(57) [Abstract] [Purpose] When the cutting reaction force is large or when high pressure coolant is supplied, the pressing force against the positioning pin is strengthened so that it can withstand the reaction force and pressure, and Facilitates automatic tool change. [Structure] A spring 7 having a weak spring force and a strong spring 8 are used as springs for elastically pressing the positioning pin 3.
Is weakened when is pushed for a certain stroke 7
Only the locating pin 3 acts on the locating pin 3 so that a strong spring force of the spring 8 is applied from a position beyond a certain stroke.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a positioning pin device for a tool holder such as a coolant supply type tool holder used in a machine tool such as a machining center, an angular head or a multi-axis head having a positioning pin for preventing rotation.

[0002]

[Prior art]

 Conventionally, for example, as disclosed in Japanese Utility Model Publication No. 63-7488, Japanese Utility Model Publication No. 63-34832, or Japanese Utility Model Publication No. 63-44736, a coolant supply type tool holder, an angular head, or a reversible tap holder is disclosed. In this case, the positioning pin is fitted to the housing mounted via the auxiliary bearing, and this positioning pin is pressed by the spring force to fit the tip part to the positioning block near the spindle of the machine tool. I am trying to do it.

FIG. 3 shows such a conventional example, in which a housing 2 is mounted around a holder main body 1 of a tool holder via an auxiliary bearing, and one side of the housing 2 is slidable in the axial direction. The positioning pin 3 is fitted and elastically pressed by the spring 4. The positioning pin 3 also serves as an oil supply pin in the case of a coolant supply type tool holder.

A stopper 5 is provided on the positioning pin 3, and the stopper 5 is normally engaged with an engagement groove 6 provided on a flange of the holder body 1 so that the holder body 1 and the housing 2 are fixed in the rotational direction. However, when the holder body 1 is attached to the spindle of the machine tool, the tip of the positioning pin 3 fits into the hole of the positioning block provided near the spindle, and the positioning is performed against the elastic force of the spring 4. The pin 3 is pushed in by a certain stroke to disengage the stopper 5 from the engagement groove 6, and the holder body 1 becomes rotatable with respect to the housing 2.

In a normal case, the pressing force of the positioning pin 3 by the spring 4 is about 2 to 5 kgf. However, when a cutting reaction force is strongly received or a high pressure coolant is supplied, the reaction force or pressure is applied. Since the positioning pin 3 has to be strongly pressed against this, a pressing force of about 50 kgf is required. Further, since the housing 2 and the holder body 1 are aligned by using the stroke of the positioning pin 3, the stroke of the positioning pin 3 is usually required to be about 5 to 8 mm.

Conventionally, since only one spring 4 is normally used to apply a pressing force to the positioning pin 3, the relationship between the spring force and the stroke is linear as shown in FIG. .

[0007]

[Problems to be solved by the device]

 As described above, when the cutting reaction force is large or when high-pressure coolant is supplied, a strong pressing force of about 50 kgf against the positioning pin 3 is required, but on the other hand, the pressing force is large. Then, since the positioning pin 3 is offset from the center of the tool holder, a tipping moment acts on the tool holder, and when the tool is replaced by the ATC (automatic tool change) mechanism, the tool holder is pushed to the regular clamp position. There is a problem that various problems occur in the ATC operation such as failure to do so.

An object of the present invention is to provide a positioning pin device for a tool holder that can apply a sufficient pressing force to the positioning pin and can perform ATC operation without hindrance.

[0009]

[Means for Solving the Problems]

 A positioning pin device for a tool holder according to the present invention to achieve the above object is a positioning pin in which a housing is mounted around a holder body through an auxiliary bearing, and is slidably fitted to one side of the housing. In a tool holder in which the tip of each of the pins is pressed against the corresponding positioning block, the spring that presses the positioning pin consists of a weak spring and a strong spring that act in stages according to the stroke of the positioning pin. It is a thing.

[0010]

[Action]

 With the tool holder positioning pin device having the above-mentioned configuration, when the tool holder is mounted on the spindle of the machine tool, only a weak spring force acts on the positioning pin in the initial stroke of the positioning pin, so the pressing reaction force The tilt amount of the tool holder caused by the overturning moment due to is also kept within a certain angle, and since a strong spring force also acts from the position where a certain stroke is exceeded, the positioning pin is positioned with a sufficiently strong pressing force when the mounting is completed. Is pressed against the block.

[0011]

【Example】

 The present invention will be described in detail with reference to the illustrated embodiment. 1 shows an embodiment of a positioning pin device for a tool holder according to the present invention, and the same reference numerals as those in FIG. 3 denote the same or equivalent members. Here, a weak spring 7 having a relatively small spring force and a strong spring 8 having a considerably large spring force are used as the springs that apply the pressing force to the positioning pin 3, and these spring forces are applied to the positioning pin 3. It works in a stepwise manner depending on the stroke.

A large-diameter hole 10 having an inner diameter slightly larger than that of the fitting hole 9 of the housing 2 into which the positioning pin 3 is fitted is provided, and the large-diameter hole 10 is slidably fitted in the large-diameter hole 10. A seat plate 11 and a strong spring 8 that presses the seat plate 11 are accommodated, and the strong spring 8 is in a state in which the seat plate 11 is pressed against a step portion 12 formed between the fitting hole 9 and the large diameter hole 10. However, normally, the spring force of the strong spring 8 does not act on the positioning pin 3 at all. A hole 11a is formed in the center of the seat plate 11, a small diameter shaft portion 3a integral with the positioning pin 3 passes through the hole 11a, and a weak spring 7 is fitted around the small diameter shaft portion 3a. Between the cross section 3b of the positioning pin 3 and the cover plate 13 of the large diameter hole 10, the positioning pin 3 is elastically pressed in the left direction in FIG.

The interval S between the cross section 3 b of the positioning pin 3 and the seat plate 11 is set so as to occupy most of the entire stroke of the positioning pin 3. For example, when the stroke of the positioning pin 3 is 8 mm, the space S is about 7 mm.

Normally, the protrusion amount of the positioning pin 3 is limited by the engagement between the stopper 5 and the engagement groove 6 shown in FIG. 3, and in this state, only the spring force of the weak spring 7 determines the position. It acts on the female pin 3.

Therefore, when the tool holder is mounted on the spindle of the machine tool, the tip of the positioning pin 3 comes into contact with the positioning block and is gradually pushed in from about 8 mm before the regular clamp position, but its stroke During the initial stage, that is, until the cross section 3b of the positioning pin 3 comes into contact with the seat plate 11 in FIG. 1, only the spring force of the weak spring 7 acts on the positioning pin 3, so that the pressing reaction force The amount of tilt of the tool holder generated from the overturning moment can be kept within a certain angle, and the tool holder can be smoothly inserted into the spindle. From the position after a certain stroke, that is, the position where the cross section 3b abuts against the seat plate 11, the spring force of the strong spring 8 acts in addition to the spring force of the weak spring 7, so that the positioning pin 3 The pressing force related to is rapidly increased.

FIG. 2 shows the relationship between the stroke and the spring force when the stroke of the positioning pin 3 is 8 mm and the interval S in FIG. 1 is 7 mm, and from a position after a certain stroke (7 mm 3). , Shows that the spring force increases rapidly. In practice, it is preferable to adjust the position where the spring force becomes high to a position about 0.5 to 1 mm before the insertion end point.

From this position onward, the tool holder is pulled in by a large force of 1 to 2 tons by the tool clamp mechanism in the spindle, so that the positioning pin 3 is pushed to a predetermined position in spite of a strong spring force. .

Therefore, the ATC operation of the tool holder in which the spring force with respect to the positioning pin is strengthened has been conventionally restricted by the ATC mechanism. However, in the case of the present invention, the ATC mechanism can be sufficiently operated without changing the design of the ATC mechanism. The pressing force can be increased, and it can be used for other types of tool holders and tool heads that use positioning pins.

Also in the case of the coolant supply type tool holder, when the coolant pressure is increased, the positioning pin may be pushed back by the pressure and the coolant may leak, but in the case of the present invention, a sufficient pressing force is secured. Therefore, such an accident can be prevented.

In the above-described embodiment, the case where the number of springs that apply the pressing force to the positioning pin 3 is two is shown, but it may be two or more. Further, as the mechanism for causing the spring forces of the weak spring 7 and the strong spring 8 to act in stages in accordance with the stroke of the positioning pin 3, various means other than the embodiment can be used.

[0021]

[Effect of device]

 As described above, the tool holder positioning pin device according to the present invention is sufficiently resistant to the reaction force and pressure when the pressing force against the positioning pin is a large cutting reaction force or when high-pressure coolant is supplied. You can make it strong enough to withstand. In addition, since only a weak spring force acts until the positioning pin passes a certain stroke, the problem that the ATC operation is hindered by the overturning moment that occurs when the pressing force is increased is improved. It

[Brief description of drawings]

FIG. 1 is a sectional view of an example.

FIG. 2 is a graph showing a relationship between a stroke of a positioning pin and a spring force.

FIG. 3 is a sectional view of a conventional example.

FIG. 4 is a graph showing a relationship between a stroke of a positioning pin and a spring force in a conventional example.

[Explanation of symbols]

 1 Holder Main Body 2 Housing 3 Positioning Pin 5 Stopper 7 Weak Spring 8 Strong Spring 9 Fitting Hole 10 Large Diameter Hole 11 Seat Plate 12 Step 13 Cover Plate

Claims (1)

[Scope of utility model registration request] 1. A tool in which a housing is mounted around a holder main body through an auxiliary bearing, and a tip of a positioning pin slidably fitted to one side of the housing is pressed against a corresponding positioning block. In the holder, the spring for elastically pressing the positioning pin comprises a weak spring and a strong spring that act in stages according to the stroke of the positioning pin.